• Journal of Software Engineering Society
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• v.24 no.3
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• pp.77-89
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• 2011

Software product line engineering is a software reuse paradigm that helps organizations improve software productivity and quality by developing software products from reusable core assets. For the satisfaction of common and variable requirements among products in the product line, the core assets must be configurable according to the selection of variable features. Therefore, unlike software architecture model of a single product, product line architecture model must embed and express variabilities among the products. Many researches have proposed methods of embedding and expressing variabilities in the product line architecture models, but there are few comparative studies on the proposed methods. In this paper we discuss strong points and weak points of the proposed methods and compare expressiveness of the methods, which helps select a proper method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.2
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• pp.35-39
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• 2011

Error correcting codes with easy variability in code rate and codeword length in addition to powerful error correcting capability are required for present and future mobile multimedia communication systems. And low complexity is also needed for the compact mobile terminals. In general, the irregular random LDPC(low-density parity-check) code is known to have the superior performance among various LDPC codes. But it has inefficiency since the various parity check matrices for various services should be stored for encoding and decoding. The structured LDPC codes which can easily provide various rates and lengths are studied recently. Therefore, the flexibility, memory size, and error performance of various structured LDPC codes are compared and analyzed in this paper. And the most appropriate structured LDPC code is also suggested.

• The KIPS Transactions:PartD
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• v.13D no.4 s.107
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• pp.593-602
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• 2006

Software development methodology has been developed for satisfying goals of improvement in productivity and reduction in time-to-market through the reuse of software assets. The current methods that implement software product-line, one of software development methodologies, interfere massively with the core assets, which require high cost in assembly level reducing the effectiveness. In this paper, we introduce Aspect-Oriented Programming (AOP) as a method for improving assembly process in software product-line. The method that assembles core assets and variabilities is described by grammar elements such as Join point, pointcut and advice without code-change. We analyze requirements of a mini-system as an example adapting AOP and design using UML. Our study implements the variabilities, which are from design stage, using an Aspect-Oriented Programming Language, AspectJ and prove usability and practicality by implementing the proposed idea using an Aspect-Oriented Programming Language, AspectJ.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.2
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• pp.86-94
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• 2014

Optical packet switching (OPS) is being considered as one of the switching technologies for a future optical internet. For contention resolution in an optical packet switching (OPS) system, the wavelength dimension is generally used in combination with a fiber delay line (FDL) buffer. In this article, we propose a method to reduce the number of tunable wavelength converters (TWCs) by sharing TWCs for a cost-effective design of an asynchronous OPS system with a shared or an output FDL buffer. Asynchronous and variable-length packets are considered in the OPS system design. To investigate the number of TWCs needed for the OPS system, an algorithm is proposed, which searches for an available TWC and an unused internal wavelength, as well as an outgoing channel. This algorithm is applied to an OPS system with a shared or an output FDL buffer. Also, the number of internal wavelengths (i.e., the conversion range of the TWC) needed for an asynchronous OPS system is presented for cost reduction of the OPS system.

• Korean Journal of Optics and Photonics
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• v.10 no.2
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• pp.152-156
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• 1999

We have developed the pulse-width variable Quenched Dye Laser (QDL). QDL consisted of the dye cell of 5 mm length containing a $2.5{\times}10^{-3}$[mol/l] solution of Rhodamine 6G and the cylindrical lens focal length of 150 mm and quenching mirror. QDL system was pumped by s XeCl excimer laser with 150 mJ pulse energy in a 20 ns pulse at 1 Hz repetition rate. Pulse-width of QDL was measured by a noncollinear intensity autocorrelator. The focused thckness was measured by changing the position of the focusing cylindrical lens. Pulse-width of QDL as a function of the focused thickness (273.0${\mu}{\textrm}{m}$~845.0${\mu}{\textrm}{m}$) varied continuously from 86 ps to 201 ps.

• Journal of the Korean Society for Railway
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• v.17 no.5
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• pp.373-380
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• 2014

With a view to the commercialization of the Korean automatic variable-gauge bogie in the Eurasia railway system, the aim of this research was to perform an economic analysis concerning the possible introduction and operation of this bogie at the present time. For this purpose, we compared the possible types of freight connection service for container transportation, transshipment and the gauge-adjustable system, estimating the total life-cycle cost (LCC) incurred by each system, depending on type and quantity, over the whole process of acquisition, operation, maintenance and disposal. Based on this, we presented a case-by case analysis. Furthermore, in estimating economic feasibility, we analyzed the cost-benefit ratio taking into account not only the objective LCC, but also the reduced time required for the gauge-change and customer convenience. After estimating the LCC and analyzing the cost-benefit ratio of the respective systems, we demonstrated the economic superiority of view of the gauge adjustable system.

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.259-267
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• 2019

As the change in social awareness regarding cats is consistent with the lifestyle of modern people who seek an independent life, the number of cats owned as a pet and its market will continue to increase. The compainion animals are not just pets to pet owners, but people communicate with their pets and the pets have begun to be recognized as a member of their family. Although the pet industry has been steadily growing and the number of cats owned by households is rapidly increasing, there is a lack of study on products based on understanding the characteristics and behavior of cats. The purpose of this study is to propose a versatile furniture design considering the behavior characteristics of cats. The versatile furniture that is easy to move and rearrange according to necessity and the environment of residential space always pays to make better use of the space. We would like to propose versatile furniture that can satisfy the aesthetic pleasures of cats and can be used as furniture at the same time depending on purpose and situation. This study aims to develop the design of furniture that can make a better environment for pets and pet owners, an it is expected to be a basic study of furniture design for them.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1104-1111
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• 2003

The paper presents an algorithm for the compensation of gain and phase imbalances to exist between I-phase and Q-phase signal at direct conversion receiver. We propose a gain and phase imbalances blind equalization compensation algorithm by using variable step-size adaptive loop at direct conversion receiver. The blind equalization schemes have trade-off between convergence speed and jitter effect for the compensation of gain and phase imbalance. We propose the variable step-size adaptive loop method, which varies the loop coefficients according to errors, for recovering these problem. By using variable step-size adaptive loops, we propose to speed up the convergence process and reduce the jitter effect and simulation results show that the algorithm compensates signal loss and speeds up convergence time.

• Journal of KIISE:Software and Applications
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• v.32 no.3
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• pp.163-172
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• 2005

Product Line Engineering (PLE) has been widely accepted as a representative software reuse methodology by using core assets. Product line architecture (PLA) is a key element of core assets. However, current research works on designing PLA do not provide sufficient and detailed guidelines of defining PLA and reflecting variability in the architecture. In this paper, we present a reference model of PLA and propose a process to design PLA with detailed instructions. Especially architectural variability is codified by describing decision model depending variation points and traced through PLA activities. The proposed process would make it feasible to apply PLE to practice areas.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.206-209
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• 2005

Optimal path search systems to take continuously changed traffic flows into consideration is necessary in order to reduce the cost to get destination. However, to search optimal path in client terminals with low computing power yields high computational cost. Thus, a method with low cost and near optimal path as well is required. In this paper, we propose a path search method using variable heuristic for the sake of reducing operation time. The heuristic is determined by the change of the average speeds of cars located in grid which means a rectangle region.