• 사회복지연구
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• 제41권3호
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• pp.327-348
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• 2010

본 연구는 청소년에 대한 빈곤의 영향을 주로 가족의 측면에서 연구하였던 기존의 관점에서 탈피하여, 빈곤청소년이 거주하는 지역사회 환경의 위험성과 폭력성에 주목하였다. 즉, 본 연구는 빈곤으로 인해 더 위험한 환경에서 거주하게 되는 청소년이 일반 청소년보다 폭력에 더 많이 노출되는지를 살펴보고, 이것이 그들의 우울과 불안을 높이는지 분석하였다. 분석 자료로 '한국청소년패널데이터' 중2 패널자료 중에서 3-5차년도 종단데이터가 활용되었으며, 통계방법으로는 구조방정식모형이 이용되었다. 분석 결과, 청소년의 빈곤 자체가 폭력피해 경험을 직접적으로 증가시키지는 않았으나 빈곤으로 인해 위험한 지역사회 환경에 거주하게 됨으로써 더욱 많은 폭력피해와 두려움을 경험하게 되며 이는 우울 및 불안으로 이어지는 것으로 나타났다. 이 결과를 바탕으로 청소년에 대한 빈곤의 부정적 영향을 줄이는 데에 지역사회의 역량 강화의 중요성을 함의로 지적하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.270-270
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• 2012

Low temperature atmospheric pressure plasmas (APPs) have been known to be effective for living cell inactivation in the water [1]. Many earlier research found that pH level of the solution was changed from neutral to acidic after plasma treatment. The importance of the effect of acidity of the solution for cell treatments has already been reported by many experiments. In addition, several studies have demonstrated that the addition of a small amount of oxygen to pure helium results in higher sterilization efficiency of APPs [2]. However, it is not clear yet which species are key factors for the cell treatment. To find key factors, we used GMoo simulation. We elucidate the processes through which pH level in the solution is changed from neutral to acidic after plasma exposure and key components with pH and air variation with using GMoo simulation. First, pH level in a liquid solution is changed by He+ and He(21S) radicals. Second, O3 density decreases as pH level in the solution decreases and air concentration decreases. It can be a method of removing O3 that cause chest pain and damage lung tissue when the density is very high. H2O2, HO2 and NO radicals are found to be key factors for cell inactivation in the solution with pH and air variation.

• 한국CDE학회논문집
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• 제15권4호
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• pp.297-305
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• 2010

Medical image acquisition techniques such as CT and MRI have disadvantages in that the numerous time and efforts are needed. Furthermore, a great amount of radiation exposure is an inherent proberty of the CT imaging technique, a number of side-effects are expected from such method. To improve such conventional methods, a number of novel methods that can obtain 3D medical images from a few X-ray images, such as algebraic reconstruction technique (ART), have been developed. Such methods deform a generic model of the internal body part and fit them into the X-ray images to obtain the 3D model; the initial shape, therefore, affects the entire fitting process in a great deal. From this fact, we propose a novel method that can generate a 3D vertebraic generic model based on the statistical database of CT scans in this study. Moreover, we also discuss a method to generate patient-tailored generic model using the facts obtained from the statistical analysis. To do so, the mesh topologies of CT-scanned 3D vertebra models are modified to be identical to each other, and the database is constructed based on them. Furthermore, from the results of a statistical analysis on the database, the tendency of shape distribution is characterized, and the modeling parameters are extracted. By using these modeling parameters for generating the patient-tailored generic model, the computational speed and accuracy of ART can greatly be improved. Furthermore, although this study only includes an application to the C1 (Atlas) vertebra, the entire framework of our method can be applied to other body parts generally. Therefore, it is expected that the proposed method can benefit the various medical imaging applications.

