• 제목/요약/키워드: Process capability index

검색결과 177건 처리시간 0.027초

A Modified Target Costing Technique to Improve Product Quality from Cost Consideration

  • Wu, Hsin-Hung
    • International Journal of Quality Innovation
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    • 제6권2호
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    • pp.31-45
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    • 2005
  • The target costing technique, mathematically discussed by Sauers, only uses the $C_p$ index along with Taguchi loss function and ${\bar{X}}-R$ control charts to set up goal control limits. The new specification limits derived from Taguchi loss function is linked through the $C_p$ value to ${\bar{X}}-R$ control charts to obtain goal control limits. This study further considers the reflected normal loss function as well as the $C_{pk}$ index along with its lower confidence interval in forming goal control limits. With the use of lower confidence interval to replace the point estimator of the $C_{pk}$ index and reflected normal loss function proposed by Spiring to measure the loss to society, this modified and improved target costing technique would become more robust and applicable in practice. Finally, an example is provided to illustrate how this modified and improved target costing technique works.

A direct damage detection method using Multiple Damage Localization Index Based on Mode Shapes criterion

  • Homaei, F.;Shojaee, S.;Amiri, G. Ghodrati
    • Structural Engineering and Mechanics
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    • 제49권2호
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    • pp.183-202
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    • 2014
  • A new method of multiple damage detection in beam like structures is introduced. The mode shapes of both healthy and damaged structures are used in damage detection process (DDP). Multiple Damage Localization Index Based on Mode Shapes (MDLIBMS) is presented as a criterion in detecting damaged elements. A finite element modeling of structures is used to calculate the mode shapes parameters. The main advantages of the proposed method are its simplicity, flexibility on the number of elements and so the accuracy of the damage(s) position(s), sensitivity to small damage extend, capability in prediction of required number of mode shapes and low sensitivity to noisy data. In fact, because of differential and comparative form of MDLIBMS, using noise polluted data doesn't have major effect on the results. This makes the proposed method a powerful one in damage detection according to measured mode shape data. Because of its flexibility, damage detection process in multi span bridge girders with non-prismatic sections can be done by this method. Numerical simulations used to demonstrate these advantages.

6시그마 기법을 통한 병원 급식 서비스 품질 개선 및 환자 만족도 향상 (The Improvement of Hospital Food Service in Quality and Customer Satisfaction by Using 6-sigma Strategy)

  • 정수현;염혜선;손정민
    • 대한영양사협회학술지
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    • 제13권4호
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    • pp.331-344
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    • 2007
  • This study was performed to improve the hospital food service in quality and customer satisfaction by using 6-sigma strategy which was processed by DMAIC methods. The research procedure was as follows; analyzing the main causes of customer dissatisfaction of food service by using numerical method, and then finding out the standardized problem solving methods, and finally reforming food service process. The effectiveness of 6-sigma activity was measured by ‘food service quality index’, ‘customer satisfaction index’ and ‘total food service satisfaction index’. Food service quality index was calculated by adding grade of soup temperature, food service, delivery time, and setting accuracy. Statistical data analyses were completed by using the Minitab Ver. 14. By performing 6 sigma activity, food service quality index was increased from 67 to 79 points (p<0.05) and customer satisfaction index also rise from 73 to 79points (p<0.05). Satisfaction of meals’ taste, diverse menu, food setting accuracy, remove of food service, overall food service were significantly improved(p<0.05). The results of capability analysis in food service quality index, customer satisfaction index, and total food service satisfaction index were improved 2.11$\sigma$ to 2.49$\sigma$, 1.88$\sigma$ to 2.43$\sigma$, and 2.04$\sigma$ to 2.47$\sigma$ respectively (p<0.05). Therefore this study showed that subjective food service improving process could be measured by objective numerical value which might be used for financial value in hospital management.

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공간데이터 구축공정 및 이력 관리시스템 개발 (A Management System for the Process and Metadata of Spatial Data Construction)

  • 최병길;조광희;이형수;조태인
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2004년도 추계학술발표회 논문집
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    • pp.355-360
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    • 2004
  • This study is aimed at developing the system to manage the process and metadata of spatial data construction. The process of spatial data construction is standardized by analyzing knowhow of major firms and the provisions of MOCT(Ministry of the Construction and Transportation), and by appling the development methodology of information system. The system from this study has the capability to manage efficiently the process and metadata of spatial data construction. The process is shown by using index map. Also, it is shown by using Gantt chart and PERT chat after developing the interface for MS Project. The metadata is generated from the process, and managed systematically.

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소구경 관단 성형공정 최적화 (A Study on the Forming Process Optimization of a Small Tube)

  • 이정환;이승훈;오현옥
    • 산업경영시스템학회지
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    • 제33권3호
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    • pp.71-78
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    • 2010
  • The end shape of tube for automobile power steering system has influence on the ability of performance. In this case study, we attempted to optimize the forming process of a small tube using Taguchi experimental design methodology. A preliminary experiment was conducted and four main control factors were selected. The experiment was set up as an $L_9(3^4)$ orthogonal array, and determined the optimal levels of the four factors through the analysis of the experimental results. As a result, the performance characteristic(close adhesion power) of the product was improved about 36%. In addition, the process capability index $C_{pk}$ is enhanced from 0.94 to 6.85.

