• Korean Journal of Materials Research
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• v.25 no.2
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• pp.90-94
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• 2015

We prepared 8 samples of non-silver and silver-added master alloys containing silicon to confirm the existence of nickel-silicides. We then prepared products made of 14K and 18K white gold by using the prepared master alloys containing 0.25, 0.35, and 0.50 wt% silicon to check for nickel release. We then employed the EN 1811 testing standard to investigate the nickel release of the white gold products, and we also confirmed the color of the white gold products with an UV-VIS-NIR-color meter. We observed $NiSi_x$ residue in all master alloys containing more than 0.50 wt% Si with EDS-nitric acid etching. For the white gold products, we could not confirm the existence of $NiSi_x$ through XRD after aqua-regia etching. In the EN 1811 test, only the white gold products with 0.25 wt% silicon master alloys successfully passed the nickel release regulations. Moreover, we confirmed that our white gold products showed excellent Lab indices as compared to those of commercial white gold ones, and the silver-added master alloys offered a larger L index. Our results indicate that employing 0.25 wt% silicon master alloys might be suitable for white gold products without nickel-silicide defects and nickel release problems.

• Korean Journal of Construction Engineering and Management
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• v.6 no.2 s.24
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• pp.102-110
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• 2005

After the IMF bailout, the Environment of Domestic Construction Industry had changed dramatically. Before the IMF, Domestic Construction Firms are secured by the government regulations and some traditional practices. However, due to the following reasons: a decrease in public works, an increase in uncertainty of market prediction, the change of bid system, and increase in construction firms, recently the competition among construction firms has became keen. Under the serious competition, in order that medium-size construction firms survive in the construction market, it is need to establish the strategy that could increase productivity. In order to establish the strategy, firstly, construction firms should set up an appraisal standard of construction firms. Consequently, This study will introduce companies' objective appraisal in domestic construction market as well as basal data for setting-up strategy through adaptation industry structure analysis of business administration for strategic group analysis and a company which has lagged behind competitive power among the competitive companies can choose a target strategic group which should be pursued it in the future through being classified according to a group taken analogical strategy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6655-6665
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• 2015

Due to tightened environmental regulations on halogen type flame retardants, the portions of those based on phosphorous compounds that are non-halogen type is rising. When producing functional film, the physical and thermal properties become distinctly different depending on the amount of Red-phosphorus(RP) addition which causes flame resistance. The physical properties of resin fall in big scale when too much flame retardants are added, and it is hard to be applied to functional films such as shrink or anticorrosive film. The purpose of this research is to study the effects on mechanical, physical, and other properties of RP-LDPE films by changing the RP-MB contents. The LDPE film used for this study was produced through blow-type injection molding. The flame resistance was VTM-0, and the tear resistance showed inverse trends of MD and TD. Contraction percentage showed no relationship with the amount of RP content, but the anti-corrosive property showed 0.05 % better result than the national anti-corrosion shrink film reliability standard.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.157-164
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• 2016

This paper aims to create standard forms of MRV plan and report, used when policy funds are applied in accordance with ESCO regulations, when energy savings are measured (the savings would be generated as energy users and ESCOs signed the contract of guarantee for energy savings, and energy saving facilities are installed following the contract). To fully reflect the goals and effects of the installation of energy saving facilities, MRV plans and reports will be completed for the purposes of measuring, verifying, and reporting if the goals of energy savings have been achieved successfully. In this paper, the forms of MRV plans and reports were developed with the detailed descriptions for each form and instructions of completion. Based on the developed forms of MRV plans and reports, future studies need to developed guidelines to explain how to fill out these forms considering the application cases by ESCO technology and facility.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.21-33
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• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.3
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• pp.57-64
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• 2009

Field surveys for the digital map being constructed is being conducted using various work guide books based on the digital mapping internal rule. However, a modification of a rule used for paper map construction is being used for the digital mapping rule, which is causing many problems with the quality of the digital map. Therefore, to construct a high-quality digital map, general standards related to conducting field surveys need to be reviewed, and it's extremely important to construct an accurate digital map based on this. Accordingly, in this study, problems related to conducting field surveys for the construction of the digital map are analyzed in order to establish more suitable field survey standards for constructing an accurate digital map. To this end, work regulations related to construction of a digital map were analyzed, and attribute and field survey data were compared to those of a previously-constructed digital map for analysis. By reflecting opinions of field surveyors and related experts to the results of the analysis, more suitable field survey standards for constructing the digital map were presented.

