2022
Haochen, L; Thekinen, J; Mollaoglu, S; Tang, D; Yang, J; Cheng, Y; Liu, H; Tang, J
Toward Annotator Group Bias in Crowdsourcing Conference Forthcoming
60th Annual Meeting of the Association for Computational Linguistics (ACL), Dublin, Forthcoming.
Abstract | BibTeX | Tags: Information Systems, Machine Learning | Links:
@conference{nokey,
title = {Toward Annotator Group Bias in Crowdsourcing},
author = {Haochen, L and J Thekinen and Mollaoglu, S and Tang, D and Yang, J and Cheng, Y and Liu, H and Tang, J},
url = {https://josephdthekinen.com/wp-content/uploads/2022/03/Toward_Annotator_Group_Bias_in_Crowdsourcing____ACL_camera_ready.pdf},
year = {2022},
date = {2022-05-23},
urldate = {2022-05-23},
booktitle = {60th Annual Meeting of the Association for Computational Linguistics (ACL)},
address = {Dublin},
abstract = {Crowdsourcing has emerged as a popular approach for collecting annotated data to train supervised machine learning models. However, annotator bias can lead to defective annotations. Though there are a few works investigating individual annotator bias, the group effects in annotators are largely overlooked. In this work, we reveal that annotators within the same demographic group tend to show consistent group bias in annotation tasks and thus we conduct an initial study on annotator group bias. We first empirically verify the existence of annotator group bias in various real-world crowdsourcing datasets. Then, we develop a novel probabilistic graphical framework GroupAnno to capture annotator group bias with an extended Expectation Maximization (EM) algorithm. We conduct experiments on both synthetic and realworld datasets. Experimental results demonstrate the effectiveness of our model in modeling annotator group bias in label aggregation and model learning over competitive baselines.},
keywords = {Information Systems, Machine Learning},
pubstate = {forthcoming},
tppubtype = {conference}
}
Crowdsourcing has emerged as a popular approach for collecting annotated data to train supervised machine learning models. However, annotator bias can lead to defective annotations. Though there are a few works investigating individual annotator bias, the group effects in annotators are largely overlooked. In this work, we reveal that annotators within the same demographic group tend to show consistent group bias in annotation tasks and thus we conduct an initial study on annotator group bias. We first empirically verify the existence of annotator group bias in various real-world crowdsourcing datasets. Then, we develop a novel probabilistic graphical framework GroupAnno to capture annotator group bias with an extended Expectation Maximization (EM) algorithm. We conduct experiments on both synthetic and realworld datasets. Experimental results demonstrate the effectiveness of our model in modeling annotator group bias in label aggregation and model learning over competitive baselines.
Wang, W; Thekinen, J; Liu, X; Liu, Z; Tang, J
Learning from Imbalanced Crowdsourced Labeled Data Conference Forthcoming
Proceedings of the 2022 SIAM International Conference on Data Mining (SDM), SIAM Forthcoming.
Abstract | BibTeX | Tags: | Links:
@conference{nokey,
title = {Learning from Imbalanced Crowdsourced Labeled Data},
author = {W Wang and J Thekinen and X Liu and Z Liu and J Tang},
url = {https://josephdthekinen.com/wp-content/uploads/2021/12/learning_imbalanced_crowdsoured_data.pdf},
year = {2022},
date = {2022-04-28},
booktitle = {Proceedings of the 2022 SIAM International Conference on Data Mining (SDM)},
organization = {SIAM},
abstract = {Crowdsourcing has proven to be a cost-effective way to meet the demands for massive labeled training data in supervised deep learning models. However, the obtained crowdsourced labels are often inconsistent and noisy due to cognitive and expertise differences among crowd workers. Existing approaches either infer latent true labels from noisy crowdsourced labels or learn a discriminative model directly from the crowdsourced labeled data, assuming the latent true label distribution is class-balanced. Unfortunately, in many real-world applications, the true label distribution typically is imbalanced across classes involved in the collected data. Therefore, in this paper, we address the problem of learning from crowdsourced labeled data with an imbalanced true label distribution. We propose a new framework, named “Learning from Imbalanced Crowdsourced Labeled Data” (ICED), which simultaneously infers true labels from imbalanced crowdsourced labeled data and achieves high accuracy on downstream tasks such as classification. The ICED framework consists of two modules— a true label inference module and a synthetic data generation module— that augment each other iteratively. Extensive experiments conducted on both synthetic and real-world datasets demonstrate the effectiveness of the ICED framework. We will release datasets and code used for evaluation based on the acceptance of this paper.},
keywords = {},
pubstate = {forthcoming},
tppubtype = {conference}
}
Crowdsourcing has proven to be a cost-effective way to meet the demands for massive labeled training data in supervised deep learning models. However, the obtained crowdsourced labels are often inconsistent and noisy due to cognitive and expertise differences among crowd workers. Existing approaches either infer latent true labels from noisy crowdsourced labels or learn a discriminative model directly from the crowdsourced labeled data, assuming the latent true label distribution is class-balanced. Unfortunately, in many real-world applications, the true label distribution typically is imbalanced across classes involved in the collected data. Therefore, in this paper, we address the problem of learning from crowdsourced labeled data with an imbalanced true label distribution. We propose a new framework, named “Learning from Imbalanced Crowdsourced Labeled Data” (ICED), which simultaneously infers true labels from imbalanced crowdsourced labeled data and achieves high accuracy on downstream tasks such as classification. The ICED framework consists of two modules— a true label inference module and a synthetic data generation module— that augment each other iteratively. Extensive experiments conducted on both synthetic and real-world datasets demonstrate the effectiveness of the ICED framework. We will release datasets and code used for evaluation based on the acceptance of this paper.
2021
Haochen, L; Thekinen, J; Mollaoglu, S; Tang, D; J, Yang; Y, Cheng; H, Liu; J, Tang
Toward Annotator Group Bias in Crowdsourcing Online
2021, visited: 14.10.2021, (Cite as arXiv:2110.08038).
Abstract | BibTeX | Tags: Machine Learning | Links:
@online{liu2021toward,
title = {Toward Annotator Group Bias in Crowdsourcing},
author = {Haochen, L and Thekinen, J and Mollaoglu, S and Tang, D and Yang J and Cheng Y and Liu H and Tang J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2021_Haochen_Toward-Annotator-Group-Bias-in-Crowdsourcing.pdf},
year = {2021},
date = {2021-10-14},
urldate = {2021-10-14},
abstract = {Crowdsourcing has emerged as a popular approach for collecting annotated data to train supervised machine learning models. However, annotator bias can lead to defective annotations. Though there are a few works investigating individual annotator bias, the group effects in annotators are largely overlooked. In this work, we reveal that annotators within the same demographic group tend to show consistent group bias in annotation tasks and thus we conduct an initial study on annotator group bias. We first empirically verify the existence of annotator group bias in various real-world crowdsourcing datasets. Then, we develop a novel probabilistic graphical framework GroupAnno to capture annotator group bias with a new extended Expectation Maximization (EM) training algorithm. We conduct experiments on both synthetic and real-world datasets. Experimental results demonstrate the effectiveness of our model in modeling annotator group bias in label aggregation and model learning over competitive baselines.},
note = {Cite as arXiv:2110.08038},
keywords = {Machine Learning},
pubstate = {published},
tppubtype = {online}
}
Crowdsourcing has emerged as a popular approach for collecting annotated data to train supervised machine learning models. However, annotator bias can lead to defective annotations. Though there are a few works investigating individual annotator bias, the group effects in annotators are largely overlooked. In this work, we reveal that annotators within the same demographic group tend to show consistent group bias in annotation tasks and thus we conduct an initial study on annotator group bias. We first empirically verify the existence of annotator group bias in various real-world crowdsourcing datasets. Then, we develop a novel probabilistic graphical framework GroupAnno to capture annotator group bias with a new extended Expectation Maximization (EM) training algorithm. We conduct experiments on both synthetic and real-world datasets. Experimental results demonstrate the effectiveness of our model in modeling annotator group bias in label aggregation and model learning over competitive baselines.
