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You searched for +publisher:"University of Texas – Austin" +contributor:("Mok, Aloysius K"). Showing records 1 – 3 of 3 total matches.

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University of Texas – Austin

1. -0657-6898. Link formation in mobile and economic networks : model and empirical analysis.

Degree: PhD, Computer Science, 2015, University of Texas – Austin

In this dissertation, we study three link formation problems in mobile and economic networks: (i) company matching for mergers and acquisitions (M&A) network in the high-technology (high-tech) industry, (ii) mobile application (app) matching for cross promotion network in mobile app markets, and (iii) online friendship formation in mobile social networks. Each problem can be modeled as link formation problem in a graph, where nodes represent independent entities (e.g., companies, apps, users) and edges represent interactions (e.g., transactions, promotions, friendships) among the nodes. First, we propose a new data-analytic approach to measure firms' dyadic business proximity to analyze M&A network in the high-tech industry. Specifically, our method analyzes the unstructured texts that describe firms' businesses using latent Dirichlet allocation (LDA) topic modeling, and constructs a novel business proximity measure based on the output. Using CrunchBase data including 24,382 high-tech companies and 1,689 M&A transactions, we empirically validate our business proximity measure in the context of industry intelligence and show the measure's effectiveness in an application of M&A network analysis. Based on the research, we build a cloud-based information system to facilitate competitive intelligence on the high-tech industry. Second, we analyze mobile app matching for cross promotion network in mobile app markets. Cross promotion (CP) is a new app promotion framework, in which a mobile app is promoted to the users of another app. Using IGAWorks data covering 1,011 CP campaigns, 325 apps, and 301,183 users, we evaluate the effectiveness of CP campaigns in comparison with existing ad channels such as mobile display ads. While CP campaigns, on average, are still suboptimal as compared with display ads, we find evidence that a careful matching of mobile apps can significantly improve the effectiveness of CP campaigns. Our empirical results show that app similarity, measured by LDA from apps' text descriptions, is a significant factor that increases the user engagement in CP campaigns. With this observation, we propose an app matching mechanism for the CP network to improve the ad effectiveness. Third, we study friendship network formation in a location-based social network. We build a structural model of social link creation that incorporates individual characteristics and pairwise user similarities. Specifically, we define four user proximity measures from biography, geography, mobility, and short messages (i.e., tweets). To construct proximity from unstructured text information, we build LDA topic models of user biography texts and tweets. Using Gowalla data with 385,306 users, three million locations, and 35 million check-in records, we empirically estimate the structural model to find evidence on the homophily effect in network formation. Advisors/Committee Members: Whinston, Andrew B. (advisor), Han, Sukjin (committee member), Lifschitz, Vladimir (committee member), Mok, Aloysius K (committee member), Qiu, Lili (committee member).

Subjects/Keywords: Link formation; Mobile ecosystem; Economic networks; Topic model; Econometric model; Big Data; M&A; Cross promotion; Social network

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

-0657-6898. (2015). Link formation in mobile and economic networks : model and empirical analysis. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/46762

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Chicago Manual of Style (16th Edition):

-0657-6898. “Link formation in mobile and economic networks : model and empirical analysis.” 2015. Doctoral Dissertation, University of Texas – Austin. Accessed September 18, 2020. http://hdl.handle.net/2152/46762.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

MLA Handbook (7th Edition):

-0657-6898. “Link formation in mobile and economic networks : model and empirical analysis.” 2015. Web. 18 Sep 2020.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-0657-6898. Link formation in mobile and economic networks : model and empirical analysis. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2015. [cited 2020 Sep 18]. Available from: http://hdl.handle.net/2152/46762.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Council of Science Editors:

-0657-6898. Link formation in mobile and economic networks : model and empirical analysis. [Doctoral Dissertation]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/46762

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete


University of Texas – Austin

2. -0973-5180. Performance and manufacturing considerations for series elastic actuators.

Degree: PhD, Mechanical Engineering, 2017, University of Texas – Austin

Robots are becoming an integral part of our lives. We are already physically connected with them through many robotic applications such as exoskeletons in military, orthosis devices in health care, collaborative robots in industry, etc. While the integration of robots improves the quality of human life, it still poses a safety concern during the physical human-robot interaction. Series Elastic Actuators (SEAs) play an important role in improving the safety of human-robot interaction and collaboration. Considering the fast expansion of robotic applications in our lives and the safety benefits of SEAs, it is conceivable that SEAs are going to play an important role in robotic applications in every aspect of human life. This dissertation focuses on reducing the cost, simplifying the use and improving the performance of SEAs. The first research focus in this dissertation is to reduce the cost of SEAs. Robots are successful in reducing production and service costs when used but the capital cost of robot installations are very high. As robotics research shifts to safe robotic applications, reducing the cost of SEAs will greatly help to deploy this technology in more robotic applications and to increase their accessibility to a broader range of researchers and educators. With this motivation, I present a case study on reducing the cost of a SEA while maintaining high force and position control performance and industrial grade service life. The second research focus in this dissertation is to simplify the laborious gain selection process of the cascaded controllers of SEAs. In order to simplify the gain selection process of the impedance controllers of SEAs, an optimal feedback gain selection methodology was developed. Using this method, the feedback gains of the cascaded PD-type impedance controllers of SEAs can easily be calibrated. The developed method allows the users to find the highest feedback gains for a desired phase-margin. Beyond the low-cost realization and simple controller tuning of SEAs, performance improvements on SEAs are possible utilizing the series elasticity in these actuators. As the third research focus in this dissertation, a sequential convex optimization-based motion planning technique is developed in order to improve the joint velocity capabilities of SEAs with nonlinearities. By using this method, higher joint velocities, that are not achievable with the rigid counterparts of SEAs can be achieved Advisors/Committee Members: Sentis, Luis (advisor), Fernandez, Benito R (committee member), Chen, Dongmei (committee member), Barr, Ronald (committee member), Mok, Aloysius K (committee member).

