• Title/Summary/Keyword: Protect Device

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A Design of Fire-Command Synchronous Satellite Pyrotechnic Circuit (점화 명령에 동조된 인공위성 파이로테크닉 회로 설계)

  • Koo, Ja Chun;Ra, Sung Woong
    • Journal of Korea Society of Industrial Information Systems
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    • v.18 no.5
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    • pp.81-92
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    • 2013
  • The satellite includes many release mechanisms such as solar array deployment, antenna deployment, cover to protect contamination in scientific equipment, pyro value of the propulsion subsytem, and bypass device in Li-Ion cell module. A drive the initiators is a critical to the successful mission because the initiators of release mechanism driving by the pyrotechnic circuit is operated in single short. The pyrotechnic circuit has to provide switching network for safety. A typical switching network has defect consisting of high current rating fire switch to handle switching transient current during fire the initiator. The pyrotechnic circuit is required some form of power conditioning to reduce the peak power demanded from the bus if the initiators are to be fired from the main bus. This paper design a pyrotechnic circuit synchronized to the fire-command to activate the fire switch to overcome use high current rating fire switch to handle switching transient current during fire the initiator. The pyrotechnic circuit provides a current limited widow pulse for fire current synchronized to the fire-command to insure that fire switch will only carry the current but never switch it. The current limited widow pulse for fire current can be possible to use low current rating and light mass switch in switching network. The current limit function in the pyrotechnic circuit reduces supply voltage to initiator and provides the effect of power conditioning function to reduce peak bus power. The pyrotechnic circuit to apply satellite development on geostationary orbit is verified the function by test in development model.

An Experimental Study on the Effect of Hydrogen Peroxide in the Treatment of Carbon Monoxide Poisoning (일산화탄소중독(一酸化炭素中毒)의 약물치료효과에 관(關)한 실험적(實驗的) 연구(硏究) -과산화수소(過酸化水素) 관장법(灌腸法)을 중심(中心)으로-)

  • Choi, D.W.;Yoo, K.Y.;Park, H.B.
    • Journal of Preventive Medicine and Public Health
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    • v.13 no.1
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    • pp.13-18
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    • 1980
  • The ultimate goal of treatment of carton monoxide poisoning is to promote dissociation of carboxyhemoglobin and to maintain arterial $PO_2$ above 50mmHg throughout the course of treatment to protect vital organs from damage caused by hypoxia. The hyperbaric chamber designed and manufactured for this purpose has obviousely made an enormous contribution and yet has several handicaps to be overcome by any means. These handicaps are: the financial impact to purchase the chamber (especially in a small, remote community), an extra manpower requirement to operate the device, limitation in the capacity of the chamber (one man type), and the possible hazard of oxygen intoxication and dysbarism. The primary objective of this study is to develope a new therapeutic measure as an alternative to the hyperbaric chamber when it is not available or contraindicated. The effect of intestinal perfusion with hydrogen peroxide has been studied by many investigators and was known to be an excellent way of extrapulmonary oxygen supply. the advantage of this method will include; 1) much more amount of oxygen is delivered to the tissue than one would expect from 100% saturation with oxygen at 1 ata, 2) the procedure is simple and most economical, 3) neither sophisticated equipment nor extra manpower is required. As a study preliminary to the clinical application, authors conducted a series of experiment to observe the effect of hydrogen peroxide enema on dissociation of carboxyhemoglobin in intoxicated rabbit blood. Using an animal gas chamber, 20 rabbits were exposed to CO gas of 6,000 ppm for 60 minutes. Ten rabbits of control group were given 10cc of warmed normal saline solution by reactal perfusion and for the other 10 of the experimental group, the same amount of 1% $H_{2}O_{2}$ solution was given by the same way. Two blood specimens were drawn from each rabbit: the first one immediately following the exposure and the second one after rectal perfusion, about 30 minutes after the first sampling. The result was as follows; 1) The decrease in carboxyhemoglobin concentration during the first 30 minutes in the control and experimental group were $18.18{\pm}4.49%\;and\;23.03{\pm}4.13%$ respectively shelving the significant difference (p<0.05) between the two groups. 2) Hemoglobin and hematocrit value showed no significant difference between two groups and not altered significantly by intestinal perfusion with $H_{2}O_{2}$.

