• The Journal of Korean Academic Society of Nursing Education
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• v.14 no.2
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• pp.224-231
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• 2008

Purpose: The purpose of this study was to analyze the types of the causal perception of preterm labor. Method: The research design was a Q-Methodological Approach. Thirty four selected Q-statements from 32 participants were classified into a shape of normal distribution using a 9 point scale. The collected data was analyzed using a QUANL PC program. Result: Three types of causal perception for research subjects were identified. Type I is negligence of causality; Type II is recognition of causality by preceding factors. Type III is recognition of causality by psychological stress. Conclusion: This study found that there are differences in perceiving causes of preterm labor. Therefore, it is necessary to develop a tailored nursing intervention depending on these types.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.210-218
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• 2007

Road freight transport industry in Korea contains many and complicate problems such as over supply of the vehicle caused by rapid policy changes, illegal multilevel transactions, poor truck drivers working environment, lack of road freight transport related statistics and so on. Korean government has developed various logistics industrial policy trying to solve these problems in various ways. However, the relationship among the problems and action plans has been more and more entangled since the part of suggested policies have made another perverted problems. These complex structure of the toad freight transport industry in Korea makes difficult to identify and to solve the problems. Causal map method helps to give a clean picture to understand the complex industry at a glance. This study contributes for visualization of the causal relationships among the existing problems and related policy issues in the road freight transport industry in Korea by causal map. This study could be helpful to develop the actual road freight transport industrial policies including the illogical multilevel and unfair transaction in Korea.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.1
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• pp.17-40
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• 1994

The objectives of this paper are to apply fuzzy cognitive map (FCM)- related techniques to (1) extract causal knowledge from a specific problem-domain and (2) perform a series of causal analysis in complicated decision making area. We propose a set operation-based augmentation (SOBA) algorithm to combine multiple FCMs developed by multiple experts. Based on the SOBA knowledge acquisition algorithm, we can obtain a causal knowledge base fairly representing multiple experts' knowledge about a problem domain. The causal knowledge base built by SOBA algorithm can be described as a matrix form, guaranteeing mathematically compact operation compared with a production (if-then) knowledge base. We applied out method to stock market analysis problem whichis a typical of highly unstructured problems in OR/MS fields.

• Communications for Statistical Applications and Methods
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• v.31 no.1
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• pp.155-178
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• 2024

Regression discontinuity (RD) design is one of the most widely used methods in causal inference for estimation of treatment effect when the treatment is created by a cutpoint from the covariate of interest. There has been little attention to RD design, although it provides a very useful tool for analysis of treatment effect for censored data. In this paper, we define the causal effect for survival function in RD design when the treatment is assigned deterministically by the covariate of interest. We propose estimators of this causal effect for survival data by using transformation, which leads unbiased estimator of the survival function with local linear regression. Simulation studies show the validity of our approach. We also illustrate our proposed method using the prostate, lung, colorectal and ovarian (PLCO) dataset.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.267-272
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• 2007

In the construction industry government is not only an owner but also a consumer. Accordingly it should develop the construction industry and this role is important. Among them, the law of the ordering method is standards of selecting a successful bidder and have powerful influence over the construction industry and owners. Therefore this study said how the lowest bid method, which has taken effect still more, has influence on the construction industry and the public sector with the Causal Loop Diagram. According to analyzing this construction law, we can grasp the point of the strength and weakness of this law also examine a trend of how the present law is changed. While we studied, we tried to adhere to neutrality and form a new opinion about it because the previous studies were opposed to each other. As a result, to improve the relation between the government and private company, which were opposed to each other about arguments for and against the lowest bid method, this study suggest the method of making better the relation. The final goal of it is researching the inefficient factors and improving the weakness of this law.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.5
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• pp.450-457
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• 2004

In this research, the automatic synthesis of knowledge models is proposed. which are the basis of the methods using qualitative models adapted widely in fault diagnosis and hazard evaluation of chemical processes. To provide an easy and fast way to construct accurate causal model of the target process, the Role-Behavior modeling method is developed to represent the knowledge of modularized process units. In this modeling method, Fault-Behavior model and Structure-Role model present the relationship of the internal behaviors and faults in the process units and the relationship between process units respectively. Through the multiple modeling techniques, the knowledge is separated into what is independent of process and dependent on process to provide the extensibility and portability in model building, and possibility in the automatic synthesis. By taking advantage of the Role-Behavior Model, an algorithm is proposed to synthesize the plant-wide causal model, Fault-Causality Graph (FCG) from specific Fault-Behavior models of the each unit process, which are derived from generic Fault-Behavior models and Structure-Role model. To validate the proposed modeling method and algorithm, a system for building FCG model is developed on G2, an expert system development tool. Case study such as CSTR with recycle using the developed system showed that the proposed method and algorithm were remarkably effective in synthesizing the causal knowledge models for diagnosis of chemical processes.

