• 한국가스학회지
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• 제20권4호
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• pp.50-57
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• 2016

도시가스사업법령에서는 매설된 강관에는 부식을 방지하기 위하여 전기방식 조치를 하도록 하고 있다. 미국 등 국외에서 방식전위기준은 방식전류가 흐르는 상태에서 포화황산동 기준전극으로 -850 mV(On potential) 이하로 하도록 하고 있으며, 이 경우 전압강하(IR-Drop)를 고려하도록 하고 있다. 그러나, 국내의 방식전위 기준은 포화황산동 기준전극으로 -850mV 이하로 하도록 규정하고 있을 뿐, 전압강하를 고려하도록 규정하고 있지 않다. 다만, KGS GC202에서 가스시설에 대한 전위측정은 가능한 한 가스시설과 가까운 위치에서 기준전극으로 실시하도록 하고 있다. 본 연구에서는 기준전극을 매설배관 주위, 지표면 및 지표면 하부 50cm에 각각 설치하여 방식전위를 측정하고, 측정위치에 따른 전위값을 비교하여 전압강하를 분석하였다. 전위 측정결과 기준전극을 매설배관 가까이에 위치하였을 때 IR-Drop이 가장 적고, 지표면에 기준전극을 위치할 때 IR-Drop 값이 가장 큼을 확인하였다. 따라서, 고체기준전극을 매설하는 경우에는 가능한 한 매설배관 가까이에 설치할 것을 제안하였다. 또한, 기존에 설치된 배관의 원격전위 측정을 위해서는 기존에 설치된 전위측정용터미널(T/B) 하부에 고체기준전극을 매설할 수 있도록 전기방식 기준전극 설치 기준 개정(안)을 제시하였다.

• 한국재난정보학회 논문집
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• 제10권2호
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• pp.294-303
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• 2014

국가는 "헌법"에 따라 국민의 안전을 확보하고, 생명 신체에 대한 위험으로부터 국민을 보호할 의무가 있다. 우리나라와 같이 북한의 화생방전 공격의 위협이 있는 국가에서는 국가의 기본권 보호의무의 이행차원에서 국민의 생명 신체를 보호하기 위한 법제를 마련하여야 한다. 현행 법제를 검토한 결과 전시상태에서 적용되는 "통합방위법", "민방위기본법"등 전시관련법은 전시상황에서 발생하거나 발생할 우려가 있는 화생방위험으로부터 국민을 보호하기 위한 법제로 충분치 못하다. 그러므로 국가는 "화생방사태시 국민보호에 관한 법률"을 제정하여 전시 화생방위험으로부터 국민을 보호할 수 있는 체계를 구축하여야 한다. 이 논문은 이와 같은 결론을 도출하기 위하여, 전시사태에서 국민을 보호해야 하는 헌법상 국가의 보호의무의 이론적 논의, 화생방에 특수하게 국민보호조치가 필요한 이유와 이에 따른 입법적 정비방안의 방향 제시, "화생방사태시 국민보호에 관한 법률"의 다른 법률과의 관계와 이 법에 포함되어야 하는 사항을 정리하였다.

• 정보보호학회논문지
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• 제27권1호
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• pp.163-176
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• 2017

최근 주요기반시설은 기존의 폐쇄적인 환경에서 개방적인 환경으로 변화하고, 사이버공간으로 범위가 확장되면서 사이버위협의 새로운 대상이 되고 있다. 또한 정보통신기술의 발전으로 주요기반시설 간의 상호의존성이 증가하고 있다. 그러나 기존 연구는 동향조사 및 보호정책 논의 수준에 머물러, 정책의 효율적 추진을 위한 현황 진단 및 적절성 판단 등의 연구는 별도로 진행되고 있지 않다. 이에 본 연구는 기존에 국가별 사이버보안 수준을 측정하는 국제지표 3가지를 비교 분석하여 주요기반시설의 보호수준을 측정하기 위한 새로운 지표를 개발하고, 해당 지표를 통하여 미국과 일본, 영국, 독일, 노르웨이로 대표되는 주요국과 한국의 현재 주요기반시설의 보호수준을 측정한다. 이를 통하여 미래 사이버공간에서 한국의 영향력을 확대하고 국가 간 신뢰를 구축할 근거자료가 되기를 기대한다.

