Vol. 7, No. 1, Mar. 2011
Mohamed Kamal JBIRA, Munir AHMED
Vol. 7, No. 1, pp. 1-16, Mar. 2011
Keywords: Traffic congestion, Hybrid Model, Optimisation Method
Show / Hide AbstractWith the increasing number of vehicles in use in our daily life and the rise of traffic congestion problems, many methods and models have been developed for real time optimisation of traffic lights. Nevertheless, most methods which consider real time physical queue sizes of vehicles waiting for green lights overestimate the optimal cycle length for such real traffic control. This paper deals with the development of a generic hybrid model describing both physical traffic flows and control of signalised intersections. The firing times assigned to the transitions of the control part are considered dynamic and are calculated by a simplified optimisation method. This method is based on splitting green times proportionally to the predicted queue sizes through input links for each new cycle time. The proposed model can be easily translated into a control code for implementation in a real time control system.
Jiehui Chen, Mariam B.Salim, Mitsuji Matsumoto
Vol. 7, No. 1, pp. 17-28, Mar. 2011
Keywords: Mobile Target Tracking, Sensor Network, Clustering, Voronoi Diagram
Show / Hide AbstractDespite the fact that the deployment of sensor networks and target tracking could both be managed by taking full advantage of Voronoi diagrams, very little few have been made in this regard. In this paper, we designed an optimized barrier coverage and an energy-efficient clustering algorithm for forming Vonoroi-based Wireless Sensor Networks(WSN) in which we proposed a mobile target tracking scheme (CTT&MAV) that takes full advantage of Voronoi-diagram boundary to improve detectability. Simulations verified that CTT&MAV outperforms random walk, random waypoint, random direction and Gauss-Markov in terms of both the average hop distance that the mobile target moved before being detected and lower sensor death rate. Moreover, we demonstrate that our results are robust as realistic sensing models and also validate our observations through extensive simulations.
Aries Kusdaryono, Kyung Oh Lee
Vol. 7, No. 1, pp. 29-42, Mar. 2011
Keywords: ad hoc network, Wireless Sensor Networks, Clustering, Routing Protocol
Show / Hide AbstractWireless sensor networks are composed of a large number of sensor nodes with limited energy resources. One critical issue in wireless sensor networks is how to gather sensed information in an energy efficient way, since their energy is limited. The clustering algorithm is a technique used to reduce energy consumption. It can improve the scalability and lifetime of wireless sensor networks. In this paper, we introduce a clustering protocol with mode selection (CPMS) for wireless sensor networks. Our scheme improves the performance of BCDCP (Base Station Controlled Dynamic Clustering Protocol) and BIDRP (Base Station Initiated Dynamic Routing Protocol) routing protocol. In CPMS, the base station constructs clusters and makes the head node with the highest residual energy send data to the base station. Furthermore, we can save the energy of head nodes by using the modes selection method. The simulation results show that CPMS achieves longer lifetime and more data message transmissions than current important clustering protocols in wireless sensor networks.
Mouhamed Abdulla, Yousef R. Shayan
Vol. 7, No. 1, pp. 43-52, Mar. 2011
Keywords: MBWA, IEEE 802.20, Interference, Mobility, Degradation
Show / Hide AbstractWhether it is crosstalk, harmonics, or in-band operation of wireless technologies, interference between a reference system and a host of offenders is virtually unavoidable. In past contributions, a benchmark has been established and considered for coexistence analysis with a number of technologies including FWA, UMTS, and WiMAX. However, the previously presented model does not take into account the mobility factor of the reference node in addition to a number of interdependent requirements regarding the link direction, channel state, data rate and system factors; hence limiting its applicability for the MBWA (IEEE 802.20) standard. Thus, over diverse modes, in this correspondence we analytically derived the greatest aggregate interference level tolerated for high-fidelity transmission tailored specifically for the MBWA standard. Our results, in the form of benchmark indicators, should be of particular interest to peers analyzing and researching RF coexistence scenarios with this new protocol.
