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Performance Enhancement of Solar-Driven Steam Generator by Local Wettability Control (태양열 활용 증발기의 성능 향상을 위한 국소적 젖음성 제어에 관한 실험적 연구)

  • Choi, Jinwook;Seo, Yongwon;Mo, Hyeong-Uk;Kim, Seolha
    • Korean Chemical Engineering Research
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    • v.60 no.2
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    • pp.255-259
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    • 2022
  • Solar membrane steam generation is a very promising technology that can harvest purified water from seawater or wastewater during the current danger of running out of pure water. However, solar Membrane steam generation had direct contact with water, making it difficult to increase the efficient amount of evaporation. Here, we propose solar membrane steam generator composed of polydimethylsiloxane (PDMS) and graphene oxide (GO) and improved evaporation through wettability control in part throughout the water-absorbing membrane. Wettability control has shown significant improvements in thermal localization and temperature rise in the area of heat exchange with sunlight. The evaporator has an evaporation rate of 1.54 kg m-2 h-1 under 1 sun irradiation. The results showed that Solar membrane steam evaporation can effectively harvest pure water through an increase in evaporation.

Automated Extraction of Orthorectified Building Layer from High-Resolution Satellite Images (고해상도 위성영상으로부터 건물 정위 레이어 자동추출)

  • Seunghee Kim;Taejung Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.3
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    • pp.339-353
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    • 2023
  • As the availability of high-resolution satellite imagery increases, improvement of positioning accuracy of satellite images is required. The importance of orthorectified images is also increasing, which removes relief displacement and establishes true localization of man-made structures. In this paper, we performed automated extraction of building rooftops and total building areas within original satellite images using the existing building height database. We relocated the rooftop sin their true position and generated an orthorectified building layer. The extracted total building areas were used to blank out building areas and generate true orthographic non-building layer. A final orthorectified image was provided by overlapping the building layer and non-building layer.We tested the proposed method with KOMPSAT-3 and KOMPSAT-3A satellite images and verified the results by overlapping with a digital topographical map. Test results showed that orthorectified building layers were generated with a position error of 0.4m.Through the proposed method, the feasibility of automated true orthoimage generation within dense urban areas was confirmed.

Elements for the Assessment of Collaborative Repositories Based on E-Metrics Measurement Standards (E-Metrics 측정지표에 기반한 협력형 레포지토리 평가요소 연구)

  • Chang, D.H.
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.20 no.4
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    • pp.159-172
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    • 2009
  • This paper strives to shed a light on current academic resource sharing initiatives, and seeks the measure for the cooperative information resource management. It first attempts to draw outcomes and suggestions on the basis of issues and implications identified through the analyses in the aspects of management, service, and infrastructure of academic resource sharing in other countries. For this job, research methods such as interviews and on/offline literature review are employed. Specific projects to be analyzed via literature and web site review, although not detailed in nature, are National Technical Information Service(NTIS) and The National Science Digital Library(NSDL) in the United States, Intute of United Kingdom, and Australian Research Repositories Online to the World(ARROW) of Australia. Next, the paper discusses such an issue as the orientation of national level academic resource sharing initiatives based on the comparison of characteristics of current academic resource sharing project. For this, a thorough comparison on background, outlines and characteristics of the projects and analysis on the specifics of each project were conducted as well.

Analysis of Network Security Policy Enforcement in Container Environments (컨테이너 환경에서의 네트워크 보안 정책 집행 분석)

  • Bom Kim;Seungsoo Lee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.6
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    • pp.961-973
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    • 2023
  • With the changes in the modern computing landscape, securing containerized workloads and addressing the complexities of container networking have become critical issues. In particular, the complexity of network policy settings and the lack of cloud security architecture cause various security issues. This paper focuses on the importance of network security and efficiency in containerized environments, and analyzes the security features and performance of various container network interface plugins. In particular, the features and functions of Cilium, Calico, Weave Net, and Kube-router were compared and evaluated, and the Layer 3/4 and Layer 7 network policies and performance features provided by each plugin were analyzed. We found that Cilium and Calico provide a wide range of security features, including Layer 7 protocols, while Weave Net and Kube-router focus on Layer 3/4. We also found a decrease in throughput when applying Layer 3/4 policies and an increase in latency due to complex processing when applying Layer 7 policies. Through this analysis, we expect to improve our understanding of network policy and security configuration and contribute to building a safer and more efficient container networking environment in the future.

