• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.113-120
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• 2007

The 5kWt dish solar collector is designed and the preliminary performance test for this is carried out. The diameter of the parabolic dish is 3.2 m, and its focal length is 2 m. It consists of 10 small reflectors which have their own curvatures, and the effective reflecting area is $5.9\;m^2$, and the rim angle of the dish is $43.85^{\circ}$. The reflectivity of reflectors is 0.95, and the thermal capacity of the system is about 5 kW thermal. The aperture diameter of the cylindrical-shape receiver which is made of stainless steel is 100 mm, and the height is 210 mm. A quartz window is installed at the receiver aperture to minimize the convective heat loss and prevent air leakage. In order to increase the heat transfer area, porous materials (nickel-alloy) are inserted into the receiver. Air flows into the upper part of the receiver which is the opposite side of the aperture. After the air flows through the inside of the receiver, that goes out of the receiver through 3 exits which are located near the aperture. The volumetric flow rates of air are varied from 600 to 1200 L/min. The results show that the system efficiency and receiver efficiency increase as the volume flow rate increases.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.39.2-39
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• 1981

Recently, there has been many problems in the treatment of OMPC, because of inadequate and abuse of antibiotics, and resistant strain of pathogenic organisms to antibiotics. Authors studied on the culture and sensitivity of otorrhea obtained from 50 patients with OMPC, and evaluated the therapeutic effect of PPA, which is a new derivative of piromidic acid and active against gram (-) bacteria including pseudomonas aeruginosa as well as some gram (+) bacteria. We observed good therapeutic effect on OMPC with pseudomonas and other gram (-) bacteria, and considerable effect on OMPC with gram (+) bacteria.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.460-463
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• 2003

의료영상에서의 혈관의 분할은 심혈관계질환의 진단 및 시술을 위한 3차원 가시화 및 가상내시경을 하기위한 필수 선행 단계로 이에 대한 연구가 많이 이루어 지고 있다. 조영제를 투여한 환자의 CT데이터에서 혈관분할의 가장 큰 문제점은 혈관의 밝기값이 뼈의 밝기값과 비슷하기 때문에 기존의 3차원 SRG방법으로 분할하는 경우 새나감의 문제를 가지고 있었다. 본 논문에서는 Cubic SRG라는 방법을 통해 기존의 3차원 SRG가 가지는 깔끔한 분할결과와 적응적인 특성등의 여러 장점을 그대로 취하며 Cubic이라는 구조적 특징을 이용하여 혈관을 빠르고 강인하게 분할하는 방법을 제안한다. Cubic SRG는 SRG가 픽셀단위의 성장을 통해 동질 영역을 분할하는 방법을 사용함에 반해 Cubic이라는 부피 단위를 지정하여 이를 SRG의 픽셀과 같이 퍼트리는 방식으로 기존의 3차원 SRG에 비해 2$\sim$5배 정도의 빠른 수행속도를 보이며 3차원 SRG의 장점인 적응적인 특성을 그대로 가질수 있도륵 구현되었다. 또한 복셀들을 Cubic이라는 단위로 묶음으로서 혈관의 구조적인 분석을 수행하여 혈관을 트리형태의 구조로 그룹화가 가능하기 때문에 혈관을 가지별로 분할하기에 용이한 특징을 가지도록 하였으며, 이를 통해 새나감이 시작된 가지를 찾아서 잘라내는 방법을 통하여 SRG의 가장 큰 문제인 새나감 방법을 효과적으로 해결하는 방법을 제시한다. 최종적으로 위의 방법을 기본으로 하여 적응형 임계값 기반의 분할 방법을 혼합하여 사용자가 지정한 두 지점사이의 혈관을 강인하게 분할할수 있도록 구현하였고, 제안한 방법으로 여러 환자의 CT데이터에 실험하여 좋은 결과를 얻을 수 있었다.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.135-146
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• 2015

