• Journal of Korean Society for Geospatial Information Science
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• v.12 no.1 s.28
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• pp.45-53
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• 2004

The purpose of this paper is to study a scheme to ITS service which enables the data (spatial, non-spatial and image) sharing among heterogeneous system (various environment) with employing the concept of object orientedness and to show Location Reference Technique of ITS Space DB for interoperability. Data warehouse service, query object service, interface object service, and naming object service have been identified for this. In addition, a metadata management object service and persistent object service based system framework has been devised. The proposed skeletal framework would be expected to be functioning well for ITS data sharing environment and for the interoperability support.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.640-645
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• 2011

The purpose of this article is to investigate ways of making the cloze test more valid as an English proficiency test so that it can provide a better format for the cloze test especially to the non-native teachers in EFL environments. This investigation identifies ways of validity in terms of materials, deletion rates, item characteristics and scoring methods used in cloze tests. An increase in test validity can be accomplished by knowing how the four factors affect the cloze test results and how to manipulate them. Practical suggestions are provided for teachers to design a cloze test. Teachers can develop the reliability and validity of cloze tests by manipulating the four factors. In seeking a more valid and reliable cloze format, this research gives some suggestions based on a literature review. We can conclude that a cloze test can be valid only when teachers are aware of the factors which affect the test result and the ways to handle the factors to make the test appropriate for their test purposes.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.5_6
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• pp.280-289
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• 2003

Deadlock recovery-based routing algorithms in wormhole networks have gained attraction due to low hardware complexity and high routing adaptability Progressive deadlock recovery techniques require a few dedicated resources to transmit deadlocked packets rather than killing them. Selection of deadlocked packets is primarily based on time-out value which should be carefully determined considering various traffic patterns or packet length. By its nature, current techniques using time-out accompany unignorable number of false deadlock detections especially in a heavy-loaded network or with long packet size. Moreover, when a deadlock occurs, more than one packet may be marked as deadlocked, which saturate the resources allocated for recovery. This paper proposes more accurate deadlock detection scheme which does not make use of time-out to declare deadlock. The proposed scheme reduces the probability to detect false deadlocks considerably. Furthermore, a single message is selected as deadlocked for each cycle of blocked messages, thereby eliminating recovery overheads.

• Journal of KIISE
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• v.42 no.5
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• pp.681-689
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• 2015

Personal information includes information about a living human individual. It is the information identifiable through name, resident registration number, and image, etc. Personal information which is collected by institutions can be wrongfully used, because it contains confidential information of an information object. In order to prevent this, a method is used to remove personal identification elements before distributing and sharing the data. However, even when the identifier such as the name and the resident registration number is removed or changed, personal information can be exposed in the case of a linking attack. This paper proposes a new anonymization technique to enhance data utility. To achieve this, attributes that are utilized in service tend to anonymize at a low level. In addition, the anonymization technique of the proposal can provide two or more anonymized data tables from one original data table without concern about a linking attack. We also verify our proposal by using the cooperative game theory.

• Journal of Korea Multimedia Society
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• v.7 no.5
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• pp.689-697
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• 2004

Rapid advances in mobile computing and the availability of wireless communications will soon provide mobile users with the ability to access data regardless of the location of the user or of the data. SRA(Static Replica Allocation) that is traditional scheme has been used for the replication method on the server. This replicates the data on the replica server after a moving host has been transferred to the cell. This strategy is simple and can easily relocate data. However, if a mobile user does not exist in the cell, the replicated data can be deleted in order to maintain data consistency. In addition to, if the mobile host leaves from replicated cell, it is difficult to access data in terms of replication route. Therefore, this paper proposes a new method of relocation based on data consistency strategy called USRAC(User Selection Replica Allocation based on Consistency) and also analyzes access cost according to the moving rate of mobile users, according to the access rate of mobile hosts, and according to the number of cells of mobile users and mobile hosts.