Subjects/Keywords: Series elastic actuator; Low-cost; Industrial grade; Impedance control; Gain selection; Motion planning

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

-0973-5180. (2017). Performance and manufacturing considerations for series elastic actuators. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://dx.doi.org/10.26153/tsw/2811

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Chicago Manual of Style (16th Edition):

-0973-5180. “Performance and manufacturing considerations for series elastic actuators.” 2017. Doctoral Dissertation, University of Texas – Austin. Accessed September 18, 2020. http://dx.doi.org/10.26153/tsw/2811.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

MLA Handbook (7th Edition):

-0973-5180. “Performance and manufacturing considerations for series elastic actuators.” 2017. Web. 18 Sep 2020.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-0973-5180. Performance and manufacturing considerations for series elastic actuators. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2017. [cited 2020 Sep 18]. Available from: http://dx.doi.org/10.26153/tsw/2811.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Council of Science Editors:

-0973-5180. Performance and manufacturing considerations for series elastic actuators. [Doctoral Dissertation]. University of Texas – Austin; 2017. Available from: http://dx.doi.org/10.26153/tsw/2811

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete


University of Texas – Austin

3. Reaz, Rezwana. Theory and practice of firewall outsourcing.

Degree: PhD, Computer Science, 2020, University of Texas – Austin

A firewall system is a packet filter that is placed at the entry point of an enterprise network in the Internet. Packets that attempt to enter the enterprise network through this entry point are examined, one by one, against the rules of some underlying firewall F of the firewall system. Each rule in F has a decision which is either “accept” or “reject”. For any incoming packet p, the firewall system identifies the first rule (in the sequence of rules in F) that matches p. If the decision of this rule is “accept”, then the firewall system forwards p to the enterprise network. Otherwise the decision of this rule is “reject” and packet p is discarded and prevented from entering the network. Each firewall system consists of two units: a rule matching unit and a decision unit. Both units are usually executed in the firewall system. To simplify the task of managing the firewall system, we identify a special class of firewall systems, called the outsourced system, where the rule matching unit is executed in a public cloud. Unfortunately, public clouds are usually unreliable and execution of the rule matching unit in a public cloud can be vulnerable to two types of attacks: verifiability attacks and privacy attacks. The main objective of this dissertation is to discuss how to execute the rule matching unit of an outsourced system in a public cloud such that verifiability and privacy attacks are prevented from occurring. The main contribution of this dissertation is three-fold. First, we discuss how to design outsourced firewall system such that execution of the designed system in the public clouds prevents the occurrence of verifiability and privacy attacks. The resulting system, called the private system, make use of two public clouds. We show that this private system prevents verifiability and privacy attacks under the assumption that the two public clouds used in this system are both “sensible” and “non-colluding”. Second, we identify a special class of firewalls, called the partially specified firewall, where a firewall is called partially specified when the decisions of some of the rules in the firewall are not specified as “accept” or “reject”. We show that for every partially specified firewall PF, there is a (fully specified) firewall F such that PF and F are equivalent. We discuss how to design an outsourced system whose underlying firewall is a partially specified firewall PF such that the designed system prevents both verifiability and privacy attacks. We achieve this outsourced system by obtaining an equivalent firewall F from PF and designing a private system for F. Third, we present a generalization of firewalls called firewall expressions. A firewall expression is specified using one or more component firewalls and three firewall operators: “not”, “and”, and “or”. For example, the firewall expression (G and H) consists of two component firewalls G and H and one firewall operator “and”. This firewall expression accepts a packet p iff both firewalls G and H accept p. For any underlying firewall expression FE,… Advisors/Committee Members: Gouda, Mohamed G., 1947- (advisor), Mok, Aloysius K (committee member), Qiu, Lili (committee member), Acharya, Hrishikesh B (committee member).

Subjects/Keywords: Firewalls; Firewall systems; Outsourcing; Outsourced systems; Public cloud; Cloud computing; Verifiability; Privacy; Network management

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Reaz, R. (2020). Theory and practice of firewall outsourcing. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://dx.doi.org/10.26153/tsw/8361

Chicago Manual of Style (16th Edition):

Reaz, Rezwana. “Theory and practice of firewall outsourcing.” 2020. Doctoral Dissertation, University of Texas – Austin. Accessed September 18, 2020. http://dx.doi.org/10.26153/tsw/8361.

MLA Handbook (7th Edition):

Reaz, Rezwana. “Theory and practice of firewall outsourcing.” 2020. Web. 18 Sep 2020.

Vancouver:

Reaz R. Theory and practice of firewall outsourcing. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2020. [cited 2020 Sep 18]. Available from: http://dx.doi.org/10.26153/tsw/8361.

Council of Science Editors:

Reaz R. Theory and practice of firewall outsourcing. [Doctoral Dissertation]. University of Texas – Austin; 2020. Available from: http://dx.doi.org/10.26153/tsw/8361

.