• ETRI Journal
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• 제33권5호
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• pp.670-678
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• 2011

This paper investigates the design and performance of a digital on-channel repeater (DOCR) for use in Advanced Television Systems Committee (ATSC) digital television (DTV) broadcasting. The main drawback of a DOCR is the echo interference caused by coupling between transmitter and receiver antennas, which induces system instability and performance degradation. In order to overcome this problem, an echo canceller based on the adaptive echo channel estimation (ECE) technique has been researched and applied for a DOCR. However, in the case of ATSC, the pilot signal, which is used for carrier synchronization, may cause a DC offset error and reduce the isolation performance of the echo canceller for a DOCR in an ATSC network. Moreover, since the multipath fading effect of a radio channel usually occurs in a real environment, it should be minimized to improve the overall performance of a DOCR. Therefore, due to the limited isolation performance of echo canceller and the multipath fading effect, an interference cancellation system (ICS) is proposed for a DOCR in an ATSC network. The performance of the proposed DOCR with an ICS is evaluated by software simulation and hardware test results.

• 한국항공우주학회지
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• 제44권2호
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• pp.123-130
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• 2016

본 논문에서는 항공기 조종사 헬멧에 장착된 HMD(헬멧시현기, Helmet Mounted Display)에 비행정보 및 임무정보를 조종사의 시선(Line of Sight)과 일치시켜 시현하기 위한 헬멧자세 추적시스템(HTS, Helmet Tracking System)을 설계 및 구현했다. HMD 시스템의 기능과 성능은 HTS의 성능에 기반하므로 이를 고려하여 동작의 실시간을 보장하고 정확도를 높이기 위해 관성센서와 광학식센서의 데이타를 융합처리하여 다양한 운용 환경에서도 강건한 성능을 제공할 수 있는 HTS를 설계 및 구현 했다. 구현된 HTS의 효용성을 검증하기 위하여 테스트 베드 환경에서 오차 발생시 동작의 정확도 및 실시간성등을 검증하였다.

• 대한물리의학회지
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• 제13권1호
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• pp.147-154
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• 2018

PURPOSE: This study examined the ability of experimental socks combined with a functional insole to reduce plantar foot pressure in healthy subjects. METHODS: The study enrolled 15 subjects. An in-shoe measurement device was used to measure the peak plantar pressure while walking. The peak forefoot, midfoot, and hindfoot plantar pressure data were collected under two conditions: the subjects were wearing their own socks and while they were wearing the experimental socks. The paired t-test was used to determine the differences in peak plantar pressure between the two conditions at all three positions. RESULTS: Wearing the experimental socks resulted in a significantly higher peak plantar pressure in the medial forefoot and midfoot areas than wearing one's own socks (p<.05), and also in significantly lower peak plantar pressure in the medial and lateral hindfoot (p<.05). However, there were no significant differences of peak plantar pressure between experimental and own socks in middle and lateral forefoot (p>.05). CONCLUSION: The experimental socks combined with a functional insole decreased plantar pressure in the hindfoot and supported the medial longitudinal arch. However, it is necessary to change the design and material of the forefoot area in the functional insole to prevent foot ulcer at that location in people with diabetes mellitus.

• 디자인학연구
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• 제20권3호
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• pp.215-224
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• 2007

본 연구에서는 발달장애 아동을 위한 VR-Tangible Interaction 치료 시스템을 디자인하고 개발하였다. 본 치료시스템의 목적은 감각통합치료, 사회성 훈련, 협응능력 측정의 세 분야에 있어 발달장애 아동이 VR과 Tangible Interaction을 즐겁게 체험하는 과정에서 아동의 능력을 진단하고 자연스럽게 치료효과를 얻을 수 있도록 하는 것이다. 디자이너와 의사, 심리학자, 공학자가 학제적인 연구를 통하여 총 14종의 인터랙션 시나리오를 작성하고 콘텐츠를 디자인했다. 표정을 보고 사람의 마음 짐작하기, 상대방이 바라보고 있는 대상이 어느 것인지 맞추기, 지시봉으로 가상의 풍선 터뜨리기 등의 인터랙션이 디자인되었다. 프로토타입 시스템을 제작하고 임상테스트를 실시한 결과 발달장애 아동들이 VR-Tangible Interaction이라는 새로운 환경에 자연스럽게 적응하는 것을 확인할 수 있었으며 긍정적인 치료효과들을 예견하게 하는 정성적, 정량적인 결과들을 얻을 수 있었다.

• 산경연구논집
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• 제9권4호
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• pp.43-52
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• 2018

Purpose - The purpose of this article is to examine the effects of perceived value, satisfaction, and continued use intention of e-service Quality of taxi-booking apps. Research design, data, and methodology - The questionnaire was created to examine every relevant variables to practical and theoretical implications. The pilot survey was conducted for 15 days from April 7^th to April 21^st in 2016. Their total numbers were 354 surveys. But 330 copies were used for the analysis except 24 of them. To make a more effective analysis, several analysis tools and analysis programmes were used, such as IBM SPSS and AMOS. Results - The results are as follows. First, all variables of e-service quality except safety make influences on perceived value. Second, e-service quality except safety makes influences on satisfaction. Third, perceived value makes influence on satisfaction and on intention of continued use. Fourth, satisfaction makes influence on intention of continued use. Conclusions - First, 5 variables are very limited. more valuable variables are need to test with this model. Second, this study was conducted only in China. So there may be possible to the representatives. To use this model for better analysis and application abroad, more characteristics and strategic factors should be considered like the local culture of a particular country, attributes for different environment etc.

