Al-Si합금용탕과 Al₂O₃의 젖음성에 관한 연구

朴昌宣,金鍾贊,朴相俊,權赫茂 忠南大學校 産業技術硏究所 1992 산업기술연구논문집 Vol.7 No.1

The purpose of this study is to obtain basic infotmation on the wettability of pure-Al/Al₂O₃, Al-alloy/Cu, Al-alloy/Ni and Al-12%Si/Al₂O₃systems, by using the Sessile drop method. The wettability of Al alloy-melt on Al₂O₃increases with increasing temperature from 750℃ to 850℃ for Al-12%Si-y% (Cu, Zn and Mg) (y:0∼2)/Al₂O₃system, the contact angle decreases with increasing Cu, Zn and Mg content. The wettability of Al alloy on Cu and Ni-palte is better than that on Al₂O₃-plate : this is attributed to the interfacial reaction between the Al aiioy and the metal substrate.

MANET 라우팅 프로토콜 QoS 지원서비스의 성능평가에 관한 연구

鄭燦赫,金鉉郁,李光培,姜景仁,朴京培,劉忠烈,吳世德,裵振勝,趙榮泰 明知大學校 産業技術硏究所 2004 産業技術硏究所論文集 Vol.23 No.-

In this paper, we evaluated two main QoS supporting routing protocol on wireless ad hoc network. At presence, wireless mobile communication focuses on how to efficiently support mobility of users more than QoS guarantee. However, in order to satisfy requirement of various applications which have been or will be served, QoS support service between source and destination becoming a very important issue. Of all routing protocols, DSR and AODV are very important routing protocol in MANET. So we simulated DSR and AODV QoS Routing Protocol Through simulation evaluation tool NS(Network Simulation) based on various environments.

선인장 양심실 보조장치의 설계 및 임상적용을 위한 평가

민병구,박찬영,최재순,이혁수,황창모,김삼성,윤걸중,김종원,선경,이경갑,정종태,김원곤 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.1

현재 개발되고 있는 맥동형 이식형 인공심장은 완전이식형 인공심장과 좌심실보조장치 뿐이다. 좌심실보조장치를 장착한 환자의 10~15%가 우심실의 보조를 필요로하고 완전이식형 인공심장의 장착을 위해서는 자연심장을 제거해야하는 상황에서 이식형 양심실보조장치에 대한 필요성이 대두되고 있다. 본 연구진은 완전이식형 인공심장으로 개발된 한국형 인공심장을 개선하여 양심 실 보조장치를 개발하였다. 양심실보조장치는 이동형 작동기식 미케니즘을 이용하고 있으며 에너지 변환장치와 감속기로 구성된 작동기와 혈액주머니, 그리고 내장형 제어기로 구성되어 있다. 선인장 펌프로 명명된 KAH350은 캐뉼라의 연결을 위한 커넥터를 포함하여 길이 177mm, 폭 164mm, 높이 67 이고 무게 780g이며 최대 심박출량은 5L/min 이다. 양심실보조장치로 개발된 선인장펌프는 좌심실보조장치로도 응용이 가능하다. 이식적합성과 생체적합성을 평가하기 위하여 좌심실보조장치로 5회, 양싱실보조장치로 6회의 동물실험을 수행하였다. 각각 최장 28일간 생존하였으며 11회의 동물실험중 장치의 결함에 의한 것이 3회 있었는데 이들은 모두 전자장치의 결함과 방수처리문제였다. 현재 이식적합성과 일박출량을 향상시킨 KAH400모델이 개발중이다. The types of pulsatile implantable artificial hearts that are on the way of development and have been developed are totally implantable artificial heart and implantable left ventricular assist device (LVAD). Approximately 10% to 15% of all patients Implanted with wearable VADs have required right heart support with another device. And it is reluctant to patient who should remove his or her own heart to be implanted with total artificial heart. These situations drive the development of implantable bi-ventricular assist device (BVAD). The Korean BVAD was develophed by modifying the moving actuator type Korean artificial heart. This electro-mechanical BVAD comprises actuator including energy converter and reduction gear train, blood sacs, and internal motor and energy controllers. The KAH350 which is named as 'Cactus Pump' is 177mm in length, 164mm in width, and 67mm in thickness including connectors and nuts. The weight and maximum cardiac output of Cactus Pump is 780g and 5L/min, respectively. The Cactus Pump that was developed as BVAD could be used as LVAD by attaching compliance caps on the 2 ports of one ventricle. The animal experiments were undergone 5 times for LVAD, and 6 times for BVAD. The best records were 28 days survival in both applications. There were 3 times of device failure and they were all associated with electrical connection and hermetic sealing. The KAH400 that has improved anatomical fitting characterisitcs and stroke volume is on development.

