• 제목/요약/키워드: requirement engineering

검색결과 3,024건 처리시간 0.038초

간결하고 효율적인 폴리곤 메쉬의 표현 구조 (A Compact and Efficient Polygonal Mesh Representation)

  • 박상근;이상헌
    • 한국CDE학회논문집
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    • 제9권4호
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    • pp.294-305
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    • 2004
  • Highly detailed geometric models are rapidly becoming commonplace in computer graphics and other applications. These complex models, which is often represented as complex1 triangle meshes, mainly suffer from the vast memory requirement for real-time manipulation of arbitrary geometric shapes without loss of data. Various techniques have been devised to challenge these problems in views of geometric processing, not a representation scheme. This paper proposes the new mesh structure for the compact representation and the efficient handling of the highly complex models. To verify the compactness and the efficiency, the memory requirement of our representation is first investigated and compared with other existing representations. And then we analyze the time complexity of our data structure by the most critical operation, that is, the enumeration of the so-called one-ring neighborhood of a vertex. Finally, we evaluate some elementary modeling functions such as mesh smoothing, simplification, and subdivision, which is to demonstrate the effectiveness and robustness of our mesh structure in the context of the geometric modeling and processing.

Ethernet Ring Protection Using Filtering Database Flip Scheme For Minimum Capacity Requirement

  • Rhee, June-Koo Kevin;Im, Jin-Sung;Ryoo, Jeong-Dong
    • ETRI Journal
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    • 제30권6호
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    • pp.874-876
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    • 2008
  • Ethernet ring protection is a new technology introduced in ITU-T Recommendation G.8032, which utilizes the generic Ethernet MAC functions. We introduce an alternative enhanced protection switching scheme to suppress penalty in the switching transient, in which the Ethernet MAC filtering database (FDB) is actively and directly modified by information disseminated from the nodes adjacent to failure. The modified FDB at all nodes are guaranteed to be consistent to form a complete new ring network topology immediately. This scheme can reduce the capacity requirement of the G.8032 by several times. This proposed scheme can be also applied in IP protection rings.

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공리적설계를 이용한 휴대폰 슬라이드 기구의 스파이럴 스프링 설계 (Design of Spiral Spring in Sliding Mechanism for Mobile Phones Using Axiomatic Design)

  • 황은하;한덕희
    • 한국산업융합학회 논문집
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    • 제10권3호
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    • pp.171-177
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    • 2007
  • It is well known that mobile phones have been a indispensable communication tool for human life. The spiral springs are used as the main component of the semi-auto sliding mechanism of mobile phones. The characteristic of axiomatic approach is scientific and analytical method, and axiomatic approach is different from other design methods in offering the systematic method at an early stage of design. The axiomatic approach could determine design parameter and arrange the order of design and estimate the optimum design in good order. In axiomatic approach, the composition is divided by customer requirement, functional requirement, design parameter, and design matrix in large portion. This paper presents design in sliding mechanism for mobile phones by finite element method and axiomatic design.

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저궤도 지구관측위성의 광학탑재체 지지구조물 설계 연구 (A Study on the Optical Bench for LEO Earth Observation Satellite)

  • 김경원;김진희;이주훈;진익민;김종우
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.805-808
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    • 2005
  • This paper is a study on an optical bench satisfying stiffness and thermal pointing error requirements for LEO earth observation satellite. According to shape and stiffness requirements, optical bench type 1 is designed. Because type 1 does not satisfy the thermal pointing error requirement, an optical bench type 2 is suggested. Although the type 2 has better results than type 1, it still does not meet the thermal pointing error requirement. Using the results of optical bench type 1&2, the optical bench type 3 is finally designed, which satisfies both the stiffness and thermal pointing error requirements.

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신경회로망과 퍼지필터를 사용한 근전도신호의 기능변별에 관한 연구 (A Study on Function Discrimination for EMG Signals Using Neural Network and Fuzzy Filter)

  • 장영건;홍승홍
    • 대한의용생체공학회:의공학회지
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    • 제15권3호
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    • pp.355-364
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    • 1994
  • The most important requirement for the controller of a prosthetic arm is that it has a high fidelity discriminator where the motion control may be performed open loop using EMG signals as a control source. Therefore, it is very effective method to reduce the influence of misclassification of classifier for the total system performance. This paper presents the new function discrimination method which combines MLP classifier and frizzy filter by stages for the requirement. The major advantage of MLP is a consistent learning capability for the easy adaptation to environments. The fuzzy filter uses all informations of MLP outputs and prior EMG activity informations which increase as the experience increases. That property is superior to one which uses maximum output of MLP in view of information amounts and quality. Simulation result shows that proposed method is superior to the probabilistic model, MLP model and the combined model of both in the respect of discrimination quaity.

