• Journal of information and communication convergence engineering
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• 제2권1호
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• pp.26-31
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• 2004

In the last few years, The Semantic Web has increased the interest in ontologies. Ontology is an essential component of the semantic web. Ontologies continue to change and evolve. We consider the management of versions in ontology. We study a set of changes based on domain changes, changes in conceptualization, metadata changes, and temporal dimension. In many cases, we want to be able to search in historical versions, query changes in versions, retrieve versions on the temporal dimension. In order to support an ontology query language that supports temporal operations, we consider temporal dimension includes transaction time and valid time. Ontology versioning brings about massive amount of versions to be stored and maintained. We present the storage policies that are storing all the versions, all the sequence of changed element, all the change sets, the aggregation of change sets periodically, and the aggregation of change sets using a criterion. We conduct a set of experiments to compare the performance of each storage policies. We present the experimental results for evaluating the performance of different storage policies from scheme 1 to scheme 5.

• Computers and Concrete
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• 제2권3호
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• pp.239-248
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• 2005

The article presents the results of examination of the fractal dimension D of concrete specimen fracture surfaces obtained in fracture toughness tests. The concretes were made from three different types of coarse aggregate: gravel, dolomite and basalt aggregate. Ordinary concretes (C40) and high-performance concretes (HPC) were subjected to testing after 7, 14, 28 and 90 days of curing, respectively. In fracture toughness and compressive tests, different behaviours of concretes were found, depending on the type of aggregate and class of concrete (C40, HPC). A significant increase in the strength parameters tested occurred also after a period of 28 days (up to the $90^{th}$ day of curing) and was particularly large for concretes C40. Fractal examinations performed on fracture replicas showed that the fractal dimension D was diverse, depending on the coarse aggregate type and concrete class being, however, statistically constant after 7 and 14 days for respective concretes during curing. The fractal dimension D was the greater, the worse strength properties were possessed by the concrete. A cross-grain crack propagation occurred in that case, due to weak cohesion forces at the coarse aggregate/mortar interface. A similar effect was observed for C40 and HPC made from the same aggregate. A greater dimension D was exhibited by concretes C40, in which case the fracture was easier to form compared with high-performance concretes, where, as a result of high aggregate/mortar cohesion forces, the crack propagation was of inter-granular type, and the resulted fracture was flatter.

• 대한간호학회지
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• 제18권2호
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• pp.189-196
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• 1988

Health, a major concept in nursing, has not yet consistent or agreed upon definition. Although effective health care depends on clear communication between health care provider and client clear definition of health would enhance the promotion of quality in health care. There are no agreed definitions or criteria for overall health. An essentialstep would seem to be to determine commonly held meaning about the concept of health. Therefore, the study was aimed at identifying the Adult's perceptions of health concept. The subject's consisting of 312 adults, who were sampled through area sampling from May 10 to May 30,1988. The instruments used for this study were Health Conception Scale, which was developed by Smith, Laffrey's revised and tested its reliability. The data was Analyzed by S.P.S.S. program and the results were as follows ; 1. The results of the reliability test for content of health concept was $\alpha$＝.87. 2. The respondents perception of Health Meaning were inclined to emphasize the functional / role performance dimension rather than clinical dimension. 3. The perceptual level of health concept was proved to be significantly different by the variable : age, sex, religion, area marital status. In conclusion, adult's perception of Health Concept is revealed that functional and role performance dimension is more important than other dimensions. Futher study is necessary to clarify the structure of functional, adaptive, eudaimonistic dimension and systematic study with subculture will be and repetitive verification and modification of this tool is demanded.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1308-1311
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• 2004

It is very important that get polishing characteristic that to be stable that accomplish planarization of high efficiency in chemical mechanical polishing, and there is repeatability Groove of pad causes much effects in flow of slurry among various factors that influence in polishing characteristic, is expected to cause change of lubrication state and polishing characteristic in contact between wafer and pad. Therefore, divided factors of pad groove by groove pattern, groove profile, groove dimensions. This research wishes to study effect that dimension of pad groove gets in polishing performance. When changed dimension (width, depth, pitch of groove) of groove, measured change of removal rate and friction force. According as groove dimension changes, could confirm that removal rate and friction force change. While result of this experiment studies effect of pad groove in CMP, it is expected to become small help.

• 대한설비공학회지:설비저널
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• 제17권4호
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• pp.408-417
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• 1988

This study optimized the condenser dimension of heat pump system with the heat sources which are solar irradiation and ambient air. At first, the author selected the principal design factors influencing the performance of heat pump system. And the author considered the variation of condenser dimension according to the variation of the selected design factors, that is, ambient air temperature, condenser temperature, degree of superheating, degree of sub-cooling and irradiation. As a result this study, among refrigerants R12, R22 and R500, refrigerant R22 has more heating output than R12 and R500, and the coefficient of performance on this heat pump system is not greatly influenced by the degree of superheating and degree of sub cooling. The ambient air temperature is below $5^{\circ}C$ at balance point and the optimal tube length of condenser dimension is about 3.8 m. Also the author gained the optimal design diagram for the optimization of condenser dimension according to various design factors.