Design of EMC countermeasures for radar signal processing board (레이다 신호처리 보드의 EMC 대책 설계)

  • Hong-Rak Kim;Man-hee Lee;Youn-Jin Kim;Seong-ho Park
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.5
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    • pp.41-46
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    • 2023
  • It is very important to meet the maximum detection range in a radar system. In order to meet the maximum detection Range, the sensitivity of the received signal of the radar system must be high. In addition, the dynamic range should be wide in the radar signal processing board. To meet these requirements, the signal processing board must be designed to be robust against external and internal noise. In particular, a design is required to minimize the effect of noise generated by various switching circuits inside the board on the received radar signal. In this paper, we derive the requirements of the signal processor board to meet the radar system performance and describe the design to meet the derived requirements. In addition, the EMC design to minimize the influence of noise input from the outside or generated from the inside is described. Confirm the secured performance through the test of the manufactured board.

A Study on Integrated Control and Safety Management Systems for LNG Membrane Storage Tank (멤브레인식 LNG 저장탱크용 통합제어안전관리시스템에 대한 연구)

  • Kim, Chung-Kyun
    • Journal of the Korean Institute of Gas
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    • v.14 no.2
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    • pp.40-46
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    • 2010
  • In this study, the integrated control and safety management system for a super-large LNG membrane storage tank has been presented based on the investigation and analysis of measuring equipments and safety analysis system for a conventional LNG membrane storage tank. The integrated control and safety management system, which may increase a safety and efficiency of a super-large LNG membrane storage tank, added additional pressure gauges and new displacement/force sensors at the steel anchor between an inner tank and a prestressed concrete structure. The displacement and force sensors may provide clues of a membrane panel failure and a LNG leakage from the inner tank. The conventional leak sensor may not provide proper information on the membrane panel fracture even though LNG is leaked until the leak detector, which is placed at the insulation area behind an inner tank, send a warning signal. Thus, the new integrated control and safety management system is to collect and analyze the temperature, pressure, displacement, force and LNG density, which are related to the tank system safety and leakage control from the inner tank. The digital data are also measured from measurement systems such as displacement and force of a membrane panel safety, LNG level and density, cool-down process, leakage, and pressure controls.

Numerical study on structural reinforced effects of concrete lining by spray-applied waterproofing membrane (차수용 박층 멤브레인 설치에 따른 콘크리트 라이닝의 구조적 보강효과에 관한 수치해석 연구)

  • Lee, Chulho;Lee, Kicheol;Kim, Dongwook;Choi, Soon-Wook;Kang, Tae-Ho;Chang, Soo-Ho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.3
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    • pp.551-565
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    • 2017
  • A spray-applied waterproofing membrane which consists of polymers has a relatively higher constructability and adhesion than the conventional sheet-type waterproofing materials. Additionally, the spray-applied waterproofing membrane generally shows a waterproofing ability as a composite structure with shotcrete or concrete lining. Because its purpose is waterproofing at the structure, structural effects were not well reported than waterproofing abilities. In this study, structural effects of the membrane-attached concrete lining were evaluated using 3-point bending test by the numerical method. From the analysis, a load-displacement behavior of the concrete lining and fracturing energy after yielding were compared with various conditions. Consequently, concrete lining with spray-applied waterproofing membrane shows higher flexural strength and fracturing energy than the single-layer concrete lining.

