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Full-Text Articles in Physical Sciences and Mathematics
Privacy-Preserving Arbitrary Geometric Range Query In Mobile Internet Of Vehicles, Yinbin Miao, Lin Song, Xinghua Li, Hongwei Li, Kim-Kwang Raymond Choo, Robert H. Deng
Privacy-Preserving Arbitrary Geometric Range Query In Mobile Internet Of Vehicles, Yinbin Miao, Lin Song, Xinghua Li, Hongwei Li, Kim-Kwang Raymond Choo, Robert H. Deng
Research Collection School Of Computing and Information Systems
The mobile Internet of Vehicles (IoVs) has great potential for intelligent transportation, and creates spatial data query demands to realize the value of data. Outsourcing spatial data to a cloud server eliminates the need for local computation and storage, but it leads to data security and privacy threats caused by untrusted third-parties. Existing privacy-preserving spatial range query solutions based on Homomorphic Encryption (HE) have been developed to increase security. However, in the single server model, the private key is held by the query user, which incurs high computation and communication burdens on query users due to multiple rounds of interactions. …
Annapurna: An Automated Smartwatch-Based Eating Detection And Food Journaling System, Sougata Sen, Vigneshwaran Subbaraju, Archan Misra, Rajesh Krishna Balan, Youngki Lee
Annapurna: An Automated Smartwatch-Based Eating Detection And Food Journaling System, Sougata Sen, Vigneshwaran Subbaraju, Archan Misra, Rajesh Krishna Balan, Youngki Lee
Research Collection School Of Computing and Information Systems
Maintaining a food journal can allow an individual to monitor eating habits, including unhealthy eating sessions, food items causing severe reactions, or portion size related information. However, manually maintaining a food journal can be burdensome. In this paper, we explore the vision of a pervasive, automated, completely unobtrusive, food journaling system using a commodity smartwatch. We present a prototype system — Annapurna— which is composed of three key components: (a) a smartwatch-based gesture recognizer that can robustly identify eating-specific gestures occurring anywhere, (b) a smartwatch-based image captor that obtains a small set of relevant images (containing views of the food …
Toward Accurate Network Delay Measurement On Android Phones, Weichao Li, Daoyuan Wu, Rocky K. C. Chang, Ricky K. P. Mok
Toward Accurate Network Delay Measurement On Android Phones, Weichao Li, Daoyuan Wu, Rocky K. C. Chang, Ricky K. P. Mok
Research Collection School Of Computing and Information Systems
Measuring and understanding the performance of mobile networks is becoming very important for end users and operators. Despite the availability of many measurement apps, their measurement accuracy has not received sufficient scrutiny. In this paper, we appraise the accuracy of smartphone-based network performance measurement using the Android platform and the network round-trip time (RTT) as the metric. We show that two of the most popular measurement apps-Ookla Speedtest and MobiPerf-have their RTT measurements inflated. We build three test apps that cover three common measurement methods and evaluate them in a testbed. We overcome the main challenge of obtaining a complete …
Where Am I? Characterizing And Improving The Localization Performance Of Off-The-Shelf Mobile Devices Through Cooperation, Huiguang Liang, Hyong S. Kim, Hwee-Pink Tan, Wai-Leong Yeow
Where Am I? Characterizing And Improving The Localization Performance Of Off-The-Shelf Mobile Devices Through Cooperation, Huiguang Liang, Hyong S. Kim, Hwee-Pink Tan, Wai-Leong Yeow
Research Collection School Of Computing and Information Systems
We are increasingly reliant on cellular data services for many types of day-to-day activities, from hailing a cab, to searching for nearby restaurants. Geo-location has become a ubiquitous feature that underpins the functionality of such applications. Network operators can also benefit from accurate mobile terminal localization in order to quickly detect and identify location-related network performance issues, such as coverage holes and congestion, based on mobile measurements. Current implementations of mobile localization on the wildly-popular Android platform depend on either the Global Positioning System (GPS), Android's Network Location Provider (NLP), or a combination of both. In this paper, we extensively …
Livelabs: Building An In-Situ Real-Time Mobile Experimentation Testbed, Rajesh Krishna Balan, Archan Misra, Youngki Lee
Livelabs: Building An In-Situ Real-Time Mobile Experimentation Testbed, Rajesh Krishna Balan, Archan Misra, Youngki Lee
Research Collection School Of Computing and Information Systems
We present LiveLabs, a mobile experimentation testbed that is currently deployed across our university campus with further deployments at a large shopping mall, a commercial airport, and a resort island soon to follow. The key goal of LiveLabs is to allow in-situ real-time experimentation of mobile applications and services that require context-specific triggers with real participants on their actual smart phones. We describe how LiveLabs works, and then explain the novel R&D required to realise it. We end with a descriptionof the current LiveLabs status (> 700 active participants to date) as well as present some key lessons learned.
