Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Computer Sciences (7219)
- Databases and Information Systems (2960)
- Software Engineering (1895)
- Artificial Intelligence and Robotics (1075)
- Numerical Analysis and Scientific Computing (963)
-
- Information Security (937)
- Engineering (795)
- Social and Behavioral Sciences (772)
- Graphics and Human Computer Interfaces (676)
- Business (670)
- Theory and Algorithms (454)
- Computer Engineering (410)
- Operations Research, Systems Engineering and Industrial Engineering (366)
- Programming Languages and Compilers (309)
- Communication (301)
- OS and Networks (300)
- Social Media (244)
- Public Affairs, Public Policy and Public Administration (202)
- Environmental Sciences (168)
- Data Storage Systems (164)
- Medicine and Health Sciences (163)
- Transportation (163)
- International and Area Studies (153)
- Management Information Systems (153)
- Asian Studies (151)
- Education (145)
- Technology and Innovation (126)
- E-Commerce (120)
- Finance and Financial Management (98)
- Keyword
-
- Deep learning (109)
- Machine learning (105)
- Artificial intelligence (77)
- Singapore (76)
- Social media (73)
-
- Data mining (62)
- Cloud computing (57)
- Reinforcement learning (54)
- Optimization (51)
- Security (51)
- Privacy (50)
- Twitter (49)
- Online learning (48)
- Software engineering (47)
- Visualization (46)
- Deep Learning (45)
- Empirical study (45)
- Neural networks (45)
- Task analysis (44)
- Access control (41)
- Feature extraction (41)
- Algorithms (40)
- Blockchain (39)
- Semantics (39)
- Sustainability (39)
- Classification (38)
- Android (35)
- Anomaly detection (35)
- Clustering (35)
- Collaboration (35)
- Publication Year
- Publication
-
- Research Collection School Of Computing and Information Systems (6884)
- Dissertations and Theses Collection (Open Access) (128)
- Research Collection Lee Kong Chian School Of Business (94)
- Research Collection School of Social Sciences (48)
- Research Collection College of Integrative Studies (44)
-
- Perspectives@SMU (38)
- Asian Management Insights (35)
- Research Collection Yong Pung How School Of Law (30)
- Research Collection School Of Accountancy (23)
- Research Collection School Of Economics (22)
- Dissertations and Theses Collection (15)
- SMU Press Releases (12)
- MITB Thought Leadership Series (11)
- Research@SMU: Connecting the Dots (10)
- Research Collection School of Computing and Information Systems (9)
- LARC Research Publications (7)
- Research Collection Library (6)
- Social Space (5)
- SMU Research Data (4)
- Sim Kee Boon Institute for Financial Economics (4)
- 2024 AI for Research Week (3)
- Centre for Computational Law (3)
- CMP Research (2)
- Centre for AI & Data Governance (2)
- Research Collection Office of Research (2)
- Library Events (1)
- Oral History Collection (1)
- ROSA Journal Articles and Publications (1)
- Research Collection School of Accountancy (1)
- Research@SMU Infographics (1)
- Publication Type
- File Type
Articles 6961 - 6990 of 7446
Full-Text Articles in Physical Sciences and Mathematics
Taking Dcop To The Real World: Efficient Complete Solutions For Distributed Event Scheduling, Rajiv Maheswaran, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Varakantham
Taking Dcop To The Real World: Efficient Complete Solutions For Distributed Event Scheduling, Rajiv Maheswaran, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Varakantham
Research Collection School Of Computing and Information Systems
Distributed Constraint Optimization (DCOP) is an elegant formalism relevant to many areas in multiagent systems, yet complete algorithms have not been pursued for real world applications due to perceived complexity. To capably capture a rich class of complex problem domains, we introduce the Distributed Multi-Event Scheduling (DiMES) framework and design congruent DCOP formulations with binary constraints which are proven to yield the optimal solution. To approach real-world efficiency requirements, we obtain immense speedups by improving communication structure and precomputing best case bounds. Heuristics for generating better communication structures and calculating bound in a distributed manner are provided and tested on …
Infosemm: Infosys It Security Maturity Model: A Report, Arcot Desai Narasimhalu, N. Dayasindhu, Raghavan Subramanian
Infosemm: Infosys It Security Maturity Model: A Report, Arcot Desai Narasimhalu, N. Dayasindhu, Raghavan Subramanian
Research Collection School Of Computing and Information Systems
Businesses are faced with a continuing battle related to cyber security related issues ranging from cyber attacks all the way to cyber (information) war. These issues affect result in information, system, reputation, and revenue related risks. These risks arise because of vulnerabilities introduced in three major parts of the enterprise – infrastructure, intelligence and practices. This report provides a rating system for representing the security health of enterprises.
