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Measurement of the Size Distribution of Smoke Particles with Plastic Types Under Various Fire Conditions (다양한 화재조건에서 플라스틱 종류에 따른 연기입자의 크기분포 변화 측정)

  • Goo, Jaehark;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.31 no.6
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    • pp.8-15
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    • 2017
  • Most fire victims succumb to smoke inhalation, and fire smoke toxicity from interior materials is increasing with increased use of plastics. Large amounts of hazardous effects of smoke are related to deposition of smoke particles in respiratory tracts, and deposition characteristics are influenced by size distribution of particles. Thus, it is essential to know the size distribution of smoke particles from plastics for hazard analysis of fire smoke. In a recent study, it has been shown that size distributions of smoke particles from PP are different from wood in many aspects. In order to know whether other plastics show the same characteristics as PP, size distributions of smoke particles from four plastic materials (LDPE, PA66, PMMA, and PVC) were measured in real time under each fire type with various temperature and oxygen supply. In this study, smoke particles from different plastics were generated uniformly by using steady-state tube furnace method provided in ISO/TS 19700. Their size distributions were measured by using an electrical low pressure impactor (ELPI). Results of measurements showed that size distributions of smoke particles from these four plastic materials were similar to those from PP in many aspects. However, they were distinctively different from those of wood.

A Seamline Extraction Technique Considering the Characteristic of NDVI for High Resolution Satellite Image Mosaics (고해상도 위성영상 모자이크를 위한 NDVI 특성을 이용한 접합선 추출 기법)

  • Kim, Jiyoung;Chae, Taebyeong;Byun, Younggi
    • Korean Journal of Remote Sensing
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    • v.31 no.5
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    • pp.395-408
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    • 2015
  • High-resolution satellite image mosaics are becoming increasingly important in the field of remote sensing image analysis as an essential image processing to create a large image constructed from several smaller images. In this paper, we present an automatic seamline extraction technique and the procedure to generate a mosaic image by this technique. For more effective seamline extraction in the overlap region of adjacent images, an NDVI-based seamline extraction technique is developed, which takes advantage of the computational time and memory. The Normalized Difference Vegetation Index(NDVI) is an index of plant "greeness" or photosynthetic activity that is employed to extract the initial seamline. The NDVI can divide into manmade region and natural region. The cost image is obtained by the canny edge detector and the buffering technique is used to extract the ranging cost image. The seamline is extracted by applying the Dijkstra algorithm to a cost image generated through the labeling process of the extracted edge information. Histogram matching is also conducted to alleviate radiometric distortion between adjacent images acquired at different time. In the experimental results using the KOMPSAT-2/3 satellite imagery, it is confirmed that the proposed method greatly reduces the visual discontinuity caused by geometric difference of adjacent images and the computation time.

Application of Subsurface Flow Wetland using the Phragmites australis for Water Quality Improvement of the Agricultural Reservoi (농업용 저수지 수질개선을 위한 지하흐름 갈대 인공습지의 적용)

  • Nam, Gui Sook;Pae, Yo Sop;Kim, Hyung Joong;Lee, Sang Joon;Lee, Gwang Sik
    • Journal of Wetlands Research
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    • v.6 no.4
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    • pp.59-69
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    • 2004
  • Constructed wetlands are regarded as an important water treatment system for agricultural water quality improvement and management. The purpose of this study is to evaluate the application of subsurface flow wetland(SFW), using the Pharagmites australis as macrophytes, and to clarify the basic and essential factors to be considered in the construction and management of constructed wetlands. This study was carried out relatively short hydraulic residence time(HRT), 6hr ~ 72hr (3days), using eutrophic reservoir water with relatively low concentrations of influent and large quantity to be treated. The effluent satisfied the criteria of agricultural water quality. Removal efficiencies of Biochemical oxygen demand(BOD), Chemical oxygen demand(COD), Suspended solids(SS) and Chlorophyll a(Chl-a) were high in HRT 24hr, not any more significant increasement of removal efficiencies in HRT 48hr and 72hr. However, removal efficiencies of nitrogen and phosphorus increased as HRT increased, showing the highest efficiency at the 72hr of HRT in nitrogen, and 48hr in phosphorous. The SFW was very effective system for reservoir water quality improvement, and had the advantages of the reduction of purchasing cost to land required, lack of odors, and harmful insects, especially mosquito, the improvement of the scenic beauty and minimal risk of public exposure. Therefore, it was evaluated that the SFW was very available water treatment system for the water quality improvement of agricultural reservoir. However, it was need to consider with application of the SFW in high cost of construction and troublesome of management.

