Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Research Collection School Of Computing and Information Systems

Discipline
Keyword
Publication Year

Articles 3121 - 3150 of 4266

Full-Text Articles in Entire DC Network

Designing Leakage-Resilient Password Entry On Touchscreen Mobile Devices, Qiang Yan, Jin Han, Yingjiu Li, Jianying Zhou, Robert H. Deng May 2013

Designing Leakage-Resilient Password Entry On Touchscreen Mobile Devices, Qiang Yan, Jin Han, Yingjiu Li, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

Touchscreen mobile devices are becoming commodities as the wide adoption of pervasive computing. These devices allow users to access various services at anytime and anywhere. In order to prevent unauthorized access to these services, passwords have been pervasively used in user authentication. However, password-based authentication has intrinsic weakness in password leakage. This threat could be more serious on mobile devices, as mobile devices are widely used in public places. Most prior research on improving leakage resilience of password entry focuses on desktop computers, where specific restrictions on mobile devices such as small screen size are usually not addressed. Meanwhile, additional …


Cost-Sensitive Double Updating Online Learning And Its Application To Online Anomaly Detection, Peilin Zhao, Steven C. H. Hoi May 2013

Cost-Sensitive Double Updating Online Learning And Its Application To Online Anomaly Detection, Peilin Zhao, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

Although both cost-sensitive classification and online learning have been well studied separately in data mining and machine learning, there was very few comprehensive study of cost-sensitive online classification in literature. In this paper, we formally investigate this problem by directly optimizing cost-sensitive measures for an online classification task. As the first comprehensive study, we propose the Cost-Sensitive Double Updating Online Learning (CSDUOL) algorithms, which explores a recent double updating technique to tackle the online optimization task of cost-sensitive classification by maximizing the weighted sum or minimizing the weighted misclassification cost. We theoretically analyze the cost-sensitive measure bounds of the proposed …


Strong Location Privacy: A Case Study On Shortest Path Queries [Invited Paper], Kyriakos Mouratidis Apr 2013

Strong Location Privacy: A Case Study On Shortest Path Queries [Invited Paper], Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

The last few years have witnessed an increasing availability of location-based services (LBSs). Although particularly useful, such services raise serious privacy concerns. For example, exposing to a (potentially untrusted) LBS the client's position may reveal personal information, such as social habits, health condition, shopping preferences, lifestyle choices, etc. There is a large body of work on protecting the location privacy of the clients. In this paper, we focus on shortest path queries, describe a framework based on private information retrieval (PIR), and conclude with open questions about the practicality of PIR and other location privacy approaches.


Delayed Insertion And Rule Effect Moderation Of Domain Knowledge For Reinforcement Learning, Teck-Hou Teng, Ah-Hwee Tan Apr 2013

Delayed Insertion And Rule Effect Moderation Of Domain Knowledge For Reinforcement Learning, Teck-Hou Teng, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Though not a fundamental pre-requisite to efficient machine learning, insertion of domain knowledge into adaptive virtual agent is nonetheless known to improve learning efficiency and reduce model complexity. Conventionally, domain knowledge is inserted prior to learning. Despite being effective, such approach may not always be feasible. Firstly, the effect of domain knowledge is assumed and can be inaccurate. Also, domain knowledge may not be available prior to learning. In addition, the insertion of domain knowledge can frame learning and hamper the discovery of more effective knowledge. Therefore, this work advances the use of domain knowledge by proposing to delay the …


Roundtriprank: Graph-Based Proximity With Importance And Specificity, Yuan Fang, Kevin Chen-Chuan Chang, Hady W. Lauw Apr 2013

Roundtriprank: Graph-Based Proximity With Importance And Specificity, Yuan Fang, Kevin Chen-Chuan Chang, Hady W. Lauw

Research Collection School Of Computing and Information Systems

Graph-based proximity has many applications with different ranking needs. However, most previous works only stress the sense of importance by finding "popular” results for a query. Often times important results are overly general without being well-tailored to the query, lacking a sense of specificity— which only emerges recently. Even then, the two senses are treated independently, and only combined empirically. In this paper, we generalize the well-studied importance-based random walk into a round trip and develop RoundTripRank, seamlessly integrating specificity and importance in one coherent process. We also recognize the need for a flexible trade-off between the two senses, and …


Vistruclizer: A Structural Visualizer For Multi-Dimensional Social Networks, Bingtian Dai, Agus Trisnajaya Kwee, Ee Peng Lim Apr 2013

