• Title/Summary/Keyword: Systems analyses

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A Numerical Analysis of Soil-Pile Systems for Pile Load Tests at a Korean Site (국내 말뚝재하시험에 대한 지반-말뚝계의 수치해석)

  • Oh, Se-Boong;Ahn, Tae-Kyong;Choi, Yong-Kyu
    • Journal of Ocean Engineering and Technology
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    • v.13 no.1 s.31
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    • pp.94-104
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    • 1999
  • In order to evaluate the performance of axially of laterally loaded piles experimentaly, pile load tests can be carried out at the site Otherwise stress analyses or subgrade reaction analyses can solve the problem. In this study, stress analysis using FLAC code and subgrade reaction analyses using load transfer curves recommended by API(1993) were performed consistently on the basis of a result of site investigations, and the result of analyses was compared with the measured. As a result the behavior of pile heads was analyzed accurately for both axially and laterally loaded tests. Furthermore axially transferred loads were calculated appropriately for the measured and axial loads were transferred mainly mainly by the frictional resistance rather than by the tip resistance. Consequently, it can be commented that both analysis methods of soil-pile systems are applicable at teh objective site and that solutions may be more accurate if material properties from the site investigation are more explicit.

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New approach in design of seismic isolated buildings applying clusters of rubber bearings in isolation systems

  • Melkumyan, Mikayel G.
    • Earthquakes and Structures
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    • v.4 no.6
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    • pp.587-606
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    • 2013
  • The given paper presents a new approach in design of seismic isolation systems of base isolated buildings. The idea is to install not one big size rubber bearing under the columns and/or shear walls, or one by one with certain spacing under the load-bearing walls, but to install a group/cluster of small size bearings, in order to increase the overall effectiveness of the isolation system. The advantages of this approach are listed and illustrated by the examples. Also the results of analyses of some buildings where the approach on installation of clusters of rubber bearings was used in their isolation systems are given for two cases: i) when the analyses are carried out based on the provisions of the Armenian Seismic Code, and ii) when the time history analyses are carried out. Obtained results are compared and discussed. Paper also presents, as an example, detailed analysis and design of the 18-story unique building in one of the residential complexes in Yerevan. Earthquake response analyses of this building were carried out in two versions, i.e. when the building is base isolated and when it is fixed base. Several time histories were used in the analyses. Comparison of the obtained results indicates the high effectiveness of the proposed structural concepts of isolation systems and the need for further improvement of the Seismic Code provisions regarding the values of the reduction factors. A separate section in the paper dedicated to the design of high damping laminated rubber-steel bearings and to results of their tests.

Systems Studies and Modeling of Advanced Life Support Systems

  • Kang, S.;Ting, K.C.;Both, A.J.
    • Agricultural and Biosystems Engineering
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    • v.2 no.2
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    • pp.41-49
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    • 2001
  • Advanced Life Support Systems(ALSS) are being studied to support human life during long-duration space missions. ALSS can be categorized into four subsystems: Crew, Biomass Production, Food Processing and Nutrition, Waste Processing and Resource Recovery. The System Studies and Modeling (SSM) team of New Jersey-NASA Specialized Center of Research and Training (NJ-NSCORT) has facilitated and conducted analyses of ALSS to address systems level issues. The underlying concept of the SSM work is to enable the effective utilization of information to aid in planning, analysis, design, management, and operation of ALSS and their components. Analytical tools and computer models for ALSS analyses have been developed and implemented for value-added information processing. The results of analyses heave been delivered through the internet for effective communication within the advanced life support (ALS) community. Several modeling paradigms have been explored by developing tools for use in systems analysis. they include objected-oriented approach for top-level models, procedureal approach for process-level models, and application of commercially available modeling tools such as $MATLAB^{R}$/$Simulink^{R}$. Every paradigm has its particular applicability for the purpose of modeling work. an overview is presented of the systems studies and modeling work conducted by the NJ-NSCORT SSM team in its efforts to provide systems analysis capabilities to the ALS community. The experience gained and the analytical tools developed from this work can be extended to solving problems encountered in general agriculture.

