소출력 송수신기용 광대역 안테나 개발

전중창,한수용 진주산업대학교 산업과학기술연구소 2007 산업과학기술연구소보 Vol.- No.14

As the wireless services are popular for convenience, antennas having wider bandwidth are required more often. In this paper, a new type of monopole antenna is invented for multiple band applications. Multiple band property for the proposed antenna is achieved by adjusting the coupling structure of the antenna base. -10 dB impedance bandwidths are 1.74-3.06 GHz and 5.59-10.62 GHz, which can cover various kinds of wireless services, such as PCS(1.75-1.87 GHz), IMT-2000(1.92-2.17 GHz), WiBro(2.3-2.39 GHz), WLAN (2.412-2.483 GHz, 5.725-5.825 GHz), DMB(2.63-2.655 GHz), High-band UWB(7.2-10.2 GHz).

유전율이 다른 두 기판의 접합에 의한 마이크로스트립 불연속의 반사특성 해석

전중창,김태수,한수용 위덕대학교 산업기술연구소 2001 산업기술연구소 논문집 Vol.5 No.1

The finite-difference time-domain (FDTD) method has been applied to the analysis of microstrip discontinuities comprised of junctions of two substrates having different dielectric constants. The discontinuities treated in this paper include microstrip step-in-width on a single substrate for the validation of analysis method, and microstrip junctions of two different substrates where strip widths are varied to analyze the reflection characteristics numerically. It is noted that the result for the junction having a uniform strip width but different dielectric constants shows a similar characteristic with a conventional step-in-width discontinuity. The importance of this result is the implication that the junctions treated in this paper can be applied to the design of microwave passive circuits such as filters and matching networks.

흰쥐 삼차신경 척수감각핵의 미측소핵 세포의 전압의존성 소디움통로와 포타슘통로에 대한 전기생리학적 연구

천상우,최정희,김권수,유용묵,김종구,이동근 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.1

The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn ; MDH) receives direct inputs from unmyelinated and thinly myelinated, small diameter primary afferent fibers. Thus, the MDH is implicated in the processing of nociceptive information in the orofacial region. In this study, the types and characteristics of voltage-dependent ion currents were investigated in acutely isolated MDH neurons of postnatal rats by means of the whole cell patch clamp techniques. Coronal slice (400㎛) of the trigeminal caudal subnucleus region was sequentially treated with pronase 0.2㎎/㎖. then single neurons were mechanically dissociated. Voltage-dependent sodium currents showed that the half-maximum activation potential was -41.8±1.8mV and half-maximum inactivation potential was -62.4±3.0mV. And the currents were blocked totally by application of 100nM tetrodotoxin. In a Ca^2+ free solution, low-threshold transient (I_A) and high-threshold sustained (I_K) currents were recorded. The half-maximum activation and inactivation potential of I_K were 2.5±1.9mV and -37.1±2.3mV, respectively. I_A was activated and inactivated more rapidly than I_K. The half-maximum activation and inactivation potential were -21.6±6.3mV and -84.5±5.0mV, respectively. When a 4-aminopyridine of 5mM was applied, I_A was almost totally blocked. These results reveal that MDH neurons express a variety of voltage-dependent ionic currents with distinct physiological and pharmacological properties, and they play an essential role in the transmission and modulation of sensation, especially pain, from trigeminal region.

요추 Y-각 협착증 : 요추간 협착증의 새로운 개념 New Concept of Lumbar Stenosis

김영수,조용은,박형천,윤도흠,노성우 대한신경외과학회 1993 Journal of Korean neurosurgical society Vol.22 No.1

Authors measured the Y-shaped angle made by both yellow ligaments and both laminae named Y-angle at the spinal CT scan in normal and lumbar stenosis group. The normal range of Y-angle is between 60˚and 95˚. Lumbar stenosis is classified into narrow Y-angle stenosis(<60°) and wide Y-angle stenosis(>95°) by Y-angle. Narrow Y-angle stenosis is most common in degenerative spondylotic stenosis. Wide Y-angle is most common in congenital stenosis. The Y-angle is a simple and useful diagnostic indicator in the diagnosis of lumbar spinal stenosis on CT scan and MEU scan.

