• Korean Security Journal
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• no.42
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• pp.205-227
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• 2015

The Korean Peninsula is put in a position to carry out a highly strategic game vis-a-vis nK, which is asserting itself as a nuclear power amongst Northeast Asia's complex dynamics. While the international community recognizes nK's possession of nuclear weapons as released secret based on nK's three nuclear tests, shrewd strategic thinking is needed by ROK to secure itself as a non-nuclear nation in order to assume a responsible role to the international community, while simultaneously being ready to respond at all times for nK's military provocations. ROK must continue with its twofold strategy, by firm response to military confrontation with nK and maintaining flexible policy of tolerance in the areas of economy and ethnicity. Various strategic options to overcome nK's nuclear threats have been presented to ROK, whose possession of nuclear weapons have been difficult, and nK's nuclear capability is a real threat to ROK's national security. We must be able to respond to nK's nuclear threats strictly from ROK's national security perspective. This thesis aims to propose a response policy for nK's nuclear capability and nK's nuclear attack based on analysis of such nuclear damage, ROK Government's response posture against nK's nuclear threats, centered around ROK Government's non-military response posture.

• Journal of Soil and Groundwater Environment
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• v.6 no.3
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• pp.73-91
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• 2001

compounds (VOCs) were selected for assessment of VOCs contamination in some urban runoff and groundwater samples in Seoul. They included 3 aromatic hydrocarbons, 13 alkyl benzenes, 1 ether, 26 halogenated alkanes, 10 halogenated alkenes, and 9 halogenated aromatics. The levels of VOCs in urban runoff and groundwater were measured for samples collected in March 2000, June 2000 and November 2000 in Seoul City. A total of 78 samples (44 run-off water, 27 groundwater, and 7 samples from 4 urban wastewater treatment plants in Seoul) were collected and analysed by GC-MS with purge and trap. After examination of the runoff, it was concluded that alkyl benzenes and aromatic hydrocarbons were organic compounds which were significantly impacted by traffic flows in Seoul. Of 62 VOCs, only 11 VOCs were not detected in runoff samples, while 14 VOCs were detected in 27 groundwater samples. The toluene content in the runoff was extremely variable from 0.1ppb to 29,310ppb, depending on the different sampling sites. The concentrations of xylene ranged between 0.07ppb and 2970ppb in the runoff. The concentrations ranged from 0.05ppb to 33.0ppb for benzene, 0.05ppb to 960ppb for ethylbenzene, 0.08ppb to 20ppb for trichloromethane (chloroform) , 0.03ppb to 4.30ppb for trichloroethylene(TCE) and 0.1ppb to 50ppb for 1,1,2-trichloroethane. From the preliminary study of groundwater from some wells in Seoul, the most frequently detected VOCs are djchlorornethane(methylene chloride), trichloromethane(chloroform) and toluene. Most of aromatic hydrocarbons, alkyl benzenes and other solvents generally lower than detection limits.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.1
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• pp.38-45
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• 2017

Objectives: Radon may be second only to smoking as a cause of lung cancer. Radon is a colorless, tasteless radioactive gas that is formed via the radioactive decay of radium. Therefore, radon levels can build up based on the amount of radium contained in construction materials such as phospho-gypsum board or when ventilation rates are low. This study provides our findings from evaluation of radon gas at facilities and offices in an industrial complex. Methods: We evaluated the office rooms and processes of 12 manufacturing factories from May 14, 2014 to September 23, 2014. Short-term data were measured by using real-time monitoring detectors(Model 1030, Sun Nuclear Co., USA) indoors in the office buildings. The radon measurements were recorded at 30-minute intervals over approximately 48 hours. The limit of detection of this instrument is $3.7Bq/m^3$. Also, long-term data were measured by using ${\alpha}-track$ radon detectors(${\alpha}-track$, Rn-tech Co., Korea) in the office and factory buildings. Our detectors were exposed for over 90 days, resulting in a minimum detectable concentration of $7.4Bq/m^3$. Detectors were placed 150-220 cm above the floor. Results: Radon concentrations averaged $20.6{\pm}17.0Bq/m^3$($3.7-115.8Bq/m^3$) in the overall area. The monthly mean concentration of radon by building materials were in the order of gypsum>concrete>cement. Radon concentrations were measured using ${\alpha}-track$ in parallel with direct-reading radon detectors and the two metric methods for radon monitoring were compared. A t-test for the two sampling methods showed that there is no difference between the average radon concentrations(p<0.05). Most of the office buildings did not have central air-conditioning, but several rooms had window- or ceiling-mounted units. Employees could also open windows. The first, second and third floors were used mainly for office work. Conclusions: Radon levels measured during this assessment in the office rooms of buildings and processes in factories were well below the ICRP reference level of $1,000Bq/m^3$ for workplaces and also below the lower USEPA residential guideline of $148Bq/m^3$. The range of indoor annual effective dose due to radon exposure for workers working in the office and factory buildings was 0.01 to 1.45 mSv/yr. Construction materials such as phospho-gypsum board, concrete and cement were the main emission sources for workers' exposure.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.427-436
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• 2001

