Institute for Software Research Copyright (c) 2013 Carnegie Mellon University All rights reserved. http://repository.cmu.edu/isr Recent documents in Institute for Software Research en-us Wed, 12 Jun 2013 13:50:24 PDT 3600 Detailed comparison of America's Army game and Unit of Action experiments http://repository.cmu.edu/isr/863 http://repository.cmu.edu/isr/863 Wed, 23 May 2012 19:24:24 PDT Abstract: "America's Army game and Unit of Action experiments are simulations of military units. America's Army is a simulation of a squad level military organization, and the Unit of Action experiments simulate the brigade/battalion level command and control structure. Studies of both these domains reveal that configuring and organizing a unit is important in enhancing its performance. Thus, we may argue that there is a fundamental similarity between the game and the experiment. In this paper, we compare the two simulation analyses in terms of their initial features, results, and recommendations. The comparison of the initial features suggests that both domains use similar explanatory variables, and the comparison of the results shows that the findings of these domains also correspond in many ways. Finally, we investigate different ways of capturing implications in both domains, and based on that, discuss future research issues for the Unit of Action experiments such as developing an ideal communication network or policy by adopting a research method used in the America s Army analysis."

]]> Mike Schneider et al. Counter-forensic privacy tools : a forensic evaluation http://repository.cmu.edu/isr/862 http://repository.cmu.edu/isr/862 Wed, 23 May 2012 19:23:58 PDT Abstract: "Modern operating systems and the applications that run on them generate copious amounts of data about their users' activity. Users are increasingly aware of their privacy exposure from these records and from digital artifacts that linger after files are "deleted" on computers they use. Efforts to redress this privacy exposure have spawned a range of counter-forensic privacy tools - software designed to irretrievably eliminate records of computer system usage and other sensitive data. In this paper, we use forensic tools and techniques to evaluate the effectiveness of six counter-forensic software packages. The results highlight some significant shortfalls in the implementation and approach of these tools, leading to privacy concerns about the exposure of sensitive data. The findings also raise questions about the level of privacy protection that is realistic to expect from these tools, and others that take a similar approach."

]]> Matthew Geiger et al. Towards an information theoretic framework for location-based data linkage http://repository.cmu.edu/isr/861 http://repository.cmu.edu/isr/861 Wed, 23 May 2012 19:23:34 PDT Abstract: "A long-standing challenge for data management is the ability to correctly relate information corresponding to the same entity distributed across databases. Traditional research into record linkage has concentrated on string comparator metrics for records with common, or relatable, attributes. However, spatially distributed data are often devoid of such crucial information for database schema integration. Rather than directly relate schemas, spatially distributed data can be related through location-based linkage algorithms, which link patterns in location-specific attributes (e.g. visit). In this paper we focus on two fundamental algorithms for location-based linkage and we investigate how different distributions of how entities visit locations influence linkage performance. We begin by studying algorithm accuracy for linking real-world data. We then outline a theoretical framework rooted in information theory that allows us to provide insight into observed phenomena. Our framework also provides a useful basis for studying the performance of location-based linkage algorithms: we analyze two opposing cases where location visit patterns arise from uniform and power distributions of entities to locations. We carry out our investigations under both the assumption of complete and incomplete information. Our findings suggest that low skew distributions are more easily linked when complete information is known. In contrast, when information is incomplete high skew distributions lead to higher linkage rates."

]]> Bradley Malin et al. Pricing for customers with probabilistic valuations as a continuous knapsack problem http://repository.cmu.edu/isr/860 http://repository.cmu.edu/isr/860 Wed, 23 May 2012 19:23:10 PDT Abstract: "In this paper, we examine the problem of choosing discriminatory prices for customers with probabilistic valuations and a seller with indistinguishable copies of a good. We show that under certain assumptions this problem can be reduced to the continuous knapsack problem (CKP). We present a new fast [epsilon]-optimal algorithm for solving CKP instances with asymmetric concave reward functions. We also show that our algorithm can be extended beyond the CKP setting to handle pricing problems with overlapping goods (e.g. goods with common components or common resource requirements), rather than indistinguishable goods. We provide a framework for learning distributions over customer valuations from historical data that are accurate and compatible with our CKP algorithm, and we validate our techniques with experiments on pricing instances derived from the Trading Agent Competition in Supply Chain Management (TAC SCM). Our results confirm that our algorithm converges to an [epsilon]-optimal solution more quickly in practice than an adaptation of a previously proposed greedy heuristic."

