• Title/Summary/Keyword: hybrid model

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A Study on the Thermal and Mechanical Characteristic of Hybrid Welded Ship Structure A-grade Steel (선체구조용 A급 강재의 하이브리드 용접에 대한 열 및 역학적 특성에 관한 연구)

  • Oh, Chong-In;Kim, Young-Pyo;Park, Ho-Kyung;Bang, Han-Sur
    • Journal of Ocean Engineering and Technology
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    • v.21 no.1 s.74
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    • pp.64-68
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    • 2007
  • Recently, there has been considerable research in the field of application of Laser-Arc hybrid welding for superstructures, such as ship-structures, transport vehicles etc. However, the study on heat distribution and welding residual stress of hybrid weld by numerical simulation leaves much to be desired. Therefore, in this study, an optimized welding condition and numerical simulation for hybrid welding, using previous numerical analysis to calculate the heat source for hybrid welding, has been analyzed. For this purpose, fundamental welding phenomena of the hybrid process, using Laser and, is investigated. In order to calculate temperature and residual stress distribution in hybrid welds, a finite element heat source model is developed on the basis of experimental results and characteristics of temperature. Residual stress distribution in hybrid welds are understood from the result of simulation, and compared with the experimental values.

Electrical properties of polyethylene composite films filled with nickel powder and short carbon fiber hybrid filler

  • Mironov, V.S.;Kim, Seong Yun;Park, Min
    • Carbon letters
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    • v.14 no.2
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    • pp.105-109
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    • 2013
  • Effects of the amount of nickel powder (Ni) in Ni-carbon fiber (CF) hybrid filler systems on the conductivity(or resistivity) and thermal coefficient of resistance (TCR) of filled high density polyethylene were studied. Increases of the resistivity and TCR with increasing Ni concentration at a given hybrid filler content were observed. Using the fiber contact model, we showed that the main role of Ni in the hybrid filler system is to decrease the interfiber contact resistance when Ni concentration is less than the threshold point. The formation of structural defects leading to reduced reinforcing effect resulted in both a reduction of strength and an increase of the coefficient of thermal expansion in the composite film; these changes are responsible for the increases of both resistivity and TCR with increasing Ni concentration in the hybrid filler system.

Design Optimization of Safety Barrier Consisting of Steel Rail and CFRP Post (강재 레일과 CFRP 기둥으로 이루어진 방호울타리의 최적화 설계)

  • Kim, Jung Joong;Kim, Seung-Eock
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.4 no.2
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    • pp.25-30
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    • 2013
  • In this study a hybrid safety barrier system consisting of steel rail and carbon fiber reinforced polymer (CFRP) post is considered. W hile CFRP post is selected for impact energy reflection due to its high strength, steel rail is selected for impact energy absorption due to its high ductility. A numerical model considering the elastoplastic behavior of steel is formulated to simulate the dynamic responses of the hybrid system subject to an impact load. A hybrid roadside guard rail system of steel rail and CFRP post is proposed and analyzed with a case study. The numerical model for the hybrid roadside guard rail system is used to find optimized design of the proposed hybrid system.

Active Vibration Control of a Beam Structure Using Hybrid Mount (하이브리드마운트를 이용한 빔 구조물의 능동진동제어)

  • 김승환;홍성룡;최승복
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.7
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    • pp.524-531
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    • 2003
  • This paper presents an active vibration control of a flexible beam structure using a hybrid mount which consists of elastic rubber and Piezoelectric material. After identifying stiffness and damping properties of the rubber and piezoelectric elements, a mechanical model of the hybrid mount is established. The mount model is then Incorporated into the beam structure, and the governing equation of motion is obtained in a state space. A sliding mode controller is designed in order to actively attenuate the vibration of the beam structure subjected to high frequency and small magnitude excitations. The controller is experimentally realized and control responses such as acceleration of the beam structure and force transmission through the hybrid mount are evaluated. In addition. a comparative work is done between the passive and hybrid mount systems.

Low Power Scheme Using Bypassing Technique for Hybrid Cache Architecture

  • Choi, Juhee
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.4
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    • pp.10-15
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    • 2021
  • Cache bypassing schemes have been studied to remove unnecessary updating the data in cache blocks. Among them, a statistics-based cache bypassing method for asymmetric-access caches is one of the most efficient approach for non-voliatile memories and shows the lowest cache access latency. However, it is proposed under the condition of the normal cache system, so further study is required for the hybrid cache architecture. This paper proposes a novel cache bypassing scheme, called hybrid bypassing block selector. In the proposal, the new model is established considering the SRAM region and the non-volatile memory region separately. Based on the model, hybrid bypassing decision block is implemented. Experiments show that the hybrid bypassing decision block saves overall energy consumption by 21.5%.