원격탐사 데이터의 분석을 통한 레이다 클러터 모델 연구

이용택,전중창,김태수 위덕대학교 부설 전자기술연구소 1999 전자기술연구소 논문집 : 위덕대 Vol.3 No.1

본 논문에서는 주파수, 입사각, 전파 편향 등에 따른 클러터 데이터를 수집하고 이를 바탕으로, 이론적, 실험적 클러터 모델과 원격탐사 모델을 비교 분석하였다. 그리고 육지와 바다에 대한 원격탐사 모델을 클러터 영역으로 extrapolation하여 클러터 모델로의 적용 가능성을 제시하였다. 검토된 원격탐사 모델 중에서 선형적 데이터 피팅 특성을 갖는 Moore 모델은 low grazing angle에서 세부 표적별로 상세한 클러터 특성을 예측하는데 사용될 수 있으며, 해양에서는 균일한 바다 특성으로 인하여 그대로 사용될 수 있음을 보였다. 원격탐사 데이터베이스를 클러터 영역까지 적용하기 위해서는 단순한 data-fitting만으로는 불충분하며, 지구 곡률 반경의 영향, 지형 거칠기 효과, 대기 상태 등의 물리적 해석이 뒷받침되어야 한다. In this paper, we have comparatively analysed the radar clutter models and remote sensing models based on the collection of available remote sensing data base. The possibility of extrapolation of remote sensing models onto the radar clutter region is presented to obtain simplified clutter models, taking the advantage of abundant data base of remote sensing field. Moore model, linear data-fitting model, is found to be used in predicting clutter characteristics for detailed land targets and ocean clutter return even in low grazing angle. The application of remote sensing models for radar clutter models requires the explanation of various physical effects of, for examples, the earth curvature, earth roughness, the state of atmosphere.

몇 種의 熱帶産蘭種子의 無菌培養에 관한 硏究 : (Effect of Activated Charcoal, Sucrose and Plant Growth Regulator Concentration on Germination and Growth) 1.活性炭, 糖濃度, 植物生長調節劑의 濃度가 發芽와 生育에 미치는 影響

李春容,蔡洙天 公州大學校 資源科學硏究所 1993 資源科學硏究論文集 Vol.1 No.-

This study was conducted to detemine the optimal basal media, activated charcoal, sucrose and plant growth regulator of concentration far germinagion and growth of Cattleya and Dendrobium. The results obtained were summarized as follow; 1. The germingtion and growth of Cattleya were the best in the MS medium supplemented with 0.3% activated charcoal but the Dendrobium were the best in the MS medium not supplemented with activated charcoal. 2. The germination and growth of Cattleya and Dendrobium were the best in the MS medium supplemented with 3 to 5 perecnt sucroce. 3. The germination and growth of Catteya and Dendrobium were the best in the MS medium supplemented with 1.0 ppm NAA, shoot formation was the best in the basal MS medium supplemented with 10 ppm BA and 1.0 ppm NAA and root formation was the best 1.0 ppm BA and 10 ppm NAA.

유전율이 다른 두 마이크로스트립 기판 접합에 의한 불연속의 해석 : 3차원 유한차분-시간영역 방법에 의한 접근

이용택,전중창,심재륜,김태수 위덕대학교 부설 전자기술연구소 1999 전자기술연구소 논문집 : 위덕대 Vol.3 No.1

본 논문에서는 3차원 유한차분 시간영역 방법을 사용하여 유전율이 서로 다른 마이크로스트립 기판의 접합 불연속 효과를 해석하였다. 본 논문에서 구현된 FDTD 알고리듬의 정확성을 검증하기 위해서, step-in-width 불연속 해석 결과를 상용 CAD 소프트웨어 시뮬레이션 결과와 비교였으며, 18 GHz까지의 주파수 범위에서 두 결과가 잘 일치하였다. 유전율이 서로 다르더라도 특성 임피던스가 동일하도록 도체 폭이 조절되면 반사계수가 -33 dB이하로 매우 낮아지며, 유전율이 서로 다르면서 도체 폭이 균일 한 경우에는 step-in-width 불연속 효과와 비슷한 결과가 얻어졌다. 유전율이 서로 다른 마이크로스트립 기판 접합에 의한 불연속 효과는 마이크로파 회로 모듈 패키징(packaging), 안테나 피더(feeder) 등의 설계에 적용될 수 있다. In this paper, we have analysed the junction of microstrip substrates having different permittivities using the 3-dimensional finite-difference time-domain (FDTD) method The accuracy of the FDTD application is validated by the comparison between FDTD results and commercial CAD software simulation results for a conventional step-in-width discontinuity. The FDTD results for the junction of microstrip substrates having different permittivities reveal that the reflection coefficient can be very small as below -33 dB only if the widths of metal strips are adjusted so that characteristic impedances of both sides are uniform. Also, it is shown that the junction with a uniform strip width has a similar characteristics as a step-in-width discontinuity. The simulation results presented at this paper can be applied to microwave circuit packaging and antenna feeder circuits.

