• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.715-724
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• 2022

With the enforcement of the infrastructure management act, the importance of utility tunnels that jointly accommodate life-lines such as electricity, communication, water supply, and heating facilities has increased. The currently applied utility tunnel maintenance system is managed in an accident-preventive safety-based evaluation method. However, this evaluation method has limitations in effective maintenance. In this study, performance evaluation items were derived through the Delphi method to suggest a criterion for quantitatively evaluating the performance of utility tunnels, and the weights for each item were calculated through the Analytic Hierarchy Process (AHP) method. In the future, it is judged that a more reasonable performance evaluation standard of utility tunnel can be prepared if modifications and supplements are made through field application.

• Journal of the Korea Safety Management & Science
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• v.22 no.4
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• pp.9-15
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• 2020

As of 2018, total yield of lettuce and strawberry amounted to 93,543 tons (representing 1.0 percent) and 183,639 tons (2.0 percent), respectively, among total yields worth 9,185,889 tons in South Korea. Lettuce is affected by a combination of numerous elements such as varieties, cultivation methods and pests during each growth phase (Lee et al., 1999). It is mainly cultivated in spring and fall. Especially due to respiration rate after harvest leading to reduced quality and poor storage, maintaining annual supply is unavailable (Jang et al., 2018). With the distribution of new varieties, forcing culture and indoor insulated facilities for plant cultivation during winter, strawberries are produced every year except for late summer and early fall. Due to active respiration, transpiration, soft flesh and high water content, the fruit is vulnerable to go bad and got rotten compared to other fruits. Furthermore, it is difficult to maintain freshness due to the possibility of softening, discoloration and fungi (Lee et al., 2012). In this regard, developing improved storage and package techniques is needed to ensure maintaining quality and safety even just two to three days after harvest. In order to ensure improved quality and safety of strawberries and lettuce after harvest, the present study applied a modified atmosphere packaging (MAP) technology (Mostofi et. al., 2008). Going forward, it compared the quality and safety of the two products while being stored in a way that put them in an MAP-applied container and a plastic container at room temperature and 4 degree Celsius.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.56-66
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• 2023

Safety accidents are increasing, such as changes in groundwater levels due to construction work or natural influences, or ground cave-ins caused by soil runoff from old water supply and sewage pipes. In addition, underground facility management agencies must make efforts to improve the accuracy of underground information through continuous investigation and exploration in accordance with the Special Act on Enhanced Underground Safety Management. Accordingly, in this study, we defined the configuration of equipment and data processing method to collect 3D precise exploration underground facility information and developed 3D underground facility information collection technology to ensure accuracy of underground facilities. As a result of verifying the developed technology, the horizontal accuracy improved by an average of 6cm compared to the existing method, making it possible to acquire 3D underground facility information within the error range of the public survey work regulations.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.6-13
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• 2018

Utilizing the heat of cooling water discharge of coal-fired power plant, pipeline investment costs for businesses that supply heat to agricultural facilities near power plants increase in proportion to installation distance. On one hand, the distance from the power plant is a factor that brings difficulties to secure economic efficiency. On the other, if the installation distance is short, there is a problem of securing the heating demands, facility houses, which causes economical efficiency to suffer. In this study, the economic efficiency of 1km length of standard heat pipeline was evaluated. The sensitivity of the heat pipe to the new length variation was analyzed at the level of government subsidy, amount of heating demand and the incremental rate of pipeline with additional government subsidy. As a result of the analysis, it was estimated that NPV 131 million won and IRR 15.73%. The sensitivity analysis showed that NPV was negative when the length of heat pipe facility exceeded 2.6 km. If the government supports 50% of the initial investment, the efficiency is secured within the estimated length of 5.3 km, and if it supports 80%, the length increases within 11.4 km. If the heat demand is reduced to less than 62% at the new length of the standard heat pipe, it is expected economic efficiency is not obtained. If the ratio of government subsidies to initial investment increases, the elasticity of the new bloc will increase, and the fixed investment, which is the cost of capital investment for one unit of heating demand, will decrease. This would result in a reduction in the cost of production per unit, and it would be possible to supply heat at a cheaper price level to the facility farming. Government subsidies will result in the increased economic availability of hot plumbing facilities and additional efficiencies due to increased demand. The greater government subsidies to initial investment, the less farms cost due to the decrease in the price per unit. The results of the study are significant in terms of the economic evaluation of the effectiveness of the government subsidy for the thermal power plant heat utilization project. The implication can be applied to any related pilot to come.

