• Title/Summary/Keyword: tolerance analysis

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Producer-Consumer Tolerances Considering Process Mean Deviation (공정평균 편차를 고려한 허용차 결정)

  • 송서일;박영호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.14 no.24
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    • pp.31-41
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    • 1991
  • The producer's to tolerance concept (in contrast to the consumer's tolerence) fellows naturally from the notion of continuous loss function Emerging producer tolerance methodology has proceeded without benefit of carefully defined assumptions. We rectifg this omission and consider the process mean deviation. Then develope the models for which determine the tolerenes in cases of the-nominal-the-best, the-smaller-the-better and the-larger-the-better. Finally the numerical examples are Presented to illustrated these results and also the sensitivity analysis to apprehend the changes of loss tolerances varying with mean is presented.

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The Effect of Airgap Unbalance on the LIM Performance for Light Rail Road (공극 불균형이 경전철용 LIM의 특성에 미치는 영향)

  • Jung, In-Sung;Lee, Ju;Jung, Rak-Gyo;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 1998.11a
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    • pp.129-136
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    • 1998
  • The LIM can be used as a transport system with wheel structure. The structural tolerance cause the airgap unbalance and that effects on the LIM performance. The effect of airgap unbalance on the motor performance such as thrust force, velocity and armature current are investigated by using Finite Element Analysis (FEA). From this numerical works, it is known that the airgap unbalance almost does not effect on the motor performance and LIM for transport system is robust to the structural tolerance.

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An Advanced Prediction Technology of Assembly Tolerance for Vehicle Door (차량도어 조립공차 예측기술 개발)

  • Jeoung, Nam-Yeoung;Cho, Jin-Hyung;Oh, Hyun-Seung;Lee, Sae Jae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.4
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    • pp.91-100
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    • 2018
  • The setting of values on door hinge mounting compensation for door assembly tolerance is a constant quality issue in vehicle production. Generally, heuristic methods are used in satisfying appropriate door gap and level difference, flushness to improve quality. However, these methods are influenced by the engineer's skills and working environment and result an increasement of development costs. In order to solve these problems, the system which suggests hinge mounting compensation value using CAE (Computer Aided Engineering) analysis is proposed in this study. A structural analysis model was constructed to predict the door gap and level difference, flushness through CAE based on CAD (Computer Aided Design) data. The deformations of 6-degrees of freedom which can occur in real vehicle doors was considered using a stiffness model which utilize an analysis model. The analysis model was verified using 3D scanning of real vehicle door hinge deformation. Then, system model which applying the structural analysis model suggested the final adjustment amount of the hinge mounting to obtain the target door gap and the level difference by inputting the measured value. The proposed system was validated using the simulation and showed a reliability in vehicle hinge mounting compensation process. This study suggests the possibility of using the CAE analysis for setting values of hinge mounting compensation in actual vehicle production.

The Regional Characteristics and Effects on the Urban Competitiveness of Urban Creativity (도시 창조성의 지역별 특성과 도시 경쟁력에 미치는 영향)

  • Lee, Joo-Hyung;Kim, Yong-Il
    • KIEAE Journal
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    • v.11 no.5
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    • pp.19-30
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    • 2011
  • This study analysis effects of creativity character on the nation's urban areas and the competitiveness of the urban. The result is that talent of urban creativity effects on the competitiveness of the urban. However, technique and tolerance had not great effect on the competitiveness between cities. After departmentalizing the arrangement of urban creativity, Advanced services constantly appear to affect the competitiveness. Researchers of talent in 2000 and 2005, a culture artistes of tolerance in 2005 and 2009, appeared to affect the competitiveness of urban. In other words, this is changing that the indicators which is impacted on the competitiveness of the urban and each indicator's power with time. According to the result, the study suggests solutions. First, policy direction has to be setting by appropriate the character creativity in urban. Second, there needs the policy which is more focused on talent and tolerance for improving the creativity of urban. For the specific, there needs suggestion about cultural artist and researchers. Finally, considering about changing the urban creativity with time, policy direction has too be setting by reflecting this change.