• Journal of Radiation Protection and Research
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• 제39권1호
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• pp.1-6
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• 2014

원전에서는 방사성핵종의 체내 섭취에 따른 작업종사자의 내부 방사능을 측정하기 위하여 전신계측기(WBC)를 이용하고 있다. 이 계측기는 인체 내 방사성핵종의 침적위치를 고려하여 다양한 측정 모드를 선택하여 측정할 수 있으나, 대부분 전신 모드를 적용하고 있다. 그런데 전신 모드를 적용한 내부방사능 측정값은 WBC 측정 모드 중에서 가장 보수적인 값을 나타내는 특성이 있고, 따라서 내부피폭 방사선량이 과대평가되는 문제점이 있다. 이러한 문제점을 해결하기 위해 WBC, 팬텀, 표준 방사선원을 이용하여 WBC의 측정 모드별 방사능측정 실험을 수행하였다. 이 결과에 대해 통계적 분석방법을 적용하여 WBC의 상부 및 하부 검출기 계측비율에 따라 WBC의 측정 모드를 선정할 수 있는 정량적인 기준을 제시하였다.

• Journal of Radiation Protection and Research
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• 제41권2호
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• pp.93-99
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• 2016

Background: Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. Materials and Methods: In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. Results and Discussion: In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. Conclusion: The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

• 대한미생물학회지
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• 제22권2호
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• pp.109-116
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• 1987

As a process to establish an effective preventive measure of V. vulnificus septicemia, bactericidal effect of distilled water against V. vulnificus was studied. When about $2.0{\times}10^7\;CFU/ml$ of V. vulnificus was inoculated in distilled water, a dramatic decrease in the number of viable bacteria by 5 to $6LOG_{10}$ was observed in 5 minutes. Bactericidal kinetic curves could be divided into the first rapid killing phase until 1 minute and the later slow killing phase after then, showing the heterogeneity of the bacterial population inoculated. When V. vulnificus was inoculated in saline solutions having various salinities, significant decrease in the number of viable bacteria was noted only at salinities under 0.2%. The higher was the concentration of NaCl, the greater was the degree of protection against osmotic shock. When glucose, NaCl, $MgCl_2$, and $CaCl_2$ were diluted with deionized water to give same osmolarities and V. vulnificus was inoculated in each of them to compare the bactericidal curves plotted during the first 5 minutes after inoculation, the protection efficiencies were in the order of $MgCl_2>CaCl_2{\gg}NaCl{\gg}glucose$. Above results indicate that treatment(or thorough washing) of contaminated sea animals or other products with distilled water can be used as a preventive measure of V. vulnificus septicemia, and divalent cations can protect V. vulnifcus to osmotic shock with high efficiency.

• 치위생과학회지
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• 제19권2호
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• pp.113-121
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• 2019

Background: We investigated somatization symptoms experienced by dental hygienists due to stress from emotional labor. Our aim was to provide basic research data that could be useful in the development of efficient stress management schemes for this occupational group. Methods: We analyzed data collected from 208 dental hygienists working in Jeollabuk-do Province, Korea. To measure the level and intensity of emotional labor among research participants, we used the Korean Emotional Labor Questionnaire. We used the Somatization Symptom Checklist-90-Revised (SCL-90-R) to measure the level of somatization symptoms among participants. Results: On analyzing the level of emotional labor and somatization symptoms according to general characteristics, participants aged 23~25 years showed high scores for stress due to emotional labor (p<0.05). Working 5 days per week, subjective health status, and organizational support and protection systems were found to correlate with the level of stress due to emotional labor (p<0.05). In the analysis of correlations between emotional labor and somatization symptoms, scoring high across all domains of emotional labor was associated with scoring high for somatization symptoms in the subdomains of emotional labor. When emotional labor and demographical variables were used as independent variables, having higher scores for emotional labor and having poor subjective health status were found to be associated with having higher levels of somatization symptoms (p<0.05). Conclusion: Our results showed that working at night and organizational support and protection systems were correlated with emotional labor and somatization symptoms. Measures must be taken at the organizational level to reduce emotional labor and somatization symptoms.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.3051-3058
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• 2022

