대량 출혈을 유발한 공장게실 1예

전정현,이선영,이나란히,신정은,주미순,정성애,한호성,유권 梨花女子大學校 醫科大學 醫科學硏究所 2001 EMJ (Ewha medical journal) Vol.24 No.1

A case of massive intestinal bleeding from jejunal diverticulum is describe. A 62-year-old man was refered to our hospital because of melena and anemia. After admission, he showed massive hematochezia with unstable vital sign. Esophagogastroduodenocopy and colonoscopy, selective abdominal angiography, and RBC bleeding scanning were performed to seek the cause of the intestinal bleeding, but none of these studies revealed the source of bleeding. The examination of small bowel with methylcellulose showed multiple small jejunal diverticuli and a large diverticulum. Resection of the involved portion of jejunum was performed. On pathological examination, two mucosal loss lesions were detected, but ulcer or arteriovenous malformation were not seen in the resected jejunal diverticulum. The patient showed no more intestinal bleeding after operation. Although jejunal diverticuli are rare, the careful search for this complication in a patient with intestinal bleding is important.

ATM망에서 ABR서비스를 위한 효율적인 전송률 할당 알고리즘에 관한 연구

천재호,윤상호,김명균,허정석 울산대학교 1999 공학연구논문집 Vol.30 No.2

ATM망에서 ABR 서비스는 CBR, VBR에 할당된 대역폭을 제외한 나머지를 이용해서 데이터를 전송한다. 오디오 또는 비디오 데이터와 같이 실시간 전송이 필요한 서비스들을 전송지연이 제한되는 CBR이나 VBR 트래픽을 이용하여 제공할 수 있지만, 이런 경우에는 전송 대역폭을 효율적으로 사용하지 못하는 단점이 있다. 본 논문에서는 실시간 데이터를 ABR 서비스를 이용하여 효율적으로 전송하기 위한 ABR 대역폭 할당 알고리즘을 제안한다. 제안된 알고리즘은 MCR을 보장하며, MCR에 비례해 전송률을 할당한다. 그리고 접속의 상태를 만족(satisfied)상태와 불만족(bottlenecked)상태로 구분하고, 만족 상태인 접속이 사용하지 않는 대역폭을 불만족 상태인 접속이 사용할 수 있도록 하여 대역폭 활용도를 높인다. 또한 제안된 알고리즘은 큐 제어 함수를 사용해서 큐 길이를 일정한 범위로 유지함으로써 셀의 전송지연을 일정하게 한다. 본 논문에서는 시뮬레이션을 통해 제안된 알고리즘의 성능을 분석하고, 기존에 제안된 ATM 포럼[1]및 Kalampoukas 알고리즘[2]과 비교를 하였다. On ATM networks, ABR services are provided using the remained bandwidth after allocating CBR and VBR traffic. Realtime services such as transmitting audio or video data may be provided using CBR and VBR which have a constrained transmission delay, but in those cases, the communications bandwidth may be wasted. This paper proposes an efficient ABR rate allocation algorithm to transfer real-time data using ABR service. The proposing algorithm guarantees MCR and allocates bandwidth to each connection proportional to its MCR. The proposing algorithm divides the connections in two groups, a satisfied state group and a bottlenecked state group, and enhances bandwidth utilization by allowing the remained bandwidth after allocating to the connections in the satisfied state to the connections in the bottlenecked state. The proposing algorithm uses the queue control function to keep the queue length within some boundary, which makes the transmission delay constant. We simulate and compare the performance of the proposing algorithm with that of the algorithms proposed by ATM Forum[1] and Kalampoukas[2].

