• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.672-676
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• 2018

Objective: An experiment was conducted to study the effect of a blend of essential oils (BEO) on enteric methane emission and growth performance of buffaloes (Bubalus bubalis). Methods: Twenty one growing male buffaloes (average body weight of $279{\pm}9.3kg$) were divided in to three groups. The animals of all the three groups were fed on a ration consisting of wheat straw and concentrate mixture targeting 500 g daily live weight gain. The three dietary groups were; Group 1, control without additive; Group 2 and 3, supplemented with BEO at 0.15 and 0.30 mL/kg of dry matter intake (DMI), respectively. Results: During six months feeding trial, the intake and digestibility of dry matter and nutrients (organic matter, crude protein, ether extract, neutral detergent fibre, and acid detergent fibre) were similar in all the groups. The average body weight gain was tended to improve (p = 0.084) in Group 2 and Group 3 as compared to control animals. Feeding of BEO did not affect feed conversion efficiency of the animals. The calves of all the three groups were in positive nitrogen balance with no difference in nitrogen metabolism. During respiration chamber studies the methane production (L/kg DMI and L/kg digestible dry matter intake was significantly (p<0.001) lower in Group 2 and Group 3 as compared to control animals. Conclusion: The results indicated that the BEO tested in the present study have shown potential to reduce enteric methane production without compromising the nutrient utilization and animal performance and could be further explored for its use as feed additive to mitigate enteric methane production in livestock.

• International Journal of Control, Automation, and Systems
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• 제6권3호
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• pp.295-295
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• 2008

• 전자통신동향분석
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• 제8권3호
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• pp.39-52
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• 1993

This study involves a Common Cause Failure (CCF) problem on the ultra-high reliability required system development such as war game operations, nuclear power control, air traffic control, space shuttle missions, and large scale network communication system. The system situation problems are defined according to CCF, reliability and system fault identifications for the development cast verifications in the multi-version redundant software system. Then, CCF analysis of redundant system, system principles and statistical dependence are also described. This validation oh the CCF in the human software interaction system will notify software engineers to conceive what really is CCF contribution factor, not only the internal but the external ones.

• 대한기계학회논문집
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• 제19권3호
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• pp.724-730
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• 1995

Fixed-gain and variable-gain PID control of tension in the winding section of a simple web transport system were evaluated. An open-loop mathematical model for the web transport system was derived and used for the design of the PID controllers. The winding roll radius is a timevarying parameter in the model. The fixed-gain PID controller designed at a particular instant of time could not meet the desired specifications, whereas the variable-gain PID controller could produce accurate tension control in the winding section. An advantage of the variable-gain control is its simplicity. This approach is easy to implement and shows promise for applications where the time-varying parameters are easily measured.

• 대한산업공학회지
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• 제20권2호
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• pp.77-90
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• 1994

Curve-net interpolation surface is one of the most popular method in engineering design. Therefore it is supported with many commercial CAD/CAM system. However, construction algorithm of curve-net interpolation surfaces is rarely opened to the public because of its copy-right. In this paper we establish a construction algorithm of curve-net interpolation surface so called sweeping surface which especially concentrates on trajectory of cross-section curve. We also show the method which can construct sweeping surfaces as NURB or Bezier mathematical models. Surfaces having the form of standard mathematical models are very useful for the application of joining, trimming, blending etc. The proposed surface interpolation scheme consists of four steps; (1) preparation of guide curves and section curves, (2) remeshing guide curves and section curves, (3) blending section curves after deformation, and (4) determination of control points for sweeping surface using gordon method. The proposed method guarantee $G^1$-continuety, and construct the surface salifying given section curves and trajectory of section curves.

• 지구물리와물리탐사
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• 제5권2호
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• pp.93-98
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• 2002

"이산적으로 정의된 수평단면으로부터 광체의 3차원 형태를 생성하는 3D Modeler"시스템을 사용하여 국내의 한 광산에서 개발중인 실제 광체의 모델링을 수행하였다. 이 프로그램을 사용하면 다양한 공간정보를 쉽게 종합하여 모델링을 할 수 있다. 모델링의 결과는 인접한 단면사이를 연결하는 제어점들의 설정에 크게 좌우된다. 제어점의 설정은 단면간의 기하학적 유사성과 광체의 지질학적인 특성 등을 고려하여 작성한다. 작성된 모델은 광체를 3차원적으로 도시하거나 또는 임의의 단면을 추출하여 검토할 수 있으며 이 단면을 수정하여 다시 모델링함으로써 점진적으로 사용자가 원하는 형태의 모델을 구축할 수 있다.

