• Journal of Korea Water Resources Association
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• v.43 no.12
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• pp.1083-1091
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• 2010

Distributed hydrologic models typically require spatial estimates of precipitation interpolated from sparsely located observational points to the specific grid points. However, widely used estimation schemes fail to describe the realistic variability of daily precipitation field. We compare and contrast the performance of statistical methods for the spatial estimation of precipitation in two hydrologically different basins, and propose a two-step process for effective daily precipitation estimation. The methods assessed are: (1) Inverse Distance Weighted Average (IDW); (2) Multiple Linear Regression (MLR); (3) Climatological MLR; and (4) Locally Weighted Polynomial Regression (LWP). In the suggested simple two-step estimation process, precipitation occurrence is first generated via a logistic regression model before applying IDW scheme (one of the local scheme) to estimate the amount of precipitation separately on wet days. As the results, the suggested method shows the better performance of daily rainfall interpolation which has spatial differences compared with conventional methods. And this technique can be used for streamflow forecasting and downscaling of atmospheric circulation model effectively.

• The Journal of the Petrological Society of Korea
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• v.9 no.3
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• pp.142-168
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• 2000

The granites distributed in the Kyongsang basin contain the rocks which are different from the host rocks, and they are known as magic microgranular enclaves. The genesis of the magic micro-granular enclaves can be divided into four types: (1) rock fragments from country rocks; (2) cumulation of the early crystals in host magma or disruption of early chilled borders; (3) magma mingling; and (4) restite. These enclaves can be easily found in the granites around Mt. Wonhyo, Yangsan city. They are ellipsoidal in shape, and have phenocrysts might be originated from the host rocks and sharp contacts with the granites. Under the microscope, textures such as oscillation zoning, horn-blende-mantled quartz, rapakivi texture, and acicular apatite are observed, and these indicate that the enclaves were originated from magma and then produced by chilling. The evidences showing that the enclaves were formed by magma mingling are: (1) petrographical characteristics; (2) similarity of the compositions between the rim of plagioclase in the enclave and plagioclase in the granite; (3) linear trends of the major elements; (4) total REE content of the enclaves; and (5) Textural and compositional variations from rim to core in zoned enclaves. The magic end member of the enclave is regarded as the aphyric basaltic andesite in Mt. Sinbul-Youngchui area. The granites around Mt. Wonhyo experienced the magma mingling process which was produced by the injection of mafic magma at about 70 Ma, during the crystal differentiation, and then continued the crystallization. The equigranular granites and the micrographic granites in the study area are considered as the results after the magma mingling process.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.194-199
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• 2001

This study was designed to compare the effectiveness and applicability of the HApS$^{TM}$ (Hazard Analysis process System; HUKO, Seoul, Korea) based on Petrifilm$^{TM}$ (3M, St. Paul, MN, USA) with the AOAC (the Association of Official Analytical Chemists) standard total aerobic count (TAC) method and coliform count (CC) method for meat products. The comparisons were carried out using 230 meat samples collected from various retailers: 80 pork samples, 80 chicken samples, and 70 beef samples. In the comparison of the correlation coefficient (r) between conventional method and HApS$^{TM}$ method by a linear regression analysis, the correlation coefficients in total microorganism were 0.97767, 0.90712, and 0.95594 in pork, beef, and chicken samples, respectively. The correlation coefficients in coliform count were 0.82062, 0.94833, and 0.96839 in pork, beef and chicken samples, respectively. All the independent t-test on measurement values between conventional method and HApS$^{TM}$ method represented no significant differences in the means between two methods at the 0.05 of significance level($\alpha$=0.05). Based on the high correlation between HApS$^{TM}$ and the AOAC standard methods in the TAC and CC, it might be compatible to employ the HApS$^{TM}$ method to measure the microbial contamination in livestock products. HApS$^{TM}$ method was simpler and less time-consuming in sample preparation and procedures faster than the conventional method. These results suggested that the HApS$^{TM}$ method could be substitute for the conventional methods in the analysis of microbial contamination measurement in meat products.n meat products.

