이동 애드 혹 네트워크에서의 환경적응형 QoS AODV 라우팅 프로토콜에 관한 연구

裵振勝,宋東勳,吳世德,鄭燦赫,金玄郁,李光培,文泰洙,郭承郁,河載承 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 propose a bidirectional mobile Ad Hoc routing protocol based on AODV(ad-hoc on-demand distance vector 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 points 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 data 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 16.293%, 15.914%, 17.238% for 300 mobility-stop second case and 4.809%, 4.264%, 2.956% for 300 mobility-stop second case.

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.

비행시험 기법 : 스핀 SPIN

나승혁,이주하 한국항공운항학회 1994 한국항공운항학회지 Vol.2 No.-

본 연구 논문은 항공기 개발에 있어서 비행시험의 최종 단계라 할 수 있는 스핀시험의 정의, 스핀 시험방법 및 스핀 진입시의 회복방법과 실제 비행에서의 스핀 특성으로 스핀에 대한 안전성 제고 및 비행시험의 중요성을 논하였다.

Wire Saw 슬러리로부터 Si와 SiC의 선택적 회수

한승열,이종대,전진혁,박노국,이태진,류시옥 嶺南大學校 工業技術硏究所 2004 工業技術硏究所論文集 Vol.32 No.1

This study was focused on the recovery of Si and SiC from wire saw slurry in wire saw slicing process. In order to separate Si and SiC from wire saw slurry, alkali dissolution method was used and then Na₂O showed superior dissolution property of Si. At this time, SiC was separated as powder from alkali aqueous solution. Si was dissolved as a liquid in alkali aqueous solution. After removing SiC powder, the powder was obtained by drying alkali aqueous solution and then it's XRD analysis showed that it was the water glass (Na₂SiO₃).

외부 프리스트레스 도입에 의한 노후된 콘크리트 거더교의 보강성능평가

박승범,홍석주,이봉춘,장석호,권혁준 충남대학교 산업기술연구소 2000 산업기술연구논문집 Vol.15 No.1

One of the promising methods to enhance the flexural strength of a externally prestressed girder is to place the tendons with large eccentricities. The analysis and design of composite girders prestressed by external tendons involve difficulties related mainly to the position of anchorages and the construction sequences. This study was conducted on the concrete bridges reinforced by the continuous girders and the external prestressing. The test results in this study showed that the external prestressing of a composite girder increased the range of the elastic behavior, reduced deflections, increased ultimate strength, and added to the redundancy by providing the multiple stress paths.

정보통신산업에서의 기술혁신 유인과 시장구조 진화

신혁승,윤충한,한경동 한국국민경제학회 2003 경제연구 Vol.21 No.1

기술혁신 및 시장구조의 진화과정에서 효율적 기업이 계속하여 신기술을 독점하는 지배적 구조의 지속 현상(increasing dominance)과 각 기업의 기술적 우위와 계속하여 교차하는 현상(action-reaction)이 어떠한 상황에서 발생하게 되는지를 기업의 기대 종류, 기업의 초기비용 구조 등을 통해 살펴보고, 특히 정보통신산업에서 나타나는 네트워크 외부성의 존재가 기업의 기술혁신 유인과 시장구조의 진화 패턴에 미치는 영향을 고찰하고 있다. We examine the evolution of market structure by technological innovation. There are two kinds of phenomena in the evolution. One is the 'increasing dominance' where the efficient firm continues to be a leading firm. The other is the 'action-reaction' where technological superiority of firms changes over time. We derive the conditions under which these two phenomena occur. Also, we look at the effect of network externality on the pattern of the innovation incentive and market evolution.

短粒種벼의 吸濕平衡含水率

琴東赫,鄭春植,朴勝濟 成均館大學校 科學技術硏究所 1987 論文集 Vol.38 No.1

Adsorption equilibrium moisture content for short grain rough rice of Akihikari variety were determined at 20, 30, 40 and 50℃ and relative humidities ;ranging from 46.3 to 90.9 percent. A static method of equilibrium was used by suspending 16g of samples in jars with different saturated salt solutions. Triplicated samples were used for all trials. A new quadratic equation was proposed to correlate the EMC data and compared with Henderson, Chung-Pfost, and Day-Nelson equations. The goodness of fit of each equation was evaluated by determining the "Error Mean Square(EMS)". Quadratic equation gave the smallest EMS value followed by the Henderson equation.

