• 문화기술의 융합
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• 제2권4호
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• pp.77-82
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• 2016

가트너가 2013년부터 2015년까지 3년 연속 'IT 10대 전략기술'의 하나로 선정한 사물인터넷(IoT) 기술은 사람과 사물의 상호작용을 가능하게 하면서 고도화된 스마트사회를 구현할 수 있다. IoT 장비들이 인터넷으로 연결되어 있는 특성에 따라 해킹으로 인하여 무선신호 교란, 정보 유출, 데이터 위 변조와 서비스 거부 등 개인의 사생활 노출로부터 국가의 중요 기밀과 시설에 대한 위협까지의 중차대한 보안상 문제들이 나타날 수 있다. 본 논문에서는 IoT 장비들의 IP 노출에 대한 보안위협 사례들을 조사하고 문제점을 분석하여 개인의 사생활 노출이나 국가 기반시스템에 대한 피해 등 IP 노출로 인한 보안위협을 최소화하기 위한 방안을 제안한다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.523-530
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• 2005

본 연구에서는 IP형 운반용기의 개념설계를 위하여 소내 임시저장중인 방사성폐기물중 $200\;{\ell}$ 잡고체 드럼을 대상으로 운반용기에 적재 가능한 드럼의 최대표면선량률을 제시하고자 하였다. 이를 위해 잡고체 폐기물을 가연성과 비가연성으로 구분하였으며, 각각 혼합핵종이 균일 분포되어있는 경우와 단일핵종(Co-60)이 균일 분포되어있는 경우를 나누어 계산하였다. 연구결과, 가연성 잡고체 드럼에 혼합핵종이 분포되어 있는 경우, IP-1, IP-2-a, IP-2-b형 운반용기에 적재 가능한 최대표면선량률은 각각 3.60E-01, 8.85E-01, 1.27E+01 mSv/hr 이었으며, Co-60이 분포되어 있는 가연성 잡고체 드럼의 최대표면선량률은 각각 3.59E-01, 8.83E-01, 1.25E+01 mSv/hr 이었다. 비가연성 잡고체 드럼에 혼합핵종이 분포되어 있는 경우, IP-1, IP-2-a, IP-2-b형 운반용기에 적재 가능한 최대표면선량률은 각각 7.14E-01, 1.83E+00, 2.69E+01 mSv/hr이었으며, Co-60이 분포되어 있는 비가연성 잡고체 드럼의 최대표면선량률은 각각 7.13E-01, 1.81E-01, 2.62E+01 mSv/hr 으로 계산되었다. 이를 통해 운반가능 방사성내용물의 최대수량을 실측이 용이한 표면선량률 만으로 제시할 수 있었으며, 향후 다른 종류의 폐기물에 대해서도 차폐해석을 수행할 예정이다.

• 한국콘텐츠학회논문지
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• 제14권11호
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• pp.355-361
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• 2014

본 연구의 목적은 필름/증감지 방식에서 사용된 비감도 측정 방식을 이용하여 컴퓨터 방사선영상에서 영상판의 상대적 발광량을 평가하고자 하였다. 비감도 측정을 위한 특성곡선은 균일한 알루미늄으로 구성된 11 계단의 투과도계를 이용하였다. 디지털 방사선영상을 획득하기 위한 X선 조사조건은 50 kVp, 10 mAs로 조절했다. 영상후처리 알고리즘(MUSICA)의 모든 파라메터들은 제로화하여 원본 데이터에 근사화하였고 레이저 조사분류(exposure class)는 200으로 고정하였다. 영상판의 상대적 발광량 모델링은 X선 조사후 0, 4, 8, 12, 24 시간 보관한 영상판을 이용하였다. 그 결과, 컴퓨터 방사선영상시스템의 영상판 비감도 측정에 필요한 감도점 농도는 모든 특성곡선을 상대적으로 측정하기 용이한 2000 픽셀(pixel) 값이 적합하였다. 또한 영상판의 비감도가 저하될 때 영상신호를 생성하기 위한 빛 발광량도 감소하였다. 본 연구에서 제시한 비감도 평가방법은 컴퓨터 방사선영상시스템에서 영상판의 상대적 발광량을 평가할 수 있는 기술로 활용될 수 있을 것이다.

