• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.15-22
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• 2016

This study aims to analyze the changes in the benthic macroinvertebrate community before and after a restoration project in a eutrophic stream. Species diversity and species richness increased at the points where the channel changed from standing water to running water. However, species diversity and richness decreased at the points where only riparian restoration was implemented, and the concentration of suspended solids increased, while biochemical oxygen demand and total phosphorus decreased and the concentration of dissolved oxygen increased. In such reaches, functional feeding groups went from collector-filterers to collector-gatherers, and habitat orientation groups changed from clingers to burrowers.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.325-333
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• 2004

Since 1995, One of the NGIS(National Geographic Information System) projects, the underground utilities project has been finished in 2003. The 19 cities in korea for this project will use underground utilities management system using underground utilities database focusing on water and sewage system. However, special expert, technical and experience problem in computer environment has not been had in working department for water and sewage management and maintenance for each local government. The management and maintenance of underground utilities database by manual method is getting lowered a data quality of underground utilities database because of the data omitting, error in writing and securing of the lasted database. Therefore, in this study, Application test for field workers using a mobile tool and environment analysis of wireless communication in Korea and application test of GPS receiver for mobile tools had been processed and made a mobile working environment. The efficient management and maintenance method for underground utilities database has been developed an off- line method for modification and update of database about general work which has a high working frequency because of the limitation of wireless communication environment Also, the emergency working has been applied for on-line method.

• Journal of information and communication convergence engineering
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• v.10 no.1
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• pp.11-20
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• 2012

In a marine ubiquitous sensor network (USN) system using expensive sensors in the harsh ocean environment, it is very important to discover failures and devise recovery techniques to deal with such failures. Therefore, in order to perform failure modeling, this study analyzes the USN-based real-time water quality monitoring service of the Gaduri Aqua Farms at Songdo Island of Yeosu, South Korea and devises methods of discovery and recovery of failure by classifying the types of failure into system element failure, communication failure, and data failure. In particular, to solve problems from the perspective of data, this study defines data integrity and data consistency for use in identifying data failure. This study, by identifying the exact type of failure through analysis of the cause of failure, proposes criteria for performing relevant recovery. In addition, the experiments have been made to suggest the duration as to how long the data should be stored in the gateway when such a data failure occurs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.749-756
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• 2019

This study verified the effect of public service motivation volunteer work on educational training of maritime police recruits. Results show sub-factors of motive for public volunteer work, self-sacrifice, commitment to public good and positive perception of public policy affected educational satisfaction, but one other sub-factor, compassion, did not affect educational satisfaction. The practical implication is that assets without form and that which exist internally within the individual, such as spirit of public volunteering and spirit of self-sacrifice, can increase educational satisfaction. Unlike ground police, maritime police bear the danger of being on water, which necessitates the need for enhencing intagible assets like public sevice value.

• Journal of Food Hygiene and Safety
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• v.18 no.2
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• pp.79-86
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• 2003

Most of food poisoning is frequently raised from mass catering. Especially, staphylococci takes the large part of pathogenic agents which are related to the hygienic condition. Among total 98 samples, four staphylococci were isolated from food service environment such as drinking water (A), hands (D), refrigerator and apron (E) of 5 elementary school (A, B, C, D, E) in Gyeongnam Province. These isolated strains are characterized as 1 MRCNS (Methicilline Resistant Coagulase Negative Staphylococcus aureus) and 3 MSCPS (Methicilline Sensitive Coagulase positive Staphylococcus aureus). Also, production of enterotoxin B (sob gene) were examined by PCR which has known as a big problem because of their temperature resistance. Hence, PCR was performed on isolated 4 staphylococci. The all 4 isolated Staphylococcus aureus have 477 bp of seb gene. Antibiotics susceptibility test was completed on PCR detected strains. All strains were fully resistance to ampicillin and penicillin. The drinking water of A place has resistance to oxacilline, therefore this strain turned out to be MRSA (Methicilline Resistant Staphylococcus Aureus).