• Korean Journal of Construction Engineering and Management
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• v.2 no.1 s.5
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• pp.57-67
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• 2001

In 1999, a residence stock amounts to 11 million units and apartment housing holds 57.6 percent of the residence stock. Without proper remodeling for apartment housing, a significant portion of them would be expected to be demolished shorter than their life-time due to socioeconomic reasons. Apartment housing is maintained depending on government regulations such as 'Housing Construction Promotion Code' and 'Apartment Housing Maintenance Ordinance'. However, there are many problems with implementation of them. In order to solve the problems, we focus on the remodeling system that includes Maintenance of Apartment Housing, Finance and Taxation, Special Repair Appropriation Budget, Resource Quality and Standard Plan, and Remodeling associated with the code. And this study, which being compared with the foreign remodeling system, presents the improvement scheme of system for apartment housing remodeling. This study aims to promote remodeling apartment housing and provide the suitable scheme for remodeling activities.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.597-603
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• 2018

This Study investigates the Structural Integrity of Boats for Divers, given increased demands for Underwater and Recreational use. We conducted research on a Small Catamaran with a Moon Pool in the center of the Hull, using the Finite Element Method to calculate allowable stress based on the ISO Rule. We computed the coefficients defined in ISO 12215-5 and TC118.1225-7, and determined the suitability of using the ISO Standard and Allowable Stress Design method (ASD) by applying Longitudinal Bending Moment, Torsional moment, and Bottom Slamming Load. We also applied the Ultimate Strength Design Method (LFRD) using Finite Element Analysis (FEA). As a Result of this Research, it was found that ships with a Moon Pool do have Structural Integrity according to their Design in accordance with ISO and KR Regulations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.604-610
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• 2018

Recently, due to the rapid growth of the leisure industry, demand for small-scale flotation and mooring pontoon platforms has been increasing rapidly. Standard rules for the design and structural safety of such structures have become necessary. This paper provides criteria that can be referenced when designing pontoon platforms, and also introduces structural safety evaluation procedures. In this study, the structural safety and stability of a 15-meter pontoon platform were investigated through structural design and finite element analysis. For platforms of less than 10 meters in length, a simple structural calculation can be used, but for platforms over 10 meters, a detailed structural strength review must be considered to meet safety guidelines defined in existing regulations. The structural strength of the initial design was examined and its structural safety was verified. For future research, it is an evaluative system was developed that can be used to examine the various loading conditions during design.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.135-141
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• 2015

According to the statistics, occupational fatal injuries by mobile cranes were about 12 per year in whole industrial. Mobile cranes are widely used in various parts of industries to improve the efficiency of the work. However considerable number of fatal injuries happen each year during the operation of the machines. In this study, the current regulations to be adequate in industrial site have to be renew in order to prevent the fatal injuries by mobile cranes. Fatal injury analyses were conducted with several accident cases by the mobile cranes. For each accident, the causes of the injuries were examined and proper safety measures were proposed. In this study, the mobile crane showed a high fatality rate in industrial accidents and no detailed cause analysis of fatal accidents was conducted in terms of unsafe acts or conditions. This study proposed a revision of the standard guideline as an accident prevention measures through in-depth analysis of fatal accidents. First, among the mainly five machines caused the accidents, mobile crane was higher for the second showed 0.6% for number of fatalities compared to number of mobil cranes and for the third showed 11% for number of fatalities compared to number of injuries. Second, main cause of cognitive engineering agenda was visibility, responsibility, affordance. As the measures to prevent accidents before starting operation, alternative revision for the fool proof including visibility, responsibility, affordance etc. for the fool proof measures was proposed. Third, alternative revision as cognitive accident prevention for the fail safe measures was proposed.