• 제목/요약/키워드: Technical System Theory

검색결과 246건 처리시간 0.023초

FAHP에 기반을 둔 기술창업교육서비스품질 평가 시스템 (Technical Entrepreneurship Education Service Quality Evaluation System based on FAHP)

  • 전향순;이상용
    • 디지털융복합연구
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    • 제13권10호
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    • pp.509-516
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    • 2015
  • 서비스의 특성은 무형성, 측정곤란성, 불가역성 등 품질 평가시 애매모호하고 불확실하다는 문제점이 있다. 공공 서비스의 일종인 기술창업교육도 이러한 서비스의 특징을 내포하고 있다. 본 논문에서는 기술창업교육서비스품질을 객관적으로 평가하기 위해 FAHP기법을 중심으로 요인을 계층구조로 작성하고 전처리 후, 삼각퍼지수 판단행렬에 입력, 가중치를 산출하여 요인의 상대적 중요도 및 우선순위를 도출하여 분석할 수 있는 TESE 시스템을 제안하였다. 제안된 시스템은 지속적이고 다양하게 변화하는 기술창업 환경에서의 정성적인 기술창업교육서비스품질 요인들을 정량적으로 분석한다. 분석 결과 주요 요인들의 상대적인 중요도에서 교육의 성과를 의미하는 결과품질이 41%로 가장 높게 나오는 등 효율적으로 요인을 평가 수 있어, 명확한 의사결정을 할 수 있음을 실험을 통하여 확인한다.

Nonlinear dynamic responses of cracked atomic force microscopes

  • Alimoradzadeh, M.;Akbas, S.D.
    • Structural Engineering and Mechanics
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    • 제82권6호
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    • pp.747-756
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    • 2022
  • This study presents the nonlinear free and forced vibrations of a cracked atomic force microscopy (AFM) cantilever by using the modified couple stress. The cracked section of the AFM cantilever is considered and modeled as rotational spring. In the frame work of Euler-Bernoulli beam theory, Von-Karman type of geometric nonlinear equation and the modified couple stress theory, the nonlinear equation of motion for the cracked AFM is derived by Hamilton's principle and then discretized by using the Galerkin's method. The semi-inverse method is utilized for analysis nonlinear free oscillation of the system. Then the method of multiple scale is employed to investigate primary resonance of the system. Some numerical examples are presented to illustrate the effects of some parameters such as depth of the crack, length scale parameter, Tip-Mass, the magnitude and the location of the external excitation force on the nonlinear free and forced vibration behavior of the system.

Operational Experience in DB "TERMIN"

  • Shaburova, Natalya N.
    • Journal of Information Science Theory and Practice
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    • 제7권3호
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    • pp.21-30
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    • 2019
  • Information about the formation and filling (in 2014 to 2016) of a terminological dictionary on electronics and radioengineering and collective work (in 2017 to 2018) with a data bank "TERMIN" is presented in this article. In purpose of creating an instrument of navigating the modern scientific-technical space a net of terms with set semantic links is described. This set is based on the analysis of terms' definitions (each term is checked for inclusion in the definitions of all other terms; the definitions were borrowed from reputable reference editions: encyclopedias, dictionaries, reference books). The created model of a system that consists of different information sources, in which it (information) is indexed by the terminology of Russian State Rubricator of Scientific and Technical Information rubrics and/or keywords, is described. There is an access for the search in all these sources in the system. Searching inquiries are referred to in the language of these rubrics or formulated by arbitrary terms. The system is to refer to information sources and give out relevant information. In accordance with this model, semantic links of various types, which allow expanding a search at different modalities of query, should be set among data bank terms. Obtained links will have to increase semantic matching, i.e., they can provide actual understanding of the meaning of the information that is being sought.

Analyzing the contact problem of a functionally graded layer resting on an elastic half plane with theory of elasticity, finite element method and multilayer perceptron

  • Yaylaci, Murat;Yayli, Mujgen;Yaylaci, Ecren Uzun;Olmez, Hasan;Birinci, Ahmet
    • Structural Engineering and Mechanics
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    • 제78권5호
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    • pp.585-597
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    • 2021
  • This paper presents a comparative study of analytical method, finite element method (FEM) and Multilayer Perceptron (MLP) for analysis of a contact problem. The problem consists of a functionally graded (FG) layer resting on a half plane and pressed with distributed load from the top. Firstly, analytical solution of the problem is obtained by using theory of elasticity and integral transform techniques. The problem is reduced a system of integral equation in which the contact pressure are unknown functions. The numerical solution of the integral equation was carried out with Gauss-Jacobi integration formulation. Secondly, finite element model of the problem is constituted using ANSYS software and the two-dimensional analysis of the problem is carried out. The results show that contact areas and the contact stresses obtained from FEM provide boundary conditions of the problem as well as analytical results. Thirdly, the contact problem has been extended based on the MLP. The MLP with three-layer was used to calculate the contact distances. Material properties and loading states were created by giving examples of different values were used at the training and test stages of MLP. Program code was rewritten in C++. As a result, average deviation values such as 0.375 and 1.465 was obtained for FEM and MLP respectively. The contact areas and contact stresses obtained from FEM and MLP are very close to results obtained from analytical method. Finally, this study provides evidence that there is a good agreement between three methods and the stiffness parameters has an important effect on the contact stresses and contact areas.

