• Title/Summary/Keyword: sub assembly

Search Result 282, Processing Time 0.027 seconds

Compensation of Installation Errors in a Laser Vision System and Dimensional Inspection of Automobile Chassis

  • Barkovski Igor Dunin;Samuel G.L.;Yang Seung-Han
    • Journal of Mechanical Science and Technology
    • /
    • v.20 no.4
    • /
    • pp.437-446
    • /
    • 2006
  • Laser vision inspection systems are becoming popular for automated inspection of manufactured components. The performance of such systems can be enhanced by improving accuracy of the hardware and robustness of the software used in the system. This paper presents a new approach for enhancing the capability of a laser vision system by applying hardware compensation and using efficient analysis software. A 3D geometrical model is developed to study and compensate for possible distortions in installation of gantry robot on which the vision system is mounted. Appropriate compensation is applied to the inspection data obtained from the laser vision system based on the parameters in 3D model. The present laser vision system is used for dimensional inspection of car chassis sub frame and lower arm assembly module. An algorithm based on simplex search techniques is used for analyzing the compensated inspection data. The details of 3D model, parameters used for compensation and the measurement data obtained from the system are presented in this paper. The details of search algorithm used for analyzing the measurement data and the results obtained are also presented in the paper. It is observed from the results that, by applying compensation and using appropriate algorithms for analyzing, the error in evaluation of the inspection data can be significantly minimized, thus reducing the risk of rejecting good parts.

Optimization of Emulsion Polymerization for Submicron-Sized Polymer Colloids towards Tunable Synthetic Opals

  • Kim, Seul-Gi;Seo, Young-Gon;Cho, Young-Jin;Shin, Jin-Sub;Gil, Seung-Chul;Lee, Won-Mok
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.7
    • /
    • pp.1891-1896
    • /
    • 2010
  • Submicron-sized polymeric colloidal particles can self assemble into 3-dimensional (3D) opal structure which is a useful template for photonic crystal. Narrowly dispersed polymer microspheres can be synthesized by emulsion polymerization in water using water-soluble radical initiator. In this report, we demonstrate a facile and reproducible emulsion polymerization method to prepare various polymeric microspheres within 200 - 400 nm size ranges which can be utilized as colloidal photonic crystal template. By controlling the amount of monomer and surfactant, monodisperse polymer colloids of polystyrene (PS) and acrylates with various sizes were successfully prepared without complicated synthetic procedures. Such polymer colloids self-assembled into 3D opal structure exhibiting bright colors by reflection of visible light. The colloidal particles and the resulting opal structures were rigorously characterized, and the wavelength of the structural color from the colloidal crystal was confirmed to have quantitative relationship with the size of constituting colloidal particles as predicted by Bragg equation. The tunability of the structural color was achieved not only by varying the particle size but also by infiltration of the colloidal crystal with liquids having different refractive indices.

Checks, grids and tartans

  • Wang, Chaoran;Hann, Michael Andrew
    • The Research Journal of the Costume Culture
    • /
    • v.23 no.5
    • /
    • pp.922-927
    • /
    • 2015
  • Checks are best considered as a (visible) sub-set of grids, and each check consists of two assemblies of parallel lines, one superimposed on the other at ninety degrees. In the conventional textile context, one assembly of parallel yarns is superimposed on another at ninety degrees. These parallel lines caused by the yarns remain visually apparent in the finished composition. Commonly, checks are considered simply as a variety of woven textile and Scottish clan tartans, or plaids (common terminology for tartans in the USA), famously display a checked feature, using differently colored yarns in woven-textile form. Often the sequence of colours and the numbers of yarns used is equal in both warp and weft directions. Where this is the case, the tartan may be considered to be 'balanced' or 'regular', with the component yarns creating square units repeating across and down the fabric. Thus in balanced tartans, lengthways components have identical ordering, colouring and measured width to those used widthways. Meanwhile an unbalanced check lacks one or more of these attributes. This paper explores further the nature of Scottish clan tartans, using data collected from collections of rare tartans held at ULITA - An Archive of International Textiles at the University of Leeds.