Objective : To estimate the prevalence of congenital heart disease from the 1990 student heart disease screening program. Methods : The heart disease screening program for elementary students was conducted in Kyonggi-do, in 1998. The subjects of the present study comprised the 40,402 students who attended the schools in the catchment area of a collaborative university hospital and who participated in the primary examination. The congenital heart disease (CHD) patients were initially identified through a questionnaire about prior medical history, and further through diagnostic tests & medical examinations in the secondary & the tertiary examinations. Certain assumptions were used in the estimation of the number of CHD cases among non-participants of the secondary & tertiary examinations. The overall prevalence of CHD was estimated by adding the CHD detection rates of the participants and the estimated prevalence of the non-participants. Results : Among the 40,402 primary participants, 1,655 were referred further, of whom 79.1% (1,309) participated in the secondary examination. Of these, 121 were referred to the tertiary examination, with a participation rate at this last stage of 80.2%. The positive predictive value (PPV) of the screening tools was the highest when the results of both EKG and the questionnaire were positive. Because 85.9% of the detected cases had a past history of CHD, PPV was higher when the selection criteria in the questionnaire included past CHD history than when it didnt. The CHD defection rate among the participants was 1.76 cases/1,000 and the presumed number of cases among the non-participants was 31; giving an estimated final CHD prevalence of 2.52 cases/1,000 (95% CI : 2.06-3.06). Among the identified cases of CHD, VSD (52.8%) was the most common, followed by PDA (9.7%), TOF (9.7%) & PS (9.7%). Conclusion : Because the characteristics of the non-participants differed from those of the participants, the estimation of prevalence was influenced by the participation rate. Of the detected cases, 85.9% had a past history of diagnosis or operation for CMD. These findings suggested that the prevalence estimated in this study may be an underestimation of the actual condition. Therefore, a birth cohort study is required in order to more accurately estimate the prevalence and the effects of the program.

• Journal of fish pathology
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• v.26 no.3
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• pp.129-137
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• 2013

The study surveyed infection rate of Kudoa septempunctata parasitized in the trunk muscle of olive flounder, Paralichthys olivaceus, cultured in Jeju Island and wild fish species caught in the coastal area around Jeju Island during 2012. Among 143 olive flounder that were randomly sampled from 26 different culture farms, K. septempunctata was detected in 7 fish samples (4.9%) from 4 different culture farms, showing no typical Kudoa infestation. However, K. septempunctata was not detected in olive flounder fry sampled from hatcheries and 8 species of wild fish. In addition, we compared 3 different sampling sites on trunk muscle of 7 Kudoa positive fish that included head part, tail part and entire muscle. Among 7 fish, K. septempunctata was detected in 3 fish that were sampled from head part; while 4 fish from tail part of trunk muscle. However, all 7 fish were positive when sampled from entire muscle. Thus, we suggest that it will be more efficient to use entire muscle sample than sampling partial muscle parts for detection of K. septempunctata.

• Anxiety and mood
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• v.6 no.1
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• pp.45-54
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• 2010

Objective : This study aimed to investigate and compare the prevalence of depression and suicidality among the elderly in a rural city according to their residence type. Methods : Participants were 311 elderly people (109 male and 202 female) in Icheon City, whom trained researchers interviewed and examined Geriatric Depression Scale, Social Support Scale, Instrumental Activities of Daily Living, Activities of Daily Living, Quality of Life Scale, and Mini International Neuropsychiatric Interview (MINI), module C. Using these data, we analyzed participants' risk factors associated with depression and suicidality. Results : The prevalence of depression was 28.0%. The prevalence in the elderly living alone and those admitted to residential facilities was significantly higher than that among the elderly living with family. Suicidality frequency was 19.6%. The suicidality frequency among the elderly living alone and those admitted to facilities was significantly higher than that among the elderly living with family. The risk factors for depression were age, admission to a facility, and low economic status. The suicidality risk factors were living alone, admission to a facility, poor social support, and a history of headache. Conclusion : These results showed the prevalence of depression and frequency of suicidality among the elderly in such a city was quite high. The results of this study remind psychiatrists of the importance of early detection and therapeutic intervention for the elderly with a high risk of depression and suicidality.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.39-50
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• 2001