In the present work, untreated Iraqi sand with grain sizes varied between 100 and 200 ㎛ was used to produce a colored glass sample that has shielding features against the low gamma-ray energy. Therefore, a weight of 70-60 wt % sand was mixed with 9-14 wt% B₂O₃, 8-10 wt% Na₂O, 4-6 wt% of CaO, 3-6 wt% Al₂O₃, in addition to 0.3% of Co₂O₃. After melting and annealing the glass sample, the X-ray diffraction spectrometry was applied to affirm the amorphous phase of the fabricated glass samples. Moreover, the X-ray dispersive energy spectrometry was used to measure the chemical composition, and the MH-300A densimeter was applied to measure the fabricated sample's density. The Makishima-Makinzie model was applied to predict the mechanical properties of the fabricated glass. Besides, the Monte Carlo simulation was used to estimate the fabricated glass sample's radiation shielding capacity in the low-energy region between 22.1 and 160.6 keV. Therefore, the simulated linear attenuation coefficient changed between 10.725 and 0.484 cm^-1, raising the gamma-ray energy between 22.1 and 160.6 keV. Also, other shielding parameters such as a half-value layer, pure lead equivalent thickness, and buildup factors were calculated.

• Journal of Radiation Protection and Research
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• 제48권3호
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• pp.131-143
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• 2023

Background: This study examined the detection limit of thyroid screening monitoring conducted at the time of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011 using a Monte Carlo simulation. Materials and Methods: We calculated the detection limit of a NaI(Tl) survey meter to measure ¹³¹I accumulation in the thyroid gland of children. Mathematical phantoms of 1- and 5-year-old children were developed in the simulation of the Particle and Heavy Ion Transport code System code. Contamination of the body surface with eight radionuclides found after the FDNPP accident was assumed to have been deposited on the neck and shoulder area. Results and Discussion: The detection limit was calculated as a function of ambient dose rate. In the case of 40 Bq/cm² contamination on the body surface of the neck, the present simulations showed that residual thyroid radioactivity corresponding to thyroid dose of 100 mSv can be detected within 21 days after intake at the ambient dose rate of 0.2 µSv/hr and within 11 days in the case of 2.0 µSv/hr. When a time constant of 10 seconds was used at the dose rate of 0.2 µSv/hr, the estimated survey meter output error was 5%. Evaluation of the effect of individual differences in the location of the thyroid gland confirmed that the measured value would decrease by approximately 6% for a height difference of ±1 cm and increase by approximately 65% for a depth of 1 cm. Conclusion: In the event of a nuclear disaster, simple measurements carried out using a NaI(Tl) scintillation survey meter remain effective for assessing ¹³¹I intake. However, it should be noted that the presence of short-half-life radioactive materials on the body surface affects the detection limit.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1227-1232
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• 2014

Background: Given that there are many Iranian women who have never had a Pap smear, this study was designed to develop and validate a measurement tool based on the Protection Motivation Theory to assess factors influencing the Iranian women's intention to perform first Pap testing. Materials and Methods: In this psychometric research, to determine the Content Validity Index (CVI) and the Content Validity Ratio (CVR), a panel of experts (n=10) reviewed scale items. Reliability was estimated through the Intraclass Correlation Coefficient (n=30) and internal consistency (n=240). Also, factor analysis (exploratory and conformity) was performed on the data of the sample women who had never had a Pap smear test (n=240). Results: A 26-item questionnaire was developed. The CVI and CVR scores of the scale were 0.89 and 0.90, respectively. Exploratory factor analysis loaded a 26-item with seven factors questionnaire (perceived vulnerability and severity, fear, response costs, response efficacy, self-efficacy, and protection motivation (or intention)) that jointly accounted for 72.76% of the observed variance. Confirmatory factor analysis indicated a good fit for the data. Internal consistency (range 0.70-0.93) and test-retest reliability (range 0.72-0.96) of sub-scales were acceptable. Conclusions: This study showed that the designed instrument was a valid and reliable tool for measuring the factors influencing the women's intention to perform their first Pap testing.