Bayhan, H; Ma, Y; Thekinen, J; Tang, J; Mollaoglu, S
Using Jaccard Similarity to Identify New Issues from AEC Project Team Meeting Minutes Conference
ASCE International Conference on Computing and Civil Engineering, Orland - Florida, American Society of Civil Engineers 2021.
Abstract | BibTeX | Tags: | Links:
@conference{nokey,
title = {Using Jaccard Similarity to Identify New Issues from AEC Project Team Meeting Minutes},
author = {Bayhan, H and Ma, Y and Thekinen, J and Tang, J and Mollaoglu, S},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2021_i3ce_Using-Jaccard-Similarity-to-Identify-New-Issues-from-AEC-Project-Team-Meeting-Minutes.pdf},
year = {2021},
date = {2021-02-02},
urldate = {2021-05-01},
booktitle = {ASCE International Conference on Computing and Civil Engineering, Orland - Florida},
organization = {American Society of Civil Engineers},
abstract = {Keeping track of issues and their documentation in Architecture, Engineering, and Construction (AEC) projects demand significant amounts of time, budget, and effort. While various types of documents and software aid coordination in AEC projects, project team meeting minutes, developed as a follow-up to periodic project team meetings, continue to be the most common and prominent type of documentation across project types for recording team communications, tasks, and assignments. Presently, identifying unique project issues and tracking their progress from meeting minutes is a manual process that is time-consuming and susceptible to error. Dynamic organizational structures to project teams, varying document formats from project to project and even within projects based on leading organizations during delivery, and changing milestones from different projects create challenges in automating this task. This study aims to automate the identification of project issues and track resolution timelines using project team meeting minute documents via the Jaccard Similarity method. In this study, over 50 AEC project team meeting minutes documents of varying formats from three different projects of various sizes were collected, automatically converted, and coded to train the Jaccard Similarity model for detecting new and continuing issues. Specifically, we treated individual entries in each meeting minute document as an issue data point on the date they first appeared and used key information from those entries as features. We modeled the task as a classification problem, labeling each item to either a new or a continued issue. Accuracy, precision, recall, and F1 parameters were tested, and the accuracy rates of 81.86% to 94.18% were obtained. The study provides the groundwork to automate the analysis of important information in project meeting minutes that include but are not limited to issue complexity, detection of bottlenecks, and analysis of expertise assignments for issue resolution.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Keeping track of issues and their documentation in Architecture, Engineering, and Construction (AEC) projects demand significant amounts of time, budget, and effort. While various types of documents and software aid coordination in AEC projects, project team meeting minutes, developed as a follow-up to periodic project team meetings, continue to be the most common and prominent type of documentation across project types for recording team communications, tasks, and assignments. Presently, identifying unique project issues and tracking their progress from meeting minutes is a manual process that is time-consuming and susceptible to error. Dynamic organizational structures to project teams, varying document formats from project to project and even within projects based on leading organizations during delivery, and changing milestones from different projects create challenges in automating this task. This study aims to automate the identification of project issues and track resolution timelines using project team meeting minute documents via the Jaccard Similarity method. In this study, over 50 AEC project team meeting minutes documents of varying formats from three different projects of various sizes were collected, automatically converted, and coded to train the Jaccard Similarity model for detecting new and continuing issues. Specifically, we treated individual entries in each meeting minute document as an issue data point on the date they first appeared and used key information from those entries as features. We modeled the task as a classification problem, labeling each item to either a new or a continued issue. Accuracy, precision, recall, and F1 parameters were tested, and the accuracy rates of 81.86% to 94.18% were obtained. The study provides the groundwork to automate the analysis of important information in project meeting minutes that include but are not limited to issue complexity, detection of bottlenecks, and analysis of expertise assignments for issue resolution.
Thekinen, J; Grogan, P
Information Exchange Patterns in Digital Engineering: An Observational Study Using Web-Based Virtual Design Studio Journal Article
In: Journal of Computing and Information Science in Engineering, 21 (4), pp. 041012, 2021.
Abstract | BibTeX | Tags: Decentralized Design, Digital Engineering, Information Systems | Links:
@article{thekinen2021information,
title = {Information Exchange Patterns in Digital Engineering: An Observational Study Using Web-Based Virtual Design Studio},
author = {Thekinen, J and Grogan, P},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2021_JCISE_Information-Exchange-Patterns-in-Digital-Engineering-An-Observational-Study-Using-Web-Based-Virtual-Design-Studio.pdf},
doi = {10.1115/1.4050087},
year = {2021},
date = {2021-02-01},
urldate = {2021-02-01},
journal = {Journal of Computing and Information Science in Engineering},
volume = {21},
number = {4},
pages = {041012},
publisher = {American Society of Mechanical Engineers},
abstract = {This paper performs an observational human subjects study to investigate how design teams use an information system to exchange, store, and synthesize information in an engineering design task. Framed through the lens of decision-based design, a surrogate design task models an aircraft design problem with 12 design parameters across four roles and six system-level functional requirements. A virtual design studio provides a browser-based interface for four participants in a 30-min design session. Data collected across 10 design sessions provide process factors about communication patterns and outcome factors about the resulting design. Correlation analysis shows a positive relationship between design iteration and outcome performance but a negative relationship between chat messages and outcome performance. Discussion explains how advances in information exchange, storage, and synthesis can support future design activities.},
keywords = {Decentralized Design, Digital Engineering, Information Systems},
pubstate = {published},
tppubtype = {article}
}
This paper performs an observational human subjects study to investigate how design teams use an information system to exchange, store, and synthesize information in an engineering design task. Framed through the lens of decision-based design, a surrogate design task models an aircraft design problem with 12 design parameters across four roles and six system-level functional requirements. A virtual design studio provides a browser-based interface for four participants in a 30-min design session. Data collected across 10 design sessions provide process factors about communication patterns and outcome factors about the resulting design. Correlation analysis shows a positive relationship between design iteration and outcome performance but a negative relationship between chat messages and outcome performance. Discussion explains how advances in information exchange, storage, and synthesis can support future design activities.
2020
Thekinen, J; Moolchandani, K; Panchal, J; DeLaurentis, D
Modeling Airlines’ Route Selection Decisions Under Competition: A Discrete-Games-Based Model Journal Article
In: Journal of Air Transportation, 28 (1), pp. 3-14, 2020.
