• Title/Summary/Keyword: Standard facility

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A Study of Statistic Behavior of Segmental U-shaped Prestressed Concrete Girder Applied with Integrated Tensioning Systems (복합긴장방식이 적용된 세그멘탈 U형 거더 정적 거동 연구)

  • Hyunock Jang;Ilyoung Jang
    • Journal of the Society of Disaster Information
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    • v.20 no.2
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    • pp.329-338
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    • 2024
  • Purpose: This study verified the safety of the improved box-type girder behavior by comparing and evaluating the bending behavior results of a full-scale specimen based on the analytical behavior of the splice element PSC U-shaped girder with integrated tensioning systems. Method: Based on the results of the service and strength limit state design using the bridge design standard(limit state design method), the applied load of a 40m full-scale specimen was calculated and a static loading experiment using the four-point loading method was performed. Result: When the design load, crack load, and ultimate load were applied, the specimen deflection occurred at 97.1%, 98.5%, and 79.0% of the analytical deflection value. When the design load, crack load, and ultimate load were applied, the crack gauge was measured at 0.009~0.035mm, 0.014~0.050mm, and 6.383~5.522mm at each connection. Conclusion: The specimen behaved linear-elastically until the crack load was applied, and after cracks occurred, it showed strainhardening up to the ultimate load, and it was confirmed that the resistance of bending behavior was clearly displayed against the applied load. The cracks in the dry joints were less than 25% of grade B based on the evaluation of facility condition standard. The final residual deformation after removing the ultimate load was 0.114mm, confirming the stable behavior of the segment connection.

A Study on the Establishment and Application of Evaluation Criteria for Old Railway Station Considering the Level of Railway Service (철도 서비스수준을 고려한 노후철도역사 평가기준 마련 및 적용방안)

  • Kim, Kyung Ho;Kim, Si Gon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.1
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    • pp.101-108
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    • 2024
  • The total number of railroad stations managed in Korea is 322 (including general and wide-area railways), and a considerable number of stations are aging. In terms of the size of the existing railway station and the number of entrances, it has not been possible to secure adequate service capacity, and the demand for station improvement is increasing due to changes in surrounding conditions such as urban development. In the past, railroad stations were focused on the simple function of a connection passage in terms of maintenance or management, but in recent years, railroad stations are also changing to an atmosphere that they should be reborn as a user-centered comfortable, convenient, and safe service provision space. In this study, a case study related to the improvement of the old railway station was conducted to derive an improvement plan that meets the improvement standard of the old station, and the service level evaluation standard was developed. By introducing the concept of service level (LOS) in the development model, station congestion, station movement convenience, and station safety were selected as evaluation indicators. In addition, this development model applied an analytical stratification technique to divide various evaluation elements of each indicator into major and detailed elements and derive the relative importance of the elements by class. Priority for improvement was derived using the ratio of the number of E and F on the LOS for each facility. Based on this study, it is expected to be helpful in using it as an evaluation criterion for improving objective and equitable railway station.

Development of an Efficiency Calibration Model Optimization Method for Improving In-Situ Gamma-Ray Measurement for Non-Standard NORM Residues (비정형 공정부산물 In-Situ 감마선 측정 정확도 향상을 위한 효율교정 모델 최적화 방법 개발)

