• Korean Journal of Community Nutrition
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• v.12 no.6
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• pp.854-863
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• 2007

This study was performed to compare nutritional supplementation habits for Korean professional soccer players with those for the non-athletic male adults. Information about prevalence and kinds of supplements taken, information sources, nutrition knowledge were collected. Data were obtained from 53 football players working for Korean professional football clubs and 44 non-athletic males, who answered a list of questionnaires which had been prepared in advance. The prevalence of supplement use in the soccer player group (96%) was strikingly higher than in the nonathletic male group (34%). Vitamins were taken most frequently, followed by red ginseng, multivitamin, Chinese medicine and amino acids supplements in the soccer player group, with each player taking 2.96 kinds of supplements in average. Multivitamin was the most popular supplement in the non-athletic male group. The major reason for taking supplements was not to feel and recover from fatigue in both groups. It appeared that the non-athletic males started to use supplements mostly by recommendation of friends or colleagues. Meanwhile, soccer players took supplements on their needs, with half of them (50.1%) provided with nutrition information. The most important information source was coaches for soccer players group, and mass media for the non-athletic male group. The average scores of soccer players group on basic nutrition and athletic nutrition were lower than the respective values of the non-athletic males. Among the soccer players, 68% had taken more than 3 kinds of supplements during the last year; nonetheless, more than half could not perceive the effectiveness of the supplements. Our results show that supplementation practices were widespread in soccer players, and suggest that nutrition education for proper use of supplements and overall health care is needed for soccer players.

• Journal of Korean society of Dental Hygiene
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• v.1 no.2
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• pp.181-192
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• 2001

The purpose of this was to evaluate the level of knowledge about Hepatitis B and AIDS among dental hygiene students at six dental hygiene educational programs in nationwide, compare the findings to those of Song's study. 1703 dental hygiene students surveyed by mail and answered a questionnaire, using the questionnaire used developed by DiClemente el al., on Hepatitis B vaccination, antibody production, experience of unintentional needle stick injuries, experience of surgical operation and blood transfusion, personal risk factors for HBV and HIV, management of HBV and HIV postexposure management et al. The data indicated that dental hygiene students (79.0%) in this study had more HIV vaccination than dental hygiene(74.3%) in Song's study. As for recognition of antibody production after Hepatitis B vaccination, only 34.6% of respondents answered they knew having antibody production and 95% of respondents knew not having antibody production. Over one-half of the respondents (55%) answered they didn't even recognize having antibody production. 52.3 percent of dental hygiene students experienced unintentional needle stick injuries. The findings on the knowledge about Hepatitis B and AIDS were that dental hygienists (76.5 points) received higher mean score than those of dental hygiene students (71.0 points) and that the distribution of right answer rate also showed wider range in dental hygiene students (27.7~97.5%) than those of dental hygienist (41.2~99.5%). There were no statistical differences among dental hygiene education programs. Finding of this study support that the curriculum of dental hygiene program should include instruction on sources and methods of transmission of infectious diseases, risk of virus transmission in the workplace and principles of infection control. Furthermore, infection-control practices should be utilized routinely and their application to dental personnel, management of HBV and HIV postexposure management. Furthermore, for preventing the further spread of infectious diseases (HBV, HIV and AIDS${\cdots}$) caused by bloodborne viruses, imposing an obligation rather than recommendation on Hepatitis B vaccination to all dental personnel and routinely utilizing infection-control guidelines for all dental patients in dental practices (include dental educational programs) should be accomplished by coordination the government agency.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.148-148
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• 2003

