• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.5B
• /
• pp.317-323
• /
• 2005

Broadcast disks are suited for disseminating information to a large number of clients in mobile computing environments. In broadcast disks, the server continuously and repeatedly broadcasts all data items in the database to clients without specific requests. The clients monitor the broadcast channel and retrieve data items as they arrive on the broadcast channel. The broadcast channel then becomes a disk from which clients can retrieve data items. This paper proposes a Timestamp based Concurrency Control (TCC) scheme to preserve the consistency of read-only client transactions, when the values of broadcast data items are updated at the server. Previous schemes tried to reduce transaction aborts by consuming considerable amount of downlink communication from the server to clients for transferring control information. On the other hand, the TCC uses a timestamp field of each data item to describe execution order of server transactions. Clients can allow more transaction executions by checking consistency of their read-only transactions with timestamps of data items. As a result, the TCC can reduce the abort ratio of client transactions with minimal control information to be broadcast from the server.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.12
• /
• pp.3775-3781
• /
• 2009

This aims of this study is to examine the factors influencing on the channel satisfaction and preference of the mobile commerce. This model tests various theoretical research relating to technology acceptance model(TAM), transaction cost theory and service quality. The model is tested Structural Equation Modeling(SEM) using AMOS 7.0 analysis on the sample collected from 320 respondents. The result of hypothesis testing is as follows. First, usefulness, asset specificity, uncertainty, trust and responsiveness were influenced by channel satisfaction. Second, channel satisfaction was influenced positively by channel preference.

• The KIPS Transactions:PartD
• /
• v.8D no.2
• /
• pp.132-144
• /
• 2001

The broadcast environment is asymmetric communication aspect that is typically much greater communication capacity available from server to clients than in the opposite direction. In addition, most of mobile computing systems only allow the generation of read-only transactions from mobile clients for retrieving different types of information such as stock data, traffic information and news updates. Since previous concurrency control protocols, however, do not consider such a particular characteristics, the performance degradation occurs when those schemes are applied to the broadcast environment having quite a high data contention. In this paper, we propose OCC/2VTS (Optimistic Concurrency Control based on 2-Version and TimeStamp) that is most appropriate for broadcast environment. OCC/2VTS lets each client process and commit query transactions for itself by using two version data in cache. If the values of appropriate data items are not changed twice by invalidation report after a query transaction starts, the query transaction is committed safely independent of commitment of update transactions. OCC/2VTS decreases the number of informing server for the purpose of commitment. Due to broadcasting the validation reports including updated recent values, it reduces the opportunity of requesting a recent data values of server as well. As a result, OCC/2VTS makes full use of the asymmetric bandwidth. It also improves transaction throughput by increasing the query transaction commit ratio as much as possible.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.7
• /
• pp.3487-3494
• /
• 2013

Diverse application service such as mobile payment, access control or smart poster have been provided by using smart devices with built-in Near Field Communication technology. Especially, a mobile payment system can provide convenience to its users, but it also can poses including data disclosure while transmitting. There are vulnerabilities while generating session keys used to encrypt data in transaction processes as proposed in KS X 6928, the standard for mobile payment system. Therefore, in this thesis, I analyzed weaknesses of session keys used to encrypt transaction data and proposed a more secure mobile payment system based on NFC to enhance security. The proposed system will provide security functionalities such as key freshness, mutual authentication and key confirmation.

• Journal of Digital Convergence
• /
• v.18 no.2
• /
• pp.23-35
• /
• 2020

Mobile Money is a key factor of financial inclusion that can revolutionize the financial service delivery and hence enhance access to finance in emerging economies, especially the East African countries. This study therefore aims to study the determinants of individual's behavioral intention and usage of Mobile Money services in Ethiopia by usiing the UTAUT2 model. The research model was tested by sampling 200 respondents from different areas of Ethiopia. The analysis results found that Government Support, Facilitating Conditions, Performance Expectancy, Trust and Effort Expectancy are the key factors that affect the usage of Mobile Money service, while Lower Transaction Cost factors and Social Influence were not statistically significant. The findings provide useful information that only government's active efforts and support to promote mobile money services, through appropriate policies and regulations rather than lower transaction cost, can facilitate the adoption and dissemination of such services in Ethiopia.

• Journal of Information Technology Applications and Management
• /
• v.12 no.4
• /
• pp.59-70
• /
• 2005

Flash memories are one of best media to support portable computer's storages in mobile computing environment. The features of non-volatility, low power consumption, and fast access time for read operations are sufficient grounds to support flash memory as major database storage components of portable computers. However, we need to improve traditional transaction management scheme due to the relatively slow characteristics of flash operation as compared to RAM memory. in order to achieve this goal, we devise a new scheme called Flash Two Phase Locking (F2PL) scheme for efficient transaction processing. F2Pl improves transaction performance by allowing multi version reads and efficiently handling slow flash write/erase operation in lock management process. We also propose a simulation model to show the performance of F2PL. Based on the results of the performance evaluation, we conclude that F2PL scheme outperforms the traditional scheme.

• Journal of Information Technology Applications and Management
• /
• v.16 no.1
• /
• pp.169-183
• /
• 2009

The purpose of this research, based on the Media Selection Theory, the Technology Acceptance Model, and the Social Influence Theory, is to investigate the influential factors that affect media selection in banking transactions. Analyses showed that for location sensitive bank windows and ATMs(automatic teller machines), defined as offline-based transaction channels, convenience was the variable affecting media selection. However, in the case of online media not related to location, (phone banking, internet banking, and mobile banking) reliability was the significant variable influencing use. The findings show that banking organizations may benefit from identifying traits of media affecting use, and should differentiate customer services for competitive advantage.

• Journal of the Korea Computer Industry Society
• /
• v.7 no.3
• /
• pp.199-204
• /
• 2006

M-commerce protocols have usually been developed using informal design and verification techniques. However, many security protocols thought to be secure was found to be vulnerable later. With the rise of smart card's usage, mobile e-commerce services with CEPS which is one of e-commerce transaction standards has been increased. In this paper, we describe a methodology to analyze the security of e-commece protocols and identify the security vulnerability of the CEPS based good purchase and e-money load protocols using formal verification technique. Finally, we discuss a countermeasure against the vulnerability in the purchase transaction protocol.

• Journal of Information Technology Applications and Management
• /
• v.12 no.3
• /
• pp.97-109
• /
• 2005

The internet and wireless communication technologies are creating ubiquitous environments in which various services are expected anytime and anywhere. Many hardware facilities have been developed and system structures are suggested for mobile services to realize a ubiquitous computing environment with appropriate quality. But these applications are not designed in the consideration of the general capabilities to perform user's wireless and mobile communication/transaction. Consequently, different needs from users are not sufficiently satisfied yet. In this study, we suggest structure of the emerging network system for mobile commerce that provides users with seamless and ubiquitous environments using location information which exploit context-aware technology.

• Journal of Intelligence and Information Systems
• /
• v.15 no.1
• /
• pp.65-85
• /
• 2009

The main purpose of this paper is to propose a sophistication framework for a global manufacturing network (GMN) driven by a mother company to autonomously propagate and coordinate transaction data that are exchanged among manufacturing partners. The framework is based on conceptual fundamentals of previous research that provide a step toward ultimate successful collaboration in the supply chain and employs mobile agents for the coordination and propagation of transaction data. Maintaining the integrity of transaction data linked to a huge information web is difficult. With the sophistication functionalities of this framework, it becomes easy to effectively control the overall GMN operations and to accomplish the intended goals. The current level of sophistication focuses on the transaction data propagation. The sophistication level may be expanded up to business intelligence in the future.