Abstract | BibTeX | Tags: Complex Networked Systems, Game Theory | Links:
@article{thekinen2020modeling,
title = {Modeling Airlines’ Route Selection Decisions Under Competition: A Discrete-Games-Based Model},
author = {Thekinen, J and Moolchandani, K and Panchal, J and DeLaurentis, D},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2018_JAT_Modeling-Airlines-Route-Selection-Decisions-Under-Competition-A-Discrete-Games-Based-Model.pdf},
doi = {10.2514/1.D0153},
year = {2020},
date = {2020-02-01},
urldate = {2020-02-01},
journal = {Journal of Air Transportation},
volume = {28},
number = {1},
pages = {3-14},
abstract = {To analyze the effects of policies within the air transportation network, there is a need to model how policies affect the decisions made by airlines. Because airline decision making is based on proprietary information, such models need to rely on openly available data sources. In this paper, openly available data from the Bureau of Transportation Statistics are used to develop a predictive model of airline route selection decisions. The proposed model accounts for airline competition and models parameters such as operating cost, which can be influenced by policymakers. This paper illustrates the model using a dataset from two major airlines in U.S. domestic air transportation network. The dataset and the cost model are used for Bayesian estimation of model parameters, which are then used to predict the effects of cost and demand on the evolution of the network topology. The proposed model is found to be more accurate than competing models that do not consider the competition. From the estimates obtained on preference parameters, it is found that decreasing the operating cost and increasing the market demand increase the probability of operating service on the route for airlines, and the operating cost has a greater effect than market demand and route distance on the route selection decisions.},
keywords = {Complex Networked Systems, Game Theory},
pubstate = {published},
tppubtype = {article}
}
To analyze the effects of policies within the air transportation network, there is a need to model how policies affect the decisions made by airlines. Because airline decision making is based on proprietary information, such models need to rely on openly available data sources. In this paper, openly available data from the Bureau of Transportation Statistics are used to develop a predictive model of airline route selection decisions. The proposed model accounts for airline competition and models parameters such as operating cost, which can be influenced by policymakers. This paper illustrates the model using a dataset from two major airlines in U.S. domestic air transportation network. The dataset and the cost model are used for Bayesian estimation of model parameters, which are then used to predict the effects of cost and demand on the evolution of the network topology. The proposed model is found to be more accurate than competing models that do not consider the competition. From the estimates obtained on preference parameters, it is found that decreasing the operating cost and increasing the market demand increase the probability of operating service on the route for airlines, and the operating cost has a greater effect than market demand and route distance on the route selection decisions.
2019
Thekinen, J; Datta, N
Rayleigh-Ritz Method-based Analysis of Dry Coupled Horizontal-Torsional-Warping Vibration of Rectelliptic Open-section Containership Bare-hulls Journal Article
In: Applied Ocean Research, 86 , pp. 73–86, 2019.
Abstract | BibTeX | Tags: | Links:
@article{thekinen2019rayleigh,
title = {Rayleigh-Ritz Method-based Analysis of Dry Coupled Horizontal-Torsional-Warping Vibration of Rectelliptic Open-section Containership Bare-hulls},
author = {Thekinen, J and Datta, N},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2019_AOR_Rayleigh-Ritz-method-based-analysis-of-dry-coupled-horizontal-torsionalwarping-vibration-of-rectelliptic-open-section-containership-bare-hulls.pdf},
doi = {10.1016/j.apor.2019.01.032},
year = {2019},
date = {2019-11-02},
journal = {Applied Ocean Research},
volume = {86},
pages = {73--86},
publisher = {Elsevier},
abstract = {The coupled horizontal-torsional-warping vibration of a thin-walled open-section 7800 TEU container ship barehull, modelled as a non-uniform girder, is analysed by the efficient energy-based Rayleigh-Ritz method, in order to generate the dry asymmetric vibration frequencies. Since the centre of gravity is within the hull and the shear centre is below the keel, the horizontal and torsional modes of vibration are highly coupled. An open section is also prone to warping. In a novel attempt, the bare-hull geometry is generated mathematically, using sectionwise closed-form semi super-ellipses (Lame’s curves). The main dimensions, weight distributions, and fineness ratios are preserved, and closed-form expressions of sectional properties become available in the process. The hull has arbitrarily (non-mathematically) varying mass, bending stiffness, warping stiffness, and shear stiffness distributions along the length. The non-uniform beam modeshape in horizontal/torsional vibration is assumed to be a weighted sum of the uniform beam horizontal/torsional modeshapes. Several benchmark cases of simpler geometry have been analysed first, for both torsion-warping vibration, and coupled horizontal-torsional-warping vibration. Pontoon approximation of the containership has been analysed and validated. Subsequently, the coupled dry vibration frequencies are obtained for the open deck non-uniform girder, and compared with published results.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The coupled horizontal-torsional-warping vibration of a thin-walled open-section 7800 TEU container ship barehull, modelled as a non-uniform girder, is analysed by the efficient energy-based Rayleigh-Ritz method, in order to generate the dry asymmetric vibration frequencies. Since the centre of gravity is within the hull and the shear centre is below the keel, the horizontal and torsional modes of vibration are highly coupled. An open section is also prone to warping. In a novel attempt, the bare-hull geometry is generated mathematically, using sectionwise closed-form semi super-ellipses (Lame’s curves). The main dimensions, weight distributions, and fineness ratios are preserved, and closed-form expressions of sectional properties become available in the process. The hull has arbitrarily (non-mathematically) varying mass, bending stiffness, warping stiffness, and shear stiffness distributions along the length. The non-uniform beam modeshape in horizontal/torsional vibration is assumed to be a weighted sum of the uniform beam horizontal/torsional modeshapes. Several benchmark cases of simpler geometry have been analysed first, for both torsion-warping vibration, and coupled horizontal-torsional-warping vibration. Pontoon approximation of the containership has been analysed and validated. Subsequently, the coupled dry vibration frequencies are obtained for the open deck non-uniform girder, and compared with published results.
Thekinen, J; Datta, N
Wave-induced Flexural Response of Idealized Non-uniform Hull Girder in Random Seas Journal Article
In: Marine Systems & Ocean Technology, 14 (1), pp. 12-22, 2019.
Abstract | BibTeX | Tags: | Links:
@article{nokey,
title = {Wave-induced Flexural Response of Idealized Non-uniform Hull Girder in Random Seas},
author = {Thekinen, J and Datta, N},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2019_MSOT_Wave-induced-flexural-response-of-idealized-non-uniform-hull-girder-in-random-seas.pdf},
doi = {10.1007/s40868-017-0038-y},
year = {2019},
date = {2019-09-12},
journal = {Marine Systems & Ocean Technology},
volume = {14},
number = {1},
pages = {12-22},
abstract = {The aim is to analyze the wave-induced vertical vibration of a non-prismatic mathematical hull in a stochastic sea, by normal mode analysis. The hull has been generated mathematically, to represent two distinct Indian merchant vessels: DS (Tanker) and SCIM (Containership). The body-plan, deck waterline, bow and stern profiles, have been modeled as semi-superellipses. These render non-uniform distributions of mass and stiffness over the ship-length. The energy-based Rayleigh–Ritz method has been used to analyze the idealized hull girder natural frequencies and modeshapes. The non-uniform beam modeshape is a weighted series sum of prismatic beam-free vibration modeshapes. The 2D added mass of superelliptic sections is formulated, solving the radiation boundary value problem by the constant strength source distribution method. The hull girder is subject to the Pierson–Moskowitz sea spectrum in fully loaded condition. The diffraction force is formulated through the Khaskind’s relations. The flexural response of the girder is evaluated by the modal superposition method. The response spectra have been generated for various sea states and ship speeds. The magnitudes of the maximum flexural/shear stress for each vessel are generated. The probability of shear/tensile failure is also estimated, giving insights into the hull structural design.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The aim is to analyze the wave-induced vertical vibration of a non-prismatic mathematical hull in a stochastic sea, by normal mode analysis. The hull has been generated mathematically, to represent two distinct Indian merchant vessels: DS (Tanker) and SCIM (Containership). The body-plan, deck waterline, bow and stern profiles, have been modeled as semi-superellipses. These render non-uniform distributions of mass and stiffness over the ship-length. The energy-based Rayleigh–Ritz method has been used to analyze the idealized hull girder natural frequencies and modeshapes. The non-uniform beam modeshape is a weighted series sum of prismatic beam-free vibration modeshapes. The 2D added mass of superelliptic sections is formulated, solving the radiation boundary value problem by the constant strength source distribution method. The hull girder is subject to the Pierson–Moskowitz sea spectrum in fully loaded condition. The diffraction force is formulated through the Khaskind’s relations. The flexural response of the girder is evaluated by the modal superposition method. The response spectra have been generated for various sea states and ship speeds. The magnitudes of the maximum flexural/shear stress for each vessel are generated. The probability of shear/tensile failure is also estimated, giving insights into the hull structural design.
