• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.193-195
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• 2003

This paper presents an approach to estimate the power transmission line parameter by phasor measurement units(PMUs), which are synchronized to 1 pps signal of GPS. Existing approaches to estimate power transmission line parameter, are mainly off-line ones, based on faults or switching events on other neighboring lines. In this paper, to obtain static and dynamic properties of power transmission line parameter in service, the prototype of pmu-based Transmission Line Parameter Monitoring System (TLPMS) is proposed. Also, an technique to estimate parameters of transmission line described as 2-port network model and the soundness of estimated parameters are addressed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.339-350
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• 1994

This paper presents a method for automatic generation of line balanced assembly sequences based on disassemblability and proposes a method of evaluating an assembly work time using neural networks. Since a line balancing problem in flexible assembly system requires a sophisticated planning method, reasoning about line balanced assembly sequences is an important field of concern for planning assembly lay-out. For the efficient inference of line balanced assembly sequences, many works have been reported on how to evaluate an assembly work time at each work station. However, most of them have some limitations in that they use cumbersome user query or approximated assembly work time data without considering assembly conditions. To overcome such criticism, this paper proposes a new approach to mathematically verify assembly conditions based on disassemblability. Based upon the results, we present a method of evaluating assembly work time using neural networks. The proposed method provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible assembly application. An example study is given to illustrate the concepts and procedure of the proposed scheme.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.3
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• pp.58-64
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• 2005

Customer sensibility based recommendation agent system was developed to tailor to the customer the suggestion of goods and the description of store catalog in on-line shopping mall. The recommendation agent system composed of five modules and seven services including specialized algorithm. This study was to investigate the effectiveness of the customer sensibility based recommendation agent system in on-line shopping mall. This study asked 30 male and female students to perform the task in on-line shopping mall and facilitated them questionnaires. The questionnaires were administered to subjects to measure quality precision, ease of use, support of buying, purchasing power, future intention of the system. The study revealed that good part of the subjects positively evaluated the customer sensibility based recommendation system except for ease of use. The study on usability of the recommendation agent system has need to be performed in next. This paper shows that the satisfaction and the buying power of customers may be improved by presenting customer sensibility based recommendation in on-line shopping mall.

• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.395-408
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• 2005

Ubiquitous computing spans a very broad range of technologies and needs very complicated user's requirements. There are many scenarios and technologies involved in ubiquitous computing. We need new software development tools and methodology to meet the requirements. A software product line is one of promising new technology for it. A software product line is a set of software intensive systems that share a common, managed set of features satisfying the specific needs of a particular market segment or mission and that are developed from a common set of core assets. Software architecture-based development is the exploration and maturation of the role of software architecture in the product line life cycle. In this thesis, we identify the foundational concepts underlying software product lines and the essential activities to develop the mobile application systems. So, we define, design, and implement the Mobile Application System Architecture(MASA) that includes the development process for applying into mobile business domain and encompass scoping and gathering requirements for the Product line based on Component Based Development(CBD).

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.235-240
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• 2007

A ceramic stem based TO package incorporating a coplanar waveguide feed-line has been proposed allowing for 10 Gbps grade data transmission. The frequency response of a cylindrical feed-line fer a conventional metal based TO package was first analyzed, and compared with that of the CPW feed-line used for a ceramic based package such as a butterfly package. For the case where a DFB LD chip is packaged to an LD module, the measured 3 dB frequency bandwidths for the conventional and proposed packages were 3.5 GHz and 7.8 GHz respectively, which agree well with the theoretical results obtained from the modeling based on the small signal equivalent circuits. Consequently, we proposed a novel ceramic based TO package with a CPW feed-line in ceramic material as a stem to improve the frequency characteristics of the conventional one. And, its performance was theoretically observed to confirm that the proposed package provides even wider frequency bandwidth compared to the conventional one.

