YangSun Lee

Enhanced secure anonymous authentication scheme for roaming service in global mobility networks

Abstract User authentication scheme is an important issue for providing secure roaming service to users of mobile devices. In 2008, Wu, Lee and Tsaur proposed an enhanced anonymous authentication for roaming environment. In this paper, we show weaknesses of Wu–Lee–Tsaur’s schemes such as failing to achieve anonymity and perfect forward secrecy, and disclosing of legitimate user’s password. Therefore, we propose a new enhanced scheme that uses Elliptic Curve Diffie–Hellman (ECDH) to overcome these weaknesses and improve performance. We also demonstrate that our scheme not only overcomes these weaknesses but also provides mutual authentication and resistance to a man-in-the-middle attack. Compared with previous schemes that use public key cryptosystem with certificates, our scheme is more efficient. Moreover, our scheme does not use timestamps, so it is not required to synchronize the time.

A localization algorithm based on AOA for ad-hoc sensor networks

Knowledge of positions of sensor nodes in Wireless Sensor Networks WSNs will make possible many applications such as asset monitoring, object tracking and routing. In WSNs, the errors may happen in the measurement of distances and angles between pairs of nodes in WSN and these errors will be propagated to different nodes, the estimation of positions of sensor nodes can be difficult and have huge errors. In this paper, we will propose localization algorithm based on both distance and angle to landmark. So, we introduce a method of incident angle to landmark and the algorithm to exchange physical data such as distances and incident angles and update the position of a node by utilizing multiple landmarks and multiple paths to landmarks.

Improving positioning accuracy for VANET in real city environments

With advances in technology and the economy, people are more inclined to buy cars. However, as a result, people forfeit their lives and property through accidents due to traffic congestion and traffic chaos. To ensure safe driving, anti-collision warning applications have been widely discussed. Most vehicular safety applications use vehicular positioning and vehicular communication technologies to avoid car accidents. With Vehicular Ad Hoc Networks, it is common to use the global positioning system (GPS) as the vehicular positioning tool owing to its comprehensive development in vehicular navigation. However, there are factors that affect GPS positioning accuracy (e.g., multipath effect, atmospheric effect, etc.). To improve GPS vehicular positioning accuracy, we propose a cooperative positioning algorithm that can improve localization accuracy. We also demonstrate that our algorithm can work well in a real city environment.

Localization Algorithm Design and Implementation to Utilization RSSI and AOA of Zigbee

In this paper, we has implemented the localization algorithm through RSSI and AOA of Zigbee. The RSSI (Received Signal Strength Indicator) method is used for the localization of Zigbee and affected a lot by intensity, distance and interruption of signals. The combined algorithm of AOA (Angle of Arrival) and RSSI has been designed and implemented to make up the weaknesses of RSSI. As long as we knew, although the previous system has been implemented and used through the UWB (Ultra Wide-Band) or CSS communication methods, the firstly implemented system is the location recognition algorithm through RSSI and AOA of Zigbee. In this paper has obtained the result from the repeated tests to achieve the measurement of location with the accuracy of average 35 ~ 36 cm when the suggested system was placing the beacon on the four corners of 2 dimensional rectangular space with 4m wide and 2m long, and the receiver on the random space.

Decision tree construction on GPU: ubiquitous parallel computing approach

General Purpose Graphic Processing Unit (GPGPU) computing with CUDA has been effectively used in scientific applications, where huge accelerations have been achieved. However, while today’s traditional GPGPU can reduce the execution time of parallel code by many times, it comes at the expense of significant power and energy consumption. In this paper, we propose ubiquitous parallel computing approach for construction of decision tree on GPU. In our approach, we exploit parallelism of well-known ID3 algorithm for decision tree learning by two levels: at the outer level of building the tree node-by-node, and at the inner level of sorting data records within a single node. Thus, our approach not only accelerates the construction of decision tree via GPU computing, but also does so by taking care of the power and energy consumption of the GPU. Experiment results show that our approach outperforms purely GPU-based implementation and CPU-based sequential implementation by several times.