Comparative Performance of Three Tropical Turfgrasses Digitaria longiflora, Axonopus compressus and St. Augustinegrass under Simulated Shade Conditions

  • Chin, Siew-Wai
    • Weed & Turfgrass Science
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    • v.6 no.1
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    • pp.55-60
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    • 2017
  • Shade affects turf quality by reducing light for photosynthesis. The shade tolerance of the tropical grasses, Digitaria longiflora and Axonopus compressus were evaluated against Stenotaphrum secundatum (St. Augustinegrass). The grasses were established under shade structures that provide 0%, 50%, 75% or 90% shade level for 30 days. A suite of leaf traits, recorded from similar leaf developmental stage, displayed distinct responses to shade conditions. Leaf length, relative to control, increased in all three species as shade level increased. The mean leaf extension rate was lowest in St. Augustinegrass (80.42%) followed by A. compressus (84.62%) and D. longiflora (90.78%). The higher leaf extension rate in D. longiflora implied its poor shade tolerance. Specific leaf area (SLA) increased in all species with highest mean SLA increase in D. longiflora ($348.55cm^2mg^{-1}$)followed by A. compressus ($286.88cm^2mg^{-1}$) and St. Augustinegrass ($276.28cm^2mg^{-1}$). The highest SLA increase in D. longiflora suggested its lowest performance under shade. The percent green cover, as estimated by digital image analysis, was lowest in D. longiflora (53%) under 90% shade level compared to both species. The relative shade tolerance of the three turfgrasses could be ranked as St. Augustinegrass > A. compressus > D. longiflora.

PB-Overexpression of OsZn15, a CCCH-tandem zinc finger protein, increases drought tolerance in rice

  • Seong, So Yoon;Jung, Harin;Choi, Yang Do;Kim, Ju-Kon
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.115-115
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    • 2017
  • Zinc finger proteins constitute a large family which has been studied to have various functions in different organisms. Tandem CCCH zinc finger proteins (TZFs), members of the zinc finger protein family, are known to participate as post-transcriptional regulators of gene expression in eukaryotes. Here, we showed that the OsZn15, a gene for tandem CCCH zinc finger protein, is induced by abiotic stress and its overexpression in transgenic rice plants (PGD1:OsZn15) gains higher drought tolerance. Gene expression analysis of promoter:GFP plants revealed that OsZn15 is specifically expressed in anther and embryo, but not in vegetative organs. In-field evaluation, grain yield was higher in the PGD1:OsZn15 than nontransgenic plants under drought conditions. Interestingly, OsZn15 is shown to not only localize at nucleus but also co-localize with both processing bodies (PB) and stress granules (SG), two messenger ribo-nucleoprotein complexes which are known to activate by forming cytoplasmic foci under stress conditions. In sum, these results suggest that OsZn15 increases drought stress tolerance of rice probably by participating in RNA turnover in PB and SG.

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Relationship between Academic Burnout of Medical and Graduate Students and Related Variables (의과대학·의학전문대학원생의 학업소진 양상과 관련 변인들과의 관계)

  • Chun, Kyung Hee
    • Korean Medical Education Review
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    • v.16 no.2
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    • pp.77-87
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    • 2014
  • The purpose of this study was to investigate the influence of demographic data, academic demand, perfectionism, and academic failure tolerance on academic burnout of medical and graduate students at Yeungnam University. A mixed method study was conducted. Fourteen students participated in a focus group interview and 302 students, including 151 medical students and 151 graduate students, completed a survey, which addressed the factors of academic burnout, academic demand, perfectionism, and academic failure tolerance. There were significant differences in the academic burnout by age and year in school. The 2nd year medical & graduate students experienced significantly higher academic burnout than the other students. Multiple regression analysis revealed that academic burnout of medical and graduate students was significantly affected by academic demand (p<0.001), self-oriented and socially-prescribed perfectionism (p<0.001, p<0.01), and feeling and behavior, which were sub-factors of academic failure tolerance (p<0.05, p<0.01). It is suggested that comparative studies with other student groups, a longitudinal study of medical and graduate students, and a prospective study of coping styles and methods of preventing academic burnout need to be conducted.

