• 제목/요약/키워드: Technical System Theory

검색결과 246건 처리시간 0.032초

Influence of initial stresses on the critical velocity of the moving load acting in the interior of the hollow cylinder surrounded by an infinite elastic medium

  • Akbarov, Surkay D.;Mehdiyev, Mahir A.
    • Structural Engineering and Mechanics
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    • 제66권1호
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    • pp.45-59
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    • 2018
  • The bi-material elastic system consisting of the pre-stressed hollow cylinder and pre-stresses surrounding infinite elastic medium is considered and it is assumed that the mentioned initial stresses in this system are caused with the compressing or stretching uniformly distributed normal forces acting at infinity in the direction which is parallel to the cylinder's axis. Moreover, it is assumed that on the internal surface of the cylinder the ring load which moves with constant velocity acts and within these frameworks it is required to determine the influence of the aforementioned initial stresses on the critical velocity of the moving load. The corresponding investigations are carried out within the framework of the so-called three-dimensional linearized theory of elastic waves in initially stresses bodies and the axisymmetric stress-strain state case is considered. The "moving coordinate system" method is used and the Fourier transform is employed for solution to the formulated mathematical problem and Fourier transformation of the sought values are determined analytically. However, the originals of those are determined numerically with the use of the Sommerfeld contour method. The critical velocity is determined from the criterion, according to which, the magnitudes of the absolute values of the stresses and displacements caused with the moving load approaches an infinity. Numerical results on the influence of the initial stresses on the critical velocity and interface normal and shear stresses are presented and discussed. In particular, it is established that the initial stretching (compressing) of the constituents of the system under consideration causes a decrease (an increase) in the values of the critical velocity.

E-voting Implementation in Egypt

  • Eraky, Ahmed
    • Journal of Contemporary Eastern Asia
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    • 제16권1호
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    • pp.48-68
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    • 2017
  • Manual elections processes in Egypt have several negative effects; that mainly leads to political corruption due to the lack of transparency. These issues negatively influence citizen's participation in the political life; while electronic voting systems aim to increase efficiency, transparency, and reduce the cost comparing to the manual voting. The main research objectives are, finding the successful factors that positively affects E-voting implementation in Egypt, in addition of finding out the reasons that keep Egyptian government far from applying E-voting, and to come up with the road map that Egyptian government has to take into consideration to successfully implement E-voting systems. The findings of the study suggest that there are seven independent variables affecting e-voting implementation which are; leadership, government willingness, legal framework, technical quality, awareness, citizen's trust in government and IT literacy. Technology-Organization-Environment (TOE) theory was used to provide an analytical framework for the study. A quantitative approach (i.e., survey questionnaire) strategy was used to collect data. A random sampling method was used to select the participants for the survey, whom are targeted voters in Egypt and have access to the internet, since the questionnaire was distributed online and the data is analyzed using regression analysis. Practical implications of this study will lead for more citizen participation in the political life due to the transparency that E-voting system will create, in addition to reduce the political corruption.

10 kW급 수평축 풍력 터빈 로터 블레이드의 공력 설계 (Aerodynamic Design of 10 kW-level HAWT Rotor Blades)

  • 장세명;이장호
    • 한국항공우주학회지
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    • 제35권10호
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    • pp.884-890
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    • 2007
  • 10 kW급 수평축 풍력 터빈의 로터를 개발하기 위해 블레이드의 공력 설계 절차를 체계적으로 연구하고 실행하였다. 운동량 이론과 깃 요소법에 근거한 역 설계 방법을 확립하고, 이를 이용하여 주어진 공력 분포에 따른 근사 최적 형상을 설계하였다. 설계된 형상은 공군사관학교의 풍동에서 검증되었고, 본 설계를 통하여 실제로 제작된 로터로부터 실측 데이터를 취득하여 비교하였다. 본 연구를 통하여 저자들은 풍력 터빈 블레이드의 설계 방법에 대한 체계적 기술을 축적하고, 나아가 같은 방법을 중대형 시스템으로 확장하기 위한 기술적 노하우를 취득하였다.

