• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.4
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• pp.477-487
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• 2019

Objectives: Firefighters are known to be exposed to a variety of toxic substances, but little information is available on the exposure profile of firefighting activities. The aims of this study were to conduct exposure monitoring of toxic chemicals at fire scenes, to compare the concentrations of respective chemicals among firefighting tasks, and to assess the main factors influencing the concentrations of chemicals. Methods: Researchers performed sampling at firefighting scenes during four weeks in 2013. At the scene, we collected samples based on firefighters' own activities and examined the situation and scale of the accident. Collected samples were classified into three categories, including fire extinguishing and overhaul, and were analyzed in the laboratory according to respective analysis methods. Results: A total of fourteen fire activity events were surveyed: five fire extinguishing, six overhaul, and three fire investigations. Although no substance exceeded the ACGIH TLV, PAHs were detected in every sample. Naphthalene ranged from 0.24 to 279.13 mg/㎥ (median 49.6 mg/㎥) and benzo(a)pyrene was detected in one overhaul case at 10.85 ㎍/㎥. Benzene (0.01-12.2 ppm) was detected in every task and exceeded the ACGIH TLV. No significant difference in concentrations between tasks was shown. Conclusions: These results indicate that all firefighting tasks generated various hazardous combustion products, including possible carcinogens.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.216-227
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• 2008

To understand eutrophication in the upper regions of brackish Lake Sihwa with a limited water exchange, temporal and spatial distributions of pollutants in water and sediment were investigated from March to October in 2005 and 2006. Also, pollution levels of water and sediment were estimated by trophic state index (TSI) and sediment quality guideline (SQG). Total nitrogen (TN), total phosphorus (TP), organic matter (COD), and chlorophyll $\alpha$ (Chl-$\alpha$) concentrations in the surface waters were largely varied temporally and spatially, and the variations were highest in the middle areas where strong halocline was formed. Chl-$\alpha$ concentrations in the middle area were very high in April (>$900\;{\mu}g\;L^{-1}$) when algal blooms (red tides) occurred. The relationships between TN and Chl-$\alpha$ (r=0.31), and TP and Chl-$\alpha$ (r=0.65) indicated that the algal growth was primarily affected by phosphorus rather than nitrogen. The distribution of COD was similar to that of Chl-$\alpha$, indicating that the autochthonous organic matters may be a more important carbon source, especially in the middle areas. The brackish water regions were classified as eutrophic or hypertrophic based on their TSI values ($69{\sim}76$). In addition, the content of nutrients (especially TP) in surface sediments were classified as severe polluted state, except the upper areas. Major causes of the eutrophication observed were probably due to high nutrients loading from watersheds, the phosphorus release from anaerobic sediment, and long retention time by the limited water exchange through the sluice gates.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.1-15
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• 2017

Daecheong Reservoir was made by the construction of a large dam (>15 m in height) on the middle to downstream of the Geum River and the discharge systems have the watergate-spillway (WS), a hydropower penstock (HPP), and two intake towers. The purpose of this study was to investigate the limnological anomalies of turbid water reduction, green algae phenomenon, and oligotrophic state in the lower part of reservoir dam site, and compared with hydro-meteorological factors. Field surveys were conducted in two stations of near dam and the outlet of HPP with one week intervals from January to December 2000. Rainfall was closely related to the fluctuations of inflow, outflow and water level. The rainfall pattern was depended on the storm of monsoon and typhoon, and the increase of discharge and turbidity responded more strongly to the intensity than the frequency. Water temperature and DO fluctuations within the reservoir water layer were influenced by meteorological and hydrological events, and these were mainly caused by water level fluctuation based on temperature stratification, density current and discharge types. The discharges of WS and HPP induced to the flow of water bodies and the outflows of turbid water and nutrients such as nitrogen and phosphorus, respectively. Especially, when hypoxic or low-oxygen condition was present in the bottom water, the discharge through HPP has contributed significantly to the outflow of phosphorus released from the sediment into the downstream of dam. In addition, HPP effluent which be continuously operated throughout the year, was the main factor that could change to a low trophic level in the downreservoir (lacustrine zone). And water-bloom (green-tide) occurring in the lower part of reservoir was the result that the water body of upreservoir being transported and diffused toward the downreseroir, when discharging through the WS. Finally, the hydropower effluent was included the importance and dynamics that could have a temporal and spatial impacts on the physical, chemical and biological factors of the reservoir ecosystem.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.47-56
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• 2014