• 대한디지털의료영상학회논문지
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• 제10권2호
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• pp.23-31
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• 2008

Computed radiography(CR) has been widely used in the field of diagnostic radiography since digital X-ray image was introduced. The imaging performance of CR system was studied by analyzing the digital image data of the CR images which are the outcomes of the whole imaging system composed of image plate(IP), laser digitizer, analoge-digital convertor, and a given image processing unit. In this study, we used a conventional CR system made by Agfa. From the flat field image of 150$\times$150 image pixels, signal-to-noise ratio(SNR) was calculated. SNR of the CR image increases in proportion to logarithm value of the X-ray exposure irradiated on the IP. SNR is less than about 6 at the exposure below 0.2mR and is more than 10 at the exposure above 0.54mR. In our study, most of images obtained by the smaller exposures less than 2.0mR can not be readable. In general, the minimum value of the SNR ranges from 3 to 5. We obtained modulation transfer function(MTF) by analyzing the bar pattern image which was made under conditions as follows: X-ray tube potential was 55kVp, the IP exposure was 0.54 mR, and the distance between X-ray source to IP was 2m, where bar pattern was located on the IP. MTF is 23% at 2.5lp/mm spatial frequency. Provided that the MTF of noise equivalent modulation is 10%, the CR system has the limiting spatial resolution of 3.2lp/mm. If the image sharpness is evaluated by the spatial frequency where MTF is 50%. the corresponding spatial frequency is 0.5$\sim$0.75lp/mm. MTFA(Modulation Transfer Function Area) is 1.0lp/mm. Compared with the Fuji CR whose MTFA is 1.1lp/mm, Agfa CR in this study shows almost same MTFA performance.

• Archives of Pharmacal Research
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• 제14권2호
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• pp.188-192
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• 1991

Single non-lethal doses of chloroform $(CHCL_3)$ dichlorobromomethane $(CHCL_2Br)$, dibromochloromethane $(CHCIBr_2)$, or bromoform $(CHBr_3)$ were administered to male rats. Routes of exposure including single intraperitional (ip) and subcutaneous (sc) injection were used in order to permit comparison of severity of THM effects and renal toxicity was assessed at varied times following treatment. On an equimolar basis, sc administration of $CHBr_3$ (either 12 or 3 mmoles/kg) is more effective at increasing KW/BW than ip $CHCI_3$ treatment. Plasma urea nitrogen (BUN) following ip THM injections are markedly increased with all four THM at 24 hours post treatment. BUN response to $CHCL_2Br$ and $CHCIBr_3$-effected BUN levels have essentially returned to those of vehicle control. THM sc treatment results in a BUN response similar to that seen following ip treatment, with only the time course being different. With the exception of $CHCL_3$, sc and ip-treatments appear to be equally effective in evoking absolute BUN elevations. These results suggest that THM administration induce renal toxicity dependent upon the route or exposure.

• International Journal of Internet, Broadcasting and Communication
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• 제11권3호
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• pp.59-63
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• 2019

VoIP technology is a technology for exchanging voice or video data through IP network. Various protocols are used for this technique, in particular, RTP(Real-time Transport Protocol) protocol is used to exchange voice data. In recent years, with the development of communication technology, there has been an increasing tendency of services such as "Kakao Voice Talk" to exchange voice and video data through IP network. Most of these services provide a service with security guarantee by a user authentication process and an encryption process. However, RTP protocol does not require encryption when transmitting data. Therefore, there is an exposition risk in the voice data using RTP protocol. We will present the risk of the situation where packets are sniffed in VoIP(Voice over IP) communication using RTP protocol. To this end, we configured a VoIP telephone network, applied our own sniffing tool, and analyzed the sniffed packets to show the risk that users' data could be exposed unprotected.

