• 제목/요약/키워드: failure experience

검색결과 678건 처리시간 0.043초

6 시그마의 적용에 대한 연구 (An Application Study of Six Sigma in Clinical Chemistry)

  • 장상우;김남용;최호성;박용원;추경복;윤근영
    • 대한임상검사과학회지
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    • 제36권2호
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    • pp.121-126
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    • 2004
  • The primary goal of six sigma is to improve patient satisfaction, and thereby profitability, by reducing and eliminating defects. Defects may be related to any aspect of customer satisfaction: high product quality, schedule adherence, cost minimization, process capability indices, defects per unit, and yield. Many six sigma metrics can be mathematically related to the others. Literally, six means six standard deviations from the mean or median value. As applied to quality metrics, the term indicates that failures are at least six standard deviations from the mean or norm. This would mean about 3.4 failures per million opportunities for failure. The objective of six sigma quality is to reduce process output variation so that on a long term basis, which is the customer's aggregate experience with our process over time, this will result in no more than 3.4 defect Parts Per Million(PPM) opportunities (or 3.4 Defects Per Million Opportunities. For a process with only one specification limit (upper or lower), this results in six process standard deviations between the mean of the process and the customer's specification limit (hence, 6 Sigma). The results of applicative six sigma experiment studied on 18 items TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA tests in clinical chemistry were follows. Assessment of process performance fits within six sigma tolerance limits were TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA with 72.2%, items that fit within five sigma limits were total bilirubin, chloride and sodium were 3 sigma. We were sure that the goal of six sigma would reduce test variation in the process.

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A Robust Mobile Video Streaming in Heterogeneous Emerging Wireless Systems

  • Oh, Hayoung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권9호
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    • pp.2118-2135
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    • 2012
  • With the rapid development of heterogeneous emerging wireless technologies and numerous types of mobile devices, the need to support robust mobile video streaming based on the seamless handover in Future Internet is growing. To support the seamless handover, several IP-based mobility management protocols such as Mobile IPv6 (MIPv6), fast handover for the MIPv6 (FMIPv6), Hierarchical MIPv6 (HMIPv6) and Proxy Mobile IPv6 (PMIPv6) were developed. However, MIPv6 depreciates the Quality-of-Service (QoS) and FMIPv6 is not robust for the video services in heterogeneous emerging wireless networks when the Mobile Node (MN) may move to another visited network in contrast with its anticipation. In Future Internet, the possibility of mobile video service failure is more increased because mobile users consisting of multiple wireless network interfaces (WNICs) can frequently change the access networks according to their mobility in heterogeneous wireless access networks such as 3Generation (3G), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMax) and Bluetooth co-existed. And in this environment, seamless mobility is coupled according to user preferences, enabling mobile users to be "Always Best Connected" (ABC) so that Quality of Experience is optimised and maintained. Even though HMIPv6 and PMIPv6 are proposed for the location management, handover latency enhancement, they still have limit of local mobility region. In this paper, we propose a robust mobile video streaming in Heterogeneous Emerging Wireless Systems. In the proposed scheme, the MN selects the best-according to an appropriate metric-wireless technology for a robust video streaming service among all wireless technologies by reducing the handover latency and initiation time when handover may fail. Through performance evaluation, we show that our scheme provides more robust mechanism than other schemes.

인쇄형 색인초록과 전자형 색인초록의 이용행태에 관한 비교연구 (A Comparative Study of Printed versus Digital Index and Abstract Users' Behaviour Patterns)

