GMAHN 환경에서의 TCP 프로토콜 성능 분석

吳世德,金玄旭,李光培,張良根,裵振勝,金在浩 明知大學校 産業技術硏究所 2007 産業技術硏究所論文集 Vol.26 No.-

Recently, GMAHN that provides interface between MANET and Wired Network has been focused in Mobile Communication. It is necessary that The technology provide reliable data transmission technology between mobile node and wired network in MANET environment that varing by the node movement. In this paper, using the TCP protocol(Tahoe, Reno, Vegas, SACK)that increases reliability between source and destination, we applied the TCP protocol mechanism to various environment, and compared result, and also proposed the efficient TCP mechanism by comparing each mechanism.

과맥의 育種母材 選拔을 爲한 主要特性에 關한 硏究

吳瀁鎬,李康世 群山大學校自然科學硏究所 1986 自然科學硏究 Vol.1 No.-

有用因子의 保存과 利用度의 提高라는 觀點에서 國內外 180種의 과맥品種에 대하여 特性調査를 실시한 결과 原産地와 穗型에 따라 形質의 變異가 현저하였다. 특히 稈長, 穗長, 芒長, 抽穗度, 穗密度 등의 形質에서 品種群間 差異가 뚜렷하였음에 반하여 小穗段數는 變異가 微微하였으며, 芒長, 穗密度는 雙峰曲線을 가진 變異를 나타내었다. 또한 形質間에 있어서도 原産地와 穗型이 다른 品種群間에 서로 다른 相關關係를 보여 각 形質別로 期待되는 品種의 探索에 많은 知見을 얻었으며 나아가 特徵있는 育種母材의 選拔이 可能하였다. From a viewpoint of both preservation of useful genes and reconsideration of their utilization, the examination into characters of 180 kinds of naked barley varieties within and outside Korea resulted in the conspicuous variation of characters according to source of varieties and ear-types. Especially, the differences between varietal groups in characters of culm length, spike length, awn length, flag leaf-spike distance, spike density, and the like, were distinct, while the variation in number of rachis was insignificant. And awn length and spike density showed a variation with bi-normal distribution curves. Also, the different correlations between varietal groups of different source of varieties and ear-types appeared in even characters, and much knowledge was obtained from the search of varieties expected according to individual characters, and furthermore the selection of characteristic parental sources for breeding was possible.

Java Applet을 이용한 SNMP 망 管理 使用者 인터페이스

오양훈,송왕철,강건호 濟州大學校工科大學産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.2

The internet enables multivendor computer systems to join together so that many different models of network devices can co-exist with one another. These days a management program for a web-based SNMP network device is being developed by using web techniques such as HTML. Java Applet, etc. This paper proposes a user interlace technique for managing a web-based network to provide static, dynamic, and interactive management information. Hence. the implementation of the user interface using the web-based technique of Java Applet, makes it possible for a manager to easily search and manage agent MIBs through a browser.

Ladle 내에서 기포에 따른 액상 영역의 유동학적 특성에 관한 가시적 연구

오율권,서동표,양호동 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

In the present study, the gas injection system based on air-water model was designed to investigate the fluid-dynamics characteristics of liquid zone into a ladle. PIV system and camera techniques were applied to analysis flow patterns at the liquid zone. Gas flow rate is one of most important factors which could feature a flow pattern in a gas injection system. At low gas flow rate, upward bubble flow induced by buoyancy force is predominant and does not make an impact on mixing due to a weak circulation flow. However, with increasing gas flow rate, the kinetic energy of bubble increases and a strong circulation flow develops in the liquid. Such a flow in the liquid develops vortex and improve the mixing process. Due to the centrifugal force, circulation flow was well developed near both wall sides and upper region respectively.