Ivy Ong, Hyotaek Lim
Vol. 7, No. 1, pp. 53-62, Mar. 2011
Keywords: iATA Protocol, Load Balancing, Network Monitoring, Storage Network Solution, Write Replication
Show / Hide AbstractWith the steady growth of mobile technology and applications, demand for more storage in mobile devices has also increased. A lightweight block-level protocol, Internet Advanced Technology Attachment (iATA), has been developed to deliver a costeffective storage network solution for mobile devices to obtain more storage. This paper seeks to contribute to designing and implementing Load Balancing (LB), Network Monitoring (NM) and Write Replication (WR) modules to improve the protocol¡¯s scalability and data availability. LB and NM modules are invoked to collect system resources states and current network status at each associate node (server machine). A dynamic weight factor is calculated based on the collected information and sent to a referral server. The referral server is responsible to analyze and allocate the most ideal node with the least weight to serve the client. With this approach, the client can avoid connecting to a heavily loaded node that may cause delays in subsequent in-band I/O operations. Write replication is applied to the remaining nodes through a WR module by utilizing the Unison file synchronization program. A client initially connected to node IP A for write operations will have no hindrances in executing the relevant read operations at node IP B in new connections. In the worst case scenario of a node crashing, data remain recoverable from other functioning nodes. We have conducted several benchmark tests and our results are evaluated and verified in a later section.
Chunye Gong, Jie Liu, Haitao Chen, Jing Xie, Zhenghu Gong
Vol. 7, No. 1, pp. 63-74, Mar. 2011
Keywords: Sweep3D, Neutron Transport, GPU, CUDA
Show / Hide AbstractAs a powerful and flexible processor, the Graphic Processing Unit (GPU) can offer a great faculty in solving many high-performance computing applications. Sweep3D, which simulates a single group time-independent discrete ordinates (Sn) neutron transport deterministically on 3D Cartesian geometry space, represents the key part of a real ASCI application. The wavefront process for parallel computation in Sweep3D limits the concurrent threads on the GPU. In this paper, we present multi-dimensional optimization methods for Sweep3D, which can be efficiently implemented on the finegrained parallel architecture of the GPU. Our results show that the overall performance of Sweep3D on the CPU-GPU hybrid platform can be improved up to 4.38 times as compared to the CPU-based implementation.
Vol. 7, No. 1, pp. 75-84, Mar. 2011
Keywords: Enhanced Pyramid Model, Hamiltonian Cycle, Edge-Disjoint Cycle
Show / Hide AbstractThe enhanced pyramid graph was recently proposed as an interconnection network model in parallel processing for maximizing regularity in pyramid networks. We prove that there are two edge-disjoint Hamiltonian cycles in the enhanced pyramid networks. This investigation demonstrates its superior property in edge fault tolerance. This result is optimal in the sense that the minimum degree of the graph is only four.
Vol. 7, No. 1, pp. 85-92, Mar. 2011
Keywords: Processor Array, Dynamically Reconfigurable Bus, Statically Partitioned Bus, Scaling-Simulation, Polylogarithmic Time Simulation
Show / Hide AbstractThis paper shows an effective partitioning of static global row/column buses for tightly coupled 2D mesh-connected small processor arrays (¡°mesh¡±, for short). With additional O(n/m (n/m + log m)) time slowdown, it enables the mesh of size m¡¿m with static row/column buses to simulate the mesh of the larger size n¡¿n with reconfigurable row/column buses (m ¡Â n). This means that if a problem can be solved in O(T) time by the mesh of size n¡¿n with reconfigurable buses, then the same problem can be solved in O(T n/m (n/m + log m)) time on the mesh of a smaller size m¡¿m without a reconfigurable function. This time-cost is optimal when the relation n ¡Ã m log m holds (e.g., m = n1-¥å for ¥å> 0).
Dynamic Voltage and Frequency Scaling for Power-Constrained Design using Process Voltage and Temperature Sensor CircuitsHaiqing Nan, Kyung Ki Kim, Wei Wang, Ken Choi
Vol. 7, No. 1, pp. 93-102, Mar. 2011
Keywords: PVT Variation sensors, Yield, Voltage Scaling, Frequency Scaling
Show / Hide AbstractIn deeply scaled CMOS technologies, two major non-ideal factors are threatening the survival of the CMOS; i) PVT (process, voltage, and temperature) variations and ii) leakage power consumption. In this paper, we propose a novel postsilicon tuning methodology to scale optimum voltage and frequency ¡°dynamically¡±. The proposed design technique will use our PVT sensor circuits to monitor the variations and based on the monitored variation data, voltage and frequency will be compensated ¡°automatically¡±. During the compensation process, supply voltage is dynamically adjusted to guarantee the minimum total power consumption without violating the frequency requirement. The simulation results show that the proposed technique can reduce the total power by 85% and the static power by 53% on average for the selected ISCAS¡¯85 benchmark circuits with 45 nm CMOS technology compared to the results of the traditional PVT compensation method.