2018
Thekinen, J
Mechanism Design for Complex Systems: Bipartite Matching of Designers and Manufacturers, and Evolution of Air Transportation Networks PhD Thesis
Purdue University Graduate School, 2018.
Abstract | BibTeX | Tags: | Links:
@phdthesis{thekinen2018mechanism,
title = {Mechanism Design for Complex Systems: Bipartite Matching of Designers and Manufacturers, and Evolution of Air Transportation Networks},
author = {Thekinen, J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2018_PhD_Mechanism-Design-for-Complex-Systems-Bipartite-Matching-of-Designers-and-Manufacturers-and-Evolution-of-Air-Transportation-Networks.pdf},
year = {2018},
date = {2018-12-18},
school = {Purdue University Graduate School},
abstract = {A central issue in systems engineering is to design systems where the stakeholders do not behave as expected by the systems designer. Usually, these stakeholders have different and often conflicting objectives. The stakeholders try to maximize their individual objective and the overall system do not function as expected by the systems designers.
We specifically study two such systems- a) cloud-based design and manufacturing system (CBDM) and b) Air Transportation System (ATS). In CBDM, two stakeholders with conflicting objectives are designers trying to get their parts printed at the lowest possible price and manufacturers trying to sell their excess resource capacity at maximum profits. In ATS, on one hand, airlines make route selection decision with the goal of maximizing their market share and profits and on the other hand regulatory bodies such as Federal Aviation Administration tries to form policies that increase overall welfare of the people.
The objective in this dissertation is to establish a mechanism design based framework: a) for resource allocation in CBDM, and b) to guide the policymakers in channeling the evolution of network topology of ATS.
This is the first attempt in literature to formulate the resource allocation in CBDM as a bipartite matching problem with designers and manufacturers forming two distinct set of agents. We recommend best mechanisms in different CBDM scenarios like totally decentralized scenario, organizational scenario etc. based on how well the properties of the mechanism meet the requirements of that scenario. In addition to analyzing existing mechanisms, CBDM offers challenges that are not addressed in the literature. One such challenge is how often should the matching mechanism be implemented when agents interact over a long period of time. We answer this question through theoretical propositions backed up by simulation studies. We conclude that a matching period equal to the ratio of the number of service providers to the arrival rate of designers is optimal when service rate is high and a matching period equal to the ratio of mean printing time to mean service rate is optimal when service rate is low.
In ATS, we model the evolution of the network topology as the result of route selection decisions made by airlines under competition. Using data from historic decisions we use discrete games to model the preference parameters of airlines towards explanatory variables such as market demand and operating cost. Different from the existing literature, we use an airport presence based technique to estimate these parameters. This reduces the risk of over-fitting and improves prediction accuracy. We conduct a forward simulation to study the effect of altering the explanatory variables on the Nash equilibrium strategies. Regulatory bodies could use these insights while forming policies.
The overall contribution in this research is a mechanism design framework to design complex engineered systems such as CBDM and ATS. Specifically, in CBDM a matching mechanism based resource allocation framework is established and matching mechanisms are recommended for various CBDM scenarios. Through theoretical and simulation studies we propose the frequency at which matching mechanisms should be implemented in CBDM. Though these results are established for CBDM, these are general enough to be applied anywhere matching mechanisms are implemented multiple times. In ATS, we propose an airport presence based approach to estimate the parameters that quantify the preference of airlines towards explanatory variables. },
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
A central issue in systems engineering is to design systems where the stakeholders do not behave as expected by the systems designer. Usually, these stakeholders have different and often conflicting objectives. The stakeholders try to maximize their individual objective and the overall system do not function as expected by the systems designers.
We specifically study two such systems- a) cloud-based design and manufacturing system (CBDM) and b) Air Transportation System (ATS). In CBDM, two stakeholders with conflicting objectives are designers trying to get their parts printed at the lowest possible price and manufacturers trying to sell their excess resource capacity at maximum profits. In ATS, on one hand, airlines make route selection decision with the goal of maximizing their market share and profits and on the other hand regulatory bodies such as Federal Aviation Administration tries to form policies that increase overall welfare of the people.
The objective in this dissertation is to establish a mechanism design based framework: a) for resource allocation in CBDM, and b) to guide the policymakers in channeling the evolution of network topology of ATS.
This is the first attempt in literature to formulate the resource allocation in CBDM as a bipartite matching problem with designers and manufacturers forming two distinct set of agents. We recommend best mechanisms in different CBDM scenarios like totally decentralized scenario, organizational scenario etc. based on how well the properties of the mechanism meet the requirements of that scenario. In addition to analyzing existing mechanisms, CBDM offers challenges that are not addressed in the literature. One such challenge is how often should the matching mechanism be implemented when agents interact over a long period of time. We answer this question through theoretical propositions backed up by simulation studies. We conclude that a matching period equal to the ratio of the number of service providers to the arrival rate of designers is optimal when service rate is high and a matching period equal to the ratio of mean printing time to mean service rate is optimal when service rate is low.
In ATS, we model the evolution of the network topology as the result of route selection decisions made by airlines under competition. Using data from historic decisions we use discrete games to model the preference parameters of airlines towards explanatory variables such as market demand and operating cost. Different from the existing literature, we use an airport presence based technique to estimate these parameters. This reduces the risk of over-fitting and improves prediction accuracy. We conduct a forward simulation to study the effect of altering the explanatory variables on the Nash equilibrium strategies. Regulatory bodies could use these insights while forming policies.
The overall contribution in this research is a mechanism design framework to design complex engineered systems such as CBDM and ATS. Specifically, in CBDM a matching mechanism based resource allocation framework is established and matching mechanisms are recommended for various CBDM scenarios. Through theoretical and simulation studies we propose the frequency at which matching mechanisms should be implemented in CBDM. Though these results are established for CBDM, these are general enough to be applied anywhere matching mechanisms are implemented multiple times. In ATS, we propose an airport presence based approach to estimate the parameters that quantify the preference of airlines towards explanatory variables.
We specifically study two such systems- a) cloud-based design and manufacturing system (CBDM) and b) Air Transportation System (ATS). In CBDM, two stakeholders with conflicting objectives are designers trying to get their parts printed at the lowest possible price and manufacturers trying to sell their excess resource capacity at maximum profits. In ATS, on one hand, airlines make route selection decision with the goal of maximizing their market share and profits and on the other hand regulatory bodies such as Federal Aviation Administration tries to form policies that increase overall welfare of the people.
The objective in this dissertation is to establish a mechanism design based framework: a) for resource allocation in CBDM, and b) to guide the policymakers in channeling the evolution of network topology of ATS.
