• Journal of Power System Engineering
• /
• v.4 no.4
• /
• pp.70-77
• /
• 2000

On the dynamic behavior of a simple beam the influences of the velocities and distance of two moving masses have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving masses represented by the time functions. As increasing the velocties of two moving masses on the simple beam, the amplitude of the transverse vibration of the simple beam is decreased and the frequency of the transverse vibration of the simple beam is increased. As the distance between two moving masses increase, the transverse displacement of the simple beam is decrease. The simple beam is very stable in second mode at $\bar{a}=0.5$ and in third mode at $\bar{a}=0.3$.

• Journal of Power System Engineering
• /
• v.4 no.1
• /
• pp.20-25
• /
• 2000

In this study, methods for the characteristics measurement of pneumatic elements using isothermal chamber, the methods for the flow rate and dynamic characteristic measurement of pneumatic control valve, are proposed. An isothermal chamber is a chamber in which the steel wool is stuffed and isothermal condition can almost be realized. Therefore, the instantaneous flow rate could be measured only from the pressure response using the state equation of gas. Effectiveness and simplicity of the proposed method are confirmed by comparing the measured results obtained by proposed methods with the methods defined JIS and the ISO standards.

• 연구논문집
• /
• s.30
• /
• pp.169-176
• /
• 2000

The Evolution of Workflow Managment consists of rhe automation of business procedures or "workflows" during which documents, information or tasks are passed from one participant to another in a way that is governed by rules or procedures. Workflow technologies have evolved from image management system, document management system, relational or object database systems, and electronic mail system. Workflow Management system has the benefits to improve better efficiency, process control,flexibility, business process. Automation of many business processes results in the elimination standdardizing working methods. Consistency in the processes leads to greater predictability in levels of response to customers and software control over processes enables their re-design in line with changing business needs, In this present study, we implement Electronic Approval System which is a kind of Workflow Management system using static and dynamic flow control information on the web environment.

• Journal of Veterinary Clinics
• /
• v.17 no.2
• /
• pp.505-509
• /
• 2000

A five-month old female dog was presented to Teaching Anilmal Hospital, Gyeongasng National University for femur fracture. Previously the dog had been presented to a local hospital. Orthopedic and blood examinations were conducted. There was absent response of conscious propri- oception. The dog stood knuckled onto the digits and had hock dropped, but showed no117a1 values in WBC.RBC, Hb, PCV, BUN, Creatine, Glucose, Cholesterol, AST and ALT. Plain radioaraphs were taken and there were abundant periosteal reaction and malalignment of fragments. The dog was anesthetized and prepared for aseptic surgery. Joshi external fixator and half pins were applied(uni lateral). AT 8 weeks after surgery, the pins were removed from the bone. The fracture was well healed wish no evidence of original fracture line. but mild muscle atropy and shortening of femur were found.

• Journal of the KSME
• /
• v.27 no.3
• /
• pp.180-186
• /
• 1987

초전도 교류발전기는 성능 및 경제성으로 볼 때 종래의 발전기 보다 우수하며 대단위 용량기의 가능성도 커서 세계의 선진각국에서 연구개발을 계속하고 있으며 2000년대에는 1000MVA급 초 전도 발전기의 실용화가 확실시되고 있다. 특히 근래에 교류 초전도체의 개발로 전기 자권선 까지 초전도화가 가능(13)하게 되고 이것을 계자회로에 이용하면 속응여자(fast response excitation)방식 초전도 발전기도 가능하게 된다. 또한 고온 초전도 재료의 개발은 초전도 발전 기의 냉각문제를 더욱 용이하게 할 수 있으므로 초전도 발전기의 실용화는 더욱 앞당겨지리라 생각된다. 초전도 발전기의 개발기술은 정밀가공, 초고진공, 극저온, 초고자력 등 기반기술과 초전도 등 미래기술의 복합체이다. 국내에서는 아직도 이에 대한 연구가 산발적으로 이루어지고 있는 실정인데 앞으로는 국가주도형으로 정하여 장기적이고 조직적인 연구개발이 이루어져야 하겠다.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.78-81
• /
• 2008

현재 전력사업 분야에서는 산업화의 발전과 더불어 전력수요의 갑작스러운 증가와 전 세계적인 지구 온난화 문제를 해결하기 위해서 환경 친화적인 분산전원에 대한 연구가 활발히 진행되고 있다. 본 논문은 분산전원 시스템의 안정성 및 고효율 운전을 위해 계통과 분산전원 상호간의 영향에 대한 연구를 하였다. 계통과 분산전원의 연계시 계통전원의 악영향에 대한 PV 시스템의 응답특성을 과전압 및 부족전압, 순간정전, 전압 써지 등으로 구분하여 각각에 대한 응답특성을 확인하고, 분산전원의 이상 출력이 계통에 미치는 영향을 IEEE 929-2000의 규정을 바탕으로 시뮬레이션 환경을 만들고 각각의 경우에 대한 응답특성을 주파수 허용 변동범위(59.3Hz~60.5Hz)로 확장하여 계통과 PV시스템 상호간의 영향 및 응답특성을 확인 할 수 있었다.