• Applied Microscopy
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• v.44 no.2
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• pp.74-78
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• 2014

Dislocation density and distribution in epitaxial GaAs layer on Si are evaluated quantitatively and effectively using image processing of transmission electron microscopy image. In order to evaluate dislocation density and distribution, three methods are introduced based on line-intercept, line-length measurement and our coding with line-scanning method. Our coding method based on line-scanning is used to detect the dislocations line-by-line effectively by sweeping a thin line with the width of one pixel. The proposed method has advances in the evaluation of dislocation density and distribution. Dislocations can be detected automatically and continuously by a sweeping line in the code. Variation of dislocation density in epitaxial GaAs films can be precisely analyzed along the growth direction on the film.

• Journal of the Korean Operations Research and Management Science Society
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• v.27 no.1
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• pp.75-94
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• 2002

The development of Information technologies huts contributed on-line training as one of important education methods. On-line training In firms, which is similar to e-learning or virtual education, provides trainees with more education opportunities in diverse ways. It has developed a range of innovative services with an one-stop solution of education within the electronic sector. Also under the on-line training environment, trainees can undertake customized training packages at anytime and any places. Moreover, information technology allows both the trainers and other trainees to be decoupled in any of the elements of time, place, and space. Two research questions are investigated : what are the determinants affecting the on-line training effectiveness and how those variables effect the two aspects of training effectiveness: learning performance and transfer performance. Based on the previous literature conducted on the traditional training environment, the determinants of training effectiveness are derived. light hypotheses are developed based on literature reviews and tested by questionnaires survey data. The collected data have been analyzed by LISREL. It is found that the relationship between individual, organizational and on-line sloe design variables and training effectiveness (learning and transfer) are significant. The contribution and limitations of this research are also discussed tilth future studies.

• Journal of Distribution Research
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• v.10 no.1
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• pp.59-84
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• 2005

Most of previous studies have proposed representative product categories which are likely to be sold on the on-line based only on the on-line benefits and risks. However, on-line shopping can be perceived another form of distribution channels from the perspectives of consumers. Therefore, in order to identify product categories which have a great potential to be sold on on-line stores, it is necessary to consider the perception and behavior at off-line shopping contexts as well as on on-line shopping circumstances. In this paper, we investigate the consumers' perception and behavior under both on-line and off-line shopping situations and classify them into several groups based on their perceptual and behavioral characteristics. Based on this classification, we empirically examine the product categories selling well on the on-line shopping. The empirical results show that there exist some patterns between distribution channels (on-line and off-line) and product categories. In addition, there are some differences among consumers regarding the perceptions and behaviors at on-line and off-line situations. Consumers who have high preference for on-line shopping tend to buy much wider product categories from on-line.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.2
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• pp.327-338
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• 2018

On-line/off-line signature is a technique for performing heavy computations required for signature generation in the off-line stage and completing the final signature by a simple operation in the online stage. This is suitable for application environments that require immediate signing responses to multiple users. In this paper, we propose two new on-line/off-line signature schemes based on RSA problem. The first technique can generate a signature with a fixed base exponentiation when signing online, and the second technique can complete an online signature with a very simple calculation such as a hash operation. The security of both signatures is based on the RSA problem, which is proven to be tightly secure without security loss in the random oracle model.

• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.47-53
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• 2009

We define product line (or mix) selection problem as selecting a subset of potential product variants that can simultaneously minimize product proliferation and maintain market coverage. Selecting the most efficient product mix is a complex problem, which requires analyses of multiple criteria. This paper proposes a method based on Data Envelopment Analysis (DEA) for product line selection. Data Envelopment Analysis (DEA) is a linear programming based technique commonly used for measuring the relative performance of a group of decision making units with multiple inputs and outputs. Although DEA has been proved to be an effective evaluation tool in many fields, it has not been applied to solve the product line selection problem. In this study, we construct a five-step method that systematically adopts DEA to solve a product line selection problem. We then apply the proposed method to an existing line of staplers to provide quantitative evidence for managers to generate desirable decisions to maximize the company profits while also fulfilling market demands.