• Title/Summary/Keyword: hybrid systems

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A Study on the Integrated Hybrid Spatial Model for Knowledge Information Institutions - Focused on the User Space of Public Library - (지식정보시설의 통합형 하이브리드 공간 모형 연구 - 공공도서관 이용자 공간을 중심으로 -)

  • Hwang, Mee-Young
    • Korean Institute of Interior Design Journal
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    • v.24 no.3
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    • pp.146-155
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    • 2015
  • It is an undeniable fact that the modern people's interest in knowledge and information and their roles are some of the core factors used to define the modern society. Besides, as phenomena indicating and leading the modern society, we have fusion, hybrid and convergence, etc. that combine several different elements into a new one. Such changes in social, cultural and technological circumstances require a paradigm shift for the composition of knowledge and information facilities and space. However, more diversified and advanced recently, interfaces for the delivery of knowledge and information cause users to show new behaviors and even change the spatial concept with space composition elements hybridized. Especially for the space of libraries, it is necessary to access and utilize any forms of knowledge and information data (digital + analog) regardless of time and space limitations and approach with an integrated spatial concept likely to change flexibly depending on social demands. In this light, this study aims to make a basic proposal for sustainable integrated-type hybrid space for the space of a public library in this era of knowledge and information. Particularly, this study intends to seek a way to establish a hybrid space model that can effectively converge the most important factors of the space of libraries (human-space(network)-information). With 18 different cases, this study analyzed knowledge and information composition systems, knowledge and information delivery systems and users' space systems. As a result, this study extracted 3 kinds of models, an information-based model, a culture-based model and an education-based model, with the integrated hybrid space model of knowledge and information facilities

Improvement Performance of Truncated Type-II Hybrid ARQ Scheme and MRC Diversity Techniques using an Adaptive Modulation in DS -CDMA Cellular Mobile Communication System (DS-CDMA 셀룰라 이동통신 시스템에서 적응변조방식을 이용한 Truncated Type-II Hybrid ARQ 방식과 최대비 합성 다이버시티 기법에 의한 성능 개선)

  • 양재훈;김지웅;강희조
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.4
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    • pp.661-667
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    • 2001
  • This paper proposes a Truncated Type-II Hybrid ARQ scheme using an adaptive modulation system to achieve high throughput data transmission systems for DS-CDMA cellular mobile communication systems. In this paper, the adaptive modulation system analyzed in Nakagami (m-distribution) fading channel environment. The adaptive modulation system controls the modulation level and symbol rate according to the Nakagami fading parameter( m). When the received Eb/No is high or the Nakagami fading parameter m is high, the propose system selects higher modulation level and higher symbol rate to increase throughput. On the other hand, this system selects lower modulation level and lower symbol rate to prevent throughput performance degradation when the received Eb/No is low. The modulation method have been adopted QPSK 16QAM, 64QAM, 256QAM. Therefore, adaptive modulation systems with Truncated Type II Hybrid ARQ Scheme is proper for mobile and radio data communication system that require high reliability and delay-limited applications.

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Flamelet Modeling for Combustion Processes of Hybrid Rocket Engine (화염편 모델을 이용한 하이브리드 로켓의 연소과정 해석)

  • Lim, Jae-Bum;Kang, Sung-Mo;Kim, Yong-Mo;Yoon, Myung-Won
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2006.11a
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    • pp.237-240
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    • 2006
  • Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. Accordingly, the recent research efforts are focused on the improvement of engine efficiency and regressionrate in the hybrid rocket engine. The present study has numerically investigated the combustion processes and the flame structure in the hybrid rocket engine. The turbulent combustion is represented by the flamelet model and Low Reynolds number $k-{\varepsilon}$turbulent model is employed to reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect. Numerical results suggest that the present approach is capable of realistically simulating the combustion characteristics of the hybrid rocket engines.

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Flamelet Modeling for Combustion Processes of Hybrid Rocket Engine (화염편 모델을 이용한 하이브리드 로켓의 연소과정 해석)

  • Lim, Jae-Bum;Kim, Yong-Mo;Yoon, Myung-Won
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.245-248
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    • 2006
  • Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. Accordingly, the recent research efforts are focused on the improvement of engine efficiency and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the flamelet model and Low Reynolds number $k-{\varepsilon}$ turbulent model is employed to reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect. Based on numerical results, the detailed discussions have been made for the effects of oxygen injection methods and oxygen injection flow rate on flame structure and regression rate in the vortex hybrid rocket engines

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복합오염물질 처리를 위한 Hybrid PRB System

  • 김상태;강완협;문희선;민지은;조종수;박주양;김재영;박재우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.09a
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    • pp.129-132
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    • 2004
  • A hybrid permeable reactive barriers(hybrid PRBs) composed of Fe(II) PRB, biological PRB and sorptive PRB was investigated to treat groundwater with multiple contaminations. We performed batch, column and pilot tests to determine removal rates and design parameters of each PRB media, and operated two hybrid PRB systems with pilot-scale barriers in series. The pilot test of the hybrid PRB system with the combination of Fe(II), biological media and black shale showed multiple contaminations could be removed in ground water. Nitrate could be treated below 20 mg/L and Cr(VI) was treated down to 0.05 mg/L. TCE was degraded below 0.001 mg/L in system. The hybrid PRB system with a proper combination of PRBs could remediate ground water with multiple contaminations.

