• 한국전자파학회논문지
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• 제24권10호
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• pp.1017-1026
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• 2013

Mobi-Kids 연구의 노출량 평가 분야에는 4개국이 참여하고 있다. 각 국은 해당 지역 또는 자국의 통신 환경 및 통신 방식 등을 고려하여 평가를 수행하고, 그 결과는 휴대전화로부터 복사되는 무선주파수 및 극저주파수의 어린이 및 청소년 노출에 대한 중추신경계 발암 영향을 평가하기 위해 환자-대조군 대상자의 누적 노출량 평가에 활용된다. 본 논문에서는 Mobi-Kids 연구의 노출량 평가 프로토콜에 따라 과거 약 10년간 우리나라에서 사용해온 휴대전화의 노출 유형을 분석한다. 국내 출시 휴대전화 모델 조사, 그 결과를 바탕으로 한 노출 유형 분류, 수치해석적 대표 휴대전화 설계 방법, 그리고 휴대전화의 ELF 복사 측정 등을 주요 내용으로 한다.

• The Korean Journal of Physiology and Pharmacology
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• 제21권2호
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• pp.179-188
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• 2017

With the explosive increase in exposure to radiofrequency electromagnetic fields (RF-EMF) emitted by mobile phones, public concerns have grown over the last few decades with regard to the potential effects of EMF exposure on the nervous system in the brain. Many researchers have suggested that RF-EMFs can effect diverse neuronal alterations in the brain, thereby affecting neuronal functions as well as behavior. Previously, we showed that long-term exposure to 835 MHz RF-EMF induces autophagy in the mice brain. In this study, we explore whether shortterm exposure to RF-EMF leads to the autophagy pathway in the cerebral cortex and brainstem at 835 MHz with a specific absorption rate (SAR) of 4.0 W/kg for 4 weeks. Increased levels of autophagy genes and proteins such as LC3B-II and Beclin1 were demonstrated and the accumulation of autophagosomes and autolysosomes was observed in cortical neurons whereas apoptosis pathways were up-regulated in the brainstem but not in the cortex following 4 weeks of RF exposure. Taken together, the present study indicates that monthly exposure to RF-EMF induces autophagy in the cerebral cortex and suggests that autophagic degradation in cortical neurons against a stress of 835 MHz RF during 4 weeks could correspond to adaptation to the RF stress environment. However, activation of apoptosis rather than autophagy in the brainstem is suggesting the differential responses to the RF-EMF stresses in the brain system.

• Journal of Magnetics
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• 제21권3호
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• pp.460-467
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• 2016

Magnetic hyperthermia mediated by superparamagnetic particles is mainly based in sinusoidal waveforms as excitation signals. Temperature changes are conventionally explained by rotation of the particles in the surrounding medium. This is a hypothesis quite questionable since habitual experimental setups only produce changes in the magnetic module, not in the field lines trajectories. Theoretical results were tested by changing the waveform of the exciting signal in order to compare non-sinusoidal signals against sinusoidal signals. Experiments were done at different frequencies: 200 KHz, 400 KHz, 600 KHz, 800 KHz and 1 MHz. Superparamagnetic Iron Oxide samples (SPION), made of magnetite ($Fe_3O_4$) and suspended in water (100 mg/ml), were used. Magnetic field strength varies from $0.1{\pm}0.015KA/m$ to $0.6{\pm}0.015KA/m$. In this study was observed that the power loss depends on the applied frequency: for 1 to 2.5 RMS current the responses for each signal are part of the higher section of the exponential function, and for 3.5 to 8 RMS current the response is clearly the decrement exponential function's tale (under $1{\times}10^3LER/gr$).

• 환경생물
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• 제22권4호
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• pp.507-512
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• 2004

This study was focused on the risk assessment of whether radiofrequency electromagnetic fields generated by mobile phone is cytogenetically toxic or not. We conducted the effects of 835-MHz electromagnetic field (EMF) on DNA strand breaks in mouse thymic lymphoma L5178Y $Tk^{+/1-}$ cells using alkaline comet assay. EMF frequency 835-MHz we chosen is one of the most popular communication frequency bands in Korean code-division multiple-access (CDMA) mobile phone system. The cells were exposed to 835-MHz EMF alone or 835-MHz EMF combined with cyclophosamide(CPA) or 4-nitroquinoline-1-oxide (4NQO) at specific absorption rate (SAR) of 4.0 W $kg^{-l}$ for 24 and 48hrs. DNA damage expressed as tail moment was increased more than two-fold after exposure to 835-MHz EMF for 24 and 48hr. In particular, CPA for 48hr and 4NQO for 24 hr enhanced notably the tail moment to 9-fold and 16-fold in the presence of 835-MHz EMF, respectively, compared to each single treatment. From these results, it appears that exposure to CDMA-mobile phone radiation at 835-MHz frequency may potentiate DNA strand breaks of mouse thymic lymphoma L5178Y $Tk^{+/1-}$;cells under the defined conditions of this study.