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Development of Moisture Loss Index Based on Field Moisture Measurement using Portable Time Domain Reflectometer (TDR) for Cold In-place Recycled Pavements (휴대용 TDR 함수량계로 측정한 현장 함수비를 이용한 현장 상온 재활용 아스팔트 포장의 수분 감소계수 개발)

  • Kim, Yong-Joo;Lee, Ho-Sin David;Im, Soo-Hyok
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.139-145
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    • 2011
  • The practice of asphalt pavement recycling has grown rapidly over the decade, one of which is the cold in-place recycling with the foamed asphalt (CIR-foam) or the emulsified asphalt (CIR-emulsion). Particularly, in Iowa, the CIR has been widely used in rehabilitating the rural highways because it significantly increases the service life of the existing pavement. The CIR layer is typically overlaid by the hot mix asphalt (HMA) to protect it from water ingress and traffic load and obtain the required pavement structure and texture. Most public agencies have different curing requirements based on the number of curing days or the maximum moisture contents for the CIR before placing the overlay. The main objective of this study is to develop a moisture loss index that the public agency can use to monitor the moisture content of CIR layers in preparation for a timely placement of the wearing surface. First, the moisture contents were measured in the field using a portable time domain reflectometry (TDR) device. Second, the weather information in terms of rain fall, air temperature, humidity and wind speed was collected from the same location. Finally, a moisture loss index was developed as a function of initial moisture content, air temperature, humidity and wind speed. The developed moisture loss index based on the field measurements would help the public agency to determine an optimum timing of an overlay placement without continually measuring moisture conditions in the field.

A Study on the theory Substantial Compliance under UCP 600 (UCP 600상 상당일치론의 적용에 관한 연구)

  • Kang, Ho-Kyung;Lim, Mok-Sam
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.41
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    • pp.79-102
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    • 2009
  • L/C transaction, the most important issue for the seller and the buyer is the theory of documentary transaction and the theory of strict compliance which are the principles of L/C transactions. According to the leading cases in England and America where the practice of L/C transactions was created and developed, the descriptions of the commodities specified on all the documents which are submitted based on an L/C, should be identical to the descriptions of commodities specified in the L/C. And further, many leading cases of L/C continuously repeat to emphasize strict compliance. However, the recent leading cases in and out of the country show that the principle of strict compliance is being weakened. The leading cases in America show two trends of weakening the principle of strict compliance. That is, on the contrary to strict compliance, tends to apply substantial compliance (which puts more value on the substance of the documents). These leading cases reflect the attitudes of the judicial and the legislative authorization that don't want to approve formal approach to the commercial law. Recently, the Supreme Court of Korea is giving a decision on the principle of strict compliance, "The documents attached to an L/C should strictly comply with the conditions in the L/C, but it doesn't mean that they should be perfectly identical without any mistake in words. In case the bank can understand through reasonable care that a small mistake in words is too trivial to give different meaning or to give damage to the conditions of the L/C, the documents are regarded to comply with the conditions of the L/C. However, the judgment should be based on whether the difference between the documents and the L/C can be admitted by the international standard bank transaction practice or not." This decision tells that the principle of strict compliance is quite much modified so application of this modification can't be ignored. However, from the viewpoint of the party who requests to open an L/C, there is a criticism that a bank's arbitrary judgement can be involved. Therefore, reviewing the original purpose of L/C transactions (activating international transactions), the principle of strict compliance may be thought old-fashioned because it emphasizes a form, but in reality, for prompt transaction and payment, the principle of strict compliance should be observed in L/C transactions. And further, if a legislative device is prepared to systematically compensate for several side-effects, the principle of strict compliance will improve dynamic flow of prompt and low-costly L/C transactions. On the other hand, it will be able to protect the interested parties.

