• 제목/요약/키워드: Technical System Theory

검색결과 246건 처리시간 0.026초

데이터 활용률 제고를 위한 기술 용어의 상호 네트워크 생성과 통제 (Generating and Controlling an Interlinking Network of Technical Terms to Enhance Data Utilization)

  • 정도헌
    • 정보관리학회지
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    • 제35권1호
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    • pp.157-182
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    • 2018
  • 빅 데이터 시대에 접어들면서 저장 기술과 처리 기술이 급속도로 발전함에 따라, 과거에는 간과되었던 롱테일(long tail) 데이터가 많은 기업과 연구자들에게 관심의 대상이 되고 있다. 본 연구는 롱테일 법칙의 영역에 존재하는 데이터의 활용률을 높이기 위해 텍스트 마이닝 기반의 기술 용어 네트워크 생성 및 통제 기법을 제안한다. 특히 텍스트 마이닝의 편집 거리(edit distance) 기법을 이용해 학문분야에서 사용되는 기술 용어의 상호 네트워크를 자동으로 생성하는 효과적인 방안을 제시하였다. 데이터의 활용률 향상 실험을 위한 데이터 수집을 위해 LOD(linked open data) 환경을 이용하였으며, 이 과정에서 효과적으로 LOD 시스템의 데이터를 활용하는 기법과 용어의 패턴 처리 알고리즘을 제안하였다. 마지막으로, 생성된 기술 용어 네트워크의 성능 측정을 통해 제안한 기법이 롱테일 데이터의 활용률 제고에 효과적이었음을 확인하였다.

Nonlinear oscillations of a composite microbeam reinforced with carbon nanotube based on the modified couple stress theory

  • M., Alimoradzadeh;S.D., Akbas
    • Coupled systems mechanics
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    • 제11권6호
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    • pp.485-504
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    • 2022
  • This paper presents nonlinear oscillations of a carbon nanotube reinforced composite beam subjected to lateral harmonic load with damping effect based on the modified couple stress theory. As reinforcing phase, three different types of single walled carbon nanotubes distribution are considered through the thickness in polymeric matrix. The non-linear strain-displacement relationship is considered in the von Kármán nonlinearity. The governing nonlinear dynamic equation is derived with using of Hamilton's principle.The Galerkin's decomposition technique is utilized to discretize the governing nonlinear partial differential equation to nonlinear ordinary differential equation and then is solved by using of multiple time scale method. The frequency response equation and the forced vibration response of the system are obtained. Effects of patterns of reinforcement, volume fraction, excitation force and the length scale parameter on the nonlinear responses of the carbon nanotube reinforced composite beam are investigated.

우리 나라의 농업정보시스템설립을 위한 일연구 (A study for agricultural information system in Korea)

  • 유소영
    • 한국문헌정보학회지
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    • 제12권
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    • pp.225-267
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    • 1985
  • This study is aimed to assure that the agricultural technical information which is the important factor to increase rural production should be widely used by rural communities, and for the wide circulation for the technical information, the appropriate information system is available for the farmers and extention workers who are responsible for the information transfer to farmers. The study is also aimed to find out an outline of a structure and characteristic of the appropriate information system for the rural communities in Korea. The method used to accomplish the purpose of the study, the modernization theory of agriculture of T. W. Schultz was examined and assertions of the information specialists regarding the issues of information transfer and agricultural information system :in developing countries were analyzed. Through the above literary research, the author tried to create the most suitable characteristic and structure of agricultural information system in rural communities in Korea. To justify the author's assertion, a survey through questionniares for a typical rural province was attempted. The assertion that the author tried to convey as the most suitable agricultural information system of this country is the establishment agricultural information analysis center mainly for the extention workers and designing information system which has affiliation between the rural guidance office which is already situated every unit of administractive districts all over the country and public library which is now not properly located and functioned.