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운용가용도 제약하에서의 소모성 동시조달부품의 최적구매량 결정 (Optimal Provisioning Quantity Determination of Consumable Concurrent Spare Part under the Availability Limitation)

  • 오근태;김명수
    • 산업경영시스템학회지
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    • 제21권48호
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    • pp.113-122
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    • 1998
  • In this paper we consider the CSP requirements determination problem of new equipment(machine) system. For the newly procured equipment systems, mathematical analyses are made for the system which is constructed with the consumable parts to derive the associated CSP requirement determination model in mathematical expression. Based on these analyses, a mathematical model is derived for making an optimal CSP requirement determination subject to tile constraint of satisfying any given operational availability limitation. We assume that the failure of a part follows a Poisson process. Firstly, the operational availability concept in CSP is defined and the relation between the general system availability and the operational availability is established. Secondly, the problem is formulated as the cost minimization problem that should satisfy the operational availability limitation, and then, using the generalized Lagrange multipliers method, the optimal solution procedure is derived.

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싸이리스터 컨버터부하를 가지는 병렬형 능동전력필터 용량에 관한 연구 (A Study on the capacity of shunt type active power filter with a thyristor converter load)

  • 박노중;정숭기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 F
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    • pp.2470-2474
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    • 1999
  • The main drawback of parallel type active power filters (APFs) is the large capacity required for harmonic compensation. This paper evaluates the APF capacity requirement for harmonic/reactive power compensation for thyristor converter load. Theoretically achievable maximum power factor under partial load is evaluated. it is shown that the APF capacity can be considerably reduced by deliberately limiting the peak current, while maintaining the filtering performance with an acceptable total harmonic current level. the minimum capacity requirement of APF with current limiting is evaluated as a function of the firing angle of thyristor converter and short circuit ratio(SCR).

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공리적 접근을 통한 CD-ROM 드라이브의 소음 진동저감 설계평가 (Axiomatic Approach for the Design of Reducing the Noise and Vibration of CD-ROM Drive)

  • 이재승;차성운
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.504-509
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    • 2001
  • CD-ROM drive is improved in rotation speed up to 10,000 rpm. But Vibration and Noise are also increased simultaneously more and more. So many attempts are tried to reduce the unexpected effects. Most attempts are not enough to cover the increasement of Noise and Vibration. Merely availed tries are accumulated in many part and it makes the structure complicated. The Axiomatic approach could arrange the order of design and estimate the optimum design in good oder. In Axiomatic Approach, the composition is divided by Customer Requirement, Functional Requirement, Design Parameter and Design Matrix in large portion. This method also could show more effective way to design before making a prototype.

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Five-axis finishing tool path generation for a mesh blade based on linear morphing cone

  • Zhang, Rong;Hu, Pengcheng;Tang, Kai
    • Journal of Computational Design and Engineering
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    • 제2권4호
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    • pp.268-275
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    • 2015
  • Blisk is an essential component in aero engines. To maintain good aero-dynamic performance, one critical machining requirement for blades on blisk is that the generated five-axis tool path should be boundary-conformed. For a blade discretely modeled as a point cloud or mesh, most existing popular tool path generation methods are unable to meet this requirement. To address this issue, a novel five-axis tool path generation method for a discretized blade on blisk is presented in this paper. An idea called Linear Morphing Cone (LMC) is first proposed, which sets the boundary of the blade as the constraint. Based on this LMC, a CC curve generation and expansion method is then proposed with the specified machining accuracy upheld. Using the proposed tool path generation method, experiments on discretized blades are carried out, whose results show that the generated tool paths are both uniform and boundary-conformed.

파괴메카니즘을 고려한 강박스교량의 내진설계 (Earthquake Resistant Design of Steel Box Bridges considering Failure Mechanism)

  • 국승규;이동휘
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2002년도 추계 학술발표회 논문집
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    • pp.330-337
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    • 2002
  • The objective of the earthquake resistant design of structures is to satisfy on the one side the minimization of damage requirement under earthquakes with high probability of occurrence during the design life and on the other side the no collapse requirement under the design seismic event with low probability of occurrence. The two requirements are satisfied with the minimum strength of substructure as well as the ductile failure mechanism presented in the codes. In this study seismic performance is evaluated with two bridges which have steel box superstructures and T type, II type piers as substructures. In order to satisfy the two requirements redesign of both substructures and steel bearings are carried out.

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