• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.107-110
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• 2004

IEEE 802.15.3 is wireless Medium Access Control(MAC) and Physical Layer(PHY) specification for high rate WPAN (Wireless Personal Area Network). IEEE 802.15.3 MAC Layer provides Qos with three kinds of acknowledgements; No acknowledgement, Immediate acknowledgement, and Delayed acknowledgement. This paper presents how to improve QoS with new acknowledgement method called Delayed Negative acknowledgement. This paper describes the method of using Delayed Negative acknowledgement and presents the calculation of QoS improvement by using Delayed Negative acknowledgement.

• Fashion & Textile Research Journal
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• v.21 no.1
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• pp.46-58
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• 2019

This study analyzes the effects of lifestyle on wetsuits purchasing behavior and identifies various characteristics among lifestyle groups. A questionnaire survey of 213 domestic consumers with water sport activity and wetsuits experience indicated the following results: 1) Lifestyle factors were analyzed as 6 factors: social relation ships, development orientation, trend & appearance, domestic, positive acknowledgement of hobbies, pursuit of practicality. And the wetsuits selection criteria was 4 factors: wearing fitness, product information, design, reputation. 2) Social relationships, development orientation, positive acknowledgement of hobbies and pursuit of practicality factors had a positive effect fitness. Trend & appearance, development orientation, and pursuit of practicality factors had a positive effect on product information factors ; in addition, development orientation, and trend & appearance, a positive acknowledgement of hobbies factors had a positive effect design factors. Social relationships, trend & appearance, and pursuit of practicality factors had a positive effect on reputation factors. However, trend & appearance factors negatively affected the wearing fitness factors and the positive acknowledgement of hobbies factors had negative effect on product information, reputation factors. 3) The three groups of lifestyle factors showed differences in monthly average purchasing of clothes, average annual purchasing expenditures for water sports related products, number of water sport activity days and frequency, product selection criteria.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.66-71
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• 2008

In this paper, an antenna-switching scheme using negative acknowledgement for hybrid automatic repeat request (H-ARQ) is proposed and analyzed in the Vertical Bell Labs Layered Space-Time(V-BLAST) system, in which the transmit antenna is alternatively switched under retransmission. By analytically evaluating the channel capacity of the proposed scheme over correlated fading channels, it is shown that the adverse effect of the channel correlation is alleviated by the antenna switching scheme. Simulation results demonstrate that the average throughput may be improved in a correlated fading channel without adding much complexity to the process.

• Journal of Communications and Networks
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• v.9 no.3
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• pp.236-246
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• 2007

This paper investigates the performance of the transmission control protocol (TCP) transport protocol over IEEE 802.11 infrastructure based wireless networks. A wireless link is generally characterized by high transmission errors, random interference and a varying latency. The erratic packet losses usually lead to a curbing of the flow of segments on the TCP connection and thus limit TCP's performance. This paper examines the impact of the lossy nature of IEEE 802.11 wireless networks on the TCP performance and proposes a scheme to improve the performance of TCP over wireless links. A negative acknowledgment scheme, selective negative acknowledgment (SNACK), is applied on TCP over wireless networks and a series of ns-2 simulations are performed to compare its performance against that of other TCP schemes. The simulation results confirm that SNACK and its proposed enhancement SNACK-S, which incorporates a bandwidth estimation model at the sender, outperform conventional TCP implementations in 802.11 wireless networks.

• English Language & Literature Teaching
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• v.15 no.2
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• pp.1-25
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• 2009

The purpose of this study is to explore the potential of peer coaching for EFL teachers' professional development. For this study, 12 college teachers in Korea participated in a 10-week program. They were 7 males and 5 females, ranging in age from 24 to 37 years. Data were collected through semi-structured interviews. Reflective analysis was used to analyze individual interview data. From the findings, two significant categories of peer coaching were identified: positive and negative responses to peer coaching experience. However, the overriding themes that emerged from the data were the benefits of peer coaching. The participants were almost unanimous in their acknowledgement of the advantages of peer coaching, such as reflective support through other's eyes, improved working environments, greater teaching strategies, higher professional self-esteem, and awareness of self-directed learning. Negative responses also appeared, mostly in regard to the working principles of implementation; the major issues of difficulties were time management, complexities of implementation procedure, stress and personal vulnerability, and relative lack of reflection and feedback skills. Demonstrating the participants' experiences towards the peer coaching program, this study provides EFL teachers with useful insights into peer coaching as an effective tool of their professional development.

• The Korean Journal of Emergency Medical Services
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• v.7 no.1
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• pp.213-234
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• 2003

