• Communications for Statistical Applications and Methods
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• v.2 no.1
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• pp.48-54
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• 1995

A direct method for fitting analysis-of-variance models to unbalanced data is presented. This method exploits sparsity and rank deficiency of the matrix and is based on Gram-Schmidt orthogonalization of a set of sparse columns of the model matrix. The computational algorithm of the sum of squares for testing estmable hyphotheses is given.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.21
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• pp.61-72
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• 1990

In the past, a fundamental technique in inventory control system was to rank the items of a inventory from a distribution by value to draw an ABC curve. Unfortunately the use of ABC categorization technique has created problems and introduced some gross errors into the inventory control system. First, the author considers the possible applications of the technique in the real world and then attempts to discuss ABC fallacies through the literatures. Finally, an inventory categorization algorithm by the principal component analysis is derived and a numerical example is also presented to illustrate the algorithm.

• Journal of the Korean housing association
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• v.16 no.6
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• pp.65-72
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• 2005

The purpose of this study is to get preeminent data from comparative analysis of multi-family housing unit plans between Korea and China nowadays. Even though Korea and China belong to common cultured band in Asia, there are many different Housing aspects and unit plans. Through this study we want to grasp the characteristics of both nation's apartment unit plans and to contribute for advance into the China apartment market. Analysis target is constructing and lotting out apartment at South Korea and China in 2004, and the space syntax model is used as an analysis tool. First, analyze kind, number and special quality of each room by use area, and second, analyze area and scale of the rooms. Through the integration analysis we know the grade of rank and centrality of each rooms, and search difference of South Korean and Chinese apartment.

• The Korean Journal of Ecology
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• v.10 no.2
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• pp.91-107
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• 1987

This study is concerned with some methods and applications, used as a basis on information and entropy analysis of vegetation data. These methods are adopted for the evaluating the effect of sampling intensity on information, which repersnets the departure of observed variable from standard component. Classes on the data matrix are caluculated by using marginal dispersion array for rank and weighting information program. Finally the information and entropy are computed by applying seven options. On the application of vegetation studies, two models for cluster analysis and analysis of concentration are explained in detail. Cluster analysis is based on use of equivocation information and Rajski's metrics. The analysis of concentration utilizes coherence coefficience being transformed values, which has been adjusted from blocks and entropy values. The relationship btween three begetation clusters and four stands of Naejangsan data is highly significant in 79% of total variance. Cluster A relatively tends to prefer north side, and cluster C south side.

• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1345-1350
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• 2003

Principal component analysis based two-dimensional (PCA-2D) correlation analysis is applied to FTIR spectra of polystyrene/methyl ethyl ketone/toluene solution mixture during the solvent evaporation. Substantial amount of artificial noise were added to the experimental data to demonstrate the practical noise-suppressing benefit of PCA-2D technique. 2D correlation analysis of the reconstructed data matrix from PCA loading vectors and scores successfully extracted only the most important features of synchronicity and asynchronicity without interference from noise or insignificant minor components. 2D correlation spectra constructed with only one principal component yield strictly synchronous response with no discernible a asynchronous features, while those involving at least two or more principal components generated meaningful asynchronous 2D correlation spectra. Deliberate manipulation of the rank of the reconstructed data matrix, by choosing the appropriate number and type of PCs, yields potentially more refined 2D correlation spectra.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.1
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• pp.100-108
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• 2004

In this paper, the new casing oscillator, which is a construction machine and which structure is similar to that of a parallel manipulator with redundancy, is proposed. The singularity analysis of this machine is performed by two different methods. First, the singularities are found by the numerical method at configurations where the rank of the Jacobian matrix becomes deficient. The singularities are outside the workspace. To investigate the physical information on these configurations, the singularities are examined by the geometric method at configurations where the casing oscillator cannot resist the external forces and moments applied to the upper platform due to losing static equilibrium. The results of the geometric method are the same as those of the numerical method. It proves that the new casing oscillator is free from the singularity, which causes serious problems to a parallel manipulator.

• Korea Journal of Hospital Management
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• v.12 no.1
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• pp.51-74
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• 2007

This study applied Data Envelopment Analysis to a set of Korean Public Corporation Medical Centers and Japanese Municipal Hospitals to compare their relative human resource efficiencies. Based on the data provided on the inputs and outputs, the analysis showed Japanese municipal hospitals were relatively efficient than Korean hospitals. The result of analysing BCC model shows 5 hospitals in Japan and 7 in Korea with an efficiency rating of less than 1 as considered relatively inefficient. For the inefficient hospitals the manner in which inefficient hospitals may be made efficient were indicated by the managerial strategies based on dual variables. A subsequent analysis of Wilcoxon rank-sum test revealed that the medical revenue per medical expense, labor cost per value added revenue were statistically significant between efficient and inefficient Korean hospitals and medical revenue per medical expense, labor cost per value added revenue, bed occupancy rate, average length of stay, rate of personnel expenses per medical revenue were statistically significant between efficient and inefficient Japanese hospitals.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.125-128
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• 1987

This paper deals with the topological observability analysis and the derivation of a reliability evaluation formula of a measurement system for state estimation. An analogy of the DC power flow method to the DC circuit analysis is introduced, and all the relationship between power flows and phase angles are replaced by the corresponding current-voltage relation. As a result, a set of topological measurement equation expressed in the form of the incidence matrix is derived for the topological analysis, and the observability test is carried out by examining the rank of the measurement matrix. The reliability evaluation formula was derived experimentally by testing the observability of sample systems of IEEE-14, IEEE-3.0, IEEE-57.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.177-186
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• 2019

The purpose of this study was to investigate the influences of the smartphone overuse on health and academic impairment in adolescents. This study used data from Korea youth risk behavior web-based survey of 2017. This survey was conducted on 64,991 adolescents(middle and high school students), and 62,276 (95.8%) responded. The researchers used frequency analysis, independent t test, chi-square test and Pearson correlation analysis using SPSS 22. As a result, the usage rate of adolescents's smartphone was 54,603 out of 62,276, which was 87.7%. The purpose of smartphone usage was messenger(1st rank, 27.3%), SNS(2nd rank, 18.7%) and game(3rd rank, 13.3%). The average daily use time of the smartphone was 206.68±194.73 minutes. Girl students showed significantly more use time of smartphones than boy students(p<.001). Students with more than 206 minutes of smartphone use had worse health and academic performance than students with less than 206 minutes(p<.001). Time of smart phone usage and academic ability showed a weak correlation(p<.001, r=.245). The present findings showed that the higher the smartphone usage, the lower the health level and academic ability, and the author discussed these results.

• Science of Emotion and Sensibility
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• v.9 no.spc3
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• pp.277-286
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• 2006

This study evaluates how much D/H and enclosed effects are closely related with each other centering around the spaces of cities in Japan. The partial ranks of the degree of angle in D/H and of the enclosure of the real spaces which the experimenter feels are measured through the method of partial rank correlation analysis on the sane objects. The result shows that all 42 samples(0.49), 25 interior space samples(0.63), and 17 exterior samples(0.59) are analysed to be less correlated. Seen above, there is limit to explaining modern spaces with the degree of angle in D/H. The result reveals that the space structure of modem cities consists of a lot more complex elements, so it is not suitable to evaluate the spaces of cities with the past theories of D/H and enclosed effect. Therefore, to evaluate the enclosed effect, a new evaluation model and a study of influential elements of city spaces and enclosed effect should be developed.