• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.10-13
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• 2010

The flow field in road tunnel is influenced by some facts such as piston effect of vehicle's move, operation of ventilation facilities, natural wind and buoyancy effect of fire plume. Among those, jet fan is one of main ventilation facilities especially in longitudinal ventilation system of tunnel. In this study to analyze tunnel flow induced by operation of jet fan, numerical simulation has been carried out. The velocity distributions and streamlines in tunnel are examined to consider the three-dimensional characteristics of tunnel flow caused by jet fan.

• 동서간호학연구지
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• 제4권1호
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• pp.7-20
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• 1999

Operation usually brings about psychological stress as well as physical stress to the patient and it greatly influences the maintenance of the homeostasis. Until now, most of the nursing research concerning the anxiety of the patient undergoing an operation has been done while the patient was under general anesthesia. Under local anesthesia, the anxiety of the patient who undergone operation is short. However, there is much demand of the operational nurses to mediate between the patient who is undergoing operation when fully conscious, as they are aware of the patient's anxiety and to decrease the patient's anxiety of this local anesthesia. Therefore, this research tries to verify the effects of the Hand-holding program on the anxiety of the operational patient undergoing local anesthesia and affirms the role of the nursing intervention. As an unequivalent control group non-synchronized designs, this research selects out 20 control groups and 21 experimental groups at random who have received cataract operation while under local anesthesia and after implementing the Hand-holding program to the experimental groups while undergoing the operation, the effect of the experiment was observed. By observing the Epinephrine, Cortisol, blood pressure, and pulse for the physical indexes before and after the enforcement of the hand-holding, and using the measurement of Speilberger(1972) for the psychological indicators for the anxiety of the patient before and after hand-holding, the results were analyzed through SAS program. As a results, intervention of hand-holding had a remarkable effect to decrease the anxiety felt by the patient and the diastolic blood pressure also was effectively decreased. On the other hand, through the decrease of the systolic blood pressure was also observed, it was not statistically significant. In the Epinephrine and Cortisol indicators, the intervention of hand-holding was revealed to have an insignificant effect. The Hand-holding was revealed to have an indicators, the intervention of Hand-holding was revealed to have an insignificant effect. The Hand-holding program may be said to have an effect which decreases the psychological anxiety of the patient undergoing local anesthesia.

• Journal of Periodontal and Implant Science
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• 제31권4호
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• pp.765-775
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• 2001

The aim of the study was to investigate the effect of surgical therapy combined with the usage of metronidazole gel in the treatment of juvenile periodontitis by comparing clinical indices of flap operation along with application of metronidazole gel and flap operation only. Comparing clinical indices of the baseline, 3 months after surgery, 6 months after surgery statistically, the results are as follows; 1. Bleeding on probing (BOP) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p<0.05). BOP increased 0.9% in the control group 6 months after surgery, while in the experimental group, decreased 4.7% (p>0.05). However, there was no statistically significant difference in these groups (p>0.05). 2. Pocket probing depth (PPD) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p<0.05). PPD increased 0.lmm in the control group 6 months after surgery, while in the experimental group, no increase of the depth could be observed (p>0.05). However, there was no statistically significant and difference in these groups (p>0.05). 3. Loss of attachment level(LOA) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p<0.05). LOA increased 0.2mm in the control group 6 months after surgery, while in the experimental group, increased 0.3mm However, there was no statistically significant difference in these groups (p>0.05). In conclusion, flap operation was effective on the treatment of juvenile periodontitis. However, combined therapy of metronidazole gel could not give rise to any significant adjunctive effect on the treatment outcome.

• 대한기계학회논문집A
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• 제41권3호
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• pp.225-232
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• 2017

런너, 흡출관 등 양수발전소 수차 부속기기들에 캐비테이션 침식과 피로 균열 등의 손상 발생과 관련하여 많은 정비 사례들이 보고되고 있다. 양수발전소는 급전, 전력계통 안정 등과 같은 부수적 서비스를 제공한다. 이러한 부수적 서비스는 가이드 베인을 작게 열고 운전하는 저개도율 운전을 반복적으로 자주 수행하게 한다. 이러한 저개도율 운전은 수차 부속기기의 손상을 가속시키는 것으로 경험적으로 알려져 있다. 본 연구에서는 양수발전소의 가이드 베인 저개도율 운전이 수차의 캐비테이션과 피로를 가속시키는 효과를 유한요소 유동/응력 해석 및 피로 해석을 통해 정량적으로 평가한다. 평가 결과, 가이드 베인 개도율이 작을수록 캐비테이션 발생 가능성과 수차 효율 저하 가능성이 증가하며, 런너 블레이드 루트부에 최대 응력값을 증가시킴에도 불구하고 저개도율 운전이 피로수명에 미치는 영향은 미미함을 확인하였다.