]]> Michael Benisch et al. Examining DCSP coordination tradeoffs http://repository.cmu.edu/isr/859 http://repository.cmu.edu/isr/859 Wed, 23 May 2012 19:22:46 PDT Abstract: "Distributed Constraint Satisfaction Problems (DCSPs) provide a model to capture a broad range of cooperative multi-agent problem solving settings. Researchers have generally proposed two different sets of approaches for solving DCSPs, backtracking based approaches, such as Asynchronous Backtracking (ABT), and mediation based approaches, such as Asynchronous Partial Overlay (APO). These sets of approaches differ in the levels of coordination employed during conflict resolution. While the computational and communication complexity of the backtracking based approaches is well understood, the tradeoffs in complexity involved in moving toward mediation based approaches are not. In this paper we comprehensively reexamine the space of mediation based approaches for DCSP and fill gaps in existing frameworks with new strategies. We present different mediation session selection rules, including a rule that favors smaller mediation sessions, and different mediation strategies, including a decentralized hybrid strategy based on ABT. We present empirical results on solvable 3-coloring and random binary DCSP problems, that accurately capture the computational and communication tradeoffs between ABT and various mediation based approaches. Our results confirm that under some circumstances the newly presented strategies dominate previously proposed techniques."

]]> Michael Benisch et al. Identifying categories of end users based on the abstractions that they create http://repository.cmu.edu/isr/858 http://repository.cmu.edu/isr/858 Wed, 23 May 2012 19:22:22 PDT Abstract: "Software created by end users often lacks key quality attributes that professional programmers try to ensure through the use of abstraction. Yet to date, large-scale studies of end users have not examined end user software usage at a level which is sufficiently fine-grained to determine the extent to which they create abstractions. To address this, we deployed an online survey to Information Week subscribers to ask about not only software usage but also feature usage related to abstraction creation. Most respondents did create abstractions. Moreover, through factor analysis, we found that features fell into three clusters -- when users had a propensity to use one feature, then they also had a propensity to use other features in the same cluster. These clusters corresponded to macro features, linked data structure features, and imperative features. For each of the three factors, we created a scale and used it to categorize users into two bins -- those with a high propensity to use features associated with that scale, and those with a low propensity. Compared to users with a low propensity to use imperative features, users with a high propensity to use imperative features were more likely to report testing and documenting. Propensity to use linked structure features was less strongly related to these practices. These findings represent a step toward a more complete map of end users' skills."

]]> Christopher Scaffidi Relating network topology to the robustness of centrality measures http://repository.cmu.edu/isr/857 http://repository.cmu.edu/isr/857 Wed, 23 May 2012 19:21:58 PDT Abstract: "This paper reports on a simulation study of social networks that investigated how network topology relates to the robustness of measures of system-level node centrality. This association is important to understand as data collected for social network analysis is often somewhat erroneous and may -- to an unknown degree -- misrepresent the actual true network. Consequently the values for measures of centrality calculated from the collected network data may also vary somewhat from those of the true network, possibly leading to incorrect suppositions. To explore the robustness, i.e., sensitivity, of network centrality measures in this circumstance, we conduct Monte Carlo experiments whereby we generate an initial network, perturb its copy with a specific type of error, then compare the centrality measures from two instances. We consider the initial network to represent a true network, while the perturbed represents the observed network. We apply a six-factor full-factorial block design for the overall methodology. We vary several control variables (network topology, size and density, as well as error type, form and level) to generate 10,000 samples each from both the set of all possible networks and possible errors within the parameter space. Results show that the topology of the true network can dramatically affect the robustness profile of the centrality measures. We found that across all permutations that cellular networks had a nearly identical profile to that of uniform-random networks, while the core-periphery networks had a considerably different profile. The centrality measures for the core-periphery networks are highly sensitive to small levels of error, relative to uniform and cellular topologies. Except in the case of adding edges, as the error increases, the robustness level for the 3 topologies deteriorate and ultimately converges."