집적화된 실리콘 압력센서의 출력전압 보상파라미터 추출 및 그 특성

이보나,김건년,박효덕,신상모,이경탁,김찬,권혁채,이상조,박현주 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

An integrated silicon pressure sensor has been designed, fabricated and tested. The signal conditioning circuits were designed to include calibration and temperature compensation of output voltage through trimming of diffusion and ion-implanted resistors. Before trimming of resistors, the compensation parameters such as pressure sensitivity, temperature coefficient of pressure sensitivity, temperature coefficient of piezoresistors and pressure sensitivity of piezoresistors were measured. Then offset voltage, span, and temperature coefficients of offset voltage and span were calibrated by trimming of resistors. The measured output voltage met our design specification and simulation value above room temperature. But, the measured output voltage at -30°C deviated from our design specification and simulation value because the offset voltages were found to vary randomly as a function of temperature.

뇌자도 측정을 위한 저잡음 Nb SQUID 센서의 설계 및 제작

이용호,권혁찬,김진목,이상길,임청무,박용기,박종철 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

We report on the design, fabrication and performances of a low-noise Nb SQUID sensor for neuromagnetic measurements. The main features of the developed sensor are i) large flux-to-voltage transfer, making the SQUID readout electronics simple, and ii) use of the integrated planar pickup coil to eliminate the environmental magnetic field noises. The magnetic field noise of the developed SQUID sensor is below 5 fT/√Hz at 100 Hz, which is low enough to be used in neuromagnetic measurements.

지속성 외래복막투석 환자들의 예후에 영향을 미치는 요인들에 관한 고찰

권혁만,김찬덕,조지형,장민화,최혁준,이현철,박자용,박선희,김용림 대한신장학회 2004 대한신장학회잡지 Vol.23 No.2

무선 애드 혹 기반 액티브네트워크상에서 QoS지원에 관한 연구

李基源,裵振勝,丁燦赫,金玄郁,李光培,姜景仁,朴京培,文泰洙,郭承郁,河載承 明知大學校 産業技術硏究所 2003 産業技術硏究所論文集 Vol.22 No.-

Abstract - In this thesis, we propose a QoS supporting method on wireless ad hoc-based active network for improving reliability. On the loss of route path, the existing DSR routing protocol has several problems with wireless network communication because of decease of data reception rate and increase of network load. The proposed method improves reliability of data transfer by using functions of active network. That is, by using functions of active nodes and active packets, the proposed method supports QoS with reservation transfer method that saves data packets on transfer at intermediate nodes with lost path and then re-transmit the packets after route reconfiguration.

이동 애드 혹 네트워크에서 QoS를 지원하는 AODV 라우팅 프로토콜

吳世德,趙榮泰,丁燦赫,金玄郁,李光培,姜景仁,朴京培,文泰洙,郭承郁,河載承 明知大學校 産業技術硏究所 2003 産業技術硏究所論文集 Vol.22 No.-

Abstract - In this paper, we propose a bidirectional mobile Ad Hoc routing protocol based on AODV(ad-hoc on-demand distance victor routing) with QoS(quality of service) support. At presence, wireless mobile communication focuses on how to efficiently support mobility of users more than QoS guarantee. However, in order to satisfy requirement of various applications which have been or will be served, QoS guarantee between end point is a very important issue. The existing AODV routing protocol is implemented to use only BE (Best Effort) service. However, actual wireless mobile environment requires to reduce a waste of communication resources and meet with the real-time change of data paths by setting up routes with QoS support, considering available communication resources at each node in advance. Therefore, in this thesis, we propose an adaptive QoS support method using hello message in order to rapidly meet with the change of available communication resources and to smoothly perform route maintenance. For performance evaluation, we analyzed the average date reception rate. At that time, we used evaluation parameters such as node's mobility -stop time, hello message period, and packet priority, considering the node's mobility and the number of best effort/QoS data flows. As results, we found that with our proposed method the average data reception rate was increased 16.3% for 0 mobility-stop second case and 4.7% for 300 mobility-stop second case.

