• 제목/요약/키워드: ISO quality management

검색결과 416건 처리시간 0.026초

3차원 좌표 측정기 성능 시험법에 대한 측정 불확도 해석 (Measurement Uncertainty Analysis of Performance Test for Coordinate Measuring Machine)

  • 이승표;강형주;하성규
    • 한국정밀공학회지
    • /
    • 제26권4호
    • /
    • pp.91-99
    • /
    • 2009
  • Because of both precise measurement and efficient quality control, coordinate measuring machines(CMMs) have been widely used in the industry. The purpose of this paper is to present a method to estimate the CMM measurement uncertainty using design of experiments. A factorial design is applied to carry out the performance test proposed by ISO 10360 and to investigate CMM measurement errors associated to orientation and length of the length bar. In order to assess the measurement uncertainty for the performance test, an analysis of the uncertainty components that make up the uncertainty budget has been carried out. The procedure for evaluating the uncertainty of it follows GUM ("Guide to the expression of uncertainty in measurement"). The results show that the proposed method is suitable to investigate CMM performance and determine the contribution of machine variables to measurement uncertainty.

안정 동위원소비를 이용한 농촌하천유역 질산성 질소의 오염원 추정 (Identification of the Sources of Nitrate using Stable Isotope Mass Ratio in Rural Watersheds)

  • 홍영진;권순국;홍성구
    • 한국농공학회지
    • /
    • 제43권4호
    • /
    • pp.120-128
    • /
    • 2001
  • Pollution sources and their environmental contributions were investigated to select the best management practices for the effective control of water quality. The nitrogen isotope mass ratio was determined to estimate the nitrate sources and their contribution. Sampling sites were chosen by calculating effluent loads at each watershed. Two liters each of the surface water samples were collected from four sites at Bokha river and two sites and Gwanri river. They were sequentially prepared through distillation method and analyzed using an isotope ratio mass spectrometer(IsoPrime EA). As revealed by the experimental values obtained the mass ratio values ($\delta$$^{5}$ N) of watersheds with a large amount of nonpoint sources were less than +5 an indication that the samples were influenced by chemical fertilizers. However watersheds with large amount of point sources were influenced not only by chemical fertilizers but also by animal and municipal wastes. The mass ratio values of samples generally decreased during rainy days. But during dry days the mass ratio values well-reflected the nitrate sources and the condition of watersheds. Through this study the nitrogen isotope mass ratio has been found to be useful for estimating nitrate sources and their contribution to the rural watersheds.

  • PDF

Effect of Dietary Fiber Level on the Performance and Carcass Traits of Mong Cai, F1 Crossbred (Mong Cai×Yorkshire) and Landrace×Yorkshire Pigs

  • Len, Ninh Thi;Lindberg, Jan Erik;Ogle, Brian
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제21권2호
    • /
    • pp.245-251
    • /
    • 2008
  • The effects of feeding diets containing 20% (L) or 30% (H) neutral detergent fiber (NDF) (DM basis) on performance and carcass traits were studied in three breeds of pig, including pure Mong Cai (MC), crossbred Landrace$\times$Yorkshire (LY) and crossbred MC$\times$Yorkshire (F1). The experiment had a factorial design with two factors, breed and diet. Eighteen piglets of each breed ($60{\pm}3days$) were randomly allocated to three treatments: L-L, low fiber diet in both growing and finishing periods; L-H, low and high fiber diet in the growing and finishing period, respectively; and H-H, high fiber diet in both periods. The diets were iso-energetic and iso-nitrogenous within feeding period. The main fibrous ingredients of the diets were rice bran and cassava residue. There were no effects of fiber level on daily dry matter feed intake (DMI), expressed as g/kg metabolic body weight (BW0.75), in both feeding periods (p>0.05). DMI was highest for MC, followed by F1 and LY (p<0.001). Average daily gain (ADG) in L-L and L-H was higher than in H-H in the growing period (p<0.001) and overall (p<0.05), while feed conversion ratio (FCR) was higher in H-H than in L-L and L-H in the growing period (p<0.05) and overall, but no significant differences between treatments were found in the finishing period. In both periods, Landrace$\times$Yorkshire had the highest ADG and the lowest FCR, followed by F1 and Mong Cai (p<0.001). There were no interactions between breed and diet for performance and carcass traits. Carcass and dressing percentage was lower for L-H and H-H than for L-L (p<0.05). There were no significant differences among treatments in back fat thickness and lean meat percentage, or in crude protein and ether extract contents of lean meat. Carcass, dressing and lean meat percentage was highest for LY, lowest for MC and intermediate for F1 (p<0.001). It can be concluded that feeding a high fiber diet in the growing period reduced pig performance, but there was no effect in the finishing period. Pure Mong Cai pigs are not particularly suitable for meat purposes, although the F1 cross with Large White had reasonably good growth performance and carcass quality.

