• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.301-308
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• 2020

Based on the analysis of fire escape situations in public facility, this study was intended to propose a design of emergency light suitable for fire in public facility. A video analysis was conducted to understand the evacuation situation of public facility because the fire could not be randomized due to the disaster. Through video analysis, we were able to identify inconvenience and necessary needs in avoiding fire in public facility and reflected them in the design of emergency light, etc. As a result of the design of emergency light, the wall type induction lamp had different LED layout structures to minimize the thickness of the product. Ceiling induction lamps have been supplemented for additional installation in corridors of complex structures. The results of this study are designed based on the criteria used in the manufacture of actual emergency light and we intend to explore ways to be practical through further experiment measurements and complementary steps through expert advice.

• Fire Science and Engineering
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• v.33 no.3
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• pp.91-97
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• 2019

In Korea, the Ministry of Environment's Chemical Control Act is the basis for hazardous chemical substances and safety management is being carried out. In particular, the standards for the installation and management of facilities are strongly managed. There were problems in the early stages of implementation, conflict with other laws, size of facilities and non-reflection of material properties. In this study, more realistic and reasonable improvement was planned for the fire-resistance standard of buildings among these facilities. We compared the fire resistance standards of buildings in the Korean similar chemical facility safety management ordinance. Key problems were identified through examples of representative complaints concerning the criteria for facilities. Finally, the Chemical Control Act provided an improvement measure to apply the building fire-resistance standard by clarifying the size and chemical of facilities. In the future, the results of this study are expected to be consistent with the basic purpose of the Chemicals Contral Act considering environmental hazards and contribute to the standard of handling facilities of reasonable chemical management laws that can be applied to the industry in reality.

• Journal of Radiation Protection and Research
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• v.36 no.1
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• pp.35-43
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• 2011

The PHENIX Experiment is the largest of the four experiments that have taken data at the Relativistic Heavy Ion Collider. PHENIX, the Pioneering High Energy Nuclear Interaction eXperiment, is designed specifically to measure direct probes of the collisions such as electrons, muons, and photons. The primary goal of PHENIX is to discover and study a new state of matter called the Quark-Gluon Plasma. Among many particles, muons coming from W-boson decay gives us key information to analyze the spin of proton. Resistive plate chambers are proposed as a suitable solution as a muon trigger because of their fast response and good time resolution, flexibility in signal readout, robustness and the relatively low cost of production. The RPC detectors for upgrade were assembled and their performances were evaluated. The procedure to make the detectors better was optimized and described in detail in this thesis. The code based on ROOT was written and by using this the performance of the detectors made was evaluated, and all of the modules for north muon arm met the criteria and installation at PHENIX completed in November 2009. As RPC detectors that we made showed fast response, capacity of covering wide area with a resonable price and good spatial resolution, this will give the opportunity for applications, such as diagnosis and customs inspection system.

• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.74-81
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• 2004

The KSNP Steam Generators (Youngkwang Unit 3 and 4, Ulchin Unit 3 and 4) have a problem of U-tube fretting wear due to Flow Induced Vibration (FIV). In particular, the wear is localized and concentrated in a small area of upper part of U-bend in the Central Cavity region. The region has some conditions susceptible to the FIV, which are high flow velocity, high void fraction, and long unsupported span. Even though the FIV could be occurred by many mechanisms, the main mechanism would be fluid-elastic instability, or turbulent excitation. To remedy the problem, Eggcrate Flow Distribution Plate (EFDP) was installed in the Central Cavity region or Ulchin Unit 5 and 6 steam generators, so that it reduces the flow velocity in the region to a certain level. However, the cause of the FIV and the effectiveness of the EFDP was not thoroughly studied and checked. In this study, therefore the Stability Ratio (SR), which is the ratio of the actual velocity to the critical velocity, was compared between the value before the installation of EFDP and that after. Also the possibility of fluid-elastic instability of KSNP steam generator and the effectiveness of EFDP were checked based on the ATHOS3 code calculation and the Pettigrew's experimental results. The calculated results were plotted in a fluid-elastic instability criteria-diagram (Pettigrew, 1998, Fig. 9). The plotted result showed that KSNP steam generator with EFDP had the margin of Fluid-Elastic Instability by almost 25％.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.10-20
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• 2020

