• Korean Journal of Remote Sensing
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• v.20 no.1
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• pp.57-64
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• 2004

In GIS-based network analysis, topological measure of network structure can be considered as one of important factors in the urban transportation analysis. Related to this measure, it is known that the connectivity indices such as alpha index and gamma index, which mean degree of network connectivity and complexity on a graph or a circuit, provide fundamental information. On the other hand, shimbel index is one of GIS-based spatial metrics to characterize degree of network concentration. However, the approach using these quantitative indices has not been widely used in practical level yet. In this study, an application program, in complied as extension, running on ArcView- GIS is implemented and demonstrated case examples using basic layers such as road centerline and administrative boundary. In this approach, geo-spatial imagery can be effectively used to actual applications to determine the analysis zone, which is composed of networks to extract these indices. As the results of the implementation and the case examples, it is notified that alpha and gamma indices as well as shimbel index can be used as referential data or auxiliary information for urban planning and transportation planning.

• Journal of the Korean housing association
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• v.19 no.5
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• pp.111-120
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• 2008

The aim of this study is to present the design methods about manifold location being installed and size and to draw out the proper piping size as comparing the fluctuation of discharge with manifold size and residence size through the piping network analysis, when using the same faucet in accordance. The findings are summarized as follows, 1) an appropriate header main body pipe diameter was deemed to be $32{\sim}50\;mm$. 2) the research presented design measures for the application of appropriate water supply inlet pipe diameters according to residential buildings with various sizes. 3) the header direct branch piping method is ideal for small and medium-sized residential complexes, and the header branching and semi header methods are deemed to be more favorable for large residential complexes. 4) this study offered design measures for appropriate header system main body pipe diameters, water supply inlet pipe diameters, header system piping methods, application methods for functional auxiliary equipment units, and header system installation spaces and location.

• Tunnel and Underground Space
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• v.4 no.1
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• pp.1-16
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• 1994

The study on the flow characteristics and analysis of groundwater in discontinuous rock mass is very important, since the water inflow into the underground opening during excavation induces serious stability and environmental problems. To investigate the flow through single rock joint, the effect of various aperture distribution on the groundwater flow has been analyzed. Observed through the analysis is the "channel flow", the phenomenon that the flow is dominant along the path of large aperture for given joint. The equivalent hydraulic conductivity is estimated and verified through the application of the joint network analysis for 100 joint maps generated statistically. Both the analytic aproach based on isotropic continuum premise and the joint network analysis are tested and compared analyzing the gorundwater inflow for underground openings of different sizes and varying joint density. The joint network analysis is considered better to reflect the geometric properties of joint distribution in analyzing the groundwater flow.ater flow.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.882-887
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• 2014

In this paper, the water cooling method among the forced coolant cooling methods is considered to be applied to the 110kW-class IPMSM for railway vehicles. First, basic thermal property analysis of the IPMSM is conducted using the three-dimensional thermal equivalent network method. Then, based on the results of the basic thermal property analysis, some design requirements for the water cooling jacket are deduced and a basic design of the water cooling jacket is carried out. Finally, thermal equivalent circuit of the water cooling jacket is attached to the IPMSM's 3D thermal equivalent network and then, the basic thermal and effectiveness analysis are conducted for the case of applying the water cooling jacket to the IPMSM. In the future, the thermal variation trends inside the IPMSM by the application of the water cooling jacket is expected to be quickly and easily predicted even at the design step of the railway traction motor.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.321-329
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• 2007

This paper reports on the application of network analysis approaches to investigate the characteristics of graph representations of Japanese word associations. Two semantic networks are constructed from two separate Japanese word association databases. The basic statistical features of the networks indicate that they have scale-free and small-world properties and that they exhibit hierarchical organization. A graph clustering method is also applied to the networks with the objective of generating hierarchical structures within the semantic networks. The method is shown to be an efficient tool for analyzing large-scale structures within corpora. As a utilization of the network clustering results, we briefly introduce two web-based applications: the first is a search system that highlights various possible relations between words according to association type, while the second is to present the hierarchical architecture of a semantic network. The systems realize dynamic representations of network structures based on the relationships between words and concepts.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.97-116
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• 2003

Frequency of attacks on web services and the resulting damage continue to grow as web services become popular. Techniques used in web service attacks are usually different from traditional network intrusion techniques, and techniques to protect web services are badly needed. Unfortunately, conventional intrusion detection systems (IDS), especially those based on known attack signatures, are inadequate in providing reasonable degree of security to web services. An application-level IDS, tailored to web services, is needed to overcome such limitations. The first step in developing web application IDS is to analyze known attacks on web services and characterize them so that anomaly-based intrusion defection becomes possible. In this paper, we classified known attack techniques to web services by analyzing causes, locations where such attack can be easily detected, and the potential risks.