익수환아의 예후에 영향을 미치는 인자에 관한 연구

김용배,정대봉,조수형,조남수,박영봉,박상기,김춘호,양은석,문경래 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.3

Drowning is the second most common cause of accidental death of children in Korea. But the study of near-drowning is very rare in Korea. The purpose of our study is to determine the factors that may influence survival on the basis of submersion time, consciousness state upon admission to hospital, the kinds of water, laboratory findings and neurological outcomes. The survey was performed by a retrospective cohort study on 28 near-drowning victims of less than 15 years of age who were admitted to the emergency room in the Chosun University Hospital between May 1988 & May 1997. The results were as follows :1)Sex distribution was 22 males and 6 females. 2) Submersion time was <5 minutes in 9 cases, 5-9 minutes in 6 cases, 10-14 minutes in 5cases, 15-19 minutes in 3 cases, ≥20 minutes in 5cases. 3) Comatose patients upon arrival were 6/7 cases in the death group(86%) and 2/21 cases in the improved group(10%). They had unfavorable outcomes(P<0.05). 4) The first PH value was mean 7.02±0.12 in the death group and mean 7.31±0.13 in the improved group. There was a statistically significant difference between the death and the improved group(P<0.05) 5) The patients who gad increased blood glucose concentration were all 7 cases in the death group and 12/22 cases in the improved group(54%). The mean blood glucose concentration was mean 424.7235.6㎎/㎗ in the death group and mean 140.182.7㎎/㎗ in the improved group. There was a statistically significant difference between the death and the improved group(P<0.05). 6) The patients who had pulmonary edema upon arrival were all 7 cases in the death group and 1/21 cases in the improved group(46%). They had unfavorable outcomes(P<0.05). 7) The patients who had been submerged more than 15 minutes were all 7 cases in the death group and 6/21 cases in the improved group(5%). They had unfavorable outcomes(P<0.05). We conclude that pediatric victims of near-drowning can be assigned to high or low likelihoods of unfavorable our outcomes with the use of five variables ; comatose mentation upon arrival decreased initial blood pH, increased initial blood glucose concentration, pulmonary edema, and maximum submersion time estimated longer than fiften minutes. This prediction rule may be useful if it can be validated in another cohort.

강진만에서 미생물의 년 변화

박종천,오재영,정용욱,주현수,이원교,유춘만,이우범 國立 麗水大學校 환경문제硏究所 2001 環境硏究論文集 Vol.4 No.-

The biological surveys were performed at seven sites in the Gangjin bay from February, 1998 to November, 2001. In order to analysis of environmental variation, numbers of heterotrophic bacteria, general fungus and fecal coliforms were enumerated in each sample. The result showed that variation range of heterotrophic bacteria, general fungus, and fecal coliforms were 2.9 x 10^(3)~9.6 x 10^(3) CFU/ml, 17.2~80.1 CFU/ml, and 6.3~682.5 CFU/100ml for four tears(1988~2001), respectively. Density of heterotrophic bacteria and general fungus were gradually decreased for four tours, while fecal coliforms were suddenly increased. Specially, numbers of fecal colifoms were increased the more 100 times in 2001 than that 1998. We think that it was probably caused a little rainfall in February, 2001. There result suggests that ecosystem of Gangjin bay were mainly regulated by 2~3 factors, which were inflow of fresh water, salinity and variation of water temperature.

Thermal MOCVD와 DC pulsed PA-MOCVD에 의해 증착된 TiN 박막 연구

박용균,이영섭,이태수,이성재,조동율,천희곤 울산대학교 2001 공학연구논문집 Vol.32 No.1

유기화합물(TDEAT;Ti[N(C2H5)2]4)과 NH3를 이용하여 thermal MOCVD와 dc pulsed plasma assisted MOCVD(PA-MOCVD)인 2종류의 TiN박막을 증착하여 비교하였다. TiN박막의 특성분석은 XRD, AES, FE-SEM, α-step과 XPS로 연구하였다. DC pulsed plasma assisted MOCVD로 증착된 Tin박막은 ion bombardment 효과에 의해 열적으로 증착된 것보다 더 fine한 columnar구조를 나타내므로써 막의 결정질이 향상되었다. 플라즈마에서의 아르곤 이온의 충돌로 인해 탄소(C)는 오히려 유기 화합물보다 탄소 라디칼로 존재하였다. 따라서 탄소 라디갈은 기판의 강한 (-) potential에 의해 TiN박막에 trap되기 때문에 탄소(C)는 열적으로 증착된 TiN박막보다 더 많은 양이 존재하는 것으로 추정된다. By using of (TDEAT;Ti[N(C2H5)2]4)and ammonia gas source, we deposited two different TiN thin films with thermal MOCVD and dc pulsed plasma assisted MOCVD (PA-MOCVB). The properties of TiN thin films were studied by XRD, AES, FE - SEM, α - step and XPS analyses in this work. The TiN films deposited by dc pulsed PA - MOCVD have a little higher density and a fine columnar structure, compared with thermally deposited TiN thin films. This may be due to ion bombardment effect resulting in improved crystallinity in films. Carbon in the film may exist in the form of carbonic radical rather than organic compound because of collision with Ar ion in the plasma. Consequently, the content of carbon in the film of dc pulsed PA - MOCVD was higher than that in thermally deposited TiN films, because carbon radicals could be trapped in the film by strong negative potential of the substrate.