초음파 가진시 물의 비등열전달 과정에서 형성되는 압력장 해석을 위한 수치해석적 연구

양호동,오율권 朝鮮大學校 機械技術硏究所 2005 機械技術硏究 Vol.8 No.2

본 연구에서는 물을 가열하는 동안, 초음파 진동에 의해 형성된 음압이 비등 열전달 과정에 미치는 영향을 알아보기 위해 수치해석적 방법을 이용하여 조사해 보았다. 수치해석은 40㎑의 초음파 진동을 진동판 밑변에 부착된 1개의 초음파 진동자에 가진하는 것으로 하였고, 해석 모델은 진동판 밑면을 유한요소법을 이용하여 모델링한 후, 해석 모델에 경계요소법을 적용하여 음장내의 음압을 해석하는 결합형 유한요소-경계요소법(coupled FE-BEM)을 적용하였다. 또한, 초음파 가진으로 인해 형성되는 음압이 열전달 촉진에 영향을 미치는 중요한 요인의 하나로 작용하고 있기 때문에, 비등 과정에서의 열전달 계수를 초음파 진동을 가진한 경우와 가진하지 않은 경우로 나누어 측정하고 음압과 열전달 촉진과의 관계를 살펴보았으며, 실험결과, 초음파 진동자 부근에서의 열전달 촉진 형성 결과와 음압의 형성 결과가 유사한 형태를 보이는 것을 확인할 수 있었다. The present study was numerically investigated that the acoustic pressure caused by ultrasonic vibration has an effect on boiling heat transfer in the water. For the numerical work, a coupled finite element-boundary element method(FE-BEM) was used to calculate the acoustic pressure in the water. In case of the numerical model, the modeling of vibrating plate installed an ultrasonic transducer was performed by the finite element modeling. And then, finite element modeling data consisted element and node number was converted to the boundary element data by SVS(Structural Vibration Simulator). Also, the local heat transfer coefficient was experimentally measured and was compared with the acoustic pressure distributions in order to investigate the relationship between acoustic pressure and enhancement of heat transfer. The results of this study reveal that the acoustic pressure is some of the facts enhanced heat transfer as the profile of acoustic pressure variation is consistent with that of enhancement of heat transfer.

방사선 측정 및 해석 연구 : 원자로 냉각수중의 방사능해석에 의한 결함핵연료봉의 평가 Assessment of Defected Fuel by Analysis of Reactor Coolant Activities

양재춘,오희필,전재식,이호연,오헌진,정문규,박해용 충남대학교 기초과학연구소 1987 연구논문집 Vol.7 No.-

중성자와 우라늄의 핵반응에 의해 생성된 핵분열생성물의 물리적 특성을 이용하여 원자로 내의 핵연료 상태를 해석하는 모델을 개선하였다. 이 모델에서는 고체 핵연료 내에서 특정핵종의 핵분열생성물의 생성과 이것이 원자로 냉각재까지 방출되는 과정을 계산하고 추적하여 방사능농도와 결함 핵연료봉의 수를 관계짓는 방정식의 계수들을 결정한다. 핵분열생성물의 거동은 이탈(knock out)과 이동(migration) 두 부분으로 나누어 해석하였으며 트램프 우라늄의 영향을 분리할 수 있도록 하였다. 실측자료로는 가압 경수형 원자로인 고리 원자력발전소 1호기의 1차 냉각재를 분석해서 얻은 I-131과 I-133의 방사능 강도를 이용하였다. 이 실험자료와 위 방정식에서 구한 방사능 강도로부터 구한 결함 핵연료의 수는 제3주기에서 9.34±1.13개 제6주기에서 0.294±0.092개로 나타났다. An improved mothod of assessing fuel status by analyzsis of the fission product in the reactor coolant system is proposed. The release mechanism of specific fission products is established for determination of the coefficients in the equations which relate the radioactivities with the amount of detected fuel. Knock-out and migration models are employed in the formulation of the release mechanism. The influence of the tramp uranium is quantified. Sample calculations were made for KNU 1 reactor system using the I-131 and I-133 concentrations in the primary coolant. The estimated number of defected fuel pins in the third and sixth cycles appeared to be 9.34±1.13 and 0.294±0.092, respectively.

보리 이삭의 소수 위치에 따른 망과 립의 특성

오양호,이강세 群山大學校基礎科學硏究所 1995 基礎科學硏究 Vol.10 No.-

쌀보리의 이삭에 관한 기초자료를 얻고자 우리나라에서 육성된 쌀보리의 품종을 공시하여 소수 위치에 따른 망의 길이와 무게, 입중등을 조사한 바 그 결과를 요약하면 다음과 같다. 1.이삭의 정단부로부터 3∼5번째 소수가 망장 및 망중의 평균치와 2∼4번째 소수가 입중의 평균치와 각각 일치하였다. 2.이삭의 기부로부터 3∼4번째 소수의 망이 가장 길고 무거웠으며 5∼6번째 소수의 입중이 가장 무거웠다. 3.측렬 소수는 중앙렬 소수에 비하여 망장은 13∼26%, 망중은 24∼41%, 입중은 18∼25% 적은 값을 보였다. Nami형 품종은 Uzu형 품종에 비하여 중앙렬과 측렬간 망장, 망중 차이가 적었다. 4.망중/망장 비로 볼때 Uzu형 품종은 Nami형 품종보다, 그리고 중앙렬은 측렬보다 망이 더 굵었다. 5.이삭을 3등분 하였을 때 망장, 망중은 하부와 중앙부간 차이가 없었으나 상부보다는 길고 무거웠다. 입중은 상부가 항상 가벼웠고 중앙부는 하부보다 무겁거나 같았다. 6.망중이 무거운 소수일수록 입중이 무거웠다. To obtain basic information for characteristics of naked barley cultivars, awn length and weight, kernel weight along spikelet positions of some cultivars bred in Korea were investigated. 1.Awn length and weight of third to fifth spikelet, and kernel weight of second of fourth spikelet from spike tip were not different from each mean value for tatal of spike. 2.From the spike base, awn of third to fourth spikelet was longest and heaviest, and kernel weight of fifth to sixth spikelet was heaviest. 3.Value for awn length, awn weight, and kernel weight of lateral row florets was lower 13 to 26%, 24 to 41%, and 18 to 25%, respectively than one for those of cental row floret. Difference for awn length and weight between central and lateral row in Nami type cultivars compared to Uzu type cultivars was small. 4.In the ratio of weight/length of awn, awn of Uzu type cultivars was thicker than that of Nami type cultivars, and awn of central row was thicker than those of lateral raws. 5.When one spike was divided into three parts, awn length and weight of low part were not different from those of central part, but were longer and heavier than those of upper part. The order of kernel weight was central≥low>upper part. 6.Kernel weight was linearly related to awn weight.