• 제어로봇시스템학회논문지
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• 제7권5호
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• pp.445-453
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• 2001

The multiple targets tracking problem has been one of the main issues in the radar applications area in the last decade. Besides the standard Kalman filtering, various methods including the variable dimen-sion filter, input estimation filter, interacting multiple model(IMM) filter, dederated variable dimension filter with input estimation, etc., have proposed to address the tracking and sensor fusion issues. In this pa- per, two existing tracking algorithm, i.e, the IMM filter and the variable dimension filter with input estima-tion(VDIE), are combined for the purpose of improving the tracking performance for maneuvering targets. To evaluate the tracking performance of the proposed algorithm, three typical maneuvering patterns, i.e., waver, pop-up, and high-diver motions, are defined and are applied to the modified IMM filter as well as the standard IMM filter. The smaller RMS tracking errors, in position and velocity, of the modified IMM filter than the standard IMM filter are demonstrated though computer simulations.

• 정보관리학회지
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• 제19권3호
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• pp.237-261
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• 2002

본 연구는 기대와 성과간의 비교를 통하여 이용자 관점에서 도서관 온라인 서비스에 대한 품질을 평가하였다. 이를 위해 22개 SERVQUAL 문항에 정보품질에 관련된 7개 항목을 추가하여 총29개의 측정항목을 개발하였고, 대덕연구단지내의 한 연구 도서관을 대상으로 온라인 설문을 실시하여 데이터를 수집하였다. 요인분석 결과 온라인 서비스의 품질을 결정하는 요소인 서비스차원은 5개로 묶여졌고, 정보품질 차원은 별개로 분리되어 나타났다. IPA(Importance Performance Analysis) 분석결과 정보품질, 신뢰성, 그리고 보증성이 중요한 서비스 요소임이 밝혀졌고, 다중회귀분석 결과 이용자의 만족에 가장 커다란 영향을 미치는 서비스 요소로는 유형성과 정보품질인 것으로 규명되었다.

• 한국통신학회논문지
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• 제35권7A호
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• pp.623-631
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• 2010

In this paper, various of pilot-assisted channel estimation techniques for 3GPP LTE downlink are tested under multipath Rayleigh fading channel. At first, the conventional channel estimation techniques are applied with linear zero-forcing (ZF) equalizer, such as one dimensional least square (1-D LS) linear interpolation, two dimensional (2-D) wiener filter, the time and frequency dimension separate wiener filter and maximum likelihood estimator (MLE). Considering the practical implementation, we proposed two channel estimation techniques by combining time-dimension wiener filter and MLE in two manners, which showed a good tradeoff between system performance and complexity when comparing with conventional techniques. The nonlinear decision feedback equalizer (DFE) which can show a better performance than linear ZF equalizer is also implemented for mitigating inter-carrier interference (ICI) in our system. The complexity of these algorithms are calculated in terms of the number of complex multiplications (CMs) and the performances are evaluated by showing the bit error rate (BER).

• 전자공학회논문지B
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• 제33B권3호
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• pp.169-175
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• 1996

In this paper, a new parallel neural network system that performs dynamic competitive learning is proposed. Conventional learning mehtods utilize the full dimension of the original input patterns. However, a particular attribute or dimension of the input patterns does not necessarily contribute to classification. The proposed system consists of parallel neural networks with the reduced input dimension in order to take advantage of the information in each dimension of the input patterns. Consensus schemes were developed to decide the netowrks performs a competitive learning that dynamically generates output neurons as learning proceeds. Each output neuron has it sown class threshold in the proposed dynamic competitive learning. Because the class threshold in the proposed dynamic learning phase, the proposed neural netowrk adapts properly to the input patterns distribution. Experimental results with remote sensing and speech data indicate the improved performance of the proposed method compared to the conventional learning methods.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제12권1호
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• pp.1-5
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• 2012

Data reduction has been used widely in data mining for convenient analysis. Principal component analysis (PCA) and factor analysis (FA) methods are popular techniques. The PCA and FA reduce the number of variables to avoid the curse of dimensionality. The curse of dimensionality is to increase the computing time exponentially in proportion to the number of variables. So, many methods have been published for dimension reduction. Also, data augmentation is another approach to analyze data efficiently. Support vector machine (SVM) algorithm is a representative technique for dimension augmentation. The SVM maps original data to a feature space with high dimension to get the optimal decision plane. Both data reduction and augmentation have been used to solve diverse problems in data analysis. In this paper, we compare the strengths and weaknesses of dimension reduction and augmentation for classification and propose a classification method using data reduction for classification. We will carry out experiments for comparative studies to verify the performance of this research.