Biased Support Vector Machine For Relevance Feedback In Image Retrieval, Steven Hoi, Chi-Hang Chan, Kaizhu Huang, Michael R. Lyu, Irwin King
Biased Support Vector Machine For Relevance Feedback In Image Retrieval, Steven Hoi, Chi-Hang Chan, Kaizhu Huang, Michael R. Lyu, Irwin King
Research Collection School Of Computing and Information Systems
Recently, support vector machines (SVMs) have been engaged on relevance feedback tasks in content-based image retrieval. Typical approaches by SVMs treat the relevance feedback as a strict binary classification problem. However, these approaches do not consider an important issue of relevance feedback, i.e. the unbalanced dataset problem, in which the negative instances largely outnumber the positive instances. For solving this problem, we propose a novel technique to formulate the relevance feedback based on a modified SVM called biased support vector machine (Biased SVM or BSVM). Mathematical formulation and explanations are provided for showing the advantages. Experiments are conducted to evaluate …
An Interactive Learning Environment For A Dynamic Educational Digital Library, Ee Peng Lim, Dion Hoe-Lian Goh, Yin-Leng Theng, Eng-Kai Suen
An Interactive Learning Environment For A Dynamic Educational Digital Library, Ee Peng Lim, Dion Hoe-Lian Goh, Yin-Leng Theng, Eng-Kai Suen
Research Collection School Of Computing and Information Systems
GeogDL is a digital library of geography examination resources designed to assist students in preparing for a national geography examination in Singapore. We describe an interactive learning environment built into GeogDL that consists of four major components. The practice and review module allows students to attempt individual examination questions, the mock exam provides a simulation of the actual geography examination, the trends analysis tool provides an overview of the types of questions asked in previous examinations, while the contributions module allows students and teachers to create and share knowledge within the digital library.
Notes On Equilibria In Symmetric Games, Shih-Fen Cheng, Daniel M. Reeves, Yevgeniy Vorobeychik, Michael P. Wellman
Notes On Equilibria In Symmetric Games, Shih-Fen Cheng, Daniel M. Reeves, Yevgeniy Vorobeychik, Michael P. Wellman
Research Collection School Of Computing and Information Systems
In a symmetric game, every player is identical with respect to the game rules. We show that a symmetric 2strategy game must have a pure-strategy Nash equilibrium. We also discuss Nash’s original paper and its generalized notion of symmetry in games. As a special case of Nash’s theorem, any finite symmetric game has a symmetric Nash equilibrium. Furthermore, symmetric infinite games with compact, convex strategy spaces and continuous, quasiconcave utility functions have symmetric pure-strategy Nash equilibria. Finally, we discuss how to exploit symmetry for more efficient methods of finding Nash equilibria.
