• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.116-122
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• 2014

This study proposes a system reliability analysis of rack storage facilities subjected to forklift colliding events. The proposed system reliability analysis consists of two steps: the first step is to identify dominant failure modes that most contribute to the failure of the whole rack facilities, and the second step is to evaluate the system failure probability. In the first step, dominant failure modes are identified by using a simulation-based selective searching technique where the contribution of a failure mode to the system failure is roughly estimated based on the distance from the origin in the space of the random variables. In the second step, the multi-scale system reliability method is used to compute the system reliability where the first-order reliability method (FORM) is initially used to evaluate the component failure probability (failure probability of one member), and then the probabilities of the identified failure modes and their statistical dependence are evaluated, which is called as the lower-scale reliability analysis. Since the system failure probability is comprised of the probabilities of the failure modes, a higher-scale reliability analysis is performed again based on the results of the lower-scale analyses, and the system failure probability is finally evaluated. The illustrative example demonstrates the results of the system reliability analysis of the rack storage facilities subjected to forklift impact loadings. The numerical efficiency and accuracy of the approach are compared with the Monte Carlo simulations. The results show that the proposed two-step approach is able to provide accurate reliability assessment as well as significant saving of computational time. The results of the identified failure modes additionally let us know the most-critical members and their failure sequence under the complicated configuration of the member connections.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.109-118
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• 2010

This study quantified the flood reduction effect of small stormwater detention facilities by the NRCS curve number. The modified rational equation was used to calculate the inflow volume into the detention facilities. The NRCS curve number in the cases w/ and w/o storage facility was calculated with respect to the rainfall characteristics(rainfall frequency, duration) and the size of storage facilities. Finally, diagrams showing the curve number reduction rate versus the size of storage facility were developed. The diagrams can be used to evaluate the flood reduction effect of storage facility reasonably and efficiently when estimating the optimal location and size of storage facility. The results based on the methodology propsed in this study were also compared with those of previous study for their validation.

• Journal of the Korea Safety Management & Science
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• v.20 no.3
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• pp.27-36
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• 2018

The steel pipe manufacturing industry deals with facilities and materials. Especially thermal facilities are close to vapor cloud explosion (VCE) and may cause secondary damage to facilities because they deal with corrosive substances such as hydrofluoric acid, sulfuric acid and acid, fire, explosion, leakage etc. It is in danger. In this study, hazard identification method was conducted using HAZOP techniques and quantitative risk analysis was conducted using e-CA, a program that supports accident impact analysis. Equipment in the influence range of ERPG - 3 was determined to be a facility requiring replacement. It was decided that neutralization is necessary using slaked lime. Based on the cost of loss, We presented the proper replacement which is the timing of the dangerous facility. As a result, It was ideal to replace the facilities with 20 years of heat treatment facilities, one year of hydrofluoric acid storage tank, 20 years of sulfuric acid storage tank, and 5 years of hydrochloric acid storage tank.

• Journal of the Korean Wood Science and Technology
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• v.52 no.3
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• pp.276-288
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• 2024

This study was conducted to reproduce the woodworking process of Baekje wooden storage facilities. Green timber of Quercus spp. was processed using ancient woodworking tools, and the tool-trace formed in this process were compared with the tool-trace of actual excavated artifacts. In the tool-trace analysis, the length and shape of the tool-trace were objectively recorded using a 3D Scan, and that were difficult to confirm with photograph were confirmed through stereoscopic microscope. As a result, there were two types of adze's tool-trace. One of them is minute straight Blade-top trace line when trimming the wood surface and the other is Plucked trace that appear when strongly chop at the wood. When a chisel bat was not used, a long and wide continuous shape blade trace was produced. And when the chisel head was struck with the chisel bat, a straight blade-top trace was regularly observed. Saw-trace was identified in several layers with fine straight stripes. Through this, it was found that the tool-trace of the woodworking tools, which is estimated to have been used in each process, and the tool-trace remaining in the Baekje wooden storage facility coincide.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.490-497
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• 2007

A Combined sewer overflows (CSOs) are themselves a significant source of water pollution. Therefore, the control of urban drainage for CSOs reduction and receiving water quality protection is needed. Examples in combined sewer systems include downstream storage facilities that detain runoff during periods of high flow and allow the detained water to be conveyed by an interceptor sewer to a centralized treatment plant during periods of low flow. The design of such facilities as stormwater detention storage is highly dependant on the temporal variability of storage capacity available (which is influenced by the duration of interevent dry periods) as well as the infiltration capacity of soil and recovery of depression storage. As a result, a continuous approach is required to adequately size such facilities. This study for the continuous long-term analysis of urban drainage system used analytical probabilistic model based on derived probability distribution theory. As an alternative to the modeling of urban drainage system for planning or screening level analysis of runoff control alternatives, this model have evolved that offer much ease and flexibility in terms of computation while considering long-term meteorology. This study presented rainfall and runoff characteristics of the subject area using analytical probabilistic model. This study presented the average annual COSs and number of COSs when the interceptor capacity is in the range $3{\times}DWF$ (dry weather flow). Also, calculated the average annual mass of pollutant lost in CSOs using Event Mean Concentration. Finally, this study presented a decision of storage volume for CSOs reduction and water quality protection.