항공기체구조의 정밀조립 및 동시설계 기술 (Accurate Assembly and Concurrent Design of Airframe Structures)

  • 박문식
    • 대한기계학회논문집A
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    • 제24권4호
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    • pp.811-823
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    • 2000
  • In design and manufacturing airframe structures which are composed of a lot of sub-assemblies and large complex profile shapes it is difficult to reduce so called hardware variations. Accordingly cost increasing factors for manufacturing airframe parts are much more than other machine parts because of the variability of fabricated details and assemlies. To improve cost and quality, accurate assembly methods and DPD techniques are proposed in this paper which are based upon using CAD/CAM techniques, the concept of KC's and the coordinated datum and index throughout the design, tooling, manufacturing and inspection. The proposed methods are applied to produce fuselage frame assemblies and related engineering aspects are described regarding the design of parts and tools in the context of concurrent digital definition. First articles and consequent mass production of frame assemblies shows a great improvement of the process capability ratio from 0.7 by the past processes to 1.0 by the proposed methods in addition to the cost reduction due to the less number of tools, reduced total assembly times and the space compaction needed by massive inventory. The need to achieve better Cpk, however, and future studies to be investigated will be addressed briefly.

항공무기체계 운영의 PBL 성과분석에 관한 연구 (A study on the Performance Analysis of PBL for Air Weapon System)

  • 박근석;윤용현;엄정호
    • 한국항공운항학회지
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    • 제25권4호
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    • pp.52-60
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    • 2017
  • This paper forces on the analysis of the overall outcome regarding Performance Based Logistics(PBL) application for Air Weapon System. We used data from domestically developed aircraft such as KT/A-1 and T-50 as well as data from foreign F-15K aircraft and F100 Engine to analyze the current ROKAF PBL application results. Furthermore, this paper thus suggests various techniques to maximize the outcome of user-based PBL performance such as clarifying the responsibility between customer and the company, developing standardized PBL performance index under TLCSM, PBL related maintenance capacity development, wartime PBL implementation process of domestic/foreign companies and many other schemes based on the analyzed data.

남한 강수 기후와 이분 범주 예보 검증 지수 (The Precipitation Climate of South Korea and the Dichotomous Categorical Verification Indices)

  • 임규호
    • 대기
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    • 제29권5호
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    • pp.615-626
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    • 2019
  • To find any effects of precipitation climate on the forecast verification methods, we processed the hourly records of precipitation over South Korea. We examined their relationship between the climate and the methods of verification. Precipitation is an intermittent process in South Korea, generally less than an hour or so. Percentile ratio of precipitation period against the entire period of the records is only 14% in the hourly amounts of precipitation. The value of the forecast verification indices heavily depends on the climate of rainfall. The direct comparison of the index values might force us to have a mistaken appraisal on the level of the forecast capability of a weather forecast center. The size of the samples for verification is not crucial as long as it is large enough to satisfy statistical stability. Our conclusion is still temporal rather than conclusive. We may need the amount of precipitation per minute for the confirmation of the present results.

타구치 로버스트 계획에서 응용모형의 개발 (Development of Application Models Based on the Robust Design)

  • 최성운
    • 대한안전경영과학회지
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    • 제13권1호
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    • pp.203-209
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    • 2011
  • This study develops three new models that are practically applicable to three stages of Taguchi's robust design, which includes system design, parameter design and tolerance design. In system design, the Multiple Loss Function Analysis(MLFA) and Overall Loss Index(OLI) which reflect upon weight of characteristics and importance of specification are developed. Moreover parameter design presents Process Capability Index(PCI), $C_{PUK}$ and $C_{PLK}$, in order to segregate Signal-To-Noise Ratio(SNR) into accuracy and precision for an evaluation of relative comparison. In addition, tolerance design presents the new model of allowance computation for assembled product which is primarily derived from safety margin(SM) considering functional limit and specification. The guideline of those three new models, which include systematic charts and applicable illustrations, offers convenience for practitioners in the field. Hence, the practical applications could be made with the steps of robust designs such as system design, parameter design and specification allowance design.

수자원의 지속가능성 평가 지수 개발과 구성 요소의 중요도 평가 (Development of Assessment Index for Water Resources Sustainability and Weights Evaluation of It's Components)

  • 강민구;이광만
    • 한국수자원학회논문집
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    • 제39권1호
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    • pp.59-68
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    • 2006
  • 지속가능한 수자원 이용과 관리를 위해서는 유역 내에서 진행되고 있는 수자원과 관련된 활동들이 지속가능한 개발의 개념에 부합하는지 여부를 판단해야 한다. 이를 위해서는 유역의 수자원 이용과 관리에 영향을 미치는 수문, 수질, 사회, 경제 및 환경 요인을 고려한 평가지수가 필요하다. 본 연구에서는 수자원의 지속가능성을 평가할 수 있는 지표들을 선정하고 이들을 통합한 수자원 지속가능성 지수(Water Resources Sustainability Index, WRSI)를 개발하였다. WRSI를 구성하는 구성요소의 중요도(Weight)는 계층적 분석기법(Analytic Hierarchy Process, AHP)을 사용하여 결정하였다 수자원의 지속가능성을 세부적으로 평가하기 위하여 WRSI를 경제적 효율성, 사회적 공평성, 환경적 보전성, 유지관리능력 등 4개 세부기준으로 구분하였다. 세부지수의 구성 지표는 유역조사, 사회 및 경제 통계, 여론조사 및 관련된 선행 연구결과를 분석하고 적합성을 평가한 후 선정하였다. WRSI 구성요소들의 중요도는 127명의 전문가들을 대상으로 설문조사를 실시하여 결정하였다. 세부지수와 구성 지표의 중요도 분석결과는 수자원의 지속 가능한 이용을 위해서 수자원 이용의 효율성과 공평성 증대, 하천 수질을 향상시켜 친수 기능의 복원이 중요하다는 것을 나타냈다. 또한, 수자원 분야에 지속적으로 적정 재원의 투입이 필요하며, 수자원 정책 결정에 대한 주민들의 참여가 필요하다는 것을 나타냈다.