• 대한암한의학회지
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• 제26권1호
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• pp.49-59
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• 2021

Objective: Insomnia is a very common symptom of cancer and has a substantial effect on the patients' quality of life. This study aimed to identify the effects of foot reflexology on insomnia in cancer patients. Methods: The study employed a before-after test design on a single group of 13 cancer patients with insomnia, selected by convenience sampling in Daegu. The foot reflexology treatment comprised 30-min sessions twice a week over four weeks. Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) were measured at the baseline, at 2 and 4 weeks, and after 4 weeks post treatment completion. Brief Fatigue Inventory-Korean (BFI-K), Functional Assessment of Cancer Therapy-General (FACT-G), and Heart Rate Variability (HRV) were measured at baseline, post-treatment, and 4 weeks after completing treatments. Results: Thirteen patients (mean age 44.77 ± 6.70 years), with thyroid, breast or cervical cancer, were included in the study. Post-treatment, PSQI (from 12.33 ± 3.17 to 8.54 ± 3.43, p<0.001), ISI (from 20.33 ± 3.88 to 13.38 ± 4.23, p<0.001), FACT-G (from 49.6 ± 13.27 to 61.35 ± 14.45, p<0.001), and BFI (from 6.46 ± 0.91 to 5.00 ± 2.02, p<0.001) scores improved significantly over those at the baseline. Conclusion: Foot reflexology can be a good alternative treatment to improve insomnia, fatigue, and quality of life in cancer patients

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.463-466
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• 2005

As the distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the distributed generation units would be interconnected to the existing grids. This new generation technology is linked to a large number of factors like economics and performance, safety and reliability, market regulations, environmental issues, or grid connection constrains. KEPOD (Korea Electric Power Corporation) is performing the project to develope the Distributed Micro Gas Turbine (MGT) technologies by using Swine BID-ENERGY. This paper describes the plans and strategies for the renewable energy of MGT on actual grid-connection under Korean situations. KEPOD also, has a research plan on bio-gas pretreatment system applicable to our domestic swine renewable resources and is performing concept design of pilot plant to test grid operation. In addition, this testing will be conducted in order to respond to a wide variety of needs for application and economic evaluation in the field of On-site generation.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.585-588
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• 2007

As the distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the distributed generation units would be interconnected to the existing grids. This new generation technology is linked to a large number of factors like economics and performance, safety and reliability, market regulations, environmental issues, or grid connection constrains. KEPCO (Korea Electric Power Corporation) is performing the project to develope the Distributed Micro Gas Turbine (MGT) technolgies by using Swine BIO-ENERGY. This paper describes the plans and strategies for the renewable energy of MGT on actual grid-connection under Korean situations. KEPCO also, has a research plan on bio-gas pretreatment system applicable to our domestic swine renewable resources and is performing concept design of pilot plant to test grid operation. In addition, this testing will be conducted in order to respond to a wide variety of needs for application and economic evaluation in the field of On-site generation.

• 제어로봇시스템학회논문지
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• 제12권7호
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• pp.713-718
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• 2006

Supersonic jet fighter aircraft have several different weapon loading configuration to support air-to-air combat and air-to-ground delivery of weapon modes. Especially, asymmetric loading configurations could result in decreased handling qualities for the pilot maneuvering of the aircraft. The design of the T-50 lateral-directional roll axis control laws change from beta-betadot feedback structure to simple roll rate feedback structure and gains such as F-16 in order to improve roll-off phenomena during pitch maneuver in asymmetric loading configuration. Consequently, it is found that the improved control law decreases the roll-off phenomenon in lateral axes during pitch maneuver, but initial roll response is very fast and wing pitching moment is increased. In this paper, we propose the lateral control law blending between beta-betadot and simple roll rate feedback system in order to decreases the roll-off phenomenon in lateral axes during pitch maneuver without degrading of roll performance.

• International Journal of Quality Innovation
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• 제1권1호
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• pp.89-96
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• 2000

Evolutionary operation (EVOP) is a continuous improvement system which explores a region of process operating conditions by deliberately creating some systematic changes to the process variable levels without jeopardizing the product. It is aimed at securing a satisfactory operating condition in full-scale manufacturing processes, which is generally different from that obtained in laboratory or pilot plant experiments. Information on how to improve the process is generated from a simple experimental design. Traditional EVOP procedures are established on the assumption that the variance of the response variable should be small and stable in the region of the process operation. However, it is often the case that process noises have an influence on the stability of the process. This process instability is due to many factors such as raw materials, ambient temperature, and equipment wear. Therefore, process variables should be optimized continuously not only to meet the target value but also to keep the variance of the response variables as low as possible. We propose a scheme to achieve robust process improvement. As a process performance measure, we adopted the mean square error (MSE) of the replicate response values on a specific operating condition, and used the Kruskal-Wallis test to identify significant differences between the process operating conditions.