• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.73-79
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• 2015

In consideration of current circumstances which management activities for safety performance on construction sites are mostly controlled by safety personnel, it is necessary to maintain qualified safety personnel those who are experienced and have adequate ability. This is a major factor in order to prevent any of work related incident in the construction site. However, the existing standard which enforces certain number of safety personnel in the construction site aligning with respective contract amount could lead to difficulties for proactive safety management. So, it is required to get improvement on the existing standard. In nominating the proper number of safety personnel, it would be more efficient to consider the level of risk for characteristic of work itself and the total number of manpower mobilized in respective construction work, rather than to follow the existing standard of manpower ratio as per the contract amount. Hence, this study aims to propose several plans which enable to improve the existing standard for assignment of safety personnel on construction sites.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.34-42
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• 2009

There are many accident causes related to even an accident. As well four(4) stepped causes of one accident at construction sites are analyzed in the study. First, eleven(11) cause factors are set up at each step such as policy level, management, indirect, direct level which are discussed and determined by field experts with 15year experience or more. Therefore, one direct cause occurred in construction site can be connected to the previous cause than in direct and management, and policy problem of previous management. These questionnaires results are analyzed with three different methods such as weighing level by Delphi technique, correlation analysis, critical pass method. Three different methods show their characteristic to see which subcontract work is more dangerous or not. Subcontract or at a construction site can be use the above three different cases as they need at their site in order to make more effective countermeasures.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.648-663
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• 2012

With recent attempts to improve quality and productivity, the prefabrication manufacturing system has been occupying an increasing share of the construction area. To minimize site work, material is more frequently being produced and partially assembled at a plant, and then installed at a site. For this reason, the production process is being divided and the materials are being delivered to the site after passing through multiple plants. With these changes in the production process, the materials delivery plan is becoming an important management point. In particular, as road transportation using trucks has a 71 percent share of the domestic transportation market, selecting the proper transportation path is important when delivering materials and equipment to a site. But the management system at the project design phase to calculate the delivery cost by considering the production process of the pre-fab material and the $CO_2$ emission at the material delivery phase is currently lacking. This study suggests a process design model for assembly production of the pre-fab material and transportation logistics based on carbon emission. The suggested model can be helpful to optimize the location of the intermediate plant. It is expected to be utilized as a basic model at the project plan and design phase when subcontractors make decisions on items such as materials procurement, selecting the production method, and choosing the location of the assembly plant.

• Preventive Nutrition and Food Science
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• v.6 no.1
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• pp.79-81
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• 2001

Deoxynucleoside kinases exist as heterodimeric pairs specific for deoxyadenosine/deoxyguanosine kinase (dAK/dGK) and deoxyadenosine/deoxycytidine kinase (dAK/dCK). The aspartic acid-84 in dGK was mutated to alanine, asparagine and glutamic acid by site-directed mutagenesis. The mutation resulted in a drastic decease in dGK activity compared to the unmodified cloned enzyme while it increased production of dAK activity. The mutated dak/dgk genes, which synthesize tandem deoxyadenosine/deoxyguanosine kinase, were inserted back to the Lactobacillus acidophilus and Lactococcus lactis by electroporation to determine the effect of site-directed mutation of he enzymes on the microbial growth. However, no significant change was observed in cell growth and lactic acid production between wild type and mutant lactic acid bacteria.

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.169-182
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• 2017

Iron and nitrogen codoped carbon (Fe-N/C) catalysts have emerged as one of the most promising replacements for state-of-the-art platinum-based electrocatalysts for oxygen reduction reaction (ORR) in polymer electrolyte fuel cells. During the last decade, significant progress has been achieved in Fe-N/C catalysts in terms of ORR activity improvement and active site identification. In this review, we focus on recent efforts towards advancing our understanding of the structure of active sites in Fe-N/C catalysts. We summarize the spectroscopic and electrochemical methods that are used to analyze active site structure in Fe-N/C catalysts, and the relationship between active site structure and ORR activity in these catalysts. We provide an overview of recently reported synthetic strategies that can generate active sites in Fe-N/C catalysts preferentially. We then discuss newly suggested active sites in Fe-N/C catalysts. Finally, we conclude this review with a brief future outlook.

• BMB Reports
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• v.43 no.6
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• pp.419-426
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• 2010

Aeromonas hydrophila is a bacterial pathogen that infects a large number of eukaryotes, including humans. The UDP-galactose 4'-epimerase (GalE) catalyzes interconversion of UDP-galactose to UDP-glucose and plays a key role in lipopolysaccharide biosynthesis. This makes it an important virulence determinant, and therefore a potential drug target. Our earlier studies revealed that unlike other GalEs, GalE of A. hydrophila exists as a monomer. This uniqueness necessitated elucidation of its structure and active site. Chemical modification of the 6xHis-rGalE demonstrated the role of histidine residue in catalysis and that it did not constitute the substrate binding pocket. Loss of the 6xHis-rGalE activity and coenzyme fluorescence with thiol modifying reagents established the role of two distinct vicinal thiols in catalysis. Chemical modification studies revealed arginine to be essential for catalysis. Site-directed mutagenesis indicated Tyr149 and Lys153 to be involved in catalysis. Use of glycerol as a cosolvent enhanced the GalE thermostability significantly.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.51-59
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• 2004

The evaluation of shear modulus is very important in various fields of civil engineering. In this paper, the site characterization method using HWAW method is applied to determine shear wave velocity profile of two test sites in order to verify the field applicability of HWAW method. Shear wave velocity profiles by HWAW method are compared with shear wave velocity profiles by SASW test and PS-Suspension Logging test. Through field applications, it is shown that HWAW method can minimize the effect of noise and lateral non-homogeneity of the site and determine detailed local shear wave velocity profile of site.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.286-290
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• 2011

This paper introduces the optimum macro-siting of a potential site for an offshore wind farm around Jeju Island using the RDAPS sea wind model. The statistical model was developed by analyzing the sea wind data from RDAPS model, and the meso-scale digital wind map was prepared. To develop the high resolution spatial calibration model, Artificial Neural Network(ANN) models were used to construct the wind and bathymetric maps. Accuracy and consistency of wind/bathymetric spatial calibration models were obtained using analysis of variance. The optimization problem was defined to maximize the energy density satisfying the criteria of maximum water depth and maximum distance from the coastline. The candidate site was selected through Genetic Algorithm(GA). From the results, it is possible to predict roughly a candidate site location for the installation of the offshore wind jam, and to evaluate the wind resources of the proposed site.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.2
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• pp.37-42
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• 2011

Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional Cooling + reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 50% less equivalent energy than the conventional system. The on-site performance test of a prototype shows that the coefficient of performance(COP) of the DOA system is 37% higher than the conventional system.

• Nuclear Engineering and Technology
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• v.36 no.3
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• pp.263-275
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• 2004

For the safe management of nuclear facilities, including a radioactive waste repository, data about the facility site and the surrounding environment must be collected and managed systematically. This is particularly true for a radwaste repository, which has to be institutionally controlled for a long period after closure. The objectives of this study are (1) to establish a systematical management plan for information about a radwaste repository site and its environment, and (2) to design a database management program for this information, based on the Relative Database Management System (RDBMS). The spatial data are designed by the geodatabase, which is a new object, based on the RDBMS, to manage spatial information related to the database. To meet this requirement, a new program called 'Site Information and Total Environmental data management System (SITES)' is being developed. The scope that produced from the first step of the present study for development of the SITES is introduced. The database is designed to combine spatial and attribute data, and is designed for the establishment of the Geographic Information System (GIS). The hardware and software systems are designed with consideration given to the total data management of the items within the radioactive environment.