• Fire Science and Engineering
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• v.17 no.4
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• pp.76-85
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• 2003

In this study, we write down the definitions, their causes and the techniques of analysis as a theoretical consideration of common cause failures, and investigate the limitation and the importance of the common cause failures by applying to the analysis on the fire protection as a representative safety facility. As you can know in the reliability analysis, most impressive cause is the malfunctions of pumping operations; especially the common cause failure of two pumps is dominant. In other words, it is possible to assess system-reliability as twice as actual without CCF From these, CCF is extraordinarily important and the results are highly dependent on the CCF factor. And although it would increase with multiple installations, the reliability are not defined as linear with those multiplications. In addition, the differences in results due to the models for analysis are not significant, whereas the various sources of data produce highly different results. Therefore, we conclude that the reliabilities are dependent on the quality of the usable data much better than the variety of models. As a result, the basic and engineering device for the preventions of CCF of the multiple facilities is to design it as reliably as to design the fire-water pump. That is to say, we must assess those reliabilities using PFD whether they are appropriate to SIL (Safety Integrity Level) which is required for the reliability in SIS (Safety Instrumented System). The result of the analysis on the reliability of the fire-water supply with CCF shows that PFD is 3.80E-3, so that it cannot be said to be designed as safely as in the level of SIL5. However, without CCF, PFD is 1.82E-3 which means that they are designed as unsafely as before.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.472-472
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• 2004

Numerous studies on urban groundwater have been carried out in many other countries. Urban groundwater shows a unique hydrologic system because of complex urban characteristics such as road pavement, sewers and public water supply systems. These urban facilities may change the characteristics of groundwater recharge but contaminate its quality as well. There have been several researches on urban groundwater in Seoul. Seoul has been industrialized very rapidly so that the city has large population. The recent population in Seoul amounts to more than ten millions, corresponding to a very high density of about 17, 000 people/km$^2$. Therefore, many factors affect the groundwater quality and quantity in Seoul. Nowadays, groundwater in Seoul is being extracted for construction, industrial use, and drinking and so on. There are 15, 714 wells in Seoul and its annual usage is 41, 425, 977m$^3$(in 2001). Therefore, systematic studies are needed to properly manage and use the groundwater in Seoul. The purposes of this study in progress are to identify geochemical characteristics of groundwater in Seoul and to determine the extent of groundwater contamination and its relationship with urban characteristics. For this study, groundwater was sampled from more than 400 preexisting wells that were randomly selected throughout the Seoul area. For all samples, major cations together with Si, Al, Fe, Pb, Hg For 200 samples among them, TCE, PCE, BTEX were also analyzed by GC. Our study shows that groundwater types of Seoul are distributed broadly from Ca-HCO$_3$ type to Ca-Cl＋NO$_3$ type. The latter type indicates anthropogenic contamination. Among cations, Ca is generally high in most samples. In some samples, Na and K are dominant. The dominant anions change widely from HCO$_3$ to Cl＋NO$_3$. The anion composition is considered to effectively indicate the contribution of distinct anthropogenic sources. In addition, major ions are positively proportional to total dissolved solid (TDS) except K and NO$_3$. Thus, we consider that TDS may be used as an effective indicator of the extent of pollution. However, the increase of TDS may result from increased water-rock interaction. To determine the extent of groundwater contamination, it is needed to figure out the baseline water quality in Seoul. Furthermore, detailed geochemical studies are required to find out pollution sources and their corresponding hydrochemical parameters.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.453-463
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• 2017

Due to the increase in the size of buildings and scale, the importance of construction engineering that reflects the constructability from the design stage of the project is increasing. Especially, engineering efforts related to facilities, equipment and construction methods for temporary work at the design stage can significantly contribute to improvement of constructability and project performance. The purpose of this study is to derive construction engineering tasks on temporary work at the design phase of the high-rise building projects. 27 preliminary tasks were firstly investigated through literature review and experts' group interview, and the necessity and importance analysis of each tasks were then performed based on questionnaire survey. Most of the tasks related to plans on structural framework and lifting equipment were analyzed as relatively more important ones. Lastly, 21 engineering tasks, which are classified into 5 factors, were proposed through factor analysis. The factors were determined as 1) structural framework, measurement and circulation, 2) lifting equipment and pumping, 3) space zoning, 4) water supply, 5) temporary facility, electric power supply and lighting. The results of this study can be used as basic data for establishing efficient work process of construction engineering on temporary work at the design phase.