Barometric Phone Sensors: More Hype Than Hope!, Kartik Muralidharan, Azeem Javed Khan, Archan Misra, Rajesh Krishna Balan, Sharad Agarwal
Barometric Phone Sensors: More Hype Than Hope!, Kartik Muralidharan, Azeem Javed Khan, Archan Misra, Rajesh Krishna Balan, Sharad Agarwal
Research Collection School Of Computing and Information Systems
The inclusion of the barometer sensor in smartphones signaled an opportunity for aiding indoor localization efforts. In this paper, we therefore investigate a possible use of the barometer sensor for detecting vertically oriented activities. We start by showing the accuracies of various commodity measurement devices and the challenges they bring forth. We then show how to use the barometer values to build a predictor that can detect floor changes and the mode (elevator, escalator, or stairs) used to change floors with nearly 100% accuracy. We validate these properties with data collected using 3 different measurement devices from 7 different buildings. …
A Robust Smart Card-Based Anonymous User Authentication Protocol For Wireless Communications, Fengton Wen, Willy Susilo, Guomin Yang
A Robust Smart Card-Based Anonymous User Authentication Protocol For Wireless Communications, Fengton Wen, Willy Susilo, Guomin Yang
Research Collection School Of Computing and Information Systems
Anonymous user authentication is an important but challenging task for wireless communications. In a recent paper, Das proposed a smart cardï based anonymous user authentication protocol for wireless communications. The scheme can protect user privacy and is believed to be secure against a range of network attacks even if the secret information stored in the smart card is compromised. In this paper, we reanalyze the security of Das' scheme, and show that the scheme is in fact insecure against impersonation attacks. We then propose a new smart cardï based anonymous user authentication protocol for wireless communications. Compared with the existing …
A Distributed Spatial Index For Error-Prone Wireless Data Broadcast, Baihua Zheng, Wang-Chien Lee, Ken C. K. Lee, Dik Lun Lee, Min Shao
A Distributed Spatial Index For Error-Prone Wireless Data Broadcast, Baihua Zheng, Wang-Chien Lee, Ken C. K. Lee, Dik Lun Lee, Min Shao
Research Collection School Of Computing and Information Systems
Information is valuable to users when it is available not only at the right time but also at the right place. To support efficient location-based data access in wireless data broadcast systems, a distributed spatial index (called DSI) is presented in this paper. DSI is highly efficient because it has a linear yet fully distributed structure that naturally shares links in different search paths. DSI is very resilient to the error-prone wireless communication environment because interrupted search operations based on DSI can be resumed easily. It supports search algorithms for classical location-based queries such as window queries and kNN queries …
Mferio: The Design And Evaluation Of A Peer-To-Peer Mobile Payment System, Rajesh Krishna Balan, Narayanasamy Ramasubbu, Komsit Prakobphol, Nicolas Christin, Jason Hong
Mferio: The Design And Evaluation Of A Peer-To-Peer Mobile Payment System, Rajesh Krishna Balan, Narayanasamy Ramasubbu, Komsit Prakobphol, Nicolas Christin, Jason Hong
Research Collection School Of Computing and Information Systems
In this paper, we present the design and evaluation of a near-field communication-based mobile p2p payment application, called mFe-rio, that is designed to replace cash-based transactions. We first identify design criteria that payment systems should satisfy and then explain how mFerio, relative to those criteria, improves on the limitations of cash-based systems. We next describe mFerio's implementation and user interface design, focusing on the balance between usability and security. Finally, we present the results of a two-phase user study, involving a total of 104 people, that shows that mFerio has low cognitive load and is also fast, accurate, and easy …
The Digital Wallet: Opportunities And Prototypes, Rajesh Krishna Balan, Narayanasamy Ramasubbu
The Digital Wallet: Opportunities And Prototypes, Rajesh Krishna Balan, Narayanasamy Ramasubbu
Research Collection School Of Computing and Information Systems
Example digital wallet applications support secure P2P mobile cash transactions and alleviate point-of-sale confusion for consumers using multiple payment, discount, and loyalty cards.
