• 제목/요약/키워드: Alignment-based design

검색결과 189건 처리시간 0.032초

기구학적 커플링으로 구성된 3자유도 병렬 메커니즘 해석 및 설계 (Analysis and Design of 3-DOF Parallel Mechanism Based on Kinematic Couplings)

  • 왕위준;한창수
    • 한국생산제조학회지
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    • 제21권3호
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    • pp.479-486
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    • 2012
  • This paper presents a high-speed automatic micro-alignment system that is a part of an inspection machine for small-sized molded lenses of mobile phones, palm-top computers, and so on. This work was motivated by the shortcomings of existing highest-grade commercial machine. A simple tip/tilt/Z parallel mechanism is designed based on kinematic couplings, which is a 3-degree-of-freedom (3-DOF) moderate-cost alignment stage. It is used to automatically adjust the posture of each lens on the tray, which is impossible by the conventional instrument. Amplified piezoelectric actuators are used to ensure the accuracy and dynamic response. Forward kinematic analysis and simulation show that the parasitic motion is small enough compared to the actuator stroke. From the workspace analysis of the moving platform, it is clear that the output motion range satisfies the design requirements.

Design standard for fairway in next generation

  • Ohtsu, Kohei;Yoshimura, Yasuo;Hirano, Masayoshi;Takahashi, Hironao;Tsugane, Masanori;Ohtsu, Kohei
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 Asia Navigation Conference
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    • pp.230-239
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    • 2006
  • The depth, width and alignment of fairway that are main port water facilities should be designed considering the various elements including particulars of design ships, weather and sea conditions around fairway and method of ship-handling. However not only the existing Japanese design standard for fairway and also those of other countries do not take into consideration of such kind of elements and no design standard is made by quantitative analysis. In this circumstance the new design standard (Approach Channels, A Guide for Design) depending on classified various elements and quantitative analysis was proposed in 1997 by PIANC and IAPH. But it was proved that calculated values according to this standard were unfounded and had some problems to output the discontinuous value by small difference of calculation condition because the each value fur each element was simply added. And also it is hard to apply this standard to the design of port water facilities in Japan because this [A Guide for Design] is the design standard for long channels in European port. The proposal of more reasonable Japanese standard will be expected by applying the study result of naval architecture and navigation and by the cooperation of ship operators to use fairway, naval architects to built ships and civil engineers to dredge fairway. The concept of a fairway in 'Design standard fur fairway in next generation' is defined as passage for approach channel) and traffic lane designated by light buoys as navigable water for safe navigation. In 'Design standard for fairway in next generation' depth, width and alignment are picked up among many design elements of a fairway. Design method for those elements is shown based on design ships and navigational environments. This standard shows the method of design for each dimension depending on characteristic on design ship and weather and sea condition. On the other hand, in case of existing fairway, it is possible to decide the size of ship and navigation criteria by opposite analysis.

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PHYSICAL PROPERTIES OF FRESH RED PEPPER

  • W. J. La;D. B. Song;Lee, S. K.;Lee, T. K.
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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    • pp.578-585
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    • 2000
  • Geometrical characteristics of fresh red pepper(Capsicum annuum L.) were measured and indexed to define some important geometrical characteristics, and malformation of body and fruit stalk which are necessary for the design of the equipments for cutting, spreading and alignment of red pepper in developing a fruit stalk remover of fresh red pepper. The effects of bending of body and fruit stalk on the equipments of cutting, spreading and alignment were studied. The maximum lengths of some parts of fresh red pepper were found to be 180 mm, 125 mm, 144 mm, 67 mm and 76 mm for the body, the bent part of body, the fruit stalk, the bent part and the straight part of fruit stalk, respectively. The fresh red pepper with bending indices more than 0.4 and 0.3 for the body and the fruit stalk, respectively, was defined to be malformed based on the result of cutting rate using cutting unit; while the other ones to be normal in shape. Based on this, among the total fresh red peppers tested, 47%, 40% and 20% were found malformed for the body, the fruit stalk, and for both of the body and the fruit stalk. Malformed red peppers were poorer in spreading and alignment than normal ones, and the processed quantity was decreased with increased feed rate. The required time for the malformed peppers to pass on the alignment plate inclined at 30 increased rapidly at 8.3 Hz with increased feed rate. For the fresh red peppers with average moisture content of 85%,w.b., the maximum tensile strength between fruit stalk and body was 88.1 N; the maximum cutting resistances were 92.1 N and 94.9 N for the fruit stalk-calyx joint and body, respectively. Average coefficients of static friction were 0.99, 0.62, 0.59 and OJ, respectively, for the surfaces of rubber, galvanized iron, acryl and plywood.

