• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5350-5355
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• 2012

Human tyrosinase (hTyr) catalyzes the first and rate limiting step in the biosynthesis of a skin color determinant, melanin. Although a number of cosmetic companies have tried to develop hTyr inhibitors for several decades, absence of 3D structure of hTyr make it impossible to design or screen inhibitors by structure-based approach. Therefore, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from Bacillus megaterium to provide structural information and to search new hit compounds from database. Our model revealed that two copper atoms of active site located deep inside and were coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Substrate binding site had narrow funnel like shape and its entrance was wide and exposed to solvent. In addition, hTyr-tyrosine and hTyr-kojic acid, a well-known inhibitor, complexes were modeled with the guide of solvent accessible surface generated by in-house software. Our model demonstrated that only phenol group or its analogs could fill the binding site near the nuclear copper center, because inside of binding site had narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogenic agents.

• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.167-189
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• 1992

The most difficult problem one faces in estimating North Korea's GNP is the lack of basic national income data. In addition, there is no appropriate foreign exchange rate available to convert North Korea's GNP to dollar values. The physical indicators method is particularly useful in estimating North Korean GNP because it requires only a modest amount of data and obtains dollar GNP directly by applying a relationship between physical indicators and GNP, which is estimated from reference countries, to physical indicators of North Korea. The estimated result of North Korean GNP in 1990 is 27.1 billion dollars and per capita GNP 1,268 dollars. The trade participation ratio (Trade/GNP) implied by the GNP estimate was plausible and so was the ratio of fiscal expenditure to GNP. This paper examined the physical indicators method's logic, the quality of the North Korean data that was used in the estimation, and the plausibility of estimation result. Relatively simple data requirement, comparative ease of computation and plausible estimation results suggest that use of physical indicators method could enhance the reliability of North Korean GNP estimate.

• Sleep Medicine and Psychophysiology
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• v.26 no.2
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• pp.86-103
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• 2019

Objectives: The objective of this study was to develop evidence- and consensus-based clinical safety usage guidelines for sedative hypnotics using the Delphi technique. Methods: A group of 15 sleep experts from Korean Academy of Sleep Medicine were chosen for this study comprising a three-round web-based Delphi survey. The first round survey was composed of 39 questions to identify problems with sedative hypnotics usage in Korean clinical practice and the result roughly outlined what should be included in the guidelines. The second round survey was composed of 21 questions to collect specific opinions of experts on clinically important issues in prescribing sedative hypnotics, and its result provided the basis for the guidelines. A third round survey aimed to evaluate the reliability and validity of the established guidelines. Results: In the third round, all 17 items showed a median of 4 or more, with an average of 4.12 and a standard deviation of 0.32. Thus we present safety usage guidelines with 13 propositions for prescription, maintenance, and withdrawal of sedative hypnotics. Conclusion: The safety usage guidelines on sedative hypnotics developed from this study could lead to safe and effective prescription of hypnotics in clinical practice, especially for the non-experts in sleep medicine. Furthermore, the guidelines will help to improve the quality of insomnia treatment by contributing to the establishment of a safe regime for sedative hypnotics without excessive use of drugs.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.275-282
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• 2006

Recently, Fiber Reinforced Polymers(FRP) has been emerged as an alternative material to solve the corrosion of steel reinforcement in reinforced concrete structures. FRP exhibits higher specific strength and lower weight compared to steel reinforcement. Moreover, good resistance to corrosion of the FRP may be useful in aggressive environments causing deterioration such as chloride environment. However, causes for higher initial cost of FRP than that of steel, little information on the long-term behavior of FRP, and brittle failure make the efforts to apply FRP in civil structures slow. Glass fiber among the fibers used to manufacture FRP can be seen as the most beneficial material with regard to initial costs. But its low elastic modulus, which attains barely a quarter of steel, nay thus lead to excessive deflections when used as reinforcement for flexural members. This research was carried out on the tensile properties of hybrid rods made with glass and carbon fibers to improve those of FRP rod made with glass fiber. Parameters were resin type and the arrangement of glass and carbon fibers. The tensile properties of hybrid rods were compared with those of rods manufactured with only glass or carbon fibers. The results indicated that the tensile properties of hybrid rod were good when the carbon fiber was arranged in the core.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.637-645
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• 2011

It is well known that high strength concrete with compressive strength higher than 50 MPa shows severe material and structural damages under fire due to spalling. To understand degradation of structural capacity of fire damaged high strength concrete structures, not only thermo-mechanical behavior needs to be defined, but also structural behavior of high strength concrete member under high temperature needs to be investigated. In this study, structural tests are performed by applying axial loads on high strength concrete columns exposed at elevated temperatures for assigned amount of time. The tested columns are prepared to have different concrete strength and polypropylene fiber percentage. The test results show that structural capacity of the columns decreased with increased compressive strength of concrete under same heating condition. Especially, it is interesting to note that high strength concrete columns with polypropylene fiber for spalling proof did not improve structural capacity compared to the columns without polypropylene fiber. The findings from the test are able to improve fire proof design of high strength concrete structural members and predicting structural performance of fire damaged structural members.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.10
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• pp.1145-1156
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• 2015

