• 농업과학연구
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• 제39권1호
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• pp.87-95
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• 2012

Land surface temperature (LST) is an important factor in human health, thermal environment, heat balance, global change studies, and as control for climate change. The objective of this study was to assess the influence of Urban Heat Island (UHI) Effects on the LST and NDVI in Cheongju, Korea. The aim was to evaluate the effect of urban thermal environment for LST comparison of satellite-derived and in situ measured temperature. In this study, LANDSAT TM and KOMPSAT scene were used. The results indicated that the minimum LST is observed over dense forest as about $21{\sim}25^{\circ}C$ and maximum LST is observed over industrial area of about $28{\sim}32^{\circ}C$. The estimated LST showed that industrial area, bare soils and built-up areas exhibit higher surface temperatures, while forest, water bodies, agricultural croplands, and dense vegetations have lower surface temperatures during the summer daytime. Result corroborates the fact that LST over land use/land cover (LULC) types are greatly influenced by the amount of vegetation and water bodies present. The LST of industrial area and urban center is higher than that of suburban area, so it is clearly proved that there are obvious UHIE in Cheongju.

• 공학논문집
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• 제3권1호
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• pp.131-138
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• 1998

본 논문은 기술적인 진보보다는 개념적 변화에 초점을 맞추어 근거리통신망의 진화 방향에 대하여 살펴본다. 현재까지 많이 사용되는 주요한 근거리통신망 기술을 토폴로지, 채널의 타이밍구조, 매체접근제어 항목으로 분류하고 최근 근거리통신망에서 나타난 진전된 기술 및 새로운 개념들을 살핀다. 근거리통신망의 진화에서 가장 영향을 미친 근본적인 요소는 집중형 백본 개념으로 보인다. 종래의 LAN의 개념과는 근본적으로는 다른 ATM 기술이 LAN에 적용되고 있으며, 전통적인 근거리통신망이 ATM과 경쟁하기 위해서는 QOS의 지원이 가능하도록 발전해야 될 것이다.

• 한국수자원학회논문집
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• 제33권6호
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• pp.745-755
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• 2000

현재 우리나라에서 홍수조절 업무에 황용하고 있는 홍수관리시스템은 댐에서 조절이 불가능한 댐하류부 수문현상들을 고려하여 방류계획을 수립할 수 없으며, 예측 강우량에 의한 댐으로의 유출상황을 고려한 예비방류에 관한 지침이 마련되어 있지 않다. 따라서 본 연구에서는 댐의 제약조건 댐 상.하류의 유출상황을 고려하여 홍수기 댐을 운영 할 수 있는 모의기법에 의한 모형을 개발하였다. 개발된 모형(EV ROM이라 명명)은 댐에서 조절이 불가능한 댐하류 지류에 의한 하류 홍수제어 지점의 Cumulative Lateral Flow Hydrograph를 고려하여 방류계획을 수립한다. EV ROM에서는 댐하류 지역의 첨두홍수량 경감을 위하여 홍수제어지점의 수문곡선 상승부에서 예비방류를, 첨두부에서는 댐에 저류를 하였다가 수문곡선 하강부에 다시 방류를 수행하는 특징이 있다. EV ROM을 강우-유출모형에 결합하여 금강수계 대청댐을 중심으로 3개 홍수사상에 적용해 본 결과, 기존의 Rigid ROM이나 Technical ROM 보다 우수한 것으로 나타났다. 이는 본 연구에서 개발한 EV ROM이 댐 유역뿐만 아니라 댐하류 홍수제어지점의 수문상황을 동시에 고려하여 댐의 방류계열을 결정하기 때문이다. 따라서, 본 연구에서 개발된 EV ROM을 다양한 홍수사상에 적용, 예측강우량의 정확도 개선 및 프로그램의 보완이 이루어진다면, 현재보다 한차원 높아진 저수지운영을 기대 할 수 있을 것이다.

• 한국생산제조학회지
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• 제26권1호
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• pp.144-149
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• 2017

There have been lots of interest on service and entertainment robots. To ensure that robots work in harmony with humans, their stability and compactness are some of the key issues. Obviously, robots with fewer wheels occupy a smaller floor area compared to those with more wheels. In addition, robots with fewer wheels, whose posture stabilities are maintained by feedback control, are stable even under larger accelerations and/or higher locations of the center of mass. To facilitate controller design, it is assumed that both pitch and roll dynamics are decoupled. The dynamic equations of motion for the proposed robot are derived from the Euler-Lagrange equation. To obtain the optimal balancing control law, linear quadratic regulator control methods are applied to the linearized dynamic equations. Simulation and experimental results verify the effectiveness and performance of the proposed balancing control algorithm for a single-wheeled mobile robot.

• 재활간호학회지
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• 제5권1호
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• pp.38-48
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• 2002

The purpose of this study is to identify the effects of a nursing intervention using sensory stimulation in dysphagic patients. Quasi-experimental with a nonequivalent control group pretest-posttest design was used. 15 patients of each group were assigned for this study, who were hospitalized in the oriental medicine hospital of K. University. Specific stimulation plans were devised based on a dysfunctional area of the subjects. For each modality, subjects were systematically stimulated for 30 minutes, in the experimental group prior to each meal and 3 times per day for a week. The data were analyzed by SPSS PC program using $X^2$-test, Wilcoxon Signed Rank test and Mann-Whitney U test. The results of this study are as follows : 1. The tongue control score of the experimental group is greater than that of the control group(u=52.0, p=.007). 2. The score of chewing ability, lip control, swallowing ability of the experimental group is greater than that of the control group. But no difference is statistically seen between the experimental group and control group. Therefore, this study shows that sensory stimulation using icing, quick stretch, etc., was effective in improving or oropharyngeal function in patients with dysphagia.

