• YAKHAK HOEJI
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• v.52 no.6
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• pp.419-425
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• 2008

A qualitative and quantitative analytical method was developed for detection of methamphetamine (MA) and its main metabolite amphetamine (AM) in oral fluid. Oral fluids of eleven drug abusers were provided by Police, specimens were collected by stimulation with a cotton swab treated with 20 mg of citric acid ($Salivette^{(R)}$; Sarstedt, USA). As the preliminary test, oral fluid samples were screened for amphetamines by Fluorescence Polarization Immunoassay (TDxFLx, Abbott Co.). Extraction for MA was performed using solid-phase extraction (SPE) by $RapidTrace^{TM}$ (Zymark, USA) with mixed mode cation exchange cartridge, CLEAN $SCREEN^{(R)}$ (130 mg/3 ml, UCT) after dilution with phosphate buffer. Samples were evaporated and derivatized by pentafluoropropionic acid anhydride (PFPA). Quantitation of MA and AM was performed by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring (SIM), the quantitation ions were m/z 204 (MA), 208 (MA-$D_5$), 190 (AM) and 194 (AM-$D_5$). The selectivity, linearity of calibration, limit of detection (LOD) and quantification (LOQ) within- and between day precision, accuracy and recoveries were examined as parts of the method validation. All oral fluid samples gave positive results to immunoassay for MA (cut-off level, 50 ng/ml as d-amphetamine). Concentrations of MA and AM by GC-MS in eleven samples were ranged 104.2${\sim}$4603.3 ng/ml and 32.4${\sim}$268.6 ng/ml, respectively. Extracted calibration curves of MA and AM were linear over the two concentration range of 1${\sim}$100 and 50${\sim}$1000 ng/ml with correlation coefficient of above 0.999. LOQ of MA and AM was 1 and 3 ng/ml, respectively. The intraand inter-day run precisions (CV) for MA and AM were less than 10%, and the accuracies (bias) for MA and AM were also less than 10% at the two different concentrations 5 and 100 ng/ml at low calibration range, 50 and 1000 ng/ml at high calibration range. The absolute recoveries of MA and AM at low and high calibration ranges were more than 82% and 75%, respectively. In this study the qualitative and quantitative analytical method of MA in oral fluid was established. Oral fluid testing may detect drug use in past hours because of its shorter detection window than urine, and be useful in post-accident situations. So oral fluids will be most useful for testing drug abuse in the driving under the influence of drug (DUID) as the alternative specimens of urine.

• Journal of the Health Care and Life Science
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• v.8 no.2
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• pp.155-163
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• 2020

The purpose of this study is to examine the current status of the Injury based on the 7th National Data on the National Health and Nutrition Survey, identify the relationship between general characteristics, safety awareness, health status, injury, and identify the factors that affect the occurrence of injury. The subjects were selected for the final analysis of 1,608data. For the analysis, frequency analysis, cross analysis, and multiple logistic regression analysis were performed. the results of the study show that in the young-old elderly, gender(woman), marital status(separated of divorced), lower the awareness of safety, body discomfort, sickness, and in-outpatient, Annual unmet medical service experienced are higher the occurrence of injury. Therefore, as a prevention education that lowers the incidence of injury. selective education is required for the Young-old and Old-old elderly, and legal penalties for drunk driving on various means of transportation and an integrated approach to strengthening and education is required.

• Informatization Policy
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• v.29 no.1
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• pp.84-102
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• 2022

Changes have been taking place in North Korea, which has been pushing for selective informatization with a priority on a system safety. North Korea has been developing its own mobile communication industry over the past decade by expanding base stations, producing smartphones on its own, and developing applications useful in real life. Recently, the introduction of 5G technology has been elevated to the status of a national agenda to be fostered as a key industry for national economic development. The time has arrived when the needs of North Korea, which has to advance technology, are aligned with the capabilities of South Korean mobile communication companies, which are seeking to new markets to overcome stagnant growth. The purpose of this paper is to illustrate a cooperative scenario for mobile communications companies between the two Koreas in the early stages of the 4th Industrial Revolution and its core technology 5G, while also making a timely proposal to position North Korea in the GVC. Mobile communications is a large-scale industry that can create synergies from inter-Korean economic cooperation by facilitating exchanges and cooperation between the two Koreas, inducing numerous derivative industries and driving job creation. Joint mobile communications activities with North Korea would be an effective cooperative aspect that can contribute to the economic prosperity of the entire Korean Peninsula.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.635-647
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• 2006

Korean construction companies first advanced to the international markets in 1960's and so far have brought more than 4,900 projects which account for 193 billion dollars approximately. With the large increase of national employment and income being followed by the achievement, Korea's construction industry has made an enormous contribution to the improvement of domestic economy for the last 40 years. However, recently the increased risk in international markets as well as the sharpening competition with foreign companies promising in terms of advanced technologies and low labor cost have been driving Korean construction away from the market shares. According to ENR (Engineering News Record, 1994~2003), it is revealed that 15.1% of top 225 global contractors are suffering from loss in international construction markets. This phenomenon is largely due to the highly uncertain characteristics of international projects, which are inherently exposed to various and complicated risky situations. Furthermore, especially for Korean construction companies, it is often the case that the failure in an international construction project cannot be offset by even a sufficient number of successful domestic achievements. Therefore, not only the selective screening among the nominated projects which have strong possibility of collapse but the systematic strategies for controlling potential risk factors are also considered indispensable in international construction portfolio management. The purpose of this study is to first analyze the causal relationships of the profit-influencing variables and the project success, and develop the profitability forecasting model in international construction projects.