• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.2
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• pp.133-140
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• 2008

In order to evaluate the possible environmental lead hazard in children's playground and to test the practicability of field portable x-ray fluorescence(FPXRF) for environmental lead measurement, authors investigated lead concentration of lead-based paint on the surface of children's playing equipments in the playground of 13 apartments using FPXRF at the site in city A, Choongnam province. 93 spots were determined surface lead concentrations 3 times each using a FPXRF. Out of 93 spots, 83 spots (92%) were revealed to have lead in paint and mean concentration was $1.12{\pm}1.76mg/cm^2$. The mean concentration of lead on the surface of playing equipments at the apartments near the main street was $1.20mg/cm^2$ and higher than those at the apartments far away from the main street($0.81mg/cm^2$)(p<0.05). The mean concentration of lead on the surface of playing equipments painted with yellow color was $3.23mg/cm^2$ and the highest among all colors, whereas equipment painted white color was non-detectable. PVC and etc materials for construction of playing equipment showed higher surface lead concentration than other materials. The result suggests that it is necessary to be taken caution of the lead exposure in the playground of apartment and it should be taken any kind of confirmative action to prevent unwanted lead exposure from surface lead source of playing equipment. Authors found that FPXRF was very reliable and useful for field measurement to detect lead on the painted surface.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.186-198
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• 2000

The quality of the management of sanitation in food service establishments (school lunch programs, hospital patient food services, and commercial catering food services) in Korea was reviewed and evaluated, and ten strategies fur future improvement were suggested. They were: (1) An increase of qualified manpower and improvement of the professional training of the staff; (2) Obtaining special facilities exclusively for food service; (3) Improvement of facilities especially the kitchens; (4) Improvement of policy fur procuring raw materials and being assured of their quality by designing some standards and specifications for the raw materials to be purchased; (5) Production and use accurate and reliable kitchen apparatus and instruments; (6) An increase of the laboratory apparatus and instruments for inspection and evaluation of the sanitary level of raw materials and food service environments; (7) Enforced improvement of personal hygiene of the staff; (8) Use of a variety of methods in sanitary education and training; (9) Actively inspect the quality of imported foods; (10) Strengthening the research and accumulation of background data regarding sanitation management. There is a long process from the production of food to eating. The cooking process is the ultimate end of preparation of food before eating. This process sometimes increases the occurrence of food-borne diseases if we mishandle the food, even we obtained safe food. The process can also remove health hazards and reduce the risk from the hazards if we handle the food well although we have unsafe foods. This means the cooking process is a major key to preventing food-borne diseases. The concepts of hazard analysis critical control point (HACCP) should be applied and practiced in food service establishments in Korea as soon as possible.

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.77-95
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• 1986

In 1962 the governing bodies of FAO and WHO approved the establishment of a joint FAO/WHO Food Standards Programme, the creation of a jointly sponsored body to be known as the Codex Alimentarius commission to implement the Programme. It can reasonably be claimed that the Commission has assumad the leading role in establishing internation food standards throughout the world. The Codex Committee of Food Hygiene has received much advice and assistance from other international organization which have been working in this field for a number of years. In particular, it has received valuable background documentation from the International Commission on Microbiological Specifications for Foods(ICMSF) which was set up by the International Association of Microbiological Societies(IAMS), and also from the International Organization for Standardization (ISO). Nevertheless, in spite of the information supplied by governments and research bodies in this field, microbiological standards have proved to be a highly controversial subject from the point of view of Codex standards. When it is decided to establish a microbiological standard for a food or class of foods, the following technical and administrative aspects must be considered: 1) The standard should be based on factual studies and serve one or more of the following objectives: (1) to determine the conditions of hygiene under which the food should be manufactured; (2) to minimize the hazards to public health; (3) to measure the keeping quality and storage potential of the food 2) The standard should be attainable under practicable operating and commercial conditions and should not entail the use of excessive heat treatment or the additions of extra preservatives. 3) The standard should be determined after investigation of the processing operation. 4) The standard should be as simple and inexpensive to administer as possible, the number of tests being kept to a minimum. 5) Details of methods to be used for sampling, examining and reporting should accompany all published microbiological standards. 6) In establishing tolerance levels for the permissible number of defective samples, allowance should be made for sampling and other variations due to differences in the laboratory methods. The following additional points should be kept in mind: 1) It is not satisfactory to establish one set of microbiological standards for a miscellaneous group of foods, such as“frozen foods”or“precooked foods”. 2) Microbiological standards should be applied first to the more hazardous types of food on the basis of experience of expected microbiological levels, taking into account variations in composition, processing procedures, and storage. 3) When a standard is established, there should be a definite relationship between the standard and the hazard against which it is meant to protect the public. 4) The sensitivity, reliability, and reproducibility of the sampling and analytical methods should be compared in different laboratories and the methods to be used should be specified in detail as part of the standard. 5) Tolerances should be included in the standard to account for inaccuracies of sampling and analysis. 6) Standards should be applied on a voluntary basis before compliance is made mandatory.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.200-207
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• 1991

