http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정하규 ( Hague Chung ),이희준 ( Lee Heejun ),강정호 ( Jungho Kang ),전문석 ( Moon-soeg Jun ) 한국정보처리학회 2016 한국정보처리학회 학술대회논문집 Vol.23 No.1
정보통신의 발달로 인하여 사물간의 필요한 모든 정보를 상호작용하는 IoT(Internet of Thing)환경이 발전하고 있다. 홈 IoT환경에서는 스마트폰 어플리케이션을 통하여 집안 내부를 살펴보고 외부 침입자가 들어오면 이를 감지, 신고할 수 있는 IP Camera의 수요가 증가되고 있다. 그러나 IP Camera의 해킹 사례가 증가 하고 있고 취약한 인증, 잠재적인 공격 가능성 등 보안문제가 발견되었다. 이에 본 논문에서는 대중적으로 많이 사용되고 있는 IP Camera와 Smart Phone과의 안전한 사용자 인증 프로토콜을 제안하였다.
Effects of Various Laser Wavelengths and Power Densities on the Ocular Damage in Pigmented Rats
Phil-Sang Chung,Jang-In Shin,Moo-hwan Chang,So-Young Chang,Jung-Wook Kang,Heejun Hwang,Jin-Chul Ahn 대한의생명과학회 2008 Biomedical Science Letters Vol.14 No.3
With the widespread use of laser in medical and industrial settings, the incidence of laser injury to the ocular continues to grow among workers involved in handling lasers. The aim of this study is to compare ocular damages after irradiation with various laser wavelengths and power density. Ocular of pigmented rats was irradiated with CO₂ laser, 1064 ㎚ Nd:YAG laser, and 532 ㎚ diode laser. We observed damage of cornea, lens, and retina using slit lamp microscope and funduscopy. H&E staining of histopathology were applied to study the specimens. The higher exposure (200 ㎽/㎠, 10 sec) with CO₂ laser resulted in severe damage at the cornea. For the 1064 ㎚ Nd:YAG laser, the higher exposure than 10 ㎽/㎠ (10 sec) resulted in damage at the cornea and lens. Further, with the 532 ㎚ diode laser, retinal lesions were induced when 10 ㎽/㎠ (0.25 sec) was delivered to the eye. Theses results suggest that the ocular damages are different from various laser wavelength and power density.
Hyun Young Kim,Heejun Chung 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2
Since the National Research and Development Innovation Act. was enacted, evaluation and management of research outputs become more important. The research output is defined as all types of information resources produced from the scientific research activities in each research phase, such as learning, proposing, performing, and publishing. Among them, research outputs mainly from the publishing phase have been systematically managed, including articles, books, technical reports, patents, and software. KINAC, like other Korean R&D institutions, has also achieved growth in research outputs, through continuously increased investment in R&D projects. However, R&D productivity, technology transfer, and commercialization remain low level. The importance of R&D performance diffusion has been emphasized. It’s because the creation of economic value through the utilization of research results has been emerging as a key issue in R&D policy. Therefore, various policies are being nationally pursued to promote the utilization of research achievements, but the results are not being effectively utilized and disseminated. In the field of nuclear nonproliferation and security, it is also difficult to diffuse the R&D performance. In this study, the research outputs of KINAC from 2010 to 2021 were analyzed. A number of research outputs have been made and managed, but the R&D performances have not been analyzed and identified yet. In addition, supportive methods were suggested for efficient performance management toward diffusion. For this purpose, some policies of Korea and other countries concerning performance diffusion -related policies were reviewed. The best practices of performance management and applications were also reviewed and compared to the KINAC cases. As a result, the number of research output has dramatically increased during the last 10 years, showing an average annual total output of 84 and year-on-year increase of 18%. The biggest change was in the conference papers and journals, whereas, there were no trends by year in the case of the technical reports and patents. Of course, it was proportional to the size of the organization, the number of research projects, and its budget. Because many studies highlight the importance of institutional resources, capabilities, and processes for performance management as factors affecting efficient diffusion, the current status of our process was also identified. This study is expected to be applied to the improvement of the performance management of the institute, leading to the enhancement of the R&D performance application.
반응조 형상이 상향류 혐기성 슬러지 소화에 미치는 영향
김대영,김희준,박기영,최영균,정태학 대한상하수도학회 2003 상하수도학회지 Vol.17 No.4
Digestion of primary sludge was conducted to evaluate the effects of reactor configuration using UAD, CUAD, TPAD, and semi-continuos CSTR. Highest VSS reduction and gas production were obtained in CUAD at all HRT. More efficient digestion was accomplished in upflow digesters compared to TPAD and CSTR. Higher thickening of solids in reactor and longer solids retention were main reasons for the enhanced digestion in CUAD and UAD. Performance based on the SRT of CUAD was nearly identical to that of UAD. However, those of TPAD and CSTR were lower than that of CUAD. Particulate and soluble organics in upflow reactors were well adsorbed due to secreted extracellular polymeric substances from the sludge granules. These might result in close proximity of microorganisms and substrates and enhanced hydrolysis. Additionally, diverse anaerobic microorganisms and neutral pH in upflow reactor could induce more activity of hydrolytic enzymes and sludge granules might offer lower thermodynamic energy state. While, excessive mixing in CSTR could break conglomerates of enzymes and substrates into fine particles, which resulted in lowered hydrolysis. Low pH level in acid fermenter of TPAD lowered hydrolysis of the particulate substrates.
A Study on the Effect of Frequency Scaling Factor on FBP
Jisu Kim,Jihun Moon,Heejun Chung,Kyung Taek Lim,Sung Woo Kwak 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2
For safeguarding dry storage facilities, a tomography system based on fast and thermal neutron detection was studied in Korea Institute of Nuclear Nonproliferation and Control. The study was conducted laboratory-scale experiments based on a custom built 1/10th scale model cask, He-4 gas scintillation detector array, and multiple 252Cf sources. A filtered back projection (FBP) was utilized to obtain the cask image via MATLAB. The Ram-Lak filter (ramp filter) was employed in FBP for improved the reconstructed image quality. The Ram-Lak filter is the increasing amplitude filter due to the increasing spatial frequency of the image. In spatial frequency, the frequency of brightness change in the low-frequency region is relatively low, and the frequency of brightness change in the highfrequency region is large. Thus, the high-frequency region in the neutron tomographic image is near the neutron sources and the cask, and the low-frequency region is outside of the cask and/or between the source and cask in the study. In order to apply the ramp filter, a Fourier transform is initially performed on projection data, and image reconstruction is performed with the corrected projection data. In this case, the filter is linearly changed. Therefore, a small filter value is applied at lower spatial frequencies to reduce the projection data, and a large filter value is applied at high spatial frequencies to reduce the projection data. The filter scale is a fraction of frequency amplitude, and the filter value applied to the projection data is determined according to the filter scale. This study was conducted for discussion of the image quality due to the effect of the filter scale used for image reconstruction of a neutron tomography system. The results show that in the experiment with one source, the source location was founded when we used the frequency scale of 0.5 and over. In the double or triple source experiment, the source locations and relative activities were found when we used a filter scale of 0.4 to 0.6. When the filter frequency scale of 0.7 to over, the relative activities are hard to know. It can be found that if the filter value is too large or too small, distortion may occur in the reconstruction results. Therefore, it seems reasonable to set a value between 0.4 and 0.6 as the scaling factor for the neutron tomography system. In the future, additional comparative studies will perform validation of the frequency scaling methods.