A Study of the Indoor Air Quality Improvement for Large Scale Assembly Facilities (건축물의 대공간 집회시설의 실내공기질 개선방안에 관한 연구)

  • Lim, Tae-Sub;Kang, Seung-Mo
    • Korean Institute of Interior Design Journal
    • /
    • v.20 no.4
    • /
    • pp.183-190
    • /
    • 2011
  • Lately majority of churches have preferred to enlarge their worship area to both horizontal and vertical axis. According to expand their area which brings more devotees to the limited service area. Transform from a small church into a large church is no longer unprecedented issue in South Korea. As the size of church getting bigger, many unexpected issues become matters. One of the significant problem is that the number of people have experienced either fall a sleep or feel a doziness during their service period. Due to the limited condition for the specific building type such as religion facility(church), IAQ improvements is seriously concerned. Therefore, we are going to examine by using simulation tool, CF, a difference of ventilation efficiency about the location and number of windows, and find the best way of the ventilation efficiency in a multi-stories type church by changing the exhaust pipes location and size. Furthermore, in this thesis, by changing a ceiling height from the existing building to confirm that $CO_2$ have been satisfied for both the ventilation efficiency and IAQ.

Anchored blind bolted composite connection to a concrete filled steel tubular column

  • Agheshlui, Hossein;Goldsworthy, Helen;Gad, Emad;Mirza, Olivia
    • Steel and Composite Structures
    • /
    • v.23 no.1
    • /
    • pp.115-130
    • /
    • 2017
  • A new type of moment-resisting bolted connection was developed for use in composite steel- concrete construction to connect composite open section steel beams to concrete filled steel square tubular columns. The connection was made possible using anchored blind bolts along with two through bolts. It was designed to act compositely with the in-situ reinforced concrete slab to achieve an enhanced stiffness and strength. The developed connection was incorporated in the design of a medium rise (five storey) commercial building which was located in low to medium seismicity regions. The lateral load resisting system for the design building consisted of moment resisting frames in two directions. A major full scale test on a sub-assembly of a perimeter moment-resisting frame of the model building was conducted to study the system behaviour incorporating the proposed connection. The behaviour of the proposed connection and its interaction with the floor slab under cyclic loading representing the earthquake events with return periods of 500 years and 2500 years was investigated. The proposed connection was categorized as semi rigid for unbraced frames based on the classification method presented in Eurocode 3. Furthermore, the proposed connection, composite with the floor slab, successfully provided adequate lateral load resistance for the model building.

Dynamic Modeling of a Satellite with Solar Array Flexible Modes (태양전지판의 유연 모드를 고려한 위성의 동적 모델링)

  • Kim, Dae-Kwan;Park, Young-Woong;Park, Keun-Joo;Yang, Koon-Ho;Yong, Ki-Lyuk
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.37 no.9
    • /
    • pp.837-842
    • /
    • 2009
  • The efficient dynamic modeling of a satellite with flexible solar arrays is established by using the component mode synthesis technique. A flexible satellite model can be defined as the assembly of two sub-structures, central body and solar array. The reduced models of each substructure, which are expressed in each local frame, are coupled with respect to the satellite reference frame. The dynamic modeling method is applied to the numerical example of a satellite with a single solar array, and is verified by investigating the transfer function results with considering the solar array rotation.

The AS4059 Hydraulic System Cleanliness Classification System: Replacement of NAS1638

  • Day, Mik;Hong, Jeong-Hee
    • Journal of Drive and Control
    • /
    • v.9 no.2
    • /
    • pp.39-45
    • /
    • 2012
  • The NAS 1638 cleanliness classification system was originally developed in 1966 by the US Aircraft Industries of America to both simplify reporting of particle count data and to control the introduction of dirt during the assembly of aircraft fluid systems. The numbers of particles at stated sizes are represented by broad bands where the interval was generally a doubling of contamination. A number of systems have been introduced since this to suit differing requirements. NAS 1638 and AS4059 are used in other industrial sectors such as the Off-shore & Sub-Sea and the Primary Metal Industries. The changes to ISO contamination measurement standards controlled by ISO/TC131/SC6 in 1999 meant that a revision of most of these classification systems was necessary. The body responsible for NAS 1638 decided to withdraw it for new installations and replace it with an update of an existing standard, SAE AS 4059. This paper details the philosophy behind the contamination coding systems, the reasons for the changes to the ISO contamination standards and explains the workings of AS 4059, the replacement for NAS 1638. It goes on to detail the latest changes to this standard.

