• Title/Summary/Keyword: operational dimensions

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An Algorithm for Automatic Generation of Dimension and Tolerance Charts (치수/공차표의 자동생성 알고리듬)

  • Jung, Jong-In;Kim, Kwang-Soo;Choi, Hoo-Gon
    • Journal of Korean Institute of Industrial Engineers
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    • v.29 no.1
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    • pp.21-31
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    • 2003
  • Determination of operational dimensions and tolerances is complex if there exist inconsistencies between operational and design specifications. Dimension and tolerance charts (D&T charts) have been used to establish the relationships among operational dimensions in complex machining. This chart proves that individual operations can be harmonized when they are interconnected. However, it is hard to generate the chart manually. Because operational dimensions and tolerances must meet the design specifications, the dimensions and tolerances of interconnected operations have to be verified serially for economical operations. In this paper, the chart is automatically generated from the interconnected operations. More importantly, all operational dimensions and tolerances displayed in the chart have been verified by using LP to meet the design specifications. Finally, the chart is converted to an operational routing sheet that contains a detailed process plan along with cutting speed, feed rate, and operational references based on material hardness, surface finish, and tool nose radius.

an Algorithm for Automatic Generation of a Dimension and Tolerance Chart (치수공차표의 자동생성 알고리즘)

  • 정종인;김광수;최후곤
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.353-357
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    • 2000
  • A dimensioning system in a manufacturing process is often complex, especially when a lot of operations are involved in the process. Determination of operational dimensions and tolerances becomes even more complicated if there exist inconsistencies between operational and design relationships among operational dimensions in machining. This chart furnishes a record of the relationships in an easy-to-grasp form, proves that sufficient stock for a cut is available even under adverse conditions, and also proves that separate operations, when taken together, will harmonize as desired. In this paper, various existing roles of the chart have been extended to an operational routing sheet by generating it automatically, providing machining conditions, and verifying operational tolerances.

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Procedure for Determining Operational Dimension and Tolerance in Process Planning (공정계획에서 작업 치수와 공차 결정을 위한 절차)

  • O, Su-Cheol
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.05a
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    • pp.241-244
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    • 2004
  • Dimension and tolerance are very important factors both in a design stage and in a manufacturing stage. As a part of process planning, the tolerance transfer aims at determining the method for converting design dimensions and tolerances into manufacturing dimensions and tolerances based on a given drawing. A procedure for the tolerance transfer is proposed in this paper. Tolerance chart is a valuable graphical tool for a process planner to determine the manufacturing dimensions and tolerances, and consisted of several steps. Among several steps necessary for making up the tolerance chart, the methods for the identification of dimension chain, the determination of tolerances, and the calculation of operational dimensions are presented by using concepts and new presentation methods. A solution method for each step is derived which will be used to establish the tolerance transfer techniques.

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Investigation the tilling imbalance and dimensional variations of multi-cavity injection molded parts (다수 캐비티의 사출성형품에서 충전의 불균형과 치수편차의 고찰)

  • Kang, M.A.;Kim, Y.K.;Kim, J.M.;Lyu, M.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.10a
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    • pp.266-270
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    • 2007
  • Small injection molded articles such as lens and mobile product's parts are usually molded in multi-cavity mold. The problems occurred in multi-cavity molding are flow imbalance among the cavities. The flow imbalance affects on the dimensions and physical properties of molded articles. First of all, the origin of flow imbalance is geometrical imbalance of delivery system. However, even the geometry of delivery system is balanced well the cavity imbalance is being developed. This comes from the unsuitable operational conditions of injection molding. Among the operational conditions, injection speed is the most significant process variable affecting the filling imbalances in multi-cavity injection molding. In this study, experimental study of flow imbalance has been conducted for various injection speeds and materials. Also, the filling Imbalances were compared with CAE results. The dimensions and physical state of multi-cavity molded parts were examined. The results showed that the filling imbalances vary according to the injection speed and flow property of resins. Subsequently, the imbalanced filling and pressure distribution in the multi-cavity affect on the dimensions and physical states of molded parts.

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Children's Concept of Buddha in the Concrete Operational stage (구체적 조작기 아동의 부처님 개념에 관한 조사연구)

  • Baik, Kyung Im
    • Korean Journal of Child Studies
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    • v.11 no.1
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    • pp.29-44
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    • 1990
  • The present study investigated the concept of Buddha in 9- 12- year-old children who were in the concrete operational stage. The concept of Buddha was investigated in the following dimensions:form, competence and role of Buddha, feelings toward Buddha, and prayer to Buddha. Questionaire data were gathered from 143 children attending the Bulkwang Sunday School Statistical analysis was by Chi square. The children perceived Buddha as (1) a statue or a monk living in their mind and in heaven; and (2) unrestricted and superhuman but different from the creator, keeping an eye on them all the time and everywhere. The role of Buddha was perceived as one of giving blessing with good things to those who pray. The children had diverse feelings of awe, thankfulness, fear and anger toward Buddha. Most of the children were confident that Buddha would respond to their prayers but a few showed some doubt. Children in the concrete operational stage were less credulous than those in the pre-operational stage. More than half of the childen reported that they experience the fulfilment of their prayers. The children had deep faith in attaining Buddhahood.

