• Management Science and Financial Engineering
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• v.4 no.2
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• pp.1-13
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• 1998

The Shortest Path Problem in Time-dependent Networks, where the travel time of each link depends on the time interval, is not realistic since the model and its solution violate the Non-passing Property (NPP:often referred to as FIFO) of real phenomena. Furthermore, solving the problem needs much more computational and memory complexity than the general shortest path problem. A new model for Time-dependent Networks where the flow speeds of each link depend on time interval, is suggested. The model is more realistic since its solution maintains the NPP. Solving the problem needs just a little more computational complexity, and the same memory complexity, as the general shortest path problem. A solution algorithm modified from Dijkstra's label setting algorithm is presented. We extend this model to the problem of Minimum Expected Time Path in Time-dependent Stochastic Networks where flow speeds of each link change statistically on each time interval. A solution method using the Kth-shortest Path algorithm is presented.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.71-80
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• 2018

The path and visibility of nurses in general hospital wards have been treated as architectural planning factors. However, the analysis approach of existing studies shows limitations that only fixed physical elements are considered without considering the behavior of users using space. Consider factors for analysis of ward and models based on this study model. Select a case hospital to apply the analysis technique and conduct the nurse questionnaire and route survey of the hospital. Establish a framework for analysis model applied with the path of nurse movements. The analysis model applies to the case hospital. The analysis results are aggregated to derive design suggestion for reference to the spatial improvement of the ward. Visible visibility to observe the bedside in the nursing station, visibility to observe the beds in the nurse's path, and visibility to observe patients moving in the nurse's path were derived from visual access frequency and exposure frequency. The survey of nurses' movements at the site allowed the nurses to calculate the distance required to move. Reflecting the path of nurse movement, a model was presented for a comprehensive analysis of nursing distance and nursing visibility, which could lead to improvement in the observation and visibility of nurses and the layout of patient rooms or day rooms.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1111-1117
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• 2003

NURBS (Non Uniform Rational B-Spline) is widely used in CAD system and NC data for high speed machining. Conventional CAM system changes NURBS surface to tessellated meshes or Z-map model, and produces linear tool path. The linear tool path is not good for precise machining and high speed machining. In this paper, an algorithm to change linear tool path to NURBS one was studied, and the machining result of NURBS tool path was compared with that of linear tool path. The N-post, post-processing and virtual machining software was developed. The N-Post post-processes linear tool path to NURBS tool path and quickly shades machined product on OpenGL view and compares a machined product with original CAD surface. A virtual machined model of original tool path and post-processed tool path was compared to original CAD model. The machining error of post-processed NURBS tool path was reduced to 43%. The original tool path and NURBS tool path was used to machine general model using same machine tool and machining condition. The machining time of post-processed NURBS tool path was reduced up to 38%.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.773-782
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• 2014

The general path model (GPM) is one approach for performing degradation-based, or Type III, prognostics. The GPM fits a parametric function to the collected observations of a prognostic parameter and extrapolates the fit to a failure threshold. This approach has been successfully applied to a variety of systems when a sufficient number of prognostic parameter observations are available. However, the parametric fit can suffer significantly when few data are available or the data are very noisy. In these instances, it is beneficial to include additional information to influence the fit to conform to a prior belief about the evolution of system degradation. Bayesian statistical approaches have been proposed to include prior information in the form of distributions of expected model parameters. This requires a number of run-to-failure cases with tracked prognostic parameters; these data may not be readily available for many systems. Reliability information and stressor-based (Type I and Type II, respectively) prognostic estimates can provide the necessary prior belief for the GPM. This article presents the Bayesian updating framework to include prior information in the GPM and compares the efficacy of including different information sources on two data sets.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.4
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• pp.199-206
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• 2018

In this study, numerical analysis is applied to a two - dimensional model for verifying the general finite element program, Abaqus' s extended finite element method(XFEM). The cohesive element model used in the existing research has a limitation in simulating the actual crack because of the disadvantage that the crack path should be predicted and the element should be inserted. For this reason, the extended finite element method(XFEM), which predicts the path of cracks based on the directionality and specificity of stress, is emerging as a new solution in crack analysis. The validity of the XFEM application was confirmed by comparing the cohesive element analysis with the XFEM analysis by applying the crack path to the self - evident two - dimensional model. Numerical analysis confirms stress distribution and stress specificity immediately before crack initiation and compares it with actual crack initiation path. Based on this study, it is expected that cracks can be simulated by performing actual crack propagation analysis of complex models.

