• 한국인터넷방송통신학회논문지
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• 제11권5호
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• pp.185-192
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• 2011

본 논문에서, 고속 PLC 시스템을 위한 반복 부호화 기법인 이중 이진 터보 코드의 성능을 분석하고 실험하였다. PLC 시스템은 고속 데이터 전송에 열악한 환경을 가지므로, 이를 보상하기 위한 강력한 에러 정정 기법은 반드시 필요하다. PLC 채널 모델로서 M. Zimmerman가 안한 모델을 사용하였으며, 노이즈 모델로 Middleton Class A 모델을 적용하였다. 시스템 성능은 비트오류율 (BER) 측면에서 평가하였다. 모의실험 결과로부터 이중 이진 터보 코딩이 PLC 시스템에 상당한 코딩 이득을 제공한다는 것을 확인하였다. 또한 복호화 프로세스에서 사용된 반복 횟수가 증가할수록 BER 성능이 현저하게 향상된다는 것을 알 수 있었으며, 부호율이 증가할수록 시스템 성능이 감소하고, 부호율이 감소할수록 시스템 성능이 증가한다는 것도 확인하였다.

• Nuclear Engineering and Technology
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• 제19권2호
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• pp.122-129
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• 1987

핵연료 피복재 (Zircaloy-4)에 생기는 얇은 산화층의 두께에 따른 고온에서의 산화 거동을 관찰하기 위하여 실험과 수치 계산을 수행하였다. 산화 실험은 수중기와 물의 혼합 분위기에서 지르칼로이-4판재 시편을 $650^{\circ}C$에서 600초, 1,800초 동안 산화시켜서 산화층을 형성시킨 후 $700^{\circ}C$ 와 85$0^{\circ}C$ 사이의 온도에서 산화 거동을 관찰하였다. 기산화층의 두께가 두꺼울수록 고온에서의 산화율은 as-received cladding의 경우보다 낮았다. 기산화층이 형성된 시편에서는 산화율 천이 영역이 나타났으며 이 영역은 산화 온도가 올라감에 따라 점차로 소멸되었다. 기산화층의 영향은 낮은 온도($700^{\circ}C$)에서 가장 뚜렷하게 나타났다. 수치 계산 결과에 의하면, 산화층 증가율과 무게 증가는 실험 결과와 비슷하게 기산화층의 두께에 영향을 받았다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권3호
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• pp.205-217
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• 2005

Distraction osteogenesis is a technique of lengthening bone including soft tissue by gradual separation of surgically divided bone surfaces. Although the biomechanical, histological, and ultrastructural changes associated with distraction osteogenesis have been widely described, the molecular mechanisms governing the formation of new bone in distracted bone segments remain largely unclear. However, such information has significant clinical implications because it may enable targeted therapeutic manipulations designed to accelerate osseous regeneration. The purpose of this study was to evaluate the expression of TGF-$\beta$1, IGF-I and bFGF in distraction osteogenesis according to different distraction rates in a rabbit's mandible. When twenty-four adult rabbits underwent open osteotomy between the premolar and mental foramen, an external bilateral distraction device was applied. Latency was allowed for five days before distraction. Three different distraction rates were 0.7 mm/day (A, n=8), 1.4 mm/day (B, n=8) and 2.4 mm/day (C, n=8). The distraction device was activated with the same distraction rhythms of twice a day until 4.9 mm (A & B group) and 8.4 mm (C group) length gains was achieved. The animals were sacrificed at postoperative 3, 7, 14 and 28 days. The bony specimens were stained with H&E for histologic examination, and RT-PCR analysis was done for the identification of the expression of TGF-$\beta$1, IGF-I and bFGF. The results obtained from this study were as follows : The 0.7 mm/day and 1.4 mm/day distraction rate groups were shown to improve regenerative bone formation on radiographic and histologic examination. Also, TGF-$\beta$1, IGF-I and bFGF expression increased in the 0.7 mm/day and 1.4 mm/day distraction rate groups. But the 2.4 mm/day distraction rate group specimen was different with adjacent normal bone and hardly expressed of growth factors. These findings suggest that improved new bone formation in the 0.7 mm/day and 1.4 mm/day distraction rates is associated with enhanced expression of TGF-$\beta$1, IGF-I and bFGF by mechanical tension stress. Additionally, the 0.7 mm/day and 1.4 mm/day distraction rate groups were significantly different from the 2.4 mm/day distraction rate group in the expression of growth factors. According to the above results, it seems possible to apply a distraction rate of up to 1.4 mm/day a day in rabbit's mandible. And further studies are needed to evaluate growth factors of TGF-$\beta$1 and IGF-I, which are excellent in expression.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1388-1393
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• 2000

