• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6C
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• pp.883-892
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• 2004

Recently, in order to improve high speed data transmission and spectral efficiency in wireless communication systems, the study on the combination OFDM and space-time coding is active. Also, a solution to improve system capacity in multiuser systems is to use adaptive antennas. In a system using STBC, the signals transmitted from two transmit antennas are superposed at the receive antenna and the interference between two transmit antennas of a user occures. Thus it is difficult to apply the conventional beamforming techniques for single antenna to the systems using space-time coding. In this Paper, we present the MMSE beanforming technique using training sequence for STBC-OFDM systems in reverse link and evaluate the performance by using various parameters in TU and HT channels.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_2
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• pp.585-592
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• 2013

CBIR is an effective tool to search and extract image contents in a large remote sensing image database queried by an operator or end user. However, as imaging principles are different by sensors, their visual representation thus varies among image modality type. Considering images of various modalities archived in the database, image modality difference has to be tackled for the successful CBIR implementation. However, this topic has been seldom dealt with and thus still poses a practical challenge. This study suggests a cross modality CBIR (termed as the CM-CBIR) method that transforms given query feature vector by a supervised procedure in order to link between modalities. This procedure leverages the skill of analyst in training steps after which the transformed query vector is created for the use of searching in target images with different modalities. Current initial results show the potential of the proposed CM-CBIR method by delivering the image content of interest from different modality images. Despite its retrieval capability is outperformed by that of same modality CBIR (abbreviated as the SM-CBIR), the lack of retrieval performance can be compensated by employing the user's relevancy feedback, a conventional technique for retrieval enhancement.

• Journal of Communications and Networks
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• v.16 no.1
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• pp.18-25
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• 2014

In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multiple-output (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute he transmit precoder and inform its quantized index to the associated user via limited rate feedback link. We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load to maintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF.

• Journal of Korean Institute of Industrial Engineers
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• v.9 no.2
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• pp.9-25
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• 1983

The purpose of this study was to film up computerized analyses for both kinematic posture(film analysis) and muscle dynamics (EMG) during a weight-lifting motion. (Snatch, Clean and Jerk) Using a motor drive camera (3.5 frames/sec) and a Location Analyzer, motion tracks of 13 landmarks, which were attached to the major joints, during the motion were converted into digital values. At the same time, EMG amplitudes from 11 major muscle groups were recorded. Recorded data were processed via analog/hybrid computer (ADAC 480) and digital computer (PDP 11/44). Landmark locations and EMG amplitude were integrated by a computerized routine. Computer output included graphic reproductions on sepuential dislocations of body segments, center of gravity of body segments and the associated changes on EMG amplitude such as % EMG's of major muscle group during a weight lifting motion. The results strongly suggest that the computerized motion-EMG integration can provide a further working knowledge in selection and in training of workers and athletes. Suggestions for a further study include additional device for velocity measurement, expansion of the link model for biomechanical analysis and other implementations necessary for athletic application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.601-610
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• 2004

In this paper, the performance of an adaptive array antenna using Constant Modulus Algorithm (CMA) based on the signal structure for the IMT-2000 3GPP specification reverse link of an asynchronous direct sequence code division multiple access (DS-CDMA) system are evaluated. In addition, the performance is compared with the array antenna using Least Mean Square (LMS) based on the training signal. The simulation parameters such as the number of multipath, mu10pa1h intensity profiles between path, spreading gain and multiuser etc., are considered in the Monte Carlo simulation. Simulation results demonstrate an adaptive array antenna using CMA may give more capacity gain than the amy antenna using LMS in the case of multipath fading channel.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.41-50
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• 2020

The paper aims to investigate auditors, auditing firms and other external factors that affect quality of information technology audit in Vietnam. We conducted 2 types of data collections including direct and on survey. For direct survey, we sent directly to auditors at the training classes organized by State Securities Exchanges Commission. An online survey was established and Google doc link was provided to the Big4 and non-Big4 auditors. We received 138 survey responses in that 90 auditors came from Big4 and 48 auditors from non-Big4 firms. The data are analyzed using a factor analysis and compare means approaches to illustrate the potential IT audit quality factors and identify differences between two groups of auditors. The results show that independence and accounting knowledge and audit skills are the most important factors. And since external auditors perform many assurance services, the independence is critical. The result also shows that the auditors need to have enough competent and professional skills when conducting an audit, especially within an IT environment that requires high quality. The findings suggest a similar pattern of two groups in the context of Vietnam and some factors of auditors and auditing firms appear to have a statistically significant impact on quality of IT audit.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.599-606
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• 2008

In this paper, the channel estimation performance of proposed TSC (TSC-S) is investigated in terms of the BER and BLER performances when HSR is considered for GERAN evolution system. The performance is evaluated by the link level simulation and is compared with the other TSC proposal (TSC-E). Numerical results show that the performance employing the TSC-S is almost same to that using the TSC-E. In the case of cochannel interferences, the similar tendency is shown, when joint least square is adopted for channel estimation.

• English Language & Literature Teaching
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• v.16 no.3
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• pp.317-337
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• 2010

The present study has a dual purpose to investigate the current state of school English library and needs required for its effective use, and to propose a reading program at the school library. The literature on school library was reviewed. A questionnaire survey was done to find out the current situation of English library at the secondary school. The analysis of 26 secondary English teachers' responses reveals that there was the absence of librarians or reading specialists at the school English library. It was also found that the uses of the English library were limited due to the absence of the specialists, no guidelines, and no link between the curriculum and the library use. A case study on a 2-week special reading program at the school English library was conducted and 15 middle school students took part in the project. The participants took pre- and post-tests to identify their reading level using a software and did a variety of reading activities using the books selected according to their level. The comparison of the tests shows that most of the students' reading level improved after the reading program. The analysis of their views on the program and its effects reveals that they gained confidence in reading and their vocabulary understanding was improved. Some suggestions are made for the effective management of the school English library.

• Korean Journal of Childcare and Education
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• v.14 no.4
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• pp.109-126
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• 2018

Objective: The purpose of the present study was to explore the moderating role of children's verbal ability in the relation between shyness and teacher-child relationships. Methods: Participants were 200 children, their mothers, and their kindergarten teachers. Children's shyness was rated by their mothers and teachers, and children's verbal ability was measured using the language problem solving ability test. And teachers completed a rating scale in order to examine the teacher-child relationship. The collected data were analyzed using correlations and hierarchical multiple regressions. Results: Children's shyness had a negative relation to close teacher-child relationships. And child's verbal ability was significantly related to teacher-child relationships. Hierachical regression analysis indicted to the interaction of child's shyness and verbal ability predicted close teacher-child relationships. Children's shyness, those who demonstrated the lowest level of child's verbal ability, was significantly associated with close teacher-child relationships. Children's shyness had no significant relation to close teacher-child relationships, especially for the highest level of children's verbal ability. Conclusion/Implications: We suggested that verbal ability training for children might be valuable for shy children in order to buffer the link between shyness and teacher-child relationships.

• Journal of the Korean Society for Library and Information Science
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• v.38 no.2
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• pp.161-187
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• 2004

This study concerns DB quality of the Web databases which has been produced in medical science. For the quality evaluation of Embase and PubMed, 10 evaluating criteria were developed on the basis of literature review. The evaluation result showed that PubMed has superiority to the currentness, accuracy, completness, consistency, ease of use, customer support, searchability, cost, and network ＆ H/W on DB, but Embase has only superiority to the coverage. It is needed for purchasing, user training, and library service based on the above evaluation result.