Vistruclizer: A Structural Visualizer For Multi-Dimensional Social Networks, Bingtian Dai, Agus Trisnajaya Kwee, Ee Peng Lim

Research Collection School Of Computing and Information Systems

With the popularity of Web 2.0 sites, social networks today increasingly involve different kinds of relationships among different types of users in a single network. Such social networks are said to be multi-dimensional. Analyzing multi-dimensional networks is a challenging research task that requires intelligent visualization techniques. In this paper, we therefore propose a visual analytics tool called ViStruclizer to analyze structures embedded in a multi-dimensional social network. ViStruclizer incorporates structure analyzers that summarize social networks into both node clusters each representing a set of users, and edge clusters representing relationships between users in the node clusters. ViStruclizer supports user interactions …


Cross-Domain Password-Based Authenticated Key Exchange Revisited, Liqun Chen, Hoon Wei Lim, Guomin Yang Apr 2013

Cross-Domain Password-Based Authenticated Key Exchange Revisited, Liqun Chen, Hoon Wei Lim, Guomin Yang

Research Collection School Of Computing and Information Systems

We revisit the problem of secure cross-domain communication between two users belonging to different security domains within an open and distributed environment. Existing approaches presuppose that either the users are in possession of public key certificates issued by a trusted certificate authority (CA), or the associated domain authentication servers share a long-term secret key. In this paper, we propose a generic framework for designing four-party password-based authenticated key exchange (4PAKE) protocols. Our framework takes a different approach from previous work. The users are not required to have public key certificates, but they simply reuse their login passwords they share with …


Enabling An Integrated Rate-Temporal Learning Scheme On Memristor, Wei He, Kejie Huang, Ning Ning, Kiruthika Ramanathan, Guoqi Li, Yu Jiang, Jiayin Sze, Luping Shi, Rong Zhao, Jing Pei Apr 2013

Enabling An Integrated Rate-Temporal Learning Scheme On Memristor, Wei He, Kejie Huang, Ning Ning, Kiruthika Ramanathan, Guoqi Li, Yu Jiang, Jiayin Sze, Luping Shi, Rong Zhao, Jing Pei

Research Collection School Of Computing and Information Systems

Learning scheme is the key to the utilization of spike-based computation and the emulation of neural/synaptic behaviors toward realization of cognition. The biological observations reveal an integrated spike time- and spike rate-dependent plasticity as a function of presynaptic firing frequency. However, this integrated rate-temporal learning scheme has not been realized on any nano devices. In this paper, such scheme is successfully demonstrated on a memristor. Great robustness against the spiking rate fluctuation is achieved by waveform engineering with the aid of good analog properties exhibited by the iron oxide-based memristor. The spike-time-dependence plasticity (STDP) occurs at moderate presynaptic firing frequencies …


Circular Reranking For Visual Search, Ting Yao, Chong-Wah Ngo Apr 2013

Circular Reranking For Visual Search, Ting Yao, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Search reranking is regarded as a common way to boost retrieval precision. The problem nevertheless is not trivial especially when there are multiple features or modalities to be considered for search, which often happens in image and video retrieval. This paper proposes a new reranking algorithm, named circular reranking, that reinforces the mutual exchange of information across multiple modalities for improving search performance, following the philosophy that strong performing modality could learn from weaker ones, while weak modality does benefit from interacting with stronger ones. Technically, circular reranking conducts multiple runs of random walks through exchanging the ranking scores among …


Dynamic Label Propagation In Social Networks, Juan Du, Feida Zhu, Ee Peng Lim Apr 2013

Dynamic Label Propagation In Social Networks, Juan Du, Feida Zhu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Label propagation has been studied for many years, starting from a set of nodes with labels and then propagating to those without labels. In social networks, building complete user profiles like interests and affiliations contributes to the systems like link prediction, personalized feeding, etc. Since the labels for each user are mostly not filled, we often employ some people to label these users. And therefore, the cost of human labeling is high if the data set is large. To reduce the expense, we need to select the optimal data set for labeling, which produces the best propagation result. In this …


Arraytrack: A Fine-Grained Indoor Location System, Jie Xiong, Kyle Jamieson Apr 2013