The present study was conducted to examine the feasibility of utilising bamboo (Bambusa arundinacea) shoot shell (BSS) in ruminants. Chemical composition, rumen degradability and some antinutritional compounds were determined for fresh and boiled BSSs to evaluate its feed value and safety. Thirty-two Holstein heifers were allocated to four groups and used to investigate the response in growth rate to supplementing ammoniated rice straw with fresh shell (phase 1) or silage of boiled BSS (phase 2). All animals were offered ammoniated straw ad libitum with 1kg of cotton seed meal (phase 1) or 0.5 kg of cotton seed meal and 0.5 kg of concentrate mixture (phase 2) per head per day. The BSS was supplemented at levels of 0, 3, 6 or 9 kg/d (phase 1) and 0, 5, 10 or 15 kg/d (phase 2) (as fed basis). The BSS was very high in moisture content, and its contents of crude protein and neutral detergent fiber were 13~16% DM and 65~76% DM, respectively; boiling resulting in higher moisture and protein. No hydrocyanic acid was detected in both BSSs and content of tannins was negligible. Rumen degradability of BSS was reasonably high, and with boiling the rapidly degradable fraction decreased, and potentially degradable component increased. Silage of the boiled BSS was slightly lower in both rapidly and slowly degraded fractions than the fresh BSS. Animals consumed all supplemented BSSs without any adverse health problems. Intake of ammoniated straw decreased with the increasing levels of BSS, but total intake was higher in almost all supplementary groups than in the non-BSS. Heifers had a higher growth rate in phase 1 with fresh BSS than in phase 2 with ensiled shell, and daily weight gains were 622, 629, 744 or 690 g in phase 1, and 578, 575, 677 or 635 g in phase 2 at four BSS levels, respectively. For both phases growth rate was significantly higher for the animals in groups 3 and 4 than those in groups 1 and 2 (p<0.01), with little difference between groups 1 and 2 (p>0.05) but significant difference between groups 3 and 4 (p<0.05). Supplementation with BSS also resulted in an improved feed conversion rate, with the least concentrate consumption in group 3 for both phases. It is concluded that the BSS has a high potential nutritional value as indicated by its medium protein content, reasonably high rumen degradability, and that inclusion of BSS in ammoniated rice straw diet is not only safe to animals, but also may improve growth rate of ruminants and feed conversion rate. It may be disadvantageous to use high amounts of BSS in ammoniated straw diets.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.492-496
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• 2006

This study has the purpose a remodeling plan of apartment complexes in residential areas. Based on the analysis on characteristics of circumstance surrounding it and economic gains for the residents who live in the apartments, this study suggests a concrete model to accomplish the purpose. The apartment in Nowon-gu was studied and some apartments which have same characteristics with the target of remodeling plan were interviewed and answered the questionnaire. To grasp the functions required and planning factors of apartment's remodeling, the questionnaire focused on the residents' request in each levels of their own entire hosing complex, just a building in the hosing complex area, and their own household. The conclusion is, (1) The major problems of common apartment complexes were serious aging, insufficient everyday life facilities and high rate of the residents' dissatisfaction. (2) The study suggests remodeling plans of an apartment complexes in each levels of their own entire hosing complex, just a building in the hosing complex area, and their own household, such as, underground parking area, tree-planting of first and top areas, improvement of a housing floor plan, a view of the front side, and so on.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권2호
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• pp.389-405
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• 2014

Outdated Channel State Information (CSI) was proved to have negative effect on performance in two-way relay networks. The diversity order of widely used opportunistic relay selection (ORS) was degraded to unity in networks with outdated CSI. This paper proposed a multiple relay selection scheme for amplify-and-forward (AF) based two-way relay networks (TWRN) with outdated CSI. In this scheme, two sources exchange information through more than one relays. We firstly select N best relays out of all candidate relays with respect to signal-noise ratio (SNR). Then, the ratios of the SNRs on the rest of the candidate relays to that of the Nth highest SNR are tested against a normalized threshold ${\mu}{\in}[0,1]$, and only those relays passing this test are selected in addition to the N best relays. Expressions of outage probability, average bit error rate (BER) and ergodic channel capacity were obtained in closed-form for the proposed scheme. Numerical results and Simulations verified our theoretical analyses, and showed that the proposed scheme had significant gains comparing with conventional ORS.

