• 한국통신학회논문지
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• 제28권1C호
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• pp.72-80
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• 2003

본 논문은 멀티패스 페이딩이 존재하는 CDMA 채널에서 새로운 빔형성 알고리즘을 통해 적응 배열 안테나의 성능을 향상시키기 위한 최적의 웨이트 벡터를 구하는 방법을 제시하였다. 제안한 빔형성 알고리즘은 멱승법을 근간으로 하며, 전체 계산량이 O(4N)밖에 되지 않는 선형화 된 멱승법(power method) 알고리즘이다. 여기서 N은 안테나 수를 의미한다. 제안된 알고리즘의 성능은 IS-2000 1X CDMA 환경에서 심볼 에러율(symbol error rate), 사용 가능자수(allowable capacity), 수렴도(convergence) 등에 대한 분석을 통해 확인하였다. 성능분석 결과 적응 배열 안테나 시스템은 기지국 셀 내에서 기존 안테나 시스템에 비해 6-10배정도 사용 가능자수가 증가하였다. 또한, 제안 알고리즘은 심볼 에러율, 수렴도, 계산량의 모든 경우에서 기존 알고리즘에 비해 우수한 성능을 보임을 확인하였다.

• The Journal of Korean Physical Therapy
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• 제23권2호
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• pp.45-52
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• 2011

Purpose: The purpose of this study was to investigate the effect of electroacupuncture on NeuN expression in ventral horn motor neurons of spinal cord, changes in pain thresholdchanges in motor function in rats with partially dissected sciatic nerves. Method: A total of 120 male Sprague-Dawley rats were randomly divided into two groups, a control group and a group administered electroacupuncture at ST36, LI11 and SP9 with 120 Hz and 0.5 mA. Animals were sacrificed on days 1, 3, 7, 14 and 28 after nerve injury (the sciatic nerve was partially dissected). The pain threshold was recorded by an Analgesia? meter and a BBB? score was calculated for motor function. After preparing lumbar spinal cord slide sections, they were immunostained with NeuN antisera (1:2,500). Results: The numbers of NeuN immunoreactive neuronsin the electroacupuncture group was increased compared to the control group. The numbers of NeuN immunoreactive neurons on days 14 and 28 day were different (p<0.05), as were the numbers on days 3 and 7 (p<0.01). The pain threshold BBB score for the electroacupuncture group was higher than for controls. Conclusion: The increase in pain threshold, BBB-score and number of NeuN immunoreactive neurons inventral horn motor neurons of spinal cord in rats withnerve dissection showed that electroacupuncture can attenuate pain transduction and increase motor function. Also, NeuN was a good marker for identifying the degree of nerve cell loss after nervous system injury.

• Applied Microscopy
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• 제22권1호
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• pp.89-102
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• 1992

This research was undertaken to determine the effects of the anticancer and immunosuppressive drug cyclophosphamide (CP) on the epididymal caput of the male rat in terms of ultrastructural alteration and protein analysis by SDS-PAGE at different groups; control group, 1 week group, 3 weeks group, 5 weeks group were treated with saline (control group) or CP at doses of 20 mg/kg/week, 1 time a week, respectively. In the cytoplasm of the principal cells on the epididymis, the mitochondrial outer and inner membranes were significantly swollen or disrupted. The lumens of rough endoplasmic reticulum (rER) were also swollen, and the number of Golgi vesicles were increased, respectively. It is suggested that treatment with CP alters the specific cell organelles in the epididymis. CP caused changes in protein concentrations in caput of epididymis after CP treatment. Total proteins of 32 to 37 species such as lactate dehydrogenase, carnitine acetyltransferase and succinate dehydrogenase were expressed in the caput fluid. Then the more CP was increased, the more concentration of proteins caused to decrease, synthesize or increase in epididymis. In contrast to the control group, in particular carnitine acetyltransferase and the other 9 proteins in the caput fluid were decreased or disappeared, respectively, whereas lactate dehydrogenase and the other 5 proteins in the caput fluid were increased or synthesized, respectively. The other proteins are not showed distinctive difference. These alterations could be direct mediated by toxic effects of the drug on the epithelium or be secondary to changes in the spermatozoa as a result of the CP treatment.

