• Title/Summary/Keyword: Hybrid Models

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A Dynamic Traffic Analysis Model for the Korean Expressway System using FTMS (FTMS 자료를 활용한 고속도로 Corridor 동적 분석)

  • Yu, Jeong-Hun;Lee, Mu-Yeong;Lee, Seung-Jun;Seong, Ji-Hong
    • Journal of Korean Society of Transportation
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    • v.27 no.6
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    • pp.129-137
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    • 2009
  • Operation of intelligent transport systems technologies in transportation networks and more detailed analysis give rise to necessity of dynamic traffic analysis model. Existing static models describe network state in average. on the contrary, dynamic traffic analysis model can describe the time-dependent network state. In this study, a dynamic traffic model for the expressway system using FTMS data is developed. Time-dependent origin-destination trip tables for nationwide expressway network are constructed using TCS data. Computation complexity is critical issue in modeling nationwide network for dynamic simulation. A subarea analysis model is developed which converts the nationwide O-D trip tables into subarea O-D trip tables. The applicability of the proposed model is tested under various scenario. This study can be viewed as a starting point of developing deployable dynamic traffic analysis model. The proposed model needs to be expanded to include arterial as well without critical computation burden.

HYBRID LIGHT DUTY VEHICLES EVALUATION PROGRAM

  • Trigui, R.;Badin, F.;Jeanneret, B.;Harel, F.;Coquery, G.;Lallemand, R.;Ousten, JP.;Castagne, M.;Debest, M.;Gittard, E.;Vangraefshepe, F.;Morel, V.;Baghli, L.;Rezzoug, A.;Labbe, J.;Biscalia, S.
    • International Journal of Automotive Technology
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    • v.4 no.2
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    • pp.65-75
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    • 2003
  • A HEV evaluation program, funded by ADEME, was carried out by a group of Laboratories of different specialties in order to evaluate and compare consumption, emission and component technologies of the three first HEVs put on the market (Toyota Prius, Nissan Tino and Honda Insight). This paper presents the results obtained until now. These results show good consumption and emission performance of the tested vehicles compared to conventional ones. The energy management seems to be globally the same for the three vehicles excepting for cold stans where the Insight allows a very earlier stop of the engine compared to the Tino and especially to the Prius. A mapping of the engine consumption of the Prius and the Insight was performed in order to furnish data for the simulation models. The Permanent Magnet motors of the Prius and Tino have different number of pair poles and then different emf at a given speed. The low emf values of the Prius allow operation at high speed with less field weakening control than for the Tino. The inverters of the Prius and the Tino, controlled by a PWM at respectively 5 kHz and 7 kHz switching frequency, are made of IGBTs with high commutation performances.

Determination of Thematic Roles according to Syntactic Relations Using Rules and Statistical Models in Korean Language Processing (한국어 전산처리에서 규칙과 확률을 이용한 구문관계에 따른 의미역 결정)

  • 강신재;박정혜
    • Journal of Korea Society of Industrial Information Systems
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    • v.8 no.1
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    • pp.33-42
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    • 2003
  • This paper presents an efficient determination method of thematic roles from syntactic relations using rules and statistical model in Korean language processing. This process is one of the main core of semantic analysis and an important issue to be solved in natural language processing. It is problematic to describe rules for determining thematic roles by only using general linguistic knowledge and experience, since the final result may be different according to the subjective views of researchers, and it is impossible to construct rules to cover all cases. However, our hybrid method is objective and efficient by considering large corpora, which contain practical usages of Korean language, and case frames in the Sejong Electronic Lexicon of Korean, which is being developed by dozens of Korean linguistic researchers. To determine thematic roles more correctly, our system uses syntactic relations, semantic classes, morpheme information, position of double subject. Especially by using semantic classes, we can increase the applicability of our system.