The purposes of this study which was done by questionnaire survey and case study of First Aid Certification Program in Seoul Health College were to analyze results and effects of the college financial support program from Ministry of Education & Human Resources Development. The significant 164 data were collected from 300 professors in 8 colleges having the Department of Emergency Care from Oct. 1, 2002 to Dec. 31, 2002 and analyzed using SPSS in terms of t-test, ANOVA, Pearson's correlation coefficient and so on. The conclusions and suggestions from this study were summarized as follows; (1) Degree of acknowledgement about aims, contents, results of the college financial support program was above the middle(participants 4.21, non-participants 3.63) and higher relation than the others in case of participants(r:0.32 p<0.001), planning team(r:0.22 p<0.05). (2) Degree of acknowledgement about improvement of curriculum & educational facilities through the program was above the middle and higher relation than the others in case of participants. (3) Degree of acknowledgement about positive influence on acquirement rate of certification(licence) & job through the program was above the middle and performance & adaptation at work place was higher relation than the others in case of participants. (4) Degree of acknowledgement about positive influence on improvement of learning of student's major through the program was above the middle and higher relation than the others in case of participants. (5) The respondents thought that the program had a negative influence on professor's educational activities & research such as study 40.4%, lecture 23.1%, student guidance 12.5%. (6) When the program was administered by planning team, there were difficulties such as execution of budget 42.1%, cooperation with companies 17.1%, cooperation among program teams 11.8%, when it was administered by non-planning team there were difficulties such as execution of budget 45.5%, cooperation among departments 22.7%, cooperation with companies 13.6%. (7) Because it was too short to execute the budget, the ministry have to select proposed programs before the next school year. (8) This program should be changed temporary, insufficient support into consecutive, sufficient support for more characterization & specialization of the college which has a long-term developmental plan & vision.

• Journal of the Korea Computer Industry Society
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• v.5 no.1
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• pp.123-130
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• 2004

In this paper, an advanced error tracking algorithm by using feedback channel was proposed for error resilient transmission. Using this proposed algorithm, the propagation of errors were reduced within the decoded data over bit error prone network. The addresses of corrupted blocks are reported to encoder by decoder. With negative acknowledgments of feedback channel, the encoder can precisely calculate negative acknowledgments and track the propagated errors by examining the backward motion dependency for proper pixel in the current encoding frame. The error-propagation effects can be terminated completely by INTRA refreshing the affected macro-blocks by using proposed error tracking algorithm. By utilizing the selective four-corner error tracking approximation, the error tracking computations of the proposed algorithm is less than that of the algorithm using full pixel without substantial degradation in video quality. The proposed algorithm can track errors rapidly and accurately.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.83-89
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• 2007

This study is perform to improve the current point at issue of the non-regular employees, comparing the safety and health consciousness of between the regular employees and non-regular employees in manufacturing factory. The investigation is carried out using the statistical analysis. The study presents that most of the non-regular employees answer in the negative the current job satisfaction, work load, work risk, concern on the safety and health, education, occupational safety and health system than the regular employees. For the improvement of these problems, the government's safety and health policy should be changed and acknowledgement of the employer and employee on the safety and health should be improved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.10B
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• pp.1382-1389
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• 2001

움직임 보상-이산 코사인 변환 (motion compensation-discrete cosine transform : MC-DCT) 기반의 동영상 부호화 기법이 부호화 효율성 및 구현의 단순성으로 인해 널리 사용되고 있으나, 에러 환경에서 구조적으로 취약한 면이 있다. 본 논문에서는 다중 메모리 움직임 보상 예측 (long-term memory motion compensated prediction : LTMP) 기반의 다중 레프런스 프레임을 사용하여 에러에 강인한 동영상 부호화 기법을 제안한다. 또한 제안하는 알고리듬에 기반한 에러 은닉 기법 (error concealment : EC)을 구현한다. 즉, R-D (rate-distortion) 최적화에 프레임간 움직임 벡터 (temporal motion vectors)의 확산 인자를 추가하여 에러에 대한 강인성 및 에러 은닉 기법의 효율성을 증가시켰다. 또한, 제안하는 알고리듬은 시간축상의 에러 전파를 피드백 정보 (negative acknowledgement : NAK)를 사용하여 억제한다. 즉, NAK는 채널 에러에 의해 손실된 영역과 에러가 전파된 영역을 추정하여 움직임 보상 영역에서 제외되도록 하는데 이용된다. 따라서, 제안하는 알고리듬은 PSNR 측면에서 FIU (forced intra update)에 근사하는 성능을 보이나, FIU와는 달리 비트율의 증가를 피할 수 있어 제한된 대역폭의 네트웍을 효율적으로 사용할 수 있다. 컴퓨터 모의 실험을 통해 제안하는 알고리듬이 기존의 H.263 및 LTMP 기반의 부호기에 비해 에러 환경에서 주관적 및 객관적 화질 측면에서 성능이 우수함을 보인다.

• The Korean Journal of Health Service Management
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• v.6 no.2
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• pp.193-200
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• 2012

The purpose of this study was to research the opinion and acknowledgement about the clinical chronic disease care system subject to Medical Practitioners that copied the internal medicine and family medicine as a treatment subject and was fulfilled in the purpose of providing a basic data for the improvement and stable establishment of the chronic disease care system and the high blood pressure and diabetes mellitus patient's promotion of health. Results from the research the internal medicine was 79% and the subject's average age was 52.3 years, the proportion that the high blood pressure and the diabetes mellitus took was average 28% and the interest about the system was 65.9%. In the chronic disease care system expansion status the opposition was 75.7%, and the detail field knowledge level was 56.9%. In the opinion field about the system, all fields were shown negative. The chronic disease care system is an important government policy enforcing purposed to effectively manage the yearly increasing chronic disease, but the due to the cold attitude of Medical Practitioners that must actively accept it, the stable establishment of the system is being concerned. Therefore even if it's a good policy if it cant gain the support and agreement of the accepter, in the future when trying to implement a system there should be no idleness in the effort to gain cooperation and understanding to relevant involved ones.