• Journal of Astronomy and Space Sciences
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• 제31권1호
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• pp.25-31
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• 2014

There has been a rapid increase of the concern on the space radiation effect on pilots, crew and passengers at the commercial aircraft altitude (~ 10 km) recently. It is because domestic airline companies, Korean Air and Asiana Airlines have just begun operating the polar routes over the North Pole since 2006 and 2009 respectively. CARI-6 and CARI-6M are commonly used space radiation estimation programs which are provided officially by the U.S. federal aviation administration (FAA). In this paper, the route doses and the annual radiation doses for Korean pilots and cabin crew were estimated by using CARI-6M based on 2012 flight records. Also the modeling concept was developed for our own space radiation estimation program which is composed of GEANT4 and NRLMSIS00 models. The GEANT4 model is used to trace the incident particle transports in the atmosphere and the NRLMSIS00 model is used to get the background atmospheric densities of various neutral atoms at the aircraft altitude. Also presented are the results of simple integration tests of those models and the plan to include the space weather variations through the solar proton event (SPE) prediction model such as UMASEP and the galactic cosmic ray (GCR) prediction model such as Badhwar-O'Neill 2010.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The Korea-Japan Plastics Processing Joint Seminar
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• pp.7-13
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• 2003

Microlens arrays were fabricated using a novel fabrication technology based on the exposure of a PMMA (Polymethylmethacrylate) sheet to deep X-rays and subsequent thermal treatment. X-ray irradiation causes the decrease of molecular weight of PMMA, which in turn decreases the glass transition temperature and consequently causes a net volume increase during the thermal cycle resulting in a swollen microlens. A new physical modeling and analyses for micro lens formation were presented according to experimental procedure. A simple analysis based on the new model is found to be capable of predicting the shapes of micro lens which depend on the thermal treatment. For the replication of micro lens arrays having various diameters with different foci on the same surface, the hot embossing and the microinjection molding processes has been successfully utilized with a mold insert that is fabricated by Ni-electroplating based on a PMMA microstructure of micro lenses. Fabricated microlenses showed good surface roughness with the order of 1nm.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1111-1117
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• 2014

Golestan province has a reputation for relatively high incidence rates of gastric cancer in Iran. Along with dietary, lifestyle and environmental influential factors, soil selenium and high levels of pesticide used may exert influence in this region. The present study was designed for modeling the influential predictors on incidence of gastric cancer in Golestan. All registered cases of gastric cancer from March 2009 to March 2010 (49 females and 107 males) were investigated. Data were gathered by both check list and researcher made questionnaire (demographic, clinical and lifestyle characteristics) and analysed using logistic regression. Mean (${\pm}SD$) age at diagnosis was $62.9{\pm}13.8$ years. CIR and ASR of gastric cancer showed 9.16 and 13.9 per 100,000 people, respectively. Based on univariate logistic regression, a history of smoking (OR= 2.076), unwashed hands after defecation (OR= 2.612), history of cancer in relatives (OR= 2.473), history of gastric cancer in first-degree relatives (OR= 2.278), numbers of gastric cancers in first-degree relatives (OR= 2.078), history of X-ray and dye exposure (OR= 2.395), history of CT scan encounter (OR= 2.915), improper food habits (OR= 3.320), specific eating behavior (OR= 0.740), consumption of probable high risk foods (OR= 2.942), charred flesh (OR= 1.945), and animal fat (OR= 2.716) were confirmed as a risk factors. Changes in lifestyle may be expected to increase gastric cancer incidence dramatically in the near future. Therefore, appropriate educational interventions should be designed and implemented by competent authorities.

• Journal of Radiation Protection and Research
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• 제42권2호
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• pp.91-97
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• 2017

Background: A gamma energy identifying algorithm using spectral decomposition combined with smoothing method was suggested to confirm the existence of the artificial radio isotopes. The algorithm is composed by original pattern recognition method and smoothing method to enhance the performance to identify gamma energy of radiation sensors that have low energy resolution. Materials and Methods: The gamma energy identifying algorithm for the compact radiation sensor is a three-step of refinement process. Firstly, the magnitude set is calculated by the original spectral decomposition. Secondly, the magnitude of modeling error in the magnitude set is reduced by the smoothing method. Thirdly, the expected gamma energy is finally decided based on the enhanced magnitude set as a result of the spectral decomposition with the smoothing method. The algorithm was optimized for the designed radiation sensor composed of a CsI (Tl) scintillator and a silicon pin diode. Results and Discussion: The two performance parameters used to estimate the algorithm are the accuracy of expected gamma energy and the number of repeated calculations. The original gamma energy was accurately identified with the single energy of gamma radiation by adapting this modeling error reduction method. Also the average error decreased by half with the multi energies of gamma radiation in comparison to the original spectral decomposition. In addition, the number of repeated calculations also decreased by half even in low fluence conditions under $10^4$ ($/0.09cm^2$ of the scintillator surface). Conclusion: Through the development of this algorithm, we have confirmed the possibility of developing a product that can identify artificial radionuclides nearby using inexpensive radiation sensors that are easy to use by the public. Therefore, it can contribute to reduce the anxiety of the public exposure by determining the presence of artificial radionuclides in the vicinity.