주제공원 방문객의 선택행동에 관한 연구

전가환 ; 김상희 김천대학교 2000 김천대학교 논문집 Vol.21 No.-

This study was undertaken because we wanter to present the mar-keting suggestions which make service strategies for the customers. This paper tries to find out major choice attribute on Theme Park when the customer takes a visiting. The study sought to segment users of the theme park and investi-gate their behavioral characteristics. For the purpose of this study, we used the theme park selection attributions as variables of mar-ket segmentation. The sample was the users of Expo Science Park in Taejon. Korea The data for this study were collected from a questionnaire survey 456 visitors.​

유도 전동기를 위한 자기 동조 퍼지 제어기 설계

전광호,하남수,박준열,김상윤 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.2

The conventional PI control, that are used in the control loop for outer speed of the induction motor, also has difficulty dealing with the dynamic speed tracking, parameter variation, and the load disturbance. As a result, the motion control system operates with a poor performance in the motor´s low speed range. In this paper, a novel speed control system that implements the fuzzy logic controller(FLC) is proposed. The proposed FLC used the speed error, its rate of change, and the drive current as three fuzzy variables. The real command output current is chosen by the defuzzification of the fuzzy output extracted from the fuzzy control rules. The flux and the torque of the induction motor are estimated using the dynamic model with an excellent dynamic response over a wide speed range and with the rotor flux field-oriented scheme of the decoupling characteristics. The performance of this control system is substantiated by computer simulations.

VOC와 EC의 공통 속성에 관한 연구

전영호,박성현 弘益大學校 科學基術硏究所 1999 科學技術硏究論文集 Vol.10 No.2

비자의 요구사항은 구체적으로 표현되기 보다는 추상적으로 표현된다는 것이 일반적이다. 따라 소비자의 요구사항을 제품의 설계특성에 직접적으로 연관짓는다는 것은 결코 쉬운 일이 아니다. 연구에서는 제품에 대한 소비자의 요구사항과 설계특성간의 공통요인인 Attribute을 추출 및 활여 양자간의 Relationships Matrix를 구축하는 프로세스를 다루고자 한다. 특히, Relationshipsix는 소비자 요구사항인 VOC, 설계특성인 EC 및 공통요인인 Attribute의 DB를 구축한 후 품질전개(Quality Functin Deployment; QFD)의 핵심인 품질의 집(House of Quality; HOQ)의 형태로 되어 제품 개발의 추후 단계에 활용할 수 있도록 하고자 한다.

다공질 금속재료의 흡음성능 평가

전종균,엄호성 선문대학교 중소기업기술지원연구소 2001 선문공대 연구/기술 논문집 Vol.6 No.1

소음이란 공기의 진동에 의한 음파중에서 가청적인 것으로서 인간이 감각적으로 바람직하지 않다고 느껴지는 소리이다. 이러한 소음저감을 위해 사용되는 물질중 하나가 다공질 금속 재료이며, 이것은 에너지 흡수재로 많이 사용되고 있는 균일한 셀(cell)형태 구조의 기공을 가진 물질이다. 고체 소재와는 다른 다양한 물질의 특성으로 인하여 매우 특별하면서도 다양한 용도로 사용되고 있다. 본 논문에서는 다공질 금속 재료를 이용한 흡음재를 연구하였다. 압축기(compressor)에서 나오는 공기의 압력을 오피리스(orifice)에서 단계적으로 조절하고, 시험편과 마이크로폰을 적절히 배치하여 주파수 분석기로 흡음성능을 확인하였다. Noise generated by the vibration of air in the range of hearing frequencies is undesirable for human sense. The porous metal is one of the sound absorbing materials and in structure it has homogeneous cell in which the energy would be dissipated throughout. Since it also has various material characteristics compared with solid materials, it could be used for specific purpose. In this paper, sound absorbing material has been investigated by using the porous material. The efficiency for sound absorbing materials by frequency analyzer has been verified by the experiments in which the air pressure from the compressor is controlled step by step at the orifice and specimen and microphone are arranged accordingly.