Adaptive Hypermedia for eLearning: An Implementation Framework

  • Dutta, Diptendu;Majumdar, Shyamal;Majumdar, Chandan
    • 한국멀티미디어학회논문지
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    • 제6권4호
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    • pp.676-684
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    • 2003
  • eLearning can be defined as an approach to teaching and teaming that utilises Internet technologies to communicate and collaborate in an educational context. This includes technology that supplements traditional classroom training with web-based components and learning environments where the educational process is experienced online. The use of hypertext as an educational tool has a very rich history. The advent of the internet and one of its major application, the world wide web (WWW), has given a tremendous boost to the theory and practice of hypermedia systems for educational purposes. However, the web suffers from an inability to satisfy the heterogeneous needs of a large number of users. For example, web-based courses present the same static teaming material to students with widely differing knowledge of the subject. Adaptive hypermedia techniques can be used to improve the adaptability of eLearning. In this paper we report an approach to the design a unified implementation framework suitable for web-based eLearning that accommodates the three main dimensions of hypermedia adaptation: content, navigation, and presentation. The framework externalises the adaptation strategies using XML notation. The separation of the adaptation strategies from the source code of the eLearning software enables a system using the framework to quickly implement a variety of adaptation strategies. This work is a part of our more general ongoing work on the design of a framework for adaptive content delivery. parts of the framework discussed in this paper have been imulemented in a commercial eLearning engine.

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α-β 필터를 사용한 위상배열 레이더의 실표적 추적 정확도 평가 알고리듬 연구 (A Study for Assessment of Track Accuracy of Phased Array Radar Associated with α-β Filter)

  • 신상진;김완규
    • 한국전자파학회논문지
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    • 제26권9호
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    • pp.828-836
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    • 2015
  • 본 논문은 위상배열 레이더를 사용하여 실제표적을 추적하였을 때 추적 정확도를 평가하기 위한 알고리듬 연구이다. 실표적에 대한 추적 정확도를 평가하기 위해서는 실표적 위치에 대한 정보가 있어야 하지만, 시험비용 및 시험시간의 증대로 인해 위상배열 레이더에서 획득된 데이터만을 사용하여 실표적의 정확도를 평가하는 알고리듬을 제시한다. 이러한 평가 알고리듬은 위상배열 레이더에서 사용된 ${\alpha}-{\beta}$ 추적필터의 잔차로부터 추적 정확도의 지표인 거리오차와 각도 오차의 표준편차를 도출한 결과이며, 통계적 방법으로 sample variance 개념을 사용하게 된다.

Understanding Students' Choice of Becoming Certified Sharia Accountant in Indonesia

  • KHOLID, Muamar Nur;TUMEWANG, Yunice Karina;SALSABILLA, Selfira
    • The Journal of Asian Finance, Economics and Business
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    • 제7권10호
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    • pp.219-230
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    • 2020
  • With the largest number of Islamic financial institutions across the world, the demand for a qualified Sharia accountant in Indonesia is indeed inevitable. This study aims to examine the determinant factors of the intention for accounting students to become Certified Sharia Accountant. This study used quantitative method with primary data through questionnaire from 248 selected samples. The data is then analyzed by Partial Least Square Structural Equation Model. This research has used Theory of Planned Behavior combined with Islamic religiosity to explain 67.80% of the intention of accounting students to become Certified Sharia accountants. The test results indicate perceptions of greater job opportunities, good ethical reputation, Islamic religiosity, technical skills, and subjective norm that affects the intention to become Certified Sharia Accountants. The findings of this study contribute to the literature regarding career selection in the field of accounting in general and Certified Sharia Accountants in particular. The results of this study also have a practical impact on the academic world, including the recommendation for curriculum revision and redesign of the learning system. It also has a practical impact on the management of Islamic financial institutions to present them as a promising industry for accounting graduates to work in.