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라이브 커머스의 특성이 소비자의 애착 형성과 행동 의도에 미치는 영향 - 사회-기술 시스템론적 관점을 중심으로 - (The Effects of Characteristics of Live Commerce on Consumer Attachment Formation and Behavior Intention - A Socio-technical Systems Perspective -)

  • 차예린;김혜정;박민정
    • 한국의류산업학회지
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    • 제24권3호
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    • pp.303-314
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    • 2022
  • This study examined the impact of the social features (identification, interaction, information value) and technical features (visibility affordance, metavoicing affordance, social connecting affordance) in live commerce on consumers' attachment, which in turn affects consumers' continued intent to watch live commerce and intent to purchase from the platform. Consumers' attachment was represented by emotional attachment to the live shopping streamer and functional dependence on live commerce. Furthermore, this study investigated the effect of attachment on continuous watching intention and purchase intention. Using a web-based survey and consumers in their 20s and 30s (average age: 30.32) as a sample, this study collected 274 usable responses. The results showed that among the live commerce social system constructs, identification and interaction positively affected emotional attachment to the live commerce streamer. Among the live commerce technical system constructs, visibility affordance and social connecting affordance positively influenced functional dependence on live commerce. Both emotional attachment to the live streamer and functional dependence on live commerce were positively related to a continued intent to watch, which influenced the intent to purchase. This study empirically investigated live commerce based on the socio-technical systems framework and confirmed that both social and technical factors have a significant effect on consumers. This study also identified the impact of live commerce on consumers' attitudes through attachment theory. In addition, it has proved the antecedents and effect of continuous watching of live commerce on purchase behavior by focusing on continuous watching intention where less attention was paid in live commerce research.

탄성 변형 영역을 고려한 비정상 평면 변형 이상 공정 이론 (Nonsteady Plane-strain ideal forming with elastic dead zone)

  • 이원오;정관수
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 춘계학술대회 논문집
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    • pp.190-193
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    • 2004
  • Ever since the ideal forming theory has been developed fur process design purposes, application has been limited to sheet forming and, for bulk forming, to two-dimensional steady flow. Here, application for the non-steady case was performed under the plane-strain condition based on the theory previously developed. In the ideal flow, material elements deform following the minimum plastic work path (or mostly proportional true strain path) so that the ideal plane-strain flow can be effectively described using the two-dimensional orthogonal convective coordinate system. Besides kinematics, for a prescribed final part shape, schemes to optimize a preform shape out of a class of initial configurations and also to define the evolution of shapes and boundary tractions were developed. Discussions include the two problematic issues on internal tractions and the non-monotonous straining. For demonstration purposes, numerical calculations were made for a bulk part under forging.

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Structural and Molecular Orbital Properties of Some Boroxine Derivatives-A Theoretical Study

  • Turker, Lemi;Gumus, Selcuk;Atalar, Tane
    • Bulletin of the Korean Chemical Society
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    • 제30권10호
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    • pp.2233-2239
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    • 2009
  • In the present study, firstly, the variations of the geometric parameters induced by different substituents on boroxine skeleton (symmetrically H, $CH_3$, Cl, F, $NO_2$ substituted boroxines) are investigated by using B3LYP/6-31G(d,p), RHF/6-31G(d,p), and MP2/6-31G(d,p) levels of the theory. The second objective is to estimate the substituent effect on the molecular aromaticity of boroxine derivatives using energetic and NICS criteria. Moreover, the effects of different theoretical levels on NICS values have been investigated in a systematic approach. Lastly, a rotational analysis has been performed to investigate the effect of rotation around the B-Me and B-$NO_2$ bonds on total energy of the system. It has been found that electron withdrawing substituents contribute the aromaticity of boroxine affirmatively. Conversely, electron donors make the system less aromatic. Also, the theoretical vibrational spectra for these boroxine derivatives are presented and compared with the experimental data from the literature.

고트프리트 젬퍼(Gottfried Semper)와 칼 뵈티허 (Karl B$\ddot{o}$tticher)의 텍토닉 개념 비교 (A Comparative Study on the Theory of Tectonics between Gottfried Semper and Karl B$\ddot{o}$tticher)