천연가스 유량 측정에서 헬름홀츠 자유에너지를 이용한 임계유동함수 계산 (Evaluation of Critical Flow Function by Using Helmholtz Free Energy for Natural Gas Flow Measurement)

  • 하영철;허재영
    • 대한기계학회논문집B
    • /
    • 제37권12호
    • /
    • pp.1167-1173
    • /
    • 2013
  • 본 연구에서는 천연가스 유량 측정에서 2차 표준으로 사용되는 소닉노즐 뱅크 -12개 노즐 패키지로 구성-의 임계유동함수 계산 시간을 1초 이하로 단축하고자 하였다. 이를 위해 AGA 8-dc 상태방정식을 적용한 헬름홀츠 자유에너지를 유도하고 이로부터 적분 항이 없는 열역학 상태량 식을 도출하여 CFF 계산에 적용하였다. 그 결과 CFF 계산 시간이 기존 6.7초/12개에서 0.6초/12개로 크게 감소하는 것을 확인할 수 있었고 이 계산 시간은 가스 성분 수와 거의 무관함도 알 수 있었다. 또한 본 계산 결과의 정확도를 확인하기 위해 기존 CFF 국제비교연구의 결과와 비교한 결과 차이가 없음도 확인하였다.

정량적 평가를 도입한 정보시스템 안정성 진단 평가 모델 (Evaluation Model for the Stability of the Diagnostic Information System Incorporating the Quantitative Evaluation)

  • 임형도;박대우
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2016년도 춘계학술대회
    • /
    • pp.313-316
    • /
    • 2016
  • 현재 국가기간산업과 중요한 민간 기업의 정보시스템 장애나 사고발생 시 국가 차원의 혼란이 발생할 개연성이 높고, 국민편익에 큰 영향을 줄뿐 아니라 기업 비즈니스에도 막대한 타격이 불가피하다. 이는 국가적 관리대상인 정보시스템의 안정성이 금융, 통신, 운송, 에너지 등 국민과 사회에 큰 영향을 미치고 민간기관으로 확대되는 추세이다. 그러나 공공 및 민간 정보화 사업은 개발감리나 CMM(Capability Maturity Model)인증을 통해 목표시스템의 품질을 점검하고 있지만 구축 후 운영되는 정보시스템의 안정성에 대한 품질점검은 추진되지 않거나 일부 안전진단 결과에 대한 충족 미흡으로 활성화 되지 못하고 있는 실정이다. 본 연구에서는 구축 되어지는 정보시스템의 안정성 진단 평가점검체계 개발을 통해 정보시스템의 장애나 사고를 방지함으로써, 서비스 혼란을 최소화하고 고객지향적인 서비스 제공을 보장 할 수 있는 방안을 연구 하고자 한다.

  • PDF

기능안전의 구현을 통한 Systematic Failure의 감축에 관한 연구 (On the Reduction of Systematic Failure by Realizing a Method for Functional Safety)

  • 정호전;박찬우;이재천
    • 대한안전경영과학회지
    • /
    • 제15권4호
    • /
    • pp.161-169
    • /
    • 2013
  • Due to the recent advances in technology, the systems are becoming more demanding in terms of functionality and implementation complexity. Therefore, when system failures are involved in such complex systems, the effects of the related safety issues can also be more serious, thereby causing in the worst case irrecoverable hazards on both human being and properties. This fact can be witnessed in the recent rail systems accidents. In general, the accidents can be attributed to the systematic failure or the random failure. The latter is due to the aging or unsatisfied quality of the parts used in implementation or some unexpected external cause that would otherwise result in accidents whereas the former is usually related to incomplete systems design. As the systems are becoming more complex, so are the systematic failures. The objective of the paper is to study an approach to solving the systematic failure. To do so, at first the system design process is augmented by the functional safety activities that are suggested in the standard IEC 61508. Analyzing the artifacts of the integrated process yields the traceability, which satisfies the requirements for reduction of systematic failure as provided in ISO 26262. In order to reduce systematic failure, the results are utilized in the conceptual design stage of systems development in which systems requirements are generated and functional architecture is developed.