Self-Reference PCSR-G Method for Detecting Defect of Flat Panel Display (평판 디스플레이 결함 검출을 위한 자기 참조 PCSR-G 기법)

  • Kim, Jin-Hyung;Lee, Tae-Young;Ko, Yun-Ho
    • Journal of Korea Multimedia Society
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    • v.18 no.3
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    • pp.312-322
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    • 2015
  • In this paper a new defect detection method for flat panel display that does not require any separately prepared reference images and shows robustness against problems with regard to pixel tolerance and nonuniform illumination condition is proposed. In order to perform defect detection under any magnification value of camera, the proposed method automatically obtains the value of pattern interval through an image analysis. Using the information for pattern interval, an advanced PCSR-G method presented in this paper utilizes neighboring patterns as its reference images instead of utilizing any separately prepared reference images. Also this paper proposes a scheme to improve the performance of the conventional PCSR-G method by extracting and applying additional information for pixel tolerance and intensity distribution considering the value of pattern interval. Simulation results show that the performance of the proposed method utilizing pixel tolerance and intensity distribution is superior to that of the conventional method. Also, it is proved that the proposed method that is implemented using parallel technique based on GPGPU can be applied to real system.

Tolerance Optimization of Design Variables in Lower Arm by Using Response Surface Model and Process Capability Index (반응표면모델과 공정능력지수를 적용한 로워암 설계변수의 공차최적화)

  • Lee, Kwang Ki;Ro, Yun Cheol;Han, Seung Ho
    • Korean Journal of Computational Design and Engineering
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    • v.18 no.5
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    • pp.359-366
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    • 2013
  • In the lower arm design process, a tolerance optimization of the variance of design variables should be preceded before manufacturing process, since it is very cost-effective compared to a strict management of tolerance of products. In this study, a design of experiment (DOE) based on response surface model (RSM) was carried out to find optimized design variables of the lower arm, which can meet a given requirement of probability constraint for the process capability index (Cpk) of the weight and maximum stress. Then, the design space was explored by using the central composite design method, in which the 2nd order Taylor expansion was applied to predict a standard deviation of the responses. The optimal solutions satisfying the probability constraint of the Cpk were found by considering both of the mean value and the standard deviation of the design variables.

Analysis of Teenagers' Self-identified Cold Tolerance and Wearing Behavior Inside and Outside the Classroom During Winter (청소년들의 겨울철 교실 내·외 환경에서의 자각적 내한성과 착의행동 분석)

  • Hong, Min-Hyun;Son, Su-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.44 no.1
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    • pp.126-140
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    • 2020
  • This study analyzed the self-identified cold tolerance and wearing behavior of teenagers inside and outside the classroom during winter, considering recent climate changes. A questionnaire was divided into four parts-general information, thermal and comfort sensation inside and outside classroom, self-identified cold tolerance, and wearing behavior to collect data from 322 students. Over several years, changes were noted in respondents' wearing behavior during winter outings, with the biggest being the purchase of a "long padded jacket" for warmth while outside. Most respondents showed similar wearing behavior, such as no difference between the number of clothes worn in a classroom maintained at 20℃ (girls: 8.0±3.1 layer, boys: 6.5±2.1 layer) and outside (girls: 8.8±3.4 layer, boys: 7.1±3.0 layer), despite feeling differently about the thermal sensation inside and outside the classroom. This difference may due to a teenager's lack of knowledge about temperature and their tendency to follow clothing trends. Female students were more sensitive to the cold and wore more garments inside and outside the classroom. Gender-related differences should be considered when educating teenagers about safe and healthy clothing.