• Title/Summary/Keyword: large-scale systems

Search Result 1,879, Processing Time 0.027 seconds

Data for EIA and Its Presentation in Korea (한국의 EIA 자료와 그의 활용)

  • Lee, Hyoun-Young
    • Journal of Environmental Impact Assessment
    • /
    • v.2 no.2
    • /
    • pp.73-83
    • /
    • 1993
  • Increasing concern for the environment in Korea has led to the demand that major policies and large-scale development projects be subjected to detailed impact assessment. This paper reports on the state of data related to the prediction of the environmental impact (EIA) to emphasize the importance of data quality. Environmental impact statements (EIS) consulted with the Ministry of Environment of Korea were analyzed from 1981 through 1992. Many of assessors used existing data and collected supplementary data from field survey. Most of the results of EIA are presented directly or summarized on maps and as graphics. For the national purpose, large source of quality-controlled data such as atmospheric data have been developed, However, there are the deficiency in data to analyze the impact of human activity, and data gaps and incompatibilities among systems. Consequently, the development of data bank systems including computer database and remotely-sensed satellite data is required to improve the quality of data which are relevant to EIA. The data bank system should be organized meaningfully in minimum time with a least cost, and measurement standards must be made explicit. Geographical information systems (GIS) are applicable to the graphic presentation or to the impact prediction model.

  • PDF

Rapid-to-deploy reconfigurable wireless structural monitoring systems using extended-range wireless sensors

  • Kim, Junhee;Swartz, R. Andrew;Lynch, Jerome P.;Lee, Jong-Jae;Lee, Chang-Geun
    • Smart Structures and Systems
    • /
    • v.6 no.5_6
    • /
    • pp.505-524
    • /
    • 2010
  • Wireless structural monitoring systems consist of networks of wireless sensors installed to record the loading environment and corresponding response of large-scale civil structures. Wireless monitoring systems are desirable because they eliminate the need for costly and labor intensive installation of coaxial wiring in a structure. However, another advantageous characteristic of wireless sensors is their installation modularity. For example, wireless sensors can be easily and rapidly removed and reinstalled in new locations on a structure if the need arises. In this study, the reconfiguration of a rapid-to-deploy wireless structural monitoring system is proposed for monitoring short- and medium-span highway bridges. Narada wireless sensor nodes using power amplified radios are adopted to achieve long communication ranges. A network of twenty Narada wireless sensors is installed on the Yeondae Bridge (Korea) to measure the global response of the bridge to controlled truck loadings. To attain acceleration measurements in a large number of locations on the bridge, the wireless monitoring system is installed three times, with each installation concentrating sensors in one localized area of the bridge. Analysis of measurement data after installation of the three monitoring system configurations leads to reliable estimation of the bridge modal properties, including mode shapes.

Performance validation and application of a mixed force-displacement loading strategy for bi-directional hybrid simulation

  • Wang, Zhen;Tan, Qiyang;Shi, Pengfei;Yang, Ge;Zhu, Siyu;Xu, Guoshan;Wu, Bin;Sun, Jianyun
    • Smart Structures and Systems
    • /
    • v.26 no.3
    • /
    • pp.373-390
    • /
    • 2020
  • Hybrid simulation (HS) is a versatile tool for structural performance evaluation under dynamic loads. Although real structural responses are often multiple-directional owing to an eccentric mass/stiffness of the structure and/or excitations not along structural major axes, few HS in this field takes into account structural responses in multiple directions. Multi-directional loading is more challenging than uni-directional loading as there is a nonlinear transformation between actuator and specimen coordinate systems, increasing the difficulty of suppressing loading error. Moreover, redundant actuators may exist in multi-directional hybrid simulations of large-scale structures, which requires the loading strategy to contain ineffective loading of multiple actuators. To address these issues, lately a new strategy was conceived for accurate reproduction of desired displacements in bi-directional hybrid simulations (BHS), which is characterized in two features, i.e., iterative displacement command updating based on the Jacobian matrix considering nonlinear geometric relationships, and force-based control for compensating ineffective forces of redundant actuators. This paper performs performance validation and application of this new mixed loading strategy. In particular, virtual BHS considering linear and nonlinear specimen models, and the diversity of actuator properties were carried out. A validation test was implemented with a steel frame specimen. A real application of this strategy to BHS on a full-scale 2-story frame specimen was performed. Studies showed that this strategy exhibited excellent tracking performance for the measured displacements of the control point and remarkable compensation for ineffective forces of the redundant actuator. This strategy was demonstrated to be capable of accurately and effectively reproducing the desired displacements in large-scale BHS.

