IMT-2000 송신기 RF 시스템 설계 및 성능 분석

최호준,지만구,김학선 한밭대학교 산업과학기술연구소 2001 논문집 Vol.5 No.-

In this paper, the RF system of IMT-2000 transmitter is designed and analyzed. We derived RF system requirements of minimum performance for IMT-2000 transmitter from analysis of test condition in 3GPP standard(3GPP TS 34.121(v.3.2.0)) and 3GPP2 standard (TIA/EIA/IS-98-C). Using RF system requirements of minimum performance, RF system of W-CDMA and cdma2000 transmitter is designed. Maximum and minimum output power test, spurious emission test, intermodulation test is simulated to a performance analysis. and then, we performed optimization on the parameter value of power amplifier that severely affect the system performance. Simulation results for W-CDMA and cdma2000 are presented.

CPW급전을 이용한 UWB 안테나 설계

최석호,이성훈,김학선,박종권 한밭대학교 정보통신전문대학원 2004 정보통신전문대학원 논문집 Vol.2 No.1

본 논문은 CPW급전 구조와 CST사의 Microwave Studio 사용하여 UWB 안테나를 설계하였다. 시물레이션 결과 제안된 안테나의 대역폭은 3.O5-13GHz를 가지고 방사패턴은 무지향성의 형태를 갖는 것을 보였다. In this paper, we have designed a UWB antenna using CPW feed line and used the Microwave Studio of CST to simulate the UWB antenna. Simulated results show that antenna bandwidth is 3.05-13GHz and radiation pattern is omni-directional.

H형 패치 안테나 설계

최석호,김학선,박종권 한밭대학교 정보통신전문대학원 2003 정보통신전문대학원 논문집 Vol.1 No.1

이 논문은 H형 패치 안테나가 무선통신에 적합하다는 것을 보여준다. H형 패치 안테나는 기존의 사각형 패치 안테나처럼 작은 크기, 적은 제작비용, 고조파 성분에서의 비 공진과 같은 몇 가지 장점을 가진다. H형 패치 안테나의 기본적인 이론과 설계과정 및 시뮬레이션 결과를 소개하였다. In this paper, H-shaped patch antenna suitable for wireless communication is presented. This antenna has several advantages compared to conventional rectangular microstrip patch antennas such as small size, low cost fabrication and absence of harmonic resonance. The fundamental principle, simulated result and design procedure are presented.

남북상사중재위원회 운영상의 문제점과 활성화방안

최석범,박근식,김태환,김재학,박선영 한국중재학회 2007 중재연구 Vol.17 No.1

The commercial relationship between South and North Korea is defined under the concept of economic relation and cooperation. To resolve any dispute that can arise from the trade and investment relations between South and North Korea, 'Agreement on the Procedures to Resolve Commercial Arbitration of South-North Korea' came into force in August 2003. Commercial Arbitration Committee of South-North Korea will be organized as the member lists of the committee were exchanged in July 2006 between South and North Korea. This committee must become a central system to settle the trade and investment disputes between South and North Korea. North Korea's Foreign Economic Arbitration Act was enacted to provide the foreign investors with the safe measures in their investments such as dispute resolution. But this Act can not dispute the trade and investment disputes between South and North Korea. The purpose of this paper is to contribute to the activation of arbitration between South and North Korea by studying Commercial Arbitration Committee of South-North Korea introduced by Agreement on the Procedures to Resolve Commercial Arbitration of South-North Korea and Agreement on the Construction and Operation of Commercial Arbitration Committee of South-North Korea and finding the problems and solutions of Commercial Arbitration Committee of South-North Korea.

