• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.715-724
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• 2014

Tongdosa, which is located in Gajisan(Mt.) Provincial Park of Yangsan City, is one of three representative temple in Korea. The purpose of this study was to investigate a relation between plants community and environmental factors in Tongdosa(Temple) District of Gajisan(Mt.) Provincial Park. In order to find out vegetation structure of Gajisan(Mt.) Provincial Park, thirty one plots(unit size: $200{\sim}300m^2$) were set up and surveyed. For environmental factors, it were surveyed and analyzed physical factors such as altitude, aspect etc. and soil characteristics such pH, organic content, total nitrogen content, exchangeable cation and so on. Using DCCA technique, a relation between plants community and environmental factors were analyzed. The surveyed plots were divided into five groups which are Pinus densiflora - Quercus aliena, Carpinus tschonoskii - Q. spp., P. densiflora - C. tschonoskii, P. densiflora - Q. variabilis, and Q. variabilis - Q. mongolica community. Vegetation succession was progressed from Pinus densiflora toward Carpinus tschonoskii and Quercus spp. It was found out that the distribution of vegetation was affected by altitude. Pinus densiflora - Quercus aliena community is located lower altitude and Q. variabilis - Q. mongolica community is located higher area.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1175-1181
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• 2015

A heat insulating material used in the industrial site normally derives its heat insulating performance by using a low thermal conductivity material such as glass fiber. In case of the metal insulation for nuclear power plant, in contrast, only TP 304 stainless steel foil having high thermal conductivity is the only acceptable material. So, it is required to approach in structural aspect to ensure the insulation performance. In this study, the design factors related to the metal insulation internal structure were determined considering the three modes of heat transfer, i.e., conduction, convection, and radiation. The analysis of heat flow was used to understand the ratio of the heat transfer from each factor to the overall heat transfer from all the factors. Based on this study, in order to minimize the convection phenomenon caused by the internal insulation, a multiple foil was inserted in the insulation. The increase in the conduction heat transfer rate was compared, and the insulation performance under the three modes of heat transfer was analyzed in order to determine the internal geometry.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.170-174
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• 2008

Recently, a problem related to the thermal management in portable electronic and telecommunication devices is becoming issued. That is due to the trend of slimness of the devices, so it is not easy to find the optimal thermal management technology for the devices. From now on, a pressed circular type cooling device has been mainly used, however the cooling device with thin thickness is becoming needed by the inner space constraint. In the present study, the silicon and metal flat plate type cooling device with the separated vapor and liquid flow path was designed and fabricated. Through the experimental study, the normal isothermal characteristic by vapor-liquid phase change was confirmed and the cooling device with 70mm of total length showed 6.8W of the heat transfer rate within the range of $4{\sim}5^{\circ}C$/W of thermal resistance. In the meantime, the metal cooling device was developed for commercialization. The device was designed to have all structures of evaporator, vapor flow path, liquid flow path and condenser in one plate. And an envelope of that could be completed by combining the two plates of same structure and size. And the simplicity of fabrication process and reduction of manufacturing cost could be accomplished by using the stamping technology for fabricating large flow paths relatively. In the future, it will be possible to develop the commercialized cooling device by revising the fabrication process and enhancing the thermal performance of that.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.303-306
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• 2014

수많은 사람들이 게임을 제작 및 개발함에 있어, 많은 학자들이 다양한 방법으로 오랜 세월에 걸쳐 연구한 게임의 인문학적 정의 및 재미 이론은 현대의 게임 개발에 있어서도 그 이론적 배경을 담당하는 주춧돌의 역할을 맡고 있다. 본 논문에서는 청강문화산업대학교 게임전공의 게임 개발 프로젝트의 일환으로 구성된 '안드로메다' 팀이 Unity 3D 엔진을 기반으로 제작한 3D 생존 어드벤처 게임 "1 Hour"를 개발한 과정을 기술하였고, 그 과정에서 재미 이론의 '패턴'에 근거하여 플레이어로 하여금 몰입을 유발시키는 어드벤처 장르의 게임 디자인을 제시하는 것을 이번 연구의 목적으로 하였다. 연구 과정은 문헌 연구 및 개발 게임("1 Hour")의 플레이 테스트 등을 통해 게임에서의 몰입의 과정을 분석하였고, 몰입 유발 효과 증명을 위해 '패턴과 몰입의 상관관계'에 대한 가설들을 수립하고 실험을 실시하여 그 결과를 분석하였다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.167-175
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• 2013

The aim of this study is to evaluate the effect of cosmetic products containing concentrated ginseng using novel methods based on Traditional Korean medicine (TKM). In TKM, inspection of facial skin was an important method to diagnose symptoms and body condition of patients. Doctors in oriental medicine examined a patient as observing symptoms on the face and skin related to inner organs. This was called "mang-jin. In this study, eleven female, who have been using the cosmetic products containing concentrated ginseng for the last 5 years, and eleven healthy controls, who have never used the same product, were recruited. Three doctors in oriental medicine evaluated 17 inspection factors on facial skin. And 7 non-invasive skin bioengineering factors were assessed by various instruments at the same time. In results, 7 factors of the inspection were better in using the product than in controls. And sebum, roughness, pigmentation and wrinkle depth were significantly lower in using the product than in controls. So, this results propose that the cosmetic product containing concentrated ginseng has a good anti-aging effect on skin. And it is suggested that the novel evaluation method combined, Traditional Korean medicine and modern bioengineering technique, has to be developed for holistic concept of Hanbang cosmetics.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.8-14
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• 2009