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

Analyzing the Effectiveness of Education Utilizing Hybrid Model (하이브리드 교수 모델을 이용한 수업 효과 분석)

  • Bong, Won Young;Jeong, Goo-Churl
    • The Journal of the Korea Contents Association
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    • v.16 no.2
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    • pp.513-524
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    • 2016
  • The purpose of this study was to open two classes with the name of $21^{st}$ Leadership, run with two different hybrid teaching styles which are hybrid LZ type and hybrid lz type, and compare them with each other in order to analyze their effectiveness of hybrid model of the subject. The subjects of this study were 64 students who took these classes, and statistical analysis were analyzed through SPSS 21.0 program. As a result of the analysis, first, there were significant development in terms of the knowledge of leadership in both LZ and lz model. but the result of final exam in the group lz was shown only significant development. Second, in the case of unconditional self-acceptance there was significant development only in the group lz. Third, the development of leadership skills was shown only in the group lz. Implications of these results were concluded that the lz is more suitable for the subject of $21^{st}$ Leadership because this model can provide much more opportunities to develope interpersonal relationship skill than LZ model. In addition, suggestions for future research were discussed.

Hybrid Control Model of MR Damper for Seismic Response Control of Adjacent Buildings (인접건축물의 지진응답 제어를 위한 MR 감쇠기의 복합제어 모델)

  • Kim, Gee-Cheol;Kang, Joo-Won;Chae, Seoung-Hun
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.2
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    • pp.101-110
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    • 2011
  • Many researchers have attempted to apply semi-active control systems in the civil engineering structures. Recently, magneto-rheological(MR) fluid dampers have been developed. This MR damper is one of semi-active dampers as a new class of smart dampers. This paper discusses the application of MR damper for seismic response control of adjacent buildings subjected to earthquake. Here, a controllable damping force of MR damper that is installed between adjacent buildings is applied to seismic response control. A hybrid model combines skyhook and groundhook control algorithm so that the benefits of each can be combined together. In this paper, hybrid control model are applied to the multi degree of freedom system representative of buildings in order to reduce seismic response of adjacent buildings. And the performance of hybrid control model is compared with that of others. It was demonstrated that hybrid control model or adjacent buildings with MR damper was effective for seismic response control of two adjacent buildings reciprocally.

Development of Finite Element Model of Hybrid III 5th Percentile Female Dummy (Hybrid III 5% 성인 여성 더미의 유한요소 모델 개발)

  • Yi, Sang-Il;Mohan, Pradeep K.;Kan, Cing-Dao Steve;Park, Gyung-Jin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.4
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    • pp.18-30
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    • 2010
  • As the automobile industry is developing, the number of deaths and injuries has increased. To reduce the damages from automobile accidents, the government of each country proposes experimental conditions for reproducing the accident and establishes the vehicle safety regulations. Automotive manufacturers are trying to make safer vehicles by satisfying the requirements. The Hybrid III crash test dummy is a standard Anthropomorphic Test Device (ATD) used for measuring the occupant's injuries in a frontal impact test. Since a real crash test using a vehicle is fairly expensive, a computer simulation using the Finite Element Method (F.E.M.) is widely used. Therefore, a detailed and robust F.E. dummy model is needed to acquire more accurate occupant injury data and behavior during the crash test. To achieve this goal, a detailed F.E. model of the Hybrid III 5th percentile female dummy is constructed by using the reverse engineering technique in this research. A modeling process is proposed to construct the F.E. model. The proposed modeling process starts from disassembling the physical dummy. Computer Aided Design (CAD) geometry data is constructed by three-dimensional (3-D) scanning of the disassembled physical dummy model. Based on the geometry data, finite elements of each part are generated. After mesh generation, each part is assembled with other parts using the joints and rigid connection elements. The developed F.E. model of dummy is simulated based on the FMVSS 572 validation regulations. The results of simulation are compared with the results of physical tests.

Genetic Algorithm based Hybrid Ensemble Model (유전자 알고리즘 기반 통합 앙상블 모형)

  • Min, Sung-Hwan
    • Journal of Information Technology Applications and Management
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    • v.23 no.1
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    • pp.45-59
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    • 2016
  • An ensemble classifier is a method that combines output of multiple classifiers. It has been widely accepted that ensemble classifiers can improve the prediction accuracy. Recently, ensemble techniques have been successfully applied to the bankruptcy prediction. Bagging and random subspace are the most popular ensemble techniques. Bagging and random subspace have proved to be very effective in improving the generalization ability respectively. However, there are few studies which have focused on the integration of bagging and random subspace. In this study, we proposed a new hybrid ensemble model to integrate bagging and random subspace method using genetic algorithm for improving the performance of the model. The proposed model is applied to the bankruptcy prediction for Korean companies and compared with other models in this study. The experimental results showed that the proposed model performs better than the other models such as the single classifier, the original ensemble model and the simple hybrid model.