• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.507-512
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• 2005

This research focuses on the development and application of a method for the detection of m-toluate in soils using a genetically engineered bioluminescent bacteria, Pseudomonas putida mt-2 KG1206. KG1206 produces light by direct (m-toluate and benzoate) and indirect (toluene analogs) inducers. For detection of m-toluate in soil system, 9.9 mL strain was amended with 0.1 mL soil ethanol extractant. A high correlation ($r^2>0.97$) was observed between bioluminescence and m-toluate concentration. The unknown concentrations of m-toluate in soil samples were pre-determined using a method developed based on bioluminescence activity of strain with extracted inducers. Values between by LC analysis and bioluminescence activity show moderate statistical results. These results demonstrate the feasibility of recombinant bioluminescent microorganism, engineered to generate a quantifiable bioluminescence signal in response to specific pollutants, may serve as combined sensing and reporting tools in environmental monitoring.

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.31-41
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• 1997

Public concerns about hazardous health effect from the exposure to organic by-products of the chlorination have been increased. There are numerous studies reporting that chlorination of drinking water produces numerous chlorinated organic by-products including THMs, HAAs, HANs. Some of these products are known to be animal carcinogens. The purpose of this study was to estimate health risk of DBPs by chlorinated drinking water ingestion in Seoul based on methodologies that have been developed for conducting risk assessment of complex-chemical-mixture. The drinking water sample was collected seperately at six water treatment plant in Seoul at March, April, 1996. In tap water of households in Seoul, DBPs were measured wilfh the mean value of 36.6 $\mu$g/L. Risk assessment processes,. which include processes for the estimation of human cancer potency using animal bioassay data and calculation of human exposure, entail uncertainties. In the exposure assessment process, exposure scenarios with various assumptions could affect the exposure amount and excess cancer risk. The reference dose of haloacetonitriles was estimated to be 0.0023 mg/kg/day by applying dibromoacetonitrile NOAEL and uncertainty factor to the mean concentration. In the first case, human excess cancer risk was estimated by the US EPA method used to set the MCL (maximum contaminant level). In the second and third case, the risk was estimated for multi-route exposure with and without adopting Monte-Carlo simulation, respectively. In the second case, exposure input parameters and cancer potencies used probability distributions, and in the third case, those values used point estimates (mean, and maximum or 95% upper-bound value). As a result, while the excess cancer risk estimated by US EPA method considering only direct ingestion tended to be underestimated, the risk which was estimated by considering multi-route exposure without Monte-Carlo simulation and then using the maximum or 95% upper-bound value as input parameters tended to be overestimated. In risk assessment for Trihalomethanes, considering multi-route exposure with adopting Monte-Carlo analysis seems to provide the most reasonable estimations.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.304-311
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• 2010

Korea National Forest Inventory System has been adopting different cluster plot design and new equations to estimate growing stock volumes since 2006. These changes have resulted in volume estimations which show some difference from previous ones. This study is to find out the source of such difference. For this, relevant data was collected from 80 plots of 20 cluster samples according to the cluster plot design applied to 4th and 5th National Forest Inventory. Then growing stock volumes were estimated by using current and previous individual tree volume equations respectively. An investigation was made to detect whether such difference in volume estimates was originated from the changes in cluster plot design or from using different volume equations. T-test results showed that the difference from changes in cluster plot design was negligible. Instead, changes in volume equations had statistically significant effects in volume estimation. Since the volume estimation by the 5th National Forest Inventory would bring overestimation by applying different volume equations, all the volume estimations made prior to 2006 would require necessary modifications for international reporting.

• YAKHAK HOEJI
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• v.52 no.2
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• pp.137-146
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• 2008

Even though driving under the influence of drug (DUID) is a worldwide problem, we, Korea has no regulation system yet except for alcohol, and there are little cases reported related to DUID. In order to investigate the type of abused drugs for drivers in Korea, we tried to analyze controlled and non-controlled drugs in alcohol-positive blood samples. 275 whole bloods, which were positive for alcohol on the roadside test, were collected from the police for two months ($Nov.{\sim}Dec.$ 2006). The analytical strategy was constituted of three steps: First, alcohol in blood samples were confirmed and quantified by gas chromatography. Second, controlled drugs were screened by $Evidence_{investigator}\;^{TM}$ (Randox, U.K.) as preliminary test. It was based on immunoassay by biochip array analyzer. Nine groups of drug abuse were screened: amphetamines, methamphetamines, cannabis, cocaine, opiates, barbiturates, methadone, benzodiazepines I (oxazepam) & II (lorazepam). Finally, confirmation of these drugs was performed by GC-MS. Blood samples were extracted by solid-phase extraction by $RapidTrace^{TM}$ (Zymark, U.S.A.). After trimethylsilyl (TMS) derivatization, eluates were analyzed to GC-MS. Total 49 drugs were investigated in this study including controlled drugs, antidepressants, 1st generation antihistamines, dextromethorphan, nalbuphine, ketamine, etc. For rapid detection, we developed the automated identification system. It was made up a new software, "DrugMan", modified Chemstation data analysis menu and newly developed macro modules. A series of peak selection, identification and reporting of the results were performed automatically by this system. Concentrations of alcohol in 275 blood samples were ranged from 0.011 to 0.249% (average, 0.119%). Among 149 blood samples, just six samples (4.0%) were showed positive results to the immunoassay: one methamphetamine and five benzodiazepines group I. By GC-MS confirmation, only benzodiazepines were detected and methamphetamine was not detected from immunoassay positive blood sample. Besides these drugs, 5 chlorpheniramines, dextromethorphan, diazepam, doxylamine, ibuprofen, lidocaine and topiramate were also detected in whole bloods by GC-MS. Conclusively, the frequency of drug abuse for Korean drivers was relatively low. There was none case which illegal drug was detected. However these results were limited to alcohol positive blood samples, so it is necessary to analyze more samples including alcohol negative blood.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.70-81
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• 2020

