• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.4
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• pp.555-560
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• 2016

Recently, many countries have placed great attention on energy security and climate changes. Governments are promoting the construction of renewable energy projects with regulatory support in Korea. Despite an increasing penetration of renewable resources, however, the photovoltaic and wind power are underutilized due to the endemic problems such as difficulties of output control and intermittent output. The Energy Storage System (ESS) is proposed as a good solution for solving the problems and has been studied in both the private business and the government. However, because of inefficient aspects, the research has been carried out for improving high costs and a small capacity. In addition, the ESS is currently installed for using only one purpose which is frequency regulation or transmission congestion relief such that has an economic limitation. Therefore, methods which are becoming economically justifiable to increase the penetration of the ESS is required. Thus, this paper presents in terms of operation efficiency to improve economic feasibility of the ESS currently used. mainly, there are two aspects for the operation efficiency. Firstly, it is intended to improve the utilization rate through a process that can utilize the ESS for various purposes. It is necessary to be able to use for other purposes by classifying and clustering for increasing the efficiency of availability. The clustering method is proposed to conduct the grouping the ESS. Especially, it is proposed to utilize ESS for frequency regulation service which is the one of ancillary services in the power system. Through case studies, it is confirmed to secure the necessary resources by clustering small size ESS.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.147-155
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• 2014

While variety of content on the internet has increased with the development of IT and person's needs about suitable information are increasing rapidly, studies for personalized service have been actively performed. In the study, we proposed the Hypertension and Diabetes risk analysis system according to personal food intake preference using the analysis method of buying preferences in product recommendation system. For the analysis of food intake preference, the Pearson correlation coefficient is used to calculate similarity weights between each reference analysis data and sample data and then reference data should be grouping into the similarity weights and calculating risk of hypertension and diabetes each group. To evaluate the significance of this system, 1,021 subjects are applied the system. Hypertension and diabetes groups' risk is significant higher than normal group statistically so, it is confirmed that food intake preference and the diseases were relevant. In this paper, we verify the validity of hypertension and diabetes risk analysis system using a personal food intake preference.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.3 s.33
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• pp.87-94
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• 2005

3D positional information of lane can be automatically calculated tv combining GPS data, IMU data if coordinates of lane centers are given. The Road Safety Survey and Analysis Vehicle(RoSSAV) is currently under development to analyze three dimensional safety and stability of roads. RoSSAV has GPS and IMU sensors to get positional information of the vehicle and two road-facing CCD cameras for extraction of lane coordinates. In this paper, we develop technology that automatically detects centers of lanes from the road-facing cameras of RoSSAV. The proposed algorithm defines line-support regions by grouping pixels with similar edge orientation and magnitude together and extracts a line from each line support region by planar fitting. Then if extracted lines and the region in-between satisfy the criteria of brightness and width, we decide this region as lane. The proposed algorithm was more precise and stable than the previously proposed algorithm based on brightness threshold method. Experiments with real road scenes confirmed that lane was effectively extracted by the proposed algorithm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.81-86
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• 1990

This study aims to systemize the developement of the domestic girder bridges, and to contribute to the future construction of our own bridges. Bridges are analyzed by grouping them in terms of construction time and structural component. The bridges, which were constructed during the first era of Goryeo-dynasty, have no distinction between main beams and stone deck. Form the latter era of Goryeo-dynasty, the structure of the bridges began to seperate into main beams and stone deck in order to enlarge the width and span length. The bridges, which were constructed during the Chosun-dynasty, were constructed using modulized material, and are considered to be built by structural design concept. Their construction materials became larger due to the development of transportation method. The superstructure of the old Korean bridges became more complicated in contrast to simplification of the substructures.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.98-105
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• 2003

We propose a new technique of deinterleaving multiple radar pulse sequences by means of genetic algorithm for threat identification in electronic warfare(EW) system. The conventional approaches based on histogram or continuous wavelet transform are so deterministic that they are subject to failing in detection of individual signal characteristics under real EW signal environment that suffers frequent signal missing, noise, and counter-EW signal. The proposed algorithm utilizes the probabilistic optimization procedure of genetic algorithm. This method, a time-of-arrival(TOA) only strategy, constructs an initial chromosome set using the difference of TOA. To evaluate the fitness of each gene, the defined pulse phase is considered. Since it is rare to meet with a single radar at a moment in EW field of combat, multiple solutions are to be derived in the final stage. Therefore it is designed to terminate genetic process at the prematured generation followed by a chromosome grouping. Experimental results for simulated and real radar signals show the improved performance in estimating both the number of radar and the pulse repetition interval.