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Scientific Governance through Public Participation: Historical Epistemology of Divergent Positions in the Participatory Turn of STS (시민참여를 통한 과학기술 거버넌스: STS의 '참여적 전환' 내의 다양한 입장에 대한 역사적 인식론)

  • Hyun, Jae Hwan;Hong, Sung Ook
    • Journal of Science and Technology Studies
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    • v.12 no.2
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    • pp.33-79
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    • 2012
  • This paper first aims to reveal that, in the current trend of 'the participatory turn' in STS, there are divergent positions subtly different from each other, and that the understanding of these divergent positions can be significant to study the differences, similarities and interfaces between the various models of scientific governance discussed in STS and those in risk governance developed by risk studies. Secondly, this paper shows that theoretical differences among STS scholars on scientific governance and public participation goes back to the 1970s and 1980s, during which they first laid down the conceptual basis of STS. All ideas and theories have their own historicity. This article is about the 'historical epistemology' of the participatory turn of STS, and is to seek 'political epistemology' that can become a shared vision of STS.

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Molecular Modeling Study on Morphine Derivatives Using Density Functional Methods and Molecular Descriptors (범밀도 함수법과 Molecular Descriptor를 이용한 모르핀 유도체에 대한 분자 모델링 연구)

  • Cotua, Jose;Cotes, Sandra;Castro, Pedro;Castro, Fernando;Mora, Liadys
    • Journal of the Korean Chemical Society
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    • v.54 no.4
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    • pp.363-373
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    • 2010
  • Computational studies were carried out on the opiates morphine, heroin, codeine, pentazocine, and buprenorphine, under the density functional theory. The geometric parameters of the pharmacophore and substituents were evaluated at the B3LYP/6-31+G(d) level of theory. The electronic structure calculations were performed using the same hybrid functional at the B3LYP/6-311++G (d,p) level of theory. The atomic charges were obtained by Mulliken population analysis. Given the reported biological activity, calculated partition coefficients, and electronic and geometric analysis, pentazocine and buprenorphine were chosen as models for proposed analogues. These analogues were then studied and compared with the model molecules. The study reveals that the geometry and electronic structure of the pharmacophore remains consistent in the presence of different substituents. Because the proposed analogues preserve the studied properties of the model molecules, it is likely that these analogues display biological activity.

DEV&DESS-Based Real-Time Distributed Simulation Method Using DDS for Design Verification of Cyber-Physical Systems (CPS 설계 검증을 위한 DDS 및 DEV&DESS 기반의 실시간 분산 시뮬레이션 방법)

  • Kim, Jin Myoung;Lee, Hae Young;Chun, Ingeol;Kim, Won-Tae
    • Journal of the Korea Society for Simulation
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    • v.23 no.2
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    • pp.1-6
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    • 2014
  • CPS (cyber-physical systems) which consists of connected and diverse embedded systems and physical systems are a new paradigm. Traditional systems were usually considered to be passive and dumb parts in physical systems, but with CPS, we have to take into account what are being moved or changed in the physical systems. So, as increasing the complexity of CPS, potential errors in the systems also increase. In this paper, for enhancing the reliability of CPS, we exploit an executable-model-based design methodology and propose a distributed simulation method to verify the design of CPS. For the design of the systems including discrete and continuous factors, we apply DEV&DESS formalism and simulate models in distributed simulation environments through DDS middleware. We also illustrate the applications of CPS with our modeling tool.

A R&D Model for Korean SI Companies' International Competitiveness (World Class SI 기업으로의 도약 : 핵심 경쟁력 확보를 위한 R&D 모델 개발)

  • Lee, Yeon-Hee;Choi, Jin-Young
    • Journal of Information Technology Services
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    • v.2 no.2
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    • pp.15-29
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    • 2003
  • This thesis suggests a R&D model for Korean SI companies who aggressively drive oversea business to overcome domestic market limitation and to become world class SI players. Even though there have been a lot of discussions on IT technologies and new business models, scientific approach to a R&D model for SI companies is rare due to its natural distinctiveness from manufacturing and general service domain. Therefore, this will be a flagship thesis to keep up our study. As business market environment gets more competitive, major Korean SI players will be confronted with much more keen competition among themselves. And as they are willing to expand their oversea market presence, they can not help struggling against global SI players. So, here we are presenting SI players the reinforcement of R&D as one of the key components to build up their own core competencies. That is, SI players have to adopt and evaluate fast changing and complicated IT technologies at the right time, and to apply them into a real business with cost-effective service delivery and operation processes internally. The ultimate purpose of all of these activities is to offer a SI company the value added business model based on its innovative technical capabilities and well refined service deliver model. For this purpose, we suggests, SI company's R&D has to play an important role of emerging technology verification/evaluation/utilization, value added business model creation, future innovation lead, standard body participation, and effective service delivery and quality system development. To become a more effective R&D organization, hybrid R&D, in which central R&D and divisional sub R&D work together, is considered as an idea model. The reliability of the R&D model for Korean SI companies', here we suggest, has been checked by SI companies R&D specialists and on-site business people.

