• Journal of KIISE:Software and Applications
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• v.26 no.12
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• pp.1418-1427
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• 1999

시간지원 데이타베이스 시스템은 자료의 과거 및 현재, 그리고 미래의 상태까지 관리함으로써, 사용자에게 시간에 따라 변화하는 자료에 대한 저장 및 질의 수단을 제공한다. 시간지원 데이타베이스는 경향 분석, 버전 관리, 의료 기록 관리 및 비디오 데이타 관리 등과 같이 자료의 시간적 특성이 중요시 되는 모든 분야에 폭 넓게 응용될 수 있다. 시간지원 데이타베이스에서의 집계는 시간 애트리뷰트를 고려하지 않은 기존의 집계와는 큰 차이가 있으며, 기존의 집계 처리 기법을 이용하여 효과적으로 처리될 수 없다. 본 논문에서는 시간지원 집계를 효율적으로 처리하기 위한 새로운 자료 구조인 PA-트리를 제안하고, 이를 이용한 시간지원 집계 처리 기법을 제안한다. 또한 본 논문에서는 제안된 PA-트리를 이용한 기법과 기존의 집계 트리를 이용한 기법의 성능을 최악 경우 분석과 실험을 통해 비교한다.Abstract Temporal databases manage time-evolving data. They provide built-in supports for efficient recording and querying of temporal data. Many application area such as trend analysis, version management, and medical record management have temporal aspects, and temporal databases can handle these temporal aspects efficiently. The aggregate in temporal databases, that is, temporal aggregate is an extension of conventional aggregate on the domain and range of aggregation to include time concept. The basic techniques behind computing aggregates in conventional databases are not efficient when applied to temporal databases. In this paper, we propose a new tree structure for temporal aggregation, called PA-tree, and aggregate processing method based on the PA-tree. We compare the PA-tree with the existing aggregation tree which has been proposed for temporal aggregate.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.299-308
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• 1999

How the society perceives National Park plays the most important role to achieve the goal for the National Park, which is to protect the ecosystems in the park. The survey for the visitors to Soraksan National Park was conducted to search for the answer to the question. As a result of the analysis based upon the perception types derived from the survey and factors affecting those types, the National Park can be explained by emotionally oriented type(scenic beauty), culturally oriented type, recreation oriented type, and economically oriented type. The first three types are strongly rooted in traditional culture, whereas the fourth type always conflicts with the goal of ecosystem protection. Korea has a long way to go to be familiarized with both the concept of ecosystem protection required by IUCN(The World Conservation Union) and the environmental ethics approach popularly promoted in the western world. The long term strategy for the protection of natural ecosystem should be approached in a manner that the traditional culture can be integrated into all aspects of park management.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.1-17
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• 2015

In domestic game market, the video game market is getting smaller and also decreasing funds and high level developers. So we need the software that can help us to make more realistic and high quality contents by non-expert developer in poor environments. In this paper, we selected global studio's animations which were scored good evaluation by public and critics as a well-made emotional expression that can convey the emotion properly. We selected movements that express emotions from the animation scripts by using Ekman's 6 basic emotions and Greimas' dynamic predicate, and then we had analyzed and categorized with the data. We also analyzed the movements for which data we needed to create specific movements to express emotions by using 'Animation Layer' that used in Unity's blending process. And suggest concept of the program that to create the emotional expression movements by using those analyzed data.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.3
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• pp.92-98
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• 2017

The rapid growth of engineering technology and the emergence of systemized and large-scale engineering systems have resulted in complexity and uncertainty throughout the lifecycle activities of engineering systems. This complex and large-scale engineering system consists of numerous components, but system failure can be caused by failure of any one of a number of components. There is a real difficulty in managing such a complex and large-scale system as a part. In order to efficiently manage the system and have high reliability, it is necessary to structure a system with a complex structure as a sub-system. Also, in the case of a system in which cause of failures exist at the same time, it is required to identify the correlation of the components lifetime and utilize it for the design policy or maintenance activities of the system. Competitive risk theory has been used as a theory based on this concept. In this study, we apply the competitive risk theory to the models with combined structure of series and parallel which is the basic structure of most complex engineering systems. We construct a competing risks model and propose a mathematical model of net lifetime and crude lifetime for each cause of failure, assuming that the components consisting a parallel system are mutually dependent. In addition, based on the constructed model, the correlation of cause of failure is mathematically analyzed and the hazard function is derived by dividing into net lifetime and crude lifetime.