• The Journal of Korean Medicine
• /
• v.21 no.2
• /
• pp.37-42
• /
• 2000

Objectives and Methods : Unlike respiratory anaphylaxis responses, mediators responsible for cardiovascular responses are not clearly elucidated. Main characteristics of cardiovascular anaphylaxis include hypotension and cardiac failure (anhythmia and cardiac contraction failure). In this experiment, the fractionations of Sophorae Radix (SR) were tested for its preventive effects against cardiovascular anaphylaxis in pithed rats. Results : Of the SR fractionations, water fractions, at the concentration of 20 and 60mg/kg, was significantly effective on all the cardiovascular changes in pithed rats. Also, of the cardiovascular changes, depressor response was significantly attenuated by the ethyl acetate (EA) fraction, at the concentration of 60mg/kg. Conclusions : These results suggest that water and EA fractions of the SR fractionations possess anti. anaphylactic effects in pithed rats. Additional research is needed to identify active principles for the observed pharmacological effects.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10c
• /
• pp.425-427
• /
• 2000

접속이 빈번한 웹사이트들의 서버는 동시에 수백개의 커넥션을 처리해야 하므로 효율적인 커넥션 스케줄링 기법이 요구된다. 기존의 SRPT(Shortest Remaining Processing Time first)를 이용한 커넥션 스케줄링 기법은 가장 짧은 처리시간이 남아있는 커넥션을 먼저 처리함으로써 각 문서에 대한 응답시간의 향상을 가져왔다. 그러나, 클라이언트의 요청에 의해 형성된 하나의 커넥션으로 다수의 정적 문서들을 동시에 요청할 수 있는 HTTP/1.1에서 크기가 다른 다수의 정적 문서들이 요청됐을 때, 각 문서에 대한 응답시간은 빠를 수 있으나 커넥션에 대한 전체 응답시간의 향상은 보장할 수 없다. 따라서 본 논문은 HTTP/1.1 환경에서 웹 서버의 CPU와 메모리의 부하가 높을 때 발생되는 성능저하의 단점을 보완하면서 정적 문서 요청에 관한 응답시간을 향상시키는 pipelining 기반의 커넥션 스케줄링 기법을 제시한다. 실험을 통해서 제안한 커넥션 스케줄링 기법이 전체적으로 커넥션에 대한 빠른 응답시간을 보이고, 스케줄링 윈도우의 사용으로 스케줄링에 공평성을 보임을 알 수 있다.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.6 no.2
• /
• pp.203-210
• /
• 2002

In these days, High-strength steel prevails throughout the construction fields for the benefit of structural and economical aspects. But high-strength steel is used by the simple calculation of flexural capacities for the purpose of reducing flexural reinforcement. So, this paper is mainly focused on the shear behavior of high-strength steel reinforced concrete beams without stirrups comparing with normal-strength steel reinforced concrete beams. Specimens were made and tested with the experimental parameters, such as steel yield strength, reinforcement ratios and minimum shear reinforcement. The main result was that not only area but also the yield strength of flexural reinforcement should be considered to predict the shear capacities of concrete beams. In addition, the experimental results were simulated by modified compression field theory analysis program, RESPONSE 2000. A good agreement was achieved between the test results and program analyses.

• Archives of Pharmacal Research
• /
• v.23 no.5
• /
• pp.531-534
• /
• 2000

Nitric oxide (NO), products of activated macrophages, have a great impact on the regulation of cytokine production. The role of NO in non-specific host cells is commonly accepted. On the contrary, its role as an immuno-regulatory molecule is still controversial. In this study, we have investigated the effect of NO on the production of cytokines from murine splenocytes and macrophages. S-nitroso-L-glutathione inhibited the release of both interferone-$\gamma$ and interleukin-2 produced by Th1 cells and tumor necrosis factor-$\alpha$ and interleukin-1$\beta$ produced by macrophages, but did not affect the release of interleukin-4 and interleukin-10 produced by Th2 cells. These results suggest that NO exerts a down-regulatory effect on the secretion of cytokines from Th1 cells and macrophages which are implicated in immune response. Thus, NO may have an important role as an immune-modulatory as well as effector molecule in the immune system.