  • 황금숙
    • 한국문헌정보학회지
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    • 제32권1호
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    • pp.169-187
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    • 1998
  • 본 연구의 목적은 전자형 색인초록이 도서관 및 정보기관에 도입되어 있음에도 불구하고 계속 인쇄형 색인초록을 이용하는 이용자는 어떤 개인적 특성을 보이고 있으며, 어떤 행태를 지니고 있는지를 전자형 색인초록 이용행태와 비교함으로써 인쇄형 색인초록이 지니고 있는 특성을 밝히는데 있다. 결론을 요약하면 이용자들은 논문작성시 확실한 연구논제를 정하지 못한 상태에서 연구의 주제를 얻기 위하여 인쇄형 색인초록을 이용하는 반면, 확실한 논제가 정해진 상태에서는 선행연구조사와 같은 포괄적인 조사를 하기 위해서 전자형 색인초록을 이용하고 있고 인쇄형 색인초록 이용자들은 탐색과정 중 자신에게 필요한 문헌인지 아닌지를 결정하는 판단력으로 인하여 탐색결과 만족도가 전자형 색인초록 이용자보다 다소 더 높으며, 전자형 색인초록 이용자는 인쇄형 색인초록 이용자보다 탐색결과 분석을 위해 별도의 시간을 더 많이 할애하고 있다. 전자형 색인초록 이용자는 인쇄형 색인초록 이용자보다 탐색실패 경험이 더 많았으며, 탐색실패 후 각 유형의 색인초록 이용자 모두 높은 응답율로 다른 색인초록을 통한 재탐색을 시도하였다. 인쇄형 색인초록 이용자는 전자형 색인초록 이용자에 비해 온라인 탐색지식이 월등하게 적은 것으로 나타났다.

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청대 전기의 활자인쇄 (The Type Printing of First Ch'ing Dynasty Term)

  • 조형진
    • 한국문헌정보학회지
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    • 제29권
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    • pp.345-382
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    • 1995
  • The type printing of first Ch'ing dynasty term in China is worthy to be studied because the type printing during that period included metal type, wood type, and clay type as well as the development phase was similar to Chosun dynasty culturally and technologically. This paper studied typography during the first Ch'ing dynasty term, including Shunzhi(1662-1722), Yongaheng(1723-1735), Qianlong(1736-1795), Jiaqing(1796­1820) period. The main results of the study is as follows. 1. The main body of type printing was bookstore, lecture-hall, and individual as well as the royal court that is the central government. 2. The content of type edition covers classics, history, philosophy, and literary works. Specifically, even though Wuyingdienjuzhenban series is excluded, the content includs study of the classics, class of the history, class of the philosophy, literature works that include collection works and novel and government official bulletin. 3. The printing technique of bronze type was very popular In Beijing. Jiangsu, and Taiwan. It's scale and production technique was more elaborate than in Ming dynasty. 4. Wood type was very popular in Beijing, Jiangsu, Zhejiang, Anhui, Sichuan, and Fujian. In addition to wood type, chinese ware type was applied to book printing in Shandong. However, most of them were wood type and they were used after Qianlong period. 5. The production technique of type was skilled enough to present the fine view of a style of type. The typesetting technique was improved as much as woodblock printing. With regard to the making technology of Chinese ink, the light and darkness of chinese ink was not even sometimes. But, the technology was improved significantly when comparing with the failure experience of printing that chinese ink was not developed in early type invention. 6. In case that the book was printed in bookstore with the intention of profit and the number of book was large, the proofreading attitude was rough. However, overally, it was made correction carefully applying the various methods of proofreading. 7. The support of government made a great contribution in the area of all printing technology, including production, typesetting, and brushing of type.

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초미세수술을 이용한 하지재건의 기술적 고찰 (Techniques in Lower Extremity Reconstruction with Supermicrosurgery)

  • 이희종;김성찬;김규남;윤치선;홍준표
    • Archives of Reconstructive Microsurgery
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    • 제22권1호
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    • pp.33-37
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    • 2013
  • Purpose: The concept and development of perforator free flaps have led to significant advances in microsurgery. Ongoing developments in perforator free flap surgery are aimed at reducing complications and improving surgical outcomes. The aim of this study was to evaluate the effectiveness and application of supermicrosurgery in free flap surgery. Materials and Methods: A total of 267 patients with soft tissue defects of the lower extremity due to various etiologies from January, 2007 to January, 2013. The patients received either an anterolateral thigh free flap (n=83), a superficial circumflex iliac artery free flap (n=152), an upper medial thigh free flap (n=19), or a superior gluteal artery perforator free flap (n=13). Microanastomosis was performed using a perforator-to-perforator technique, either end-to-end or end-to-side. Results: The mean postoperative follow up period was eight months (range: one to 16 months) and flap loss occurred in 11 cases out of 267. All cases of flap loss occurred within two weeks of surgery due to either arterial insufficiency (n=5) or venous congestion (n=6). Conclusion: Supermicrosurgery enables the selection of the most efficient perforator for microanastomosis at the defect site. It also reduces the time required for dissection of recipient vessels, and reduces the possibility of injury to major vessels. Microsurgery using a vessel of less than 1 mm has been reported to increase the risk of flap failure; however, using the most advanced surgical tools and developing experience in the technique can produce success rates similar to those found in the literature.