당뇨병성 신증 환자 20예에서 복합한약전탕액이 신기능에 미치는 영향

최우정,김동웅,신선호,이언정,최진영,신학수,조권일,이광석 대한동의생리학회,대한동의병리학회 2003 동의생리병리학회지 Vol.17 No.2

Diabetic Nephropathy is one of the major causes of chronic renal failure. It is a common microvascular complication and clinically defined as the presence of persistent Proteinuria. We studied the effects and change of the renal function of Complex Herbal medication of the 20Diabetic Nephropathy patients. We measured the initial levels of Total Protein, Creatinine Clearance Rate(Ccr), Serum Creatinine(Serum-Cr), Urine Creatinine(Urine-Cr) and HbA1C on admission and followed up the level changes of Total Protein, Ccr, Serum-Cr and Urine-Cr on discharge. The results are following : Complex Herbal Medication does not cause the renal toxicity. The longer hypertension period is, the higher Serum-Cr level and Urine-Cr level. In an older age group, Urine-Cr is lower. 4.From the "Deficiency in Origin and Excess in Superficiality(本虛表實)“points of view, Complex Herbal Medication improves the Serum-Cr in Diabetic Nephropathy patients. According to this results, it could be suggested that Complex Herbal Medication does not cause the renal toxicity in Diabetic Nephropathy patients and intensive controls of blood sugar, blood pressure and Complex Herbal Medication prevent the renal failure in Diabetic Nephropathy patients with early stage of Microalbumiuria.

멀티밴드 UWB 시스템의 무선성능 분석에 관한 연구

최석,김길겸,김학선 한밭대학교 정보통신전문대학원 2004 정보통신전문대학원 논문집 Vol.2 No.1

통신 시스템의 무선성능 요구조건 분석은 시스템의 성능을 예측하는 중요한 지표이다. 아직 표준안이 제정되지 않은 UWB(Ultra wide Band) 시스템은 명확한 시스템 성능 요구조건을 유포하기 어렵다. 또한, 기존 UWB 시스템과 멀티밴드 UWB 시스템의 무선성능 요구조건 분석에는 밴드 분할에 따른 무선 성능 요구조건의 도출상의 차이점이 있다. 이러한 차이점을 본 논문을 통해 분석하였으며, 이를 바탕으로 도출한 멀티밴드 UWB 시스템의 성능 요구조건을 본 논문에 기술하였다. 멀티밴드 UWB 시스템은 Sub-Band의 수에 따라 Throughput, 송 신 최대 전력, 수신감도 등이 변화하는 것을 관찰할 수 있었다. 또한, 멀티패스의 영향으로 PRE(Pu1se Repetition Frequency)를 감소시키면 Link Margin은 증가하여 멀티패스 에너지 손실(Multi-path Energy Loss)에 대한 보상으로 멀티패스 마진(Multi-path Link Margin)인 발생하는 것을 알 수 있었으며 멀티패스 마진에 따라 수신신호 감도 및 간섭신호에 대한 저항성이 변화하는 것을 모의실험을 통하여 분석하였다. The analysis of RF performance requirement conditions on communication system is critical indicator to predict the performance of system. UWB(Ultra Wide Band) system which the standard is not established yet is difficult to derive the precise system performance requirement condition. Also, there are differences between conventional UWB system and multi-band system about RF performance requirement condition. In this thesis, the differences are analyzed and performance requirement conditions of multi-band UWB system are described on the basis of the differences. Throughput, maximum transmit power, and sensitivity of multi-band UWB system is varied with respect to the number of Sub-Bands. In addition, because of Multi-path effect, if PRF(Pulse Repetition Frequency) is changed, the Multi-path link margin is happened to compensate for Multi-path Energy Loss which is contributed by increasing of the Link Margin. According to Multi-path Margin, the variation of the resistance with respect to sensitivity and interference signal is observed and analyzed through the simulation.