  • WooCheol Choi;Tae-Hoon Jeon;Jung-Ho Song;KwangPyo Kim
    • Journal of Radiation Industry
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    • v.17 no.4
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    • pp.471-479
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    • 2023
  • In In-situ radioactivity measurement techniques, efficiency calibration models use predefined models to simulate a sample's geometry and radioactivity distribution. However, simplified efficiency calibration models lead to uncertainties in the efficiency curves, which in turn affect the radioactivity concentration results. This study aims to develop an efficiency calibration optimization methodology to improve the accuracy of in-situ gamma radiation measurements for byproducts from industrial facilities. To accomplish the objective, a drive mechanism for rotational measurement of an byproduct simulator and a sample was constructed. Using ISOCS, an efficiency calibration model of the designed object was generated. Then, the sensitivity analysis of the efficiency calibration model was performed, and the efficiency curve of the efficiency calibration model was optimized using the sensitivity analysis results. Finally, the radiation concentration of the simulated subject was estimated, compared, and evaluated with the designed certification value. For the sensitivity assessment of the influencing factors of the efficiency calibration model, the ISOCS Uncertainty Estimator was used for the horizontal and vertical size and density of the measured object. The standard deviation of the measurement efficiency as a function of the longitudinal size and density of the efficiency calibration model decreased with increasing energy region. When using the optimized efficiency calibration model, the measurement efficiency using IUE was improved compared to the measurement efficiency using ISOCS at the energy of 228Ac (911 keV) for the nuclide under analysis. Using the ISOCS efficiency calibration method, the difference between the measured radiation concentration and the design value for each simulated subject measurement direction was 4.1% (1% to 10%) on average. The difference between the estimated radioactivity concentration and the design value was 3.6% (1~8%) on average when using the ISOCS IUE efficiency calibration method, which was closer to the design value than the efficiency calibration method using ISOCS. In other words, the estimated radioactivity concentration using the optimized efficiency curve was similar to the designed radioactivity concentration. The results of this study can be utilized as the main basis for the development of regulatory technologies for the treatment and disposal of waste generated during the operation, maintenance, and facility replacement of domestic byproduct generation facilities.

Landscape Object Classification and Attribute Information System for Standardizing Landscape BIM Library (조경 BIM 라이브러리 표준화를 위한 조경객체 및 속성정보 분류체계)

  • Kim, Bok-Young
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.2
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    • pp.103-119
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    • 2023
  • Since the Korean government has decided to apply the policy of BIM (Building Information Modeling) to the entire construction industry, it has experienced a positive trend in adoption and utilization. BIM can reduce workloads by building model objects into libraries that conform to standards and enable consistent quality, data integrity, and compatibility. In the domestic architecture, civil engineering, and the overseas landscape architecture sectors, many BIM library standardization studies have been conducted, and guidelines have been established based on them. Currently, basic research and attempts to introduce BIM are being made in Korean landscape architecture field, but the diffusion has been delayed due to difficulties in application. This can be addressed by enhancing the efficiency of BIM work using standardized libraries. Therefore, this study aims to provide a starting point for discussions and present a classification system for objects and attribute information that can be referred to when creating landscape libraries in practice. The standardization of landscape BIM library was explored from two directions: object classification and attribute information items. First, the Korean construction information classification system, product inventory classification system, landscape design and construction standards, and BIM object classification of the NLA (Norwegian Association of Landscape Architects) were referred to classify landscape objects. As a result, the objects were divided into 12 subcategories, including 'trees', 'shrubs', 'ground cover and others', 'outdoor installation', 'outdoor lighting facility', 'stairs and ramp', 'outdoor wall', 'outdoor structure', 'pavement', 'curb', 'irrigation', and 'drainage' under five major categories: 'landscape plant', 'landscape facility', 'landscape structure', 'landscape pavement', and 'irrigation and drainage'. Next, the attribute information for the objects was extracted and structured. To do this, the common attribute information items of the KBIMS (Korean BIM Standard) were included, and the object attribute information items that vary according to the type of objects were included by referring to the PDT (Product Data Template) of the LI (UK Landscape Institute). As a result, the common attributes included information on 'identification', 'distribution', 'classification', and 'manufacture and supply' information, while the object attributes included information on 'naming', 'specifications', 'installation or construction', 'performance', 'sustainability', and 'operations and maintenance'. The significance of this study lies in establishing the foundation for the introduction of landscape BIM through the standardization of library objects, which will enhance the efficiency of modeling tasks and improve the data consistency of BIM models across various disciplines in the construction industry.