• Journal of Korea Multimedia Society
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• v.18 no.4
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• pp.524-532
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• 2015

All data created in BigData times is included potentially meaning and correlation in data. A variety of data during a day in all society sectors has become created and stored. Research areas in analysis and grasp meaning between data is proceeding briskly. Especially, accuracy of meaning prediction and data imbalance problem between data for analysis is part in course of something important in data analysis field. In this paper, we proposed data prediction model based on data weights and neural network using R for meaning analysis between data. Proposed data prediction model is composed of classification model and analysis model. Classification model is working as weights application of normal distribution and optimum independent variable selection of multiple regression analysis. Analysis model role is increased prediction accuracy of output variable through neural network. Performance evaluation result, we were confirmed superiority of prediction model so that performance of result prediction through primitive data was measured 87.475% by proposed data prediction model.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.822-828
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• 2005

Customer satisfaction becomes one of the important managerial concerns associated with corporate competency in current competitive environment for Internet communication service companies. Hence, it is demanding to improve a company's customer satisfaction through the total quality management perspective. In practice, engineers as well as the management hope to find major quality characteristics with Internet communication network that is closely related to customer satisfaction, consequently aiming to the raise of their company's customer satisfaction. This paper presents an empirical relationship analysis between network quality characteristics and customer satisfaction on Internet communication. Methodologically, the relationship analysis framework is based on the regression variable selection procedures. In this framework, it is implemented that; 1) iterative model building; and 2) consistent criteria application to statistical tests for selecting significant variables. A case study shows that; 1) the customer satisfaction on the network connection seems to be more closely related to the network quality characteristics compared with the customer satisfaction on the network speed; and 2) the download disconnection rate has relatively evident relationship with the customer satisfaction on the network connection.

• Journal of Korea Trade
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• v.24 no.7
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• pp.1-28
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• 2020

Purpose - This paper empirically investigates the predictors and main determinants of consumers' ratings of mobile applications in the Google Play Store. Using a linear and nonlinear model comparison to identify the function of users' review, in determining application rating across countries, this study estimates the direct effects of users' reviews on the application rating. In addition, extending our modelling into a sentimental analysis, this paper also aims to explore the effects of review polarity and subjectivity on the application rating, followed by an examination of the moderating effect of user reviews on the polarity-rating and subjectivity-rating relationships. Design/methodology - Our empirical model considers nonlinear association as well as linear causality between features and targets. This study employs competing theoretical frameworks - multiple regression, decision-tree and neural network models - to identify the predictors and main determinants of app ratings, using data from the Google Play Store. Using a cross-validation method, our analysis investigates the direct and moderating effects of predictors and main determinants of application ratings in a global app market. Findings - The main findings of this study can be summarized as follows: the number of user's review is positively associated with the ratings of a given app and it positively moderates the polarity-rating relationship. Applying the review polarity measured by a sentimental analysis to the modelling, it was found that the polarity is not significantly associated with the rating. This result best applies to the function of both positive and negative reviews in playing a word-of-mouth role, as well as serving as a channel for communication, leading to product innovation. Originality/value - Applying a proxy measured by binomial figures, previous studies have predominantly focused on positive and negative sentiment in examining the determinants of app ratings, assuming that they are significantly associated. Given the constraints to measurement of sentiment in current research, this paper employs sentimental analysis to measure the real integer for users' polarity and subjectivity. This paper also seeks to compare the suitability of three distinct models - linear regression, decision-tree and neural network models. Although a comparison between methodologies has long been considered important to the empirical approach, it has hitherto been underexplored in studies on the app market.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1101-1104
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• 2002

In order to send the information certainly via the network against the packet lost caused by hardware troubles or limitation of packet transferring, we must construct reliable network infrastructure. However, it is difficult to construct comfortable network early if we construct rely on the prediction or the experience through a lot of troubles. In this paper, we propose the method to construct reliable network infrastructure based on the computer network simulation. This simulation is based on the percolation model. Percolation model is known as the model that represents connections. We gave some simulations for the various network topologies: the square lattice network, the cubic lattice network, and the full connection type network.