• Journal of Bone Metabolism
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• v.25 no.4
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• pp.251-266
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• 2018

Background: The causal networks among genes that are commonly expressed in osteoblasts and during bone metastasis (BM) of breast cancer (BC) are not well understood. Here, we developed a machine learning method to obtain a plausible causal network of genes that are commonly expressed during BM and in osteoblasts in BC. Methods: We selected BC genes that are commonly expressed during BM and in osteoblasts from the Gene Expression Omnibus database. Bayesian Network Inference with Java Objects (Banjo) was used to obtain the Bayesian network. Genes registered as BC related genes were included as candidate genes in the implementation of Banjo. Next, we obtained the Bayesian structure and assessed the prediction rate for BM, conditional independence among nodes, and causality among nodes. Furthermore, we reported the maximum relative risks (RRs) of combined gene expression of the genes in the model. Results: We mechanistically identified 33 significantly related and plausibly involved genes in the development of BC BM. Further model evaluations showed that 16 genes were enough for a model to be statistically significant in terms of maximum likelihood of the causal Bayesian networks (CBNs) and for correct prediction of BM of BC. Maximum RRs of combined gene expression patterns showed that the expression levels of UBIAD1, HEBP1, BTNL8, TSPO, PSAT1, and ZFP36L2 significantly affected development of BM from BC. Conclusions: The CBN structure can be used as a reasonable inference network for accurately predicting BM in BC.

• ETRI Journal
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• v.25 no.5
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• pp.345-355
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• 2003

In this paper, we propose a method for designing a class of M-channel, causal, stable, perfect reconstruction, infinite impulse response (IIR), and parallel uniform discrete Fourier transform (DFT) filter banks. It is based on a previously proposed structure by Martinez et al. [1] for IIR digital filter design for sampling rate reduction. The proposed filter bank has a modular structure and is therefore very well suited for VLSI implementation. Moreover, the current structure is more efficient in terms of computational complexity than the most general IIR DFT filter bank, and this results in a reduced computational complexity by more than 50% in both the critically sampled and oversampled cases. In the polyphase oversampled DFT filter bank case, we get flexible stop-band attenuation, which is also taken care of in the proposed algorithm.

• Korean System Dynamics Review
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• v.12 no.4
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• pp.35-62
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• 2011

PFI(Private Finance Initiative) for suppling SOC and public facilities instead of Government Infrastructure Project introduced from 1994. BTO(Build-Transfer-Operate) project had been major type of PFI system from 1994 to 2005. But after changed the Law of PFI on SOC, the BTL project newly introduced. In BTO system, the Government retrieves the investment through the operating income, but in BTL system, the government lease the facilities. As the BTO and BTL projects are widely adopted and implemented to ease the fiscal burden of government, but it has caused the tremendous fiscal burden each year over the period operation. Therefore this study attempted to analyze the question, that is, why government fiscal burden tipping? Hence, this paper, compares the difference of business structure between BTO and BTL project and explore the vicious and virtuous business structure, with the method of circular causal loop analysis. As a result, it has shown that there are some positive feedback and negative feedback loops cause the tipping and easing of government fiscal burden.

• Health Policy and Management
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• v.21 no.2
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• pp.263-278
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• 2011

As the competition among hospitals become intensified, hospital management is required to carry out more effective marketing and positioning of the hospital. Successful positioning of a hospital requires the knowledge about how the concrete attributes inherent in the medical service associated with the customer values that customers seek eventually in the medical service. Thus, it is required for hospital management to understand which hospital attributes should be emphasized in order to improve the customer values. The hierarchical structure of service attributes can provide valuable information about effective positioning and advertising. To obtain such knowledge, we employed the order analysis technique as an objective means-end chain method. Order analysis is useful for identifying the causal structure among attributes. Thus, we can examine the underlying causal relationship and eventually the vertical structure of hospital selection attributes. For this study, we conducted a survey to obtain 370 responses for the analysis. The result suggests that hospital management had better increase the scale of hospital, improve the services of health care providers, and modernize the hospital facilities and equipments so as to enhance customer values and eventually to lead them to recommend the hospital to others. Our findings would provide the valuable information for hospital management to develop the more effective hospital positioning and marketing strategies.

• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.50-59
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• 2021

The main purpose of accident analysis is to identify the causal factors and the mechanisms of those factors leading to the accident. However, current accident analysis techniques focus only on finding the factors related to the accident without providing more insightful results, such as structures or mechanisms. For this reason, preventive actions for safety management are concentrated on the elimination of causal factors rather than blocking the connection or chain of accident processes. This greatly reduces the effectiveness of safety management in practice. In the present study, a technique to model the correlational structure of accident risk factors is proposed by using the co-occurrence keyword network analysis technique. To investigate the effectiveness of the proposed technique, a case study involving a portable ladder fall accident is conducted. The results indicate that the proposed technique can construct the correlational structure model of the risk factors of a portable ladder fall accident. This proves the effectiveness of the proposed technique in modeling the correlational structure of accident risk factors.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.4
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• pp.50-60
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• 1996