To provide the data necessary to determine the design wind speed for calculating the wind load acting on a greenhouse, we measured the wind speed below 10m height and analyzed the power law exponents at Buan and Gunwi. A wind speed greater than $5m{\cdot}s^{-1}$ is appropriate for calculating the power law exponent necessary to determine the wind speed distribution function according to height. We observed that the wind speed increased according to a power law function with increased height at Buan, showing a similar trend to the RDC and JGHA standards. Therefore, this result should be applied when determining the power law function for calculating the design wind speed of the greenhouse structure. The ordinary trend is that if terrain roughness increases the value of power law exponent also increases, but in the case of Gunwi the value of power law exponent was 0.06, which shows contrary value than that of the ordinary trend. This contrary trend was due to the elevations difference of 2m between tower installed and surrounding area, which cause contraction in streamline. The power law exponent started to decrease at 7 am, stopped decreasing and started to increase at 3 pm, and stopped increasing and remained constant at 12 pm at Buan. These changes correspond to the general change trends of the power law exponent. The calculated value of the shape parameter for Buan was 1.51, confirming that the wind characteristics at Buan, a reclaimed area near the coast, were similar to those of coastal areas in Jeju.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.2
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• pp.14-22
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• 1976

This research was started to develop a VHF television antenna which secures good pictures in spite of the disturbance from tile rear side. In a year of research, an antenna which front to banck ratio is gyrator than 30dB and whose side lobe level is smaller than -30dB alas been developed. This new antenna was designed log-periodically for the sake of wide frequency bandwidth which is necessary to cover all tile high channel. And it was found having characteristics of anti-interference against the disturbance wave from tole behind, and anti-ghosts from the reflected waves. Furthermore, the gain of this new antenna is reasonablly high, because of its low side lobe level. After all, the developed antenna is silpposcd to increace the service area considervably and to improve the TV receiving certainly.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.76-79
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• 2006

Primary malignant melanoma of the lung is extremely rare. A 46-year-old lady was admitted with two month history of dry cough and blood-tinged sputum. Chest CT showed 4.5 $\times$ 5.0 cm sized mass at the right lower lobe. Repeated bronchoscopic and percutaneous biopsies showed no definite diagnosis. Preoperative evaluations revealed no systemic metastais. So, we tried the surgical approach. Right lower lobectomy and lymph node dissection was done. The mass and lymph node were confirmed as primary malignant melanoma. The patient presented with right hemiparesis 40 days after operation. Brain MRI showed 1.5$\times$2.0 cm sized mass lesion on the left parietal lobe. Mass excision was done. However, she expired 8 months later.

• The Journal of Pediatrics of Korean Medicine
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• v.15 no.1
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• pp.261-265
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• 2001