• Journal of Korea Multimedia Society
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• v.10 no.9
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• pp.1197-1208
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• 2007

These days, most of SMART card, JAVA card, picked up the JAVA Card Platform gets the position as a standard. Java Card technology provides implantation, platform portability and high security function to SMART Card. Compared to normal Smart Card, JAVA card has a defect that is a low running speed caused by a distinctive feature of JAVA programming language. Factors that affect JAVA Card execution speed are the method how to save the data and install the applets of JAVA Card installation instrument. In this paper, I will offer the plan to improve JAVA Card program's loading and execution speed. At Java Card program, writing, updating and deleting process for data at EEPROM can be improved of Java Card speed by using high speed RAM. For this, at JAVA Card as a application of RAM, I will present prefetching LRU-ORL Buffer Cache Technique that is suitable for Java Card environment. As a data character, managing all data created from JAVA Curd at Buffer Cache, decrease times of recording at maximum for EEPROM so that JAVA Card program upload and execution speed will be improved.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.9-17
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• 2019

As the IoT environment becomes more popular, the safety of the M2M environment, which establishes the communication environment between objects and objects without human intervention, becomes important. Due to the nature of the wireless communication environment, there is a possibility of exposure to security threats in various aspects such as data exposure, falsification, tampering, deletion and privacy, and secure communication security technology is considered as an important requirement. In this paper, we propose a new method for group key generation and exchange using trap hash collision hash in existing 'M2M communication environment' using hash collision, And a mechanism for confirming the authentication of the device and the gateway after the group key is generated. The proposed method has attack resistance such as spoofing attack, meson attack, and retransmission attack in the group communication section by using the specificity of the collision message and collision hash, and is a technique for proving safety against vulnerability of hash collision.

• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.91-99
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• 2018

Discrete event simulation environments often need to be modified because additional questions to systems may become apparent while observing the simulation results repeatedly. It leads to increasing development budget and depreciating the effectiveness of the environment. To avoid the modifications and to generate the altered results, this paper applies an Event Control Model (ECM) with control functions that modulate, delete and generate the events at the simulation time. In addition, this paper suggests an easier approach for domain-users, who do not want to program at source code level, by using ECM templates. The simulators with the ECMs can have better extensibility because it becomes more adaptable to possibly unanticipated changes. It prevents increasing development costs due to modifications or development of new models by M&S experts, and it provides a new alternative step to domain users. To support the effectiveness of this approach, this paper describes a relevant example, which is composed of an initial simulation model based on our empirical studies. It will show that there exist the uncountable benefits because the existing simulator is reused by domain users without new projects.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.67-72
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• 2006

Because computer system is complex gradually from fast growth of the Internet and sudden increase of Internet user and scale is growing, and dependence for computer system is rising gradually, data damage by mistake or disaster is big enough to can not imagine. Usually is continuous if wish to inform through internet and must update data stably, we should manage so that precious data is not erased from sudden problem through periodic backup. Plan to protect data safely for this should be readied. This paper proposes system that can make effective backup environment because consider environment and achievement method in these data management side. That is, implements system that achieve data backup and restore selectively in internet. Backup and restore about data had stored through browser even if disconnect directly to server because it is possible connect in internet by advantage of proposing system are available. Also, This system can manage data stored to server more efficiently by using selectively both backup and restore two methods.

• 한국노년학
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• v.32 no.4
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• pp.1181-1197
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• 2012

This study aims to validate the Attitudes to Aging Questionnaire(AAQ), which was recently developed in foreign countries, for Korean elderly. Using a sample of 320 older individuals living in Seoul, Gyeonggi, Chungcheong areas, statistical analyses including item analysis, exploratory factor analysis, convergent validity analysis were attempted to AAQ which composed of three factors with 24 items. In result, the three factor model of AAQ(including psychosocial loss, physical change, and psychological growth) were reconstructed in which new three factors(psychological loss, social loss, and change and growth in body and mind) were confirmed and three items were deleted. Reliability and convergent validity of AAQ-21 were confirmed. AAQ-21 would be useful to researchers and practitioners working with older adults for systematically assessing the attitudes to aging of older individuals and thus contribute to development of social policies and welfare programs for the elderly.