• KSBB Journal
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• 제18권3호
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• pp.207-210
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• 2003

Locus coeruleus (LC)에는 전체 노르아드레날린성 뉴런의 절반 가량이 모여 있는데, 여기서 노르아드레날린성 뉴런이 뇌의 거의 모든 부위로 신경자극을 보내게 된다. LC는 알츠하이머병, 파킨슨병, 헌팅턴병 같은 여러 가지 신경퇴행성 질환에서 공통적으로 타격을 받는 주요 부위이다. 뇌 유래 신경영양인자, BDNF가 LC 노르아드레날린성 뉴런을 포함한 중추신경계 뉴런들의 분화와 신경세포 생존에 중요한 조절자로 작용한다. 본 연구에서는 LC 노르아드레날린성 신경세포에서 여러 가지 작은 분자들과 성장인자들이 BDNF 생산을 촉진할 수 있는지를 조사하였다. 실험에 사용한 분자들로는 neuropeptides, cytokines, 성장인자, 신경전달물질들과 세포내 신호전달물질들이 포함되었다. 여러 가지 작은 분자들과 성장인자들 중에서 FGF8b, BMP-4, forskolin 그리고 dibutyrl cGMP가 LC 노르아드레날린성 뉴런에서 BDNF 분비를 뚜렷하게 증대시킨 것으로 판명되었다. 특히, BMP-4는 BDNF 생산을 2.5배 이상 증가시켰다. LC 노르아드레날린성 뉴런에서 BDNF를 증가시킨 물질들은 여러 가지 신경퇴행성 질환에서 신경세포가 손실되는 것을 막거나 지연시킬 수 있을 것이므로, 치료제나 증상완화제로서의 가능성이 높다.

• 한국통신학회논문지
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• 제32권8A호
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• pp.785-793
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• 2007

본 논문에서는 TP 케이블을 이용하여 100Mbps의 전송 속도를 지원하는 100Base-TX Ethernet 수신기의 디지털 신호 처리부를 제안하였다. 제안하는 디지털 신호 처리부는 자동 이득 조절기, 심볼 동기 복원기, 적응 등화기, BLW 보정기로 구성되어 있으며 초기 위상에 상관없이 150m까지 $10^{-12}BER$이하의 성능을 보였다. 제안하는 신호 처리부는 일부 블록을 제외한 모든 부분을 디지털로 구현하였으며 적응 등화기와 BLW 보정기 연동 구조는 기존의 적응 등화기 에러 값을 이용하는 구조에 비하여 MSE가 약 1dB정도의 성능 향상을 가져왔다. 설계한 디지털 신호 처리부는 Verilog-HDL로 구현되었으며 삼성 $0.18{\mu}m$ 라이브러리를 사용하여 합성 결과 동작 속도는 7.01ns 이며 총 게이트 수는 128.528 게이트였다.

• 한국태양에너지학회 논문집
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• 제35권4호
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• pp.67-75
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• 2015

PV module is conventionally connected in series with some solar cell to adjust the output of module. Some bypass diodes in module are installed to prevent module from hot spot and mismatch power loss. However, bypass diode in module exposed outdoor is easily damaged by surge voltage. In this paper, we study the thermal and electrical characteristics change of module with damaged bypass diode to easily find module with damaged bypass diode in photovoltaic system consisting of many modules. Firstly, the temperature change of bypass diode is measured according to forward and reverse bias current flowing through bypass diode. The maximum surface temperature of damaged bypass diode applied reverse bias is higher than that of normal bypass diode despite flowing equal current. Also, the output change of module with and without damaged bypass diode is observed. The output of module with damaged bypass diode is proportionally reduced by the total number of connected solar cells per one bypass diode. Lastly, the distribution temperature of module with damaged bypass diode is confirmed by IR camera. Temperature of all solar cells connected with damaged bypass diode rises and even hot spot of some solar cells is observed. We confirm that damaged bypass diodes in module lead to power drop of module, temperature rise of module and temperature rise of bypass diode. Those results are used to find module with a damaged bypass diode in system.

• 한국약용작물학회지
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• 제13권2호
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• pp.103-109
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• 2005

When we carried out an anti-stress study using the extracts of A. senticosus, R. coreanus, F .japonica root, and A. fruticosa fruit grown in Korea, the results showed that blood cell counts returned to normal levels fastest with R. coreanus after stress application. The total WBC count was decreased in mice due to stress, whereas the number of lymphocytes was increased. The serum glucose level was higher in the control group compared with the comparative stress group. The weight of each organ to returning to normal level was significantly faster in those mice treated with the extracts compared with those in control groups. Especially, it even return to that of normal level with R. coreanus extract, suggesting that the administration of the plant extracts in this study would affect hormonal activities in the body to increase immune activities. F. japonica root that showed the highest anti-stress activities maybe effective for lipid and carbohydrate metabolism. These results would provide basic data to examine anti-stress effects of natural plants. Further in-depth studies could contribute in the development of functional plant materials with anti-stress activities.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 International Meeting 2000
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• pp.94-101
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• 2000