Beet western yellows virus (BWYV): Aspect of Outbreak and Survey, and First Complete Genome Sequence of a Korea Isolate of BWYV

  • Park, Chung Youl;Kim, Jeong-Sun;Lee, Hong Kyu;Oh, Jonghee;Lim, Seungmo;Moon, Jae Sun;Lee, Su-Heon
    • Research in Plant Disease
    • /
    • v.24 no.4
    • /
    • pp.276-284
    • /
    • 2018
  • In 2010, foliar symptoms were observed in the paprika leaves in Jinju city, Korea. Beet western yellows virus (BWYV) was identified in paprika by using the large-scale oligonucleotide chip assay. To investigate the occurrence of BWYV, a survey was performed on various crops, including paprika, from 2011 to 2014. Further, the presence of BWYV was consistently verified through literature survey from 2015 to 2017. BWYV infection has been identified in Solanaceae crops (bell pepper, hot pepper, and paprika), various weeds, and green peach aphids and it occurs on a nationwide scale. Cultivation using organic methods involved natural enemies and showed a high BWYV infection rate, which was more than that for conventional cultivation methods in greenhouse. The complete genome sequence of BWYV isolated from paprika was determined for the first time. The genome of the BWYV-Korea isolate consists of 5750 nucleotides and has six open reading frames. Sequence identity results showed maximum similarity between the BWYV-Korea isolate and the BWYV LS isolate (identity > 90%). This study is the first report of BWYV infecting paprika in Korea. The survey revealed that BWYV is naturalized in the domestic ecology of Korea.

Performance Evaluation of an Oxy-coal-fired Power Generation System - Thermodynamic Evaluation of Power Cycle (순산소 석탄 연소 발전 시스템의 성능 평가 - 동력 사이클의 열역학적 해석)

  • Lee, Kwang-Jin;Choi, Sang-Min;Kim, Tae-Hyung;Seo, Sang-Il
    • Journal of the Korean Society of Combustion
    • /
    • v.15 no.2
    • /
    • pp.1-11
    • /
    • 2010
  • Power generation systems based on the oxy-coal combustion with carbon dioxide capture and storage (CCS) capability are being proposed and discussed lately. Although a large number of lab scale studies for oxy-coal power plant have been made, studies of pilot scale or commercial scale power plant are not enough. Only a few demonstration projects for oxy-coal power plant are publicized recently. The proposed systems are evolving and various alternatives are to be comparatively evaluated. This paper presents a proposed approach for performance evaluation of a commercial 100 MWe class power plant, which is currently being considered for 'retrofitting' for the demonstration of the concept. The system is configurated based on design and operating conditions with proper assumptions. System components to be included in the discussion are listed. Evaluation criteria in terms of performance are summarized based on the system heat and mass balance and simple performance parameters, such as the fuel to power efficiency and brief introduction of the second law analysis. Also, gas composition is identified for additional analysis to impurities in the system including the purity of oxygen and unwanted gaseous components of nitrogen, argon and oxygen in air separation unit and $CO_2$ processing unit.

Classification of Major Barriers to the Application of RFID Systems and a Guideline for Successful Application (RFID 시스템 도입의 주요 장애요인 분류와 성공적 도입을 위한 가이드라인)

  • Youm, Se-Kyoung;Cho, Sung-Ku
    • Journal of the Korea Safety Management & Science
    • /
    • v.10 no.2
    • /
    • pp.143-154
    • /
    • 2008
  • With the recent rapid growth of RFID technologies, the Application of RFID systems into the medical or the military industries as well as into the distribution and logistics industry are now attempted continuously. The government and private sectors plan to carry out various small and large scale projects related to RFID systems. However, many companies attempting to apply RFID systems applications into their organizations are encountering many several difficulties because of the lack of installation experience and the absence of an useful guideline. This paper focuses on identification and classification of typical barriers to the successful application of RFID systems according to the five-step method of system application process. Moreover a "barrier map" is produced by conducting a survey and interviews by specialists. In addition, a practical guideline to overcome such barriers is presented and discussed.