A Support-Ordered Trie For Fast Frequent Itemset Discovery, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng
A Support-Ordered Trie For Fast Frequent Itemset Discovery, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng
Research Collection School Of Computing and Information Systems
The importance of data mining is apparent with the advent of powerful data collection and storage tools; raw data is so abundant that manual analysis is no longer possible. Unfortunately, data mining problems are difficult to solve and this prompted the introduction of several novel data structures to improve mining efficiency. Here, we critically examine existing preprocessing data structures used in association rule mining for enhancing performance in an attempt to understand their strengths and weaknesses. Our analyses culminate in a practical structure called the SOTrielT (support-ordered trie itemset) and two synergistic algorithms to accompany it for the fast discovery …
Comparison Of Discrete Singular Convolution And Generalised Differential Quadrature For The Vibration Analysis Of Rectangular Plates, C. H. W. Ng, Yibao Zhao, G. W. Wei
Comparison Of Discrete Singular Convolution And Generalised Differential Quadrature For The Vibration Analysis Of Rectangular Plates, C. H. W. Ng, Yibao Zhao, G. W. Wei
Research Collection Lee Kong Chian School Of Business
This paper presents a comprehensive comparison study between the discrete singular convolution (DSC) and the well-known global method of generalized differential quadrature (GDQ) for vibration analysis so as to enhance the understanding of the DSC algorithm. The DSC method is implemented through Lagrange's delta sequence kernel (DSC-LK), which utilizes local Lagrange polynomials to calculate weighting coefficients, whereas, the GDQ requires global ones. Moreover, it is shown that the treatments of boundary conditions and the use of grid systems are different in the two methods. Comparison study is carried out on 21 rectangular plates of different combinations of simply supported (S), …
Proprietary And Open Systems Adoption In E-Procurement: A Risk-Augmented Transactions Cost Perspective, Robert J. Kauffman, Hamid Mohtadi
Proprietary And Open Systems Adoption In E-Procurement: A Risk-Augmented Transactions Cost Perspective, Robert J. Kauffman, Hamid Mohtadi
Research Collection School Of Computing and Information Systems
We present an economic model that enables the study of incentives for business-to-business (B2B) e-procurement systems investments that permit inventory coordination and improved operational control. We focus on the information technology adoption behavior of firms in the presence of transaction costs, agency costs and information uncertainty. We conclude that it is appropriate to rethink the prior theory and develop an extended transaction-cost theory perspective that incorporates the possibility of shocks. We distinguish among three kinds of B2B e-procurement systems platforms. Proprietary platform procurement systems involve traditional electronic data interchange (EDI) technologies. Open platform procurement systems are associated with e-market Web …
Cryptanalysis Of Two Anonymous Buyer-Seller Watermarking Protocols And An Improvement For True Anonymity, Bok-Min Goi, Raphael C. W. Phan, Yanjiang Yang, Feng Bao, Robert H. Deng, M. U. Siddiqi
Cryptanalysis Of Two Anonymous Buyer-Seller Watermarking Protocols And An Improvement For True Anonymity, Bok-Min Goi, Raphael C. W. Phan, Yanjiang Yang, Feng Bao, Robert H. Deng, M. U. Siddiqi
Research Collection School Of Computing and Information Systems
By combining techniques of watermarking and fingerprinting, a sound buyer-seller watermarking protocol can address the issue of copyright protection in e-commerce. In this paper, we analyze the security of two recent anonymous buyer-seller watermarking protocols proposed by Ju et. al and Choi et. al respectively, and prove that they do not provide the features and security as claimed. In particular, we show that i) the commutative cryptosystem used in Choi et. als protocol fails to prevent the watermark certification authority (WCA) from discovering the watermark (fingerprint) chosen by the buyer; ii) for both protocols, the seller can discover the watermark …
A Rate-Distortion Framework For Information-Theoretic Mobility Management, Abhishek Roy, Archan Misra, Sajal K. Das
A Rate-Distortion Framework For Information-Theoretic Mobility Management, Abhishek Roy, Archan Misra, Sajal K. Das
Research Collection School Of Computing and Information Systems