실제좌표 공간에서 선형 진동시스템의 해석기법

백승호,황재혁,박명호,이재홍 한국 항공대학교 항공산업기술연구소 1996 航空宇宙産業技術硏究所 硏究誌 Vol.6 No.-

The coefficients of a linear nonconservative system are arbitrary matrices lacking the usual properties of symmetry and definiteness. A method is developed herein for the efficient analysis of linear nonconservative systems. This constructive method utilizes equivalence transformations, and does not require conversion of the equations of motion to first-order forms.

클로르헥시딘 바니쉬의 적용이 교정용 브라켓의 전단접착강도에 미치는 영향

임동혁,김태우,장영일,남동석,양원식,백승학 대한치과교정학회 2000 대한치과교정학회지 Vol.30 No.2

본 연구의 목적은 클로르헥시딘 처리가 교정용 브라켓의 전단접착강도와 탈락 양상에 미치는 영향을 비교하는 것이다. 실험군으로 4주간 4회의 클로르헥시딘 바니쉬를 도포한 22개의 사람 소구치를 선택하였고, 대조군으로 아무 처리도 하지 않은 22개의 사람 소구치를 선택하였다. 모든 치아는 37%의 phosphoric acid gel로 부식시키고 교정용 브라켓을 같은 조건으로 부착시켰다. 전단접착강도의 측정을 위해 Instron universal testing machine(model 4466)을 이용하였고, 법랑질과 브라켓 표면은 SEM으로 관찰하였다. 결과의 분석은 t-test를 이용하였으며 결과는 다음과 같다. 1.클로르헥시딘의 법랑질 처리는 전단접착강도에 영향을 미치지 않았다. 2.클로르헥시딘으로 법랑질을 처리한 경우와 그렇지 않는 경우에 브라켓 탈락 양상에 차이가 없었다. 따라서, 클로르헥시딘으로 법랑질을 처리하여도 브라켓 접착에 유해한 작용이 없었고, 따라서 임상사용에 적합하다고 생각된다. The purpose of this study was to determine whether the application of chlorhexidine varnish affects the shear bond strength and failure pattern of orthodontic brackets or not. The experimental group consisted of 22 human premolars which extracted after chlorhexidine vanish application(4 times for 1 week interval) in vivo, and the control group consisted of 22 human premolars which extracted without any pre-treatment. After all teeth were etched with 37% phosphoric acid gel, metal orthodontic brackets (Q-3002, RMO, USA) were bonded to each tooth using auto-polymerizing orthodontic resin (Ortho-One, Bisco, USA) with the same bonding procedure. The shear bond strength was measured with Instron universal testing machine (model 4466, Instron Ltd., England), and the failure pattern of each bracket was examined with Scanning Electron Microscope (SM 840A, JEOL, Japan). The data were analysed statistically with t-test. The results were as follows : 1.Application of chlorhexidine varnish had no significant effect on the shear bond strength of the orthodontic bracket. 2.There was no significant difference in the failure pattern of orthodontic bracket between the experimental group and the control group.

다가야스병에 의한 돌연사 부검 1예

이재혁,조승제,박종태 大韓法醫學會 1994 대한법의학회지 Vol.18 No.1

A 22-year old male patient was admitted to the Emergency room of local clinic because of the stuporous mental status. On physical examination, he appeared as a chronically ill, slender man. There was complete absence of the left arm pulse, and a prominent thrill and briuts were present over the right subclavicular area. The blood pressure which checked in the other regions except for the left arm was hypertensive(right arm 180/100, right leg 210/120, and left leg 200/130mmHg). An x-ray film of the chest and doppler ultrasounds showed characteristic dilatation of aortic arch, ascending aorta and innominate artery. The clinical impression was Takayasu's disease. This patients's condition deteriorated rapidly in spite of intensive care and died on the seventh hospital day. At autopsy, the cause of death was massive left brain infarction due to middle cerebral artery embolization. The opened luminal surface of the aorta and its major branches revealed irregulary thick-walled, tree-bark-like appearance. Also in the left common carotid artery, the lumen was nearly obliterated by thromi and intimal fibrous plaques. But the thoraco-abdominal aorta was spared. Microscopic examination disclosed granulomatous and sclerosing arteritis. In the former, the inflammatory process was confined to the media and adventitia and the cell infiltrate consisted predominantly of lymphocytes, plasma cells and histiocytes, with a varying number of giant cells. The latter was characterized bland intimal fibrous hyperplasia, medial degeneration with disrupted elastic lamella, and adventitial fibrosis. The pathologic diagnosis was Takayasu's disease of type I.