소아의 소화성궤양은 소아 소화계질환 중에서 발병율이 점차 늘어나고 있는 추세에 있다. 최근 소아과에서 내시경의 활용이 활발해지면서 장기적으로 반복하여 위완통(胃脘痛), 변혈 (便血)및 구혈(嘔血)이 나타나는 경우 궤양성질환의 가능성이 높은 것으로 밝혀지고 있다. 본원에서는 유명한 중의사 왕붕비(王鵬飛) 교수의 비완통(脾脘痛) 치험방을 토대로 많은 임상을 거쳐 위평충제(胃平沖劑)를 개발하여 1992년6월부터 1997년12월까지 위내시경 검사를 통하여 위궤양으로 진단된 98명의 소아환자에게 투여하여 관찰한 바 만족스러운 효과가 나타나 이를 보고한다. 위평충제(胃平衝劑)의 처방구성은 자초(紫草), 청대(靑黛), 곽향(藿香), 유향(乳香), 회향(茴香), 정향(丁香), 황련(黃連), 적석지(赤石脂), 황정(黃精) 등이다. 한의학적 이론에 따르면 불규칙하고 자극성이 강한 음식섭취 습관은 비위(脾胃)를 손상시켜 중주(中州)를 옹체(壅滯)시키므로 기(氣)의 원활한 소통이 이루어지지 않으면 부통즉통(不通卽痛)의 기전으로 발전한다. 또한 근래 소아들이 각종 정신적인 압박으로 스트레스가 쌓이면서 간기울결(肝氣鬱結)을 초래하여 울화(鬱火)로 인하여 혈락(血絡)이 손상되면서 출혈증상이 나타난다. 왕교수의 견해에 따르면 체내에 어혈이 제거되지 않으면 기혈(氣血)의 순환이 더욱 악화되어 어적(瘀積)이나 궤양 또는 경새(梗塞) 등을 일으키게 된다고 하였다. 따라서 위평충제(胃平沖劑)는 활혈화어(活血化瘀), 청열해독(淸熱解毒)과 더불어 익기양위(益氣養胃), 거어지통(祛瘀止痛)의 효능이 있는 약물들로 구성되었다. 동물실험에서 위평충제(胃平衝劑)는 궤양표면을 보호하고 치유하며 재발을 방지하는 효과가 있는 것으로 확인되었고, 위액의 분비, 위단백질효소의 활성에 대한 억제 및 진통효과도 있는 것으로 입증되었다.행하여 사용하는 것이 바람직하며, 단순한 중약 투여는 일부 양약에 의한 소아성장에 미치는 영향을 피할 수 있어 더 많은 임상연구가 이어져야 한다.(當歸) 목단피(牧丹皮) 울김(鬱金) 정력자(?歷子) 세신(細辛) 오미자(五味子) 구기자(枸杞子) 산수황육(山茱黃肉) 황기(黃?) 감초(甘草) 등을 기본적으로 사용한다. 비신양허형(脾腎陽虛型)은 온보비신(溫補脾腎) 화어척담(化瘀滌痰)을 원칙으로 하며, 처방에는 구마황( 灸麻黃) 세신(細辛) 오미자(五味子) 당귀(當歸) 단삼(丹蔘) 울김(鬱金) 정력자(?歷子) 반하(半夏) 보골지(補骨脂) 선령비(仙靈脾) 태자삼(太子蔘) 황기(黃?) 감초(甘草) 등을 기본적으로 사용한다. 치험(治驗): (1) 천식의 실증(實證)은 치료를 한 뒤 완화단계에 접어들면서 허증(虛證)으로 전화되는데, 허천(虛喘)도 역시 천식이니 만큼 단순히 보법(補法)만 사용하여서는 안된다. 시종일관 천식치료에는 척담화어(滌痰化瘀)의 원칙을 지켜야 한다. 폐내(肺內)의 담어(痰瘀)가 철저하게 제거되어야 폐(肺)의 순환기능을 개선시켜 기도(氣道)의 염증을 신속히 흡수하고 치유할 수 있다. 이와 같은 치료과정은 약 3-6개월이 필요하다. 완화단계의 기간이 길어질수록 완치될 확률도 높아진다. (2) 급성기 천식은 폐(肺)를 다스려야 한다. 폐(肺)를 다스리는 방법에는 선폐(宣肺), 청폐(淸肺), 온폐(溫肺), 윤폐(潤肺) 및 척담거어(滌痰祛瘀) 등이 있다. (3) 증상이 완화되면 신(腎)을 다스린다. 천식은 신허(腎虛)가 근본적인 원인이므로 완화단계에서 심지어 발작기에도 보신제(補腎劑)를 추가하여 사용하면 배의 효과를 얻을 수 있다. (4) 비(脾)의 기능을 강화하여 근본을 채우는 부비배본(扶脾培本)도 중요하다. 후천의 수곡정미(水穀精微)로 선천을 충족시키고 자양하는 것은 질병에 대한 저항력을

• Korean Journal of Optics and Photonics
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• v.32 no.2
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• pp.68-78
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• 2021

A subminiature catadioptric omnidirectional optical system (SCOOS) with 2 mirrors, 6 plastic aspherical lenses, and an illumination system of 6 light emitting diodes, to observe the 360° panoramic image of the inner intestine, is optically designed and evaluated for a capsule endoscope. The total length, overall length, half field of view (HFOV), and F-number of the SCOOS are 14.3 mm, 8.93 mm, 51°~120°, and 3.5, respectively. The optical system has a complementary metal-oxide-semiconductor sensor with 0.1 megapixels, and an illumination system of 6 light-emitting diodes (LEDs) with 0.25 lm to illuminate on the 360° side view of the intestine along the optical axis. As a result, the spatial frequency at the modulation transfer function (MTF) of 0.3, the depth of focus, and the cumulative probability of tolerance at the Nyquist frequency of 44 lp/mm and MTF of 0.3 of the optimized optical system are obtained as 130 lp/mm, -0.097 mm to +0.076 mm, and 90.5%, respectively. Additionally, the simulated illuminance of the LED illumination system at the inner surface of the intestine within HFOV, at a distance of 15.0 mm from the optical axis, is from a minimum of 315 lx to a maximum of 725 lx, which is a sufficient illumination and visibility.