트리즈를 활용한 소프트웨어 개발에 관한 연구 (A Study of Applying TRIZ in Software Development)

  • 김은경;구본철
    • 한국정보통신학회논문지
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    • 제18권3호
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    • pp.719-726
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    • 2014
  • 창의적 문제해결 이론인 트리즈는 기계나 전기, 전자 등과 같은 전통적인 공학 분야에서 널리 활용되어 좋은 성과를 거두고 있으나, 아직 소프트웨어 분야에 적용된 사례는 많지 않다. 하지만 소프트웨어도 다른 어떤 분야 못지않게 창의적 문제해결 역량이 요구되는 분야이므로, 트리즈를 활용한다면 놀랄 만한 성과를 얻을 수 있을 것으로 예상된다. 따라서 본 논문에서는 트리즈를 적용해서 스마트 클리커라는 새로운 소프트웨어를 개발해 봄으로써 소프트웨어 분야에서는 트리즈를 활용하기 어렵다는 심리적 타성을 타파하고, 소프트웨어 분야에서 트리즈를 활용하는 접근방법을 제시하였다.

유도전동기의 자기등가회로 해석을 위한 시스템 매트릭스 구성 (Formation of System Matrix for analyzing Magnetic Equivalent Circuit of Induction Motor)

  • 최재영;이은웅;정종호;김성종;우성봉
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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    • pp.330-332
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    • 2000
  • To analyze the transient state of an induction motor, there have been studies for using the magnetic equivalent circuit method(MECD) instead of the time differential finite-element method. MECD which analyzes magnetic equivalent circuits after converting each part of an electric machine into the magnetic circuit elements, has the merits of short calculation-time and comparatively accurate results. To analyze an electric machine with MECM, we have to replace stator and rotor with the magnetic elements and express the air gap, where electromechanical energy conversion takes place, with the permeance. So in this study, to analyze an Induction Motor with HECM, we express the magnetic equivalent circuit as algebraic equations and then as the matrix for solving easily them. In particular, all relations are formed with matrixes to solve Mathematically them in the programming process later. As a result, this theory will be the basis on the static and dynamic analysis of an Induction Motor.

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U-Learning을 위한 위치 기반 서비스로서의 상황 인식 기술 (Context-Awareness Technology for Location Based-Service for Ubiquitous Learning)

  • 김혜진
    • 한국산학기술학회논문지
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    • 제12권11호
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    • pp.4869-4874
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    • 2011
  • 본 논문에서는 위치 기반 서비스로서의 U-Learning에 적용할 수 있는 구성 및 온톨리지 이론을 정의하였다. 또한 본 논문에서는 위치 기반 서비스로서의 U-Learning에 대한 확실한 비전을 제공하고자 하였다. 상황 인식을 적용한 전형적인 U-Learning을 소개하였으며, 핵심 아이디어 및 기술적 개념을 포함한 학습 환경 구조도 소개하였다. 고급 정보통신 기술의 원리를 적용하여, 위치 기반 서비스로서의 U-Learning을 위한 인공지능 기반 상황 인식 개념도 정리하였다. 본 논문에서 언급하는 위치 기반 서스비로서의 U-Learning 및 하위 개념들은 새로운 패러다임을 제공할 것이며, 학습 환경 구조에 포함된 하위 요소들도 모두 제안하였다.

Distance Learning In Ukraine: Problems And Connection With Modern Computer Technologies

  • Skoromnyi, Viktor;Voichenko, Olha;Ostapenko, Liliya;Trynko, Olga;Shportko, Oleksii;Tishkina, Olena
    • International Journal of Computer Science & Network Security
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    • 제21권8호
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    • pp.105-110
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    • 2021
  • The article presents the idea that in the conditions of modernization of higher professional education, there is an obvious contradiction between the practical need of higher education for a scientifically grounded theory and methodology of distance learning for students and the lack of the necessary didactic and content-methodological guidelines for its implementation. In theoretical research and applied development, as a rule, the technocratic approach prevails. The emphasis is on the technical capabilities of modern computers and telecommunications. Productively, from a pedagogical point of view, this contradiction can be resolved on the basis of modeling distance learning management for students, developing and implementing a corporate information educational environment in universities, increasing the effectiveness of the methodology of pedagogical interaction between students and teachers during the implementation of distance learning.