Jun Guo, Joohee Kim
Vol. 7, No. 1, pp. 103-110, Mar. 2011
Keywords: distributed video coding, Wyner-Ziv Coding, Spatial Motion Vector Smoothing, Weighted Vector Median Filter, Side Information
Show / Hide AbstractIn this paper, an adaptive motion vector smoothing scheme based on weighted vector median filtering is proposed in order to eliminate the motion outliers more effectively for improving the quality of side information in frame-based distributed video coding. We use a simple motion vector outlier reliability measure for each block in a motion compensated interpolated frame and apply weighted vector median filtering only to the blocks with unreliable motion vectors. Simulation results show that the proposed adaptive motion vector smoothing algorithm improves the quality of the side information significantly while maintaining low complexity at the encoder in frame-based distributed video coding.
Divyan M. Konidala, Daeyoung Kim, Chan Yeob Yeun, Byoungcheon Lee
Vol. 7, No. 1, pp. 111-120, Mar. 2011
Keywords: RFID, Smart Home, Home Network System, Home Server, Secure RFIDBased Applications, RFID Reader-Enabled Devices, RFID Tagged Consumer Items, EPCglobal Architecture Framework
Show / Hide AbstractThe concept of Smart-Homes is becoming more and more popular. It is anticipated that Radio Frequency IDentification (RFID) technology will play a major role in such environments. We can find many previously proposed schemes that focus solely on: authentication between the RFID tags and readers, and user privacy protection from malicious readers. There has also been much talk of a very popular RFID application: a refrigerator/bookshelf that can scan and list out the details of its items on its display screen. Realizing such an application is not as straight forward as it seems to be, especially in securely deploying such RFID-based applications in a smart home environment. Therefore this paper describes some of the RFID-based applications that are applicable to smart home environments. We then identify their related privacy and security threats and security requirements and also propose a secure approach, where RFID-tagged consumer items, RFID-reader enabled appliances (e.g., refrigerators), and RFID-based applications would securely interact among one another. At the moment our approach is just a conceptual idea, but it sheds light on very important security issues related to RFID-based applications that are beneficial for consumers.
Mohammed Alzaabi, Chan Yeob Yeun, Thomas Anthony Martin
Vol. 7, No. 1, pp. 121-136, Mar. 2011
Keywords: Location based services, Anonymity, Location Information
Show / Hide AbstractWith the rapid growth of GPS-enable Smartphones, the interest on using Location Based Services (LBSs) has increased significantly. The evolution in the functionalities provided by those smartphones has enabled them to accurately pinpoint the location of a user. Because location information is what all LBSs depend on to process user¡¯s request, it should be properly protected from attackers or malicious service providers (SP). Additionally, maintaining user¡¯s privacy and confidentiality are imperative challenges to be overcome. A possible solution for these challenges is to provide user anonymity, which means to ensure that a user initiating a request to the SP should be indistinguishable from a group of people by any adversary who had access to the request. Most of the proposals that maintain user¡¯s anonymity are based on location obfuscation. It mainly focuses on adjusting the resolution of the user¡¯s location information. In this paper, we present a new protocol that is focused on using cryptographic techniques to provide anonymity for LBSs users in the smartphone environment. This protocol makes use of a trusted third party called the Anonymity Server (AS) that ensures anonymous communication between the user and the service provider.
Handling Malicious Flooding Attacks through Enhancement of Packet Processing Technique in Mobile Ad Hoc NetworksHyoJin Kim, Ramach, ra Bhargav Chitti, JooSeok Song
Vol. 7, No. 1, pp. 137-150, Mar. 2011
Keywords: Collaborative Attack, Malicious Flooding Attack, Wireless Ad Hoc Network
Show / Hide AbstractMobile ad hoc networks are expected to be widely used in the near future. However, they are susceptible to various security threats because of their inherent characteristics. Malicious flooding attacks are one of the fatal attacks on mobile ad hoc networks. These attacks can severely clog an entire network, as a result of clogging the victim node. If collaborative multiple attacks are conducted, it becomes more difficult to prevent. To defend against these attacks, we propose a novel defense mechanism in mobile ad hoc networks. The proposed scheme enhances the amount of legitimate packet processing at each node. The simulation results show that the proposed scheme also improves the end-to-end packet delivery ratio.
Neda Rohani, Zainab Noferesti, Javad Mohajeri, Mohammad Reza Aref
Vol. 7, No. 1, pp. 151-158, Mar. 2011
Keywords: Bivium, Guess and Determine Attack, Stream Ciphers, Linear Approximations, Entropy
Show / Hide AbstractBivium is a simplified version of Trivium, a hardware profile finalist of the eSTREAM project. Bivium has an internal state size of 177 bits and a key length of 80 bits. In this paper, a guess and determine attack on this cipher is introduced. In the proposed method, the best linear approximations for the updating functions are first defined. Then by using these calculated approximations, a system of linear equations is built. By guessing 30 bits of internal state, the system is solved and all the other 147 remaining bits are determined. The complexity of the attack is O (230), which is an improvement to the previous guess and determine attack with a complexity of order O(252.3).
