• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.10
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• pp.1405-1411
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• 2018

This paper designs access control system for MS-word(Microsoft-word) document system. The system designed in this paper uses the document-related information by analyzing the MS-word document structure. It is designed to block access to users who can not access the modified information by partially modifying MS-word document information. This makes it impossible to read documents other than those who have access to the MS-word document. This allows you to control access to the MS-word document. A user with access to the MS-word document will be able to retrieve the modified information back to the original information so that the document can be read normally. In this paper, we design and implement experiments. In the experiment, we performed document access if MS-word document information was modified. Experimental results show that the MS-word access control system operates normally.

• Korean Management Science Review
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• v.24 no.2
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• pp.127-142
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• 2007

This study deals with the optimal design of mobile access network connecting base stations(BSs) and mobile switching centers(MSCs). Generally mobile operators constitute their access networks by leasing communication lines. Using the characteristic of leased line rate based on administration region, we build an optimization model for mobile access network design which has much smaller number of variables than the existing researches. And we develop a GUI based optimization tool integrating the well-known softwares such as MS EXCEL. MS VisualBasic, MS PowerPoint and Ip_solve, a freeware optimization software. Employing the current access network configuration of a Korean mobile carrier, this study using the optimization tool obtain an optimal solution for both single MSC access network and nation-wide access network. Each optimal access network achieves 7.45% and 9.49% save of lease rate, respectively. Considering the monthly charge and total amount of lease line rate, our optimization tool provides big amount of save in network operation cost. Besides the graphical representation of access networks makes the operator easily understand and compare current and optimal access networks.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.63-71
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• 2013

WAVE(Wireless Access for Vehicular Environment) System is a communication technology to monitor system failure and vehicle functions and management services to prevent possible incidents of driving a vehicle. In this paper, we have designed and implemented the mutual message processing through parameter between WME management module that manages WAVE system and MLME that manages the upper layer MAC(Media Access Control) module. Also, in order to verify the validity, we have carried out experiments to compare the speed of data processing by dividing data of 1Mbyte, 2Mbyte, 3Mbyte into the packets of 2KByte and 4KByte. Experiments data processing speed of 2KByte packet were shown about 173.62ms in 1MByte, 2MByte about 352.61ms, 3MByte about 550.13ms and, data processing speed of 4KByte packet, 1MByte approximately 87.56ms, 2MByte about 177.94ms, 3MByte about 277.18ms. Therefore, in WAVE system, the mutual messages processing through the parameters between WME and MLME module can be utilized in the various service of ITS(Intelligent Transportation Systems) depending on the speed of data processing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6C
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• pp.649-655
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• 2009

Mean acquisition time (MAT) is the most important performance measure for code acquisition systems, where a shorter MAT implies a better code acquisition performance. Keshavarzian and Salehi proposed the multiple-shift (MS) algorithm for code acquisition in optical code division multiple access (O-CDMA) systems. Performing two steps acquisition, the MS algorithm has a shorter MAT than that of the conventional serial-search (SS) algorithm. In this paper, we propose a rapid code acquisition algorithm for O-CDMA systems. By using an efficient combination of local signals, correlation value, and the sign of correlation value, the proposed algorithm can provide a shorter MAT compared with that of the MS algorithm. The simulation results show that the proposed algorithm presents a shorter MAT than that of the MS algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.755-758
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• 2011

분산된 데이터를 효율적으로 관리하기 위해 일반적으로 DBMS을 사용하고 있다. DBMS에는 여러 시스템들이 있지만 대부분 상용판매이기 때문에 시스템을 구축하는데 있어 비용적인 문제가 있을 뿐만 아니라 사용방법도 복잡하여 사용하기 어려운 면이 있다. 이에 본 연구에서는 전문적인 지식 없이도 조작과 관리가 쉽고 체계적이고 통합적으로 관리가 가능하며 MS Office 제품과의 호환성이 뛰어난 MS-Access를 이용한 시스템구축 사례를 제안한다. MS-Access를 이용하면 서버나 기타 시스템 없이도 기존에 사용하고 있는 컴퓨터에서 데이터베이스를 운영할 수 있고 따로 전문적인 DB관리자가 필요가 없다. 본 논문에서는 이러한 점을 이용하여 프로젝트를 관리할 수 있는 시스템을 구현하였다. 이 시스템은 비용투자에 열악한 중소기업이나 비영리 단체에서 효율적으로 사용할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.713-720
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• 1996