A practical information theoretic framework is developed for studying the optimal tradeoff between location update and paging costs in cellular networks. The framework envisions the quantization of location information into a registration area (RA) level granularity, followed by the use of an entropy-coding technique to decrease the location update rate. The rate distortion theory of the lossy quantization is identified as an appropriate measure for capturing the optimal tradeoff between a mobile's update rate and its location uncertainty. Based on LZ-78 compression, two different RA-level location update algorithms (RA-LeZi and LeZi-RA) have been developed, both of which asymptotically approach this …
Tournament Versus Fitness Uniform Selection, Shane Legg, Marcus Hutter, Akshat Kumar
Tournament Versus Fitness Uniform Selection, Shane Legg, Marcus Hutter, Akshat Kumar
Research Collection School Of Computing and Information Systems
In evolutionary algorithms a critical parameter that must be tuned is that of selection pressure. If it is set too low then the rate of convergence towards the optimum is likely to be slow. Alternatively if the selection pressure is set too high the system is likely to become stuck in a local optimum due to a loss of diversity in the population. The recent Fitness Uniform Selection Scheme (FUSS) is a conceptually simple but somewhat radical approach to addressing this problem - rather than biasing the selection towards higher fitness, FUSS biases selection towards sparsely populated fitness levels. In …
Steganographic Schemes For File System And B-Tree, Hwee Hwa Pang, Kian-Lee Tan, Xuan Zhou
Steganographic Schemes For File System And B-Tree, Hwee Hwa Pang, Kian-Lee Tan, Xuan Zhou
Research Collection School Of Computing and Information Systems
While user access control and encryption can protect valuable data from passive observers, these techniques leave visible ciphertexts that are likely to alert an active adversary to the existence of the data. We introduce StegFD, a steganographic file driver that securely hides user-selected files in a file system so that, without the corresponding access keys, an attacker would not be able to deduce their existence. Unlike other steganographic schemes proposed previously, our construction satisfies the prerequisites of a practical file system in ensuring the integrity of the files and maintaining efficient space utilization. We also propose two schemes for implementing …
Modified Art 2a Growing Network Capable Of Generating A Fixed Number Of Nodes, Ji He, Ah-Hwee Tan, Chew-Lim Tan
Modified Art 2a Growing Network Capable Of Generating A Fixed Number Of Nodes, Ji He, Ah-Hwee Tan, Chew-Lim Tan
Research Collection School Of Computing and Information Systems
This paper introduces the Adaptive Resonance Theory under Constraint (ART-C 2A) learning paradigm based on ART 2A, which is capable of generating a user-defined number of recognition nodes through online estimation of an appropriate vigilance threshold. Empirical experiments compare the cluster validity and the learning efficiency of ART-C 2A with those of ART 2A, as well as three closely related clustering methods, namely online K-Means, batch K-Means, and SOM, in a quantitative manner. Besides retaining the online cluster creation capability of ART 2A, ART-C 2A gives the alternative clustering solution, which allows a direct control on the number of output …
Web Image Learning For Searching Semantic Concepts In Image Databases, Steven Hoi, Michael R. Lyu
Web Image Learning For Searching Semantic Concepts In Image Databases, Steven Hoi, Michael R. Lyu
Research Collection School Of Computing and Information Systems
Without textual descriptions or label information of images, searching semantic concepts in image databases is still a very challenging task. While automatic annotation techniques are yet a long way off, we can seek other alternative techniques to solve this difficult issue. In this paper, we propose to learn Web images for searching the semantic concepts in large image databases. To formulate effective algorithms, we suggest to engage the support vector machines for attacking the problem. We evaluate our algorithm in a large image database and demonstrate the preliminary yet promising results.
Toolglasses, Marking Menus, And Hotkeys: A Comparison Of One And Two-Handed Command Selection Techniques, Daniel L. Odell, Richard C. Davis, Andrew Smith, Paul K. Wright
Toolglasses, Marking Menus, And Hotkeys: A Comparison Of One And Two-Handed Command Selection Techniques, Daniel L. Odell, Richard C. Davis, Andrew Smith, Paul K. Wright
Research Collection School Of Computing and Information Systems
This paper introduces a new input technique, bimanual marking menus, and compares its performance with five other techniques: static toolbars, hotkeys, grouped hotkeys, marking menus, and toolglasses. The study builds on previous work by setting the comparison in a commonly encountered task, shape drawing. In this context, grouped hotkeys and bimanual marking menus were found to be the fastest. Subjectively, the most pre-ferred input method was bimanual marking menus. Toolglass performance was unexpectedly slow, which hints at the importance of low-level toolglass imple-mentation choices.