The purpose of this study is to investigate the prime factors that affect user satisfaction of area and facilities in urban forests, to classify those factors, to find out factorial structure of user satisfaction about them, and then to suggest important indicators in the urban forest planning, design, and development. The survey research was done using the self-administered questionnaire method by the people in the city of the Pusan who participated in recreational activities in the Mt. Keumjung. Factor analysis was used to extract the prime factors related to the recreational satisfaction concerning the area and facilities of the urban forest by the SPSS program, and then prime factors were used to investigate the factorial structure of user recreational satisfaction in the urban forest by the LInear Structure RELation program. According to the factor analysis concerning the 13 variables, 4 prime factors by the statistical values were considered as effective, indicating, 'health and recreational facilities', 'convenience and management facilities','facilities for the physical and psychological training' and 'historical and cultural areas'. The results of the causal structure analysis were identified as having significant effects mutually on endogenous variables, 'overall recreational satisfaction of the areas and facilities in the Mt. Keumjung','health and recreational facilities','convenience and management facilities','facilities for the psychological training', and 'historical and cultural areas'. But exogenous variables which have significant effects on endogenous variables were also indentified. Overall fits of both causal model were very good. The hypothetical causal structural equation models based on the results found partially significant correlation between dndogenous variables and between envogenous and exogenous variables. These significant relationships indiate important factors and variables that should be considered in planning, design, and development of the urban forests. Therefore, development direction of the Mt. Keumjung has to be analyzed as significant factors concerning user recreational satisfaction in a systematic was, recognized as important variables for planning process. The plan for development and management also should reflect the natural conservation policy from the environmental conservation movement like natural conservation advertisement and environmental education.

• Asia pacific journal of information systems
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• v.7 no.2
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• pp.225-266
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• 1997

A Causal Transition Model of the IT impact on organization is proposed. The model is based upon the premise that the IT impact is a multi-phase, multi-realm phenomenon, and that the IT impact in one organizational realm logically transpires to another realm, thus forming complex causal webs among them. Two exploratory research studies, the one qualitative and the other quantitative, were conductea to validate the model in a setting involving major structural reorganization of the organizations' IT function. The research results provide support for the general theory structure of the model. The findings include: ⅰ) the IT impact manifests on multiple organizational realms, with different degrees of strength, ⅱ) the impact on the realms follow a particular causal transition path among them, and ⅲ) the IT impact manifests on and through the information processing aspect of work. The results, however, indicate that people's perception of the IT impact is strongly mitigated by the IT relevance of work, and that the organization is affected as much by the structural arrangement surrounding and accompanying the IT as by the technology itself, suggesting that the IT impact is an organizational phenomenon as well as a technological phenomenon. The implications of the research results are discussed at the end.

• Korean System Dynamics Review
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• v.11 no.2
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• pp.5-28
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• 2010

The purpose of this paper is to review relationship between spatial characteristics of compact city and urban sustainabiliy from system dynamics perspective using causal loop analysis. It has been argued that spatial characteristics of compact city, high population density and mixed land use, are positively related to urban sustainability. However, research results that are not consistent with pros of compact city argument have been accumulated too. It is especially true when spatial characteristics of compact city are examined with regard to each dimension of sustainablility: economic, social, and environmental sustainability. Reviewing each dimension of sustainability with regard to spatial characteristics based on causal loop analysis, this paper provides more clear understanding on relationship between compact city and sustainability. Also this paper provides a base for system dynamics simulation for future study.

• Journal of Korean Society for Quality Management
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• v.38 no.3
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• pp.378-390
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• 2010

From the perspective of employees working for public service agencies, we analyzed the causal relationship between service quality, relationship quality, design quality, customer satisfaction, and trust in public services. We conduct statistical analyses on the quality attributes we derived from a critical incident technique(CIT) analysis and build a measurement model, which has a second-order hierarchical structure. Survey data was collected from social work, childcare, and healthcare services. Using a structural equation modeling method, we identify a causal model and simultaneously estimate factor loadings and path coefficients. We find that all the quality dimensions are antecedents to satisfaction and then satisfaction precedes trust. The results show that service quality and design quality mediate in parallel the effect of relationship quality on satisfaction and both relationship and design qualities have stronger effects on satisfaction rather than service quality.

• Korean Journal of Adult Nursing
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• v.18 no.1
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• pp.115-124
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• 2006

Purpose: The purpose of this study was to propose a theoretical model of hope commonly held by the cancer patients just after surgery, under the assumptions that hope of those patients is not only realistic and disease oriented but in dialectical circulation. Method: A theoretical model was generated through 4 steps: exploring a hope structure by synthesizing the relevant hope structures expressed in Kim and Tae's studies, in-depth literature review, examining the meanings of the concepts consisted of the structure in use and their causal relations in logical adequacy, proposing a theoretical structure through synthesizing the causal relations, and diagramming the structure. Results: The proposed theoretical model involves concepts such as Cancer Related Uncertainty (CRU), Efforts to Find out the Possibility of Cure or Recovery (EFPCR), and Hopefulness or Hopelessness. The 'EFPCR' is stipulated as 'Behaviors Related to Looking for Evidences or Cues (BRLEC)' and 'Formation of Cognitive Schema (FCS)'. In the model, Hopefulness is directly influenced by 'CRU in low', which is affected by 'FCS in good' from the result of EFPCR started with 'CRU in increase' while 'CRU with increase' from the result from EFPCR has direct effect on Hopelessness. Conclusion: The theoretical model would be used to enhancing hope of the cancer patients in post-operation.