Purpose: Analyze the results of on-site inspection of the tunnel structure maintenance management monitoring and suggest improvement plans. Method: We investigate and analyze the problems of various items on maintenance monitoring of tunnel structure of 14 subway lines of Seoul subway in downtown area. Result: The maintenance monitoring items, measurement quantity and installation location are classified into open tunnel and excavation tunnel and improvement plans are suggested respectively. Various durability criteria of the measuring instruments were examined, and durability confirmation method suggested improvement measures such as approval, inspection, inspection and testing, calibration of monitoring sensors. Conclusion: Applying the improvement measures of the tunnel structure maintenance monitoring to the construction site will increase the efficiency of the maintenance monitoring and contribute to the development of construction monitoring technology.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.13-21
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• 2017

PURPOSES : In this research, an SB3-level roadside barrier for a highway transition zone that meets the newly established guide Installation and Management Guide for Roadside Safety Appurtenance is developed. Its performance is evaluated by a numerical simulation and real-scale vehicle impact test. METHODS : The commercial explicit dynamic software LS-DYNA is utilized for impact simulation. An FE model of a passenger vehicle developed and released by the National Crash Analysis Center (NCAC) at George Washington University and a heavy goods vehicle (HGV) model developed by the TC226/CM-E Work Group are utilized for impact simulation. The original vehicle models were modified to reflect the conditions of test vehicles. The impact positions of the passenger vehicle and truck to the transition guardrail were set as 1/2 and 3/4 of the transition region, respectively, according to the guide. RESULTS : Based on the numerical simulation results of the existing transition barrier, a new structural system with improved performance was suggested. According to the result of a numerical simulation of the suggested structural system, two sets of transition barriers were manufactured and installed for real-scale vehicle impact tests. The tests were performed at a test field for roadside safety hardware of the Korea Highway Corporation Research Institute. CONCLUSIONS : The results of both the real-vehicle impact tests and numerical simulations of the developed transition barrier satisfied the performance criteria, and the results of numerical simulation showed good correlation with the test results.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.4
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• pp.427-440
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• 2016

Various kinds of processes are used in the Public Sewage Treatment Works(PSTWs) in order to achieve water quality criteria and TMDL in the watershed. The performance of the existing processes at PSTWs depends on influent characteristics, effluent quality target, amount of sludge production, power cost and other factors. In present, the Selection Guideline for the Available Treatment Process of PSTWs is used for a process decision in the country. But there are some problems regarding redundancy of assessment factors and complexity of assessment procedure in the guideline. In this study, we did a test application of AHP for process selection of PSTWs, which propose is to simplify assessment factors such as pollutant removal amount, sludge generation, electricity consumption, stability of operation, convenience of maintenance, easiness of existing process application, installation cost, and operating cost concerning of environmental factors, technical factors and economical factors. According to the study, the PSTWs selection procedure guideline can be improved using application of AHP method.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.289-294
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• 2011

The installation of joint is to prevent random cracking due to drying shrinkage stress of concrete slab. However contraction joint spacing is empirically implemented into slab constructions without detail calculation based on quantitative criteria. In this study, shrinkage strain of concrete due to concrete shrinkage stress was measured to suggest joint spacing based on the study results. The test environmental conditions were applied temperature of $15^{\circ}C$ and relative humidity of 60%. The design compressive strength used was 30 MPa and 40 MPa, which are currently used in concrete slab designs. The drying shrinkage test result was applied to drying shrinkage models (ACI 209R, CEB MC 90, B3, GL 2000 and Sakata). The results showed that the most appropriate model was ACI 209R model. Based on the research findings, quantitative contraction joint spacing locations were calculated.

• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.423-432
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• 2014

The aim of this study to propose an efficient method in selecting the type of new and renewable energy applied in at the planning phase of buildings. This study applied geothermal energy facilities with high adaptability to buildings. This study considered the energy reduction and reduced cost by comparing the values with the energy consumption before applying of geothermal energy facilities. In order to propose more reliable criteria of economic evaluation, maintenance costs reflecting the replacement cycles and initial construction costs by drawings and specifications for installation facilities for practical geothermal energy based on construction statement for life-cycle cost analysis. The results will help to effectively select economic types of facilities for new and renewable energy of the planning phase of buildings.

• Journal of the Korean Institute of Gas
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• v.22 no.1
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• pp.45-52
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• 2018

In this study, 398 city gas pipe systems installed on the bridges were surveyed and analyzed classified characteristics about the ages, length, and remote isolation devices installed or not. As a result of analysis, 43.0% pipes have been used more than 20 years and 89.4% do not have remote cut-off devices, so this study suggest safety management ways for the issues. Chosen 76 pipes were researched stress strain characteristics by CAESAR-II which is a specialized program for stress analysis. And, when a loop is installed on the bridge pipe, effect on code stress by the location and size of the loop was performed. This study can help to improve safety level by revising criteria of new installation, inspection and diagnostic.