• 정보처리학회논문지B
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• 제13B권4호
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• pp.369-376
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• 2006

디지탈 변환과 기기간의 전송 영향으로 화질이 떨어진 디지탈 영상의 복구는 잡음 발생 및 그 역 과정의 모형화를 통해 이루어낼 수 있다. 스캐너로 읽혀진 서류 영상이나 위성 사진에서 잡음 및 반점을 제거하는 과정이 좋은 예이다. 그러나 잡음 발생의 비선형성은 그 역 과정의 이론적 이해를 어렵게한다. 본 논문에서는 충격 잡음에의해 화질이 떨어진 이진 서류 영상의 복구 방법들을 심층 분석하는 것에 촛점을 맞추었다. 본 연구 결과에 의하면 이진 서류 영상의 잡음 제거 방식으로 '가중 중앙값' 여과기와 '리' 여과기가 다른 여과기에 비해 효과적임을 보여준다. 반면 '웨이브렛' 여과 방식은 타 방식보다 100여배의 시간이 소요되어 비효율적이다. 본 논문에서는 가중 중앙값 여과기에 쓰이는 가중치에 대한 연구 결과를 제시하였다.

• Ocean and Polar Research
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• 제33권1호
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• pp.1-11
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• 2011

This study describes measurements of fast ice recorded on May 23, 2009, in Kongsfjorden (translated as 'Kongs Fjord'), an inlet on the west coast of Spitsbergen in the Svalbard Archipelago. Seasonal fast ice is an important feature for Svalbard fjords, both in relation to their physical environment and also the local ecosystem, since it grows seaward from the coast and remains in place throughout the winter. Ice thickness, snow, ice properties, and wind speed were measured, while SAR (Synthetic Aperture Radar) data was observed simultaneously observed two times from ALOS-PALSAR (L-band). Measured ice thickness was about 25-35 cm while the thickness of ice floe broken from fast ice was measured as 10-15 cm. Average salinity was 1.9-2.0 ppt during the melting period. Polarimetric data was used to extract H/A/alpha-angle parameters of fast ice, ice floe, snow and glacier, which was classified into 18 classes based on these parameters. It was established that the area of fast ice represents surface scattering which indicates low and medium entropy surface scatters such as Bragg and random surfaces, while fast ice covered with snow belongs to a zone of low entropy surface scattering similar to snow-covered land surfaces. The results of this study will contribute to various interpretations of interrelationships between H/A/alpha parameters and the wave scattering Phenomenon of sea ice.

• 복식
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• 제26권
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• pp.69-85
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• 1995

Recently Southeast Asia has developed, so the world concerns about these regions. Ethnic fashion in 90's is mostly the influence of these regions' folk costume. The purpose of this study is to review aes-thetic aspects of folk costume in Southeast Asia, to investigate the influence on modern fashion and to predict the possibility of Asia fashion's adaption to modern fashion and to help the cre-ation of fashion design. First of all, the folk costume in Southeast Asia is classified drapery style and sarong style. These non-west clothing appeal to modern fashion as the oriental tranditional beauty. Ethnic fashion appeared in 1990's is attempted to be more complex and variable than the pre-vious ethnic fashion. Asian ethnic fashion influenced from folk costume of Southeast Asia is-wholly or party-the style, color, motif from each country's folk costume. And each country's unique art became the motive of the creative design. Specially, Aosai and Quan in Vietnam and sar-ong style in most Southeast Asia are important motives expressing minority's nostalgia. These are expressed in variable ways. Which are harmonized with latest other fashion trend : retro style and naturalism, Layered look, hippie look, unfinished sewing technic and manual technic are used one image matched the folk costume of Southeast Asia which is natural. Another characterstic in Asian ethnic fashion is a multi-ethnic. This harmonizes the different culture between the Orient and the West beyond the age and culture, and combines each folk costume. It is involved that the fashion can develop indivisual country's costumes mixed with her own unique characteristics and the fashion break the traditional concept and disagree with a certain coordinate rule and it indicates that the fashion shows various style, mood, volume and room as well as space. Like this recent Asian ethnic fashion comes to us in a strange favor. The people who are tired of traditional western civilization's outcome will receive a great tastes from the Asian ethnic fashion.

