• Journal of KIISE:Software and Applications
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• v.36 no.11
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• pp.891-900
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• 2009

The priority of software maintenance researches has been increasing, since the lengths of software lifecycle are more increasing. Measuring couplings among software entities provides a good quantitative source for analyzing source code and point out candidate refactoring positions. Logical-coupling measures how strongly two software entities are related with each other from the evolutionary point of view. The researches on logical-coupling have been focusing on improving the correctness and explaining more aspects that are hiding by measuring logical-coupling among finer-grained entities. However, existing researches on logical-coupling fails to consider characteristics of developers and projects reflected in transactions. The research proposes a logical-coupling measurement method based on transaction time, size and expertise of developer to improve the correctness by considering characteristics of developers and projects reflected in transactions. The method has been validated by applying it to three open-source projects.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.7-13
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• 1998

The VLSI devices of submicron level trend to have a lowering of reliability because of hot carriers by two dimensional influences which are caused by short channel effects and which are not generated in a long channel devices. In order to minimize the two dimensional influences, much research has been made into various types of source/drain structures. MOS typed tunnel transistor with Schottky barrier junctions at source/drain, which has the advantages in fabrication process, downsizing and response speed, has been proposed. The experimental device was fabricated with p type silicon, and manifested the transistor action, showing the unsaturated output characteristics and the high transconductance comparing with that in field effect mode. The results of trial indicate for better performance as follows; high doped channel layer to lower the driving voltage, high resistivity substrate to reduce the leakage current from the substrate to drain.

• Journal of Environmental Science International
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• v.32 no.9
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• pp.647-657
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• 2023

The study analyzes the forest status of each local government for Korean forests and believes that it can be used as basic data for setting the direction pursued by each local government. The study took into account the fact that the forest rate in Korea was 63.5%, because it was judged that the higher the proportion of forest area, the more important it was to use the characteristics of forests. The characteristics of forests were analyzed based on four factors in 12 factors to identify the location of the ground body by dividing seven types. In addition, basic information on carbon absorption sources was provided by grasping the ability of carbon absorption sources per year through the amount of forest resources to be analyzed. In addition, as a result of analyzing the characteristics of the weather for the promotion of carbon absorption sources, the flat area on the side of Gangneung Mountain was a warm forest with a warm index of 106.0.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.574-581
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• 2002

Traditional queueing analyses are very useful for designing a network's capacity and predicting their performances, however most of the predicted results from the queueing analyses are quite different from the realistic measured performance. And recent empirical studies on LAN, WAN, and VBR traffic characteristic have indicated that the models used in the traditional Poisson assumption cannot properly predict the real traffic properties due to underestimation of the long-range dependence of network traffics and self-similar properties. In this paper, It is also shown that the self-similar traffic reflects real Ethernet traffic characteristics by comparing Pareto-like ON/OFF source model which is exactly self-similar model to the traditional Poisson model. It is also performed optimization design and performance analysis of ATM network using Internet traffic characteristics.

• Journal of Information Management
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• v.32 no.2
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• pp.1-25
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• 2001

The purpose of this study Is to analyze and describe the characteristics of the information needs and information seeking behavior of ST information users of the KISTI. Questionnaires were distributed to the ST information users in the academic, industrial, and scientific sectors via mail. The role of the KISTI as the specialized information source and intermediary for other institutional information sources as well as individual users and the need for improving the strategies for customer-based services and collection development were evaluated. Major findings include the need for a more comprehensive effort to collect, preserve, and communicate the ST information resources. the need for much broader collection of journals and conference proceedings to provide the documents "on demand" for users, and the need to improve DDS in general.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.6
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• pp.34-42
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• 2002

In this paper, we propose a temperature independent the detective voltage source in voltage detector. The value of a detective voltage source is designed to become m times of silicon bandgap voltage at zero absolute temperature. By properly choosing the temperature coefficient of diode, the temperature coefficient of a concave voltage nonlinearities generated by the ${\Delta}V_{BE}$ section of diode between base and emitter of transistors with a different area can be summed with convex nonlinearities the $V_{BE}$ voltage to achieve the near zero temperature coefficient of the detective voltage source. We designed that the value of a detective voltage can be varied by ${\Delta}V_{BE}$, the $V_{BE}$multiplier circuit and resistor. In order to verify the performance of a proposed detective voltage source, we manufactured the voltage detector IC for 1.9V which is fabricated in $6{\mu}m$ Bipolar technology and measured the operating characteristics, the temperature coefficient of a detective voltage. To reduce the deviation of a detective voltage in the IC process step, we introduced a trimming technology, ion implantation and an isotropic etching. In manufactured IC, the detective voltage source could achieve the stable temperature coefficient of 29ppm/$^{\circ}C$ over the temperature range of -30$^{\circ}C$ to 70$^{\circ}C$. The current consumption of a voltage detector constituted by the proposed detective voltage source is $10{\mu}A$ from 1.9V-supply voltage at room temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.74-76
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• 2006