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두 셀 다중 안테나 하향링크 간섭 채널에서 비강인한/강인한 정칙화된 제로포싱 간섭 정렬 방법 (Non-Robust and Robust Regularized Zero-Forcing Interference Alignment Methods for Two-Cell MIMO Interfering Broadcast)

  • 신준우
    • 한국통신학회논문지
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    • 제38A권7호
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    • pp.560-570
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    • 2013
  • 본 논문에서는 셀 간 간섭과 셀 내 사용자 간 간섭이 공존하는 two-cell 다중 안테나 하향링크 간섭 채널에서 송수신기 설계 방법을 제안한다. 우선 셀 간 간섭과 셀 내 사용자 간 간섭을 다차원 subspace에 정렬하는 zero-forcing 간섭 정렬 방법을 일반화한다. 그리고 일반화한 zero-forcing 간섭 정렬 방법에서 구한 송수신기를 "regularizing" 하는 minimum weighted-mean-square-error 기반 regularized ZF-IA 방법을 제안한다. 기존 weighted-sum-rate-maximizing 송수신기 설계 방법에 비해 제안하는 방법은 weight 를 구하는 반복 연산 과정이 필요하지 않다. 그 결과 제안하는 방법은 비록 sum-rate 최대화하도록 설계되진 않았지만, 기존의 weighted-sum-rate maximizing 방법 보다 계산 복잡도 면에서 효율적이고 더 빠른 수렴 속도를 얻을 수 있다. 다양한 분석과 실험을 통해 제안하는 regularized ZF-IA 방법의 우수성을 확인하였다. 구체적으로 반복 연산 수가 작은 경우, 제안하는 regularized ZF-IA 방법의 sum-rate 성능이 기존의 weighted-sum-rate maximizing 방법보다 SNR = 20 [dB] 에서 약 49.8 % 이상 나음을 확인할 수 있다. 더불어 채널 정보에 오차가 있는 경우 상당한 robustness를 제공하는 robust 송수신기 설계 방법도 제시한다.

A Novel Two-Stage Training Method for Unbiased Scene Graph Generation via Distribution Alignment

  • Dongdong Jia;Meili Zhou;Wei WEI;Dong Wang;Zongwen Bai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권12호
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    • pp.3383-3397
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    • 2023
  • Scene graphs serve as semantic abstractions of images and play a crucial role in enhancing visual comprehension and reasoning. However, the performance of Scene Graph Generation is often compromised when working with biased data in real-world situations. While many existing systems focus on a single stage of learning for both feature extraction and classification, some employ Class-Balancing strategies, such as Re-weighting, Data Resampling, and Transfer Learning from head to tail. In this paper, we propose a novel approach that decouples the feature extraction and classification phases of the scene graph generation process. For feature extraction, we leverage a transformer-based architecture and design an adaptive calibration function specifically for predicate classification. This function enables us to dynamically adjust the classification scores for each predicate category. Additionally, we introduce a Distribution Alignment technique that effectively balances the class distribution after the feature extraction phase reaches a stable state, thereby facilitating the retraining of the classification head. Importantly, our Distribution Alignment strategy is model-independent and does not require additional supervision, making it applicable to a wide range of SGG models. Using the scene graph diagnostic toolkit on Visual Genome and several popular models, we achieved significant improvements over the previous state-of-the-art methods with our model. Compared to the TDE model, our model improved mR@100 by 70.5% for PredCls, by 84.0% for SGCls, and by 97.6% for SGDet tasks.