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Characteristics of MOCVD Cobalt on ALD Tantalum Nitride Layer Using $H_2/NH_3$ Gas as a Reactant

  • Park, Jae-Hyeong;Han, Dong-Seok;Mun, Dae-Yong;Yun, Don-Gyu;Park, Jong-Wan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.377-377
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    • 2012
  • Microprocessor technology now relies on copper for most of its electrical interconnections. Because of the high diffusivity of copper, Atomic layer deposition (ALD) $TaN_x$ is used as a diffusion barrier to prevent copper diffusion into the Si or $SiO_2$. Another problem with copper is that it has weak adhesion to most materials. Strong adhesion to copper is an essential characteristic for the new barrier layer because copper films prepared by electroplating peel off easily in the damascene process. Thus adhesion-enhancing layer of cobalt is placed between the $TaN_x$ and the copper. Because, cobalt has strong adhesion to the copper layer and possible seedless electro-plating of copper. Until now, metal film has generally been deposited by physical vapor deposition. However, one draw-back of this method is poor step coverage in applications of ultralarge-scale integration metallization technology. Metal organic chemical vapor deposition (MOCVD) is a good approach to address this problem. In addition, the MOCVD method has several advantages, such as conformal coverage, uniform deposition over large substrate areas and less substrate damage. For this reasons, cobalt films have been studied using MOCVD and various metal-organic precursors. In this study, we used $C_{12}H_{10}O_6(Co)_2$ (dicobalt hexacarbonyl tert-butylacetylene, CCTBA) as a cobalt precursor because of its high vapor pressure and volatility, a liquid state and its excellent thermal stability under normal conditions. Furthermore, the cobalt film was also deposited at various $H_2/NH_3$ gas ratio(1, 1:1,2,6,8) producing pure cobalt thin films with excellent conformality. Compared to MOCVD cobalt using $H_2$ gas as a reactant, the cobalt thin film deposited by MOCVD using $H_2$ with $NH_3$ showed a low roughness, a low resistivity, and a low carbon impurity. It was found that Co/$TaN_x$ film can achieve a low resistivity of $90{\mu}{\Omega}-cm$, a low root-mean-square roughness of 0.97 nm at a growth temperature of $150^{\circ}C$ and a low carbon impurity of 4~6% carbon concentration.

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Implications of Streptomyces coelicolor RraAS1 as an activator of ribonuclease activity of Escherichia coli RNase E (Streptomyces coelicolor RraAS1의 Eschechia coli RNase E의 RNA 분해작용에 대한 활성제로서 기능 암시)

  • Heo, Jihune;Seo, Sojin;Lee, Boeun;Yeom, Ji-Hyun;Lee, Kangseok
    • Korean Journal of Microbiology
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    • v.52 no.3
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    • pp.243-248
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    • 2016
  • RNase E (Rne) is an essential enzyme involved in the processing and degradation of a large portion of RNAs in Escherichia coli. The enzymatic activity of RNase E is controlled by regulators of ribonuclease activity, namely, RraA and RraB. Gram-positive bacterium Streptomyces coelicolor also contains homologs of Rne and RraA, designated as RNase ES (Rns), RraAS1, and RraAS2. In the present study, we investigated the effect of S. coelicolor RraAS1 on the ribonucleolytic activity of RNase E in E. coli. Coexpression of RraAS1 with Rne resulted in the decreased levels of rpsO, ftsZ, and rnhB mRNAs, which are RNase E substrates, and augmented the toxic effect of Rne overexpression on cell growth. These in vivo effects appeared to be induced by the binding of RraAS1 to Rne, as indicated by the results of co-immunoprecipitation analysis. These results suggested that RraAS1 induces ribonucleolytic activity of RNase E in E. coli.

