• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.593-601
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• 1999

The knowledge about structure of the velocity in the stream IS essential in the investigation of stream meandering, erosion and sediment transport, and dispersion of pollutants in the stream. In this study, theoretical velocity profile model in which transverse profile of the longitudinal velocity in the stream can be predicted using stream hydraulic data was developed. The proposed model was tested with the measured velocity data of the Nakdong river. The result shows that the numerical model simulates properly the general shalxc of the measured velocity profiles. The simulated profiles agree well with measurements, especially in the aspects of skewness and flatness.atness.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.467-470
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• 2004

MANPro-based control is a novel control paradigm aimed at intelligent manufacturing systems on the basis of mobile agent-based negotiation process (MANPro). MANPro is a negotiation mechanism based on the agent-based control architecture and, especially, it adapts a mobile agent system called N-agent for the negotiation process. N-agent travels around the network of distributed manufacturing systems to acquire information, and it makes a decision for system control according to the obtained information. MANPro includes communication architecture and information architecture for intelligent shop floor control. MANPro also considers the following issues: (1) negotiation mechanism, (2) single-agent internal strategic policies, and (3) information model. Communication architecture concerns the first issue of the negotiation mechanism. It provides information exchanging mechanism with functional modules. In specific, N-agent is equipped with an intelligent reasoning engine with a built-in knowledge base. This reasoning engine is closely related to the single-agent internal strategic policies of the second issue. Finally, ontology-based information architecture addresses information models and provides a framework for information modeling on negotiation. In this paper, these three issues are addressed in detail and a framework of MANPro-based control is also proposed.

• Industrial Engineering and Management Systems
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• v.16 no.1
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• pp.64-79
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• 2017

Identifying disease genes from human genome is a critical task in biomedical research. Important biological features to distinguish the disease genes from the non-disease genes have been mainly selected based on traditional feature selection approaches. However, the traditional feature selection approaches unnecessarily consider many unimportant biological features. As a result, although some of the existing classification techniques have been applied to disease gene identification, the prediction performance was not satisfactory. A small set of the most important biological features can enhance the accuracy of disease gene identification, as well as provide potentially useful knowledge for biologists or clinicians, who can further investigate the selected biological features as well as the potential disease genes. In this paper, we propose a new stepwise random forests (SRF) approach for biological feature selection and disease gene identification. The SRF approach consists of two stages. In the first stage, only important biological features are iteratively selected in a forward selection manner based on one-dimensional random forest regression, where the updated residual vector is considered as the current response vector. We can then determine a small set of important biological features. In the second stage, random forests classification with regard to the selected biological features is applied to identify disease genes. Our extensive experiments show that the proposed SRF approach outperforms the existing feature selection and classification techniques in terms of biological feature selection and disease gene identification.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.1
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• pp.102-111
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• 2014

An analytical model was developed to understand the physics and predict the functional performance of a pin puller. The formulated model is based on one-dimensional gas dynamics for an ideal gas. Resistive forces against pin shaft movement were measured in quasi-static mechanical tests, the results of which were incorporated into the model. The expansion chamber pressure and the pin shaft displacement were measured from an actual firing test and compared to the model prediction. The gas generation rate was adjusted by a correction factor, and the heat transfer rate was obtained through parametric analysis. The validity of the model is assessed for additional firing tests with different amounts of pyrotechnic charge. This model can provide knowledge on how the pin puller functions, and on which design parameters contribute the most to the actuation of the pin puller. Using this model, we estimate the functional safety factor by comparing the energy generated by the pyrotechnic charge to the energy required to accomplish the function.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.27-42
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• 2009

The research aims to identify factors affecting the use of government export marketing assistance programs and future improvements of the programs. 500 Korean exporting firms were used as a sample and research hypotheses were tested by the structural equation modeling using AMOS 7.0. The empirical findings are as follows. First, exporting firms' awareness of export marketing assistance programs showed a positive impact on their use of the programs. Second, small exporters showed higher awareness and use of the programs than large ones. Third, the firms with low export intensity showed higher awareness and use of the programs than those with high export intensity. Fourth, exporters having high orientations for overseas market showed higher awareness and use of the programs than those with low international orientations. Fifth, exporters having high proportion of direct exports showed higher awareness and use of the programs than those with low proportion of direct exports. Also, the effects of these firm-specific characteristics on the use of the programs were found to be done indirectly, in other words, through the awareness of the programs. Therefore, it was concluded that export marketing assistance program would be differentiated and specialized to fit in with exporters' different exporting stages and needs. Also, in order to increase the use of the programs, exporters' awareness and knowledge of the programs have to be increased in advance.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.4-14
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• 2005