흉곽 내시경을 사용한 척추 기형 수술시 학습 곡선

김학선,최윤락,이환모,문성환,김경희,박진오,하중원,신동은 대한척추외과학회 2003 대한척추외과학회지 Vol.10 No.3

초광대역 무선 시스템 성능 분석에 관한 연구

김길겸,최석,김학선 한밭대학교 정보통신전문대학원 2003 정보통신전문대학원 논문집 Vol.1 No.1

본 논문에서는 UWB(Ultra WideBand) 시스템에 대한 성능 요구 조건을 미국연방통신위원회(FCC: Federal Communications Commission)에서 규정[1]한 주파수 대역(3.1 ~ 10.6GHz)에서 분석하였다. 실제 무선 통신 시스템의 설계를 위해서는 각 통신 시스템의 표준으로부터 시스템의 성능 요구 조건을 산출하는 것이 일반적이다. 그러나, UWB (Ulra WideBand) 시스템은 아직 표준이 정해져 있지 않다. 따라서 근거리 무선통신시스템(Indoor Communication Systems)의 분석 방법을 근간으로 하여 새로운 시스템 성능을 분석하여 각각의 시스템 파라미터를 도출하였다 아울러 국내의 법규[2]에 의한 성능을 도출하여 FCC에서 제시한 조건과의 차이를 비교하였다 The purpose of this paper is to analyze the performance requirements of wireless systems on ultra wide band, which is set by FCC(Federal Communications Commission). Normally the calculation of performance requirements is used in the standard form of each communication systems, but there is no standard in the wireless systems on Ultra WideBand. Therefore, I derive each system parameters through the analysis of new system performance on the basis of the method of Indoor Communication Systems. Additionally, I compare the conditions that are given by FCC with resolution of the performance by domestic law.

위암 환자의 복강내 투여를 위한 Activated Charcoal-Alginate Bead 제형으로부터 Mitomycin C의 용출 거동

이진호,최선웅,서중기,김동민,정경수,오정연,김진향,노승무,민병무,김용백,김창식,박근성,강대영,송규상,양준묵,조준식,정현용,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Locoregional recurrence is the most common type of recurrence in surgical operation of gastric adenocarcinoma, and peritoneal dissemination is one of the most difficult problems in advanced gastric adenocarcinoma treatment. Because the peritoneal cavity is the most common site of the first recurrence after gastric cancer resection, intraperitoneal chemotherapy seems a logical choice for cancer chemotherapy. In this study, Mitomycin C (MMC)-activated charcoal (CH)-alginate (ALG) beads were prepared by the mixtures of CH particles adsorbed with MMC as an anti-cancer drug and aqueous alginate solution. The alginate is recognized as biodegradable, nontoxic, and biocompatible. The release of MMC from the beads in 0.1 M Tris buffer was stable and continuous until about 1 week. The MMC-CH-ALG beads can be applied in the peritoneal cavity for intraperitoneal chemotherapy since they provide a good adhesiveness on the tissue and controlled release pattern of the drugs.

연약지반에 시공된 보강토 옹벽의 거동해석에 관한 연구

심태섭,최순범,김선학 朝鮮大學校 建設技術硏究所 2007 建設技術硏究 Vol.27 No.1

It was found that the factor of behavior in the retaining wall of reinforced earth on poor subsoil was influenced by load increment, consolidation time and pore-water pressure. Finite element analysis was conducted by using SAGECRISP program for the behavior analysis of poor subsoil and the retaining wall of reinforced earth in this theory. Firstly, the validity of replacement method was examined for the improvement of excessive displacement of the retaining wall of reinforced earth. Secondly, the influence in the ground behavior of the vertical space of reinforced materials on the back of retaining wall was analyzed. Lastly, the width and the depth of appropriate replacement in appling replacement method were suggested. As the result of this study, following conclusion was got. Replacement method take effect on the behavior improvement of the retaining wall of reinforced earth because the case of replacement method(width: 8m, depth: 5m) in the retaining wall of reinforced earth on poor subsoil shows that improvement effect of vertical displacement is 2 ~ 3cm in the upper direction. 7.5 ~ 26.2cm in the lower direction, 11.6 ~ 26.4cm in the vertical displacement on the back of retaing wall and 7.1 ~ 8.6% in shearing strain. The improvement of horizontal displacement was not great because △h_(h)/H maintained similar value despite the increase of replacement width.