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The Architecture and Its Function of Tool server in MPEG-21 Multimedia Framework (MPEG-21 멀티미디어 프레임워크에서 툴 서버의 구조 및 기능)

  • 김광용;홍진우;김진웅
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.292-295
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    • 2003
  • This paper presents the architecture and its function of Tool server. MPEG-21 will enable all-electronic creation, delivery and trade of digital multimedia content and transparent usage of various content types on network device. Therefore, we can provide access to information and services from almost anywhere at anytime with various terminals and networks. In order to support multimedia delivery chain that contains content creation, production, delivery and consumption, we need some elements to identify, describe, manage and protect the contents. Thus, we define Digital Item Processing(DIP), Digital Item Adaptation(DIA) server and Tool server as primary objects of MPEG-21 multimedia framework. DIP provides a function which creates and consumes Digital Item(DI) as a kind of a digital object by user. DIA server adapts the original DI to the usage environment description sent from the terminal and transmits the adapted DI to the terminal. Tool sewer searches for a tool requested from DIP or DIA and downloads the best tool to DIP or DIA server. In this paper, we present how Tool server is organized and is used among 2 primary objects. The paper is structured as following: Section 1 briefly describes why MPEG-21 is needed and what MPEG-21 wants. We see the basic architecture of tool server and its functionality by each module in section 2. Section 3 explains a scenario that tool server transmits tool to DIP or DIA. The paper concludes in section 4.

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Reduction of Pollutant Concentrations in Urban Stormwater Runoff by Settling (침강에 의한 도시 강우 유출수 오염물질 저감 특성 분석)

  • Seo, Dongil;Kim, Jaeyoung
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.4
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    • pp.210-218
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    • 2016
  • The pollutant removal efficiencies of stormwater runoff by settling were analyzed using field samples collected in 4 different raining events in a test bed installed in the Gwanpyung-Cheon stream in Daejeon. A 1.8 m high with 30 cm diameter cylindrical settling device was used for the settling test by measuring concentration of TSS, TP and TN for time and height. The pollutants removal rate was relatively high in the first 4 hours while 24 hours seem to be necessary to reach steady state in pollutant concentrations. However, there were no considerable differences in concentrations for height at a given time. This indicates most of particulate pollutant in the test seems to show independent settling with no interference to each other. Much part of particle sizes were distributed in the range of $10{\sim}100{\mu}m$. Average particulate fractions of TP and TN were estimated as 52.4% and 23.5%, respectively. This results explain why TN is difficult to remove by simple settling. This study indicates that a simple settling can provide effective method to remove significant amount of TSS and TP effectively and this can be used to protect urban river water quality.

Optimum Design of Underwater Connector Hole Arrangement for Deep-sea Pressure Vessel Cover Plate (심해 압력용기 덮개판의 수중 커넥터홀 배치 최적설계)

  • Lee, Minuk;Park, Soung-Jea;Yeu, Tae-Kyeong;Ki, Hyong-Woo;Hong, Sup;Cho, Su-Gil;Jang, Jun-Yong;Lee, Tae Hee;Choi, Jong-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.12
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    • pp.1627-1633
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    • 2012
  • A deep-sea pressure vessel needs to protect the internal electrical equipment from the high external pressure. Thus, the pressure vessel should be designed to be watertight and structurally safe. In this study, a cylindrical-type pressure vessel comprising a hollow cylinder and cover plates at both ends is investigated. For communication between the internal electronic equipment and the external device, holes are bored on the cover plate to install underwater connectors. Considering the type of internal equipment and underwater connector specifications, multiple holes may be required. These holes can affect the structural safety of the pressure vessel cover plate. In this study, the optimum design of the hole arrangement in consideration of the structural safety of the cover plate was performed.

A Study on Analysis of Installation on the Actual State and Improvement about a Descending Life Line (완강기의 설치 실태 분석 및 개선에 관한 연구)

  • Choi, Yong-Hyuk;Park, Sung-Jin;Kim, Tae-Gu;Kim, Kwang-Il
    • Fire Science and Engineering
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    • v.22 no.1
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    • pp.105-114
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    • 2008
  • This study investigated problems found with the installation of a descending life line which is one of the compulsory fire escape apparatuses required by the revised "Fire Service Act" of 2006 for multi-use facilities and multistory buildings. It presents an analysis of the causes and improvement details for the problems classified by type of item. To achieve the purpose, the total 367 problem points are indicated. The problems of Installation are unsuitable window glass using the descending life line(34%), required passage device is not attached(23.7%), the installation location is with required operation(20%) and damaged descending life line(20%) were investigated. In particular, the study looks at the stress analysis range for cracking window glass which is required for people to escape in an emergency. People have questioned unsuitable window glass for using the descending life line among the problems with the installation. As a result of stress analysis, window glass thickness of the place where the descending life line is installed must be 3 or 6 mm. In addition, this study indicates substantial improvement measures for installing the descending life line so I will actually be used as a fire escape apparatus to protect human lives, and not just to formally meet the Fire Service Act.