This is the first attempt in literature to formulate the resource allocation in CBDM as a bipartite matching problem with designers and manufacturers forming two distinct set of agents. We recommend best mechanisms in different CBDM scenarios like totally decentralized scenario, organizational scenario etc. based on how well the properties of the mechanism meet the requirements of that scenario. In addition to analyzing existing mechanisms, CBDM offers challenges that are not addressed in the literature. One such challenge is how often should the matching mechanism be implemented when agents interact over a long period of time. We answer this question through theoretical propositions backed up by simulation studies. We conclude that a matching period equal to the ratio of the number of service providers to the arrival rate of designers is optimal when service rate is high and a matching period equal to the ratio of mean printing time to mean service rate is optimal when service rate is low.
In ATS, we model the evolution of the network topology as the result of route selection decisions made by airlines under competition. Using data from historic decisions we use discrete games to model the preference parameters of airlines towards explanatory variables such as market demand and operating cost. Different from the existing literature, we use an airport presence based technique to estimate these parameters. This reduces the risk of over-fitting and improves prediction accuracy. We conduct a forward simulation to study the effect of altering the explanatory variables on the Nash equilibrium strategies. Regulatory bodies could use these insights while forming policies.
The overall contribution in this research is a mechanism design framework to design complex engineered systems such as CBDM and ATS. Specifically, in CBDM a matching mechanism based resource allocation framework is established and matching mechanisms are recommended for various CBDM scenarios. Through theoretical and simulation studies we propose the frequency at which matching mechanisms should be implemented in CBDM. Though these results are established for CBDM, these are general enough to be applied anywhere matching mechanisms are implemented multiple times. In ATS, we propose an airport presence based approach to estimate the parameters that quantify the preference of airlines towards explanatory variables.
Thekinen, J; Han, Y; Panchal, J
Designing Market Thickness and Optimal Frequency of Multi-Period Stable Matching in Cloud-Based Design and Manufacturing Conference
International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Quebec City, Canada, 51722 , American Society of Mechanical Engineers 2018.
Abstract | BibTeX | Tags: Cloud-based Design and Manufacturing, Mechanism Design | Links:
@conference{thekinen2018designing,
title = {Designing Market Thickness and Optimal Frequency of Multi-Period Stable Matching in Cloud-Based Design and Manufacturing},
author = {Thekinen, J and Han, Y and Panchal, J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2018_IDETC_DESIGNING-MARKET-THICKNESS-AND-OPTIMAL-FREQUENCY-OF-MULTI-PERIOD-STABLE-MATCHING-IN-CLOUD-BASED-DESIGN-AND-MANUFACTURING.pdf},
year = {2018},
date = {2018-08-16},
urldate = {2018-08-16},
booktitle = {International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Quebec City, Canada},
volume = {51722},
pages = {V01AT02A024},
organization = {American Society of Mechanical Engineers},
abstract = {A central issue in two-sided matching markets such as Cloud-Based Design and Manufacturing (CBDM) where agents interact over a long period of time is the design of optimal matching period during recursive implementation. Existing literature provides mechanisms that satisfy useful properties such as stability in a single matching cycle, but they lack studies on the effect of the period of matching cycle on the optimality. To address this gap, we perform simulation studies on a synthetic CBDM scenario where service seekers arrive as a Poisson process with a fixed number of service providers offering resources. We identify the optimal matching period and assess its robustness using sensitivity studies. Optimality is measured in terms of utility obtained by the agents, the number of matches and fairness of the utility distribution. We show that a matching period equal to the ratio of the number of service providers to the arrival rate of service seekers is optimal.},
keywords = {Cloud-based Design and Manufacturing, Mechanism Design},
pubstate = {published},
tppubtype = {conference}
}
A central issue in two-sided matching markets such as Cloud-Based Design and Manufacturing (CBDM) where agents interact over a long period of time is the design of optimal matching period during recursive implementation. Existing literature provides mechanisms that satisfy useful properties such as stability in a single matching cycle, but they lack studies on the effect of the period of matching cycle on the optimality. To address this gap, we perform simulation studies on a synthetic CBDM scenario where service seekers arrive as a Poisson process with a fixed number of service providers offering resources. We identify the optimal matching period and assess its robustness using sensitivity studies. Optimality is measured in terms of utility obtained by the agents, the number of matches and fairness of the utility distribution. We show that a matching period equal to the ratio of the number of service providers to the arrival rate of service seekers is optimal.
2017
Thekinen, J; Moolchandani, K; Panchal, J; DeLaurentis, D
Modeling Effects of Competition on Airlines’ Route-Selection Decisions Inproceedings
In: 17th AIAA Aviation Technology, Integration, and Operations Conference, Denver, pp. 3598, 2017.
Abstract | BibTeX | Tags: | Links:
@inproceedings{thekinen2017modeling,
title = {Modeling Effects of Competition on Airlines’ Route-Selection Decisions},
author = {Thekinen, J and Moolchandani, K and Panchal, J and DeLaurentis, D},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2017_AIAA_Modeling-Effects-of-Competition-on-Airlines-Route-Selection-Decisions.pdf},
year = {2017},
date = {2017-11-02},
urldate = {2017-11-02},
booktitle = {17th AIAA Aviation Technology, Integration, and Operations Conference, Denver},
pages = {3598},
abstract = {Airlines’ decisions on which routes to operate on depend on a number of factors. This paper discusses the effect of competition on such decisions. Most of the related previous work assumes that the route decisions are independently made based on the local route level characteristics, ignoring broader network properties. In our model, in addition to the effect of local route-level parameters, we include the network level significance of the route. Particularly we study how the entry or exit decisions made by two major alliances on each route are influenced by route-level parameters. Data on past decisions made by the alliances within the US air transportation system (ATS) provide inferences on such parameters. Because decision on whether or not to operate on a route is a discrete choice, our method is based on the discrete games modeling approach. The discrete games model is solved using Markov Chain Monte-Carlo (MCMC) approach to study these decisions. First, we solve for the preference parameters ignoring competition using discrete choice analysis assuming route decisions are independent. The solutions are used as priors in the MCMC technique. We introduce a novel likelihood function that considers the network level significance of routes when multiple Nash Equilibria exist. Results from our model show good agreement with actual data for the year 2014.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Airlines’ decisions on which routes to operate on depend on a number of factors. This paper discusses the effect of competition on such decisions. Most of the related previous work assumes that the route decisions are independently made based on the local route level characteristics, ignoring broader network properties. In our model, in addition to the effect of local route-level parameters, we include the network level significance of the route. Particularly we study how the entry or exit decisions made by two major alliances on each route are influenced by route-level parameters. Data on past decisions made by the alliances within the US air transportation system (ATS) provide inferences on such parameters. Because decision on whether or not to operate on a route is a discrete choice, our method is based on the discrete games modeling approach. The discrete games model is solved using Markov Chain Monte-Carlo (MCMC) approach to study these decisions. First, we solve for the preference parameters ignoring competition using discrete choice analysis assuming route decisions are independent. The solutions are used as priors in the MCMC technique. We introduce a novel likelihood function that considers the network level significance of routes when multiple Nash Equilibria exist. Results from our model show good agreement with actual data for the year 2014.
Thekinen, J; Panchal, J
Resource Allocation in Cloud-based Design and Manufacturing: A Mechanism Design Approach Journal Article
In: Journal of Manufacturing Systems, 43 , pp. 327–338, 2017.