In a laser-plasma wakefield accelerator, the ponderomotive force of an ultrashort high intensity laser pulse excites a longitudinal wave or plasma bubble in a way similar to the excitation of a wake wave behind a boat as it propagates on the water surface. Electric fields inside the plasma bubble can be several orders of magnitude higher than those available in conventional RF-based particle accelerator facilities which are limited by material breakdown. Therefore, if an electron bunch is properly phase-locked with the bubble's acceleration field, it can gain relativistic energies within an extremely short distance. Here, in the bubble regime we show the generation of stable and reproducible sub GeV, and GeV-class electron beams. Supported by three-dimensional particle-in-cell simulations, our experimental results show the highest acceleration gradients produced so far. Simulations suggested that the plasma bubble elongation should be minimized in order to achieve higher electron beam energies.

• Journal of dental hygiene science
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• v.16 no.1
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• pp.84-92
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• 2016

Cooperation of the patients in orthodontic treatment is an essential element. This study examines the internal and external restriction factors and level of cooperation for orthodontic treatment of adolescent orthodontic treatment patients, and the factors that impart influence on the level of cooperation for orthodontic treatment. 'Form for students' among the indices of internal and external restrictions for orthodontics, which is an adaption of 'Orthodontic Locus of Control Scale' was used as survey tool, and 'Reliability and Stability of the Orthodontic Patient Cooperation Scale' was used as survey tool for the level of cooperation of orthodontic patients. As the result of examination of the effect of internal and external restriction factors on level of cooperation for orthodontic treatment by compensating the general characteristics in the multiple regression analysis, it was found that the level of cooperation for orthodontic treatment is higher for the patients who believe there is strong influence of external restrictions-patents-on the events that determines orthodontic treatment. In order to enhance the level of cooperation for orthodontic treatment of adolescent orthodontic patients, there is a need to assess the relationship between the patient and parents as well as the attitude or psychological state of the patients on orthodontic treatment.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.123-129
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• 2017

This paper proposes a new nonnegative matrix factorization (NMF) based direction-of-arrival (DOA) estimation method for multiple sound sources using a dual microphone array. First of all, sound signals coming from the dual microphone array are segmented into consecutive analysis frames, and a steered-response power phase transform (SRP-PHAT) beamformer is applied to each frame so that stereo signals of each frame are represented in a time-direction domain. The time-direction outputs of SRP-PHAT are stored for a pre-defined number of frames, which is referred to as a time-direction block. Next, In order to estimate DOAs robust to noise, each time-direction block is normalized along the time by using a block subtraction technique. After that, an unsupervised NMF method is applied to the normalized time-direction block in order to cluster the directions of each sound source in a multiple sound source environments. In particular, the activation and basis matrices are used to estimate the number of sound sources and their DOAs, respectively. The DOA estimation performance of the proposed method is evaluated by measuring a mean absolute error (MAE) and the standard deviation of errors between the oracle and estimated DOAs under a three source condition, where the sources are located in [$-35{\circ}$, 5m], [$12{\circ}$, 4m], and [$38{\circ}$, 4.m] from the dual microphone array. It is shown from the experiment that the proposed method could relatively reduce MAE by 56.83%, compared to a conventional SRP-PHAT based DOA estimation method.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.47-65
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• 2014

VMS(Variable Message Sign) helps drivers to choose their path to destinations on roadways. Some types of VMS often provide traffic information with clearly visible and comprehensible graphical route diagrams. Currently many diagramed types of VMS are installed on urban arterial and highways. This type of VMS surely enhances drivers' ability to comprehend traffic route information while they are driving on the roadway. Nevertheless, some of them are presented with so much information and design elements and they sometimes lead to decline of drivers' comprehensible level for traffic information. Drivers would fail to decide their preferable route in this state of information overflow. The purpose of this paper is to develop a drivers preference model for effective design principle including size and height of displaying font, and the amount of information in the route diagram considering driving speed, sex and age of the driver. This model is developed using structural equation modeling techniques. This model considers driver's emotional factor and, human factor and design component of route diagram. To collect data, we built driving simulator which is able to replicate real driving condition. 72 people who participated in the simulation were selected considering gender and age. The developed model showed that the amount of information, and visibility are more influential factors to the drivers' preference of the route diagram on VMS than design elements such as the shape and the font of the diagram.

• Management & Information Systems Review
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• v.33 no.4
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• pp.21-38
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• 2014

This study investigates whether and how a firm's cost of equity is influenced by the extent of a firms's name change. Even though corporate name change doesn't give any benefit to investors, it can be a signaling about firm's future valuation. And also, if that signaling has high credibility, it can be decrease information cost and the firm's cost of equity. on the contrary to this, if corporate name change is kind of break with the past and corporate image laundering, it is bad signaling to investors. So it can be increase information risk and the firm's cost of equity. Using yearly cross-sectional regressions of the cost of equity on our proxies for corporate name change, size, beta, market-to-book ratio and other innate risk factor over the 2005-2010, we find that the cost of capital is positively associated with corporate name change after controlling for all other factors. This result implies that corporate name change increase information risk of the business, and thus increase information asymmetries between managers and outside investors with respect to a firm's true future value. This increases information risk, and creates an adverse selection problem, on the part of outside investors. Rational investors therefore demand a premium for bearing this corporate name change-related information risk, which in turn leads us to observe a positive relation between the intensity of corporate name change and the cost of equity.