• Title/Summary/Keyword: 2 order system

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A Study of Knowledge Management System on Web 2.0 (웹 2.0 기반에서의 지식경영시스템에 관한 연구)

  • Lee, Hang
    • The Journal of Information Technology
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    • v.9 no.4
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    • pp.13-23
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    • 2006
  • The primary purposes of this study are to explain the relationship between Knowledge Management System(KMS) and Web 2.0, and understand the knowledge management system that assists a company and its organization on the whole in adopting knowledge management. In order to that, the studies associated with knowledge management and Web 2.0 are examined. Recently, the Web 2.0 that makes the interpersonal communication, and it is for Blogshpere is formed for communication. As a result of the analysis of correlation with the factors in creation of knowledge, and knowledge sharing, there are some correlations to each other.

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A Study on Real Condition Estimation for Fire Protection Safety Management System Builds (소방안전경영시스템 구축을 위한 실태평가에 관한 연구)

  • Kang, Gil-Soo;Choi, Jae-Wook
    • Fire Science and Engineering
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    • v.27 no.2
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    • pp.18-24
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    • 2013
  • Goverment and enterprises have been devoting a lot of dffort in order to prevent the loss of human and property due to a large, diversified fire, explosion, global warming and disasters caused by natural phenomena. But Enterprises came forward and running in the economy priority policy for profit-seeking until now in order to meet the macro purpose of quality improvement of national life and welfare promotion in company with National growth, as a result of lax risk management have had to endure the loss of precious lives and property. According to the '2007 Survey of public safety for the activation of the safety culture' of National Emergency Management Agency [NEMA], a insensitivity of safety in our society was surveyed 'a serious level'. In this study, surveyed need of 'step-by-step fire protection safety management system builds' in order to prevent fire safety accident and improvement of safety awareness level through a systematic management and real condition estimation of not only large business that can control risk management, but also small business that has a big risk to occur accident easily according to small budget and organization.

Dechlorination of High Concentrations of Tetrachloroethylene Using a Fixed-bed Reactor

  • Chang, Young-C.;Park, Chan-Koo;Jung, Kweon;Kikuchi, Shintaro
    • Journal of Environmental Health Sciences
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    • v.36 no.4
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    • pp.323-336
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    • 2010
  • We evaluated the properties of a fixed-bed column reactor for high-concentration tetrachloroethylene (PCE) removal. The anaerobic bacterium Clostridium bifermentans DPH-1 was able to dechlorinate PCE to cis-1,2-dichloroethylene (cDCE) via trichloroethylene (TCE) at high rates in the monoculture biofilm of an upflow fixed-bed column reactor. The first-order reaction rate of C. bifermentans DPH-1 was relatively high at $0.006\;mg\;protein^{-1}{\cdot}l{\cdot}h^{-1}$, and comparable to rates obtained by others. When we gradually raised the influent PCE concentration from $30\;{\mu}M$ to $905\;{\mu}M$, the degree of PCE dechlorination rose to over 99% during the operation period of 2,000 h. In order to maintain efficiency of transformation of PCE in this reactor system, more than 6 h hydraulic retention time (HRT) is required. The maximum volumetric dechlorination rate of PCE was determined to be $1,100\;{\mu}mol{\cdot}d^{-1}l$ of reactor $volume^{-1}$, which is relatively high compared to rates reported previously. The results of this study indicate that the PCE removal performance of this fixed-bed reactor immobilized mono-culture is comparable to that of a fixed-bed reactor mixture culture system. Furthermore, our system has the major advantage of a rapid (5 days) start-up time for the reactor. The flow characteristics of this reactor are intermediate between those of the plug-flow and complete-mix systems. Biotransformation of PCE into innocuous compounds is desirable; however, unfortunately cDCE, which is itself toxic, was the main product of PCE dechlorination in this reactor system. In order to establish a system for complete detoxification of PCE, co-immobilization of C. bifermentans DPH-1 with other bacteria that degrade cDCE aerobically or anaerobically to ethene or ethane may be effective.

Optimal Design of Graphite Sheet based Cryogenic Cooler Thermal Control System using Veritrek Software (Veritrek 소프트웨어를 활용한 그라파이트시트 기반 극저온 냉각기 열 제어 시스템 최적설계)

  • Bong-Geon Chae;Hye-In Kim;Hyun-Ung Oh
    • Journal of Aerospace System Engineering
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    • v.18 no.2
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    • pp.71-78
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    • 2024
  • During the initial thermal design process, determining the thermal effect of various design variables in a complex orbital thermal environment is time-consuming. To save time in the initial design phase, it is necessary to quickly derive optimal design parameters and predict the temperature. To address these challenges, Veritrek, a software specialized in optimal design using a reduced-order model (ROM), was released in 2018. In this paper, we utilized the Veritrek software to build a reduced-order model, conduct sensitivity analysis, and perform optimal design analysis for a graphite sheet-based cryogenic cooler thermal control system. The goal was to determine the optimal design values for the number of graphite sheet layers, radiator area, and thickness that would meet the allowable temperature of the cryogenic cooler.