Point-by-point data, which is abundantly collected by vehicles with embedded GPS (Global Positioning System), generate useful information. These data facilitate decisions by transportation jurisdictions, and private vendors can monitor and investigate micro-scale driver behavior, traffic flow, and roadway movements. The information is applied to develop app-based route guidance and business models. Of these, speed data play a vital role in developing key parameters and applying agent-based information and services. Nevertheless, link speed values require different levels of physical storage and fidelity, depending on both collecting and reporting intervals. Given these circumstances, this study aimed to establish an appropriate collection interval to efficiently utilize Space Mean Speed information by vehicles with embedded GPS. We conducted a comparison of Probe-vehicle data and Image-based vehicle data to understand PE(Percentage Error). According to the study results, the PE of the Probe-vehicle data showed a 95% confidence level within an 8-second interval, which was chosen as the appropriate collection interval for Probe-vehicle data. It is our hope that the developed guidelines facilitate C-ITS, and autonomous driving service providers will use more reliable Space Mean Speed data to develop better related C-ITS and autonomous driving services.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.111-118
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• 2020

This study conducted an empirical analysis of SSE-listed companies to verify the effects of evaluation and disclosure of internal control systems on the agency costs management and controlling shareholders. Agency costs can affect the valuation of accounting information as asymmetry of information in the relationship between a company and its stakeholders, or induce financial costs as an adverse selection. If the firm's agency costs are reasonable, the valuation of the company can also move in a relatively positive direction. In this study, the evaluation information of the internal control system was analyzed through sales management ratio and equity ratio as substitute variables to analyze the relationship between management and agent costs of the controlling shareholders. In addition, independent control ratio, capital balance ratio, and company scale were used as control variables, as a result of the analysis, the evaluation information of internal control was found to be related to the agency costs of managers and governance structure. This study can be conducted to positive factors in evaluating the reliability and corporate value of accounting information according to the evaluation of internal control of SSE-listed companies and helps to understand the financial reporting environment.

• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.1047-1057
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• 2016

The purpose of this study was to examine if high risk drinkers are different from normal drinkers in terms of drinking motives, drinking refusal self-efficacy, and alcohol outcome expectancy. A total of 139 university male students in D area completed a self-reporting questionnaires to assess general characteristics, drinking motives, drinking refusal self-efficacy, alcohol outcome expectancy, and amount of drinking. The subjects were divided into high risk drinking and normal drinking based on a CDC guideline. The results of study show that high risk drinking group has higher odds for current smoking (adjusted OR=2.95, 95% CI [1.08, 8.05]), psychology major (adjusted OR=3.79, 95% CI [1.05, 13.71]), and enhancement motives (adjusted OR=2.64, 95% CI [1.15, 6.09]), whereas lower odds for junior grade (adjusted OR=0.21, 95% CI [0.05, 0.96]) and drinking refusal self-efficacy in social pressure (adjusted OR=0.42, 95% CI [0.24, 0.73]). The results suggest that drinking educational nursing intervention and smoking cessation program for university students are necessary to prevent high risk drinking effects.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.318-323
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• 2012

Implant prostheses were classified into screw-retained prosthesis and cement-retained prosthesis by their method of retaining, and there is screw and cement retained implant prosthesis (SCRP) which has been made reflecting the strengths of these two. The advantages of the SCRP technique are easy retrievability and passive fit of implant prostheses. However, the occlusal screw holes of implant prostheses can be thought as a disadvantage with respect to esthetics and occlusion. Inappropriately positioned implants also limited the use of the SCRP technique. The present study is reporting about the case where nine implants (US II, OSSTEM, Seoul, Korea) were placed in maxilla and eight in mandible respectively in fully edentulous patients. Then, the cement-retained prosthesis was applied for the part in which the screw hole positioned improperly, and screw-retained prosthesis for properly positioned implants so that the combined screw-cement prosthesis has been produced where the satisfying result has shown in both function and esthetics. Three-year follow-up has been done for the patient.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.7-14
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• 2008

Purpose: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. Materials and Methods: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. Results: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. Conclusion: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.189-197
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• 2013

The Cancun Agreements under the United Nations Framework Convention on Climate Change require developing countries aiming to undertake REDD+ activities to develop a national strategy or action plan, addressing the drivers of deforestation and forest degradation, a measurement, reporting and verifying (MRV) system including forest monitoring system, and safeguards to ensure equity and co-benefits for local communities and indigenous peoples, and biodiversity. The Government of Indonesia and the Government of Norway established REDD+ cooperation through signing a 'Letter of Intent' in May, 2010. Indonesia agreed on 'a two year suspension on all new concessions for conversion of peat and natural forest'. In turn, Norway agreed to support Indonesia's REDD+ implementation efforts up to one billion United States dollars. Indonesia's REDD+ national strategy (June, 2012) accepted most of the requests included in the 'Letter of Intent'. The REDD+ national strategy, however, does not reflect requests of the Cancun Agreements which noted identification of the drivers of deforestation and forest degradation and guarantee of real greenhouse gas emissions reductions. Indonesia lays emphasis on Norwegian requests which includes expected financial support rather than the Cancun Agreements which have a weak legally-binding requirements.