Effects of Arabinoxylan Rice Bran and Exercise Training on Immune Function and Inflammation Response in Lipopolysaccharide-stimulated Rats (유색미 겨 아라비녹실레인과 운동트레이닝이 Lipopolysaccharide 처치된 흰쥐의 면역인자 및 염증억제에 미치는 영향)

  • Son, Hee-Jeong;Kim, Hyung-Jun;Chae, Jeong-Hoon;Kwon, Hyung-Tae;Yeo, Hyo-Seong;Eo, Su-Ju;Leem, Yea-Hyun;Kim, Hyo-Jeong;Kim, Chang-Keun
    • Journal of Applied Biological Chemistry
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    • v.55 no.1
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    • pp.41-46
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    • 2012
  • Arabinoxylan (Ara) rice bran has been shown to be a potent biological response modifier as manifested by stimulation of different arms of the immune system. We examined the effects of Ara rice bran and exercise on the immune function and cytokines in lipopolysaccharide (LPS)-stimulated rats. As the results, tumor necrosis factor-${\alpha}$ as representative inflammatory cytokines showed a significantly lower in Ara supplement group, thus the Ara rice bran had a higher inhibitory activity than the both exercise and control group. However, 4 weeks of exercise training significantly increased inflammatory reactions rather than treatment with Ara in LPS-treated rats. The Ara rice bran acted to decrease the inflammatory reaction. These results suggest that the supplement of Ara rice bran is likely contribute to inflammation response and the Ara rice bran can be used as a possible safe alternative to the immunotherapeutic modalities.

Solid-liquid Separation Characteristics of Membrane Filter Press according to Coagulant Properties of Anaerobic Digestion Waste Water (혐기소화폐액의 응집제 특성에 따른 멤브레인 필터프레스의 고액분리 특성)

  • Han, Seong Kuk;Jung, Hee Suk;Song, Hyoung Woon;Kim, Ho;Ahn, Dae Hyun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.22 no.3
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    • pp.23-32
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    • 2014
  • Recently, it is increase in the processing of organic waste using anaerobic digestion. Therefore, the studies on the processing method for increasing the anaerobic digestion waste water. But it is very difficult to solid-liquid separation, because the characteristics of anaerobic digestion waste water. So this study evaluate solid-liquid separation efficiency of anaerobic digestion sludge using CST(Capillary Suction Time), TTF(Time to Filter). To address this problem, a membrane filter press of the lab scale was produced and the anaerobic digestion wastewater was applied to it. Polymer coagulants were found to be most suitable 7192PLUS and 1T60, It is necessary to minimum injection concentration is 7192PLUS (200 mg/L), 1T60 (100 mg/L). To evaluate dehydration efficiency, it was measured the moisture content of the dehydrated cake and suspended solids of decanted water. As a result, showed that a high removal efficiency of 97.4% when the solid-liquid separation using the membrane filter press. And the moisture content of the dehydrated cake was less than 65%.

Development of the Railway Abrasion Measurement System using Camera Model and Perspective Transformation (카메라 모델과 투시 변환에 의한 레일 마모도 측정 시스템 개발)

  • Ahn, Sung-Hyuk;Kang, Dong-Eun;Moon, Hyoung-Deuk;Park, So-Yeon;Kim, Man-Cheol
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1069-1077
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    • 2008
  • The railway abrasion measurement system have to satisfy two conditions to increase the measurement accuracy as follows. The laser region which is projected on the rail have to be extracted without the geometrical distortion. The mapping of the acquired laser region data on the rail profile have to be processed exactly. But, the conventional railway abrasion measurement system is deeply effected by the foreign substance( dust, rainwater, and so on ) on the railway or the sensitive response characteristic of the laser to the external measurement circumstance, and then the measurement errors arise from above factors. When the laser region is projected on the rail extracts from the acquired image, the interference of the light with the same frequency as the laser system occurs the serious problems. In the process of the mapping between the railway profile and the extracted laser region, the measurement accuracy is very highly effected by the geometrical distortion and the abnormal variation. In this Paper, we propose the novel method to increase the accuracy of the railway abrasion measurement dramatically. we designed and manufactured the high precision and fast image processing board with DSP Core and FPGA to measure the railway abrasion. The image processing board has the capability that the image of 1024X1280 from camera can be processed with the speed of 480 frame/sec. And, we apply the image processing algorithm base on the wavelet to extract the laser region is projected on the rail exactly. Finally, we developed high precision railway abrasion measurement system with the error range less than +/-0.5mm by which 2D image data is covered 3D data and mapped on the rail profile using the camera model and the perspective transform.

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