동일한 환자에서 조혈모세포이식 전후의 호중구감소 기간 중 감염양상에 대한 비교연구 : 중심정맥관 관련 패혈증을 중심으로 Based on Central Venous Catheter Related Septicemia

류재호,노규태,이영석,이영호,권혁찬,김재석,김효진,이영민,박혜원,박근희 대한조혈모세포이식학회 2002 대한조혈모세포이식학회지 Vol.7 No.1

연구배경: 동일한 환자를 대상으로 조혈모세포이식 전 일반 병실에서의 관해유도 항암제치료 및 강화요법으로 인한 호중구감소 기간의 감염양상과 고용량 항암제치료 후 무균실에서의 조혈모세포이식 시 호중구감소 기간의 감염양상을 중심정맥관 관련 패혈증을 중심으로 비교 연구함으로써 효율적인 감염관리지침을 마련하고자 하였다. 대상 및 방법: 1999년 1월부터 2001년 7월까지 2년 7개월간 동아대학교병원 일반병실에서 악성혈액질환으로 항암제 치료를 받다가 조혈모세포이식을 시행받았던 22명을 대상으로 중심정맥관 관련 패혈증의 형태를 비교분석하였다. 결과: 대상 환자들의 일반병실과 무균실에서의 입원기간은 각각 32±13일, 33±19일, 호중구 감소기간은 15±12일, 17±18일, 호중구 감소기간의 발열 횟수는 14회, 14회로서 입원병실의 종류에 따른 차이는 없었다. 환자들의 중심정맥관 사용일수는 일반병실에서 29일(7~545일), 무균실에서 100.5일(25~606일)이었으며, 총 사용일수는 각각 1,515일, 3,250일로서 무균실에서의 중심정맥관 사용일수가 의미 있게 길었다(P=0.001). 중심정맥관 사용 일수에 대한 감염률은 각각 5.28/1,000일, 3.08/1,000일로서 일반병실에서 그 빈도가 높았으나 통계적 유의성은 보이지 않았다(P=0.141). 결론: 중심정맥관 삽입 후 일반병실에서 항암제 치료를 받던 환자가 조혈모세포이식을 위하여 무균실에 입원하는 경우, 중심정맥관을 교체하는 것이 감염관리를 위하여 바람직할 것으로 생각된다. Background: We compared the incidence of central venous catheter (CVC) related septicemia during neutropenic period in the same patient, which developed following chemotherapy for remission induction and consolidation, or hematopoietic stem cell transplantation (HSCT). Methods: We retrospectively reviewed the medical records and laboratory data of 22 patients with hematologic malignancies who received anticancer chemotherapy followed by HSCT at Dong-A University Hospital between January, 1999 and July, 2001. We investigated the duration of hospitalization, duration of neutropenic period, duration of catheterization, microbiologically documented organisms and incidence of CVC related septicemia. Results: The data in general ward (before HSCT) and laminar air flow room (after HSCT) were as follows: duration of hospitalization was 32±13 days and 33±19 days, duration of neutropenic period was 15±12 days and 17±18 days, median duration of catheterization was 29 days (7~545 days) and 100.5 days (25~606 days) (P=0.001), and incidence of CVC related septicemia was 5.28/1000 days and 3.08/1000 days, respectively. In the CVC related septicemia, the most common etiologic organism was coagulase negative staphylococcus. Conclusion: We suggest that the exchange of CVC before admission to laminar air flow room could decrease the incidence of CVC related septicemia in HSCT recipients.

A second-look endoscopy after endoscopic submucosal dissection for gastric neoplasm does not reduce postoperative bleeding (초)

( Chan Hyuk Park ),( Jun Chul Park ),( Hyuk Lee ),( Sung Kwan Shin ),( Sang Kil Lee ),( Yong Chan Lee ) 대한내과학회 2012 대한내과학회 추계학술대회 Vol.2012 No.1