• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.594-596
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• 2003

Due to the fact that the composition and variability of aerosols is considered rather complex, it is difficult to employ a simple and straightforward physical model in calculating the aerosol size distribution in the absence of actual data. This complicates the already difficult retrieval of various atmospheric parameters from remotely sensed data. Thus, the main purpose of this study is trying to find an effective aerosol size coefficient that is stable, and can depict the particle size distribution. This paper also attempts to construct an 'effective aerosol size coefficient' database for each respective season, where it can quickly and effectively supply pertinent information of the atmosphere's opacity.

• Korean Journal of Construction Engineering and Management
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• v.13 no.6
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• pp.63-70
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• 2012

The apartment house taking most part of our housing types was facing the limit of consumption from the housing supply-oriented policy in the past of rapid urbanization resulting in being transferred to the housing supply-oriented one. Accordingly the requirement for housing quality by customers is diversified varied, in order to meet this the effective and systematic quality control for preventing the defects from the stage of building is required. In this study for the effective and systematic quality management for defects of apartment house analysis on the frequencies and loss expenses from defective maintenance regarding examples of apartment houses having been moved in within five years recently, and the survey on their dwellers' consciousness were made, and the table for quantified apartment house defective risk.

• Proceedings of the Korea Technology Innovation Society Conference
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• 1998.05a
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• pp.17-17
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• 1998

As the environment of the info-telecommunications policy is rapidly changing, the issue of promoting the informatization is emerging as a primary one of a government. In this sense, it is getting more recognized that, the informatization strategies centering on network-building should be interconnected with the issues of promoting the applications. Since the strategies to promote the informatization would necessarily result in the development, supply, and usage of the applications, needed are the consideration of policy directions to develop, supply, and use the applications effectively and of desirable policy means to carry them out. This study analyses the policies, which were related the issue of promoting the national informatization. And, this study also proposes the useful policy directions for an effective establishment of the applications in order to promote the national informatization.

• Solar Energy
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• v.18 no.3
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• pp.147-151
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• 1998

Several PV-diesel hybrid systems were built in isolated islands in Korea, where they are far from the inland to be supplied the electric power to a utility level from it. A lot of efforts has been concentrated to find a cost-effective electric supply system with higher reliability and minimum maintenance when compared with a diesel generator. For this purpose, an autonomous PV-diesel hybrid system with multi-channel remote monitoring system was investigated to supply electric power under minimum operating cost and maintenance in a small isolated island. In this report, the economic analysis was performed for comparison with photovoltaic system and diesel generator by computer simulation. And it was proven that a PV system is more cost-effective than an internal combustion engine for the remote island with less than 150 households. Especially, in the case of islands with less than 50 households, the initial construction cost of the PV system is comparable to and its operating cost is about 70% less than the diesel generator.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.10
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• pp.947-955
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• 2005

For the purpose of evaluating the thermal performance for air-barrier air conditioning system in perimeter zone, two air-conditioning systems, conventional perimeter air-conditioning system and air-barrier system, are evaluated and compared by scale model experiment and simulation during cooling season. As a result, measurement shows that supply air velocity of 1 m/s in the upstream direction at perimeter is more effective. Air-barrier system could reduce the cooling energy by $10\sim20\%$ compared with conventional system. Numerical simulation was carried out considering solar effect for reliable result. This method has improved the accuracy of numerical simulation for the space affected by the solar radiation. Both measurement and simulation results show that supply air velocity of 1 m/s at perimeter is the most effective.

• Journal of Hydrospace Technology
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• v.2 no.2
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• pp.44-56
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• 1996

The effects of the air on the reductions in resistance when supplied under the bottom of a semi-planing ship with a step are investigated in the present study. A 1.275m long FRP model is constructed and the pressure and viscous tangential stresses over the planing surface of the hull with and without air supply are measured through measuring holes carefully selected at the towing tank of Seoul National University. Locations of holes most suitable for air injection are surveyed in front of the planing surface of the model with careful examinations of the limiting streamlines and pressure distributions measured without air supply. At those locations, found to be just front of the step, air has been supplied into a wake region to form an air filled cavity of fixed type. Flow rates and pressure of the supplied air as well as the local pressure and shear stress distributions on the hull surface are measured to understand the physics involved as well as to determine the conditions most effective in resistance reduction at the design speed. It has been found that total resistance of the stepped semi-planing hull can be considerably reduced if an air cavity generated by an adequate air injection at the bottom of the hull near the step. After the cavity optimized at the given speed, air bubbles also have been generated right behind the point where dividing streamlines re-attach to further reduce the frictional resistance but found to be not so effective as the air cavity in resistance reductions.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.3
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• pp.61-80
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• 2010

Recently, the publishing community now recognizes the importance of metadata in customers' buying decisions. As a result, they are more interested in effective metadata creation and quality maintenance, as well as standardization of exchanging system in the supply chain. As the library community also investigates the economic effectiveness of creating metadata, they try to find the best model for simplifying metadata creation by using sources close to the original. This study analyzes metadata work flow which had same source but be used in different fields by their own type and standard. It also discusses the same issues about each section and possibility about interoperation. Finally this paper tries to find an effective creation and distribution model of book metadata which can be used in domestic publishing and the library community.