• The Korean Journal of Rehabilitation Nursing
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• v.15 no.1
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• pp.20-29
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• 2012

Purpose: The purpose of this study was to explore factors affecting uncertainty and general well-being based on Uncertainty in Illness Theory. Methods: Data were collected from 125 outpatients who had received hemodialysis. The path model among four concepts, such as period of hemodialysis, social support, uncertainty, and general well-being, was tested. Tangible support, positive social interaction, affectionate, and emotional/informational support were measured as social support. Adaptation in the model was operationalized as general well-being which consisted of anxiety, depression, positive well-being, self-control, and general health. Results: All paths were statistically significant at the level of ${\alpha}$=.05. The significant paths were the path from period of hemodialysis to uncertainty (t=-2.86), social support to uncertainty (t=-2.01), uncertainty to general wellbeing (t=-2.85), and social support to general well-being (t=3.55). Conclusion: Patients who perceived low uncertainty and high social support were likely to feel well-being. Therefore, nurses should give patients appropriate information according to their needs and have meaningful interaction with patients to reduce their uncertainty and render social support.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.939-951
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• 1996

The previous study of virtual path design for one traffic class with ATM DCS only should be generalized to that for the multiple traffic class cases of being given neither virtual path candidate set nor end nodes o each virtual path. In this paper, a design model of virtual paths for the general case with multiple traffic classes is suggested. The model is represented as an optimization rpoblem with a special structure. It is solved by SQA algorithm, which is developed by authors in [3, 4]. The model and the algorithm are applied to a numerical example, and results are shown.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.6
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• pp.122-127
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• 1996

The achievement of the optimal condition for the task of an industrial articulated robot used in many fields is an important problem to improve productivity. In this paper, a minimum-time trajectory for an articulated robot along the specified path is studied and simulated with a proper example. A general dynamic model of manipulator is represented as a function of path distance. Using this model, the velocity is produced as fast as possible at each point along the path. This minimum-time trajectory planning module together with the existing collision-free path planning modules is utilized to design the optimal path planning of robot in cases where obstacles present.

• Journal of Global Scholars of Marketing Science
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• v.17 no.1
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• pp.23-49
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• 2007

The purpose of this study is to investigate the relationships among customer satisfaction, trust, and loyalty and examine the differences and similarities between specialized and general merchandise internet shopping malls concerning the relationships of these key success factors. The structural model is tested with each of the sub-samples(i.e., specialized and general merchandise shopping customers taken separately) and the data from entire data samples(i.e., specialized and general merchandise shopping customers pooled together). The same research model was used in analysing general merchandise, specialized, and integrated internet shopping mall to reveal and compare the casual path constructs. In the analysis of path coefficients composed of separated taken sample, all research hypothesis is accepted and the model's goodness of fit also shows all high. In the basis of the previous empirical test, multiple sample method was used. Properties of the causal paths, including standardized path coefficients, the significance of difference, latent correlations and variance explained for satisfaction, trust and loyalty in the hypothesized model, have similarities in general. This means that the proper structural management concerned with customer satisfaction, trust and loyalty is very crucial for the success of all kinds of internet shopping malls. Following the model test, I conduct a test of integrated model's path coefficients. Statistical results show that all the hypothesis concerned with internet shopping malls were accepted like the separated sample test. Click and mortar companies should clearly understand and articulate the key requirements of shopping mall satisfaction, trust and loyalty and encourage to establish linkage and interactive relationship among the research variables. In addition, internet marketers are required to customize the interaction considering and adapting the patterns of internet shopping malls. Other interesting results concerning the strategies in internet shopping malls strategy are also presented.

• Journal of Korean Academy of Nursing Administration
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• v.11 no.4
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• pp.371-384
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• 2005

Purpose: The aim of this study was to analysis path model of the research variables. Methods: The subjects of this study were 647 nurses who were working in the 8 general hospitals located in Seoul and Incheon area. The data were collected by self-reporting questionnaires. The data were analyzed using descriptive statistics and path analysis. Results: In the modified path model, overall fitness indexes were $X^2$= 223.27, goodness of fit index=0.90, root mean square residual=0.039, root mean square error of approximation=0.12, non-normed fit index=0.96, and normed fit index=0.90. From the model, among research variables that influence organizational effectiveness motivator, job satisfaction and organizational identification affected directly work performance. In internal marketing factors, paid-leave, communication and reward affected directly motivator. Motivator and hygiene factors affected directly job satisfaction, organizational commitment and organizational identification. Conclusion: With these findings, paid-leave, communication, reward, motivator, job satisfaction and organizational identification were direct or indirect predictors of the work performance. Therefore nursing managers ought to develop internal marketing strategies and motivation enhancing system for nurses based on this path model in order to improve the nursing organizational effectiveness.