In recent, the demand of mobile communication system is increasing rapidly. However, since wireless resources is limitted, the protocol to utilize wireless resource efficiently is needed. Up to now, Slotted CDMA_ALOHA(S_CDMA_ALOHA) and Mini-Slotted CDMA_ALOHA(MS_CDMA_ALOHA) methods are proposed as a CDMA_ALOHA mechanism, and it is turned out that MS_CDMA_ALOHA offers betterperformance than S_CDMA_ALOHA mechanism. Also, IS-95 multiple access mechanism has been proposed as common air interface(CAI) protocol of CDMA digital cellular system. However, in former study, the performance evaluations were made without considertion of chnnel characteristics of wireless communication environment. In this paper, a new access mechanism for improring the performance in the DS/CDMA digital cellular environment is suggested. This mechanism is adaptive to the channel condition and based on the conventional MS_CDMA_ALOHA mechanism. Also, the performance of new access mechanism is compared with that of conventional mechanisms, through computer simulation. According tot h simulation results, it is shown that the proposed NA_CDMA_ALOHA(Noise-Adaptation CDMA_ALOHA) mechanism offers better performance than conventional three CDMA_ALOHA mechanisms in view of mean delay time and system throughput characteristics. This phenomenon is due to the fast that NA_CDMA_ALOHA mechanism controls the access attempts efficiently based on the channel condition in heavy traffic environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.1075-1081
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• 2008

In this paper, we propose a code acquisition algorithm using optical orthogonal code (OOC) for optical code division multiple access (CDMA) systems. Generally, a good code acquisition algorithm offers short mean acquisition time (MAT). The conventional multiple-shift (MS) algorithm consists of two stages and has shorter MAT than that of well-known serial-search (SS) algorithm. This paper proposes a novel code acquisition algorithm called enhanced multiple-shift (EMS) algorithm. By using multiple thresholds, the proposed EMS algorithm provides shorter MAT compared with that of the MS algorithm. The simulation results show that the EMS algorithm presents shorter MAT compared with the MS algorithm in both single-user and multi-user environments.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.3
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• pp.97-104
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• 2015

This paper will feature designs for security vulnerability based on MS-SQL Database and OLE connectivity by checking the MS-SQL database password policy, the user account password access attempts, a user without password, and password does not be changed for a period of time. This paper uses the MS-SQL database and C++ linkage in order to use the OLE DB function. The design module should judge presence or absence of security vulnerability by checking database password policy, the user account password access attempts, a user without password, password does not be changed for a period of time. The MS-SQL database password associated with a feature, judging from the many features allows you to check for security vulnerability. This paper strengthen the security of the MS-SQL database by taking the advantage of the proposed ability.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.45-51
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• 2010

Appearance of a cloned AP(Access Point) causes MS(Mobile Station) to break an association with a normal AP(Access Point). If signal power of the cloned AP is stronger than that of the normal AP, MS associates with the cloned AP. Therefore, MS is easily exposed to attackers who installed the cloned AP. In this paper, we distinguish cloned AP from normal AP by using the association time and frame sequence number between normal AP and MS, then isolates the cloned AP. The simulation by NS-2 shows that our mechanism isolates efficiently a cloned AP and builds safer wireless LAN environment.

• Korean Journal of Cognitive Science
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• v.21 no.4
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• pp.505-534
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• 2010

The purpose of this study was aimed to compare the lexical access and representation of semantic system in the bilinguals. The participants(late Korean-English bilinguals) performed the word-picture matching task. The task was to decide whether the pictures presented after the words(basic-level categories) represent the Korean(L1) or English(L2) words' meaning or not. The stimuli were consisted of common object belonged to four different categories(animal, part of body, clothes, tool). To control the translation strategies, the SOA(stimulus onset asynchrony) were manipulated as 650ms(Exp. 1) and 200ms(Exp. 2). In both experiment, the RTs were faster in L1 condition. The decision time of the part of body categories were shorter than the animal in L1 condition. In L2 condition, clothes were responded faster than the tools. The differences of the lexical access time implied that the bilingual semantic system seemed to be structured by more sub-level categories than the super-level, living or non-living things, and the ways to access the bilingual lexicon might be differentiated according to the languages.