Channel Assignment for RFID Readers in Dense Reader Environments (밀집리더환경에서 RFID 리더를 위한 채널 할당)

  • Sohn, Surgwon
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.2
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    • pp.69-76
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    • 2013
  • Reader-to-reader interference in RFID system is occurred due to the use of limited number of frequencies, and this is the main cause of read rate reduction in the passive RFID tags. Therefore, in order to maximize the read rate under the circumstances of limited frequency resources, it is necessary to minimize the frequency interference among RFID readers. This paper presents a hybrid FDM/TDM constraint satisfaction problem models for frequency interference minimization problems of the RFID readers, and assigns optimal channels to each readers using conventional backtracking search algorithms. A depth first search based on backtracking are accomplished to find solutions of constraint satisfaction problems. At this moment, a variable ordering algorithm is very important to find a solution quickly. Variable ordering algorithms applied in the experiment are known as efficient in the graph coloring. To justify the performance of the proposed constraint satisfaction problem model, optimal channels for each readers in the passive UHF RFID system are allocated by using computer simulation satisfying various interference constraints.

A Comparison Study on the Parcel Transport Service Model-using High-Speed Passenger/Freight Mixed Train (여객/화물 고속복합열차를 이용한 소화물 운송 서비스 모델 비교연구)

  • Yum, ByongSoo;Ha, Ohkeun;Lee, Jinsun
    • Journal of the Korean Society for Railway
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    • v.18 no.5
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    • pp.471-480
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    • 2015
  • Reliance on road transport in domestic logistics can lead to intensified congestion and greenhouse gas emissions due to the rise in oil prices, any increase in logistics costs can have a high social cost. The government policy on Low Carbon Green Growth is seeking to take advantage of the railway system. However, existing railway transport logistics systems, for reasons such as low speed, low track capacity constraints, and the impossibility of implementing a Door to Door system, make it difficult to activate a railway logistics program. As a result of this study, a national R&D project to develop a High-Speed Passenger/Baggage Mixed Train(Hy-SoBex) utilizing the rail capacity constraints to overcome the difficulties of linking an air cargo and freight railway logistics system, we propose a variety of service models and select the optimal service model.

Interface Fracture and Crack Propagation in Concrete : Fracture Criteria and Numerical Simulation (콘크리트의 계면 파괴와 균열 전파 : 파괴규준과 수치모의)

  • 이광명
    • Magazine of the Korea Concrete Institute
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    • v.8 no.6
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    • pp.235-243
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    • 1996
  • The mechanical behavior ot concrete is strongly influenced by various scenarios of crack initiation and crack propagation. Recently. the study of the interface fracture and cracking in interfacial regions is emerged as an important field, in the context of the developement of high performance concrete composites. The crack path criterion for elastically homogeneous materials is not valid when the crack advances at an interface because. in this case, the consideration of the relative magnitudes of the fracture toughnesses between the constituent materials and the interface are involved. In this paper, a numerical method is presented to obtain the values of two interfacial fracture parameters such as the energy release rate and the phase angle at the tip of an existing interface crack. Criteria based on energy release rate concepts are suggested for the prediction of crack growth at the interfaces and an hybrid experimental-numerical study is presented on the two-phase beam composite models containing interface cracks to investigate the cracking scenarios in interfacial regions. In general, good agreement between the experimental results and the prediction from the criteria is obtained.