This study is to investigate the environmental levels and trend of dioxins, which was the 3$\^$rd/ year of environmental monitoring research for endocrine disrupting chemicals since 1999. Total 282 samples were analyzed from 115 sites including 26 sites of airs, 43 sites of waters, 11 sites of sediments and 35 sites of soil, which were the same as those of investigated sites in 2000. Sampling period was from June 2001 to June 2002. Target chemicals were seventeen species of 2,3,7,8-chlorine-substituted PCDD and PCDF congeners and were analyzed by the standard methods, established by National Institute Environmental Research (NIER). The average concentration of dioxins in air decreased from 0.324 pg-TEQ/N㎥ in 2000 to 0.287 pg-TEQ/N㎥ in 2001, and those in water and soil were 0.073pg-TEQ/L and 1.703pg-TEQ/dry g, respectively, which was the less values detected in 2000. In sediment, however, the value was 0.086pg-TEQ/dry g, which was the increase from the value of the year 2000. The concentration range of dioxins in air for 26 sites in 17 regions detected were 0.013∼l.664pg-TEQ/N㎥, 4 sites from those were exceeded the Air Quality Standards of Dioxin in Japan (0.6 pg-TEQ/N㎥). The tolerable daily intake of dioxins was calculated at the highest level (1.664) in air, with referring the soil and food data from Japan, was calculated to be 2.85pg-TEQ/kg/day, which was below the level of 4 pg-TEQ/kg/day suggested in KFDA(Korea). While the average concentration of dioxins in 15 big cities was 0.190 pg-TEQ/N㎥, that in 8 medium/small cities constituting an industrial complex was 0.558 pg-TEQ/N㎥. In water, the concentration range detected were 0∼0.946pg-TEQ/L and the trend of the average concentrations shows an increase from those of 1999 but decreased from those of 2000, any sites however were not exceeded the Water Quality Standards of Dioxin in Japan (1 pg- TEQ/L). In soil. the detected range were 0∼43.333 pg-TEQ/dry g and the average concentration decreased, compared with the results of 2000. According to the monitoring results by land utilization, the detected range were 0∼43.333pg-TEQ/dry g in farmland, 0.017∼0.601 pg-TEQ/dry g in the industrial area, 0.005∼0.049pg-TEQ/dry g in the park and 0.008∼1.825 pg-TEQ/dry g in the rest. In sediment, the detected range increased from 0∼0.244 pg-TEQ/dry g to 0∼0.537 pg-TEQ/dry g, based on the results of 2000. For the proper control of dioxins, continuous monitoring needs to be performed and in addition, the dioxin inventory should be prepared for major sources through the dioxin emission survey. These results would provide sound and solid basis for proper decision making of dioxins management like establishment of environmental quality standards in Korea.

• Environmental and Resource Economics Review
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• v.21 no.4
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• pp.921-945
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• 2012

Conditional Logit (CL) model is widely used since its model estimation and interpretation of results of the model is relatively easy, on the other hand, it has the limit of preference heterogeneity of respondents being not fully considered. In this study we used the two models, Mixed Logit (ML) Model and Latent Class Model (LCM) to explain preference heterogeneity of respondents for protection for Boryeong Dam wetland. As a result of the examination for heterogeneity in Boryeong city and six metropolitan areas, we found there was significant difference between two regions. While there was explicit preference heterogeneity within respondents in Boryeong city, we found little heterogeneity within respondents in six metropolitan areas. Thus in the case of six metropolitan areas, CL model can be used for parameter estimation while in the case of Boryeong city, WTP estimates are based on parameter estimates from ML model to reflect the heterogeneity within respondents. Additionally, ML model with interaction and 2-class LCM for respondents in Boryeong city were used to explain the sources of the heterogeneity. The ML model with interaction has advantage of explaining individual unobserved heterogeneity. However The comarison between these two models reflects the fact that LCM provided added information that was not conveyed in the ML model with interaction. Thus, Preference heterogeneity within respondents in this study may be better explained by class level through LCM rather than indiviual level through ML model.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.376-379
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• 2003

The aerial parts of tile Garland (Chrysanthemum comnarium L.) were extracted in MeOH and solvent fractionated with EtOAc, n-BuOH and water, successively. EtOAc fractions gave three steroid compounds through application of silica gel column chromatographies. The chemical structures of the steroids were determined by the interpretation of several spectral data, including NMR and MS as $stigmast-5-en-3{\beta}-ol\;(1,\;{\beta}-sitosterol),\;stigmast-4-en-6{\beta}-ol-3-one$ (2), $stigmast-4-en-6{\alpha}-ol-3-one$ (3). Compounds 2 and 3 have been so far reported only in the aquatic plants, were isolated for the first time from the land plants.

• Journal of Energy Engineering
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• v.26 no.2
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• pp.99-120
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• 2017

In SS branch of Korea District Heating Corporation, Combined Heat & Power power plant with 99MW capacity and 98Gcal / h capacity is operated as a district electricity business. In this region, it is difficult to operate the generator due to the problem of surplus heat treatment between June and September due to the economic recession and the decrease in demand, so it is urgent to develop an economical energy new business model. In this study, we will develop an optimized operation model by introducing a renewable energy hybrid system based on actual operation data of this site. In particular, among renewable energy sources, fuel cell (Fuel Cell) power generation which can generate heat and electricity at the same time with limited location constraints, photovoltaic power generation which is representative renewable energy, ESS (Energy Storage System). HOMER (Hybrid Optimization of Multiple Energy Resources) program was used to select the optimal model. As a result of the economic analysis, 99MW CHP combined cycle power generation is the most economical in terms of net present cost (NPC), but 99MW CHP in terms of carbon emission trading and renewable energy certificate And 5MW fuel cells, and 521kW of solar power to supply electricity and heat than the supply of electricity and heat by 99MW CHP cogeneration power, it was shown that it is economically up to 247.5 billion won. we confirmed the results of the improvement of the zone electricity business condition by introducing the fuel cell and the renewable energy hybrid system as the optimization process model.