A Study on the Threat of Biological Terrorism in modern society (현대사회의 환경변화에 따른 Bio-Terror의 위협요인 연구)

  • Kang, young-sook;Kim, Tae-hwan
    • Journal of the Society of Disaster Information
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    • v.1 no.1
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    • pp.3-26
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    • 2005
  • In recent years, there is growing concern about the potential use of biological agents in war or acts of terrorism accompanied an increased realization that rapid preparedness and response are needed to prevent or treat the human damage that can be caused by these agents. The threat is indeed serious, and the potential for devastating numbers of casualties is high. The use of agents as weapons, even on a small scale, has the potential for huge social and economic disruption and massive diversion of regional and national resources to combat the threat, to treat primary disease, and to clean up environmental contamination. Biological weapons are one of weapons of mass destruction (or mass casualty weapons, to be precise. since they do not damage non-living entities) that are based on bacteria, viruses, rickettsia, fungi or toxins produced by these organisms. Biological weapons are known to be easy and cheap to produce and can be used to selectively target humans, animals, or plants. Theses agents can cause large numbers of casualties with minimal logistical requirements (in wide area). The spread of disease cannot be controlled until there is awareness of the signs of infection followed by identification of agents; and if the organism is easily spread from person to person, as in the case of smallpox, the number of casualties could run into the tens of thousands. Biological weapons could be used covertly, there can be a lot of different deployment scenarios. A lot of different agents could be used in biological weapons. And, there are a lot of different techniques to manufacture biological weapons. Terrorist acts that make use of Biological Agents differ in a number of ways from those involving chemicals. The distinction between terrorist and military use of Biological Weapon is increasingly problematic. The stealthy qualities of biological weapons further complicate the distinction between terrorism and war. In reality, all biological attacks are likely to require an integrated response involving both military and civilian communities. The basic considerations when public health agencies establish national defence plan against bioterrorism must be 1) arraying various laws and regulations to meet the realistic needs, 2)education for public health personnels and support of concerned academic society, 3)information collection and cooperative project with other countries, 4)Detection and surveillance(Early detection is essential for ensuring a prompt response to biological or chemical attack, including the provision of prophylactic medicines, chemical antidotes, or vaccines) and 5) Response(A comprehensive public health response to a biological or chemical terrorist event involves epidemiologic investigation, medical treatment and prophylaxis for affacted persons, and the initiation of disease prevention or environmental decontamination measures). The purpose of this paper is providing basic material of preparedness and response for biological terrorism in modern society.

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Propensity Analysis of Terrorism and Political Leaders Countermeasures (정치지도자 요인테러 성향 분석과 대응방안)

  • Kang, Kyoung Soo;Song, Sang Wook
    • Journal of the Society of Disaster Information
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    • v.8 no.3
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    • pp.287-296
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    • 2012
  • This study is analysis of the existing domestic terrorism factors and suggest countermeasures for political leadership that can occur to the precautionary terror occasion of the presidential election approached 100 days in the future. Political terror caused mainly achieved peak of Ideology or social conflict by Politically alienated class. Common cause is most likely to occur when the party or the government want to attack a target or can not stand disadvantaged and lose that I suppert the party or the government. 21st century political terror is occurred with Misfits of complaints expressed or social conflict more frequency than attack used random people, new weqpon and bomb. It is interpreted that issued as a drastic measure from individual complaint because of increased polarization of wealth by separate into group and fallen law and order but also we are not familiar with the political compromises. Personal safety escort mission is essential condition of political activity that Absolute personal protection and to come up with a large number of voters for best result. Thus security guard ought to professional security activity depend on gathered situation, location and regional feature for perfect protection service.