• Journal of Integrative Natural Science
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• v.3 no.4
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• pp.226-230
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• 2010

Calculation of partial charge is important in chemistry. However, because there are many methods developed, it is of considerable interest to know how to calculate and apply properly to address various chemical problems. For basis set, usually double zeta quality is acceptable, and double zeta polarization function would be enough for most cases. To describe electronic state more accurately, Many electron configurations would be necessary to describe highly strained or anionic species. The NPA population introduced new concept about amide bonds, i.e., the planar geometry of nitrogen atom may not come from resonance, but from the lowering of p-orbital energy by electronegative carbonyl carbon atom. The issues for hypervalent atomic charges was also addressed by various charge derivation scheme. When the charge schemes were applied to organolithium compounds, the ionic nature of boding was revealed. This comes from the fact that previous Mulliken partial atomic charges overemphasized the covalent character, wihout much justification. The other partial charge derivation schemes such as NPA(natural population analysis), IPP (Integrated Projected Population) showed that much more ionic picture. ESP potential derived charges are generally believed to be suitable to describe intermolecular interactions, therefore they are used for molecular dynamics simulations and CoMFA (comparative molecular field analysis). The charge derivation schemes using multipole polarization was mainly applied to reproduce experimental infrared spectroscopy. In some reports these schemes are also suitable for intermecular electrostatic interactions. Charges derived from electron density gradient have shown the some bonds are not straight, but actually bent. The proper choice of charge-calculation method along with suitable level of theory and basis set are briefly discussed.

• The Journal of Fisheries Business Administration
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• v.49 no.1
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• pp.67-89
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• 2018

In fisheries, as well as in other natural resource-based industries, there is difference between profit and rent. The former is a basic indicator for gauging the business performance of firms, while the latter is for the evaluation of the contribution of resources and industry to economic welfare. Put simply, resource economists are mainly concerned about rent, including pure resource rent and producer surplus (intra-marginal rent [IMR]). In other hand, business economists are mainly concerned about the profitability of the firms comprising the industry. In the academic literature, there are not always clear definitions of the profit and rent concepts and their use in actual analyses. This article will mainly discuss and clarify differences and similarities in profit and rent concepts. In the classical fisheries economic model with one-dimensional homogenous effort and a constant cost per unit of effort, no rent exists in open-access equilibrium. A simple change in this model, for example by introducing heterogeneous effort, opens it to the existence of rent, specifically IMR, at open-access equilibrium. We estimated resource rent and profit from the data using SNA(system of national accounts) and accounting data methods. RR(resource rent) is composed of value-added, compensation of employees, consumption of fixed capital and normal profit in SNA. RR(resource rent) is composed of EBT, Depreciation of fishing rights, financial costs of fishing rights and calculated interests on equity in accounting data methods. We found that the result of two methods is equal. RR is composed of excess profit, rent and interest expenses. In Korea, the magnitude of RR and profit is not different significantly.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.423-431
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• 2016

Customizing system is known as an important factor which affects not only purchase, loyalty and immersion of the user. In this study, we explore the concept of character-customizing system in the early stage of a game; on the basis of it, we compare cases by analyzing and schematizing certain types of systems which many games stick to. Customizing system types are divided into a basic case and a differentiated convergence case; based on it, they are classified into four types: Realistic, Creation, Individual, Additional; plus, another customizing system case out of games is also analyzed. To improve customer loyalty, a system like a differentiated case that attracts user participation is essential. Through a variety of character customization convergence cases shown in this study, we expect them to be used as game production guides. By enlarging the range of the study, we expect further studies to cover more cases.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.235-245
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• 2020

This study was a literature review to investigate the trends and characteristics of music intervention studies on psychological support for children and adolescents from multicultural families. A total of 19 researches(13 theses and 6 articles) from 2009 to 2018 was reviewed through the selection and exclusion criteria. First, in the general characteristics, researches employing quasi-experimental design and those of one-group pre-post tests scored a higher ratio, and studies for children under the age of 13 also showed the highest percentage. Second, about the intervention characteristics, the goal mainly focussed on self-related factors such as self-identity, self-esteem and self-concept, and with the intervention type, there were mostly found the group activities integrating singing, playing and creating. It is meaningful that this study can be used as basic data developing music intervention programs for them, and suggesting music intervention considering the characteristics of them will be conducted more actively in the future.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.11-18
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• 1998

A binary line code, called MB46d, is designed by use of the BUDA(Binary Unit DSV and ASV) cell concept to retain the property of being runlength limited, DC tree, and with a power spectral null at the Nyquist frequency. This new code is a stateless line code with a simple encoding and a decoding rule and enables efficient error monitoring. The power spectrum and the eye pattern of the new line code are simulated for a minimum-bandwidth digital transmission system where the sinc function is used as a basic pulse. The obtained power null at the Nyquist frequency is wide enough to enable easy band-limiting as well as secure insertion of a clock pilot where necessary. The eye is also substantially wide to tolerate a fair amount of timing jitter in the receiver.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.4
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• pp.27-31
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• 1990

To calculate the lift of a thin lifting surface like the ship-rudder, it is popular to replace the lifting surface by a series of vortices. Two methods, which are vortex lattice method and mode function method, are frequently used to distribute the vortices on the lifting surface. In this paper, the intermediate way of two mentioned calculation method is carried out to exploit the merits of them. The basic concept of this method is to divide the lifting surface with several strips in span-wise and replace vortices to the chord-wise at each strips. A horn type semi-balanced rudder is chosen for the real method, and the validity of the proposed calculation is pursued by the open water test of the same rudder. Finall, this method is applied to the calculation of the interference between the two homogenous rudders siting parallel to the free stream.