• Asian Journal of Atmospheric Environment
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• v.12 no.3
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• pp.255-273
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• 2018

To develop effective emission abatement strategies for eighteen coal-fired power plants located throughout Korea, power plant emission data and TAPM (The Air Pollution Model) were used to quantify the impact of emission reductions on primary $PM_{10}$ concentrations. TAPM was validated for two separate time periods: a high $PM_{10}$ concentration period from April 7 to 12, 2016, and a low $PM_{10}$ concentration period from June 1 to June 6 2016. The validated model was then used to analyze the impacts of five applicable power plant shut-down scenarios. The results showed that shut-down of four power plants located within the Seoul metropolitan area (SMA) would result in up to 18.9% reduction in maximum $PM_{10}$ concentrations, depending on synoptic conditions. A scenario for the shutdown of a single low stack height with highest-emission power plant located nearest to Seoul showed a small impact on averaged $PM_{10}$ concentrations (~1%) and 4.4% ($0.54{\mu}g/m^3$) decrease in maximum concentration. The scenario for four shutdowns for power plants aged more than 30 years within SMA also showed a highest improvement of 6.4% ($0.26{\mu}g/m^3$ in April) in averaged $PM_{10}$ concentrations, and of 18.9% ($2.33{\mu}g/m^3$ in June) in maximum concentration, showing almost linear relationship in and around SMA. Reducing gaseous air pollutant emissions was also found to be significant in controlling high $PM_{10}$ concentrations, indicating the effectiveness of coreduction of power plant emissions together with diesel vehicle emissions in the SMA. In addition, this study is implying that secondary production process generating $PM_{10}$ pollution may be a significant process throughout most regions in Korea, and therefore concurrent abatement of both gas and particle emissions will result in more pronounced improvements in air quality over the urban cities in South Korea.

• Journal of the Korean association of regional geographers
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• v.9 no.4
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• pp.461-480
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• 2003

This paper is to consider the new urbanization process of Daegu in the 1990s, especially with its economy, politics, social culture, environment and space. In the economic aspect, the industrial structure of Daegu has shifted from the manufacturing- centered economy to the service economy. But it has not yet overcome the linear frame of industrial structure still relying on the textile industry, though the degree of industrial specialization has increased in the part of the fabricated metal products and the precision and optical instrument. In the political situation that the implementation of the local self-government has made the relation between localities more competitive, the local government of Daegu has led a boom for boosting the regional economic growth, organizing private-public-research relations to improve the weakening regional investment and production function. In the social and cultural aspect of the new urbanization, the investment into the soft-ware facilities has been increased, and the urban festivals have been changed so as to revitalize the regional economy. In the environmental aspect, as the self-government system has launched, conflicts around values and interests of local governments have revealed frequently due to locations of infra-structures and of abhorrence facilities. Finally, seen from the spatial dimension of the city, the extension of residential areas and unregulated use of urban space have a result of inefficience of land-use, and this kind of unplanned outer expansion of the city has brought about with further separation of house and working place, and increasing distance of movements and the an urban spatial structure which requires more energy consumption.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.155-160
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• 1979

Mechanical agitation in fermentation process enhances the fermentation activity of microbes by means of oxygen supply and frequent collision with substrate. However, the fermentation activity of microaerophilic bacteria is inhibited by the excess oxygen resulted from the mechanical agitation. On this account, a a strain of Lactobacillus bulgarius was cultured to know the inhibition effect of the mechanical agitation and determine the optimum conditions for tile process of lactic acid fermentation. The growth rate of L. bulgaricus and the consumption rate of tile substrate revealed an identical pattern in changes. The two rates were constant in the range of the modified Reynolds number of $1\times10^5\;to\;5\times10^5$ while they showed linear increase in the range of the modified Reynolds number of $1\times10^5\;to\;10\times10^5$. Under the conditions of the modified Reynolds number more than $10\times10^5$, the both rates decreased. At the modified Reynolds number of $10\times10^5$, the maximum specific growth rate and the saturation constant of L. bulgaricus were 0.58/hr and 6.74g/l, respectively.

• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.519-530
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• 1998

In this paper, the basic study on the design of the flexible keel of the energy-storage prosthetic foot was performed in order to Improve the walking performance and Increase the activities of the below knee amputees. Based on the analysis of the anthropometric data and the normal gait on two dimensional sagittal plane available In the literature, we presented a model of the basic structure of the flexible keel of the prosthetic foot. The model of the basic structure was composed of the simple beams, and linear rotational spring and damper. Laminated carbon fiber-reinforced composites were selected as the material of the basic structure model of the flexible keel In order to apply the high strength and light weight materials to the basic structure of the flexible keel of the prosthetic foot. The recoverable strain energy In response to the change of beam shape was calculated bur the finite element analysis and it was suggested that the change of beam shape could be the design variable in flexible keel design. The simulation process was systematically designed by using orthogonal array table in order to design the flexible keel structure which could store the more recoverable strain energy. finite element analysis was carried but according to the design of simulations by using the finite element program ABAQUS and the flexible keel structure of the energy-storage prosthetic foot was obtained from the analysis of variance(ANOVA). The dynamic simulation model of the prosthetic walking using the flexible keel structure was made and the dynamic analysis was carried but during one walk cycle. Based on the above results, an effective design process was presented for the development of the prosthetic fool system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6413-6419
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• 2013