Power Adaptation Based Optimization For Energy Efficient Reliable Wireless Paths, Suman Banerjee, Archan Misra
Power Adaptation Based Optimization For Energy Efficient Reliable Wireless Paths, Suman Banerjee, Archan Misra
Research Collection School Of Computing and Information Systems
We define a transmission power adaptation-based routing technique that finds optimal paths for minimum energy reliable data transfer in multi-hop wireless networks. This optimal choice of the transmission power depends on the link distance between the two nodes and the channel characteristics. Typical energy efficient routing techniques use a transmission power such that the received signal power at the destination minimally exceeds a desired threshold signal strength level. In this paper we argue that such a choice of the transmission power does not always lead to optimal energy routes, since it does not consider differences in the receiver noise levels.We …
Multi-Period Multi-Dimensional Knapsack Problem And Its Application To Available-To-Promise, Hoong Chuin Lau, M. K. Lim
Multi-Period Multi-Dimensional Knapsack Problem And Its Application To Available-To-Promise, Hoong Chuin Lau, M. K. Lim
Research Collection School Of Computing and Information Systems
This paper is motivated by a recent trend in logistics scheduling, called Available-to-Promise. We model this problem as the multi-period multi-dimensional knapsack problem. We provide some properties for a special case of a single-dimensional problem. Based on insights obtained from these properties, we propose a two-phase heuristics for solving the multi-dimensional problem. We also propose a novel time-based ant colony optimization algorithm. The quality of the solutions generated is verified through experiments, where we demonstrate that the computational time is superior compared with integer programming to achieve solutions that are within a small percentage of the upper bounds.
On Leverage In A Stochastic Volatility Model, Jun Yu
On Leverage In A Stochastic Volatility Model, Jun Yu
Research Collection School Of Economics
This paper is concerned with specification for modelling financial leverage effect in the context of stochastic volatility (SV) models. Two alternative specifications co-exist in the literature. One is the Euler approximation to the well known continuous time SV model with leverage effect and the other is the discrete time SV model of Jacquier, Polson and Rossi (2004, Journal of Econometrics, forthcoming). Using a Gaussian nonlinear state space form with uncorrelated measurement and transition errors, I show that it is easy to interpret the leverage effect in the conventional model whereas it is not clear how to obtain the leverage effect …
A Cost-Effective Critical Path Approach For Service Priority Optimization In The Grid Computing Economy, Mei Lin, Zhangxi Lin
A Cost-Effective Critical Path Approach For Service Priority Optimization In The Grid Computing Economy, Mei Lin, Zhangxi Lin
Research Collection School Of Computing and Information Systems
The advancement in the utilization and technologiesof the Internet has led to the rapid growth of gridcomputing; and the perpetuating demand for gridcomputing resources calls for an incentive-compatible solution to the imminent QoS problem. This paper examines the optimal service priority selection problem that a grid computing network user will confront. We model grid services for a multi-subtask request as a prioritized PERT graph and prove that the localized conditional critical path, which is based on the cost-minimizin gpriority selection for each node, sets the lower bound for the length of cost-effective critical path that commits the optimal solution. We …
Suppression Of Polarization Switching In Birefringent Antiresonant Reflecting Optical Waveguide Vertical-Cavity Surface-Emitting Lasers, N. S. Chen, S. F. Yu, Chyng Wen Tee
Suppression Of Polarization Switching In Birefringent Antiresonant Reflecting Optical Waveguide Vertical-Cavity Surface-Emitting Lasers, N. S. Chen, S. F. Yu, Chyng Wen Tee
Research Collection Lee Kong Chian School Of Business
Influence of birefringence on the multimode operation of antiresonant reflecting optical waveguide (ARROW) vertical-cavity surface-emitting lasers (VCSELs) is analyzed. It can be shown that polarization switching is mainly due to thermal lensing effects. Hence, a new design rule is proposed to optimize the dimensions of ARROW for the suppression of polarization switching. Using the optimized design, the maximum single-polarization output power of VCSELs can be tripled. In addition, it is shown that the performance of the optimized ARROW VCSELs will not be deteriorated by the uncertainty of birefringence.