Jariieot is a local food prepared by fermentation of salted fish, Chromis notatus. Since its NaC' content is around 20% like other fermented seafoods, reduction NaCl concentration is desirable to minimize the risk of health hazard. Addition of KCl and enrichment of lactic acid fermentation were attempted to solve the problems resulting from low salt concentration. NaCl and KCl were added to a fish, Chromis notatus simultaneously at concentrations of 10 to 4% and 5 to 2%, respectively. Lactic acid bacteria and glucose at final concentration of 2% were also mixed with the above-salt treated fish to prepare jarijeot. The jarijeot was examined periodically for chemical changes during aging and compared with reference jarijeot containing only 20% of NaCl to find out an appropriate method for quality improvement. The content of ATP and its related compounds was not affected by the concentration of NaCl or the presence of lactic acid bacteria. Nearly no difference in contents of free amino nitrogen, trimethylamine oxide, trimethylamine and volatile basic nitrogen was observed between the jarijeot containing 20% of NaCl only and that containing 10% of NaCl, 5% of KCl, 2% of glucose and cells of Pediococcus halophilus. Moreover, sensory evaluation of both kinds of jarijeots revealed almost the same scores. The number of cells of P. halophilus was maintained at concentration of $10^5$cell/ml for 60days' fermentation in the above mentioned jarijeot containing 10% of NaCl. Its pH was dropped down to 4.2. Accordingly it is possible to prepare jarijeot enriched with lactic acid bacteria if KCl and glucose are added at concentration of 5% and 2%, respectively, in addition to NaCl at a final concentration of 10%.

• The Journal of Engineering Geology
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• v.25 no.1
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• pp.115-129
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• 2015

The cut-slope of a large-sectional tunnel portal is recognized as a potential area of weakness due to unstable stress distribution and possible permanent displacement. This paper presents a case study of a slope failure and remediation for a large-scale cut-slope at a tunnel portal. Extensive rock-slope brittle failure occurred along discontinuities in the rock mass after 46 mm of rainfall, which caused instability of the upper part of the cut-slope. Based on a geological survey and face mapping, the reason for failure is believed to be the presence of thin clay fill in discontinuities in the weathered rock mass and consequent saturationinduced joint weakening. The granite-gneiss rock mass has a high content of alkali-feldspar, indicating a vulnerability to weathering. Immediately before the slope failure, a sharp increase in displacement rate was indicated by settlement-time histories, and this observation can contribute to the safety management criteria for slope stability. In this case study, emergency remediation was performed to prevent further hazard and to facilitate reconstruction, and counterweight fill and concrete filling of voids were successfully applied. For ultimate remediation, the grid anchor-blocks were used for slope stabilization, and additional rock bolts and grouting were applied inside the tunnel. Limit-equilibrium slope stability analysis and analyses of strereographic projections confirmed the instability of the original slope and the effectiveness of reinforcing methods. After the application of reinforcing measures, instrumental monitoring indicated that the slope and the tunnel remained stable. This case study is expected to serve as a valuable reference for similar engineering cases of large-sectional slope stability.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.170-176
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• 2018

Laboratory inspection and diagnosis is a means of investigating and assessing various hazards or the state of research equipment in a laboratory, then taking appropriate safety measures to prevent accidents and injury. In many cases, laboratory inspection and diagnosis carried out by agencies are performed in a perfunctory manner that only barely satisfies the legal requirements. The aim of the present study is to provide clearly established pricing criteria for laboratory inspection and diagnosis, so as to prevent recurrence of laboratory accidents and to establish a safe laboratory environment. In order to clarify previously unclear matters, such as the lower limit for bids submitted by laboratory inspection and diagnosis agencies, technical manpower requirements, and number of laboratories inspected and diagnosed per day, a questionnaire survey was administered to agency personnel. First, when asked what the lower limit for bids submitted by agencies should be in order to improve reliability of inspection and diagnosis results and make up for the shortcomings of the lowest-bidder-wins system, 85.5% of respondents answered that the lower limit for bids should stand at no lower than 90% of the estimated price. The level of technical expertise among the technical personnel committed to laboratory inspection and diagnosis was shown to impact the reliability of results, and questionnaire results indicated a need to vary technical expertise levels depending on the degree of hazard, substances handled, and equipment used in a given laboratory. Level of technical expertise(67.1%) and number of personnel(52.6%) were shown to have a greater impact on reliability of diagnosis than on reliability of inspection. According to the results, it is determined that three persons(specialist, advanced and intermediate) should be committed to inspections, while four persons(professional, specialist, advanced and intermediate) should be committed to diagnoses. The respondents indicated a larger number of laboratories could be inspected than diagnosed per day. This can be attributed to differences in the amount of work each task involves, and the time each task takes. Assuming a six-hour work day not counting transportation, paperwork and rest, it is thought that inspection of up to 36 laboratories will be possible if each laboratory is assigned no more than 10 minutes(34.7%), while up to 24 laboratories could be inspected and diagnosed if each laboratory is assigned 15 to 20 minutes(35.1%).