This study examined the irradiation effect of high energy x-rays on the hatching process of fertilized eggs, particularly with regard to malformation and blood cells change. The experimental groups were five day old fertilized eggs irradiated with x rays at doses of 5, 7.5, 10 Gyusing alinear accelerator. The control group was not irradiated. After three weeks, hatched chicks were sacrificed and examined for blood sampling. The survival rate of the x-ray irradiated groups were significantly lower than that of the control group (46.7vs 80%). The malformation rate of the experimental groups was60%, whereas no congenital malformations were observed in the control group. The experimental groups had a significantly higher malformation rate. The types of malformation were left wing defect, proptosis, microcephaly, cervical spine, and feet anomaly. The incidence of malformation increased with increasing radiation dose. The white blood cell count of control group and eachexperimental groups (5 and 7.5 Gy) were 87.64, 100.76 and 81.42 ($10^3/{\mu}L$), respectively. X-ray irradiation of 5 day old chick embryos increased the rate of death and malformation significantly.The malformations were estimated to have occurred by chromosomal abnormalities. Further genetic studies will be needed to confirm the correlation between high energy X-rays and the cause of malformations.

• Journal of the Korean Society of Safety
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• v.35 no.4
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• pp.64-73
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• 2020

As Korean government and safety-related organizations make continuous efforts to reduce the number of industrial accidents, accident rate has steadily declined since 2010, thereby recording 0.48% in 2017. However, the number of fatalities due to industrial accidents was 1,987 in 2017, which means that more efforts should be made to reduce the number of industrial accidents. As an essential activity for enhancing the system safety, accident analysis can be effectively used for reducing the number of industrial accidents. Accident analysis aims to understand the process of an accident scenario and to identify the plausible causes of the accident. Accident analysis offers useful information for developing measures for preventing the recurrence of an accident or its similar accidents. However, it seems that the current practice of accident analysis in Korean manufacturing companies takes a simplistic accident model, which is based on a linear and deterministic cause-effect relation. Considering the actual complexities underlying accidents, this would be problematic; it could be more significant in the case of human error-related accidents. Accordingly, it is necessary to use a more elaborated accident model for addressing the complexity and nature of human-error related accidents more systematically. Regarding this, HFACS(Human Factors Analysis and Classification System) can be a viable accident analysis method. It is based on the Swiss cheese model and offers a range of causal factors of a human error-related accident, some of which can be judged as the plausible causes of an accident. HFACS has been widely used in several work domains(e.g. aviation and rail industry) and can be effectively used in Korean industries. However, as HFACS was originally developed in aviation industry, the taxonomy of causal factors may not be easily applied to accidents in Korean industries, particularly manufacturing companies. In addition, the typical characteristics of Korean industries need to be reflected as well. With this issue in mind, we developed HFACS-K as a method for analyzing accidents happening in Korean industries. This paper reports the process of developing HFACS-K, the structure and contents of HFACS-K, and a case study for demonstrating its usefulness.

• Journal of the Korean Electrochemical Society
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• v.15 no.4
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• pp.216-221
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• 2012

Electrochemical reduction of carbon dioxide has been widely studied by many scientists and researchers. Recently, the production of formic acid, which is expensive but highly useful liquid material, is receiving a great attention. However, difficulties in the electrochemical reduction process and analyzing methods impede the researches. Therefore, it is important to design an adequate system, develop the reduction process and establish the analyzing methods for carbon dioxide reduction to formic acid. In this study, the production of formic acid through electrochemical reduction of carbon dioxide was performed and concentration of the product has been analyzed. Large scale batch cell with proton exchange membrane was used in the experiment. The electrochemical experiment has been performed using a series of metal catalysts. Linear sweep voltammetry (LSV) and chronoamperometry were performed for carbon dioxide reduction and electrochemical analysis using silver chloride and platinum electrode as a reference electrode and counter electrode, respectively. The concentration of formic acid generated from the reduction was monitored using high performance liquid chromatography (HPLC). The results validate the appropriateness and effectiveness of the designed system and analyzing tool.