An Experimental Study on Brake Judder of Braking on Vehicle (실차 상태에서의 제동시 이상떨림 현상에 관한 실험적 연구)

  • Hong, Il-Min;Lee, Won-Sub;Lee, Jong-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.12 no.5
    • /
    • pp.338-345
    • /
    • 2002
  • The study presents a new testing and analysis method for brake judder on vehicle. For the identification of the excitation mechanism of a brake judder, it is necessary to measure the dynamic brake disc geometry during braking on vehicle. The non-contact sensor system was used to monitor the brake disc geometry. Brake torque variation (BTV) caused by disc thickness variation (DTV) is the primary excitation for brake judder. The mechanical effects generating BTV are linked not only to initial manufacturing tolerances but also to uneven wear. Therefore, the brake disc geometry should be strictly managed to initial condition. The aim of this study has been to measure the dynamic DTV and runout on vehicle and analyze the influence of test parameters on brake judder and compare the disc component with vehicle matching about the DTV Profile. As a result of this study, The amplitude of brake judder is proportional to vehicle speed and fluid pressure fluctuation on braking. The major sources of brake judder are directly related to disc thickness variation and side runout variation of corner assembly (disc, hub. bearing).

Research Trends on Compassion Fatigue in Korea Nurses (간호사의 공감피로에 관한 국내연구동향)

  • Cho, Ho Jin;Jung, Myun Sook
    • Journal of muscle and joint health
    • /
    • v.21 no.3
    • /
    • pp.255-264
    • /
    • 2014
  • Purpose: The purpose of the study were to analyze the research trends of compassion fatigue in Korea nurses and to suggest future research directions. Methods: For this study, RISS, KISTI, KISS, National Assembly Library databases were searched using the key words 'compassion fatigue', 'secondary traumatic stress', 'professional quality of life' that contains compassion fatigue as a sub-element, and 'nurses' for this study. A total of 124 articles published in June 2014 were searched and analyzed 19 articles for the final analysis. Results: The most frequently used study design was descriptive (N=17, 89.5%). High compassion fatigue was reported in this study. Factors affecting compassion fatigue were personal factors (e.g., age, health state, and sleep hours), work-related factors (e.g., experience with traumatized patients), and psychological factors (e.g., job stress, anxiety, excessive empathy, social support, and coping strategy). Finally, Consequence factors of compassion fatigue was reported burnout, silencing response and turnover intention. Conclusion: There was a few studies on compassion fatigue. Further research on compassion fatigue needs to use a variety of study designs instruments suitable for Korean nurses, and to develop management programs on compassion fatigue in nurses.

Concurrent engineering solution for the design of ship and offshore bracket parts and fabrication process

  • Kim, Tae-Won;Lim, Sang-Sub;Seok, Ho-Hyun;Kang, Chung-Gil
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.5 no.3
    • /
    • pp.376-391
    • /
    • 2013
  • Brackets in ships and offshore structures are added structures that can endure stress concentrations. In this study, a concurrent engineering solution was proposed, and a high strength low carbon cast steel alloy applicable to offshore structures was designed and developed. The yield strength and ultimate tensile strength of the designed steel were 480 and 600 MPa, respectively. The carbon equivalent of the steel was 0.446 with a weld crack susceptibility index of 0.219. The optimal structural design of the brackets for offshore structures was evaluated using ANSYS commercial software. The possibility of replacing an assembly of conventional built-up brackets with a single casting bulb bracket was verified. The casting process was simulated using MAGMAsoft commercial software, and a casting fabrication process was designed. For the proposed bulb bracket, it was possible to reduce the size and weight by approximately 30% and 50%, respectively, compared to the conventional type of bracket.