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역위 매복된 상악 중절치의 교정적 처치를 통한 치근 형성유도 (GUIDANCE OF ROOT FORMATION BY FORCED ERUPTION FOR INVERTED MAXILLARY CENTRAL INCISOR)

  • 장은영;임광호;이창섭;이상호
    • 대한소아치과학회지
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    • 제26권4호
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    • pp.644-651
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    • 1999
  • 미맹출된 상악 중절치는 비교적 흔히 임상에서 8세이상의 아동에서 관찰될 수 있다. 맹출실패의 원인으로는 치배의 비정상적인 발육이 언급되는데 아직 명백히 밝혀지지는 않았지만, 이는 외상이나 선행유치의 치근단 감염으로 유발될 수 있다. 본 증례는 외상의 병력이 없어 유치의 치근단 감염에 의한 상악 중절치의 매복을 고려해 볼 수 있다. 치아의 맹출과 Hertwig's epithelial root sheath 에 의한 지속적인 치근 발육을 유도하기 위해서는 외과적 노출과 가철성 장치를 이용한 교정적 견인이 치료방법으로 시행될수 있다. 본 증례는 역위 매복으로 인해 치근의 만곡이 예상되며 치근의 발육이 지연된 치아를 치근형성 전 조기에 가철성 장치를 이용한 교정적 견인에 의해 정상적인 맹출과 인접치와 유사한 치근 발육이 얻어졌다. 하지만 향후 완전한 치근 형성 유무에 대한 주기적인 검진과 부착치은 획득을 위한 치주적인 처치가 필요하리라 사료된다.

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ROLE OF PASSIVE SAFETY FEATURES IN PREVENTION AND MITIGATION OF SEVERE PLANT CONDITIONS IN INDIAN ADVANCED HEAVY WATER REACTOR

  • Jain, Vikas;Nayak, A.K.;Dhiman, M.;Kulkarni, P.P.;Vijayan, P.K.;Vaze, K.K.
    • Nuclear Engineering and Technology
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    • 제45권5호
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    • pp.625-636
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    • 2013
  • Pressing demands of economic competitiveness, the need for large-scale deployment, minimizing the need of human intervention, and experience from the past events and incidents at operating reactors have guided the evolution and innovations in reactor technologies. Indian innovative reactor 'AHWR' is a pressure-tube type natural circulation based boiling water reactor that is designed to meet such requirements, which essentially reflect the needs of next generation reactors. The reactor employs various passive features to prevent and mitigate accidental conditions, like a slightly negative void reactivity coefficient, passive poison injection to scram the reactor in event of failure of the wired shutdown systems, a large elevated pool of water as a heat sink inside the containment, passive decay heat removal based on natural circulation and passive valves, passive ECC injection, etc. It is designed to meet the fundamental safety requirements of safe shutdown, safe decay heat removal and confinement of activity with no impact in public domain, and hence, no need for emergency planning under all conceivable scenarios. This paper examines the role of the various passive safety systems in prevention and mitigation of severe plant conditions that may arise in event of multiple failures. For the purpose of demonstration of the effectiveness of its passive features, postulated scenarios on the lines of three major severe accidents in the history of nuclear power reactors are considered, namely; the Three Mile Island (TMI), Chernobyl and Fukushima accidents. Severe plant conditions along the lines of these scenarios are postulated to the extent conceivable in the reactor under consideration and analyzed using best estimate system thermal-hydraulics code RELAP5/Mod3.2. It is found that the various passive systems incorporated enable the reactor to tolerate the postulated accident conditions without causing severe plant conditions and core degradation.