Abstract | BibTeX | Tags: Cloud-based Design and Manufacturing, Mechanism Design | Links:
@article{thekinen2017resource,
title = {Resource Allocation in Cloud-based Design and Manufacturing: A Mechanism Design Approach},
author = {Thekinen, J and Panchal, J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2017_JMS_Resource-Allocation-in-Cloud-based-Design-and-Manufacturing-A-Mechanism-Design-Approach.pdf},
doi = {10.1016/j.jmsy.2016.08.005},
year = {2017},
date = {2017-09-01},
urldate = {2017-09-01},
journal = {Journal of Manufacturing Systems},
volume = {43},
pages = {327--338},
publisher = {Elsevier},
abstract = {The focus of this paper is on matching service seekers and service providers, such as designers and machine owners, in Cloud-Based Design and Manufacturing (CBDM). In such decentralized scenarios the objectives and preferences of service seekers are different from those of service providers. Current resource configuration methods are unsuitable because they optimize the objectives of only one type of participants -- either service seekers or service providers. Existing marketplaces based on first-come-first-serve (FCFS) approach are inefficient because they may not result in optimal matches. To address these limitations there is a need for mechanisms that result in optimal matching considering the private preferences of all the agents. In this paper, we formulate the resource allocation problem as a bipartite matching problem. Four bipartite matching mechanisms, namely, Deferred Acceptance (DA), Top Trading Cycle (TTC), Munkres, and FCFS are analyzed with respect to desired properties of the mechanisms such as individual rationality, stability, strategy proofness, consistency, monotonicity and Pareto efficiency. Further, the performance of these mechanisms is evaluated under different levels of resource availability through simulation studies. The appropriateness of matching mechanisms for different scenarios in CBDM such as fully decentralized, partially decentralized and totally monopolistic are assessed. Based on the analysis, we conclude that DA is the best mechanism for totally decentralized scenario, TTC is most appropriate when cloud-based resources are used in an organizational scenario, and Munkres is the best mechanism when all resources are owned by a single agent.},
keywords = {Cloud-based Design and Manufacturing, Mechanism Design},
pubstate = {published},
tppubtype = {article}
}
The focus of this paper is on matching service seekers and service providers, such as designers and machine owners, in Cloud-Based Design and Manufacturing (CBDM). In such decentralized scenarios the objectives and preferences of service seekers are different from those of service providers. Current resource configuration methods are unsuitable because they optimize the objectives of only one type of participants -- either service seekers or service providers. Existing marketplaces based on first-come-first-serve (FCFS) approach are inefficient because they may not result in optimal matches. To address these limitations there is a need for mechanisms that result in optimal matching considering the private preferences of all the agents. In this paper, we formulate the resource allocation problem as a bipartite matching problem. Four bipartite matching mechanisms, namely, Deferred Acceptance (DA), Top Trading Cycle (TTC), Munkres, and FCFS are analyzed with respect to desired properties of the mechanisms such as individual rationality, stability, strategy proofness, consistency, monotonicity and Pareto efficiency. Further, the performance of these mechanisms is evaluated under different levels of resource availability through simulation studies. The appropriateness of matching mechanisms for different scenarios in CBDM such as fully decentralized, partially decentralized and totally monopolistic are assessed. Based on the analysis, we conclude that DA is the best mechanism for totally decentralized scenario, TTC is most appropriate when cloud-based resources are used in an organizational scenario, and Munkres is the best mechanism when all resources are owned by a single agent.
Datta, N; Thekinen, J
Transient Point Load Induced Response of Kirchhoff’s Plate with Translationally Constrained Edges: Aircraft Landing on Floating Airports Journal Article
In: Marine Systems & Ocean Technology, 12 (4), pp. 252–261, 2017.
Abstract | BibTeX | Tags: | Links:
@article{nokey,
title = {Transient Point Load Induced Response of Kirchhoff’s Plate with Translationally Constrained Edges: Aircraft Landing on Floating Airports},
author = {Datta, N and Thekinen, J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2017_MSOT_Transient-point-load-induced-response-of-Kirchhoffs-plate-with-translationally-constrained-edges-aircraft-landing-on-floating-airports.pdf},
doi = {10.1007/s40868-017-0038-y},
year = {2017},
date = {2017-08-16},
urldate = {2017-08-16},
journal = {Marine Systems & Ocean Technology},
volume = {12},
number = {4},
pages = {252--261},
abstract = {Dynamic analysis of thin rectangular elastically supported plates to transient loads is presented. A floating airport is modeled as a horizontal Kirchhoff’s plate, which is elastically supported at the ends, and is subjected to the impact of aircrafts landing and deceleration over its length. This sets the free–free–free–free plate into high-frequency vibration, causing flexural stress waves to travel over the plate. First, the beam natural frequencies and modeshapes in either direction are generated with these complexities. The eigenvalue analysis of the governing differential equation is done, using the weighted summation of the product of the beam modes. The radiation pressure on the bottom side of the plate is included to reduce the frequencies by the added-mass effect. The plate is then subjected to decelerating shock loads. The vibratory response is analyzed by the computationally efficient normal mode analysis. The amplification factor versus the taxiing time of the moving load is generated. This gives insights into the maximum stress encountered under the transient load, as function of taxiing time and support.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Dynamic analysis of thin rectangular elastically supported plates to transient loads is presented. A floating airport is modeled as a horizontal Kirchhoff’s plate, which is elastically supported at the ends, and is subjected to the impact of aircrafts landing and deceleration over its length. This sets the free–free–free–free plate into high-frequency vibration, causing flexural stress waves to travel over the plate. First, the beam natural frequencies and modeshapes in either direction are generated with these complexities. The eigenvalue analysis of the governing differential equation is done, using the weighted summation of the product of the beam modes. The radiation pressure on the bottom side of the plate is included to reduce the frequencies by the added-mass effect. The plate is then subjected to decelerating shock loads. The vibratory response is analyzed by the computationally efficient normal mode analysis. The amplification factor versus the taxiing time of the moving load is generated. This gives insights into the maximum stress encountered under the transient load, as function of taxiing time and support.
2016
Mandhan, N; Thekinen, J; Lo, A; Panchal, J
Matching Designers and 3D Printing Service Providers Using Gale-Shapley Algorithm Conference
Proceedings of the Eleventh International Symposium on Tools and Methods of Competitive Engineering, Aix-en-Provence, France, 2016.