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A Study on the Optimal Design of Urban Utility Systems (부하에 따른 도시기반 공급.처리시스템의 최적설계에 관한 연구)

  • Lee, Tae-Won;Kim, Yong-Ki
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.732-737
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    • 2001
  • The mathematical method was developed and numerical analyses were carried out with various parameters to provide substantial data for optimal design and operation of urban utility systems. The composition of systems and their specifications, such as co-generation system, heat pump system, incineration system and other heating and cooling system could be obtained through these analyses for various resource and energy requirements in urban area. As results the system constituents and operating characteristics, and their economic performances such as the value of objective function, initial and an operating costs were discussed for various load patterns. The effective system design method and the excepted effects of the several unused energy recovery systems were also briefly discussed with the variation of the buildings and facilities species and their capacities.

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Stochastic finite element analysis of structural systems with partially restrained connections subjected to seismic loads

  • Cavdar, Ozlem;Bayraktar, Alemdar;Cavdar, Ahmet;Kartal, Murat Emre
    • Steel and Composite Structures
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    • v.9 no.6
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    • pp.499-518
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    • 2009
  • The present paper investigates the stochastic seismic responses of steel structure systems with Partially Restrained (PR) connections by using Perturbation based Stochastic Finite Element (PSFEM) method. A stiffness matrix formulation of steel systems with PR connections and PSFEM and MCS formulations of structural systems are given. Based on the formulations, a computer program in FORTRAN language has been developed, and stochastic seismic analyses of steel frame and bridge systems have been performed for different types of connections. The connection parameters, material and geometrical properties are assumed to be random variables in the analyses. The Kocaeli earthquake occurred in 1999 is considered as a ground motion. The connection parameters, material and geometrical properties are considered to be random variables. The efficiency and accuracy of the proposed SFEM algorithm are validated by comparison with results of Monte Carlo simulation (MCS) method.

Characteristics of the Multi-Hydrogen Bonded Systems: DFT Description on the Solvated Electrons

  • Xu, Jun
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3265-3268
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    • 2013
  • The multi-hydrogen bonded systems with the solvated electrons are investigated at the B3LYP/6-311++$G^{**}$ basis set level. The symmetrical linear geometrical characteristic is common for the dimer systems, while for the tetramer system, the tetrahedron configuration is generated. The NBO charge analyses demonstrate that the multi-hydrogen-multi-electron (mH-ne) coupling exist in these anion systems, as is supported by the electrostatic potential and the molecular orbital analyses. The positive chemical shift value of the central hydrogen ($H_c$) and the negative chemical shift value of the terminal hydrogen ($H_t$) indicate that the $H_c$ is electronegative while the $H_t$ is electropositive, respectively. Strong coupling between two central hydrogen atoms is demonstrated by the large spin-spin coupling constants. The solvated electron donates significant contributions for the stability of these systems.

The Development of Performance Evaluation Measures for Logistics Information Systems on the Basis of BSC (균형성과표(BSC)를 이용한 물류정보시스템 성과평가지표 개발)

  • Kang, Hee-Suk;Kim, Sang-Hoon
    • Journal of Information Technology Services
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    • v.12 no.3
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    • pp.273-287
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    • 2013
  • The objective of this study is to empirically develop performance evaluation measures for LIS (logistics information systems) based upon BSC (balanced scorecard) model and determine the relative importance among four perspectives of BSC using AHP (analytic hierarchy process) methodology. Above all, forty nine probable measures for evaluating LIS performance were identified through reviewing the previous research related with SCM (supply chain management), logistics management, and information systems evaluation. And then, these probable measures were examined by means of coincidence analyses using three mutually exclusive criteria(validity of content, ease of measurement and reliability of measurement). Data for conducting the coincidence analyses were collected from LIS users and LIS development personnel. As the results of the coincidence analyses, it was found that 31 ones among 49 probable performance evaluation measures theoretically derived could be qualified for LIS performance evaluation. And AHP analysis showed that the weight of each perspective was respectively as follows : 46.8% for financial perspective, 31.3% for customer perspective, 14.8% for internal business process perspective, and 7.1% for learning and growth perspective. The academic contribution of this study is that performance evaluation measures for LIS could be systematically and empirically developed on the basis of BSC. Also, the results of this study are expected to be used as a practice guideline of evaluating and improving LIS.