• 한국항해항만학회지
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• 제30권3호
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• pp.181-187
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• 2006

선형파 이론에 의한 파랑스펙트럼 분포에 의해서는 30m 크기의 파랑은 현실적으로 거의 발생 불가능하다고 인식되어 왔다. 그러나 최근의 위성 영상을 이용한 조사에 의해 3주간의 기간 동안 25m 이상의 거대파가 10개 이상 관측됨에 따라 실해역에서 빈번히 마주칠 수 있는 현상임이 입증되었으며 이에 따라 지금까지 원인 불명으로 치부되어 왔던 많은 해양 재난이 거대파에 의해 발생했던 것으로 추정되고 있다. 거대파의 발생 원인으로는 파군 형성과 관련한 파고분포 특성의 변화, 전파하는 파군의 비선형 공명간섭 등이 제기되고 있으나, 그 출현의 복잡성과 자료의 부족 등으로 아직 명확하게 해명되지 못하고 있다. 본 연구에서는 실해역에서 발생하는 거대파의 실태 및 선형 및 비선형 파랑집중 이론에 근거한 거대파 발생 기구를 고찰하였으며, 비선형 파랑전파를 모사할 수 있는 수치모형을 개발하여 비선형 파랑 집중에 의한 거대 파랑의 형성을 모사하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5701-5707
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• 2014

Background: Salivary gland tumours, which account for approximately 3% of head-neck cancers, are a heterogeneous group and thus it is difficult to identify their epidemiological characteristics. The aim of this study is to determine demographic features and histopathologic distribution of parotid neoplasms in a large sample from Turkey. Materials and Methods: This study was conducted retrospectively on 136 parotidectomy materials from operations between May 2009-May 2013. Age, gender, tumor diameter, histopathological diagnosis and surgical margin status were recorded. Results: The benign cases were 112 (82.4%), while the malignancies were 24 (17.6%). The accuracy rate of FNAC was 91%. There were 46 (33.8%) male and 90 (66.2%) female patients. Female/male ratio (M/F=0.5) was two, the Warthin (WT) tumor being more apparent in males (p<0.05). Pleomorphic adenoma (PA) was detected most frequently among benign pathologies at 61.6% (69/112), while the Warthin Tumor (WT) was detected as the second most frequent tumor at 20.5% (23/112). Mucoepidermoid carcinoma (MEC) and carcinoma ex pleomorphic adenoma (Ca ex PA) were detected at equal frequency at 20.8% (5/24) among malign tumors. These were followed by acinic cell carcinoma at 16.7% (4/24). While the surgical margin was positive in ten patients with malignant tumors (41.7%), all of the benign tumors were negative (p<0.01). No significant difference was detected in the age-gender of patients, tumor size and distribution of sites among benign and malignant groups (p>0.05). Conclusions: Pleomorphic adenoma is the most frequently reported benign tumor almost in all global literature. Yet, the distribution of malignant tumors displays geographical differences. Based on these data, we believe that our findings will provide a significant contribution to future epidemiological studies. We think that it will be beneficial to generate awareness on parotid tumors and ensure a fight against smoking as with all head-neck cancers.

• 한국지리정보학회지
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• 제1권1호
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• pp.109-117
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• 1998

하나의 원격탐사자료를 이용하여 얻고자하는 정보를 추출하는 것은 한계가 있다. 현재 원격탐사분야의 세계적인 추세는 광학위성자료와 레이다 위성자료, 항공사진, 항공 스캐닝 데이터, 지상의 분광스캐너 데이터 등을 모두 통합하여, 정보를 추출하고 있다. 그러나 국내에서는 이들 자료의 연구가 따로 행하여지고 있다. 본 연구에서는 광학위성자료와 레이다 위성 자료의 통합기법을 소개하고 이렇게 통합하여 얻어진 자료를 기존연구방식을 이용하여 추출된 결과와 비교하여 고찰해 보고자 하였다. 이를 위하여 서로 다른 여러 가지 디지털 영상의 혼합결과물을 이용하여 분류를 수행하는데 있어서 독자적인 RGB 가법혼합의 밴드별 상관관계의 방식보다는 각기 다른 해상력의 영상들을 IHS 변환 후 다시 RGB 변환하여 얻어진 결과물의 시각적 특성치를 조사하고, 영상을 혼합하는 것이 정확도 및 해상도의 향상을 기대할 수 있다는 비교결과를 얻을 수 있었다.