Arraytrack: A Fine-Grained Indoor Location System, Jie Xiong, Kyle Jamieson

Research Collection School Of Computing and Information Systems

With myriad augmented reality, social networking, and retail shopping applications all on the horizon for the mobile handheld, a fast and accurate location technology will become key to a rich user experience. When roaming outdoors, users can usually count on a clear GPS signal for accurate location, but indoors, GPS often fades, and so up until recently, mobiles have had to rely mainly on rather coarse-grained signal strength readings. What has changed this status quo is the recent trend of dramatically increasing numbers of antennas at the indoor access point, mainly to bolster capacity and coverage with multiple-input, multiple-output (MIMO) …


Robust Image Analysis With Sparse Representation On Quantized Visual Features, Bingkun Bao, Guangyu Zhu, Jialie Shen, Shuicheng Yan Mar 2013

Robust Image Analysis With Sparse Representation On Quantized Visual Features, Bingkun Bao, Guangyu Zhu, Jialie Shen, Shuicheng Yan

Research Collection School Of Computing and Information Systems

Recent techniques based on Sparse Representation (SR) have demonstrated promising performance on high-level visual recognition, exemplified by the high-accuracy face recognition under occlusions and other sparse corruptions [1]. Most research in this area has focused on classification algorithms using raw image pixels, and very few have been proposed to utilize the quantized visual features, such as the popular Bagof- Words (BOW) feature abstraction. In such cases, besides the inherent quantization errors, ambiguity associated with visual word assignment and mis-detection of feature points due to factors such as visual occlusions and noises, constitutes the major causes to the dense corruptions of …


Data Visualization On Interactive Surfaces: A Research Agenda, Petra Isenberg, Tobias Isenberg, Tobias Hesselmann, Bongshin Lee, Ulrich Von Zadow, Anthony Tang Mar 2013

Data Visualization On Interactive Surfaces: A Research Agenda, Petra Isenberg, Tobias Isenberg, Tobias Hesselmann, Bongshin Lee, Ulrich Von Zadow, Anthony Tang

Research Collection School Of Computing and Information Systems

Interactive tabletops and surfaces (ITSs) provide rich opportunities for data visualization and analysis and consequently are used increasingly in such settings. A research agenda of some of the most pressing challenges related to visualization on ITSs emerged from discussions with researchers and practitioners in human-computer interaction, computer-supported collaborative work, and a variety of visualization fields at the 2011 Workshop on Data Exploration for Interactive Surfaces (Dexis 2011)


Flip-Invariant Sift For Copy And Object Detection, Wan-Lei Zhao, Chong-Wah Ngo Mar 2013

Flip-Invariant Sift For Copy And Object Detection, Wan-Lei Zhao, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Scale-invariant feature transform (SIFT) feature has been widely accepted as an effective local keypoint descriptor for its invariance to rotation, scale, and lighting changes in images. However, it is also well known that SIFT, which is derived from directionally sensitive gradient fields, is not flip invariant. In real-world applications, flip or flip-like transformations are commonly observed in images due to artificial flipping, opposite capturing viewpoint, or symmetric patterns of objects. This paper proposes a new descriptor, named flip-invariant SIFT (or F-SIFT), that preserves the original properties of SIFT while being tolerant to flips. F-SIFT starts by estimating the dominant curl …


Semi-Supervised Heterogeneous Fusion For Multimedia Data Co-Clustering, Lei Meng, Ah-Hwee Tan, Dong Xu Mar 2013

Semi-Supervised Heterogeneous Fusion For Multimedia Data Co-Clustering, Lei Meng, Ah-Hwee Tan, Dong Xu

Research Collection School Of Computing and Information Systems

Co-clustering is a commonly used technique for tapping the rich meta-information of multimedia web documents, including category, annotation, and description, for associative discovery. However, most co-clustering methods proposed for heterogeneous data do not consider the representation problem of short and noisy text and their performance is limited by the empirical weighting of the multi-modal features. In this paper, we propose a generalized form of Heterogeneous Fusion Adaptive Resonance Theory, called GHF-ART, for co-clustering of large-scale web multimedia documents. By extending the two-channel Heterogeneous Fusion ART (HF-ART) to multiple channels, GHF-ART is designed to handle multimedia data with an arbitrarily rich …


Predicting Project Outcome Leveraging Socio-Technical Network Patterns, Didi Surian, Yuan Tian, David Lo, Hong Cheng, Ee Peng Lim Mar 2013

Predicting Project Outcome Leveraging Socio-Technical Network Patterns, Didi Surian, Yuan Tian, David Lo, Hong Cheng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