Estimation of Optimal Size of the Treatment Facility for Nonpoint Source Pollution due to Watershed Development (비점오염원의 정량화방안에 따른 적정 설계용량결정)

  • Kim, Jin-Kwan
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.6
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    • pp.149-153
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    • 2008
  • The pollutant capacity occurred before and after the development of a watershed should be quantitatively estimated and controlled for the minimization of water contamination. The Ministry of Environment suggested a guideline for the legal management of nonpoint source from 2006. However, the rational method for the determination of treatment capacity from nonpoint source proposed in the guideline has the problem in the field application because it does not reflect the project based cases and overestimates the pollutant load to be reduced. So, we perform the standard rainfall analysis by analytical probabilistic method for the estimation of an additional pollutant load occurred by a project and suggest a methodology for the estimation of contaminant capacity instead of a simple rational method. The suggested methodology in this study could determine the reasonable capacity and efficiency of a treatment facility through the estimation of pollutant load from nonpoint source and from this we can manage the watershed appropriately. We applied a suggested methodology to the projects of housing land development and a dam construction in the watersheds. When we determine the treatment capacity by a rational method without consideration of the types of projects we should treat the 90% of pollutant capacity occurred by the development and to do so, about 30% of the total cost for the development should be invested for the treatment facility. This requires too big cost and is not realistic. If we use the suggested method the target pollutant capacity to be reduced will be 10 to 30% of the capacity occurred by the development and about 5 to 10% of the total cost can be used. The control of nonpoint source must be performed for the water resources management. However it is not possible to treat the 90% of pollutant load occurred by the development. The proper pollutant capacity from nonpoint source should be estimated and controlled based on various project types and in reality, this is very important for the watershed management. Therefore the results of this study might be more reasonable than the rational method proposed in the Ministry of Environment.

A Study on the Characteristics of Condensable Fine Particles in Flue Gas (배출가스 중 응축성미세먼지 특성 연구)

  • Gong, Buju;Kim, Jonghyeon;Kim, Hyeri;Lee, Sangbo;Kim, Hyungchun;Jo, Jeonghwa;Kim, Jeonghun;Gang, Daeil;Park, Jeong Min;Hong, Jihyung
    • Journal of Korean Society for Atmospheric Environment
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    • v.32 no.5
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    • pp.501-512
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    • 2016
  • The study evaluated methods to measure condensable fine particles in flue gases and measured particulate matter by fuel and material to get precise concentrations and quantities. As a result of the method evaluation, it is required to improve test methods for measuring Condensable Particulate Matter (CPM) emitted after the conventional Filterable Particulate Matter (FPM) measurement process. Relative Standard Deviation (RSD) based on the evaluated analysis process showed that RSD percentages of FPM and CPM were around 27.0~139.5%. As errors in the process of CPM measurement and analysis can be caused while separating and dehydrating organic and inorganic materials from condensed liquid samples, transporting samples, and titrating ammonium hydroxide in the sample, it is required to comply with the exact test procedures. As for characteristics of FPM and CPM concentrations, CPM had about 1.6~63 times higher concentrations than FPM, and CPM caused huge increase in PM mass concentrations. Also, emission concentrations and quantities varied according to the characteristics of each fuel, the size of emitting facilities, operational conditions of emitters, etc. PM in the flue gases mostly consisted of CPM (61~99%), and the result of organic/inorganic component analysis revealed that organic dusts accounted for 30~88%. High-efficiency prevention facilities also had high concentrations of CPM due to large amounts of $NO_x$, and the more fuels, the more inorganic dusts. As a result of comparison between emission coefficients by fuel and the EPA AP-42, FPM had lower result values compared to that in the US materials, and CPM had higher values than FPM. For the emission coefficients of the total PM (FPM+CPM) by industry, that of thermal power stations (bituminous coal) was 71.64 g/ton, and cement manufacturing facility (blended fuels) 18.90 g/ton. In order to estimate emission quantities and coefficients proper to the circumstances of air pollutant-emitting facilities in Korea, measurement data need to be calculated in stages by facility condition according to the CPM measurement method in the study. About 80% of PM in flue gases are CPM, and a half of which are organic dusts that are mostly unknown yet. For effective management and control of PM in flue gases, it is necessary to identify the current conditions through quantitative and qualitative analysis of harmful organic substances, and have more interest in and conduct studies on unknown materials' measurements and behaviors.