• Journal of Internet Computing and Services
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• v.8 no.3
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• pp.131-143
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• 2007

The current trends in information technology and intelligent systems use data mining techniques to discover patterns and extract rules from distributed databases. In distributed environment, the extracted rules from data mining techniques can be used in dynamic replications, adaptive load balancing and other schemes. However, transmission of large data through the system can cause errors and unreliable results. This paper proposes the intelligent distributed platform based on dynamic group binding using mobile agents which addresses the use of intelligence in distributed environment. The proposed grouping service implements classification scheme of objects. Data compressor agent and data miner agent extracts rules and compresses data, respectively, from the service node databases. The proposed algorithm performs preprocessing where it merges the less frequent dataset using neuro-fuzzy classifier before sending the data. Object group classification, data mining the service node database, data compression method, and rule extraction were simulated. Result of experiments in efficient data compression and reliable rule extraction shows that the proposed algorithm has better performance compared to other methods.

• Science of Emotion and Sensibility
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• v.5 no.1
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• pp.9-16
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• 2002

This study was designed to cluster the preferred sensibilities of college students, and to distinguish the most preferred sensibility according to gender and their inter-subject differences. 98 of sensibility adjectives were composed into questionnaire with SD method and the data of 176 students were analyzed in ANOVA, Cluster and Correspondence analysis using SAS package. College students were divided into 10-sensibility clusters: the Casual(no-decoration casual, cool-dynamic casual and elaborate-clean casual), the Romantic Modem, the Simple Natural, the Classic(craft-romantic classic and monotonous classic), the Expressionless, the Gorgeous, and the Traditional Folklore. The adjectives and the sensibility clusters of students were visualized together into 2-D with two axis of static vs. dynamic and light vs. heavy.

• The Journal of Korean Medicine
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• v.30 no.6
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• pp.86-95
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• 2009

Objectives: This study aimed to examine the difference of external appearance measurements in subjects of different regional lineages as subgroups within the Tae-eumin Sasang grouping. Methods: We chose 51 Tae-eumin subjects diagnosed by Korean Sasang constitutional medical doctors aided by voice analysis. The subjects were divided into two groups, the northern and southern lineages, by an expert on facial characteristics of the two lineages. We took pictures of their frontal and lateral views by Martin's method, measured projected length of face with the Facial Feature Measurement Program, and analyzed anthropometric facial differences between the northern and southern types. Results: Results show differences between the northern and southern types. First, the northern type of face has bigger measurements than the southern type on the frontal face. Second, the northern type of face has higher measurements of "height", which means distance from pupil to a specific measurement point, than the southern type on the frontal face. Third, on the frontal face, the northern and southern types have differences with respect to eyebrow, point of sellion, and eye. Fourth, on the side face, the northern and southern types have differences in lip, mandible and ear. Conclusions: We found our anthropometric facial measurements of the northern and southern lineages to be in accordance with previous literature. Knowledge of the differences between the northern and southern lineages can be a hint in constitutional diagnosis when differentiation is clinically confusing.

• The Journal of Information Systems
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• v.26 no.3
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• pp.1-23
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• 2017

Purpose With the advent of the 4th Industrial Revolution era, ICT convergence industry is leading the wave of new change. These changes in the industrial field are recognizing convergence as a strategic cooperation tool of management for creating new value. In order to achieve the research purpose, conceptual understanding of ICT convergence is summarized by focusing on concepts, features, types and cases. In addition, this study established the theoretical rationale for the determinants of ICT convergence performance, and examined previous researches related to ICT convergence. Design/methodology/approach The empirical research method is based on a survey of 510 companies including managers and mid-level practitioners who understand the contents of the relevant field, 305 data were used for analysis. We conducted exploratory factor analysis to verify the grouping of these questionnaire items and conducted confirmatory factor analysis to analyze the validity and reliability of the measurement model. Through the statistical analysis, we analyzed the structural relationship of ICT firms' competencies for convergence performance. Findings Linkage of ICT strategies established by corporations is an important factor for enhancing resource capacity and convergence ability. It is important to ensure that product innovation, consumer-oriented strategies, and ICT strategies for the implementation of business strategies are closely linked. In addition, in the convergence environment, companies should make efforts to develop convergence ability and improve organizational performance through utilization of ICT resources. From the CEO's perspective, it is necessary to understand the knowledge, technology and resources arising from the convergence environment, and to integrate with the resources possessed by the enterprise to induce the organization's performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1234-1244
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• 2009

Nowadays, the traffic type and behavior are extremely diverse due to the appearance of various services and applications on Internet, which makes the need of application-level traffic classification important for the efficient management and control of network resources. Although lots of methods for traffic classification have been introduced in literature, they have some limitations to achieve an acceptable level of performance in terms of accuracy and completeness. In this paper we propose an application traffic classification method using statistic signatures, defined as a directional sequence of packet size in a flow, which is unique for each application. The statistic signatures of each application are collected by our automatic grouping and extracting mechanism which is mainly described in this paper. By matching to the statistic signatures we can easily and quickly identify the application name of traffic flows with high accuracy, which is also shown by comprehensive excrement with our campus traffic data.