A Research Plan on the Application of Systems Engineering to Light Rail Transit Project (경량전철사업 시스템엔지니어링 적용기술 개발 전략)

  • Han, Seok-Youn;Choie, Yo-Chel;Park, Ki-Jun;Lee, Ahn-Ho
    • Proceedings of the KSR Conference
    • /
    • 2011.05a
    • /
    • pp.1604-1611
    • /
    • 2011
  • Light Rail Transit(LRT) is a large scale complex system which combines rolling stocks, power supply, signal communication, tracks & stations, and hundreds of billions of wons per project are spent for construction. Therefore efficient integration of sub-systems is very important. The systems engineering is a good method to reduce the cost and risk of LRT project. In this paper, we introduce a research plan on the application of systems engineering to LRT project. We, Korea Railroad Research Institute(KRRI), launched a research program with 4 companies, which is support by the governmen and project period is 4.5 years. Main research topic is to develop the technology for the application of systems engineering technical process to LRT project based on ISO/IEC 15288.

  • PDF

Hybrid Modeling and Control for Platoon Maneuvers in Automated Highway Systems (군집주행 기동을 위한 하이브리드 모델링 및 제어기 설계)

  • 전성민;최재원
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.8 no.12
    • /
    • pp.1014-1022
    • /
    • 2002
  • An objective of Automated Highway Systems (AHS) is to increase the safety and throughput of the existing highway infrastructure by introducing traffic automation. AHS is an example of a large scale, multiagent complex dynamical system and is ideally suited for a hierarchical hybrid controller. We discuss a design issue of efficient hybrid controllers for the platoon maneuvers on AHS. For the modeling of a hybrid system including the merge and split operations, a safety distance policy is introduced for the merge and split operations. After that, the platoon system will be modeled by a hybrid system In addition, a hybrid controller for the proposed merge and split operation models is presented. Finally, the performance of the proposed hybrid control scheme is demonstrated via scenarios for platoon maneuvers.

Passivity-based Control Approach of Exciter and Governor Systems for Synchronous Electric Generators (Passivity 기반 동기 발전기의 여자기 및 조속기 시스템의 제어 기법)

  • Cho, Hyun Cheol
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.67 no.4
    • /
    • pp.561-568
    • /
    • 2018
  • Passivity theory is significantly applied to analyze stability of nonlinear dynamic systems and construct its stable control systems. This paper presents a passivity based control design approach for exciters and governors which are employed to regulate the terminal voltage and the rotor velocity of synchronous generator systems in industry fields. We consider the IEEE type 1 exciter and the gas turbine (GT) governor models respectively in this paper. We first carry out a passivity analysis for exciter and governor control systems, which are numerically obtained from its mathematical models. And then its control parameters are selected to assure passivity conditions in a design procedure. Lastly, we investigate numerical simulations to demonstrate reliability of the proposed control approach against large-scale generators with parameter changes.

Performance Analysis of Group Recommendation Systems in TV Domains

  • Kim, Noo-Ri;Lee, Jee-Hyong
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.15 no.1
    • /
    • pp.45-52
    • /
    • 2015
  • Although researchers have proposed various recommendation systems, most recommendation approaches are for single users and there are only a small number of recommendation approaches for groups. However, TV programs or movies are most often viewed by groups rather than by single users. Most recommendation approaches for groups assume that single users' profiles are known and that group profiles consist of the single users' profiles. However, because it is difficult to obtain group profiles, researchers have only used synthetic or limited datasets. In this paper, we report on various group recommendation approaches to a real large-scale dataset in a TV domain, and evaluate the various group recommendation approaches. In addition, we provide some guidelines for group recommendation systems, focusing on home group users in a TV domain.