]]> Terrill L. Frantz et al. Privacy indexes : a survey of Westin's studies http://repository.cmu.edu/isr/856 http://repository.cmu.edu/isr/856 Wed, 23 May 2012 19:21:34 PDT Abstract: "Since the late 1970 s Dr. Alan Westin has conducted over 30 privacy surveys. For each of his surveys, Westin has created one or more Privacy Indexes to summarize his results and to show trends in privacy concerns. Many privacy researchers are interested in using these privacy indexes as benchmarks to which they can compare their own survey results. However, the details of how the indexes were calculated have not been reported except in the original survey reports. These reports were originally distributed in paper form, and many are no longer readily available. We obtained paper copies of five of these survey reports and found a sixth report online. We also found summaries of eight additional reports online. Here we report on the methodology used each year to calculate the privacy indexes and draw some conclusions about which indexes can be used to infer privacy trends."

]]> Ponnurangam Kumaraguru et al. DyNetML : interchange format for rich social network data http://repository.cmu.edu/isr/855 http://repository.cmu.edu/isr/855 Wed, 23 May 2012 19:21:11 PDT Abstract: "We define a universal data interchange format to enable exchange of rich social network data and improve compatibility of analysis and visualization tools. DyNetML is an XML-derived language that provides means to express rich social network data. DyNetML also provides an extensible facility for linking anthropological, process description and other data with social networks. DyNetML has been implemented and in use by the CASOS group at Carnegie Mellon University as a data interchange format. We have also implemented parsing and conversion software for interoperability with other software packages."

]]> Maksim Tsvetovat et al. A network optimization approach for improving organizational design http://repository.cmu.edu/isr/854 http://repository.cmu.edu/isr/854 Wed, 23 May 2012 19:20:46 PDT Abstract: "Organizations are frequently designed and redesigned, often in efforts to improve performance or meet various managerial goals for coordination and communication. Such design is often done through the review of a few of [sic] options and the use of managerial and possibly personnel insight into how the new design might work. In contrast, we provide a systematic optimization based approach. In this approach, the user can pick one or more Dynamic Network Analysis (DNA) metrics and then use one or more of the available optimizers to find a design that more closely meets this ideal. The optimizer utilizes heuristic based optimization procedures to generate an optimized organizational design given a particular mission. DNA metrics, such as Communication Congruence, Resource Congruence, Cognitive Load, and Actual Workload, serve to define criteria. The Optimizer can perform multi-criteria optimization in order to improve several metrics simultaneously. Two optimization methods can be used -- Monte Carlo and Simulated Annealing, both of which are statistical methods of finding a global optimum. DNA metrics used in the optimizations are computed by ORA. This report describes this optimizer."

]]> Kathleen M. Carley et al. BioWar : a city-scale multi-agent network model of weaponized biological attacks http://repository.cmu.edu/isr/853 http://repository.cmu.edu/isr/853 Wed, 23 May 2012 19:20:21 PDT Abstract: "BioWar is scalable city-wide simulation, capable of simultaneously simulating the impact of background diseases, natural outbreaks and bioterrorism attacks on the population's behavior within a city. The multi-agent simulator includes social and institutional networks, weather and climate conditions, and the physical, economical, technological, communication, health, and governmental infrastructures which modulate disease outbreaks and individual behavior. Individual behaviors include health seeking, entertainment and work/school behavior. A wide variety of reports are generated based on user needs including absenteeism patterns, pharmaceutical purchases, doctor's office insurance claims reports, and hospital/emergency room reports. Sub-reports are available for specific sentinel groups including military personnel, first responders and health workers. Reports matching real world data streams and reports can be created for analyst or public health personnel including appropriate delays in generating said reports. This paper provides an overview of BioWar's current capabilities and information on the algorithms and data used to drive the simulation as of the Challenge 5 (C5) version."

]]> Kathleen M. Carley AutoMap 1.2 : extract, analyze, represent, and compare mental models from texts http://repository.cmu.edu/isr/852 http://repository.cmu.edu/isr/852 Wed, 23 May 2012 19:19:54 PDT Abstract: "AutoMap 1.2 is a network text analysis tool that extracts, analyzes, represents, and compares mental models from texts. Network text analysis is a specific text analysis method that encodes links between words in a text and builds a network of the linked words. Computational analysis of networks pulled out of textual data is a growing area of research for the following reasons: The large and still growing number of electronically available texts requires the investigation of appropriate methods and tools to analyze large scale collections of texts effectively and efficiently. Today's communication theories are oriented towards complex, large-scale systems, and therefore require methods that provide multi-level access to the meaning of textual data. AutoMap helps users to analyze textual data according to the current requirements."