A Research on Development Measures of Information Services for Construction Technology (건설기술 정보서비스 구축 방안에 관한 연구)

  • Ok, Hyun;Kim, Jin-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5707-5715
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    • 2015
  • Recently, construction industry has won an increasing number of orders for overseas construction projects, thereby achieving an external growth, but its competiveness is concentrated on the construction execution field. In particular, the plant field occupies most of the entire orders, which are concentrated regionally in the Middle East and Asia. In addition, low-cost orders are frequently caused by excessive competition. But its high value-added construction engineering(Below, CE) field's overseas market share and technological capacity are very low. Also, technological competiveness, in terms of order amount and other factors, is deepening in polarization between large CE companies and small and medium-sized CE firms. It is noted that the existing CE information systems mostly simply accumulate data such as design and specification standards and provide the information thereon to users, and thus have yet to provide the information essential for the CE and support such efforts. This study sought to prepare a system designed for sharing outstanding design documents information necessary for the CE industry, by category of construction so as to support the technological enhancement of the CE field. Toward that end, this study presented measures for constructing the system and services designed to exchange and share the outstanding design documents information and know-how by construction category necessary between ordering agencies and CE companies.

Study of the Dormitory Architecture of Governmental Secondary Schools in the Japanese Colonial Era (일제 강점기 관립 중등학교 기숙사 건축에 관한 연구)

  • Lee, Jeong-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.5355-5362
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    • 2014
  • This study reviewed the planning characteristics of dormitories for secondary schools in the Japanese Colonial Era by analyzing the architectural drawings collected by the National Archives of Korea. The dormitory was one of the essential facilities in secondary schools but there have been few studies in this area. The analysis items were the site plan and the planning characteristics of student bedrooms, dining hall, and supervisor's area, which were the main elements of the dormitory. The results of this study were summarized as follows. 1) Generally, the dormitory area was placed in the rear of buildings for teaching with a close connection. 2) The student bedroom wings were laid out in parallel to the south as a rule making the typical site plan pattern for a dormitory, whereas the other parts of dormitory, such as the dining hall and supervisor's area were placed in the site conditions. 3) Generally, the unit plans of bedrooms for Korean schools were the ondol type and were small in size, whereas those for Japanese were the tatami type and large in size with separate study and sleeping areas. 4) The dining hall annex was made up of a dining hall and kitchen-bathroom area in general. For Japanese schools, the school store area was added to these areas. The typical shapes of dining hall plans were narrow and long with an adjacent corridor, so the overall plan of the dining hall annex was like that of a single-corridor type block plan. 5) The supervisor's area was a smaller part of the dormitory but it was considered to be a symbolic part of the whole dormitory in site planning and design.

Vibration Analysis on the Inspection Equipment Frame of a Semiconductor Test Handler Picker (반도체 테스트 핸들러 픽커 검사장비 프레임에 대한 진동해석)

  • Kim, Young-Choon;Kim, Young-Jin;Kook, Jeong-Han;Cho, Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.4815-4820
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    • 2014
  • As semiconductor chips are on a small scale, large content and high integratation, it is essential to develop the device of pick and place at the system of the semiconductor test handler to ensure its high precision and durability. In this study, inspection equipment frame model of a semiconductor test handler picker was investigated by vibration analysis with the property of the natural frequency and harmonic response. As 3 kinds of analysis case models, the device of pick and place was located at the left side (Case 1), the center (Case 2) and the right side (Case 3) of the upper guideline. The range of natural frequencies until the 6th order on this frame model ranges from 80Hz to 500Hz. As the analysis of the harmonic response when the frame is resonant, Case 2 showed the maximum equivalent stress of 52.802 MPa more than Cases 1 or 3. Case 2 was the most intensive among the three cases. Using the analysis result of this study, the design of the frame model, which can be applied to the safe working environment of the system is believed to be possible.