Simplifying Cyber Foraging For Mobile Devices, Rajesh Krishna Balan, Darren Gergle, Mahadev Satyanarayanan, James Herbsleb
Simplifying Cyber Foraging For Mobile Devices, Rajesh Krishna Balan, Darren Gergle, Mahadev Satyanarayanan, James Herbsleb
Research Collection School Of Computing and Information Systems
Cyber foraging is the transient and opportunistic use of compute servers by mobile devices. The short market life of such devices makes rapid modification of applications for remote execution an important problem. We describe a solution that combines a "little language" for cyber foraging with an adaptive runtime system. We report results from a user study showing that even novice developers are able to successfully modify large, unfamiliar applications in just a few hours. We also show that the quality of novice-modified and expert-modified applications are comparable in most cases.
An Energy-Efficient And Access Latency Optimized Indexing Scheme For Wireless Data Broadcast, Yuxia Yao, Xueyan Tang, Ee Peng Lim, Aixin Sun
An Energy-Efficient And Access Latency Optimized Indexing Scheme For Wireless Data Broadcast, Yuxia Yao, Xueyan Tang, Ee Peng Lim, Aixin Sun
Research Collection School Of Computing and Information Systems
Data broadcast is an attractive data dissemination method in mobile environments. To improve energy efficiency, existing air indexing schemes for data broadcast have focused on reducing tuning time only, i.e., the duration that a mobile client stays active in data accesses. On the other hand, existing broadcast scheduling schemes have aimed at reducing access latency through nonflat data broadcast to improve responsiveness only. Not much work has addressed the energy efficiency and responsiveness issues concurrently. This paper proposes an energy-efficient indexing scheme called MHash that optimizes tuning time and access latency in an integrated fashion. MHash reduces tuning time by …
Sgpm: Static Group Pattern Mining Using Apriori-Like Sliding Window, John Goh, David Taniar, Ee Peng Lim
Sgpm: Static Group Pattern Mining Using Apriori-Like Sliding Window, John Goh, David Taniar, Ee Peng Lim
Research Collection School Of Computing and Information Systems
Mobile user data mining is a field that focuses on extracting interesting pattern and knowledge out from data generated by mobile users. Group pattern is a type of mobile user data mining method. In group pattern mining, group patterns from a given user movement database is found based on spatio-temporal distances. In this paper, we propose an improvement of efficiency using area method for locating mobile users and using sliding window for static group pattern mining. This reduces the complexity of valid group pattern mining problem. We support the use of static method, which uses areas and sliding windows instead …
Tosa: A Near-Optimal Scheduling Algorithm For Multi-Channel Data Broadcast, Baihua Zheng, Xia Xu, Xing Jin, Dik Lun Lee
Tosa: A Near-Optimal Scheduling Algorithm For Multi-Channel Data Broadcast, Baihua Zheng, Xia Xu, Xing Jin, Dik Lun Lee
Research Collection School Of Computing and Information Systems
Wireless broadcast is very suitable for delivering information to a large user population. In this paper, we concentrate on data allocation methods for multiple broadcast channels. To the best of our knowledge, this is the first allocation model that takes into the consideration of items' access frequencies, items' lengths. and bandwidth of different channels. We first derive the optimal average expected delay for multiple channels for the general case where data access frequencies, data sizes, and channel bandwidths can all be non-uniform. Second, we develop TOSA, a multi-channel allocation method that does not assume a uniform broadcast schedule for data …
Making The Key Agreement Protocol In Mobile Ad Hoc Network More Efficient, Gang Yao, Kui Ren, Feng Bao, Robert H. Deng, Dengguo Feng
Making The Key Agreement Protocol In Mobile Ad Hoc Network More Efficient, Gang Yao, Kui Ren, Feng Bao, Robert H. Deng, Dengguo Feng
Research Collection School Of Computing and Information Systems
Mobile ad hoc networks offer convenient infrastructureless communications over the shared wireless channel. However, the nature of mobile ad hoc networks makes them vulnerable to security attacks, such as passive eavesdropping over the wireless channel and denial of service attacks by malicious nodes. To ensure the security, several cryptography protocols are implemented. Due to the resource scarcity in mobile ad hoc networks, the protocols must be communication efficient and need as less computational power as possible. Broadcast communication is an important operation for many application in mobile ad hoc networks. To securely broadcast a message, all the members in the …
Cache Invalidation And Replacement Strategies For Location-Dependent Data In Mobile Environments, Baihua Zheng, Jianliang Xu, Dik Lun Lee
