• Journal of Korea Society of Industrial Information Systems
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• v.19 no.2
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• pp.37-43
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• 2014

In this paper, we present the effect of forward current gain on emitter area in NPN transistors are used widely in the almost linear integrated circuits and integrated injection logic. Relations between forward current gain and emitter area were conformed with the simulation with examined calculation and experiments. At the same emitter length, as junction depth is increased, common emitter current gain is decreased. Ratio of Emitter bottom area comparing to side area increases, the emitter current gain is increased. The theory and simulation results were fitted in with the experimental data very well.

• Journal of the Korean Society of Radiology
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• v.10 no.6
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• pp.435-442
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• 2016

This study was an investigation of the anode heel effect caused by changing the angle of the x-ray tube. We established the following conditions for experimental measurements: 70 kV, 30 mAs, focus-detector distance of 100cm, and a collimator setting of $35{\times}43cm^2$. The measurement points were set up at the center of the collimator and extended to each side in intervals of 3.5cm, with points A1, A2, A3, A4, A5, A6 on the anode side and points C1, C2, C3, C4, C5, C6 on the cathode side. We measured the entrance surface dose from point A6 to point C6 with each point perpendicular to an x-ray tube. And we did the same when measuring different angles of the x-ray tube from 15 to 30 degrees for every point on the anode and cathode sides. Using perpendicular x-ray tube, we found that the entrance surface dose of the A5 point was three times higher than that of the C5 point. Thus, we conclude that if the anode side is placed near highly radiosensitive organs, then there will be less radiation exposure when using a perpendicular x-ray tube. When imaging using x-ray tube angles, an angle to the cathode side can reduce the gap of the entrance surface dose on both the anode and cathode sides. When imaging areas where there are differences in thickness between the upper and lower sides, the angle to the cathode side that is closer to the thicker area can reduce the gap of the entrance surface dose and capture a higher quality image.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.2
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• pp.126-139
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• 2007

In the autumn of 2000 and spring of 2001, field surveys were conducted to estimate the effectiveness of artificial reefs (type cube, $2{\times}2{\times}2m^3$) that were established in the four islands of Bangnyeong, Socheong, Daeyeonpyeong and Ganghwa in Kyonggi Bay, the west coast of Korea during 1995 and 1996. The condition of reefs was examined through SCUBA diving and a side-scan sonar. Much of the reefs in Daeyeonpyeong and Ganghwa area were buried in bottom sediment. Despite an intensive search in Bangnyeong area, even a cluster of reefs was not found and most of them seemed to be buried by sand waves. Thus an appropriate investigation on the sediment transport should be included in pre-assessment for the expected performance and protection of artificial reefs. Distribution of average CPUE in natural fishing ground (control) was estimated by bootstrapping simulation and possible comparison of CPUE between control and reef areas (treatment) were made in Bangnyeong and Socheong (Experiment I). Positive reef effect was detected in Socheong but CPUE of treatment in Bangnyeong was varied between or lower than the 99% CPUE confidence intervals of the control. Control/treatment abundance and biomass of fishes and invertebrates were tested by paired t-test and sign test (Experiment II). Only four cases among 22 showed significant positive effect. Based on the results, the cube artificial reef in Socheong was inferred as an affirmative one. Floor type was hypothesized to be one of the probable agents in determining the effectiveness of artificial reefs.

• Journal of Oral Medicine and Pain
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• v.17 no.2
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• pp.27-35
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• 1992

The purpose of this study was to evaluate the size of the temporomandibular joint space by the increase of the occlusal force on the working side and the non-working side during unilateral biting. For the study, 22 normal adults, age from 23 to 25, who had normal or class I molar relationship and had no symptoms on TMJ area and masticatory muscles were selected. Transcranial TMJ radiograph was taken during unilateral biting with the sensor of occlusal load measuring device (MPM-3000 ; Nihon Kohden Kogyo Co. Ltd., Japan) on 1st molar teeth of right and left side given to force of 0kg, 10kg, 20kg and 30kg respectively with Accurad-200(Denar Corperation's product). The radiographs were traced on the screen, with enlaged as 5 times. The size of temporomandibular joint space at anterior, superior and posterior compartment were measured with Dumas's method (reference line between squamotympanic fissure and the lowest point of articular eminence). The following results were obtained by this study. 1. The size of anterior TMJ space showed a tendency to decrease on the working side and increase on the non-working side by the increase of the occlusal force, but had no statistical significancy (P>0.05). 2. The size of superior TMJ space showed a tendency to increase on the working side and decrease on the non-working side by the increase of the occlusal force (P<0.05). 3. The size of posterior TMJ space showed a tendency to decrease on both working and nonworking side, but had no statistical significancy (P>0.05)

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.859-872
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• 1996

The purpose of this study was to evaluate the effect of low concentrative ${\beta}-APN$ on the periodontal ligament and relationship between lathyrintic bodies and osteoclast cells near the by alveolar bone. Mandibles including teeth and periodontiums of 24 Sprague-Dawley rat was used. ${\beta}-APN$ 0.2g/kg/day soluted in mineral water was administrated for 5 days before sacrifice in experimental group. 3 rats on each day was sacrificed on 1, 3, 7, 11 days after stop administration ${\beta}-APN$. Histologic examination and the activity of osteoclasts by tartrate resistant acid phosphatase was observed. The results were as follows : 1. In experimental group, the The small foci of lathyrintic bodies surrounded by palisading fibroblasts were seen obviously on 1, 3 days and decreased after 7 days. On 11 days, fibroblasts of periodontal ligament similar to control group. 2. The lathyrintic bodies were seen in the middle zone of periodontal ligament of pressured area like furcation area, alveolar crest, bone resorption area than tensioned area of apposition area. 3. In experimental group of 1, 3 days, lathyrintic bodies were much seen in the area that osteoclasts was much distributed area. After 7 days, experimental group was seen the control group. In conclusion, rathyrintic bodies were formed by low concentrative ${\beta}-APN$ chiefly on the pressured area like furcation area, alveolar crest, bone resorption area than tensioned area of apposition side in periodontal tissue and concerned with osteoclast cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.406-412
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• 2014