There are many software projects started daily, some are successful, while others are not. Successful projects get completed, are used by many people, and bring benefits to users. Failed projects do not bring similar benefits. In this work, we are interested in developing an effective machine learning solution that predicts project outcome (i.e., success or failures) from developer socio-technical network. To do so, we investigate successful and failed projects to find factors that differentiate the two. We analyze the socio-technical aspect of the software development process by focusing at the people that contribute to these projects and the interactions among …


Empirical Evaluation Of Bug Linking, Tegawende F. Bissyande, Ferdian Thung, Shaowei Wang, David Lo, Lingxiao Jiang, Laurent Reveillere Mar 2013

Empirical Evaluation Of Bug Linking, Tegawende F. Bissyande, Ferdian Thung, Shaowei Wang, David Lo, Lingxiao Jiang, Laurent Reveillere

Research Collection School Of Computing and Information Systems

To collect software bugs found by users, development teams often setup bug trackers using systems such as Bugzilla. Developers would then fix some of the bugs and commit corresponding code changes into version control systems such as svn or git. Unfortunately, the links between bug reports and code changes are missing for many software projects as the bug tracking and version control systems are often maintained separately. Yet, linking bug reports to fix commits is important as it could shed light into the nature of bug fixing processes and expose patterns in software management. Bug linking solutions, such as ReLink, …


An Empirical Study On Developer Interactions In Stackoverflow, Shaowei Wang, David Lo, Lingxiao Jiang Mar 2013

An Empirical Study On Developer Interactions In Stackoverflow, Shaowei Wang, David Lo, Lingxiao Jiang

Research Collection School Of Computing and Information Systems

StackOverflow provides a popular platform where developers post and answer questions. Recently, Treude et al. manually label 385 questions in StackOverflow and group them into 10 categories based on their contents. They also analyze how tags are used in StackOverflow. In this study, we extend their work to obtain a deeper understanding on how developers interact with one another on such a question and answer web site. First, we analyze the distributions of developers who ask and answer questions. We also investigate if there is a segregation of the StackOverflow community into questioners and answerers. We also perform automated text …


Infrastructure-Assisted Smartphone-Based Adl Recognition In Multi-Inhabitant Smart Environments, Nirmalya Roy, Archan Misra, Diane Cook Mar 2013

Infrastructure-Assisted Smartphone-Based Adl Recognition In Multi-Inhabitant Smart Environments, Nirmalya Roy, Archan Misra, Diane Cook

Research Collection School Of Computing and Information Systems

We propose a hybrid approach for recognizing complex Activities of Daily Living that lie between the two extremes of intensive use of body-worn sensors and the use of infrastructural sensors. Our approach harnesses the power of infrastructural sensors (e.g., motion sensors) to provide additional `hidden' context (e.g., room-level location) of an individual and combines this context with smartphone-based sensing of micro-level postural/locomotive states. The major novelty is our focus on multi-inhabitant environments, where we show how spatiotemporal constraints can be used to significantly improve the accuracy and computational overhead of traditional coupled-HMM based approaches. Experimental results on a smart home …


Adoption Of Software Testing In Open Source Projects: A Preliminary Study On 50,000 Projects, Pavneet Singh Kochhar, Tegawende F. Bissyande, David Lo, Lingxiao Jiang Mar 2013

Adoption Of Software Testing In Open Source Projects: A Preliminary Study On 50,000 Projects, Pavneet Singh Kochhar, Tegawende F. Bissyande, David Lo, Lingxiao Jiang

Research Collection School Of Computing and Information Systems

In software engineering, testing is a crucial activity that is designed to ensure the quality of program code. For this activity, development teams spend substantial resources constructing test cases to thoroughly assess the correctness of software functionality. What is however the proportion of open source projects that include test cases? What kind of projects are more likely to include test cases? In this study, we explore 50,000 projects and investigate the correlation between the presence of test cases and various project development characteristics, including the lines of code and the size of development teams.