  • 정인하
    • 건축역사연구
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    • 제7권4호
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    • pp.77-91
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    • 1998
  • The theory of tectonic appeared in the midst of 19th century as German architects adopted new materials and structural technology, invented by creative engineers, into architectural design. This does not merely mean a technical problem but concern the redefinition of architecture in term of an aesthetic, cultural, and ontological identity. Furthermore it alluded to a desire on the part of architectural theorists to actualize artistic and spiritual goals out of new constructional necessities. Because of their complex discourse that assumed the possibility of communication between philosophical and technical aspects, between ideal and real concerns, tectonics becomes until now the most important issue in architecture. The concept of tectonic was intensively investigated by Gottfried Semper's and Karl B$\ddot{o}$tticher architectural writings. They contributed to clarify the principle aspects of tectonic within architectural, philosophical, and anthropological discourses of 19th century. Gottfried Semper stressed an understanding of how architecture took on physical form in earliest human culture. He placed great importance on the artistic expression of materials. But unlike Semper who argued the cladding of the structural frame by decorative wall system, Karl Botticher required maximum visibility of structural frame. This represents the different positions between Gottfried Semper and Karl Botticher

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Sliding mode control for structures based on the frequency content of the earthquake loading

  • Pnevmatikos, Nikos G.;Gantes, Charis J.
    • Smart Structures and Systems
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    • 제5권3호
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    • pp.209-221
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    • 2009
  • A control algorithm for seismic protection of building structures based on the theory of variable structural control or sliding mode control is presented. The paper focus in the design of sliding surface. A method for determining the sliding surface by pole assignment algorithm where the poles of the system in the sliding surface are obtained on-line, based on the frequency content of the incoming earthquake signal applied to the structure, is proposed. The proposed algorithm consists of the following steps: (i) On-line FFT process is applied to the incoming part of the signal and its frequency content is recognized. (ii) A transformation of the frequency content to the complex plane is performed and the desired location of poles of the controlled structure on the sliding surface is estimated. (iii) Based on the estimated poles the sliding surface is obtained. (iv) Then, the control force which will drive the response trajectory into the estimated sliding surface and force it to stay there all the subsequent time is obtained using Lyapunov stability theory. The above steps are repeated continuously for the entire duration of the incoming earthquake. The potential applications and the effectiveness of the improved control algorithm are demonstrated by numerical examples. The simulation results indicate that the response of a structure is reduced significantly compared to the response of the uncontrolled structure, while the required control demand is achievable.

퍼지추론을 이용한 설비가동상태진단 모델 연구 (Development of Equipment Operating Condition Diagnosis Model Using the Fuzzy Inference)

  • 정영득;박주식
    • 산업경영시스템학회지
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    • 제28권4호
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    • pp.109-115
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    • 2005
  • In the study, Methods for operating measures in equipment security to find out dangerousness timely in the system and to need for the prevention and measures. The method for analyzing and reconstructing the causes of accident of equipment in site, and try to save the information of site in real-time and to analyze the state of equipment to look for the factors of accidents. By this analysis, one plan for efficiency of production, Equipment Fault Diagnosis Management and security is integrating and building module of using the Fuzzy Inference based on fuzzy theory. The case study is applied to the industrial electric motors that are necessarily used to all manufacturing equipment. Using the sensor for temperature is attached to gain the site information in real time and to design the hardware module for signal processing. In software, realize the system supervising and automatically saving to management data base by the algorithm based in fuzzy theory from the existing manual input system

Transient thermoelastic analysis of carbon/carbon composite multidisc brake using finite element method

  • Ghashochi-Bargh, Hadi;Goodarzi, Mohammad-Saeed;Karimi, Masoud;Salamat-Talab, Mazaher
    • Advances in aircraft and spacecraft science
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    • 제7권2호
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    • pp.135-149
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    • 2020
  • In the current paper, a generalization of the results of Zhao et al. (2008) on a new design of C/C composite multidisc brake system is presented. The purpose of this paper is to study the effect of thermal sensitivity of Carbon/Carbon (C/C) composite material on the temperature distributions, deformation, and stress during braking. In this regard, a transient temperature-displacement coupled analysis for C/C composite brake discs with frictional heat generation under simulated operating conditions is performed. An axisymmetric model for brake system is used for the finite element analysis according to the theory of energy transformation and transportation. The transient temperature distributions on the friction surfaces, deformation, and stress are obtained. To check the validity, the results are corroborated with other solutions available in the literature, wherever possible. The current study could be used as a guide in the initial design of a high performance multidisc brake system.