• 전기학회논문지
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• 제58권9호
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• pp.1706-1713
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• 2009

In this paper, a parallel operation algorithm for high power PEMFC generation systems is proposed. According to increasing the capacity of fuel cell systems with several fuel cell stacks, the different dynamic characteristics of each fuel cell stack effect on imbalance of load sharing and current distribution, so that a robust parallel operation algorithm is desired. Therefore, a power-sharing technique is developed and explained in order to design an optimal distributed PEMFC generation system. In addition, an optimal controller design procedure for the proposed parallel operation algorithm is introduced, along with informative simulations and experimental results.

• 전기의세계
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• 제21권4호
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• pp.15-21
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• 1972

For the conventional DC machine, the armature MMF is negligible compared with field MMF except when the machine is under heavy load or transient conditions. During the motor starting or reversal, the transient armature current and corresponding MMF effect the flux density of each pole in the machine magnetic circuit. However, the circuit flux density is restored to normal values by the field winding MMF after the transient armature current dies in an electromagnetic DC motor. Permanent magnet servomotor have no field windings about the circuit poles to restore circuit flux density through the demagnetized part of each pole after the transient armature MMF dies, and portions of the magnetic circuit stay permanently demagnetized. Thus the problem of stabilizing a magnet pole piece under the influence of the transient armature current need attentions. This work present the recoil operation of the servomotor with PM poles in conjunctions with the influence of the armature reaction effect. The development of an analytical and quantatative study is presented for predicting the regime of the recoil operation under this condition.

• 산업융합연구
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• 제14권2호
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• pp.39-46
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• 2016

The purpose of this Study is to present the tasks and means of improving the operational system of public culture and arts institutes in the future on the basis of the analysis of the effectiveness of operation of public culture and arts institutes. The summary of the results of analysis in this Study is as follows: Firstly, it was found that the factor variables that impart effect on the operation of public culture and arts institutes included (1) artistic value, (2) convenience and (3) organizational management, while the performance variable of public culture and arts institutes was (4) operational performance. Secondly, in the analysis of the structure that explains the operational effects of public culture and arts institutes, convenience and organizational management were found to impart effects on the operational performances. However, artistic value was found to have no effect on operational performances. Therefore, these results of analysis imply that organizational management and convenience, rather than artistic value, need to be fortified in order to elevate the operational performances of public culture and arts institutes.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.795-802
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• 2007

미 국방성은 미래 전장에서 네트워크화를 통한 전투 능력의 시너지 효과 증대를 도모하고 있다. 특히 Joint 2020에서는 전장에서 작전 수행시 합동군의 지식 우위와 결심 우위를 위한 정보 우위를 추구하고 있다. 본 연구에서는 미국을 중심으로 하는 네트워크 중심 작전에 대한 개념과 운용 사례를 살펴보고 작전운용 거리에 대한 정량적인 거리와 영향, 통신중계 성능을 분석하였다.

• 반도체디스플레이기술학회지
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• 제12권4호
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• pp.9-13
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• 2013

Lapping is a very complicated and random process resulting from the variation of abrasive grains in its sizes and shapes and from the numerous factors having an effect on the process quality. This paper presents a study of a $2^4$ full factorial experimental design and analysis to optimize surface quality in lapping operation. The optimization of the factors to obtain minimum surface roughness was carried out by incorporating effect plots, main effect plots, interaction plots, analysis of variance(ANOVA), surface plots, and contour plots. The statistical design experiments, designed to reduce the total number of experiments required, indicated that, within the selected conditions, all the parameters influenced at a significance level of 5%. In addition, some of the possible interactions between these parameters also influenced the lapping process, especially those that were of third order. A regression model was suggested and fitted the experimental data very well.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1594-1598
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• 2007

Energy saving is an important topic for each heavy user of the power system, including railway operators. Therefore, four strategy of train operations studied that maximum speed reduction, reduced acceleration rate, anticipatory coasting, and saw-tooth coasting for energy saving. The Simulation model of the study used to investigate the performance of a railway system, and it was used to study the effect of energy saving strategies for the train operation. The Study investigate train operation strategy for energy saving, investigate the effect of strategy, and find the energy optimization of acceleration, coasting, braking section used Run-Curve simulator from train data.