Phoneme-Based Transliteration Of Foreign Names For Oov Problem, Wei Gao, Kam-Fai Wong, Wai Lam
Phoneme-Based Transliteration Of Foreign Names For Oov Problem, Wei Gao, Kam-Fai Wong, Wai Lam
Research Collection School Of Computing and Information Systems
A proper noun dictionary is never complete rendering name translation from English to Chinese ineffective. One way to solve this problem is not to rely on a dictionary alone but to adopt automatic translation according to pronunciation similarities, i.e. to map phonemes comprising an English name to the phonetic representations of the corresponding Chinese name. This process is called transliteration. We present a statistical transliteration method. An efficient algorithm for aligning phoneme chunks is described. Unlike rule-based approaches, our method is data-driven. Compared to source-channel based statistical approaches, we adopt a direct transliteration model, i.e. the direction of probabilistic estimation …
Prediction Of Rna-Binding Proteins From Primary Sequence By A Support Vector Machine Approach., Lian Yi Han, Cong Zhong Cai, Siaw Ling Lo, Maxey Chung, Yu Zong Chen
Prediction Of Rna-Binding Proteins From Primary Sequence By A Support Vector Machine Approach., Lian Yi Han, Cong Zhong Cai, Siaw Ling Lo, Maxey Chung, Yu Zong Chen
Research Collection School Of Computing and Information Systems
Elucidation of the interaction of proteins with different molecules is of significance in the understanding of cellular processes. Computational methods have been developed for the prediction of protein-protein interactions. But insufficient attention has been paid to the prediction of protein-RNA interactions, which play central roles in regulating gene expression and certain RNA-mediated enzymatic processes. This work explored the use of a machine learning method, support vector machines (SVM), for the prediction of RNA-binding proteins directly from their primary sequence. Based on the knowledge of known RNA-binding and non-RNA-binding proteins, an SVM system was trained to recognize RNA-binding proteins. A total …
The Evolution Of Research On Information Systems: A Fiftieth Year Survey Of The Literature In Management Science, Rajiv D. Banker, Robert J. Kauffman
The Evolution Of Research On Information Systems: A Fiftieth Year Survey Of The Literature In Management Science, Rajiv D. Banker, Robert J. Kauffman
Research Collection School Of Computing and Information Systems
The development of the information systems (IS) literature in Management Science during the past 50 years reflects the inception, growth, and maturation of several different research streams. The five research streams we identify incorporate different definitions of the managerial problems that relate to IS, the alternate theoretical perspectives and different methodological paradigms to study them, and the levels of the organization at which their primary results impact managerial practice. The decision support and design science research stream studies the application of computers in decision support, control, and managerial decision making. The value of information research stream reflects relationships established based …
Tool Support For Model Based Architectural Design For Automotive Control Systems, Kevin Steppe
Tool Support For Model Based Architectural Design For Automotive Control Systems, Kevin Steppe
Research Collection School Of Computing and Information Systems
In conjunction with Ford Motor Company, we built a tool to support multilevel architectural design. The tool, called Synergy, allows Ford to visually design architectures of vehicle control components. The components are imported from existing Simulink models; then the tool automatically generates a detailed view showing all required connections and ports. The resulting model is exported to Simulink for further analysis. In this paper we describe the conceptual and technical challenges encountered in building Synergy and our design choices for solving them.