Indoor Exposure and Health Risk of Polycyclic Aromatic Hydrocarbons (PAHs) via Public Facilities PM2.5, Korea (II)

  • Kim, Ho-Hyun;Lee, Geon-Woo;Yang, Ji-Yeon;Jeon, Jun-Min;Lee, Woo-Seok;Lim, Jung-Yun;Lee, Han-Seul;Gwak, Yoon-Kyung;Shin, Dong-Chun;Lim, Young-Wook
    • Asian Journal of Atmospheric Environment
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    • v.8 no.1
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    • pp.35-47
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    • 2014
  • The purpose of the study is to evaluate the pollution level (gaseous and particle phase) in the public facilities for the PAHs, non-regulated materials, forecast the risk level by the health risk assessment (HRA) and propose the guideline level. PAH assessments through sampling of particulate matter of diameter < 2.5 ${\mu}m$ ($PM_{2.5}$). The user and worker exposure scenario for the PAHs consists of 24-hour exposure scenario (WIES) assuming the worst case and the normal exposure scenario (MIES) based on the survey. This study investigated 20 PAH substances selected out of 32 substances known to be carcinogenic or potentially carcinogenic. The risk assessment applies major toxic equivalency factor (TEF) proposed from existing studies and estaimates individual Excess Cancer Risk (ECR). The study assesses the fine dusts ($PM_{2.5}$) and the exposure levels of the gaseous and particle PAH materials for 6 spots in each 8 facility, e.g. underground subway stations, child-care facilities, elderly care facilities, super market, indoor parking lot, terminal waiting room, internet caf$\acute{e}$ (PC-rooms), movie theater. For internet caf$\acute{e}$ (PC-rooms) in particular, that marks the highest $PM_{2.5}$ concentration and the average concentration of 10 spots (2 spots for each cafe) is 73.3 ${\mu}g/m^3$ (range: 6.8-185.2 ${\mu}g/m^3$). The high level of $PM_{2.5}$ seen in internet cafes was likely due to indoor smoking in most cases. For the gaseous PAHs, the detection frequency for 4-5 rings shows high and the elements with 6 rings shows low frequency. For the particle PAHs, the detection frequency for 2-3 rings shows low and the elements with 6 rings show high frequency. As a result, it is investigated that the most important PAHs are the naphthalene, acenaphthene and phenanthrene from the study of Kim et al. (2013) and this annual study. The health risk assessment demonstrates that each facility shows the level of $10^{-6}-10^{-4}$. Considering standards and local source of pollution levels, it is judged that the management standard of the benzo (a)pyrene, one of the PAHs, shall be managed with the range of 0.5-1.2 $ng/m^3$. Smoking and ventilation were considered as the most important PAHs exposure associated with public facility $PM_{2.5}$. This study only estimated for inhalation health risk of PAHs and focused on the associated cancer risk, while multiple measurements would be necessary for public health and policy.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Effects of Forest Road Construction on Stream Water Qualities(I) - The Variation of Suspended Sediment by Forest Road Construction - (임도개설(林道開設)이 계류수질(溪流水質)에 미치는 영향(影響)(I) - 임도개설(林道開設)에 따른 부유토사량(浮遊土砂量)의 변화(變化) -)