3차원 가속도를 고려한 도로곡선부 유형별 설계기준 제시 (Development of Standard of Highway Curve Geometric Considering 3-D Acceleration)

  • 박정하;박제진;박태훈;하태준
    • 한국도로학회논문집
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    • 제10권4호
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    • pp.247-255
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    • 2008
  • 현행 도로설계의 기준이 되는 "도로의 구조 시설 기준에 관한 규칙 해설 및 지침"에서는 설계속도에 따라 도로 선형별 최소 설계기준을 정하고 있으며, 이 기준을 만족시키면 교통안전성 이 확보되는 것으로 규정하고 있다. 이러한 설계기준에 적용되고 있는 개별 설계요소들은 원칙적으로 차량 및 운전자 특성을 감안하여 설치기준이 정립되었으나, 설계요소간의 연관성 또는 일관성에 대한 깊이 있는 연구를 통해 제반 기준이 정립된 것은 아니다. 결과적으로, 현재의 도로설계기준이 개별 설계 요소들의 조합에 의해 결정되는 도로의 안전성, 일관성 문제를 모두 고려하지는 못하였다. 따라서, 본 연구에서는 기존의 설계기준에 내재된 문제점을 인지하고 해결을 위해 우선적으로 3차원 가속도를 고려한 선형 설계방안에 대한 연구를 수행하였으며, 이를 통해 더욱 안전하고 조화로운 도로건설을 유도하고자 한다.

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슬릿 패턴 형상에 따른 Carbon/Epoxy 프리프레그 성형물의 굽힘 강도 특성 및 슬릿 변형량 분석 (A study on slit opening and flexural strength of carbon/epoxy prepregs with slit patterns)

  • 이성균;원시태;윤길상;김용대;김동언
    • Design & Manufacturing
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    • 제10권2호
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    • pp.6-11
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    • 2016
  • Designed patterns of slit are introduced to the uni-directional (UD) prepreg in order to enhance the formability of the carbon/epoxy composites without wrinkling and laddering. Three different types of the slit alignment along the thickness direction are applied to analyse the deformation behavior during the compression moulding process of laminates. Degrees of the slit open and the mechanical strength are evaluated based on the level of the compaction pressure in the course of forming process. Results have shown that the mechanical strength of laminates having slits could attain at least 80% of the conventional ones without slits. However, further studies are required to identify the direct relevance of the slit alignment in laminate to the mechanical properties.

센서화된 초탄성 마이크로그리퍼의 설계, 제작 및 성능평가 (Design, Fabrication, and Performance Evaluation of a Sensorized Superelastic Alloy Microrobot Gripper)

  • 김덕호;김병규;강현재;김상민
    • 대한기계학회논문집A
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    • 제27권10호
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    • pp.1772-1777
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    • 2003
  • This paper presents the design, fabrication, and calibration of a piezoelectric polymer-based sensorized microgripper. Electro discharge machining technology is employed to fabricate super-elastic alloy based micro gripper. It is tested to present improvement of mechanical performance. For integration of force sensor on the micro gripper, the sensor design based on the piezoelectric polymer PVDF film and fabrication process are presented. The calibration and performance test of force sensor integrated micro gripper are experimentally carried out. The force sensor integrated micro gripper is applied to perform fme alignment tasks of micro opto-electrical components. It successfully supplies force feedback to the operator through the haptic device and plays a main role in preventing damage of assembly parts by adjusting the teaching command.

전주 위치 설계 지원 프로그램 개발 (I) - 유기적 3차원 설계 기법을 중심으로 - (Development of a Pegging Plan Program (I))

  • 이기원;조용현;권삼영;이태권
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1991-1996
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    • 2011
  • The detail design of overhead line can be dievided into a pegging plan and MD(Mounting Diagram) process. A program can perform a MD process was already developed and used in Honam High-Speed project. In this study, a pegging plan program which can perform mast distribution automatically is developed. The system is developed based on dot net framework 4.0 and Civil3D 2012 and used spread 4.0 component for grid UI. It can not be directly used a rail horizontal alignment and long-section profile together on drawing. Therefore using Civil3D, mathematical alignment and profile of rail can be accomplished. And this program has an advantage of user friendly operation because of close relationship between the two.

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평판도파로 브래그격자 제조 및 접속 (Fabrication and Packaging of Planar Waveguide Brags Grating)

  • 한준모;최준석;문형명;임기건;이형종;최두선
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.141-144
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    • 2002
  • Computer code was developed to design waveguide gratings based on coupled-mode equations and the transfer matrix formalism. The experimental set-up has been constructed for inscribing Bragg gratings in planar waveguides with a phase mask and uv laser beam, which enables alignment and packaging of grating devices as well as in-situ performance measurements. Bragg grating has been fabricated on silica planar waveguides with 0.75% Germanium concentration and its transmittance spectrum was measured to have 95% reflectance at the peak wavelength. Optical losses as the function of the misalignment were measured and their usage is described.

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