Deng-Guo Feng, Jing Xu, Wei-Dong Chen
Vol. 7, No. 1, pp. 159-172, Mar. 2011
Keywords: Strong Designated Verifier Signature, Ring signature, Deniable Authenticated Key Exchange, Provable security
Show / Hide AbstractA designated verifier signature is a special type of digital signature, which convinces a designated verifier that she has signed a message in such a way that the designated verifier cannot transfer the signature to a third party. A strong designated verifier signature scheme enhances the privacy of the signer such that no one but the designated verifier can verify the signer¡¯s signatures. In this paper we present two generic frame works for constructing strong designated verifier signature schemes from any secure ring signature scheme and any deniable one-pass authenticated key exchange protocol, respectively. Compared with similar protocols, the instantiations of our construction achieve improved efficiency.
Mengsong Zou, Lansheng Han, Ming Liu, Qiwen Liu
Vol. 7, No. 1, pp. 173-186, Mar. 2011
Keywords: computer virus, Behavior-Based Detection, Dynamic Link Library, Behavior Resource Tree
Show / Hide AbstractDue to the disadvantages of signature-based computer virus detection techniques, behavior-based detection methods have developed rapidly in recent years. However, current popular behavior-based detection methods only take API call sequences as program behavior features and the difference between API calls in the detection is not taken into consideration. This paper divides virus behaviors into separate function modules by introducing DLLs into detection. APIs in different modules have different importance. DLLs and APIs are both considered program calling resources. Based on the calling relationships between DLLs and APIs, program calling resources can be pictured as a tree named program behavior resource tree. Important block structures are selected from the tree as program behavior features. Finally, a virus detection model based on behavior the resource tree is proposed and verified by experiment which provides a helpful reference to virus detection.
Jae-Jung Kim, Seng-Phil Hong
Vol. 7, No. 1, pp. 187-198, Mar. 2011
Keywords: Multi-Factor Authentication, PKI, User Authentication, Biometric Authentication
Show / Hide AbstractUser authentication refers to user identification based on something a user knows, something a user has, something a user is or something the user does; it can also take place based on a combination of two or more of such factors. With the increasingly diverse risks in online environments, user authentication methods are also becoming more diversified. This research analyzes user authentication methods being used in various online environments, such as web portals, electronic transactions, financial services and e-government, to identify the characteristics and issues of such authentication methods in order to present a user authentication level system model suitable for different online services. The results of our method are confirmed through a risk assessment and we verify its safety using the testing method presented in OWASP and NIST SP800-63.
Gaetan Martens, Ruben Verborgh, Chris Poppe, Rik Van de Walle
Vol. 7, No. 1, pp. 199-208, Mar. 2011
Keywords: Multimedia, Metadata Annotation, Semantic Web Technologies
Show / Hide AbstractThis paper describes best-practices in lifting an image metadata standard to the Semantic Web. We provide guidelines on how an XML-based metadata format can be converted into an OWL ontology. Additionally, we discuss how this ontology can be mapped to the W3C¡¯s Media Ontology. This ontology is a standardization effort of the W3C to provide a core vocabulary for multimedia annotations. The approach presented here can be applied to other XML-based metadata standards.
Jung-Min Oh, Nammee Moon
Vol. 7, No. 1, pp. 209-220, Mar. 2011
Keywords: Smart Phone, Culture, Cultural Dimensions Model, MDS, Mobile Application Analysis
Show / Hide AbstractOne of the major factors influencing the phenomenal growth of the smart phone market is the active development applications based on open environments. Despite difficulties in finding and downloading applications due to the small screens and inconvenient interfaces of smart phones, users download applications nearly every day. Such user behavior patterns indicate the significance of smart phone applications. So far, studies on applications have focused mainly on technical approaches, including recommendation systems. Meanwhile, the issue of culture, as an aspect of user characteristics regarding smart phone use, remains largely unexamined throughout the world. Hence, the present study attempts to analyze the highest ranked smart phone applications downloaded and paid for that are ranked the highest in 10 countries (Korea, Japan, China, India, the UK, USA, Indonesia, Canada, France, and Mexico) and we then derive the CDSC (Cultural Dimensions Score of Content) for these applications. The results derived are, then, mapped to the cultural dimensions model to determine the CISC (Cultural Index Score for Country). Further, culturally significant differences in smart phone environments are identified using MDS analysis.