Abstract | BibTeX | Tags: Cloud-based Design and Manufacturing, Mechanism Design | Links:
@conference{mandhan2016matching,
title = {Matching Designers and 3D Printing Service Providers Using Gale-Shapley Algorithm},
author = {Mandhan, N and Thekinen, J and Lo, A and Panchal, J },
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2016_TMCE_MATCHING-DESIGNERS-AND-3D-PRINTING-SERVICE-PROVIDERS-USING-GALE-SHAPLEY-ALGORITHM.pdf},
year = {2016},
date = {2016-07-01},
urldate = {2016-07-01},
booktitle = {Proceedings of the Eleventh International Symposium on Tools and Methods of Competitive Engineering, Aix-en-Provence, France},
abstract = {With the increasing availability of mid-to-low price 3D printers, it is increasingly possible for individuals and medium-sized enterprises to own such machines. However, such owners rarely utilize the full capacity of these machines. The excess capacity can be made available to interested designers who would like to get their designs printed, but do not own the machines. This has resulted in an emergence of online portals, where machine owners can register and advertise their printing resources, and designers can avail these resources to choose the machine that best suits their design. Presently a first-come-first-serve approach is used to match the designers with machine owners. The primary limitations of this approach are that (a) the capacity of the machines is highly under-utilized and (b) the matching is based solely on the designers’ preferences while ignoring the machine owners’ preferences. To address these limitations, we propose the use of Gale-Shapley matching algorithm after applying the utility theory to obtain the designer and manufacturer preferences for one another. The use of Gale-Shapley matching algorithm is evaluated and compared with the first-come-first-serve approach. The results of the study indicate that the approach based on Gale-Shapley matching improves the total social welfare over the present first-come-first-serve approach. While this method is slightly biased in favor of either the designers or the machine owners, given the limitations of the algorithm, both sides have improved utility and get matched to a design or machine high in their preference ordering.},
keywords = {Cloud-based Design and Manufacturing, Mechanism Design},
pubstate = {published},
tppubtype = {conference}
}
With the increasing availability of mid-to-low price 3D printers, it is increasingly possible for individuals and medium-sized enterprises to own such machines. However, such owners rarely utilize the full capacity of these machines. The excess capacity can be made available to interested designers who would like to get their designs printed, but do not own the machines. This has resulted in an emergence of online portals, where machine owners can register and advertise their printing resources, and designers can avail these resources to choose the machine that best suits their design. Presently a first-come-first-serve approach is used to match the designers with machine owners. The primary limitations of this approach are that (a) the capacity of the machines is highly under-utilized and (b) the matching is based solely on the designers’ preferences while ignoring the machine owners’ preferences. To address these limitations, we propose the use of Gale-Shapley matching algorithm after applying the utility theory to obtain the designer and manufacturer preferences for one another. The use of Gale-Shapley matching algorithm is evaluated and compared with the first-come-first-serve approach. The results of the study indicate that the approach based on Gale-Shapley matching improves the total social welfare over the present first-come-first-serve approach. While this method is slightly biased in favor of either the designers or the machine owners, given the limitations of the algorithm, both sides have improved utility and get matched to a design or machine high in their preference ordering.
Moolchandani, K; Sha, Z; Maheshwari, A; Thekinen, J; Davendralingam, N; Panchal, J; DeLaurentis, D
Towards A Hierarchical Decision-Centric Modeling Framework for Air Transportation Systems Conference
16th AIAA Aviation Technology, Integration, and Operations Conference, Washington, D.C., 2016.
Abstract | BibTeX | Tags: Complex Networked Systems | Links:
@conference{moolchandani2016hierarchical,
title = {Towards A Hierarchical Decision-Centric Modeling Framework for Air Transportation Systems},
author = {Moolchandani, K and Sha, Z and Maheshwari, A and Thekinen, J and Davendralingam, N and Panchal, J and DeLaurentis, D},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2016_AIAA_Towards-A-Hierarchical-Decision-Centric-Modeling-Framework-for-Air-Transportation-Systems.pdf},
year = {2016},
date = {2016-06-04},
booktitle = {16th AIAA Aviation Technology, Integration, and Operations Conference, Washington, D.C.},
pages = {3154},
abstract = {This work is part of ongoing research towards the development of a multi-level framework that is envisioned to provide the ability to holistically study the future evolution of the ATS as a result of decisions made by relevant stakeholders. In prior work, the authors have developed a discrete choice model to mimic the airlines route-planning decisions. In this paper, we present a passengers choice model, which forms the post-airline decision phase in the resulting bi-level decision-making framework. The passengers in our model make decisions on the type of itineraries being offers by the airlines, including both the choice of number of layovers to make and where to make those layovers. Specifically, we show separate multiple linear regression models for passengers choices on three different types of itineraries non-stop, one-stop, and two-or-more-stops. We present results of our model using data from the Bureau of Transportation Statistics.},
keywords = {Complex Networked Systems},
pubstate = {published},
tppubtype = {conference}
}
This work is part of ongoing research towards the development of a multi-level framework that is envisioned to provide the ability to holistically study the future evolution of the ATS as a result of decisions made by relevant stakeholders. In prior work, the authors have developed a discrete choice model to mimic the airlines route-planning decisions. In this paper, we present a passengers choice model, which forms the post-airline decision phase in the resulting bi-level decision-making framework. The passengers in our model make decisions on the type of itineraries being offers by the airlines, including both the choice of number of layovers to make and where to make those layovers. Specifically, we show separate multiple linear regression models for passengers choices on three different types of itineraries non-stop, one-stop, and two-or-more-stops. We present results of our model using data from the Bureau of Transportation Statistics.
Chaudhari, A; Thekinen, J; Panchal, J
Using Contests for Engineering Systems Design: A Study of Auctions and Fixed-prize Tournaments Conference
DS 84: Proceedings of the DESIGN 2016 14th International Design Conference, Dubrovnik - Croatia, 2016.
BibTeX | Tags: | Links:
@conference{chaudhari2016using,
title = {Using Contests for Engineering Systems Design: A Study of Auctions and Fixed-prize Tournaments},
author = {Chaudhari, A and Thekinen, J and Panchal, J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2015_Sha_Modeling-Airline-Decisions-on-Route-Planning-Using-Discrete-Choice-Models.pdf},
year = {2016},
date = {2016-05-16},
urldate = {2021-05-16},
booktitle = {DS 84: Proceedings of the DESIGN 2016 14th International Design Conference, Dubrovnik - Croatia},
pages = {947--956},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Datta, N; Thekinen, J
A Rayleigh-Ritz based Approach to Characterize the Vertical Vibration of Non-uniform Hull Girder Journal Article
In: Ocean Engineering, 125 , pp. 113–123, 2016.
Abstract | BibTeX | Tags: | Links:
@article{datta2016rayleigh,
title = {A Rayleigh-Ritz based Approach to Characterize the Vertical Vibration of Non-uniform Hull Girder},
author = {Datta, N and Thekinen, J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2016_OE_A-Rayleigh–Ritz-based-approach-to-characterize-the-vertical-vibration-of-non-uniform-hull-girder.pdf},
doi = {10.1016/j.oceaneng.2016.07.046},
year = {2016},
date = {2016-02-02},
journal = {Ocean Engineering},
volume = {125},
pages = {113--123},
abstract = {Previous attempts to solve for vibration of non-uniform hull girder have used Finite Element Analysis (FEA). This work utilizes the Rayleigh–Ritz (R–R) method to analyze the vertical vibration of a nonprismatic mathematical hull, with arbitrary longitudinal distribution of sectional properties. It is shown that (a) the R-R method provides reasonably accurate results for the actual natural frequency; and (b) the R–R method offers significant computational advantages over FEA. This computational supremacy can be exploited in the initial design stages when several designs are to be iteratively tested for its structural characteristics. The natural frequencies and modeshapes are obtained by the Rayleigh–Ritz method. The non-uniform beam modeshape is a weighted series sum of the (closed-form) uniform beam modeshapes. Only a few uniform beam modes are necessary to generate the non-uniform beam modeshape and a convergent hull girder frequency. Thus, the method is very effective in the low-frequency domain like ship-structure. The proposed method is compared with FEA for two illustrative structures : (a) a containership and (b) a tanker; and also with several hulls from established literature. Modal convergence studies have also been included. The distortions of the non-uniform modeshapes have been studied in the light of the loading conditions of the hull},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Previous attempts to solve for vibration of non-uniform hull girder have used Finite Element Analysis (FEA). This work utilizes the Rayleigh–Ritz (R–R) method to analyze the vertical vibration of a nonprismatic mathematical hull, with arbitrary longitudinal distribution of sectional properties. It is shown that (a) the R-R method provides reasonably accurate results for the actual natural frequency; and (b) the R–R method offers significant computational advantages over FEA. This computational supremacy can be exploited in the initial design stages when several designs are to be iteratively tested for its structural characteristics. The natural frequencies and modeshapes are obtained by the Rayleigh–Ritz method. The non-uniform beam modeshape is a weighted series sum of the (closed-form) uniform beam modeshapes. Only a few uniform beam modes are necessary to generate the non-uniform beam modeshape and a convergent hull girder frequency. Thus, the method is very effective in the low-frequency domain like ship-structure. The proposed method is compared with FEA for two illustrative structures : (a) a containership and (b) a tanker; and also with several hulls from established literature. Modal convergence studies have also been included. The distortions of the non-uniform modeshapes have been studied in the light of the loading conditions of the hull
2015
Sha, Z; Moolchandani, K; Maheshwari, A; Thekinen, J; Panchal, J; DeLaurentis, D
Modeling Airline Decisions on Route Planning Using Discrete Choice Models Conference
15th AIAA Aviation Technology, Integration, and Operations Conference, Dallas - Texas, 2015.