Electric Discharge Analysis Using Nonlinarly-Coupled Equation of Electromagnetic Field and Charge Transport (방전현상 해석을 위한 전자장 및 전하이동 방정식의 비선형 결합 알고리즘)

  • Lee, Se-Yeon;Park, Il-Han;Lee, Se-Hee
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1494-1495
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    • 2006
  • A complete finite element analysis method for discharge onset process, which is governed and coupled by charge transport equation and electric field equation, was presented. The charge transport equation of first order was transformed into a second-order one by utilizing the artificial diffusion scheme. The two second-order equations were analyzed by the finite element formulation which is well-developed for second-order ones. The Fowler-Nordheim injection boundary condition was adopted for charge transport equation. After verifying the numerical results by comparing to the analytic solutions using parallel plane electrodes with one carrier system, we extended the result to blade-plane electrodes in 2D xy geometry with three carriers system. Radius of the sharp tip was taken to be 50 ${\mu}m$. When this sharp geometry was solved by utilizing the space discretizing methods, the very sharp tip was found to cause a singularity in electric field and space charge distribution around the tip. To avoid these numerical difficulties in the FEM, finer meshes, a higher order shape function, and artificial diffusion scheme were employed.

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Process -dynamic Model for Stock-fluid in a Pressurized Paper Machine Headbox (초지기 가압-헤드박스 내 지료유체의 공정-동특성모델)

  • 윤성훈
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.3
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    • pp.35-46
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    • 1999
  • Mathematical modeling provided a systematic analysis for the dynamic behavior of stock fluid in a paper machine pressurized headbox. Dynamic responses of liquid level, sheet basis weight and hydraulic pressure were predicted from the simulation model which represents the system. A unit step and asinusoidal wave load were considered as the input forcing functions in the headbox. Results are summarized as follows : 1. The dependence of sheet basis weight on liquid level in the pressurized-headbox was non -linear. 2. Liquid level in the head-box showed first-order lag with a unit step forcing to fluid input rate ; 3 . The amplitude of wave response of liquid level was inversely proportional to the time content for the sinusoidal input changes ; 4.Sheet basis weight showed second-order oscillating underamped responses for the step input load of flow rate ; 5. The damping factor in the second-order system was a function of air-pressure in the headbox ; and, 6. Dead-time existed in the measuring process for the headbox slice pressure.

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Generalization of equivalent lens conversion and third order aberration formulae of the generalized equivalent lens system (등가렌즈 변환의 일반화와 일반화된 등가렌즈의 3차수차식)

  • 이종웅;김건수
    • Korean Journal of Optics and Photonics
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    • v.7 no.4
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    • pp.305-313
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    • 1996
  • Lens design method by using equivalent lenses was already introduced, but the method has a limitaion that all lenses should be in the air. Therefore, we often get improper solution in designing cemented lenses. In this study, the lens conversion from thick lens to equivalent lens and its reversal was generalized without any preconditions, and the third order aberration fomulrae were derived for the generalized equivalent lens system. The generalized equivalent lens conversion were applied to typical cemented doublet and triplet, and they show that the third order aberrations of the generalized equivalent lenses have better agreements with their corresponding thick lenses than the previous conversion method.

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An Improved Stability Design of Steel Cable-Stayed Bridges using Second-Order Effect (2차효과를 고려한 강사장교의 개선된 좌굴해석)

  • Kyung Yong-Soo;Kim Nam-Il;Lee Jun-Sok;Kim Moon-Young
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.993-1000
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    • 2006
  • Practical stability design method of main members of cable-stayed bridges is proposed and discussed through a design example. For this purpose, initial tensions of stay cables and axial forces of main members are firstly determined using initial shaping analysis of bridges under dead loads. And then the effective buckling length using system elastic/inelastic buckling analysis and bending moments considering $P-{\delta}-{\Delta}$ effect by second-order elastic analysis are calculated for main girder and pylon members subjected to both axial forces and moments, respectively. Particularly, load combinations of dead and live loads, in which maximum load effects due to live loads are obtained, are taken into account and effects of live loads on effective buckling lengths are investigated.

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Vehicle Tracing Method Using Adaptive High Order Correlation Analysis (적응적 고차 상관 처리를 이용한 차량의 주행 궤적 검출법)

  • 장경영;오재응;좌등탁송
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.3
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    • pp.73-82
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    • 1996
  • Vehicle movement detection by high order correlation analysis of optical sensor array signals is introduced. The optical sensors observe the road which is assumed to be a non-uniform speckle-like texture. The measurement system is applicable to general robotic movement detection because : 1) It employs a non-contact measurement method, 2) The system can be made very compact, and 3) It enables approximation of the movement trace with a sequence of arcs instead of the conventional connection of simple line segments. In this work, we have looked into estimation of running trace of an autonomous vehicle by observing the ground pattern.

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Nonlinear Response Analyses for a Barge-Mounted Plant with Dolphin Mooring Systems in Irregular Waves (불규칙파 중에서 돌핀 계류된 바아지식 해상공장에 대한 비선형 응답 해석)

  • 이호영;신현경;염재선
    • Journal of Ocean Engineering and Technology
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    • v.14 no.4
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    • pp.1-8
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    • 2000
  • The time simulation of motion responses of dolphin-moored BMP in waves is presented. The equation of motion based on Cummin's theory of impulse responses are employed, and solved in time domain by using the Newmark $\beta$ method. The hydrodynamic coefficient and first order wave exciting forces involved in the equations are obtained from a three-dimensional panel method in the frequency domain. The second order wave drift forces and mooring for dolphin system are taken into account. As for numerical example, time domain analysis are carried out for a BMP in irregular wave condition.

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