Background: Power spectrum analysis method is a powerful noninvasive tool for quantifying autonomic nervous system activity. In this paper, we developed a data acquistion system for estimating the activity of the autonomic nervous system by the analysis of heart rate and respiratory rate variability using power spectrum analysis. Materials and methods: For the detection of QRS peak and measurement of respiratory rate from patient's ECG, we used low-pass filter and impedence method respectively. This system adopt an isolated power for patient's safety. In this system, two output signals can be obtained: R-R interval heart rate) and respiration rate time series. Experimental ranges are 30-240 BPM for ECG and 15-80 BPM for respiration. Results: The system can acquire two signals accurately both in the experimental test using simulator and in real clinical setting. Conclusion: The system developed in this paper is efficient for the acquisition of heart rate and respiration signals. This system will play a role in research area for improving our understanding of the pathophysiologic involvement of the autonomic nervous system in various disease states.

• Laboratory Medicine Online
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• v.7 no.3
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• pp.94-102
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• 2017

Malaria, tuberculosis, and hepatitis are common and notorious infectious diseases in Myanmar. Despite intensive efforts to control these diseases, their prevalence remains high. For malaria, which is a vector-borne disease, a remarkable success in the reduction of new cases has been achieved. However, the annual number of tuberculosis cases has increased over the last few decades, and the prevalence of chronic viral hepatitis infection has been high in Myanmar and other nearby countries. Early detection and prompt treatment are crucial to control these diseases. We have devoted our research efforts to understanding the status of these infectious diseases and working towards their eventual elimination for the last four years with the support of the Korea International Cooperation Agency. In the modern era, an infection that develops in one geographical area can spread globally because national borders do not effectively limit disease transmission. Our efforts to understand the status of infectious diseases in Myanmar will benefit not only Myanmar but also neighboring countries such as Korea.

• Korean Journal of Remote Sensing
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• v.15 no.1
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• pp.1-8
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• 1999

The estimation technique of surface water temperature by satellite remote sensing has been applied to ocean and large lakes using AVHRR. However, the spatial resolution AVHBR is not abquate for coastal region and small lakes. Landsat 5 TM has 120 m spatial resolution, which suits better. We carried out analysis of surface water temperature in Lake Sihwa and near coastal area using Landsat 5 TM. To relate digital number to the brightness temperature, we applied Empirical, NASA, RESTEC, Quadratic methods. Comparing calculated and observed value, we obtained as follows; NASA method, $R^2=0.9343$, RMSE(Root Mean Square Error)=3.5876$^{\circ}C$; RESTEC method, $R^2=0.8937$, RMSE=3.76$^{\circ}C$; Quadratic method, $R^2=0.8967$, RMSE=2.949$^{\circ}C$. Because Landsat TM has only one band for extracting surface temperature, it was difficult to correct for the atmospheric errors. For improving the accuracy of surface temperature detection using Landsat TM, there is a need for a method to decrease the effect of atmospheric contents.

• Korean Journal of Remote Sensing
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• v.16 no.3
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• pp.221-233
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• 2000

An intertidal topography is continuously changed due to morphodynamics processes. Detection and measurement of topographic change for a tidal flat is important to make an integrated coastal area management plan as well as to carry out sedimentologic study. The objective of this study is to generate intertidal DEM using leveling data and waterlines extracted from optical and microwave remotely sensed data in a relatively short period. Waterline is defined as the border line between exposed tidal flat and water body. The contour of the terrain height in tidal flat is equivalent to the waterline. One can utilize satellite images to generate intertidal DEM over large areas. Extraction of the waterline in a SAR image is a difficult task to perform partly because of the presence of speckle and partly because of similarity between the signal returned from the sea surface and that from the exposed tidal flat surface or land. Waterlines in SAR intensity and coherence map can effectively be extracted with MSP-RoA edge detector. From multiple images obtained over a range of tide elevation, it is possible to build up a set of heighted waterline within intertidal zone, and then a gridded DEM can be interpolated. We have tested the proposed method over the Gomso Bay, and succeeded in generating intertidal DEM with relatively high accuracy.