• Advances in nano research
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• v.15 no.5
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• pp.441-449
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• 2023

Heavy metals, widely present in the environment, have become significant pollutants due to their excessive use in industries and technology. Their non-degradable nature poses a persistent environmental problem, leading to potential acute or chronic poisoning from prolonged exposure. Recent research has focused on separating heavy metals, particularly from industrial and mining sources. Industries such as metal plating, mining operations, tanning, wood and chipboard production, industrial paint and textile manufacturing, as well as oil refining, are major contributors of heavy metals in water sources. Therefore, removing heavy metals from water is crucial, especially for safe water supply in swimming and water sports. Iron oxide nanoparticles have proven to be highly effective adsorbents for water contaminants, and efforts have been made to enhance their efficiency and absorption capabilities through surface modifications. Nanoparticles synthesized using plant extracts can effectively bind with heavy metal ions by modifying the nanoparticle surface with plant components, thereby increasing the efficiency of heavy metal removal. This study focuses on removing lead from industrial wastewater using environmentally friendly, cost-effective iron nanoparticles synthesized with Genovese basil extract. The synthesis of nanoparticles is confirmed through analysis using Transmission Electron Microscope (TEM) and X-ray diffraction, validating their spherical shape and nanometer-scale dimensions. The method used in this study has a low detection limit of 0.031 ppm for measuring lead concentration, making it suitable for ensuring water safety in swimming and water sports.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.57-66
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• 1991

This study was carried out for 5 years between 1984 and 1986 and 1989 and 1990. This interviewers visited 292 households to evaluate the perception of the residents using .the. Simple Piped Water Supply (SPWS), and examined the pollution source surrounding 42 SPWS facilities and water quality by the chemical and microbiological method. The purpose of this study was to find out problems linked with SPWS and to investigate more efficient way of improvement in rural water supply. The results of the study are surmnarized as follows: 1) Approximately 55% of the sampled population have been served by simple piped water supply. 2) The drinking water was mostly taken from the springs in 16 sites and valley water in 26 sites. 3) Considering the type of distribution of the SPWS, there are 28 natural gravity systems and 14 pumping systems. 4) Out of the 180 SPWS in Chun Sung Area, 74% of the SPWS facilities were used more than ten years. In addition, 40% of residents expressed the need for repairs of old facilities. 5) 48% of the SPWS facilities are neighbored with pollution source. 6) 50% of the maintenance crews were not committed totheir job but instead, the facilities were operated by some residents or community leaders who were personally concerned about quality of the facilities. 7) About 85% of the residents answered that SPWS was convenient and helpful. 8) About 57% of the residents complaind that the amount of daily water supply is not adequate. 9) About 74% of the residents felt that the water quality is high for dringking water and therefore, 52% of the facilities were not properly chlorinated. But in contrast, the biochemical tests indicated that only 28% of the SPWS met the dringking water quality standards. 10) Maintenance cost per a household ranges form 500 to 2, 000Won (1 $ = 700 Won) a month. Most of the cost was to cover the power electric charge. For the effective maintenance and arrangement of the facilities, gorvermental financial support for the maintenance is strongly recommended.

• Journal of the Korea Society of Computer and Information
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• v.17 no.5
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• pp.169-176
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• 2012

The supply chain of online digital contents industry differs much from the supply chain of offline industry which produces and supplies physical products. Portal facilitates the creation, distribution, and usage of online digital contents by providing efficient and convenient content distribution platform to contents suppliers and users, resulting in enhancing competitiveness of portal supply chain. Each portal builds it's own supply chain and various participant firms like CPs(Content Providers) and SPs(Solution Providers) are collaborating together to survive from the fierce competition. However, there is few research work on portal SCM to explain how to design and implement a Portal SCM in a successful way. So, this paper investigates the structure of Portal SCM and the differences between traditional SCM and Portal SCM. Also, this paper proposes seven research issues need to be addressed to design and implement a portal in an efficient and effective way.