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.431-446
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• 2018

In this study, chemical characteristics of $PM_{2.5}$ samples collected in an agricultural area in Nonsan of Korea were investigated focusing on of black carbon, 3 inorganic ions and 22 trace elements. It was found that the relative error and relative standard deviation of many trace elements fell below 10%, which indicates good analytical accuracy and precision. The mean values of $PM_{2.5}$ in an agricultural area were exceeded by new Korean air quality standard of March 2018. The concentration of $PM_{2.5}$ was well correlated with those of black carbon and ions. The concentrations of trace elements were in a wide range of seven orders of a magnitude. Based on these $PM_{2.5}$ data sets, a total of 6 sources were identified using PMF (Positive Matrix Factorization; secondary aerosol (34.4%), soil/road dust (20.1%), biomass burning (16.9%), incineration/fuel combustion (13.2%), vehicle exhaust(12.2%), sea-salt (3.17%). Results of our study indicate that it is very important to control illegal burning activities in agricultural area.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.118-124
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• 2007

The oceans could absorb almost all the anthropogenic carbon dioxide the mankind has been producing eventually, but in the nature the air-sea $CO_2$ exchange occurs very slowly and to lower the atmospheric $CO_2$ concentration substantially $CO_2$ must be injected to the interior of the ocean directly. If we inject $CO_2$ collected at the major $CO_2$ sources into the international waters in the Philippine Sea or east of Japan, we could store the $CO_2$ in the oceans effectively for a few hundred years. When $CO_2$ is dissolved into the water, PH drops. The creatures adapted to the deep oceans where environment is very stable could be affected by even a small change in pH significantly. If, therefore, we are to inject $CO_2$ into the oceans, we must assess the effect of $CO_2$ injection in the marine ecosystem beforehand. Only when the damage to the marine ecosystem is smaller than the benefit from the $CO_2$ injection, $CO_2$ injection is effective.

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.269-275
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• 2004

Different biological tissues have different values of electrical resistivity. In EIT (electrical impedance tomography), we try to provide cross-sectional images of a resistivity distribution inside an electrically conducting subject such as the human body mainly for functional imaging. However, it is well known that the image reconstruction problem in EIT is ill-posed and the quality of a reconstructed image highly depends on the measurement error. This requires us to develop a high-performance EIT system. In this paper, we describe the development of a 16-channel digital EIT system including a single constant current source, 16 voltmeters, main controller, and PC. The system was designed and implemented using the FPGA-based digital technology. The current source injects 50KHz sinusoidal current with the THD (total harmonic distortion) of 0.0029% and amplitude stability of 0.022%. The single current source and switching circuit reduce the measurement error associated with imperfect matching of multiple current sources at the expense of a reduced data acquisition time. The digital voltmeter measuring the induced boundary voltage consists of a differential amplifier, ADC, and FPGA (field programmable gate array). The digital phase-sensitive demodulation technique was implemented in the voltmeter to maximize the SNR (signal-to-noise ratio). Experimental results of 16-channel digital voltmeters showed the SNR of 90dB. We used the developed EIT system to reconstruct resistivity images of a saline phantom containing banana objects. Based on the results, we suggest future improvements for a 64-channel muff-frequency EIT system for three-dimensional dynamic imaging of bio-impedance distributions inside the human body.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.1
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• pp.125-132
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• 2017

Objective: Along with increasing livestock products via intensive rearing, the accumulation of livestock manure has become a serious issue due to the fact that there is finite land for livestock manure recycling via composting. The nutrients from livestock manure accumulate on agricultural land and the excess disembogues into streams causing eutrophication. In order to systematically manage nutrient loading on agricultural land, quantifying the amount of nutrients according to their respective sources is very important. However, there is a lack of research concerning nutrient loss from livestock manure during composting or storage on farms. Therefore, in the present study we quantified the nutrients from dairy cattle manure that were imparted onto agricultural land. Methods: Through investigation of 41 dairy farms, weight reduction and volatile solids (VS), total nitrogen (TN), and total phosphorus (TP) changes of dairy cattle manure during the storage and composting periods were analyzed. In order to support the direct investigation and survey on site, the three cases of weight reduction during the storing and composting periods were developed according to i) experiment, ii) reference, and iii) theoretical changes in phosphorus content (${\Delta}P=0$). Results: The data revealed the nutrient loading coefficients (NLCs) of VS, TN, and TP on agricultural land were 1.48, 0.60, and 0.66, respectively. These values indicated that the loss of nitrogen and phosphorus was 40% and 34%, respectively, and that there was an increase of VS since bedding materials were mixed with excretion in the barn. Conclusion: As result of nutrient-footprint analyses, the amounts of TN and TP particularly entered on arable land have been overestimated if applying the nutrient amount in fresh manure. The NLCs obtained in this study may assist in the development of a database to assess the accurate level of manure nutrient loading on soil and facilitate systematic nutrient management.