철도시스템의 안전성 확보를 위해 안전요건이 반영된 시나리오기반의 위험원 분석에 관한 연구 (On the Scenario-Based Hazard Analysis with Safety Requirements Incorporated to Assure Railway Safety)

  • 정호전;이재천
    • 대한안전경영과학회지
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    • 제16권4호
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    • pp.81-90
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    • 2014
  • Modern systems can be characterized by ever-increasing complexity of both the functionality and system scale. Thus, due to the complexity the chances of accidents resulting from systems failure can then be growing. Even worse is that those accidents could result in disastrous damage to the human being and properties as well. Therefore, the need for the developed systems to be assured with systems safety is apparent in a variety of industries such as rail, automobiles, airplanes, ships, oil refinery, chemical production plants, and so on. To this end, in the industry an appropriate safety standard has been published for its own safety-assured products. One of the core activities included in the most safety standards is hazard analysis. A conventional approach to hazard analysis seems to depend upon the scenarios derived from the ones used previously in similar systems or based on former experience. The objective of this paper is to study an improved process for scenario-based hazard analysis. To achieve the goal, the top-level safety requirements have first been reflected in the scenarios. By analyzing and using them, the result has then lead to the development of safety-assured systems. The method of modeling and simulation has been adopted in the generation and verification of scenarios to check whether the safety requirements are reflected properly in the scenarios. Application of the study result in the case of rail safety assurance has also been discussed.

스쿼트 동작 시 웨이트 벨트 착용 전·후에 따른 운동역학적 분석 (Sports Biomechanical Analysis before and after Applying Weight Belt during Squat Exercise)

  • 이정기;허보섭;김용재;이효택
    • 수산해양교육연구
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    • 제28권4호
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    • pp.893-902
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    • 2016
  • The purpose of this study is to investigate the effect of wearing a weightlifting belt, which is an auxiliary equipment used during squat, by measuring and analyzing biomechanical difference in lower limb and proposing safer and to suggest a more effective exercise method for general population. Selected 8 male participants in their 20s who have not performed regular resistance exercise for at least a year, but have experience of performing squat. The comprehensive method of study is as follows: subjects were notified of the purpose of the study and were told to practice warm-up and the squat motion for the experiment for 20 minutes. When the participant believed they were ready to begin, the experiment was started. At controlled points, foot pressure distribution sensor has been installed. Then left and right feet have been placed on the pressure distribution sensor, from which data for successful squat position that does not satisfy the criteria for failure have been collected and computed with Kwon3D XP program and TPScan program. For data processing of this study, SPSS 21.0 was used to calculated mean (M) and standard deviation (SD) of the analyzed values, and paired t-test has been conducted to investigate the difference before and after wearing the weightlifting belt, with p-value of ${\alpha}<.05$. As for time consumed depending on usage of weightlifting belt in squat, statistically significant difference has been found in P2, which is recovery movement. Lower limb angle depending on usage of weightlifting belt in squat has shown statistically significant difference in E1 foot joint(p<. 001). There has been statistically significant difference in E2 knee joint. Foot pressure percentage depending on usage of weightlifting belt in squat were found to be statistically significant (p<. 01) in both regions of anterior and posterior foot.

프로젝트 관리의 성공에 영향을 미치는 장애요인 (Barriers to Success of Project Management)

  • 이아연;문경미;김승철
    • 산업경영시스템학회지
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    • 제43권3호
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    • pp.179-190
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    • 2020
  • As the business environment is rapidly changing with globalization and complexity of information flows, the uncertainty is also very increased for project environment. Although many studies have been conducted to find out the critical factors for project success, there still exist different views to define project success. Furthermore, implementing success formula for one project does not necessarily guarantee a success for another project since there are other elements that impede the success of project. In this regards, it is imperative to examine what are the barriers to project success. This study aims to examine the barriers that impede the success of project. Past literature was thoroughly reviewed to collect and develop a preliminary list of elements that affected project performance negatively. Experts were interviewed to refine the list and the final list of the measurement items were developed. A survey questionnaire was developed with the final list of measurement items, and a survey was conducted on the practitioners with project experience. After the survey, an exploratory factor analysis was conducted on the final list to extract the component dimensions which in turn formed the group of project barriers. The exploratory factor analysis provided ten factors, which are difficulty of process management, failure of project feasibility analysis, cost overruns and lack of cost benefits, unclarity project plan, strategic consistency error, stakeholder conflict, inaccuracy of requirement definition, disturbance of communication, technical environment change, negative attitude of top management.