An external electrode fluorescent lamp (EEFL) has an advantage of a long lifetime in the ear1y stages of the study on plasma discharge, interest in the lamp continues. Researches on the operation of external electrode fluorescent lamps have focused mainly on its use of a type of high frequency (MHz). By performing high brightness using a square wave operation method with the low frequency below 100kHz, which is applied to a narrowed tube type lamp that has several mm of lamp diameter, EEFL presented the possibility of using it as a light source for back-lights. However, because EEFL generates plasma using wall charges, which considers the impedance characteristics of glass based on the structural principle in discharge, it can be significant1y affected by frequency. Thus, this study verified the change in the characteristics of electromagnetic fields according to the change in frequency through a Maxwell's electromagnetic field simulation and examined the relationship between the change in the EEFL frequency and brightness by measuring the optical characteristics. In addition, the characteristics of the transformation of energy orbits were verified by investigating the characteristics of the wavelength according to the change in frequency through the OES.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1590-1597
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• 1999

Advertisements on the Web, rising as a major profit source of Web services, have a distinctive characteristic of detailed classification of potential customers, compared with those of other conventional media such as TV and newspaper. It is therefore possible to advertise selectively according to personal characteristics and to record precise advertisement effects. Web-based advertisement management systems of nowadays have the capability to select ones compatible with personal environment characteristics and registered information, and to provide processed information and knowledge about advertisement effects based on usage recordings. However, they have severe problems in modeling diverse requirements or characteristics of users : customers, advertisers and ISP, and in matching and coordinating of them. In order to solve these problems, we propose a frame work for coordinating the needs of users, advertisers, and ISPs, which is built on top of tree-style classification of advertisements. Other schemes are supported around the framework as follows : (1) characteristics management of pages within themselves, (2) rule-based modeling of advertisement target, and (3) user modeling and case-based analysis. We propose a prototype system within the framework.

• Journal of ILASS-Korea
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• v.21 no.4
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• pp.223-236
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• 2016

On-road source emissions are major air pollutants and have been associated with serious health effects in Seoul metropolis. Thus, it is of fundamental importance to have an accurate assessment of vehicle emissions in order to implement an effective air quality management policy. As a result, there is a need to overview vehicle emission characteristics of air pollutants. This article discusses vehicle exhaust sampling and chemical analysis, emission characteristics of air pollutants, and emission regulations from passenger cars. The vehicle exhaust sampling and chemical analysis methods were described in particulate matter and gaseous compounds. In this article, chassis dynamometer, measurement instrumentation for nano-particulate matter and carbon compounds analysis device were described. For the gasoline and diesel vehicles, the effective parameters of emissions were average vehicle speed, vehicle mileage and model year. The particle number emissions for diesel nano-particles were sensitive to the sampling conditions. Also, the particle number emissions with a diesel particle filter (DPF) largely reduced rather than those without it. This article also describes different emission characteristics of air pollutants according to biodiesel or bioethanol mixing ratio. The Korean emission standards for passenger cars were compared with those of the US and EU. Finally, the objective is to give an overview of relevant background information on emission characteristics of air pollutants from passenger cars in Korea.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.262-275
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• 2021

The expansion of the online market is expected to change the purchasing environment. The purpose of this study is to examine the difference in the moderating effect of each characteristic on perceived quality and purchase intention according to the group according to product involvement and purchaser age. The first step is to identify the characteristics of online information sources and social media platforms through a literature review. Next, when perceived quality affects purchase intention, we verify the moderating effect according to the characteristics of online information sources and social media platforms. The moderating effect is verified at the stage by dividing it into a group according to product involvement and a group according to age. The following results were confirmed throughout the study: First, perceived quality significantly affects purchase intention. Second, in the relationship between perceived quality and purchase intention, the influence of the moderating effect is different depending on the high-involvement product and the low-involvement product. Third, it was confirmed that there was a difference in the moderating effect of online information sources and social media platforms in the relationship between perceived quality and purchase intention according to age. This study intends to increase consumers' purchase intentions by identifying specific age groups and product groups of involvement and establishing strategies suitable for the characteristics of online information sources and social media platforms.