• 한국운동역학회지
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• 제21권2호
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• pp.123-129
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• 2011

The purpose of this study was to compare and analyze the effect of twelve-week Taekwondo and walking exercises on the double-leg balance control by dividing elderly females into Taekwondo, walking exercise and control groups. In total, 30 elderly females were randomly divided into Taekwondo, walking exercise, and control groups, with 10 subjects in each group. Subjects participating in this study were 10(age $69.4{\pm}5.8$ years), 10(age $71.4{\pm}7.6$ years) and 10(age $70.6{\pm}4.8$ years) in the three groups, respectively. Although the AP measures were not significantly different among the groups and times, the ML RMS distance and ML velocity, among the ML measures showed a significant difference among the groups and times. Average velocity and 95% confidence ellipse area were also significantly different among the groups and times. Twelve-week Taekwondo and walking exercises were found to be effective in improving static balance control. Future studies on the development of a Taekwondo intervention program tailored for the elderly with many subjects conducted by using a long-term training program are expected.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.825-830
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• 2005

Traffic control is the center of the railway traffic control system. The main objective of railway traffic control system is to minimize delays, providing the customers with on-time train operating service according to the given train schedule. Particularly, within the station control area, the departure & arrival of train. the decision on the train priority and the shunting of train are decided by the authority of the local traffic controller. Therefore, it is necessary to have a lot of information and communications between each departments. And for such decision making of the local traffic controller, not only the communication between each stations are needed, but also the communication between other stations are needed too. In this paper, we have analyzed the main work of the local traffic controller in large scale stations and have designed the station traffic control system needed to be built within the station considering the local traffic. And we have proposed not only the communication with other system within station, but also the communication methods for communications with the neighboring stations.

• 한국전산유체공학회지
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• 제21권2호
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• pp.99-105
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• 2016

The present study has been carried out to analyze the flow characteristics with geometric shape and control conditions in subsea by-pass valve. The function of by-pass valve is to prevent reverse flow. In this study, the static analysis has been perform for analyzing fluid flow in open state. In order to consider the turbulent effect, the standard ${\kappa}-{\varepsilon}$ model was used. A variety of parametric studies, such as by-pass valve type or size, volume flow rate, leakage hole size, leakage hole position, block type, block shape, were performed. The pressure difference across the valve in the model broadened the flow channel cross-sectional area was greater than the base model for the same operating conditions. As the pipe diameter in the block decreases the pressure difference is greatly increased. The pressure difference according to block shape such as edge type and round was almost negligible. For the same Reynolds number the pressure difference was little changed according to the size of the valve.

• 대한한의학회지
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• 제24권4호
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• pp.19-24
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• 2003

Background and Purposes : Smoking is a well-known risk factor for ischemic stroke. It may contribute to s1Toke by inducing the aggregation of platelets and formation of atheroma, reducing cerebral blood flow, and increasing fibrinogen. However, the relative risk varies according to different ethnicity and area. Therefore, we performed this study to assess the risk of smoking for ischemic s1Toke in Korea. Methods : Cigarette smoking habit was studied in 308 patients with ischemic s1Toke and in 348 age- and sex-matched control subjects who had no history of stroke using case control methods. In multiple logistic regression analysis, smoking had a significant value of odds ratio adjusted for hypertension, diabetes mellitus, and hyperlipidemia. Results : The adjusted odds ratio (AOR) and 95％ confidence interval (CI) was significant in the medium smokers (AOR, 1.92; 95％ CI, 1.11 to 3.33: p< 0.05) and heavy smokers (AOR, 2.80; 95％ CI, 1.64 to 4.78: p< 0.05). Furthermore, the OR was higher in hypertensive subjects than in normotensive subjects compared to non-smokers (AOR, 1.98; 95％ CI, 1.01 to 3.85: p< 0.05). Conclusions : Our findings suggest that smoking is an independent risk factor for ischemic stroke in Korea.

• Journal of Biosystems Engineering
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• 제39권1호
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• pp.39-46
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• 2014

Purpose: Monitoring and control of environmental condition is highly important for optimum control of the conditions, especially in greenhouses and plant factories, and the condition is not uniform within the facility. Objectives of the study were to investigate variability in soil water content and to provide information useful for better irrigation control. Methods: Experiments were conducted in a strawberry-growing greenhouse (greenhouse 1) and a cherry tomato-growing greenhouse (greenhouse 2) in winter. Soil water content, electrical conductivity (EC), and temperature were measured over the entire area, at different distances from an irrigation pump, and on ridge and furrow areas. Results: When measured over the entire greenhouse area, soil water content decreased and temperature and electrical conductivity increased over time from morning to afternoon after irrigation. Water content decreased by distance from the irrigation pump up to 70 m and increased after that, and temperature showed an inverse pattern. Soil water contents on the ridge were lower than those on the furrow, and the differences were 10.2~18.4%, indicating considerable variability. The lowest EC were observed on the furrow and highest values were observed on the ridge. Soil water contents were less and temperature levels were greater at the window side than in the center locations. Conclusions: Selection of number and location of soil water content sensor would be the first step for better water content monitoring and irrigation control. Results of the study would provide basic data useful for optimum sensor location and control for underground greenhouse environment.