We investigated the viral contamination of water environment including tap water in Korea. River water used for source water was analyzed about monthly between 1997 and 1999 over a period 26 months. A total of 22 tap water samples were collected in 10 sites in 2 urban areas between 1997 and 1998 over a 11 months. All samples were examined for infectious enteroviruses and adenoviruses by a cell culture technique followed by PCR amplification. To identify the recovered viruses from tap water, sequence analysis of PCR products was performed. Infectious viral particles were detected in river water all year round, ranging from 0.93 to 17.3 Most Probable Number of Infectious Unit (MPNIU) /100L. Tap water samples also contained infectious viral particles. The frequency of enteroviruses and adenoviruses in tap water were $50.0\%$ (11/22) and $36.7\%$ (8/22), respectively. Both enteroviruses and adenoviruses were detected in five tap water samples $(22.7\%)$. The level of viral contamination in tap water was quite high, ranging from 0.2 to 2.9 MPNIU/100L, far above the recommended virus level in drinking water set by the U.S. EPA. Poliovirus type 1 derived from vaccine was frequently detected and the remainder comprised coxsackievirus B type or echovirus type 6, which were causative agents of aseptic meningitis in Korea in 1997 and 1998, respectively. Several types of adenovirus were detected in tap water samples and some water samples were found to contain adenoviruses which were closely related to enteric adenovirus type 40 and 41. This stusy shows that surface water and tap water in Korea may be exposed to the risk of viral contamination, especially from recently recognized viruses and this constitutes a potential public health hazard.

• 대한한의학회지
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• 제21권2호
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• pp.68-78
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• 2000

Objective : This research was performed to investigate protective effects of Sophora subprostrata, against ischemic brain damage after a middle cerebral artery(MCA) occlusion. The effect was estimated using histological test, neurobehavioural test, and biochemical test. Methods : Rats(Sprague-Dawley) were divided into four groups: Sham operated group, MCA occluded group, Sophora subprostrata administrated group after MCA occlusion, and Normal group. The MCA was occluded by intraluminal method. Sophora subprostrata was administrated orally twice(l and 4 hours) after middle cerebral artery occlusion. The neurobeavioural test was performed at 3 hours, 6 hours, 9 hours and 24 hours after the surgery by posture reflex test and swimming behavioural test. All groups were sacrificed at 24 hours after the surgery. The brain tissue was stained with 2% triphenyl tetrazolium chioride(TTC) or 1 % cresyl violet solution, to examine effect of Sophora subprostrata on ischemic brain tissue. The blood samples were obtained from the heart of rats. Tumor necrosis factor-a level was measured from sera using Enzyme-Linked Immunoabsorbent Assay(ELISA). Results : The results showed that (1) Sophora subprostrata reduced infarct size and total infarct volume by 54.8% compared to the control group, (2) that neuronal death, which was shown by decrease in cell number and size, was attenuated significantly in the boundary area of the infarction, (3) that serum $TNF-{\alpha}$ㆍlevel was reduced significantly, and finally, there was significant recovery of motor deficit at 3 hours after MCA occluded by Swimming behavioural test. Conclusions :In conclusion, Sophora subprostrata has protective effects against ischemic brain damage at the early stage of ischemia.

• Clinical and Experimental Pediatrics
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• 제62권11호
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• pp.422-427
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• 2019

Background: Polyomavirus BK (BKV) infection is an important cause of graft loss in kidney transplant patients. Purpose: The purpose of this study was to evaluate clinical findings and risk factors for BKV in pediatric patients after kidney transplantation. Methods: This retrospective single-center study included 31 pediatric kidney transplant recipients from January 2002 to December 2017. Two patients received 2 transplantations during the study period, and each transplant was analyzed independently. Total number of cases is 33 cases with 31 patients. BKV infection was confirmed from blood samples via periodic quantitative polymerase chain reaction. Results: The mean age at kidney transplantation was 11.0±4.7 years, and the male-to-female ratio was 2.7:1. Three patients had a past medical history of high-dose chemotherapy and autologous stem-cell transplantation for solid tumors. Nine patients (27.3%) developed BKV infection. The median period from kidney transplantation to BKV detection in blood was 5.6 months. There was no statistically significant difference in estimated glomerular filtration rate between patients with and those without BKV infection. Among 9 patients with BKV viremia, 7 were treated by reducing their immunosuppressant dose, and BKV was cleared in 6 of these 7 patients. In the other 2 BKV-positive patients, viremia improved without immunosuppressant reduction. Conclusion: BKV infection is common in children with kidney transplantation and might not have affected short-term renal function in our patient sample due to early immunosuppressant reduction at the time of BKV detection.