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Development of a Simplified Version of SC-IQ in Korea (SC-IQ의 간이 측정방법 개발)

  • Kim, Eun-Mi;Bae, Sang-Soo
    • Korean Journal of Health Education and Promotion
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    • v.29 no.1
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    • pp.73-87
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    • 2012
  • Objectives: The purpose of this study was to examine the compositional fitness and independence of the original six dimensions and the newly-designed six dimensions of Integrated Questionnaire for the Measurement of Social Capital[SC-IQ], and to explore the more simplified version for convenient use in public health-related social capital studies. Methods: This study reanalyzed social capital items included in a 2004 community health survey of K-city conducted by Hallym Health Services Research Center. Data was collected from 1,000 adults using core questions of SC-IQ. Explanatory factor analyses to all questions were done, and the new six dimensions were established. Confirmatory factor analyses[CFA] were done on the original and new six dimensions. And then reliability and validity test were done. SPSS 15.0 and AMOS 7.0 were used. Results: The final CFA module to the new SC-IQ exhibited Root Mean Square Error of Approximation[RMSEA] 0.028 and only compositional fitness and independence, and was composed of four dimensions and eight questions, and covers all elements of social capital including structural, cognitive, operational, outcome, bonding and bridging elements. Conclusion: This study demonstrates the utility of a new, simplified version of SC-IQ as well as its convenience.

Safety Management in Norwegian Fish Farming: Current Status, Challenges, and Further Improvements

  • Thorvaldsen, Trine;Storkersen, Kristine;Kongsvik, Trond;Holmen, Ingunn Marie
    • Safety and Health at Work
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    • v.12 no.1
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    • pp.28-34
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    • 2021
  • Background: Safety management is required to ensure health and safety of personnel in Norwegian fish farming. However, few studies have addressed the status and practical relevance of this risk-reducing measure. Methods: This article provides new knowledge through interviews with 35 employees at different company levels, addressing perceptions of various safety management activities according to managers and operational personnel. Results: The interviews show that managers and operational personnel at fish farms agree that the quantity of measures aimed to improve safety has increased in recent years. However, some activities are perceived to have higher practical relevance than others. In general, measures that fit well with the practical reality are well received by the employees at the fish farms. Conclusion: Suggested improvements include involving operational personnel in the design of procedures, considering all risk dimensions that may affect occupational health and safety, and challenging the value of specific safety activities based on a detailed knowledge of the distinctive characteristics of work practice in fish farming.

The Impact of Business Risk-Based Audit Approach on Reducing Unsystematic Risks: Evidence from Jordanian Banks

  • AL-QUDAH, Laith A.
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.343-352
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    • 2021
  • This study aims to identify the impact of the audit approach based on business risks (i.e., external environment risk, operations risk, information risk) in reducing unsystematic risks (i.e., operational risk, credit risk, liquidity risk, capital risk, and administrative risk) in Jordanian banks. To reduce the effect of unsystematic risks and, thus, improve banking performance, an audit approach based on business risks has emerged. To achieve the objectives, this study relied on descriptive statistics and the regression approach to study twenty-five Jordanian banks. The researcher used the intentional sampling method represented by employees of the accounting, financial and control departments in Jordanian banks. Seventeen banks contributed to the study, with a percentage of 68%, totaling 356 employees. A questionnaire was designed to obtain the data, and due to homogeneity among the sampling members, a purposive sample was drawn and 300 questionnaires were distributed. The results of the study found a statistically significant effect of the audit approach based on business risks with its combined dimensions on reducing unsystematic risks in Jordanian banks. The results of the study also found a statistically significant effect of the business risk-based audit approach with its combined dimensions on reducing operational risks in Jordanian banks.

Diameter Evaluation for PHWR Pressure Tube Based on the Measured Data (측정 데이터 기반 중수로 압력관 직경평가 방법론 개발)

  • Jong Yeob Jung;Sunil Nijhawan
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.19 no.1
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    • pp.27-35
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    • 2023
  • Pressure tubes are the main components of PHWR core and serve as the pressure boundary of the primary heat transport system. However, because pressure tubes have changed their geometrical dimensions under the severe operating conditions of high temperature, high pressure and neutron irradiation according to the increase of operation time, all dimensional changes should be predicted to ensure that dimensions remain within the allowable design ranges during the operation. Among the deformations, the diameter expansion due to creep leads to the increase of bypass flow which may not contribute to the fuel cooling, the decrease of critical channel power and finally the deration of the power to maintain the operational safety margin. This study is focused on the modeling of the expansion of the pressure tube diameter based on the operating conditions and measured diameter data. The pressure tube diameter expansion was modeled using the neutron flux and temperature distributions of each fuel channel and each fuel bundle as well as the measured diameter data. Although the basic concept of the current modeling approach is simple, the diameter prediction results using the developed methodology showed very good agreement with the real data, compared to the existing methodology.

Multi-objective parametric optimization of FPSO hull dimensions

  • Lee, Jonghun;Ruy, Won-Sun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.734-745
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    • 2021
  • In order to achieve a good and competitive FPSO design, the building cost and the motion performances are the two most critical and conflicting KPIs to be considered. In this study, the author's previous work (Lee, et al., 2021) on the optimization of an FPSO's hull dimensions with 1800 MBBLs storage capacity at Brazil field was extended using a multi-objective parametric optimization with the hull steel weight and the operability which are closely related to the building cost and the operational cost during the lifetime, respectively. For the purpose of more realistic and practical FPSO design, the constraints related to crew comfort and the safe helicopter take-off and landing operation were newly added. Also, the green water on deck was calculated accurately to check the suitability of the designed freeboard height using a newly developed real-time calculation module for the relative wave elevations. With aids of this updated optimization formulation, we presented multiple optimal FPSO dimensions expressed as a Pareto set which aids FPSO designers to conveniently select the practical and competitive dimensions. The excellence of the developed approach was verified by comparing the optimization results with those of FPSOs dimensioned for operation at West Africa and Brazil field.