Adaptive Internet of Things and Web of Things convergence platform for Internet of reality services

Recently, Internet of things (IoT) and Web of Things (WoT) lead us to the excellent era of connected everything device. However, the devices hardly show the property of the autonomous connectivity and the self-cooperation for applying in real-world environments. The purpose of this paper was to propose the adaptive IoT and WoT convergence platform that enables things to dynamically implement the smart Web without any controls from users. The adaptive IoT and WoT convergence platform, proposed in this paper, is a new type of platform which provides global inter-compatibility to help users to easily communicate with things by connecting through the webs. Through mashup of the things connected to the Web, coarsely or finely, this proposal can guarantee an efficient IoT or WoT platform management, adaptive synchronization between the things, a stable platform environment, and creating new services. The performance of our proposed platform is tested via experiments which verify that its simulations are satisfactory.

On gender differences in consumer behavior for online financial transaction of cosmetics

Abstract The popularity of the Internet has enabled a wide variety of services. Due to increasing pricing levels and material costs over years, enterprises have intended to lower their financial costs by Internet marketing and online financial transactions, by which renting cost, facility setup cost and manpower cost can be saved, and advertising cost is lowered for increasing the number of potential customers. Hence, Internet marketing and online financial transactions have become a market territory for which each enterprise competes. In the market, male consumers no longer mainly shop for 3C products online, and now are becoming more diverse in their shopping selections. Male cosmetics and skincare products comprise a market with great growth potential that is yet to be developed. The purpose of this study is to explore whether gender differences exist or not in perception, importance and satisfaction for online financial transactions of cosmetics. The online questionnaire survey method was used for this study. A total of 600 surveys were distributed. Once the invalid replies were excluded, a total of 567 effective samples were recovered. The results from this study show significant gender differences in the “amount of money spent per purchase of cosmetics”, “the most recent online purchase of cosmetics”, “the time spent on cosmetics”, “amount of money spent each month on cosmetics”, “amount of money spent per time on cosmetics”, “the time spent on buying cosmetics online” and “the satisfaction with the most recent online purchase of cosmetics”. There were also significant differences in the level of importance assigned to “brand reputation”, “fresh scent”, “natural ingredients”, “reasonable price”, “suitable skin type”, “professionalism of service personnel”, “recommended by advertising” and “ease of use”.

Design and Implementation of an Objective-C Compiler for the Virtual Machine on Smart Phone

For each platform, for smart phone contents, a unique development environment exists and thus suitable development methods and development languages must be used for each platform. A problem of this development environment is that when contents are created for a number of platforms, an increase in expenses occurs. SVM(Smart Virtual Machine) is a virtual machine solution which is being developed to overcome this problem by using SIL(Smart Intermediate Language) as an intermediate language. SIL is capable of accommodating ISO/IEC C++, Java, Objective-C and other object-oriented programming. In this paper, the Objective-C compiler for the virtual machine is designed and virtualized which creates stack based virtual machine codes, not objective codes when using contents previously developed for the use on other platforms.

Java Bytecode-to-.NET MSIL Translator for Construction of Platform Independent Information Systems

This paper presents the java bytecode-to-.NET MSIL translator, to construct a platform independent information system, which enables the execution of the java program in .NET environment without JVM(Java Virtual Ma-chine), translating bytecodes produced by compiling java programs into MSIL codes. Java, one of the most widely used programming languages recently, is the language invented by James Gosling at Sun Microsystems, which is the next generation language independent of operating systems and hardware platforms. Java source code is compiled into bytecode as intermediate code independent of each platform by compiler, and also executed by JVM. .NET language such as C# and .NET platform in Microsoft Corp. has been developed to meet the needs of programmers, and cope with Java and JVM platform of Sun Microsystems. After compiling, a program written in .NET language is converted to MSIL code, and also executed by .NET platform but not in JVM platform. For this reason, we designed and implemented the java bytecode-to-.NET MSIL translator system for programs written in java language to be executed in the .NET platform without JVM.

Mapping granularity and performance tradeoffs for solid state drive

Evolving NAND flash-based Solid State Drives (SSDs) tend to get denser and faster, and these are quickly becoming popular in a wide variety of applications. Flash-based SSDs are composed of dozens of non-volatile flash memories with multi-channel and multi-way architecture. Due to the physical limits, Flash Translation Layer (FTL) is employed for the management between host requests and flash requests operations. Among many roles of FTL, mapping management is main key of SSD performance. This paper presents tradeoffs of page-level FTL mapping granularity for appropriate target performance of SSDs. The mapping management is designed with regard to the SSD architecture such as multi-channel and multi-way. Three mapping tradeoff issues are addressed: static and dynamic mapping, mapping unit size, and caching issue. The simulation results shows that various page-level FTL mapping granularities have a decisive effect on SSD design; not only the performance issue, but also resource management.