Fuzzy Applications in a Multi-Machine Power System Stabilizer

  • Sambariya, D.K.;Gupta, Rajeev
    • Journal of Electrical Engineering and Technology
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    • 제5권3호
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    • pp.503-510
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    • 2010
  • This paper proposes the use of fuzzy applications to a 4-machine and 10-bus system to check stability in open conditions. Fuzzy controllers and the excitation of a synchronous generator are added. Power system stabilizers (PSSs) are added to the excitation system to enhance damping during low frequency oscillations. A fuzzy logic power system stabilizer (PSS) for stability enhancement of a multi-machine power system is also presented. To attain stability enhancement, speed deviation ($\Delta\omega$) and acceleration ($\Delta\varpi$) of the Kota Thermal synchronous generator rotor are taken as inputs to the fuzzy logic controller. These variables have significant effects on the damping of generator shaft mechanical oscillations. The stabilizing signals are computed using fuzzy membership functions that are dependent on these variables. The performance of the fuzzy logic PSS is compared with the open power system, after which the simulations are tested under different operating conditions and changes in reference voltage. The simulation results are quite encouraging and satisfactory. Similarly, the system is tested for the different defuzzification methods, and based on the results, the centroid method elicits the best possible system response.

순시무효전력 보상에 의한 중성선 전류의 제거 (Eliminating the Neutral Current by the Instantaneous Reactive Power Compensation)

  • 김효성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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    • pp.131-133
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    • 1998
  • This paper, proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers $q_{q}$, $q_{r}$ were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of the three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storage element.

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사상체질 약재 정보 시스템 구축 (Construction of herbal medicine information system based on Sasang Constitution)

  • 진희정;김명근;김효정;유영법;김종열
    • 한국한의학연구원논문집
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    • 제14권1호
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    • pp.91-96
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    • 2008
  • Although the theory of Sasang Consititution is widely used in oriental clinic, there is only conceptual definition about the constitution not technical definition which is consented by every experts. In the present, the effect and different responses of constitutional medicines is the most widely accepted criteria among technical definitions. However, these medicines consist of several herbs which are included specific constitution. So, it is hard to define the characters about the Sasang Constitution through analysis of the medicines. In this paper, we collected the various information about the constitutional herbs, and constructed database and web application for accessing this information. It is useful and can be basis for finding the characteristics of constitutional medicines.

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An exact solution of dynamic response of DNS with a medium viscoelastic layer by moving load

  • S.A.H. Hosseini;O. Rahmani;H. Hayati;M. Keshtkar
    • Advances in materials Research
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    • 제12권3호
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    • pp.193-210
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    • 2023
  • This paper aims to analyze the dynamic response of a double nanobeam system with a medium viscoelastic layer under a moving load. The governing equations are based on the Eringen nonlocal theory. A thin viscoelastic layer has coupled two nanobeams together. An exact solution is derived for each nanobeam, and the dynamic deflection is achieved. The effect of parameters such as nonlocal parameter, velocity of moving load, spring coefficient and the viscoelastic layer damping ratio was studied. The results showed that the effect of the nonlocal parameter is significantly important and the classical theories are not suitable for nano and microstructures.

Effects of System Quality and Information Quality on the Use and Job Performance of an Enterprise Mobility Solution for a Mobile Office with a Consideration of Task Mobility and Task Interdependence as Control Variables

  • Yim, Sunjip;Shin, Minsoo
    • Asia pacific journal of information systems
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    • 제24권2호
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    • pp.115-140
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    • 2014
  • In a dynamic business environment, the enterprise mobility solution for a mobile office (EMS) has been adopted to increase the competitive edge of organizations. By using an EMS, performance is expected to be enhanced. However, the related literature has paid little interest to the impact of system quality in an EMS on the information quality produced by the system. On the basis of socio-technical theory, we posited that the system quality in an EMS influences information quality. In addition, we investigated the relationships between the above two qualities, use and job performance by considering task mobility and task inter-dependence as control variables. Survey respondents were from many industries using EMSs. The result of structural equation modeling shows that system quality positively affects information quality, and other relationships in the model are proven statistically significant. We also found that system quality has stronger impacts on use and job performance than information quality does in EMS. However, system quality does not affect use in case both task mobility and task inter-dependence exist. The theoretical and practical implications of the result are discussed in the paper.

쏘일네일링 공법을 적용한 영구 지하굴착 벽체의 설계사례 연구 (Design Case Study of Permanent Excavation Wall Using Soil Nailing System)

  • 박시삼;이제만;유찬호;김홍택
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 지반공학 공동 학술발표회
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    • pp.84-91
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    • 2005
  • In case of soil nailing system, there have been many attempts to expand into slope and temporary earth retaining system stabilization method since the first ground excavation earth retaining system construction in 1993. Recently, jointing wall, underground wall of buildings and excavation earth retaining wall, construction were increasingly applied for effective utilization of the limited underground space and land application maximized. However, the application of joining wall into retaining wall or building by temporary soil nailing system and design of permanent wall were performed by using Rankine earth pressure theory without considering the distribution of earth pressure in the soil nailing. In this study was performed to introduce the design case by 'Two-Body Translation mechanism (TBTM)' to be able to consider distribution of earth pressure in the soil nailing when designing the permanent jointing wall using soil nailing system for effective utilization of ground space. Also, this study attempts to evaluate the earth pressure change, decreasing effect of wall displacement and increasing effect of stability when advanced soil nailing system is constructed using $FLAC^{2D}$ ${\nu}er.$ 3.30 program and 'Two-Body Translation mechanism'.

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