Abstract | BibTeX | Tags: Complex Networked Systems | Links:
@conference{sha2015modeling,
title = {Modeling Airline Decisions on Route Planning Using Discrete Choice Models},
author = {Sha, Z and Moolchandani, K and Maheshwari, A and Thekinen, J and Panchal, J and DeLaurentis, D},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2015_Sha_Modeling-Airline-Decisions-on-Route-Planning-Using-Discrete-Choice-Models.pdf},
year = {2015},
date = {2015-06-22},
urldate = {2015-06-22},
booktitle = {15th AIAA Aviation Technology, Integration, and Operations Conference, Dallas - Texas},
pages = {2438},
abstract = {We propose a model for the airlines’ decisions on route planning, i.e., the decision on selecting which route to add and delete, using discrete choice random-utility theory. The central hypothesis is that a discrete choice model can effectively model the airlines’ decisions on route selection , and thereby help model the evolution of the air transportation network. We first model the airlines’ utility function as a linear function of decision variables with interaction effects. The decision of route selection is then modeled using a binary choice model derived from the utility function. The preferences for each variable in the utility function are estimated using historical datasets. Advantages of this approach include the ability to use statistical techniques to quantitatively construct decision models as well as to account for the uncertainty in unobserved attributes of the decision model. The proposed model helps predict the airlines’ decisions on routes addition and deletion which affect the network topology of air transportation and its future evolution. This capability can be beneficial to other stakeholders, such as Federal Aviation Administration, who may need to make their decisions in response to those made by the airlines, but do not have access to the airlines’ true decision models.},
keywords = {Complex Networked Systems},
pubstate = {published},
tppubtype = {conference}
}
We propose a model for the airlines’ decisions on route planning, i.e., the decision on selecting which route to add and delete, using discrete choice random-utility theory. The central hypothesis is that a discrete choice model can effectively model the airlines’ decisions on route selection , and thereby help model the evolution of the air transportation network. We first model the airlines’ utility function as a linear function of decision variables with interaction effects. The decision of route selection is then modeled using a binary choice model derived from the utility function. The preferences for each variable in the utility function are estimated using historical datasets. Advantages of this approach include the ability to use statistical techniques to quantitatively construct decision models as well as to account for the uncertainty in unobserved attributes of the decision model. The proposed model helps predict the airlines’ decisions on routes addition and deletion which affect the network topology of air transportation and its future evolution. This capability can be beneficial to other stakeholders, such as Federal Aviation Administration, who may need to make their decisions in response to those made by the airlines, but do not have access to the airlines’ true decision models.
2013
Datta, N; Thekinen, J
Wet Vibration of Axially Loaded Elastically Supported Plates to Moving Loads: Aircraft Landing on Floating Airports Conference
International Conference on Offshore Mechanics and Arctic Engineering, Nantes - France, 55317 , American Society of Mechanical Engineers 2013.
Abstract | BibTeX | Tags: | Links:
@conference{datta2013wet,
title = {Wet Vibration of Axially Loaded Elastically Supported Plates to Moving Loads: Aircraft Landing on Floating Airports},
author = {Datta, N and Thekinen, J},
url = {https://josephdthekinen.com/wp-content/uploads/2021/11/2013_OMAE_Wet-vibration-of-axially-loaded-elastically-supported-plates-to-moving-loads-aircraft-landing-on-floating-airports.pdf},
year = {2013},
date = {2013-06-09},
booktitle = {International Conference on Offshore Mechanics and Arctic Engineering, Nantes - France},
volume = {55317},
pages = {V001T01A026},
organization = {American Society of Mechanical Engineers},
abstract = {Dynamic analysis of thin rectangular elastically supported stiffened plates with axial loads is presented. A floating airport is modeled as a horizontal Kirchhoff‟s plate, which is elastically supported at the ends; and is subjected to the impact of aircrafts landing and deceleration over its length. This sets the free-free-free-free plate into high-frequency vibration, causing flexural stress waves to travel over the plate. First, the beam natural frequencies and modeshapes in either direction are generated with these complexities. The Eigen value analysis of the governing differential equation is done, using the weighted summation of the product of the beam modes. The accuracy of the frequencies is compared with those from FEA studies. The radiation pressure on the bottom side of the plate is included to reduce the frequencies by the addedmass effect. The plate is then subjected to decelerating shock loads. The vibratory response is analyzed by the computationally efficient normal mode analysis. The amplification factor vs. the taxiing time of the moving load is generated.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Dynamic analysis of thin rectangular elastically supported stiffened plates with axial loads is presented. A floating airport is modeled as a horizontal Kirchhoff‟s plate, which is elastically supported at the ends; and is subjected to the impact of aircrafts landing and deceleration over its length. This sets the free-free-free-free plate into high-frequency vibration, causing flexural stress waves to travel over the plate. First, the beam natural frequencies and modeshapes in either direction are generated with these complexities. The Eigen value analysis of the governing differential equation is done, using the weighted summation of the product of the beam modes. The accuracy of the frequencies is compared with those from FEA studies. The radiation pressure on the bottom side of the plate is included to reduce the frequencies by the addedmass effect. The plate is then subjected to decelerating shock loads. The vibratory response is analyzed by the computationally efficient normal mode analysis. The amplification factor vs. the taxiing time of the moving load is generated.
2012
Datta, N; Thekinen, J
Higher-order Dry and Wet Natural Frequencies and Modeshapes of Rectangular Kirchhoff’s Plate Vibration Conference
Third Asian Conference on Mechanics of Functional Materials and Structures, IIT Delhi, 2012.
BibTeX | Tags:
@conference{nokey,
title = {Higher-order Dry and Wet Natural Frequencies and Modeshapes of Rectangular Kirchhoff’s Plate Vibration},
author = {Datta, N and Thekinen, J},
year = {2012},
date = {2012-12-01},
booktitle = {Third Asian Conference on Mechanics of Functional Materials and Structures, IIT Delhi},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Thekinen, J; Datta, N
Response Spectrum of Non-uniform Mathematical Hull Girder Springing to Deep Water Random Seas with Forward Speeds Conference
8th International Conference in Marine Technology, Kuala Terengganu - Malaysia, 2012.
BibTeX | Tags:
@conference{nokey,
title = {Response Spectrum of Non-uniform Mathematical Hull Girder Springing to Deep Water Random Seas with Forward Speeds},
author = {Thekinen, J and Datta, N },
year = {2012},
date = {2012-12-01},
booktitle = {8th International Conference in Marine Technology, Kuala Terengganu - Malaysia},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}