• Korean journal of food and cookery science
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• v.15 no.1
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• pp.1-7
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• 1999

The purposes of this study were to analyze the relationship between 12 independent variables and the foodservice productivity in the welfare facilities for the elderly. The results of the study were summarized as follows; 1. 67.2 percentage of surveyed welfare facilities for the elderly were not managed by dietitians, so menu planning, food purchasing, management of eqipment and facilities, sanitary practice, and management of work were administered nonsystematically. 2. From the results of factor analysis of variables related to the affecting productivity, 5 factors were generated and the factors were named ‘foodservice scale’, ‘human resourcs’, ‘use of food’, ‘use of equipment’ and ‘use of document’, and then the relation between the factor variables and productivity was examined by multiple regression anlysis.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.555-558
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• 1991

The IESF(Integral Error and State Feedback) controller, which incorporates state feedback as a modern control scheme and integral action as a classical control scheme, has better performance than that of the conventional PID controller in linear time-invariant systems. The IESF controller requires the measurement of all the state variables. But, unfortunately, it may be difficult or impossible to measure all state variables in many applications. And the IESF controller is applicable only to pole-assignable linear time-invariant system without time delay. In this paper, new IESF controller structure was proposed which performs feedback with only measurable state variables. In order to estimate the unmeasurable state variables. It was adopted the filter mode by full-order obserber. The good performance and effectiveness of the proposed controller was confirmed by computer simulation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.487-493
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• 2004

This paper consider a six sigma project for improving the TIP life time in a spot welding process. The project follows a disciplined process of five phases: define, measure, analyze, improve, and control. A process map is used to identify process input and output variables. Nine key process input variables are selected by using C&E matrix and FMEA, and finally four vital few input variables are selected from analyze phase. The optimum process conditions of the four vital few input variables are jointly obtained by maximizing TIP life time using DOE.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.185-197
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• 1998

Engineering design involves the specification of many variables that define a product, how it is made, and how it behaves. Before some variables can be determined, other variables must first be known or assumed. This fact implies a precedence order of the variables, and of the tasks of determining these variable consequently. Moreover, design of complex systems may involve a large number of design activities. In this paper, the activity-activity incidence matrix is considered as a representation of design activity analysis which mainly focuses on the precedence constraint. In order to analyze the activity-activity incidence matrix, a heuristic algorithm is proposed, which transforms an activity-activity, parameter-formula, and parameter-parameter incidence matrix into a lower triangular form. The analysis of the structured matrices can not only significantly reduce the overall project complexity by reorganizing few critical tasks in practice, but also aims at obtaining shorter times considering the solution structure by exploring concurrency.

• Korean Journal of Child Studies
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• v.22 no.1
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• pp.135-146
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• 2001

The present study investigated socio-organizational variables which influence teachers' commitment to the organization. Subjects were 254 teachers of private kindergartens in Kimhae, Kyungnam-do, and Tongrae-gu and Kangseo-gu in Pusan. The instrument was a questionnaire developed by Rosenholtz(1991), originally developed for the study of the teachers' work place (the social organization of elementary schools) and revised here for Korean early education. The data were analyzed by ANCOVA. Results revealed that the most important variable influencing teachers' organizational commitment is teachers' job certainty, next is teachers' learning opportunities; other variables are teachers' career, psychological rewards, and task autonomy and discretion.

• Korean Journal of Child Studies
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• v.11 no.2
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• pp.59-81
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• 1990

The purpose of this study was to investigate family-demographic variables (sibling status, maternal attitude and demographic variables) affecting sibling sociability and peer sociability. Mothers and teachers of 291 kindergarten children were sampled. Specifically, 206 children of two-child families were studied by sibling status to investigate differences in sociability among siblings. Factor analysis, F-test, Pearson correlation, and multiple-analysis of variance were conducted. Sibling sociability and peer sociability were affected by sibling status. Maternal attitude and sibling sociability were positively correlated. The important family-demographic variables for both sibling sociability and peer sociability were maternal affective attitudes and sex of child.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.50.1-50
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• 2001

Dynamic optimization with partially structured model in a slurry-phase HDPE reactor is implemented by the modified hierarchical dynamic optimization. Optimal trajectories of MI and density of HDPE are calculated as controlled variables and optimal profiles of the concentrations of ethylene, hydrogen and comonomer are calculated as manipulated variables in dynamic optimization. MI, density, the concentrations of ethylene, hydrogen and comonomer are used as controlled variables and flow rates of ethylene, hydrogen and comonomer are sued as manipulated variables in control implementation. Two-level hierarchical method is applied in dynamic optimization to reduce computation time. In the upper level formulation ...

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.58.1-58.1
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• 2012

We present a comprehensive re-analysis of stellar photometric variability in the field of open cluster M37, using our new high-precision light curves. This dataset provides a rare opportunity to explore different types of variability between short (-minutes) and long (-one month) time-scales. To investigate the variability properties of -30,000 objects, we developed new algorithms for detecting periodic, aperiodic, and sporadic variability in their light curves. About 7.5% (2,284) of the total sample exhibits convincing variations that are induced by flares, pulsations, eclipses, starspots and, in some cases, unknown causes. The benefits of our new photometry and analysis package are evident. The discovery rate of new variables is increased by 63% in comparison with the existing catalog of variables, and 51 previously identified variables were found to be false positives resulting from time-dependent systematic effects. Based on extended and improved catalog of variables, we will review the basic properties (e.g., periodicity, amplitude, type) of the variability and how different they are for different spectral types and for cluster memberships.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.6
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• pp.1014-1019
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• 2003

A dynamic modeling method for beams undergoing overall rigid body motion is presented in this paper. Two special deformation variables are introduced to represent the stretching and the curvature and are approximated by the assumed mode method. Geometric constraint equations that relate the two special deformation variables and the cartesian deformation variables are incorporated into the modeling method. By using the special deformation variables, all natural as well as geometric boundary conditions can be satisfied. It is shown that the geometric nonlinear effects of stretching and curvature play important roles to accurately predict the dynamic response when overall rigid body motion is involved.

• Journal of the Korean Home Economics Association
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• v.38 no.11
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• pp.115-126
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• 2000

This study investigated the relationship of demographic and psychological variables with job and family-related stress among 293 employed wives. We found that age, job types, working in weekend, and family cohesion significantly contributed to the explanation of job-related stress. We also found that job types, working in weekend, family adaptation, family cohesion, and employment motivation significantly contributed to explaining the variation of family-related stress. Job-related stress was more explained by demographic variables than psychological ones, whereas family-related stress was more explained by psychological variables than demographic ones. Practical implications of the current findings were discussed.