]]> Jana Diesner et al. The trading agent competition supply chain management game http://repository.cmu.edu/isr/851 http://repository.cmu.edu/isr/851 Wed, 23 May 2012 19:19:29 PDT Abstract: "This report describes the Trading Agent Competition Supply Chain Management Game (TAC SCM). Based on this document a game server and agent-ware were developed in collaboration with the Swedish Institute of Computer Science (SICS) and can be found at http://www.sics.se/tac. This platform was used in the 2003 Trading Agent Competition held during IJCAI 2003, in Acapulco, Mexico."

]]> Raghu Arunachalam Finding lists of people on the Web http://repository.cmu.edu/isr/850 http://repository.cmu.edu/isr/850 Wed, 23 May 2012 19:19:04 PDT Abstract: "Among the vast amounts of personal information published on the World Wide Web ('Web') and indexed by search engines are lists of names of people. Examples include employees at companies, students enrolled in universities, officers in the military, law enforcement personnel, members of social organizations, and lists of acquaintances. Knowing who works where, attends what, or affiliates with whom provides strategic knowledge to competitors, marketers, and government surveillance efforts. However, finding online rosters of people does not lend itself to keyword lookup on search engines because the keywords tend to be common expressions such as 'employees' or 'students.' A typical search often retrieves hundreds of Web pages requiring many hours of human inspection to locate a page containing a list of names. As a result, people may falsely believe online rosters provide more privacy than they do. This paper presents RosterFinder, a set of simple algorithms for locating Web pages that consist predominately of a list of names. The specific names are not known beforehand. RosterFinder works by identifying rosters from candidate Web pages based on the ratio of distinct known names to distinct words appearing in the page. Accurate classification by RosterFinder depends on the set of names used. Results are reported on real Web pages using: (1) dictionary lookup employing a limited set of known names; and, (2) dictionary lookup on utilizing an extensive set of known names. Privacy implications are discussed using the example of FERPA and online student rosters."

]]> Latanya Sweeney Navigating computer science research through waves of privacy concerns : discussions among computer scientists at Carnegie Mellon University http://repository.cmu.edu/isr/849 http://repository.cmu.edu/isr/849 Wed, 23 May 2012 19:18:39 PDT Abstract: "Computer Science research and practice are raising growing privacy concerns among the public and government. Computer technology's increasing ability to capture, organize, interpret and share data about individuals raises questions about what privacy practices computer science researchers should adopt, if any. These issues are already very real in ongoing research projects in the School of Computer Science (SCS) at Carnegie Mellon University, from mining databases of individual transactions, to studying how people use the web, to mounting cameras in lounges, to building hallway robots that capture data about passers by, to building intelligent workstation assistants that learn user habits. This paper introduces the nature of privacy concerns often related to computer science research, explains potential benefits and risks (especially of abuse and misuse) and examines traditional and innovative methods for providing privacy assurances in research. Examples are provided from projects at Carnegie Mellon's School of Computer Science."

]]> Latanya Sweeney Semantic web technologies to reconcile privacy and context awareness http://repository.cmu.edu/isr/848 http://repository.cmu.edu/isr/848 Wed, 23 May 2012 19:18:13 PDT Abstract: "Increasingly, application developers are looking for ways to provide users with higher levels of personalization that capture different elements of a user's operating context, such as her location, the task that she is currently engaged in, who her colleagues are, etc. While there are many sources of contextual information, they tend to vary from one user to another and also over time. Different users may rely on different location tracking functionality provided by different cell phone operators; they may use different calendar systems, etc. In this article, we describe work on a Semantic e-Wallet aimed at supporting automated identification and access of personal resources, each represented as a Semantic Web Service. A key objective is to provide a Semantic Web environment for open access to a user's contextual resources, thereby reducing the costs associated with the development and maintenance of context-aware applications. A second objective is, through Semantic Web technologies, to empower users to selectively control who has access to their contextual information and under which conditions. This work has been carried out in the context of myCampus, a context-aware environment aimed at enhancing everyday campus life. Empirical results obtained on Carnegie Mellon's campus are discussed."