• 한국컴퓨터정보학회논문지
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• 제13권1호
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• pp.143-151
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• 2008

본 논문에서는 자신의 Real IP주소의 노출을 피하기 위하여 우회적인 공격을 하는 침입자를 대상으로 하여 IP 역추적을 실시한다. Real IP역추적을 위하여 IF역추적 서버와 에이전트 모듈을 설계하고 실험실 인터넷 네트워크 시스템에 설치한다. 우회 접속자의 공격 탐지 및 추적 범위를 설정하고, 실제 공격을 하여. 일반적인 IP접속자료와 침입탐지 후에 치명적인 공격으로 차단된 Real IP자료를 생성하여 DB에 저장한다. 공격자의 Real IP는 Whois 서비스로 실체를 확인하고, 이를 법정의 증거자료로 삼기 위한 무결성과 신뢰성을 확보한 Forensic 자료를 생성한다. 본 논문 연구를 통하여 유비쿼터스 정보화사회의 역기능인 사이버 범죄의 예방효과와 효과적인 Real IP 역추적 시스템을 제시하고, 법의 처벌에 대한 Forensic자료 생성 기준을 확보한다.

• 치과방사선
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• 제29권2호
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• pp.397-405
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• 1999

Purpose: To clarify the usefulness and the limitation of Digora system/sup (R)/ by evaluating the physical characteristics as the quantitative image on Image Plate(Ip). Materials and Methods: Radiograms were taken by Heliodent MD(Siemens Co.. Germany) with the image plate for adult. Cu-step wedge as reference material. and three pieces of dry mandibular bone. Image analysis was performed by single color enhancement. density measurement with histogram. The relationship between the exposure conditions and the distribution of the pixel values of the image. the variation of pixel values of each step of Cu-step wedge at two different area and Cu-equivalent value of three pieces of dry mandibular bone measure by the conversion equation. Results: There was no linear relationship between the exposure condition and the average pixel value of the image. of which the distribution was not even. The pixel value differences between the center portion and the periphery were ranged from 60 to 70 in vertical plane and from 15 to 26 in horizontal plane. Two plot profile formed at two different areas of the Cu-step wedge were different. The measured Cu-equivalent values showed the discrepancy among the times of measurement. Conclusion: As above results. Image Plate(Ip) of Digora system/sup (R)/ showed the limitation as the quantitative image. The physical property of IP was expected to need to be compensated for the quantitative evaluation of the bone or others

• 대한디지털의료영상학회논문지
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• 제2권1호
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• pp.92-95
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• 1996

Computed Radiography(CR) is a relatively new technology that relies on an image plate(IP) as an alternate x-ray sensor to screen/film. Standard CR cassettes do not have lead foil behind the IP to control scatter radiation. The result of this study indicate that such control is needed. In most screen/film cassettes, that lines the rear of the cassette eliminates back scatter radiation. This study was performed to Investigate on the effects of back scatter in CR images by size of exposure field, distance between the CR cassette and the wall of radiography room. 1. It showed artifacts from hinges and clips located on the back of CR cassette by back scatter radiation. 2. The greater effects of back scatter radiation in CR images was attributed to the greater size of exposure field and the longer distance between the CR cassette and the wall of radiography room.

• Environmental Analysis Health and Toxicology
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• 제29권
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• pp.1.1-1.7
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• 2014

Objectives The present subacute study was designed to evaluate the effect of coenzyme Q 10 (CoQ10) in the 28 days aroclor 1254 exposure induced oxidative stress in mice brain. Methods Biochemical estimations of brain lipid peroxidation (LPO), reduced glutathione (GSH), and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and acetyl cholinesterase (AChE), and histopathological investigations of brain tissue were carried out. Results Oral exposure of aroclor 1254 (5 mg/kg) led to significant decrease in levels of GSH, and activities of SOD, CAT, GPx, and AChE, and increase in LPO. These aberrations were restored by CoQ10 (10 mg/kg, intraperitoneal injection [IP]). This protection offered was comparable to that of L-deprenyl (1 mg/kg, IP) which served as a reference standard. Conclusions Aroclor 1254 exposure hampers the activities of various antioxidant enzymes and induces oxidative stress in the brains of Swiss albino mice. Supplementation of CoQ10 abrogates these deleterious effects of aroclor 1254. CoQ10 also apparently enhanced acetyl cholinesterase activity which reflects its influence on the cholinergic system.