Recently, the velocity of sea-level rising has increased due to the global warming and the natural disasters have been occurred many times. Therefore, there are various demands for the integration of vertical reference datums for the ocean and land areas in order to develop a coastal area and prevent a natural disaster. Currently, the vertical datum for the ocean area refers to Local Mean Sea Level(LMSL) and the vertical datum for the land area is based on Incheon Mean Sea Level(IMSL). This study uses 31 points of Tidal Gauge Bench Mark (TGBM) in order to compares and analyzes the geometric heights referring LMSL, IMSL, and the nationally determined geoid surface. 11 points of comparable data are biased more than 10 cm when the geometric heights are compared. It seems to be caused by the inflow of river, the relocation of Tidal Gauge Station, and the topographic change by harbor construction. Also, this study analyze the inclination of sea surface which is the difference between IMSL and LMSL, and it shows the inclination of sea surface increases from the western to southern, and eastern seas. In this study, it is shown that TGBM can be used to integrate vertical datums for the ocean and land areas. In order to integrate the vertical datums, there need more surveying data connecting the ocean to the land area, also cooperation between Korea Hydrographic and Oceanographic Administration and National Geographic Information Institute. It is expected that the integrated vertical datum can be applied to the development of coastal area and the preventative of natural disaster.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.395-401
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• 2010

This research was carried out as a survey on the contents of Lead (Pb) and Cadmium (Cd) in 5 type agricultural products unestablished safety guideline in Korea. The average levels of Pb: onion 0.010 mg/kg, cucumber 0.018 mg/kg, garlic 0.012 mg/kg, green pepper 0.027 mg/kg, sesame 0.029 mg/kg. The average levels of Cd: onion 0.006 mg/kg, cucumber 0.002 mg/kg, garlic 0.008 mg/kg, green pepper 0.011 mg/kg, sesame 0.024 mg/kg. The present result of this study showed that Pb and Cd contents in the whole samples were less than the maximum residual levels of the codex standard. The levels of exposure assessment for Pb and Cd by intake from vegetables and sesame were merely at $1.3{\times}10^{-4}$(mean) ~ $5.1{\times}10^{-4}$($95^{th}$ percentiles) ${\mu}$g/kg bw/day for Pb, $7.5{\times}10^{-5}$(mean) ~ $3.6{\times}10^{-4}$($95^{th}$ percentiles) ${\mu$}g/kg bw/day for Cd. The data from this research will be valuable source for database construction for science-based safety control and management for the trace metal contamination in food including agricultural products.

• Bulletin of the Society of Naval Architects of Korea
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• v.25 no.4
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• pp.69-80
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• 1988

This paper proposes simple formulae for buckling and ultimate strength estimation of plates subjected to water pressure and uniaxial compression. For the construction of a formula for elastic buckling strength estimation, parametric study for actual ship plates with varying aspect ratios and the magnitude of water pressure is carried out by means of principle of minimum potential energy. Based on the results by parametric study, a new formula is approximately expressed as a continuous function of loads and aspect ratio. On the other hand, in order to get a formula for ultimate strength estimation, in-plane stress distribution of plates is investigated through large deflection analysis and total in-plane stresses are expressed as an explicit form. By applying Mises's plasticity condition, ultimate strength criterion is then derives. In the case of plates under relatively small water pressure, the results by the proposed formulae are in good agreement compared with those by other methods and experiment. But present formula overestimates the ultimate strength in the range of large water pressure. However, actual ship plates are subjected to relatively small water pressure except for the impact load due to slamming etc.. Therefore, it is considered that present formulae can be applied for the practical use.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.226-245
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• 2019

Beopjusa Gwaebultaeng (Large Buddhist Painting), designated as Treasure No. 1259, was painted in 1766 and featured Yeorae (Buddha) at the center in the style of a single figure. It is the longest existing buddhist painting and was created by Duhun, a painter who was representative of 18th century Korean artists. His other remaining work is Seokgayeorae Gwaebultaeng (1767) in Tongdosa Temple. Considering their same iconography, they are assumed to have used the same underdrawing. Duhun had a superb ability to maintain a consistent underdrawing, while most painters changed theirs within a year. The Beopjusa painting carries significance because it was not only painted earlier than the one in Tongdosa, but also indicates possible relevance to the royal family through its records. Beopjusa Temple is also the site of Seonhuigung Wondang, a shrine housing the spirit tablet of Lady Yi Youngbin, also known as Lady Seonhui. Having been built only a year before Beopjusa Gwaebultaeng was painted, it served as a basis for the presumption that it has a connection to the royal family. In particular, a group of unmarried women is noticeable in the record of Beopjusa painting. The names of some people, including Ms. Lee, born in the year of Gyengjin, are recorded on the Bonginsa Temple Building, the construction of which Lady Yi Youngbin and Princess Hwawan donated money to. In this regard, they are probably court ladies related to Lady Yi Youngbin. The connection of Beopjusa Gwaebultaeng with the royal family is also verified by a prayer at the bottom of the painting, reading "JusangJusamJeonhaSumanse (主上主三殿下壽萬歲, May the king live forever)." While looking into the historical characteristics of this art, this study took an approach based on scientific analysis. Damages to Beopjusa Gwaebultaeng include: bending, folding, wrinkles, stains due to moisture, pigment spalling, point-shaped pigment spalling, and pigment penetration to the lining paper at the back. According to the results of an analysis of the painting pigments, white lead was used as a white pigment, while an ink stick and indigo were used for black. For red, cinnabar and minium were used independently or were combined. For purple, organic pigments seem to have been used. For yellow, white lead and gamboge were mixed, or gamboge was painted over white lead, and gold foil was adopted for storage. As a green pigment, atacamite or a mixture of atacamite and malachite was used. Azurite and smalt were used separately or together as blue pigments.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.556-569
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• 2015