]]> Fabien L. Gandon et al. A framework for synthesis of human gait oscillation using Intelligent Gait Oscillation Detector (IGOD) http://repository.cmu.edu/isr/847 http://repository.cmu.edu/isr/847 Fri, 22 Jul 2011 13:11:24 PDT The main objective of this paper illustrates an elementary concept about the designing, development and implementation of a bio-informatics diagnostic tool which understands and analyzes the human gait oscillation in order to provide an insight on human bi-pedal locomotion and its stability. A multi sensor device for detection of gait oscillations during human locomotion has been developed effectively. It has been named “IGOD”, an acronym of the “Intelligent Gait Oscillation Detector”. It ensures capturing of different person’s walking pattern in a very elegant way. This device would be used for creating a database of gait oscillations which could be extensively applied in several implications. The preliminary acquired data for eight major joints of a human body have been presented significantly. The electronic circuit has been attached to IGOD device in order to customize the proper calibration of every joint angle eventually.

]]> Soumik Mondal et al. Designing CPG For Biped Locomotion Control Using Nonlinear Dynamical Theory http://repository.cmu.edu/isr/846 http://repository.cmu.edu/isr/846 Fri, 22 Jul 2011 13:11:17 PDT Generating biped locomotion patterns is a difficult task because maintaining balance on two legs is not easy. Nature has given humans a very stable and efficient locomotion. Therefore it is a good idea to take inspiration from biological world for developing natural and efficient walking patterns. In humans, Central Pattern Generator (CPG) is responsible for many rhythmic activities like locomotion, chewing, breathing, digestion etc.

In this work, a bipedal locomotion controller for simple walk is developed by drawing inspiration from biological CPG. The approach used for the work is nonlinear dynamic theory. The four body joints used for the modeling are two hip joints and two knee joints. The controller model is composed of four coupled Rayleigh oscillators, where each oscillator drives one joint. The four oscillators are coupled with each other. To search the values of CPG parameters genetic algorithm is proposed. Walking trajectories of adult humans are utilized to design the fitness function for genetic algorithm.

]]> Preeti Kanyal Efficient Temporal Pattern Mining for Humanoid Robot http://repository.cmu.edu/isr/845 http://repository.cmu.edu/isr/845 Fri, 22 Jul 2011 13:11:10 PDT Pattern mining in temporal databases is one of the challenging platform which holds attention when some ordered sequences are frequently occurred at different time instances in the dataset. We have found temporal patterns in humanoid robot dataset of HOAP-2 (Humanoid Open-Architecture Platform) which generates different motions through recurring sequences of various joint associations. For mining temporal patterns in that dataset we have proposed a method. This method uses FP-Temporal and SH(Soft-Hyperlinked)-Temporal mining algorithm as pattern growth methods for generating temporal association rules for various motion patterns of HOAP-2. Brief performance analysis shows that SH-Temporal is much efficient than FP-Temporal for such datasets and works significantly for mining sequentially associative temporal patterns in terms of temporal association rules.

]]> Upasna Singh et al. Development of Adaptive Modular Active Leg (AMAL) Using Bipedal Robotics Technology http://repository.cmu.edu/isr/844 http://repository.cmu.edu/isr/844 Fri, 22 Jul 2011 13:11:03 PDT The objective of the work presented here is to develop a low cost active above knee prosthetic device exploiting bipedal robotics technology which will work utilizing the available biological motor control circuit properly integrated with a Central Pattern Generator (CPG) based control scheme. The approach is completely different from the existing Active Prosthetic devices, designed primarily as standalone systems utilizing multiple sensors and embedded rigid control schemes. In this research, first we designed a fuzzy logic based methodology for offering suitable gait pattern for an amputee, followed by formulating a suitable algorithm for designing a CPG, based on Rayleigh’s oscillator. An indigenous probe, Humanoid Gait Oscillator Detector (HGOD) has been designed for capturing gait patterns from various individuals of different height, weight and age. These data are used to design a Fuzzy inference system which generates most suitable gait pattern for an amputee. The output of the Fuzzy inference system is used for designing a CPG best suitable for the amputee. We then developed a CPG based control scheme for calculating the damping profile in real time for maneuvering a prosthetic device called AMAL (Adaptive Modular Active Leg).

Also a number of simulation results are presented which show the stable behavior of knee and hip angles and determine the stable limit cycles of the network.

]]> Gora Nandi et al.