• 전기전자학회논문지
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• 제3권1호
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• pp.109-117
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• 1999

본 논문에서는 급속 열처리 공정에서 필수적인 빠르고 정밀한 웨이퍼의 온도제어기법을 제안하였다. Bang- Bang/PID 제어기법은 빠른 온도상승률을 만족하고, 오버슈트와 정상상태 오차를 줄이도록 한다. 즉 초기에 허용 가능한 최대전력을 공급하는 일종의 Bang-Bang 방식의 제어를 하고, 설정온도와 출력에서 측정되는 온도와의 차이가 어느 정해진 범위보다 작을 때 PID 제어를 수행한다. 또한 PID 이득을 정하기 위해 ARX 모델로 식별된 플랜트에 Kappa-Tau 동조법이 사용되었다. 개발된 제어기는 실험용 RTP 장비에 적용하여 그 성능을 평가하였다.

• 대한기계학회논문집B
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• 제28권6호
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• pp.697-704
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• 2004

Bifurcation behavior of ignition and extinction of catalytic reaction is theoretically investigated in a stagnation-point flow. Considering that reaction takes place only on the catalytic surface, where conductive heat losses are allowed to occur, activation energy asymptotics with a overall one-step Arrhenius-type catalytic reaction is employed. For the cases with and without the limiting reactant consumption, the analysis provides explicit expressions, which indicate the possibility of multiple steady-state solution branches. The difference between the solutions with and without reactant consumption is in the existence of an upper solution branch, and the neglect of reactant consumption is inappropriate for determining extinction conditions. For larger values of reactant consumption, the solution response is all monotone, suggesting that multiple solutions are not possible. It is shown that bifurcation Damkohler numbers increase (decrease) with increasing of conductive heat loss (gain) on the catalytic surface, which means that smaller (larger) values of the strain rate allow the surface reaction to tolerate larger heat losses (gains). Lewis number of the limiting reactant can also significantly affect bifurcation behavior in a similar way to the effect of heat loss.

• 대한한방부인과학회지
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• 제20권4호
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• pp.41-55
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• 2007

Purpose: This study is to examine anti-obesity effect and cytotoxicity of the long-term oral administration of Sinomenium acutum (Bang-gi, SA) Methods: Using diet-induced obesity C57BL/6 mouse model, anti-obesity effect and DNA chip expression and cytotoxicity of the long-term oral administration of this herbal extract were investigated. Results: The herbal extract treated groups were arrested in weight increment only when they were lodged together. Such effects were abolished when they kept individually. SA fed mice behaved very rudely and violently. On the basis of histological studies of liver tissues and also in vitro cytotoxicity tests of the liver and kidney cell lines, no significant toxicity was found by 14 weeks of SA treatments. However, we found significant changes in gene expression profile in SA treated group by micro-array analysis. In case of SA group, up-regulated genes were 1,213 and down-regulated ones were 2,558. Some of lipid metabolism related genes also significantly changed in both treatment groups. Conclusion: SA had effects of increasing the basal metabolic rate by stimulating the sympathetic nervous systems.

• 한국식품영양학회지
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• 제11권5호
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• pp.550-555
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• 1998

The purpose of this study was to investigate the effects of n-3 polyunsaturated fatty acids(PUFA) on glucose and lipids metabolism in high-fat diet rate. Rats were randomly assigned to normal, high-fat with n-3 PUFA and high-fat dietary groups. Experiments were carried out after 5 weeks feeding with prescriptive diets following 7 hrs fasting. Body weight gains tended to be higher in high-fat fed rats than normal. Blood glucose was increased (p<0.05) by high-fat diet compared with normal diet, and decreaseed (p<0.05) to normal level by n-3 PUFA. Plasma insulin level was significcantly higher (p<0.01) in high-fat diet rats than that of normal-diet rats, and also decreased (p<0.01) by n-3 PUFA. Glucose up take of soleus muscle in vitro was decreased markedly in high-fat fed rats than normal diet rats at 0, 1, 10, and 100nM insulin concentration. Therefore insulin sensitivity and responsiveness were decreased by high-fat diet. Omega-3 PUFA made a recover(p<0.01) insulin sensitivity to almost normal level, and improved (p<0.05) insulin responsiveness in some extent. In conclusion, the results suggest that metabolic disorder of glucose and insulin resistance of skeletal muscle are caused by high-fat diet and n-3 PUFA can ameliorate metabolic disorder and insulin resistance.