역사기록물(Archives)의 항구적인 보존화 이용 : 보존전략과 디지털정보화 (Permanent Preservation and Use of Historical Archives : Preservation Issues Digitization of Historical Collection)

  • 이상민
    • 기록학연구
    • /
    • 제1호
    • /
    • pp.23-76
    • /
    • 2000
  • In this paper, I examined what have been researched and determined about preservation strategy and selection of preservation media in the western archival community. Archivists have primarily been concerned with 'preservation' and 'use' of archival materials worth of being preserved permanently. In the new information era, preservation and use of archival materials were faced with new challenge. Life expectancy of paper records was shortened due to acidification and brittleness of the modem papers. Also emergence of information technology affects the traditional way of preservation and use of archival materials. User expectations are becoming so high technology-oriented and so complicated as to make archivists act like information managers using computer technology rather than traditional archival handicraft. Preservation strategy plays an important role in archival management as well as information management. For a cost-effective management of archives and archival institutions, preservation strategy is a must. The preservation strategy encompasses all aspects of archival preservation process and practices, from selection of archives, appraisal, inventorying, arrangement, description, conservation, microfilming or digitization, archival buildings, and access service. Those archival functions should be considered in their relations to each other to ensure proper preservation of archival materials. In the integrated preservation strategy, 'preservation' and 'use' should be combined and fulfilled without sacrificing the other. Preservation strategy planning is essential to determine the policies of archives to preserve their holdings safe and provide people with a maximum access in most effective ways. Preservation microfilming is to ensure permanent preservation of information held in important archival materials. To do this, a detailed standardization has been developed to guarantee the permanence of microfilm as well as its product quality. Silver gelatin film can last up to 500 years in the optimum storage environment and the most viable option for permanent preservation media. ISO and ANIS developed such standards for the quality of microfilms and microfilming technology. Preservation microfilming guidelines was also developed to ensure effective archival management and picture quality of microfilms. It is essential to assess the need of preservation microfilming. Limit in resources always put a restraint on preservation management. Appraisal (and selection) of what to be preserved was the most important part of preservation microfilming. In addition, microfilms with standard quality can be scanned to produce quality digital images for instant use through internet. As information technology develops, archivists began to utilize information technology to make preservation easier and more economical, and to promote use of archival materials through computer communication network. Digitization was introduced to provide easy and universal access to unique archives, and its large capacity of preserving archival data seems very promising. However, digitization, i.e., transferring images of records to electronic codes, still, needs to be standardized. Digitized data are electronic records, and st present electronic records are very unstable and not to be preserved permanently. Digital media including optical disks materials have not been proved as reliable media for permanent preservation. Due to their chemical coating and physical character using light, they are not stable and can be preserved at best 100 years in the optimum storage environment. Most CD-R can last only 20 years. Furthermore, obsolescence of hardware and software makes hard to reproduce digital images made from earlier versions. Even if when reformatting is possible, the cost of refreshing or upgrading of digital images is very expensive and the very process has to be done at least every five to ten years. No standard for this obsolescence of hardware and software has come into being yet. In short, digital permanence is not a fact, but remains to be uncertain possibility. Archivists must consider in their preservation planning both risk of introducing new technology and promising possibility of new technology at the same time. In planning digitization of historical materials, archivists should incorporate planning for maintaining digitized images and reformatting them in the coming generations of new applications. Without the comprehensive planning, future use of the expensive digital images will become unavailable. And that is a loss of information, and a final failure of both 'preservation' and 'use' of archival materials. As peter Adelstein said, it is wise to be conservative when considerations of conservations are involved.