There is a shortage of mobile application systems readily applicable to the field of crop cultivation in relation to diseases and insect pests directly connected to the quality of crops. Most of system have been devoted to diseases and insect pests that would offer full predictions and basic information about diseases and insect pests currently. But for lack of the instant diagnostic functions seriously and the field of crop cultivation, we design and implement a crop cultivation field-oriented smart diseases and insect pests information retrieval system based on mobile for u-Farm. The proposed system had such advantages as providing information about diseases and insect pests in the field of crop cultivation and allowing the users to check the information with their smart-phones real-time based on the Lucene, a search library useful for the specialized analysis of images, and JSON data structure. And it was designed based on object-oriented modeling to increase its expandability and reusability. It was capable of search based on such image characteristic information as colors as well as the meta-information of crops and meta-information-based texts. The system was full of great merits including the implementation of u-Farm, the real-time check, and management of crop yields and diseases and insect pests by both the farmers and cultivation field managers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.289-301
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• 2017

As earthquakes have frequently happened all over the world, huge losses of human life and property have occurred. Therefore, retrofitting and strengthen technologies of non-seismically designed structures in Korea are urgent. Also, there has been a growing interest about seismic retrofitting, where researches on the topic have been actively pursued in Korea. The study results showed that ductility inducing retrofitting method is more superior stiffness inducing method. In Japan, Super Reinforcement with Flexibility (SRF) was introduced. Therefore, in this study, seismic performance evaluation was performed through pseudo dynamic test and uniaxial compression test for RC column retrofitted by PolyUrea for ductility inducing retrofitting material. Uniaxial compression test results showed that strength of all specimens retrofitted by PolyUrea was higher than that of RC specimens. Also, all specimens retrofitted by PolyUrea also showed ductile fracture behavior. In pseudo dynamic test, by appling real earthquake record, the seismic behavior of RC column reinforced by PolyUrea was evaluated through relative displacement, reinforcement strain, displacement ductility, and dissipation energy. The results showed that PolyUrea helped to enhance seismic performance of RC columns.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.28-34
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• 2018

Purpose With regard to the use of radioiodine in domestic medical institution, the case of exceeding the allowance of nuclear safety Act about radioactive concentration in drainage was found. Through understanding the cause of exceeding case and analyzing radioactive concentration in drainage, evaluating the relationship of the public waters in surroundings and usefulness. Materials and Methods From November 1, 2014 to April 30th, 2015, the research is aiming at domestic twenty hospitals for six months. By using a HPGe gamma-ray spectrometer(Canberra DSA-1000) and GENIE-2000 Analysis software for comparative analysis, measuring a radioactive concentration of radioiodine in drainage. Consequently, we confirm the excess of radioactive concentration of radioiodine in seven medical institutions. Results Conducting a survey of twenty hospitals and average radioactive concentration of radioiodine in drainage appears $42,100Bq/m^3$. The features of domestic hospitals where show a high radioactive concentration are a number of medical treatment patient when using radioactive iodine and the absence of private rest room. During I-131 whole body scan, the pretreatment procedure of urinating is considered emission of residual Iodine. In public waters, the cause of exceeding detect on radioactive concentration in drainage suppose a diagnostic radioactive iodine. Conclusion We confirm the importance of enhanced education, providing a safety control instructions and installing a private rest rooms for patients who injected a low capacity radioiodine. Also, constructing institutional and legal management system is considered about the Emission management standard in drainage.

• Korean Journal of Construction Engineering and Management
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• v.5 no.1 s.17
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• pp.71-79
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• 2004

In the stage of feasibility study of urban rehabilitation projects, the precise forecast of physical and environmental changes has great influence on the further transaction of the projects. However, various important decision makings are made by the experience and intuition of the person-in-charge in practice without the process and method for systematic and quantitative analysis. In spite of various qualitative influent factors on the projects, the feasibility studies are made by the result of economic analysis only, which often lead the projects to the crucial deficit. The main reasons of such a mal-functional transaction are due to the absence of the reasonal procedure of feasibility study and decision making reflecting the characteristics of urban rehabilitation projects. The objective of this paper is to propose feasibility study processes and decision making methods in relation to various influent factors on urban rehabilitation projects in the initial stage. The goal and process of every analysis stage and the pertinent factors and decision makings are analyzed and proposed through the survey of current research, a case study, interview with the professionals. The processes and methods are well applied to improve current problems of feasibility study of urban rehabilitation projects. In addition, the establishment of the analysis goal at three principal stage and a series of reasonable decision makings with pertinent factors to each stage will lead the project to more successful result than ever.

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.269-280
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• 1998

Recently, application of composite materials such as fiber reinforced concretes(FRCs) and fiber reinforced plastics(FRPs) in conjunction with conventional structural components has become one of the main research areas. A proper use of advanced composite materials requires understanding their resistance mechanism and failure mode when they are applied to structures or their components. Particular considerations are given in this research to develop an analytical model which can predict the nonlinear flexural responses of bonded and unbonded prestressed concrete beams possibly having layers of different cementitious composite matrices in a section and/or FRP tendons. The block concept is used, which can be regarded as an intermediate modeling method between the couple method with one block and the layered method with multiply sliced layers in a section. In order to find a particular deflection point of a beam under load, solutions to the 2N-variables are found numerically by using approximate N-force equilibrium equations and N-moment equilibirum equations. The model is shown to successfully predict the flexual behavior of variously reinforced bonded and unbonded prestressed concrete beams. The model is also successful in simulating a gradually increasing load after sudden drop inload resistance due to fracture of one or more FRP tendons. This feature is useful in tracing the overall load-deflection response of a beam prestressed with brittle FRP tendons.