• Korean Business Review
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• v.20 no.2
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• pp.119-133
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• 2007

The present study purposed to examine whether BSC, a management renovation method, is as effective in university hospitals, which are non-profit institutions, as it is in profit-making corporations. In order to determine causal relations among the BSC performance measurement indexes, we analyzed a case of university hospital using a structural equation model. The results of analyzing the causal relations among the BSC performance measurement indexes were all statistically significant, and therefore the research hypotheses were all accepted. Future research needs to study causal relations among the BSC performance measurement indexes from the viewpoint of the learning of financial data, growth, internal processes, and customers.

• Journal of Korean Clinical Nursing Research
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• v.14 no.3
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• pp.61-72
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• 2008

Purpose: The purpose was to identify quality of chest pain according to causal diseases and pain expression of patients with coronary artery diseases. Method: Participants were 1,964 patients with pain who visited the emergency department of A hospital from January to December 2006. Data were collected from nurses' and doctors' records as to causal disease, and quality and expression of chest pain. Results: Causal diseases were coronary artery diseases, non-specific chest pain, respiratory diseases, non-coronary artery heart diseases and digestive diseases in that order of frequency. Every disease except respiratory disease caused mostly dull and tract pain, but 63.7% of patients with coronary artery diseases complained of typical angina pain and 24.9% complained of atypical angina pain. Patients with coronary artery diseases mostly used word 'heaviness' in describing their dull pain, and 'squeezing' for tract pain. Both male and female patients who were diagnosed with coronary artery disease complained mostly frequently of dull pain and tract pain. Conclusion: The most common causal disease for patients with chest pain was coronary artery disease. Patients with other diseases also frequently complained of dull and tract pain, the same as patients with coronary artery diseases. A considerable number of patients complained various types of atypical angina pain in coronary artery diseases.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.3 s.39
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• pp.143-154
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• 1990

This study aims at identifying factors and variables which have significant effects on users satisfaction with recreational activities and facilities in Apsan city natural park and therby establishing indicies of planning and / or development of urban forest. To test the causal models of this research, The data were gathered by self-administered questionnaires from 1,147 households in Taegu city which were selected by the multi-stage probabiling sampling method. The analysis of the data primarily consist of two phases : The first analysis dealt with exploratory factor analysis which identified major factors involved in satisfaction with recreational activities and facilities in Apasn city natural park and the second analysis tested the fit of causal models of this research to the data using LISREL methodology. The factor analysis identified that three significant factors are involved in satisfaction with recreational activities and five significant factors are inherent in satisfaction with recreational facilities. The second phase analysis tested the fit of the causal models for satisfaction with recreational activities and facilities to the data and identified statistically significant causal linkage among overall satisfaction with the park, other indogenous factors and exogenous variables. These significant relationships represent important factors and variables that should be considered in planning and/of development of the city natural park. On the basis of there significant causal relationships implications for planning and/or development of the city natural park were suggested.

• Structural Engineering and Mechanics
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• v.23 no.4
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• pp.409-430
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• 2006

The aim of this study is to investigate the reliability of strong motion records processed by causal and acausal Butterworth filters in comparison to the results obtained from a synthetic accelerogram. For this purpose, the fault parallel component of the Bolu record of the Duzce earthquake is modeled with a sum of exponentially damped sinusoidal components. Noise-free velocities and displacements are then obtained by analytically integrating the synthetic acceleration model. The analytical velocity and displacement signals are used as a standard with which to judge the validity of the signals obtained by filtering with causal and acausal filters and numerically integrating the acceleration model. The results show that the acausal filters are clearly preferable to the causal filters due to the fact that the response spectra obtained from the acausal filters match the spectra obtained from the simulated accelerogram better than that obtained by causal filters. The response spectra are independent from the order of the filters and from the method of integration (whether analytical integration after a spline fit to the synthetic accelerogram or the trapezoidal rule). The response spectra are sensitive to the chosen corner frequency of both the causal and the acausal filters and also to the inclusion of the pads. Accurate prediction of the static residual displacement (SRD) is very important for structures traversing faults in the near-fault regions. The greatest adverse effect of the high pass filters is their removal of the SRD. However, the noise-free displacements obtained by double integrating the synthetic accelerogram analytically preserve the SRD. It is thus apparent that conventional high pass filters should not be used for processing near-fault strong-motion records although they can be reliably used for far-fault records if applied acausally. The ground motion parameters such as ARIAS intensity, HUSID plots, Housner spectral intensity and the duration of strong-motion are found to be insensitive to the causality of filters.