The Difference Analyses between Users' Actual Usage and Perceived Preference: The Case of ERP Functions on Legacy Systems (사용자의 실제 이용과 인지된 선호도 차이 분석: 레거시 시스템의 ERP 기능을 중심으로)

  • Cho, Yong-Tak;Kim, Injai
    • The Journal of Information Systems
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    • v.23 no.1
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    • pp.185-202
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    • 2014
  • ERP, a typical enterprise application, helps companies to increase their productivity and to support their decision makings. ERP is composed of diverse functions that are optimized under PC environment, whereas the ERP applications on a mobile platform have many constraints such as a small screen, limited resolution, and computing power. Because all the functions of a ERP legacy system are not required for ERP on a mobile device, the core functions of the ERP system should be selected to increase system efficiency. In this study, two main methods were used; interviews and log analyses. The end users using a ERP system were interviewed for their perceptions, and log data analyses were made for the hitting number of specific ERP functions. The differences between the actual usage based on log data and users' cognitive preferences about ERP functions were analysed. Finally, the functional differences between users' perception and actual usage were suggested for some practical implications.

Counting Research Publications, Citations, and Topics: A Critical Assessment of the Empirical Basis of Scientometrics and Research Evaluation

  • Wolfgang G. Stock;Gerhard Reichmann;Isabelle Dorsch;Christian Schlogl
    • Journal of Information Science Theory and Practice
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    • v.11 no.2
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    • pp.37-66
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    • 2023
  • Scientometrics and research evaluation describe and analyze research publications when conducting publication, citation, and topic analyses. However, what exactly is a (scientific, academic, scholarly or research) publication? This article demonstrates that there are many problems when it comes to looking in detail at quantitative publication analyses, citation analyses, altmetric analyses, and topic analyses. When is a document a publication and when is it not? We discuss authorship and contribution, formally and informally published documents, as well as documents in between (preprints, research data) and the characteristics of references, citations, and topics. What is a research publication? Is there a commonly accepted criterion for distinguishing between research and non-research? How complete and unbiased are data sources for research publications and sources for altmetrics? What is one research publication? What is the unit of a publication that causes us to count it as "1?" In this regard, we report problems related to multi-author publications and their counting, weighted document types, the unit and weighting of citations and references, the unit of topics, and counting problems-not only at the article and individual researcher level (micro-level), but also at the meso-level (e.g., institutions) and macro-level (e.g., countries). Our results suggest that scientometric counting units are not reliable and clear. Many scientometric and research evaluation studies must therefore be used with the utmost caution.

SYSTEMS STUDIES AND MODELING OF ADVANCED LIFE SUPORT SYSTEM

  • Kang, S.;Ting, K.C.;Both, A.J.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11c
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    • pp.623-631
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    • 2000
  • Advanced Life Support Systems (ALSS) are being studied to support human life during long-duration space missions. ALSS can be categorized into four subsystems: Crew, Biomass Production, Food Processing and Nutrition, Waste Processing and Resource Recovery. The System Studies and Modeling (SSM) team of New Jersey-NASA Specialized Center of Research and Training (NJ-NSCORT) has facilitated and conducted analyses of ALSS to address systems level issues. The underlying concept of the SSM work is to enable the effective utilization of information to aid in planning, analysis, design, management, and operation of ALSS and their components. Analytical tools and computer models for ALSS analyses have been developed and implemented for value-added information processing. The results of analyses have been delivered through the Internet for effective communication within the advanced life support (ALS) community. Several modeling paradigms have been explored by developing tools for use in systems analysis. They include object-oriented approach for top-level models, procedural approach for process-level models, and application of commercially available modeling tools such as MATLAB$\^$(R)//Simulink$\^$(R)/. Every paradigm has its particular applicability for the purpose of modeling work. An overview is presented of the systems studies and modeling work conducted by the NJ-NSCORT SSM team in its efforts to provide systems analysis capabilities to the ALS community. The experience gained and the analytical tools developed from this work can be extended to solving problems encountered in general agriculture.

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