Security Analysis Of Some Proxy Signature, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng
Security Analysis Of Some Proxy Signature, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng
Research Collection School Of Computing and Information Systems
A proxy signature scheme allows an entity to delegate his/her signing capability to another entity in such a way that the latter can sign messages on behalf of the former. Such schemes have been suggested for use in a number of applications, particularly in distributed computing where delegation of rights is quite common. Followed by the first schemes introduced by Mambo, Usuda and Okamoto in 1996, a number of new schemes and improvements have been proposed. In this paper, we present a security analysis of four such schemes newly proposed. By successfully identifying several interesting forgery attacks, we show that …
Authenticating Query Results In Edge Computing, Hwee Hwa Pang, Kian-Lee Tan
Authenticating Query Results In Edge Computing, Hwee Hwa Pang, Kian-Lee Tan
Research Collection School Of Computing and Information Systems
Edge computing pushes application logic and the underlying data to the edge of the network, with the aim of improving availability and scalability. As the edge servers are not necessarily secure, there must be provisions for validating their outputs. This paper proposes a mechanism that creates a verification object (VO) for checking the integrity of each query result produced by an edge server - that values in the result tuples are not tampered with, and that no spurious tuples are introduced. The primary advantages of our proposed mechanism are that the VO is independent of the database size, and that …
Clash: A Protocol For Internet-Scale Utility-Oriented Distributed Computing, Archan Misra, Paul Castro, Jinwon Lee
Clash: A Protocol For Internet-Scale Utility-Oriented Distributed Computing, Archan Misra, Paul Castro, Jinwon Lee
Research Collection School Of Computing and Information Systems
Distributed hash table (DHT) overlay networks offer an efficient and robust technique for wire-area data storage and queries. Workload from real applications that use DHT networks will likely exhibit significant skews that can result in bottlenecks and failures that limit the overall scalability of the DHT approach. We present the content and load-aware scalable hashing (CLASH) protocol that can enhance the load distribution behavior of a DHT. CLASH relies on a variable-length identifier key scheme, where the length of any individual key is a function of load. CLASH uses variable-length keys to cluster content-related objects on single nodes to achieve …
Group Nearest Neighbor Queries, Dimitris Papadias, Qiongmao Shen, Yufei Tao, Kyriakos Mouratidis
Group Nearest Neighbor Queries, Dimitris Papadias, Qiongmao Shen, Yufei Tao, Kyriakos Mouratidis
Research Collection School Of Computing and Information Systems
Given two sets of points P and Q, a group nearest neighbor (GNN) query retrieves the point(s) of P with the smallest sum of distances to all points in Q. Consider, for instance, three users at locations q1 , q2 and q3 that want to find a meeting point (e.g., a restaurant); the corresponding query returns the data point p that minimizes the sum of Euclidean distances |pqi| for 1 ≤i ≤3. Assuming that Q fits in memory and P is indexed by an R-tree, we propose several algorithms for finding the group nearest neighbors efficiently. As a second step, …
Efficient Group Pattern Mining Using Data Summarization, Yida Wang, Ee Peng Lim, San-Yih Hwang
Efficient Group Pattern Mining Using Data Summarization, Yida Wang, Ee Peng Lim, San-Yih Hwang
Research Collection School Of Computing and Information Systems
In group pattern mining, we discover group patterns from a given user movement database based on their spatio-temporal distances. When both the number of users and the logging duration are large, group pattern mining algorithms become very inefficient. In this paper, we therefore propose a spherical location summarization method to reduce the overhead of mining valid 2-groups. In our experiments, we show that our group mining algorithm using summarized data may require much less execution time than that using non-summarized data.
Hiding Data Accesses In Steganographic File System, Xuan Zhou, Hwee Hwa Pang, Kian-Lee Tan
Hiding Data Accesses In Steganographic File System, Xuan Zhou, Hwee Hwa Pang, Kian-Lee Tan
Research Collection School Of Computing and Information Systems
To support ubiquitous computing, the underlying data have to be persistent and available anywhere-anytime. The data thus have to migrate from devices local to individual computers, to shared storage volumes that are accessible over open network. This potentially exposes the data to heightened security risks. We propose two mechanisms, in the context of a steganographic file system, to mitigate the risk of attacks initiated through analyzing data accesses from user applications. The first mechanism is intended to counter attempts to locate data through updates in between snapshots - in short, update analysis. The second mechanism prevents traffic analysis - identifying …