• The Science & Technology
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• no.5 s.444
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• pp.25-27
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• 2006

요즘 들어 황사가 부쩍 심해졌다. 따끔거리는 눈과 마른기침은 물론 목구멍의 고통 못지않게, 건강에 대한 서민들의 걱정도 늘어가고 있다. 해마다 봄철이면 어김없이 한반도를 휩쓰는 이 '황사 재해'의 원인과 대응책을 알아본다.

• KOREAN POULTRY JOURNAL
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• v.25 no.5 s.283
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• pp.166-170
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• 1993

산란개시전후부터 40주령전후까지의 기간은 질병이 가장 발생하기 쉬운 시기입니다. 또한 이시기에 질병이 발생했다면 잘 낫지도 않아 치료기간이 늘어나고 치료비용, 도태, 폐사 등의 증가로 많은 손실이 일어나게 되는데 이러한 원인은 어디에서 일어날까요? 우선 올 여름철에 발생이 우려되는 류코사이토준병에 대해 간단히 살펴보고 이어갈까 한다.

• KOREAN POULTRY JOURNAL
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• v.25 no.4 s.282
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• pp.132-135
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• 1993

산란개시전후부터 40주령전후까지의 기간은 질병이 가장 발생하기 쉬운 시기입니다. 또한 이시기에 질병이 발생했다면 잘 낫지도 않아 치료기간이 늘어나고 치료비용, 도태, 폐사 등의 증가로 많은 손실이 일어나게 되는데 이러한 원인은 어디에서 일어날까요?

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.3
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• pp.243-254
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• 2014

It is essential to predict the coil temperature under over load and over speed conditions for reliability in high speed low torque surface mounted PM synchronous motors(SPM). In the present study, the losses and coil temperature are measured under rated condition and calculated under over speed and over load conditions in the three different motors with 35PN440, 25PN250 and 15HTH1000. The heat transfer modeling has been performed based on acquired losses and temperature. The difference of coil temperature between heat transfer modeling and experiment is less than 6.4% under no load, over speed and over load conditions. Subsequently, the coil temperature of the motor with 15HTH1000 is 84.4% of the coil temperature of the motor with 35PN440 when speed is 0.9 and load is 3.0. The output of motor with 15HTH1000 is 85.2% greater than the output of the motor with 35PN440 when the dimensionless coil temperature is 1.0.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3138-3148
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• 2011

This present study is designed to analyze the mortality and potential years of life lost (PYLL) by malignant neoplasm of lung between OECD countries and Korea before and after the year 2000. We used the methods of Wilcoxon Singed Ranks Test between korean and other 30 OECD countries between 1993-1999 and 2000-2006 year using 2009 OECD Health data(2010) of 30 contries. At the results, the mortality of lung cancer in male korean was significantly increased after 2000 year whereas those in other 23 countries decreased. The mortalities in female were increased in 20 countries including Korea. PYLL in male and female korean were significantly decreased and male PYLL in other 26 countries was decreased, but female PYLL in other countries showed various patterns; increase in 12 countries and decrease in 3 countries. Therefore, the present study elucidated that the lung cancer-induced PYLL in the comparison between korean and OECD countries can be more important parameter.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.2 s.302
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• pp.1-10
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• 2005

The current implementation of TCP for the Internet is not efficient when used for Mobile Ad hoc Networks (MANENTs). This is because TCP assumes that all packet losses are caused by congestion, whereas transmission errors are a main reason for packet losses in wireless networks. To remedy this situation and increase performance, we propose an end-to-end method of using propagation delays and the differences between propagation delays to distinguish the causes for packet losses. The proposed method has two characteristics: Firstly, it is energy-efficient because this solution is only initiated when a packet loss is detected. Secondly, our approach considers only the one way propagation delay and is more accurate in determining causes for packet losses than existing methods which consider round trip time. Petri net models of the proposed TCP and of the standard TCP have been built and simulations have been performed on them. Our simulation results show that the proposed approach increases throughput and reduces propagation delay compared with standard TCP.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.305-314
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• 1996

In the paper, we divide the ATM cells generated by multimedia systems that want to transmit multimedia informations over B-ISDN into two categories:i)a media cell with a media information and ii) a synchronization cell with a synchronization information. We induce a media cell loss equation and a synchroni- zation cell loss equation based on probability distribution functions with on-off source as an input traffic model. In order to meet the requirements of real-time and integrity of multimedia informations, multimedia synchronization cells should provide the delay-sensitive and the loss-sensitive requirements. A traffic control mechanism needs to satisfy above requirements. According to the performance evaluation by a traffic control model simulation, we describe both spatial priority for minimizing the synchronization cell loss and temporal priority for reducing the synchronization cell delay must be applied simultaneously.

• Communications for Statistical Applications and Methods
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• v.16 no.5
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• pp.803-812
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• 2009

The application of extreme value theory to financial data is a fairly recent innovation. The classical annual maximum method is to fit the generalized extreme value distribution to the annual maxima of a data series. An alterative modern method, the so-called threshold method, is to fit the generalized Pareto distribution to the excesses over a high threshold from the data series. A more substantial variant is to take the point-process viewpoint of high-level exceedances. That is, the exceedance times and excess values of a high threshold are viewed as a two-dimensional point process whose limiting form is a non-homogeneous Poisson process. In this paper, we apply the two-dimensional non-homogeneous Poisson process model to daily losses, daily negative log-returns, in the data series of KBW/USD exchange rate, collected from January 4th, 1982 until December 31 st, 2008. The main question is how to estimate extreme quantiles of losses such as the 10-year or 50-year return level.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.493-500
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• 2014

Nonlinear characteristics of cellular counterflow diffusion flame near the radiative extinction limit at large Damk$\ddot{o}$hler number are numerically investigated. Lewis number is assumed to be 0.5 and flame evolution is calculated by imposing an infinitesimal disturbance to a one-dimensional(1-D) steady state flame. The early stage of nonlinear development is very similar to that predicted in a linear stability analysis. The disturbance with the wavenumber of the fastest growing mode emerges and grows gradually. Eventual, an alternating pattern of reacting and quenching stripes is developed. The cellular flame temperature is higher than that of 1-D flame because of the gain of the total enthalpy. As the Damk$\ddot{o}$hler number is further increased, the shape of the cell becomes circular to increase the surface area per unit reacting volume. The cellular flames do not extinguish but survive even above the 1-D steady state extinction condition.

• The Korean Journal of Applied Statistics
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• v.26 no.3
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• pp.471-481
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• 2013

The current VaR Model based on J. P. Morgan's RiskMetrics has problem that actual loss exceeds VaR under unstable economic conditions because the current VaR Model can't re ect future economic conditions. In general, any corporation's stock price is determined by the rm's idiosyncratic factor as well as the common systematic factor that in uences all stocks in the portfolio. In this study, we propose an One-factor VaR Model for stock portfolio which is decomposed into the common systematic factor and the rm's idiosyncratic factor. We expect that the actual loss will not exceed VaR when the One-factor Model is implemented because the common systematic factor considering the future economic conditions is estimated. Also, we can allocate the stock portfolio to minimize the loss.