개인피폭선량 측정기관의 품질관리기준 개발 (Quality Control of Radiation Dosimetry Service)

  • 이준행;이상복;장근조;이광용;이현구;김혁주;진계환
    • 한국의학물리학회지:의학물리
    • /
    • 제20권4호
    • /
    • pp.253-259
    • /
    • 2009
  • 방사선관계종사자에 대한 개인피폭선량 측정의 정확성 및 신뢰성을 확보함으로써 방사선관계종사자의 건강을 보호하고 국민보건 수준향상에 기여하기 위한 개인피폭선량 측정기관의 선량측정 품질관리 기준을 국제기준에 적합하도록 개발할 필요성이 제기되고 있다. 국내 의료기관에서의 개인선량 관련법은 ANSI N13.11-1993 규정을 참조하고 있으나 미국을 비롯한 해외 여러 나라에서는 시험 범주를 줄이고 기준을 강화한 ANSI N13.11-2001을 이미 반영하여 개인피폭선량을 측정하고 있다. 제안하는 방법은 ANSI N13.11-2001을 참고하여 기준을 단순화하였고 유리선량계와 광자극선량계 같은 현재 법률에서 인정하지 않는 첨단기술을 이용하는 것을 막거나 방해할 수 있는 조치를 취하지 않으려고 하였다. 본 논문에서 제안하는 측정기관 품질관리기준은 개인피폭선량 성능시험기준은 관련법규개정에 참고할 수 있고, 측정기관 지도 감독에 활용할 수 있다.

  • PDF

중소 경호.경비업체의 개인정보 유출 방지를 위한 보안 체계 연구 (Privacy leakage security system research for small physical companies)

  • 강푸름;이동휘;김귀남
    • 융합보안논문지
    • /
    • 제12권5호
    • /
    • pp.87-97
    • /
    • 2012
  • 최근 개인정보유출 사건이 빈번히 발생함에 따라 개인정보보호의 문제는 우리 사회의 가장 중요하고 민감한 사회적 의제로 급부상하고 있다. 실제로 개인정보는 그 종류나 유형, 경제적 가치와 민감성, 정보의 질 등에 따라 유출 시 심각한 사회적 위협을 야기할 수 있기 때문에 보다 정확하고 체계적인 개인정보보호 및 관리가 이루어지지 않을 경우 정보화 사회에 큰 혼란을 초래할 수 있다. 특히 업무에 있어 고객의 민감한 개인정보를 필요로 하는 중소 경호 경비업체의 경우, 수집한 정보가 유출 될 시 고객 신변이나 업체의 영업 비밀이 외부에 노출 되 심각한 위협이 있을 수 있어 더욱 큰 문제를 야기한다. 그러나 중소 경호 경비업체는 대기업에 비해 자금의 정도, 인력 부족 등의 문제로 인하여 자체 보안 시스템 구축에 많은 어려움이 있다. 따라서 본 연구에서는 경호 경비업체의 실정을 살펴보고, 그 중 중소 경호 경비업체들이 차지하는 규모와 정보보호의 현황, 특징들을 분석하여 정보보호 시스템 마련의 현실적 문제점 해결 방안으로 중소 경호 경비업체의 개인정보유출 방지를 위한 보안체계를 제안한다.

천연가스의 임계유동함수 불확도 평가 (Estimation of Uncertainty in Critical Flow Function for Natural Gas)

  • 하영철
    • 대한기계학회논문집B
    • /
    • 제38권7호
    • /
    • pp.625-638
    • /
    • 2014
  • 본 연구에서는 천연가스 유량 측정에 사용되는 임계유동함수(CFF)를 AGA8-dc 상태방정식으로 계산할 때 CFF 계산값의 불확도를 평가하였다. CFF 계산에 사용되는 엔탈피, 엔트로피, 음속 식은 불확도 분석이 가능하도록 무차원 헬름홀츠 자유에너지(Helmholtz free energy, HFE)와 이의 편도함수로 표현하였고, HFE의 불확도를 추정하였다. 압축인자의 불확도에 의해 유발되는 종속 변수의 불확도를 반영하기 위해 AGA8-dc 압축인자 식을 해당 불확도만큼 편차가 생기는 형태로 변형하였고, 각 불확도 요인별로 불확도 기여도 평가 모델을 만들었으며, 이를 CFF 계산 프로그램에 적용하였다. 그 결과 CFF의 불확도는 압력 10, 50, 100 bar 에서 각각 0.025, 0.055, 0.112 % 정도로 평가 되었고 압력에 비례하여 증가하는 것을 확인하였다. 또한 본 결과를 기존 CFF 국제비교시험결과(1999년)에 적용한 결과 각 기관별 CFF 값의 차이를 적절히 설명하는 것도 알 수 있었다.