With about 75% of the population of Korea criticizing the government's disaster policy and a failure to respond to large-scale emergency like the Sewol ferry sinking means that there is a deep distrust in the government. In order to prevent dreadful disasters such as the Sewol ferry sinking, it is important to secure a prime time with respect to disaster safety. Improving crisis management skills and managerial role of police officers who are in close proximity to the people is necessary for the success of disaster management. With disaster management as one of the most essential missions of the police, as a part of a national crisis management, a step by step strengthening of the disaster safety management system of the police is necessary, as below. First, at the prevention phase, law enforcement officers were not injected into for profit large-scale assemblies or events, but in the future the involvement, injection should be based on the level of potential risk, rather than profitability. In the past and now, the priortiy was the priority was on traffic flow, traffic communication, however, the paradigm of traffic policy should be changed to a safety-centered policy. To prevent large-scale accidents, police investigators should root out improper routines and illegal construction subcontracting. The police (intelligence) should strengthen efforts to collect intelligence under the subject of "safety". Second, with respect to the preparatory phase, on a survey of police officers, the result showed that 72% of police officers responded that safety management was not related to the job descriptions of the police. This, along with other results, shows that the awareness of disaster safety must be adopted by, or rather changed in the police urgently. The training in disaster safety education should be strengthened. A network of experts (private, administrative, and police) in safety management should be established to take advantage of private resources with regard to crisis situtions. Third, with respect to the response phase, for rapid first responses to occur, a unified communication network should be established, and a real-time video information network should be adopted by the police and installed in the police situation room. Fourth, during the recovery phase, recovery teams should be injected, added and operated to minimize secondary damage.

• Journal of the Korean association of regional geographers
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• v.7 no.1
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• pp.83-95
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• 2001

The purpose of this study is to examine that we can estimate land use by land values in 5 great cities. For this purpose, I calculated the percentage that each lot value makes up of the highest land values in the city as a indicator. I think this rate is very useful in the comparative study about many cities. At first, I set up four hypotheses based on my preceding studies. Hypothesis 1, the range of CBD can be estimated as having about 10% of the peak land values. Hypothesis 2, when the peak rate of concentric circle of land values seperated from CBD circle is about 30% of the peak land values, that is sub-CBD. Hypothesis 3, generally, a lot of having about 5% of the peak land values represents residential land commercial land use. Hypothesis 4, a lot of having about 3% of the peak land values represents only residential land use. The data on land values in five great cities were got from public notification on land values(1999) of the Ministry of Construction & Transportation. I selected highest lot values from many standard lot value in each Tong(the minimum administrative unit) in each cities. And I drew land values isopleth. Through that isopleth, I identified CBD cmd sub-CBD. Through the book of public notification on land values, I identified what land use are lots of having over 10%, about 5%, below 3% of the peak land values. As a result, we identified land use can be estimated by the percentage that each lot value makes up of the highest land values in the city. The bigger urban size becomes and the more stable land use becomes, the higher fitness of hypotheses becomes. The lowest degree of fitness about 4 hypotheses among 5 great cities showed in Inchon. Because Inchon lies adjacent to the greatest Seoul. The percentage that showed the lowest degree of fitness is 5% of the highest land values. The land use on lots of having about 5% of the peak land values is different from each other according to regional character in city.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.469-483
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• 2019

North Korea has experienced floods and sediment-related disasters annually since the 1970s due to deforestation. It is of paramount importance that technologies and trends related to forest restoration and soil erosion control engineering be properly understood in a bid to reduce damage from sediment-related disasters in North Korea, and to effect national territorial management following unification. This paper presents a literature review and bibliometric analysis including 146 related articles published in North Korea. First, we analyzed the textual characteristics of the articles. We then employed the VOSviewer software package to classify the research topic and analyzed this topic based on the time change. The results showed that articles on the topic have consistently increased since the 1990s. In addition, research related to soil erosion control engineering has been classified into four subjects in North Korea: (i) assessment of hazard area on soil erosion and soil loss, sediment related-disasters; (ii) hydraulic and hydrologic understanding of forests; (iii) reasonable construction of soil erosion control structures; and (iv) effects and management plan of soil erosion control works. The proportion of research related to the (ii) hydraulic and hydrologic understanding of forests had been significant during the reign of Kim Ilsung. However, the proportion of research related to the (i) assessment of hazard area on soil erosion and soil loss, sediment-related disasters, increased during the reign of Kim Jongil and Kim Jongun. Using these results, our analysis indicated that an interest in and need for soil erosion control engineering in North Korea has continually increased. The results of this study are expected to serve as a basis for preparing forestry cooperation between North and South Korea, and to serve as essential data for better understanding soil erosion control engineering in North Korea.