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.642-648
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• 2019

Vessels sail according to the COLREG to prevent a collision. However, it is difficult to apply COLREG under special situation as heavy traffic, at this time personal skills of the operator are required. In this case, traffic control is required through the maritime traffic monitoring system. Therefore, maritime traffic management is globally implemented by VTS. In this system, VTS of icer uses the VTS system to assess risks and recommends possible safety operation to vessels with radio systems. This study considers that the risk analysis method with AI (Artificial Intelligence) technology from the operator's aspect. In addition, the research explains the Maritime Traffic Safety Monitoring System, Including AR (Augmented Reality) technology to increase vessel control efficiency. This system is able to predict hazards and risk priorities, and it leads to sequential elimination of dangerous situations. Especially, the hazard situations can be analyzed from operator's perspective of each vessel instead of the VTS officer's aspect, which is more practical than the conventional method. Furthermore, the result of analysis enables to comprehend quantitative hazardous areas and support recommended routes to avoid a collision. As a result, I firmly believe that the system will support to prevent a collision in complex traffic waters. In particular, it could be adopted as a collision prevention system for Maritime Autonomous Surface Ship, which occupies a significant proportion in Maritime 4th industrial revolution.

• Journal of Environmental Policy
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• v.11 no.4
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• pp.59-84
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• 2012

'Planning researchers' believe that losses from floods can be reduced if governments address this issue and adopt appropriate policies in their plan. As a starting point for examining this idea, this research assessed the ability of local government to incorporate flood mitigation policies in their local comprehensive plans using plan quality evaluation methodology. This study analyzed 53 local comprehensive plans in Florida against the protocol developed by including key flood mitigation policies. While flood mitigation through land use management tools, such as permitted land use in floodplain areas and wetland permit, gained widespread acceptance at the local level in Florida, incentive based tools/taxing tools and acquisition tools were rarely adopted. Study results show that 53 local plans in the sample received a mean score for total flood mitigation policy quality of 38.55, which represents 35.69 % of the total possible points. These findings indicate that there is still considerable room for improvement by local governments on flood issues. The scores of local plans varied widely, with coastal communities receiving significantly higher scores than non-coastal communities. Because the concept of the plan quality and its methodology offer an objective and straightforward tool for studying plan quality and guiding plan preparation, they can be applied to various environmental and hazard issues in Korea.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.39-47
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• 2003

Rockbursts are mainly caused by a sudden release or the stored strain energy in the rock mass. They have been the major hazard in deep hard rock mines but rarely occur in tunnels. Due to the short history and limited information on rockbursts, the topic has rarely been studied in Korea. Some cases of rockbursts, however, have been reported during construction of a mountain tunnel for waterway. This study focuses on analyzing data on rockbursts obtained from a TBM (Tunnel Boring Machine) tunnel and suggests methods for a comprehensive understanding on rockbursts. From the analysis of the field data of rockbursts, it was found that most rockbursts mainly occurred at the section between the tunnel face and the TBM operating room, and the rock bursting phenomena lasted up to 20 days after excavation in certain areas. The data also show that the bursting spots are located all around the tunnel surface including the face, the wall, and the roof, The maximum size of bursting spots is usually less than 100cm. This study also suggests new scale systems of brittleness and uniaxial compressive strength to evaluate the possible tendency for a rockburst. These systems are scaled based on the scale system of strain energy density. In addition, with these scale systems, this research shows that there are potentially higher tendencies for rockbursts in this specific tunnel. Moreover this research suggests that properties of rock and rock mass, RMR (Rock Mass Rating) value, tunneling method, excavating speed, and depth of tunnel have a strong correlation with rockbursts.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1377-1387
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• 2013

Most embankment of the reservoirs (99.1 %) have been constructed in the earth filled type in Korea because the construction of this type is less expensive and simpler than others such as concrete one. However, it has to be reinforced the slope to prevent the breach due to overtopping or piping under unexpected flood conditions. This study has been analyzed the retardation effect using three types (L, T, $L^*$ shape) of stiffener in order to reinforce embankment when they are collapsed by overtopping flow. Experimental results showed that L-type stiffener is the most effective in delaying the breaching of embankment and reducing the soil erosion when compared with others. The reinforced embankment breaching showed that time delay was occurred about 1.73 to 2.29 times and the peak flowrate was reduced compared to non-stiffener embankments due to energy dissipation by collision and less soil erosion. The embankment breaching mostly leads to major damages because of the lack of repair time. Thus, since these stiffeners can resist the rapid breach, it would be possible to earn the time to emergency repair and lifesaving, as well as reduction of damages of embankment in downward region with decreasing peak flowrate. Results from this study would be used for the basis when establishing the emergency action plan for the reservoirs on the verge of hazard.