Cache Invalidation And Replacement Strategies For Location-Dependent Data In Mobile Environments, Baihua Zheng, Jianliang Xu, Dik Lun Lee
Research Collection School Of Computing and Information Systems
Mobile location-dependent information services (LDISs) have become increasingly popular in recent years. However, data caching strategies for LDISs have thus far received little attention. In this paper, we study the issues of cache invalidation and cache replacement for location-dependent data under a geometric location model. We introduce a new performance criterion, called caching efficiency, and propose a generic method for location-dependent cache invalidation strategies. In addition, two cache replacement policies, PA and PAID, are proposed. Unlike the conventional replacement policies, PA and PAID take into consideration the valid scope area of a data value. We conduct a series of simulation …
Tcp Hack: Tcp Header Checksum Option To Improve Performance Over Lossy Links, Rajesh Krishna Balan, Boon Peng Lee, Renjish Kumar, Jacob Lillykutty, Winston Seah, A. L. Ananda
Tcp Hack: Tcp Header Checksum Option To Improve Performance Over Lossy Links, Rajesh Krishna Balan, Boon Peng Lee, Renjish Kumar, Jacob Lillykutty, Winston Seah, A. L. Ananda
Research Collection School Of Computing and Information Systems
Wireless networks have become increasingly common and an increasing number of devices are communicating with each other over lossy links. Unfortunately, TCP performs poorly over lossy links as it is unable to differentiate the loss due to packet corruption from that due to congestion. We present an extension to TCP which enables TCP to distinguish packet corruption from congestion in lossy environments resulting in improved performance. We refer to this extension as the HeAder ChecKsum option (HACK). We implemented our algorithm in the Linux kernel and performed various tests to determine its effectiveness. Our results have shown that HACK performs …
Notepals: Lightweight Note Sharing By The Group, For The Group, Richard C. Davis, James A. Landay, Victor Chen, Jonathan Huang, Rebecca B. Lee, Francis Li, James Lin, Charles B. Morrey, Morgan N. Price, Bill N. Schilit
Notepals: Lightweight Note Sharing By The Group, For The Group, Richard C. Davis, James A. Landay, Victor Chen, Jonathan Huang, Rebecca B. Lee, Francis Li, James Lin, Charles B. Morrey, Morgan N. Price, Bill N. Schilit
Research Collection School Of Computing and Information Systems
NotePals is a lightweight note sharing system that gives group members easy access to each others experiences through their personal notes. The system allows notes taken by group members in any context to be uploaded to a shared repository. Group members view these notes with browsers that allow them to retrieve all notes taken in a given context or to access notes from other related notes or documents. This is possible because NotePals records the context in which each note is created (e.g., its author, subject, and creation time). The system is lightweight because it fits easily into group members …
A Framework For Sharing Handwritten Notes, Richard C. Davis, James Lin, Jason A. Brotherton, James A. Landay, Morgan N. Price, Bill N. Schilit
A Framework For Sharing Handwritten Notes, Richard C. Davis, James Lin, Jason A. Brotherton, James A. Landay, Morgan N. Price, Bill N. Schilit
Research Collection School Of Computing and Information Systems
NotePals is an ink-based, collaborative note taking application that runs on personal digital assistants (PDAs). Meeting participants write notes in their own handwriting on a PDA. These notes are shared with other participants by synchronizing later with a shared note repository that can be viewed using a desktop-based web browser. NotePals is distinguished by its lightweight process, interface, and hardware. This demonstration illustrates the design of two different NotePals clients and our web-based note browser.
Notepals: Sharing And Synchronizing Handwritten Notes With Multimedia Documents, James A. Landay, Richard C. Davis, Victor Chen, Jonathan Huang, Rebecca B. Lee, Francis Li, James Lin, Charles B. Morrey, Ben Schleimer
Notepals: Sharing And Synchronizing Handwritten Notes With Multimedia Documents, James A. Landay, Richard C. Davis, Victor Chen, Jonathan Huang, Rebecca B. Lee, Francis Li, James Lin, Charles B. Morrey, Ben Schleimer
Research Collection School Of Computing and Information Systems
NotePals is an ink-based, collaborative note taking application that runs on personal digital assistants (PDAs). Meeting participants write notes in their own handwriting on a PDA. These notes are shared with other participants by synchronizing later with a shared note repository that can be viewed using a desktop-based web browser. NotePals is distinguished by its lightweight process, interface, and hardware. This demonstration illustrates the design of two different NotePals clients and our web-based note browser.