• 전력전자학회논문지
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• 제23권1호
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• pp.47-58
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• 2018

A solar array simulator (SAS) consists of an engine that generates a setpoint according to panel characteristics, a power stage that provides the actual output, and a controller. Particularly, if the control method is not suitable due to the nonlinearity of the solar panel output curve depending on the irradiation amount and the temperature, and the variation of the curve factor depending on the various panel materials, then the panel simulation function cannot be performed properly. Current and voltage mode controls are usually used for the conventional control method. However, these control methods deteriorate the control performance near the maximum power point; thus, a hybrid control method using two or more controllers has been investigated. In this study, we analyze the hybrid control method using three controllers divided into different areas. The design equation of the controller is derived based on the small signal modeling of each controller, and the simulation performance of the solar array simulator verifies its stability and response speed.

• 대한간호학회지
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• 제21권1호
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• pp.41-49
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• 1991

From of old, labor has been accompanied by pain and much effort has been mode to eliminate or diminish the amounts of pain during labor. Little concern has yet been given to the subjective meaning of pain in labor. Recently, rates of cesarean section in Korea and in some other nations have increased rapidly and some investigators are reporting negative reactions such as anger, disappointment and feeling of loss due to lack of control over labor and its pain. These findings are thought to suggest that control of labor and its pain gives some meaning to the laboring woman. Thus the investigators sought to discover the meaning of pain during labor for Korean women. Specific objectives of this study were to explore the meaning of pain in labor to the mothers, their reactions to the experience of labor add their preference for delivery method. The subjects of this study were 95 mothers who delivered their babies in hospital from September 989 to May 1990 : 45 gave birth by vaginal delivery, and 50 by cesarean section. Data were gathered through direct interviews by the investigators, and questions were focused on five areas i.e. mothers' feelings about delivery and their babies, their feelings about of having more children, the most difficult aspect about this labor and delivery, and what they thought the differences were between vaginal delivery and cesarean section. After interview, mothers' answers were summarized, and classified according to the degree of positive or negative attitude. To ascertain the difference in meaning of labor pains and reaction to delivery experience between mothers delivered vaginally and by cesarean section a Median test was done using an SAS. Results were as follows. 1. More mothers who had delivered vaginally realized that they “have became a mother” than those who had a cesarean section(X$^2$＝8.409, df＝3, p＝0.038). 2. Immediate reaction to their delivery experience was more positive for mothers who had a cesarean section. 3. These Korean mothers expressed preference for vaginal delivery. Suggestions for further research on the meaning for mothers of their experience of labor, and on the meaning of pain for mothers who have a cesarean section were made.

• Journal of Magnetics
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• 제16권3호
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• pp.234-239
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• 2011

Transcranial magnetic stimulation utilizes the method of controlling applied time and changing pulse by output pulse through power density control for diagnosis purposes. Transcranial magnetic stimulation can also be used in cases where diagnosis and treatment are difficult since output pulse shape can be changed. As intensity, pulse range, and pulse shape of the stimulation pulse must be changed according to lesion, the existing sine wave-shaped stimulation treatment pulse poses limitations in achieving various treatments and diagnosis. This study actualized a new method of transcranial magnetic stimulation that applies a 3 Stage 2 Switch( power semiconductor 2EA) for controlling pulse repetition rate by achieving numerous switching control of stimulation coil. Intensity, pulse range, and pulse shape of output can be freely changed to transform various treatment pulses in order to overcome limitations in stimulation treatment presented by the previous sine wave pulse shape. The method of freely changing pulse range by using 3 Stage 2 Switch discharge method is proposed. Pulse shape, composed of various pulse ranges, was created by grafting PFN (Pulsed Forming Network) through AVR AT80S8535 one-chip microprocessor technology, and application in transcranial magnetic stimulation was achieved to study the output characteristics of stimulation treatment pulse according to delaying time of the trigger signal applied in section switch.

• 한국공간구조학회논문집
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• 제11권2호
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• pp.139-149
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• 2011

케이블 구조물은 비교적 가볍고 넓은 공간의 형성이 쉬우나 유연한 특징으로 인해 형상의 제어가 매우 민감하다. 이런 구조물은 여러 이유에서 형상의 보정이 필요하며, 특히 부재 제어량과 어떠한 부재를 제어해야 하는가는 것은 많은 연구자들이 고심하고 있는 문제이다. 따라서 본 논문의 목적은 하중법(Force Method)를 이용해서 형상조절을 위한 변위 제어기법을 연구하는 것이다. 논문은 2장에서는 제어 방정식을 설명하고, 3장에서는 단순 케이블 넷 모델을 이용하여 동시 및 순차제어를 고려해 해석을 수행하고 결과를 고찰한다. 4장에서는 보다 더 복잡한 케이블 돔 구조물에 적용하여 가장 유용한 부재에 대해서 논의 하고, 5장에서 결과를 요약한다.