  • Chun, Kun-Woo;Kim, Min-Sik;Ezaki, Tsugio
    • Journal of Korean Society of Forest Science
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    • v.85 no.2
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    • pp.280-287
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    • 1996
  • This study was carried out to investigate the export rate of suspended sediment by different precipitation intensity after forest road construction for torrential streams on three different watersheds with various forest road density(Watershed A : 6.67m/ha, Watershed B : 5.52m/ha, and Watershed C : control) in the Experimental Forest of Kangwon National University. The results were as follows. 1. Closely related to the the amount of rainfall in both 1994 and 1995, the average streanfkiw rate was less than $0.25{\times}10^4m^3/day$ during May and June and $5.0{\times}10^4m^3/day$ during July and August. More than $25{\times}10^4m^3/day$ of streanflow rate was occurred twice in 1994 and seven times in 1995. 2. The amount of suspended sediment in three watersheds was less than standard of drinking water(25mg/l) before road construction with daily rainfall of 74mm, 92mm, and 120mm in 1994, also after road construction with daily rainfall of 21mm and 47mm in 1995. But, under the 192mm of daily rainfall, Watershed C did not show the difference in the amount of suspended sediment, however, Watershed A and B produced 1,525mg/l and 775mg/l, respectively, which is 61 and 31 fold of stabdard of drinking water, and construction to export for 35 hours after rainfall. 3. The maximum amount of suspended sediment was less than the standard of drinking water with light rainfall before and after road construction. Under the 192mm of daily rainfall, the maximum amounts of suspended sediment in Watershed A and B were 13,150mg/l and 2,690mg/l, of 526 and 108 fold of standard of drinking water, respectively, showing obvious water pollution by sedimentation. Results of the study indicated that the forest road construction had great influence on the sedimentation, and getting increased by higher road density and heavier rainfall. Therefore such practices as vegetation covering and soil erosion control facility should be established accompanying with forest road construction to prevent from sedimentation.

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Microbiological Hazard Analysis for HACCP System Application to Non Heat-Frozen Carrot Juice (비가열냉동 당근주스의 HACCP 시스템 적용을 위한 미생물학적 위해 분석)

  • Lee, Ung-Soo;Kwon, Sang-Chul
    • Journal of Food Hygiene and Safety
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    • v.29 no.2
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    • pp.79-84
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    • 2014
  • This study has been performed for about 270 days at analyzing biologically hazardous factors in order to develop HACCP system for the non heat-frozen carrot juice. A process chart was prepared by manufacturing process of raw agricultural products of non heat-frozen carrot juice, which was contained water and packing material, storage, washing, cutting, extraction of the juice, internal packing, metal detection, external packing, storage and consignment (delivery). As a result of measuring Coliform group, Staphylococcus aureus, Salmonella spp., Bacillus cereus, Listeria Monocytogenes, Enterohemorrhagic E. coli before and after washing raw carrot, Standard plate count was $4.7{\times}10^4CFU/g$ before washing but it was $1.2{\times}10^2CFU/g$ detected after washing. As a result of testing airborne bacteria (Standard plate count, Coliform group, Yeast and Fungal) depending on each workplace, number of microorganism of in packaging room, shower room and juice extraction room was detected to be 10 CFU/Plate, 60 CFU/Plate, 20 CFU/Plate, respectively. As a result of testing palm condition of workers, as number of Standard plate count, Coliform group and Staphylococcus aureus was represented to be high as $6{\times}10^4CFU/cm^2$, $0CFU/cm^2$ and $0CFU/cm^2$, respectively, an education and training for individual sanitation control was considered to be required. As a result of inspecting surface pollution level of manufacturing facility and devices, Coliform group was not detected in all the specimen but Standard plate count was most dominantly detected in scouring kier, scouring kier tray, cooling tank, grinding extractor, storage tank and packaging machine-nozzle as $8.00{\times}10CFU/cm^2$, $3.0{\times}10CFU/cm^2$, $4.3{\times}10^2CFU/cm^2$, $7.5{\times}10^2CFU/cm^2$, $6.0{\times}10CFU/cm^2$, $8.5{\times}10^2CFU/cm^2$ respectively. As a result of analyzing above hazardous factors, processing process of ultraviolet ray sterilizing where pathogenic bacteria may be prevented, reduced or removed is required to be controlled by CCP-B (Biological) and critical level (critical control point) was set at flow speed is 4L/min. Therefore, it is considered that thorough HACCP control plan including control criteria (point) of seasoning fluid processing process, countermeasures in case of its deviation, its verification method, education/training and record control would be required.