To evaluate the influence of burrowing substrate on the rearing performance and ambicoloration of cultured flounder, Paralichthys olivaceus, we compared the daily food intake (DFI), feed efficiency (FE), survival, growth, proportion of pigmented skin on the blind side, and proportion of ambicolored fish. We reared juvenile flounders [total length (TL) $4.46{\pm}0.06cm$, body weight (BW) $0.77{\pm}0.03g$] in dark-green fiberglass-reinforced plastic (FRP) aquariums without (control) or with gravel substrate at a density of 200 fishes/ton for 120 days. While there was no difference in survival rate or growth, the DFI was lower and FE higher in the group raised with substrate than in the control. The proportions of pigmented area on the blind side and ambicolored fish were significantly higher in the control tank. Therefore, the supplement of substrate on the aquarium bottom positively affects the feeding efficiency, and inhibits abnormal pigmentation on the blind side in flounder farming at high density.

• Journal of Information Technology Services
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• v.15 no.2
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• pp.93-106
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• 2016

Recently, Open Course Ware service area which offers free lecture materials has been steadily growing. This change comes from a paradigm shift of education service caused by the progress of ICT and a role change of consumers. Knowledge creation from higher educational institutions is slow compared to change of society. Therefore, consumers escape from one-sided education, and perform a new role of knowledge generation. Nevertheless, there is not much of academic research of Open Course Ware. Consequently, the paper is dedicated to empirical study on effect of perceived value, information system quality and brand trust on intention to continuous use. As implications for the research, as a practical point of view, the results-an economic side that offers contents for free of charge, a contents side that is fresh, various and substantial, a systematic side that makes customers to use the system easily, a service side which takes charge of customers support and brand trust affect satisfaction and intention to continuous use - can be used for establishment of executive strategies.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.129-138
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• 2008

This study was carried out to examine the growth condition of Chionanthus retusa, roadside tree in Cheongyechon (CGC) and to investigate the relationship soil characteristics and tree vitality and chlorophyll contents of it. Growth condition of tree (condition of flower, leaves and branch, % of flowering, height, diameter at breast height, width, vitality and chlorophyll contents) and physiochemical relation item (pH, organic matter, K, Mg, Na, Ca, P) were investigated. The result are as follows : 1. The growth condition of flower, leaves and branch in the left side of CGC is better than the right side since the quantity of sunshine of left side of CGC is much more than the right side. 2. The average pH was alkaline. P and organic contents were much lower than the standards. 3. Tree vitality and chlorophyll contents were bad where were high user density and high buildings, such as 1, 2 area near Jong-gak and jongro 3 ga. Among the physiochemical factors of soil which affect tree vitality, K and P were found to be the main factors. Therefore, in order to improve the growth environment of roadside tree in CGC, it is needed to do periodical soil fertilizing and improve physical characteristics of soil such as, permeability and porosity by soil conditioner.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.384-386
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• 2003

Striking in change that present our country is much by electricity industry reform and the Korea Electric Power Corporation is deciding power distribution system reliability indices every year but power distribution system for reliability evaluation and establishment of investment program are consisting punily. If consider efficient inflection of resources and hereafter power distribution division that is limited for target achievement of schedule level service evaluation and reliability side in operation of the power distribution system, can expect efficient practical use of the power distribution property if gains in electrical side about these change and most suitable investment way consist because there is necessity of electric power plan establishment of area electric power distribution place of business unit. This paper consider proper reliability level and maximum effect through quantitative analysis to gain electrical gains of the power distribution system in reliability side depending on trend DB(Data Base) of data of electric power system composition appliance in this treatise and apply data administration and reliability rate analysis that serve to decide most suitable investment precedence to supply of electric power property to power distribution system present investment algorithm.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.1
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• pp.87-94
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• 2012

Purpose : The purpose of this study was to examine the feasibility and efficiency of balance training program through an interactive video game regimen in people with chronic stroke. Methods : Thirty patients with chronic hemiparetic stroke were recruited. Participants were randomly assigned to either a control group (n=15) or an experimental group (n=15). The control group received the general physical therapy including of strengthening and balance exercise five times a week whereas the experimental group received a program of balance exercise with video game play based on virtual reality as well as the same typical physical therapy. The experimental group received 6 sessions for four weeks. Each session was given 5 minutes. An interactive computer game exercise regimen lasted 30 minutes without rest periods. Outcome measures for weight transfer to paretic side, non-paretic side and sit-squat-speed, sit-squat-length, sit-to-standspeed and sit-to-stand-area for the control group (n=15) and experimental group (n=15) before and after treatment were obtained by using the biorescure. Results: Outcomes demonstrated significant improvement in the experimental group compared with the control group in weight transfer to paretic side, non-paretic side and sit-squat-speed, sit-squat-length, sit-to-stand-speed. No significant training effect was showed in sit-to-stand-area between pretraining and post-training. Conclusion : An interactive computer game exercise based on task oriented approach for balance in chronic stroke were feasible. In other words, This regimen resulted in a greater improvement in dynamic balance for people with chronic stroke.