Almost Touching: Parent-Child Remote Communication Using The Sharetable System, Svetlana Yarosh, Anthony Tang, Sanika Mokashi, Gregory D. Abowd Mar 2013

Almost Touching: Parent-Child Remote Communication Using The Sharetable System, Svetlana Yarosh, Anthony Tang, Sanika Mokashi, Gregory D. Abowd

Research Collection School Of Computing and Information Systems

We deployed the ShareTable - a system that provides easy-to-initiate videochat and a shared tabletop task space - in four divorced households. Throughout the month of its use, the families employed the ShareTable to participate in shared activities, share emotional moments, and communicate closeness through metaphorical touch. The ShareTable provided a number of advantages over the phone and was easier to use than standard videoconferencing. However, it did also introduce concerns over privacy and new sources of conflict about appropriate calling practices. We relate our findings to the larger research landscape and present implications for future work.


A Self-Training Framework For Automatic Identification Of Exploratory Dialogue, Zhongyu Wei, Yulan He, Simon Shum, Rebecca Ferguson, Wei Gao, Kam-Fai Wong Mar 2013

A Self-Training Framework For Automatic Identification Of Exploratory Dialogue, Zhongyu Wei, Yulan He, Simon Shum, Rebecca Ferguson, Wei Gao, Kam-Fai Wong

Research Collection School Of Computing and Information Systems

The dramatic increase in online learning materials over the last decade has made it difficult for individuals to locate information they need. Until now, researchers in the field of Learning Analytics have had to rely on the use of manual approaches to identify exploratory dialogue. This type of dialogue is desirable in online learning environments, since training learners to use it has been shown to improve learning outcomes. In this paper, we frame the problem of exploratory dialogue detection as a binary classification task, classifying a given contribution to an online dialogue as exploratory or non-exploratory. We propose a self-training …


Accountable Authority Identity-Based Encryption With Public Traceability, Junzuo Lai, Robert H. Deng, Yunlei Zhao, Jian Weng Mar 2013

Accountable Authority Identity-Based Encryption With Public Traceability, Junzuo Lai, Robert H. Deng, Yunlei Zhao, Jian Weng

Research Collection School Of Computing and Information Systems

At Crypto’07, Goyal introduced the notion of accountable authority identity-based encryption (A-IBE) in order to mitigate the inherent key escrow problem in identity-based encryption, and proposed two concrete constructions. In an A-IBE system, if the private key generator (PKG) distributes a decryption key or produces an unauthorized decryption box for a user maliciously, it runs the risk of being caught and sued in the court of law with the help of a tracing algorithm. Subsequent efforts focused on constructions of A-IBE schemes with enhanced security. In these A-IBE constructions, the tracing algorithm needs to take a user’s decryption key as …


Confidence Weighted Mean Reversion Strategy For Online Portfolio Selection, Bin Li, Steven C. H. Hoi, Peilin Zhao, Vivekanand Gopalkrishnan Mar 2013

Confidence Weighted Mean Reversion Strategy For Online Portfolio Selection, Bin Li, Steven C. H. Hoi, Peilin Zhao, Vivekanand Gopalkrishnan

Research Collection School Of Computing and Information Systems

Online portfolio selection has been attracting increasing attention from the data mining and machine learning communities. All existing online portfolio selection strategies focus on the first order information of a portfolio vector, though the second order information may also be beneficial to a strategy. Moreover, empirical evidence shows that relative stock prices may follow the mean reversion property, which has not been fully exploited by existing strategies. This article proposes a novel online portfolio selection strategy named Confidence Weighted Mean Reversion (CWMR). Inspired by the mean reversion principle in finance and confidence weighted online learning technique in machine learning, CWMR …


Kinectarms: A Toolkit For Capturing And Displaying Arm Embodiments In Distributed Tabletop Groupware, Aaron Genest, Carl Gutwin, Anthony Tang, Michael Kalyn, Zenja Ivkovic Feb 2013

Kinectarms: A Toolkit For Capturing And Displaying Arm Embodiments In Distributed Tabletop Groupware, Aaron Genest, Carl Gutwin, Anthony Tang, Michael Kalyn, Zenja Ivkovic

Research Collection School Of Computing and Information Systems

Gestures are a ubiquitous part of human communication over tables, but when tables are distributed, gestures become difficult to capture and represent. There are several problems: extracting arm images from video, representing the height of the gesture, and making the arm embodiment visible and understandable at the remote table. Current solutions to these problems are often expensive, complex to use, and difficult to set up. We have developed a new toolkit - KinectArms - that quickly and easily captures and displays arm embodiments. KinectArms uses a depth camera to segment the video and determine gesture height, and provides several visual …


I Can Be You: Questioning The Use Of Keystroke Dynamics As Biometrics, Chee Meng Tey, Payas Gupta, Debin Gao Feb 2013