• Journal of Gastric Cancer
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• v.4 no.4
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• pp.242-251
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• 2004

Purpose: Recently, because of the increasing numbers of early gastric cancer patients and improvements in their survivals, greater attention has been directed towards the quality of life and nutritional status of gastric cancer patients after surgery. However, conventional reconstructions, Billroth- I, -II (B-I and B-II) or Roux-en-Y, have proven to have certain limitations, such as a small reservoir, and a malabsorption for iron, fat, calcium, and carotene. To overcome these limitations, we used a jejunal pouch interposition(JPI) after a distal gastrectomy not only to substitute for the small reservoir but also to maintain a physiologic pathway for ingested foods. Materials and Methods: A total of 196 gastric cancer patients who underwent a distal gastrectomy between March 2001 and February 2004 were divided into 3 groups: JPI group (n=100), B-I group (n=29), and B-II group (n=67). We assessed the patient's nutritional status, gastric emptying time, and gastrofiberscopic findings. Results: The percents of body weight loss at 6 months, 1 year, and 2 years postoperatively in the JPI group ($5.14\%,\;3.01\%,\;2.37\%$) were significantly less than those of the conventional B-I ($8.41\%,\;6.69\%,\;5.90\%$) and B-II groups ($7.50\%,\;7.65\%,\;5.86\%$) (P=0.011, 0.000, 0.013). The laboratory findings showed no significant differences between the 3 groups, except for a higher total protein level in the JPI group after 6 months postoperatively. Especially, stage I and II cancers in the JPI group showed much higher total protein levels after 1 year postoperatively. The gastric emptying times in the $\^{99m}$Tc- semisolid scans at 6 months, 1 year, and 2 years postoperatively were 102.5, 83.1, and 58.1 minutes in the JPI group, 95.5, 92.0, and 58.5 minutes in the B-I group, and 53.9, 69.1, and 50.2 minutes in the B-II group, respectively. Also, the symptomatic gastric stasis detected with a gastrofiberscope during the early postoperative period (6 months) was gradually improved. Conclusion: From a nutritional aspect, a jejunal pouch interposition after a distal gastrectomy could be an alternative reconstruction method, especially in stage I and II gastric cancer patients, in spite of the longer operation time and the probable delayed gastric emptying.

• Tuberculosis and Respiratory Diseases
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• v.53 no.4
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• pp.431-438
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• 2002

Background : In order to investigate the usefulness and safety of Natural Stent, we performed this study in a canine model of tracheal stenosis induced using Nd-YAG laser. Materials and Methods : After tracheal stenosis was induced in 12 Mongrel dogs using Nd-YAG laser, either Dumon (n=6) or Natural (n=6) stent was inserted into the trachea. To assess the degree of stent migration and mucostasis, bronchoscopy was performed every week for 4 weeks, after which all stents were removed. One week after stent removal, tracheal stenosis was evaluated by bronchoscopy. Results : The degree of stent migration was not different between the dogs with Dumon stent ($3.0{\pm}0.8$) and those with Natural ($2.0{\pm}1.0$), nor was the degree of mucostasis, at Dumon ($1.7{\pm}0.5$) and Natural Stent ($1.5{\pm}0.6$), respectively. One week after stent removal, the degree of tracheal stenosis was not different between the Dumon ($1.5{\pm}0.5$) and the Natural group ($1.0{\pm}0.4$). In addition, there was no death and the degree of tracheal stenosis remained always within the safe limit (less than 2.0) in all animals. Conclusion : In a canine model of tracheal stenosis induced using Nd-YAG laser, the usefulness and safety of Natural Stent were similar to those of Dumon Stent. A clinical trial is necessary to document the usefulness and safety of Natural Stent in patients with tracheal stenosis.