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A Hybrid Service Orchestration Framework based on BPEL4WS

  • Kim, Sung-Min
    • Journal of information and communication convergence engineering
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    • v.7 no.3
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    • pp.253-257
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    • 2009
  • As the value of B2B integration gets more importance and the business process becomes more complex, BPEL4WS standard has been focused for the solution of the problems which is based on web service technology. Many vendors implement the standard in their systems to integrate B2B and web service based inner-Enterprise Application(EA)s. But there is no way to use the standard to integrate non-web service based EAs, because the standard is designed only for Service Oriented Architecture (SOA) over web services. This paper proposes Hybrid Service Orchestration Framework to participate web services and also non-web service based EAs in the business process as a partner using BPEL4WS standard. The framework introduces Hybrid Service Architecture to represent non-web service based EAs as a service, so BPEL4WS could be used to integrate web services and non-web service based EAs. And the framework also introduces Hybrid Service Toolkit to support software level facilities. The paper also introduces Hybrid Orchestration System that is based on Hybrid Service Orchestration Framework.

Experimental Investigation of a Regression rate On Hybrid Rocket Engine

  • Park, J. W.;S. Krishnan;Lee, C. W.;M. W. Yoon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.524-527
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    • 2004
  • Hybrid rocket had many advantage with compared to solid and liquid rockets. However, the engines have not yet been used in practical rocket systems, due mainly to the disadvantage of hybrid combustion, such as low fuel regression rate. In this study, lab-scale hybrid motor was designed and manufactured. And the methods of regression rate improvement were considered. Test firings with thrusts up to 300 N were conducted with GOX and transparent PMMA. Thrust was calculated with the pressure of the combustion chamber and the regression rate was measured in with variation of oxidizer flow rate. The regression rates showed a strong dependency on GOX mass flux. The frequency analysis technique of the bulk-mode oscillation of motor was applied to a hybrid rocket motor and was based on the principle that this frequency was inversely proportional to the square root of the chamber volume. Several problems and solutions of operating hybrid rocket were presented.

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Hybrid Model Based Intruder Detection System to Prevent Users from Cyber Attacks

  • Singh, Devendra Kumar;Shrivastava, Manish
    • International Journal of Computer Science & Network Security
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    • v.21 no.4
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    • pp.272-276
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    • 2021
  • Presently, Online / Offline Users are facing cyber attacks every day. These cyber attacks affect user's performance, resources and various daily activities. Due to this critical situation, attention must be given to prevent such users through cyber attacks. The objective of this research paper is to improve the IDS systems by using machine learning approach to develop a hybrid model which controls the cyber attacks. This Hybrid model uses the available KDD 1999 intrusion detection dataset. In first step, Hybrid Model performs feature optimization by reducing the unimportant features of the dataset through decision tree, support vector machine, genetic algorithm, particle swarm optimization and principal component analysis techniques. In second step, Hybrid Model will find out the minimum number of features to point out accurate detection of cyber attacks. This hybrid model was developed by using machine learning algorithms like PSO, GA and ELM, which trained the system with available data to perform the predictions. The Hybrid Model had an accuracy of 99.94%, which states that it may be highly useful to prevent the users from cyber attacks.

Development of hybrid resin to reduce silica in borated water

  • Ramzan Akhtar ;Shahid Latif ;Syed Aizaz Ali Shah ;Shaukat Saeed ;Abdul Aziz
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2547-2555
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    • 2023
  • Amberlite IRN-78 resin was incorporated with iron to make a hybrid resin for the removal of silica from the borated water of nuclear power plants. The hybrid resin contained 0.84 wt % iron compounds upon pyrolysis. In batch experiments carried out at room temperature, 1 g of the hybrid resin removed ~60 ㎍ silica from 1 ppm borated water in ~120 min. The efficiency of the hybrid material increased with the resin quantity, decreased with silica concentration, and remained unchanged at different pH values. Freundlich and Temkin isothermal adsorption dominated the silica removal process and followed the pseudo-first-order and intra-particle diffusion mechanism simultaneously. The concentration of the leached iron remained appreciably under the safe limits of 200 ㎍/l during the experiments. This detailed study suggests the use of hybrid resin for the removal of silica from borated water streams and other similar systems.

Hybrid Genetic Algorithm or Obstacle Location-Allocation Problem

  • Jynichi Taniguchi;Mitsuo Gen;Wang, Xiao-Dong;Takao Yokota
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.191-194
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    • 2003
  • Location-allocation problem is known as one of the important problem faced in Industrial Engineering and Operations Research fielde. There are many variations on this problem for different applications, however, most of them consider no obstacle existing. Since the location-allocation problem with obstacles is very complex and with many infeasible solutions, no direct method is effective to solve it. In this paper we propose a hybrid Genetic Algorithm (hGA) method for solving this problem. The proposed hGA is based on Lagrangian relaxation method and Dijkstra's shortest path algorithm. To enhance the proposed hGA, a Fuzzy Logic Controller (FLC) approach is also adopted to auto-tune the GA parameters.

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