수치해석을 이용한 음향장내의 압력장 해석에 관한 연구

오율권,양호동,서동표 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

Applying ultrasonic waves in a medium enhance the heat transfer, judging from the facts that applying ultrasonic waves to the liquid medium gives rise to areas of high and low local pressure. Therefore, in the present study, a coupled finite element-boundary element method(FE-BEM) was used to calculate the acoustic pressure in a medium. For the numerical analysis, we performed the process of finite element modeling. This modeling data was converted to the boundary element data by SVS(Structure Vibtation Simulator). SVS programmed was composed of FORTRAN language and based on a coupled FE-BEM. The results of numerical analysis reveal that acoustic pressure is increased by 60% at the ultrasonic intensity of 340W and the higher acoustic pressure distribution near two ultrasonic transducers.

알루미늄 캐스팅 타이어 몰드 주조시 트레드 부에 발생하는 열변형 예측에 관한 연구

양호동,오율권 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.2

In this study, the thermal deformation inside the aluminum casting tire mold was analyzed using the numerical analysis method and was investigated using the experimental method. The metal casting device used for manufacturing the tire mold products for automobiles in the actual industrial field was selected as an analysis model, and AI-Mg system alloy (AC7A) widely used for metal casting was selected as the mold material. For the numerical analysis, "COMSOL Multiphysics", the commercial code based on the finite element analysis (FEA), was used in order to predict the thermal deformation of the AC7 A including temperature, displacement and stress distribution. Also, in order to verify the results calculated by the numerical analysis, the experiment for temperature measurement inside the tire mold was performed using the K-type thermocouple under the same condition of numerical analysis method. In detail, the displacement inside the AC7 A tire mold was closely related to the temperature difference. The displacement for 15 minutes in the metal casting device appeared to be larger at the center parts of tire mold (tread part) than on its sides, and the one calculated for the time until it was completely cooled at atmosphere temperature after it was removed from the metal casting device appeared to be larger on the measurement points of 1, 4 and 7 near the atmosphere than on other points. Moreover, the stress inside the AC7A tire mold appeared to be larger at the center parts of tire mold (tread part) because of the shrinkage caused by the cooling speed difference for the initial 15 minutes, and larger on the measurement points 2, 5 and 8 when the mold was removed from the metal casting device because of slow cooling speed. From these numerical analysis conditions and results, when the temperature distribution calculated by the numerical analysis and the one actually measured by the experiment were compared with each other, it appeared that there was a slight temperature difference between them because of the latent heat of the AC7A during the phase change process but th6eir cooling patterns were almost similar results.

The Study on Medicinal Flora of Several Uninhabited Islands in Jindo-gun, Chonnam province

Yang,Hyo-Sik,Kim,Jong-Wook,Oh,Man-Ho 한국자원식물학회 2003 Plant Resources Vol.6 No.1

The medicinal plants in 22 unhabited islands of Jindo-gun, Chonnam provincde were investigated from March 2000 to October 2002. The medicinal plants in 22 uninhabited islands of Jindo-gun were consisted 366 taxa; 95 families, 269 genus, 309 species, 52 varieties, 3 forma, and 2 subspecies. Important medicinal plants on survey area were Lemmaphyllum microphyllum, Dendropanax morbifera, Ficus erecta, Farfugium japonicum, Machilus thunbergii, Juniperus chinensis var. procumbens, Dendrobium moniliforme, Pyrrhosia tricuspis, Cinnamomum japonicum, Pittosporum tobira, Kadsura japonica, and Daphniphyllum macropodum, This result can be used as basic information data for medicinal research and the conservation of uninhabited islands.