• International Journal of Air-Conditioning and Refrigeration
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• v.10 no.1
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• pp.31-39
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• 2002

Microencapsulated pcm (MPCM) particles are mixed with distilled water and utilized to evaluate its characteristics and performance as a thermal storage medium transporting heat. For the present study, tetradecane ($C_14$$H_30$, $T_m$=5.5$^{\circ}C$) is capsulated in the core, coated with the melamine for their surface. The size of particles is well-controlled under 10$\mu$m in the process of in-situ polymerization with melamine-formaldehyde resin. For the experiment, the concentractions of slurries are prepared for 20 wt%, 30 wt%, and 40 wt%. The results are compared with those of water and 100% tetradecane oil. The pure water and tetradecane start solidifying within 20 minutes after introducing cooling water into the thermal storage tank whose flow rates are varied by 125 cc/min, 250 cc/min, and 500 cc/min. However, MPCM slurries are required relatively longer period of time for their phase change than pure phase change materials. That is, the entrained MPCM particles restrict their heat transfer in terms of natural convection and conduction to them.

• Hwankyungkyoyuk
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• v.24 no.2
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• pp.1-20
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• 2011

The purpose of this research is to apply and evaluate the Water Environmental Education Program Using Streams(WEES) to pre-service teachers. WEES is developed to help the teachers increase their professionalism of incorporating a local environment into their inquiry teaching. The subjects of the study include the juniors of the Environmental Education Major at the Korea National University of Education. For the purpose this study, educational criticism about WEES was performed. The subject students were observed throughout the program application, after which a survey and in-depth interviews were carried out. As a result, the implementation elements and content organization of the WEES were found to be implemented in the application process in a satisfying level. In the content organization of the program, the preliminary preparation, visual assessment, and inquiry planning were organically connected with each other for inquiry purposes. The Intrinsic value of environmental education was also demonstrated in the implementation elements and content organization. Overall, the stream turned out to have a great value of environmental education and a potential as a place and material for environmental education. The great significance of the study can be found in that WEES took into account not only the characteristics of the ENVISION based on the watershed concept, but also the situations of Korea's environmental education and exploration from the perspective of environmental studies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.417-428
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• 2018

The purpose of this study is to raise the necessity of ensuring sustainability of water infrastructures in economic, social and environmental sectors by using index that evaluates the sustainability centering on water supply and wastewater utilities. This study identified sub-indexes that should be stressed among different indexes in economic, social and environmental aspects and those indexes were compared by each clusters of cities. The principal component analysis was used to calculate the weights of the sub-indexes, and the k-mean cluster analysis was conducted to classify the clusters. As a result of the weighting analysis, financial independence, service revenue ratio, subsidy ratio, population coverage ratio, deterioration, stream/river ecosystem health and river water quality were found to be the major variables in assessing sustainability. Cities were then classified into two groups using the k-mean cluster analysis. The overall sustainability scored high in the economic sector was relatively satisfactory, but it was necessary to improve the environmental sustainability. The group with relatively good environmental sustainability showed low score in the overall sustainability and required improvements in the economic sector.

• Journal of Families and Better Life
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• v.16 no.4
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• pp.69-82
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• 1998

As a way to serve housing information providing on internet will be a useful method in the near future in Korea. This study was planned to review the housing information on internet network which provided by U. S. .University CES(cooperative extension service) Comparative analysis was used as a Research method in terms of contents and items about housing information on internet provided by U. S. university CES during two weeks each in August 1997 and July 1998. Findings are as follows; Universities providing housing information and information items had been remarkably increased during one year since August 1997. Most of housing informations except one university CES were free to use in 1997 but three university CES among 12 universities showed only the title of items with charge amounts in 1998. Informations about 'Housing Management' and 'Environment' items were the large parts of the housing information in 1997. In 1998. 'Environment' items were remarkably increased. Items bout insects and mildew removing were large portion of the 'Housing Management'. Items about energy saving water and air quality were large portion of the 'Environment' These findings will be useful to develop items of housing information on internet network with Korean language which should be compensated by the survey research.

• Economic and Environmental Geology
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• v.41 no.5
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• pp.497-507
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• 2008

This study identified and quantified the hidden flows for steel and iron production in Korea using MIPS (Material Input per Service) methodology. In order to estimate the input orientated impact on the environment caused by the manufacture or services of a product, MIPS indicates the quantity of resources used for this product or service. In 2005, 71 million tons of raw materials were used to produce $17.6 million of added value and 4.8 thousand tons of finished steel. The amount of natural resources extracted from natural environments for the purpose of steel production was 245 million tons of TMR(Total Material Requirement), 1524 million tons of water, and 34 million tons of air. The material intensities for steel production by natural inputs (raw materials and energy) was 4.3 ton/ton of TMR, 28 ton/ton of water, and 0.5 ton/ton of air.