• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.6
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• pp.411-419
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• 1999

It has been well recognized that a long term service at elevated temperature of $350^{\circ}C{\sim}550^{\circ}C$ induces embrittlement damage due to carbide precipitation and/or P, Sb and Sn segregation at grain boundaries and thereby deteriorates the grain boundary strength of heat resisting components in the energy-related plants. Therefore, it is very important to assess quantitatively the extent of embrittlement damage of heat resisting components to secure the reliable and efficient service condition and to prevent brittle failure in service. However, because fracture tests are limited in size and number of specimen obtained from the structural components, nondestructive test method is required. In this study, the optimum electrochemical parameters are investigated and discussed to evaluate nondestructive embrittlement damage for aged 2.25Cr-1Mo steels by means of electrochemical polarization test method (ECPTM) in proper corrosive environment. In addition, the electrochemical test results are compared with embrittlement degree evaluated by semi-nondestructive SP test.

• Journal of Korea Water Resources Association
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• v.33 no.4
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• pp.447-459
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• 2000

Since the development of water resources is getting more difficult than ever before because of human-sociological condition, it would be necessary to develop a practically applicable technique for the management of water resources based on demand-side concept that could reduce unusable release for more effective and appropriate allocation of limited water resources. The objective of the study is to develop an optimal reservoir system operation model for water supply and energy augmentation by the combination of water budget analysis method in downstream area by MIP technique. The applicable study of the developed model was carried out and water supply capability of Nakdong river basin was re-evaluated by the developed model. The model has been found successful to guarantee appropriate water supply to the basin by means of deficit-supply management method and also turned out to be more practical tool for an optimal reservoir system operation model than other existing models.

• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.335-345
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• 2001

The objective of this research is to analyze the hydrological environment changes in Daechung Dam Basin due to the global warming. GCM simulation results are used to predict the possible changes in precipitation and temperature. The changes of potential evapotranspiration, soil moisture and runoff due to the changes of precipitation and temperature are analyzed using a conceptual water balance model. From the simulation results using the water balance model for lx$CO_2$ and 2x$CO_2$ situations, it has been found that the runoff would decrease in Winter, but increase in Summer and Fall due to the global warming. Therefore, it is predicted that the frequency of drought and flood occurrences in Daechung Dam Basin would be increased in 2x$CO_2$ condition.

• Korean Journal of Medicinal Crop Science
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• v.9 no.4
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• pp.265-268
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• 2001

This experiment was conducted to investigate the effects of temperature, light, seed harvesting time, storage temperature, and period on its germination of Astragalus membranaceus. Optimum germination temperature was ${20{\sim}25^{\circ}C}$ and it was found to be light insensitive seed. The germination rates were not significantly different between 1-year and 2-year old plants, and seed harvesting times. Seeds stored at such cold temperatures as ${-4^{\circ}C\;and\;-20^{\circ}C}$ for 15 months showed over 80% in germination rate at the 6th day after placement. On the other hand, low germination rate of 60% at the 11th day was observed from the seeds stored at $4^{\circ}$ and room temperature.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.879-890
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• 2017

The US Pavement Design method (AASHTO) and HDM-4, a road pavement maintenance decision system, are not suitable for domestic pavement design, construction and maintenance. KPRP(Korea Pavement Research Program) has been developed to reflect Korea's environmental conditions and vehicle characteristics, thereby, extending pavement life. The main objective of this study is to select the best alternative through Life Cycle Cost $CO_2$ (LCCC) calculations among three representative maintenance strategies using KPRP design software since the environment cost resulting from the extended pavement life will also differ. The analysis of this study illustrates that cumulative carbon emissions for 40 years in alternative 2 (Cutting and Overlaying at Year 30) is the lowest option among them, and the basic cost of $CO_2$ emission by various road maintenance and repair work can be used for suggesting an optimal maintenance strategy for highway agency.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.2
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• pp.211-221
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• 2018

Objectives: The purpose of this study was to identify work-related risk factors associated with upper extremity symptoms among construction workers using the fourth Korean Working Condition Survey(KWCS). Methods: Subjects were 2,724 construction workers selected from 50,007 respondents in the 2014 KWCS. The presence or absence of upper extremity symptoms and work-related risk factors, including individual, physical, and psychosocial factors, were used as variables. A multiple logistic regression analysis was performed in order to evaluate the relationship of the upper extremity symptoms with work-related risk factors. Results: Upper extremity symptoms were significantly associated with: employment type(OR: 1.57, 95% CI: 1.18~2.09); job satisfaction(OR: 2.06, 95% CI: 1.33~3.18); verbal abuse(OR: 2.06, 95% CI: 1.33~3.18); tiring or painful posture(OR: 2.33, 95% CI: 1.73~3.15); carrying or moving heavy loads(OR: 1.68, 95% CI: 1.23~2.24); repetitive hand or arm movement(OR: 1.42, 95% CI: 1.06~1.91) Conclusions: In order to prevent the upper extremity musculoskeletal disease in the construction industry, it is necessary to stabilize employment, enhance job satisfaction, and eliminate violence in the workplace and improve physical work environment.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.13 no.1
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• pp.48-53
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• 2013