I Can Be You: Questioning The Use Of Keystroke Dynamics As Biometrics, Chee Meng Tey, Payas Gupta, Debin Gao

Research Collection School Of Computing and Information Systems

Keystroke dynamics refer to information about the typing patterns of individuals, such as the relative timing when the individual presses and releases each key. Prior studies suggest that such patterns are unique and cannot be easily imitated. This lays the foundation for the use of keystroke biometrics in authentication systems. The research effort in this area has thus far focused on novel detection techniques to differentiate between legitimate users and imposters. In this paper, we demonstrate a novel feedback and training interface named Mimesis. Mimesis provides both positive and negative feedback on the differences between a submitted pattern vs. a …


Authscan: Automatic Extraction Of Web Authentication Protocols From Implementations, Guangdong Bai, Jike Lei, Guozhu Meng, Sai Sathyanarayan Venkatraman, Prateek Saxena, Jun Sun, Yang Liu, Jin Song Dong Feb 2013

Authscan: Automatic Extraction Of Web Authentication Protocols From Implementations, Guangdong Bai, Jike Lei, Guozhu Meng, Sai Sathyanarayan Venkatraman, Prateek Saxena, Jun Sun, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Ideally, security protocol implementations should be formally verified before they are deployed. However, this is not true in practice. Numerous high-profile vulnerabilities have been found in web authentication protocol implementations, especially in single-sign on (SSO) protocols implementations recently. Much of the prior work on authentication protocol verification has focused on theoretical foundations and building scalable verification tools for checking manually-crafted specifications [17, 18, 44]. In this paper, we address a complementary problem of automatically extracting specifications from implementations. We propose AUTHSCAN, an end-to-end platform to automatically recover authentication protocol specifications from their implementations. AUTHSCAN finds a total of 7 security …


K-Pop Live: Social Networking & Language Learning Platform, Thomas Chua, Chin Leng Ong, Kian Ming Png, Aloysius Lau, Houston Toh, Feida Zhu, Kyong Jin Shim, Ee-Peng Lim Feb 2013

K-Pop Live: Social Networking & Language Learning Platform, Thomas Chua, Chin Leng Ong, Kian Ming Png, Aloysius Lau, Houston Toh, Feida Zhu, Kyong Jin Shim, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

K-Pop live is a social networking and language learning platform developed by an undergraduate student team from Singapore Management University. K-Pop live aims to combine social media together with gamification to promote Korean culture. It consolidates all relevant Tweets from Twitter as well as videos from YouTube. The platform allows the user to connect with his friends who share similar interests in terms of K-pop artists and music.


Simple Identity-Based Encryption With Mediated Rsa, Xuhua Ding, Gene Tsudik Feb 2013

Simple Identity-Based Encryption With Mediated Rsa, Xuhua Ding, Gene Tsudik

Research Collection School Of Computing and Information Systems

Identity-based encryption (IBE) [5] and digital signatures are important tools in modern secure communication. In general, identity-based cryptographic methods facilitate easy introduction of public key cryptography by allowing an entity’s public key to be derived from some arbitrary identification value such as an email address or a phone number. Identity-based cryptography greatly reduces the need for, and reliance on, public key certificates. Mediated RSA (mRSA) [4] is a simple and practical method of splitting RSA private keys between the user and the Security Mediator (SEM). Neither the user nor the SEM can cheat one another since each signature or decryption …


Combining Crowdsourcing And Google Street View To Identify Street-Level Accessibility Problems, Kotaro Hara, Victoria Le, Jon Froehlich Feb 2013

Combining Crowdsourcing And Google Street View To Identify Street-Level Accessibility Problems, Kotaro Hara, Victoria Le, Jon Froehlich

Research Collection School Of Computing and Information Systems

Jon FroehlichAbstractPoorly maintained sidewalks, missing curb ramps, and other obstacles pose considerable accessibility challenges; however, there are currently few, if any, mechanisms to determine accessible areas of a city a priori. In this paper, we investigate the feasibility of using untrained crowd workers from Amazon Mechanical Turk (turkers) to find, label, and assess sidewalk accessibility problems in Google Street View imagery. We report on two studies: Study 1 examines the feasibility of this labeling task with six dedicated labelers including three wheelchair users; Study 2 investigates the comparative performance of turkers. In all, we collected 13,379 labels and 19,189 verification …