• Title/Summary/Keyword: Alignment-based design

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

  • Wang, Wei-Jun;Han, Chang-Soo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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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
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.10a
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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.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11c
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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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Non-Robust and Robust Regularized Zero-Forcing Interference Alignment Methods for Two-Cell MIMO Interfering Broadcast (두 셀 다중 안테나 하향링크 간섭 채널에서 비강인한/강인한 정칙화된 제로포싱 간섭 정렬 방법)

  • Shin, Joonwoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.7
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    • pp.560-570
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    • 2013
  • In this paper, we propose transceiver design strategies for the two-cell multiple-input multiple-output (MIMO) interfering broadcast channel where inter-cell interference (ICI) exists in addition to inter-user interference (IUI). We first formulate the generalized zero-forcing interference alignment (ZF-IA) method based on the alignment of IUI and ICI in multi-dimensional subspace. We then devise a minimum weighted-mean-square-error (WMSE) method based on "regularizing" the precoders and decoders of the generalized ZF-IA scheme. In contrast to the existing weighted-sum-rate-maximizing transceiver, our method does not require an iterative calculation of the optimal weights. Because of this, the proposed scheme, while not designed specially to maximize the sum-rate, is computationally efficient and achieves a faster convergence compared to the known weighed-sum-rate maximizing scheme. Through analysis and simulation, we show the effectiveness of the proposed regularized ZF-IA scheme.

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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    • v.17 no.12
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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.

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

  • Park, Jung-Ha;Park, Je-Jin;Park, Tae-Hoon;Ha, Tae-Jun
    • International Journal of Highway Engineering
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    • v.10 no.4
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    • pp.247-255
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    • 2008
  • According to "A guide Book to Highway Design", most road elements are chosen based on a certain design speed in order to ensure obtaining safe and smooth traffic operating. However, road safety in practical way is corelative to not only all element of roads but also road shape, for example, between straight line and curves line and between curved lines. Also, it is relates to alignments such as horizontal alignment, vertical alignment, and cross section. That is, the practical road design should be examined in both sides of 3 dimension and consecutiveness as the practical road is a 3-dimensional successive object. The paper presents a concept for acceleration to evaluate consistency of road considering actual road shape on 3-dimension. Acceleration of vehicle is influential to road consistency based on running state of vehicle and state of drivers. Especially, the magnitude of acceleration is a quite influential element to drivers. Based on above, the acceleration on each point 3-D road can be calculated and then displacement can be done. Computation of acceleration means total calculation on each axis.

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

  • Lee, Sung-Gyun;Won, Si-Tae;Yoon, Gil-Sang;Kim, Yong-Dae;Kim, Dong-Earn
    • Design & Manufacturing
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    • v.10 no.2
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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.

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

  • Kim, Deok-Ho;Kim, Byung-Kyu;Kang, Hyun-Jae;Kim, Sang-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.10
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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.

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

  • Lee, Ki-Won;Cho, Yong-Hyeon;Kwon, Sam-Young;Lee, Tae-Kwon
    • Proceedings of the KSR Conference
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    • 2011.10a
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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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Fabrication and Packaging of Planar Waveguide Brags Grating (평판도파로 브래그격자 제조 및 접속)

  • 한준모;최준석;문형명;임기건;이형종;최두선
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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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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