Tyrosinemia I (fumarylacetoacetate hydrolase deficiency) is an autosomal recessive inborn error of tyrosine metabolism that produces liver failure in infancy or a more chronic course of liver disease with cirrhosis, often complicated by hepatocellular carcinoma in childhood or early adolescence. We studied a 37-year-old woman with tyrosinemia I whose severe liver disease in infancy and rickets during childhood were resolved with dietary therapy. From 14 years of age, she resumed unrestricted diet with the continued presence of the biochemical features of tyrosinemia, yet maintained normal liver function. In adult years, she accumulated only a small amount of succinylacetone. Despite this evolution to a mild biochemical and clinical phenotype, she eventually developed hepatocellular carcinoma. Her fumarylacetoacetate hydrolase genotype consists of a splice mutation, IVS6-1G>T, and a novel missense mutation, p.Q279R. Studies of resected liver revealed the absence of hydrolytic activity and immunological expression of fumarylacetoacetate hydrolase in tumour. In the non-tumoral areas, however, 53% of normal hydrolytic activity and immunologically present fumarylacetoacetate hydrolase were found. This case demonstrates the high risk of liver cancer in tyrosinemia I even in a seemingly favorable biological environment. In this study of tyrosinemia I, Case 2 with negative succinylacetone accumulation and the recovery of acute liver failure was compared with Case 1. Diet restriction and NTBC treatment are crucial to prevent hepatocellular carcinoma until liver transplant can take place and cure the condition. Further studies are needed to examine cases where liver cancer did not result despite clinical symptoms/signs of tyrosinemia type I.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.607-617
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• 2009

With the promotion of the u-City project in recent years, the need for the systematic and efficient management of ground and underground facilities comprising the urban infrastructure has been increased. Considering that the diverse services provided in the u-City are closely related to the physical environment of the city itself, including its location and condition, the core of such management must be to continuously maintain these facilities in a normal state, based on accurate data collection from the facilities. This paper discusses a method of collecting the sensor and the object data that are needed to accurately understand the state of the underground facilities, and presents a plan to build an Underground Facility Management System on this basis. This plan is then verified using a scenario test performed by a prototype system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.629-635
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• 2009

Collapses of cutting area have frequently occurred due to heavy rainfall caused by the recent unusual weather patterns. Collapses of cutting area have the most crucial influence on the damaged property and casualties. Therefore, formulating and preparing an effective measures and control system is urgent. For this reason, in this study, we researched formation investigation method of location-based cutting area for an efficient management of cutting area. We conducted comparative and analytic research on the hand GPS method and DGPS method which is GPS augmentation system, using SBAS signals. The results of the research showed that there was difficult in discerning the accurate shape of cutting area when the existing method was used; however, the detecting the shape of four sides and accurate location was possible when DGPS was used. Consequently, it is possible to establish a preventive measures for cutting area, which considers the condition of the surrounding environment of cutting area because the polygon based management of incision cliff is attainable, apart from the existing control point based approach.

• Journal of Microbiology
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• v.41 no.2
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• pp.89-94
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• 2003

Bacterial strain No. P08 isolated from wastewater at the Cheongju industrial complex was found to be capable of degrading 4-chlorobenzoate under aerobic condition. P08 was identified as Comamonas sp. from its cellular fatty acid composition and 16S rDNA sequence. The fcb genes, responsible for the hydrolytic dechlorination of 4-chlorobenzoate, were cloned from the plasmid pJJl of Comamonas sp. P08. The fcb gene cluster of comamonas sp. PO8 was organized in the order fcbB-fcbA-fcbTl-fcbT2-fcbT3-fcbC. This organization of the fcb genes was very similar to that of the fcb genes carried on the chromosomal DNA of pseudomonas sp. DJ-12. However, it differed from the fcbA-fcbB -fcbC ordering of Arthrobacter sp. SU. The nucleotide sequences of the fcbABC genes of strain P08 showed 98% and 53% identities to those of Pseudomonas sp. DJ-12 and Arthrobacter sp. SU, respectively. This suggests that the fcb genes might have been derived from Pseudomonas sp. DJ-12 to form plasmid pJSl in Comamonas sp. P08, or that the fcb genes in strain DJ-12 were transposed from Comamonas sp. P08 plasmid.