• Journal of Korean Academy of Nursing
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• v.35 no.2
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• pp.390-398
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• 2005

Purpose: This study was aimed at providing basic data for developing a nursing intervention program which enables systematic and correct visual acuity care by discovering out visual acuity conditions, prevalence rate of myopia, and the factors related to myopia with Preschool children. Method: The subjects of this study consisted of 519 children between 3 and 6 years of age from 12 kindergartens in Seoul which were selected through multiple cluster sampling. Myopia was defined as the spherical equivalent (SE) of more than -0.5 diopters (D) in the right eye. The data was analyzed by t-test, 2-test, ANOVA, and logistic regression by using the SAS program. Result: The prevalence rate of myopia was $8.7\%$. the odds ratio of child myopia when one parent had myopia was 2.2 times higher than when neither parent had myopia. The odds ratio of child myopia when reading more than three books per week was 0.27 times higher than reading less than three books. Conclusion: Myopia should be continuously and intensively managed from the age of 3.

• Journal of the Korean Chemical Society
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• v.60 no.6
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• pp.410-414
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• 2016

The anharmonic frequency of a local OH stretching mode of a water monomer and dimer was calculated using various levels of density functional theory. The quantum chemical potential energy curves as a function of the OH bond distance were calculated, and they were fitted with the Morse potential function to analytically obtain the fundamental transition frequency. By comparing those values with the frequencies similarly calculated using an ab initio quantum chemical method, the coupled cluster theory including both single and double excitations with the perturbative inclusion of triple excitation in the complete basis limit, the accuracy of various density functional methods in the calculation of anharmonic vibration frequency of water molecules was assessed. For a water monomer, X3LYP and B3LYP methods give the best accuracy, whereas for a water dimer, B972, LCBLYP, ${\omega}B97X$, ${\omega}B97$ methods show the best performance.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.389-395
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• 2004

We consider the interface between the parallel distributed memory multifrontal solver and the finite element method. We give in detail the requirement and the data structure of parallel FEM interface which includes the element data and the node array. The full procedures of solving a large scale structural problem are assumed to have pre-post processors, of which algorithm is not considered in this paper. The main advantage of implementing the parallel FEM interface is shown up in the case that we use a distributed memory system with a large number of processors to solve a very large scale problem. The memory efficiency and the performance effect are examined by analyzing some examples on the Pegasus cluster system.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2561-2564
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• 2003

Data mining is an effective method of the discovery of useful information such as rules and previously unknown patterns existing in large databases. The discovery of association rules is an important data mining problem. We have developed a new parallel mining called Distributed Frequent Pattern Tree (abbreviated by DFPT) algorithm on a distributed shared nothing parallel system to detect association rules. DFPT algorithm is devised for parallel execution of the FP-growth algorithm. It needs only two full disk data scanning of the database by eliminating the need for generating the candidate items. We have achieved good workload balancing throughout the mining process by distributing the work equally to all processors. We implemented the algorithm on a PC cluster system, and observed that the algorithm outperformed the Improved Count Distribution scheme.

• Asian Journal for Public Opinion Research
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• v.5 no.4
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• pp.266-284
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• 2018

This paper adopts the big data research method, and draws 491 data from the Tianya Forum about the Simultaneous Renting and Purchasing policy of Guangzhou. The qualitative analysis software Nvivo11 is used to cluster the main questions about the Simultaneous Renting and Purchasing policy in the forum. The 36 high-frequency word frequencies are obtained through text clustering. Through rooted theory analysis, the main driving factors for summarizing people's doubts are 9 main categories, 3 core categories, and the model of driving factors for online forums is established. The study finds that resource factors are the most key factor, economic factors are the important drivers, and policy guiding factors are sub-important drivers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1447-1454
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• 2006

The evaluation of parallel performance of a high speed impact simulation is not an easy task because not only the development of parallel explicit code is difficult but also a large number of processors is not easily accessible. In this paper, the parallel performance of a new Lagrangian FEM impact code carried out on cluster supercomputer has been described in high speed range. In the case of metal sphere impacting to oblique plate, the overall speed-up continuously increases even up to 128 CPUs. Investigation of elapsed time of each part reveals that most of the inefficiency comes from the load imbalance of contact.

• Annual Conference of KIPS
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• 2006.05a
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• pp.1231-1234
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• 2006

MANET에서 노드들은 DNS 서비스를 이용하기 위하여 DNS 서버를 구성해야 한다. 하지만 DNS 서버를 구성하는 노드는 다른 노드에 비해 많은 자원을 소비하게 되므로 DNS 서버는 주기적으로 교체되어야 한다. 따라서 본 논문은 클러스터링 기법을 활용하여 클러스터내의 노드들을 관리하는 CDNS 서버를 구성하고, 전체 CDNS 서버를 관리하는 RDNS 서버를 구성하여 네트워크의 모든 노드들이 DNS 서비스에 참여하는 분산 클러스터 기법의 DNS 시스템을 제안한다.

• Annual Conference of KIPS
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• 2006.05a
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• pp.1435-1438
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• 2006

일반적인 비 공유 저장장치를 가진 시스템에서는 특정 컨텐츠에 대한 편향된(skewed) 요청 문제를 피할 수 없다. 본 논문에서는 비 공유 저장장치 모델로 설계/구현된 클러스터 기반의 시트리밍 서버에서 사용자의 편향된 컨텐츠 요청에 대처할 수 있고 스트리밍 서비스 중인 서버 또는 NS 카드에 문제가 생기더라도 스트리밍 서비스가 중단되지 않도록 다중 스트리밍 방법인 MDC(Multiple Description Coding)를 적용한 스트리밍 전송방법을 제안한다. 제안하는 방법은 클러스터 시스템에서 단일 세션으로 스트리밍 서비스를 제공하는 것이 아니라 MDC 를 활용하여 다중 세션을 통한 스트리밍 서비스를 제공함으로써 모든 서버의 부하가 같아지고, 특정 서버에 문제가 발생하더라도 스트리밍 서비스가 끊어지지 않으면서 MDC 의 특성인 적응형 서비스도 가능하게 되는 장점이 있다.

• Journal of the Korean Institute of Landscape Architecture
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• v.22 no.2
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• pp.13-24
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• 1994

the purpose of this study was to suggest managemental strategies for one-day use recreational area in public sector under competitive environment with private sector. Data was collected from citizens of Seoul, and 10 recreational areas were determined by a preliminary survey. Theses areas were regarded as "products", then positioning was applied to these products. Perceptual map was produced by multidimensional scaling to identify degree of competition among areas. Properties, which were developed by the Kelly Repertory Grid, were utilized to understand the strong and weak points of each area. Ideal types of recreational areas were analyzed by PREFMAP, then the size and distribution of recreation market of Seoul were found by grouping of individual ideal point by cluster analysis. Several strategies were suggested to enhance the competitive power for public recreation areas, and a few comments were described to improve this method for future research.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.64-69
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• 1993

The aim of the present paper is to show the effectiveness of Genetic Algorithm for data classification problems in which the classification criteria are not the Euclidean distance. In particular, in order to improve a search performance of Genetic Algorithm, we introduce a concept of the degree of population diversity, and propose construction of genetic operators and the method of calculation for the fitness of an individual using the degree of population diversity. Then, we investigate their performances through numerical simulations.