CarboKorea and HydroKorea are the domestic projects aiming to improve our understanding of carbon and water cycles in a typical Korean forest located in a complex terrain with a watershed connected to large rivers. The ultimate goal is to provide a nowcasting of these cycles for the whole Peninsula. The basic strategy to achieve such goal is through the inter- and multi-disciplinary studies that synthesize the in-situ field observation, modeling and remote sensing technology. The challenge is the fact that natural ecosystems are nonlinear and heterogeneous with a wide range of spatio-temporal scales causing the variations of mass and energy exchanges from a leaf to landscape scales. Our paradigm now shifts from temporal variation at a point to spatial patterns and from spatial homogeneity to complexity of water and carbon at multiple scales. Yet, a large portion of our knowledge about land-atmosphere interactions has been established based on tower observations, indicating that the development of scaling logics holds the key to the success of CarboKorea and HydroKorea. Here, we review the pioneering work of FIFE (First ISLSCP Field Experiment) on scaling issues in a temperate grassland and discuss the lessons from it for the application to Gwangneung forest site.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.491-500
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• 2003

The need for network security is being increasing due to the development of information communication and internet technology, In this paper, firewall models, operating system models and other network component models are constructed. Each model Is defined by basic or compound model using MODSIM III. In this simulation environment with representative attacks, the following attacks are generated, SYN flooding and Smurf attack as an attack type of denial of service. The simulation is performed with the models that exploited various security policies against these attacks. In addition, the results of the simulation show that the analysis of security performance according to various security policies, and the analysis of correlation between availability and confidentiality according to security empowerment.

• Steel and Composite Structures
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• v.27 no.5
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• pp.647-659
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• 2018

Through extensive research, there exist a new type of connection between railway bridge girders and steel-concrete composite panels. In addition to conventional shear connectors, newly developed blind bolts have been recently adopted for retrofitting. However, the body of knowledge on their influence and application to railway structures has not been thoroughly investigated. This study has thus placed a particular emphasis on the application of blind bolts on the Sydney Harbour Bridge as a feasible alternative constituent of railway track upgrading. Finite element modeling has been used to simulate the behaviours of the precast steel-concrete panels with common types of bolt connection using commercially available package, ABAQUS. The steel-concrete composite track slabs have been designed in accordance with Australian Standards AS5100. These precast steel-concrete panels are then numerically retrofitted by three types of most practical bold connections: head studded shear connector, Ajax blind bolt and Lindapter hollow bolt. The influences of bolt connections on load and stress transfers and structural behaviour of the composite track slabs are highlighted in this paper. The numerical results exhibit that all three bolts can distribute stresses effectively and can be installed on the bridge girder. However, it is also found that Lindapter hollow bolts are superior in minimising structural responses of the composite track slabs to train loading.

• Asian Journal for Public Opinion Research
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• v.1 no.3
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• pp.217-231
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• 2014

This study begins with a review of commonly discussed dimensions of public risk perception that may influence public opinion toward risks. Factors that have been revealed by the literature to have substantial impact on risk perception, such as demographic background, trust, and media environment, are also discussed. Meanwhile, we evaluate two well-known research models in the realm of risk analysis: 1) the psychometric paradigm, and 2) the social amplification of risk framework (SARF). Based on a literature review, this study suggests that, besides the psychological and social approach, models of risk perception and risk communication research should shift to a more comprehensive one by considering the interrelations between laypeople and the environment. This study proposes a research model from the perspective of social cognitive theory (SCT) as a potential framework for future studies: 1) in the societal environment, individuals' risk perception and information seeking behavior, which is determined by risk perception will be influenced by trust in regulators and interpersonal trust; 2) in the media environment, individuals' risk perception and information seeking behavior will be influenced by individuals' perceived information characteristics. Knowledge about risk accumulated through information seeking will change risk perception in a longitudinal process.

• The Journal of Asian Finance, Economics and Business
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• v.4 no.2
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• pp.45-53
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• 2017

The main purpose of this study is to investigate the factors that have an impact on public policy, green products and technology in Kuala Lumpur, given government initiatives to boost the environment awareness. The data used in this study was collected by distribution questionnaires randomly in six areas of Kuala Lumpur and 400 respondents were interviewed. Based on a literature review, three hypotheses were stated and tested using structural equation modeling (SEM). SEM is a statistical analysis method that involved two or more variables in analyzing structural relationships among the variables. The SEM model shows that green products and government policies have a direct influence on environmental awareness. However, green technology does not have a direct influence on environmental awareness. Since, knowledge on green technology does not have a significant impact on raising environmental awareness among the public, a much more pragmatic awareness campaign needs to be put in place to use green technology as a part of modern living. The study suggests that the urban population needs to be more aware of the environmental issue as cities tend to have better infrastructure to raise public awareness on green issues. Moreover, the government should increase the environmental awareness among younger generation through workshops, seminars, campaigns, and pamphlets.