• Journal of the Korean Society of School Health
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• v.2 no.1
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• pp.91-107
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• 1989

This study was designed to evaluate current level of school health practice in Chonbuk province and to analyze the relationship between school health practice and variables. All the subjects in this study were 140 schools themselves in Chonbuk province. Survey data was collected through the interviewed checklists from the widly accepted school health responsibilities of administration and practice and the direct observation by the interviewer. It was conducted from 1st of Nov. to 17 th of Dec, 1988. The major findings of this study are as follows: A. Level of school health practice was relatively low in score (Mean=64.5). $\cdot$ Healthful School Living -76.14 $\cdot$ School Health Service -71.29 $\cdot$ School Health Instruction -47.98 B. Strengths and Weakness field in School Health Practice. 1. Healthful School Living: Strengths: Waste disposal, Seating, Playground. Weakness: School site, Safety control. 2. School Health Service : Strenths : Health Appraisal, Follow up and Counseling. Weakness: Dental Health, Prevention and Control of Communicable Disease, Facilities and Equipment of Health Clinic. 3. School Health Instruction : Strength : None, Weakness : Program Organization, Curriculum Planning and Evaluation, Curriculum Content, Instructional Aids. C. Significance between degree of School Health Practice and Variables. 1. Healthful School Living : (1) Toilet : Area (p<0.001), No.of Class (p<0.001), School Nurse (p<0.05) (2) Water Supply : School Nurse (p<0.05) (3) Safety Control : School Nurse (p<0.05) 2. School Health Service : (1) Health Appraisal : School Nurse (p<0.05) (2) Follow up and Counseling : School Nurse (p<0.001) (3) Dental Health : Area (p<0.05), Level of School (p<0.05) (4) Prevention and Control of Communicable Disease : Level of School (p<0.001), School Nurse (p<0.05) (5) Emergency Care : Area (p<0.001), No. of Class (p<0.001), School Nurse(p<0.001) (6) Facilities and Equipment of Clinic : Level of School (p<0.001), No.of Class (p<0.001), School Nurse (p<0.001) 3. School Health Instruction: (1) Program Organization : No. of Class (p<0.05), School Nurse (p<0.001) (2) Curriculum Planning land Evaluation : School Nurse (p<0.001) (3) Instructional Aids : Level of School (p<0.001), School Nurse (p<0.05) Recommendation for the Improvement of School Health Practice are as follows : A. There should be further study to strengthen the school health practice, especially in the field of school health instruction. B. It is strictly required to employ and utilize school nurse at each school level not only for the school health service but also for the school health in struction. C. There should be much considerations about adequate size and easily accessible distance in school site.

• Journal of Environmental Impact Assessment
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• v.23 no.2
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• pp.75-87
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• 2014

In order to analyze environmental impact of livestock manure and organic fertilizers, this study investigated livestock-breeding and pollution loads, the status of individual and public livestock manure treatment facilities, and the status of production, supply and components of compost and liquid fertilizers in the Nonsan area. Also, on a trial basis, this study investigated the life cycle of the environmental impact of livestock manure and its organic fertilizers on stream, groundwater, and agricultural soil. The results are as follows. Firstly, were detected the range of $0.13{\sim}1.32{\mu}g/L$ of As, $0.004{\sim}0.467{\mu}g/L$ of Cd and $0.5{\sim}9.2{\mu}g/L$ of Pb as a harmful substances which show lower concentrations than person preservation criteria of water qualities and aquatic ecosystem. However, it is not clear that heavy metals affect environment such as stream, groundwater and agricultural soil. Secondly, this influence could change according to investigation time and treatment efficiency. As were detected large amounts of persistent organic pollutants(e.g. $14.24{\sim}38.47{\mu}g/L$ of acetylsalicylic acid, $1.17{\sim}2.96{\mu}g/L$ of sulfamethazine, and $2.25{\sim}174.09{\mu}g/L$ of sulfathiazole) in effluent from livestock farms and small amounts of sulfathiazole($ND{\sim}1.63{\mu}g/L$) in the stream, it is necessary to monitor POPs at individual and public livestock manure treatment facilities. However, significant environmental impact did not appear at groundwater and agricultural soil in the test area supplied with liquid fertilizers. These results could be applied to investigate the environmental impact of livestock manure through a comprehensive livestock manure management information system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.429-435
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• 2021

The integrated underground space map shows the underground facility(water supply, sewage, gas, electric power, communication, heating), underground structures (subway, underpass, underground walkway, underground parking lot, underground shopping mall, common ward), ground(drilling, coffin, geology) refers to a map constructed so that a total of 15 types of underground information can be checked at a glance on a three-dimensional basis. The purpose of this study is to develop a technology to correct the problem of curved surface processing and the unevenness of underground facility pipelines that occur in converting 2D underground facility data into 3D-based underground space integrated map(3D underground facility model). do it with. To this end, we first investigated and reviewed the domestic and foreign status of technologies that generate data on underground facilities based on three dimensions, and developed a surface correction algorithm and an unevenness correction algorithm to solve practical problems. Algorithms to verify the developed algorithm This applied correction program was developed. Based on the above process, the three-dimensional model of the underground facility could be produced identically to reality. This study is judged to have significance as a basic study to improve the utilization of the underground spatial integration map.