• Journal of the Korean Institute of Gas
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• v.13 no.1
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• pp.14-20
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• 2009

As the consumption of LNG has increased, the capacity and number of LNG facilities are getting bigger and bigger. Such circumstances supports the need for a dedicated risk analysis model to help review and check major issues of the safer construction and operation of LNG storage facilities systematically. Therefore this study suggests an appropriate risk analysis model that enables us to evaluate hazards of LNG storage facilities more easily and systematically, and then to use its result in siting, design and construction stages of the facilities. ill order to develop the model, lots of existing studies and domestic and foreign codes and standards were fully reviewed and a series of case studies also were carried out. The suggested model consists of 4-stage evaluations: in selecting a site, in determining a layout, in designing and constructing the facilities, and in operating them. This model also suggests the weather condition necessary for estimating the consequence of accident-scenarios, and the easy, systematic approach to the analysis of their probability. We expect that the model may help secure LNG storage facilities' inherent safety in determining their site and layout.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.4
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• pp.402-411
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• 2013

Objectives: This study aims to assess the concentrations of ammonia and hydrogen sulfide according to task unit area at swine farms. Methods: A total of six swine farms were selected for this study. Ammonia and hydrogen sulfide were monitored using a real-time multi-gas monitor which could sample the gases simultaneously. The sampling was done in the pig building, manure storage facility and composting facility of each farm. Results: The concentration of ammonia in the pig buildings(GM 22.6 ppm, GSD 2.3) was significantly higher(p<0.0001) than in the manure storage facilities(GM 10.4 ppm, GSD 2.7) and composting facilities(GM 8.6 ppm, GSD 2.8). The concentration of hydrogen sulfide in the manure storage facilities(GM 9.8 ppm, GSD 3.2) was higher(p<0.0001) than in the pig buildings(GM 2.3 ppm, GSD 2.3) and composting facilities(GM 1.9 ppm, GSD 2.5). In particular, the levels of hydrogen sulfide in the confined manure storage facilities were higher than those in open-type facilities and the peak concentration(98 ppm) in the confined facilities was approximate to 100 ppm, at the value of Immediately Dangerous to Life or Health(IDLH). Conclusions: Suffocation accidents caused by hazardous gases at a swine farm have occurred annually. Real-time monitoring of the hazards should be done in order to protect farm workers and livestock from the sudden accidents.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.722-728
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• 2012

Urban sewer systems has a limitation of capacity of rainwater storage and problem of occurrence of untreated sewage, so adopting a storage facility for sewer flooding prevention and urban non-point pollution reduction has a big attention. The Korea Ministry of Environment has recently introduced a new concept of "multi-functional storage facility", which is crucial not only in preventive stormwater management but also in dealing with combined sewer overflow and sanitary sewer discharge, and also has been promoting its adoption. However, reserving a space for a single large-scale storage facility might be difficult especially in urban areas. Thus, decentralized construction of small- and midium-sized storage facilities and its operation have been introduced as an alternative way. In this paper, we propose a model predictive control scheme for an optimized operation of distributed storage facilities and sewer networks. To this aim, we first describe the mathematical model of each component of networks system which enables us to analyze its detailed dynamic behavior. Second, overflow locations and volumes will be predicted based on the developed network model with data on the external inflow occurred at specific locations of the network. MPC scheme based on the introduced particle swarm optimization technique then produces the optimized the gate setting for sewer network flow control, which minimizes sewer flooding and maximizes the potential storage capacity. Finally, the operational efficacy of the proposed control scheme is demonstrated by simulation study with virtual rainstorm event.

• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.218-225
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• 2007

This study was conducted to investigate the satisfaction of school dietitians with foodservice facilities and utilities in the Chonbuk area of Korea. Self-administered questionnaires were collected from a total of 22 dietitians. Statistical data analysis was completed using the SPSS v. 10.0 program. The results are summarized as follows. Among the 222 school foodservice systems, 68.5% of the schools prepared meals the conventional way and 31.5% prepared them the commissary way. Most of the school foodservice facilities were located on the first floor. Satisfaction with the location of the foodservice facility was not significantly different between the conventional and commissary systems. However, overall dietitian satisfaction with the foodservice facility locations was poor. Approximately 30% of the dietitians responded that one of the most important problems for foodservice management was the limited space and worn-out equipments in the kitchens. For dietitians' satisfaction on the types of facilities present, most schools had constructed dietitian offices, food storage facilities, cafeterias, rest rooms, dressing rooms, and preparation facilities. Yet, the amenities most often missing were storage facilities, preparation facilities, dressing rooms, rest rooms, etc. For overall satisfaction with the status of facilities and utilities, we found no significant differences between dietitians in the conventional(2.89) and commissary foodservice systems(2.86); however, the satisfaction level among the dietitians was poor. Therefore, governmental regulation agencies need to review and approve plans prior to the new construction or extensive remodeling of school foodservice facilities. Finally, content analysis was also conducted regarding the dietitians' opinions on foodservice facilities and utilities.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.219-225
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• 2000

Agricultural irrigation facilities are designed to storage, carriage, distribution and drainage water. Although those facilities may have different primary purposes, their technical functions are interrelated systematically. This Study aimed at developing the optimized object for integrated design for irrigation facilities. of reservoir and channel facilities, which are related by irrigation system design. So, total 17 elementary facility object was developed.