고정상세포분리기의 개발 및 Cyclosporin A 생산을 위한 고정화 연속배양공정에의 적용

이태호,박성관,장용근,전계택 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.6

균사형성 미생물인 고정상곰팡이의 연속배양공정에 필수적인 효율적인 고정상세포분리기를 개발하고 이를 실제로 면역억제제인 cyclosporin A(CyA) 연속생산공정에 적용하였다. 점성이 큰 고분자인 carboxymethyl cellulose 용액을 이용한 실험에서 개발된 고정상 세포분리기는 분리능이 우수하여 고점도·고유속의 경우에도 고정성담체가 거의 유실되지 않았다. 이는 고정상세포분리기내에 설치된 공기유출관과 분리관의 역할에 기인하는 것으로 보인다. 또한 실제 곰팡이 세포를 이용한 고정상 연속배양(IPRS)의 경우 고정상세포분리기를 설치함으로써 담체밀도의 감소와 배양액내의 고농도(10g/l) 현탁 곰팡이 세포의 존재에도 불구하고 안정한 조업가능성을 보였다. 고정상 연속배양의 높은 희석속도에도 불구하고 균체 및 CyA의 생산성이 높게 나타났으며, 담체가 반응기 밖으로 거의 유출되지 않은 점으로 보아 고정상세포분리기의 우수한 성능 및 조업안정성을 확인할 수 있었다. We have developed an efficient immobilized cell separator for continuous operation of immobilized fungal cell cultures, and applied this separator to actual fermentation process for the production of cyclosporin A (CyA), a powerful immunosuppressant. In the experiments employing highly viscous polymer (carboxymethyl cellulose) solution, the decantor showed good separating performances at high solution viscosites and fast dilution rates. Air duct and cylindrical separator installed inside the decantor turned out to play key roles for the efficient separation of the immobilized cells. By installing the decantor in an immobilized perfusion reactor system (IPRS), continuous immobilized culture was stably carried out even at high dilution rate for a long period, leading to high productivities of free cells and CyA. Almost no immobilized biomass existed in effuluent stream of the IPRS, demonstrating the effectiveness of the decantor system for a long-term continuous fermentation. It was noteworthy that we could obtain these results despite of the unfavorable fermentation conditions, i.e., reduced density of the biosupports caused by overgrowth of cells inside the bead particles and existence of high density of suspended fungal ells (10 g/l) in the fermentation broth.

청소년의 부모폭행에 대한 연구

이호분,전여숙,민성길,오강섭,이시형 대한소아ㆍ청소년정신의학회 1997 소아청소년정신의학 Vol.8 No.2

고정성 Resin-bonded bridge를 이용한 상실된 유전치부의 심미 수복 : 증례보고 Case reports

박인천,박성규,위유민,이봉규,김효석,이상호 조선대학교 구강생물학연구소 2002 口腔生物學硏究 Vol.26 No.2

Today's parents are quite conscious of the esthetic and Potential psychological consequences of missing anterior teeth. Premature lobs of Primary incisors usually dose not require the Placement appliances for space maintenance because no mesial movement of the adjacent teeth is normally expected when the canines have already erupted. However, replacement of anterior teeth may be indicated for esthetic purposes or possibly to facilitate normal pronunciation. The treatment options in these cases are removable maintainers of space or fixed partial dentures, the former being most often used. When no cooperation on the part of the patient for their used or when the devices provoke discomfort or atypical glutition, fixed partial dentures may be used, taking into consideration premaxillary growth.

일반주거환경이 기관지과민성에 미치는 영향

김상섭,전형준,백도명,김록호,김호 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.2

Objectives : The increased prevalence of asthma over the last 30 years has been reported from many different countries, including Korea. The increased prevalence may be due to increased exposure to indoor air pollutants. Methods : In this study, the relationship between residential environments and airway hyper-responsiveness has been examined among 280 family members. The bronchial hyper-responsiveness was expressed as the log-transformed slope of FEV1 decrease over the log-transformed dose of methacholine concentration (BRindex). Simple regression analysis was done for the effect of sex, age, atopic status, and residential environments including active and passive smoking exposures on airway responsiveness. Based on simple regression results, multiple rwegression analysis was performed for total group and also according to sex. Results : The mean of BRindex of residents living in gas boiler heating houses was higher than that of central heating system (p=0.014). Smoking status was a significant determinant of bronchial hyper-responsiveness in both genders, male (p=0.017), female (p=0.022). In the male group the mean of BRindex of current smokers was significantly higher than those of ex-smokers and non-smokers, and the mean of BRindex of passive smokers was higher than that of non-smokers, but statistical significance was border-line(p=0.069). In female group, the mean of BRindex of kerosene stove users was higher than that of non-users (p=0.057). Conclusions : This study suggests that indoor air pollutants including type of heating, passive smoking and kerosene stove use can contribute to the increase in asthma prevalence in Korea.