The Effect of Digital Divide on the Use of Online Services in the Severely Disabled People: Focusing on Online Accessibility (중증장애인의 온라인 서비스 이용에 대한 디지털 정보격차의 영향: 온라인 접근성을 중심으로)

  • Jang, Changki;Sung, WookJoon
    • Informatization Policy
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    • v.27 no.3
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    • pp.56-81
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    • 2020
  • The purpose of this research is to empirically examine the effects of motivation and skill for digital devices and the Internet on the use of online services in the severely disabled people. In addition to the general effect of digital divide, particularly for the case of severely disabled people, the effects of physical and mental inconvenience of individuals were taken into account and the moderating effect was confirmed by classifying the groups that need help with online activities and those that do not. The 2018 Digital Divide Survey data of the National Information Society Agency was used for the study. As a research method, path analysis and multi-group analysis using a sequence access model to Internet use were performed. As a result, it was confirmed that even in the case of the disabled, the motivational factor affects the skill for digital device operation and Internet use, and this access skill sequentially affects the use of online services. In particular, it was found that the effect of strategic and technical skill for internet use is the most important for the use of online services for the disabled rather than the motivation or a simple operational skill for digital devices. In addition, it was found that even in the disabled group, those requiring help in using the Internet was more passive in using the online service than the rest in the group. The results of this study suggest the need for stronger capacity for physical access as well as support in building strategic and technical skills that enhance responsibilities and protect from risks in using the Internet among the people with disabilities.

A Study on the level of Recognition and Practices of 119 Emergency Medical Technician about Infection Control (119구급대원의 감염관리에 대한 인지도와 수행도 관계 연구)

  • Yun, Hyeong-Wan;Jung, Ji-Yeon
    • The Korean Journal of Emergency Medical Services
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    • v.12 no.3
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    • pp.99-113
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    • 2008
  • In order to protect Rescue 119 workers exposed on the spot from potential infection, this study identified their awareness and practices of infection control so that it could help preventing them from infection and also provide basic materials necessary for pre-hospital infection control. This study applied questionnaire survey to total 215 Rescue 119 workers at fire stations in Jeonbuk province, Jeonnam province and Gwangju city from July 14 to Sept. 14, 2006 for the benefit of data collection. The questionnaire about possible associations between awareness and practices of infection control consisted of total 46 times across 6 categories such as washing hands during emergency activities ; fluid therapy and injection ; respirator maintenance; individual hygienics ; disinfectant supplies and equipments maintenance ; and control of infectious wastes. And collected data were processed using SPSS statistic program to analyze frequency and percentage, mean and standard deviation, Pearson's correlation coefficient, t-test and one-way ANOVA. As a result, this study came to the following conclusions : In terms of awareness about infection control, our respondents showed highest awareness about infectious waste control, and also showed highest level of practices in washing hands during emergency activities. Throughout all domains, awareness means were higher than practice means. In particular, infectious waste control was the domain of significant differences between awareness and practices. In terms of associations between awareness and individual characteristics, it was found that female rescue worker group and hospital/general hospital career group (before joining the Rescue 119) showed significantly higher awareness on statistic level. In regard to associations between individual characteristics and practices, it was found that female rescue worker group showed higher level of practices than male group on statistic level. This study also analyzed correlations between rescue workers' awareness and practice of infection control. As a result, it was found that the higher awareness was in correlations with the higher practices across all 6 domains including washing hands. In addition, the higher awareness of a questionnaire item was in significantly positive correlations with the higher practice of other items. However, our respondents showed high awareness about anti-infection, but low practices in reality. This indicates necessity of devising possible solutions to improve the practices as much as awareness. Especially, it was noted that major reasons for insufficient practices of infection control guideline come from unhabituated practices and lack of supports for infection-preventing supplies and protective device (mask, etc). Hence, it is necessary to provide more infection-preventing supplies for local rescue workers sufficiently, in parallel with steady habituation of infection control. Furthermore, it is required to manage and study infection control policies even at pre-hospital step in efforts for effective infection control, education and activities.

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