• 에너지공학
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• 제29권2호
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• pp.23-29
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• 2020

본 연구에서는 최근 10년간의 미세먼지 관련 뉴스 데이터를 수집하여 LDA 분석을 통해 최적 토픽을 도출하였다. 최적 토픽으로 선별된 80개의 이슈를 미세먼지 정책의 시각에서 해석하였다. 연구결과, 기온과 같은 날씨와 관련된 정보와 미세먼지 농도가 관련되어서 이슈화되는 경향이 있었다. 다음으로 미세먼지 저감 대책의 일환으로 노후경유차 운행 제한 제도와 저감 장치 부착과 같은 이슈의 빈도수가 높았다. 국민에 대한 제도 변경 안내를 포함하여 시민과 운수업자와의 갈등도 주요한 토픽으로 나타났다. 미세먼지 문제의 해결을 위한 수소차 보급과 같은 대안도 주요 토픽으로 분석되었다. 또한 미세먼지 관련 공기청정기 등 제품 관련 주제, 취약계층을 미세먼지로부터 보호하는 정책과 관련된 주제, 연구개발을 통한 미세먼지 저감 관련 주제가 주요 화두로 제기되었다. 미세먼지 대책은 사회 이슈로 정부 정책과 밀접한 관련이 있다고 볼 수 있다. 또한 본 연구를 통해 토픽 상에서는 거시적인 정부정책 자체보다는 시민의 안전, 시혜적인 정책이나 이해관계자간의 갈등이 정부정책 변화와 연동하여 중요한 의미를 지니는 것으로 나타났다.

• 한국수학교육학회지시리즈A:수학교육
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• 제58권3호
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• pp.367-381
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• 2019

본 연구는 국외 수학 교사교육 사례 보고의 일환으로, 미국의 예비교사들이 넓이 $0.14m^2$를 모델링하고 설명하는 과정을 분석하고 논의하였다. 수학방법론을 수강한 총 94명의 예비교사들이 자신이 이해하는 바를 문장으로 서술하기, 교구나 그림 등을 통해 모델을 제시하기, 학생들의 수준을 고려하여 구두로 설명하기 등으로 이루어진 일련의 활동에 참여하였으며, 이 자료들이 분석에 이용되었다. 분석 결과, 개념들 간의 연계성, 양적 및 질적 추론, 적절한 용어의 사용, 개념적 이해 등에 있어 성공 및 오류 사례 간에 큰 차이가 있었다. 본 연구는 수학교사교육자들이 예비교사들에게 수학지식과 교수방법이 유기적으로 통합된 과제를 교사교육 초기부터, 그리고 지속적으로 제공할 것을 제안한다.

• 한국콘텐츠학회논문지
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• 제21권4호
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• pp.1-13
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• 2021

코로나19에 대한 전세계적 팬데믹이 진행되고 있는 상황에서 잘못된 정보가 대중에게 노출되었을 경우 발생할 수 있는 잠재적인 문제에 대한 우려와 함께 현재 주요 앱 마켓에서 민간 애플리케이션에 대한 차단 조치도 단행되고 있다. 그러나 감염병 상황에서 중앙집중식의 일방적인 정보 전달보다 대중이 스스로 정보를 공유하는 것이 효과적인 측면도 동시에 존재한다. 본 연구는 텍스트마이닝을 이용해 감염병 상황에서 민간 주도의 정보제공에 대한 이용자 반응을 분석한다. 이를 위해 정부와 민간이 현재 한국의 구글 플레이스토어에서 제공하고 있는 모든 코로나19 애플리케이션에 대한 이용자들의 반응에 대한 토픽 모델링과 감성분석을 실시한다. 분석 결과, 이용자들은 정보의 신뢰성, 위험회피, 실시간성, 유용성, 안정성 등 모든 차원에서 정부 대비 민간 애플리케이션에 대해 더 긍정적인 반응을 보이는 것으로 분석되었다. 분석 결과를 바탕으로 민간 애플리케이션에 대한 일방적인 차단이 아닌, 사후적인 모니터링 시스템을 도입하는 방안 등을 제안한다.