• Title/Summary/Keyword: Six Sigma.

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A Study on Quality Assurance in Auto-parts Research & Development Stage with APQP and DFSS (APQP와 DFSS를 연계한 자동차부품연구개발 단계에서 품질보증에 관한 연구)

  • Lee, Kang-In;Kim, Jae-Hyu
    • Journal of Korean Society for Quality Management
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    • v.39 no.1
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    • pp.131-140
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    • 2011
  • Today, due to the global recession car sales have been decreased rapidly and auto makers are competing continuously to expand their market share. Automakers are struggling in order to secure competitive cost and quality through continuous cost reduction and quality innovation activities to win in the competition. In this situation, auto parts makers are trying to reinforce price competitiveness by reducing COPQ (Cost Of Poor Quality) in the mass production stages by securing the quality of components in advance from the design stage through DFSS (Design For Six Sigma) activities which is 6 sigma approach in the R&D field. However, auto parts makers have been undergone various confusion, feeling difficulties to get interrelationship among various activities. Thus, this study is going to suggest approach method for much more effective R&D activities by securing interrelationship between ISO/TS 16949 system established in the auto parts industry and DFSS activities.

Behavior of High Strength Reinforced Concrete Wide Beam-Column Joint with Slab (슬래브가 있는 고강도 철근 콘크리트 넓은 보-기둥 접합부의 거동)

  • 최종인;안종문;신성우;박성식;이범식;양지수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.493-498
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    • 2002
  • An experimental investigation was conducted to study the behavior of high-strength RC wide beam-column joints with slab subjected to reversed cyclic loads under constant axial load. Six half scale interior wide beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including three specimens without slab and three specimens with slab. The primary variables were compressive strength of concrete( $f_{ck}$ =240, 500kgf/c $m^2$), the ratio of the column-to-beam flexural capacity( $M_{r}$=2$\Sigma$ $M_{c}$$\Sigma$ $M_{b}$ ; 0.77-2.26), extended length of the column concrete($\ell$$_{d}$ ; 0, 9.6, 30cm), ratio of the column-to-beam width(b/H ; 1.54, 1.67). Test results are shown that (1) the behavior of specimen using high-strength concrete satisfied the required minimum ductile capacity according to increase the compressive strength, (2). In the design of the wide beam-column joints, one should be consider the effects of slab stiffness which is ignored in the current design code and practice.ice.e.e.

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Output-error state-space identification of vibrating structures using evolution strategies: a benchmark study

  • Dertimanis, Vasilis K.
    • Smart Structures and Systems
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    • v.14 no.1
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    • pp.17-37
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    • 2014
  • In this study, four widely accepted and used variants of Evolution Strategies (ES) are adapted and applied to the output-error state-space identification problem. The selection of ES is justified by prior strong indication of superior performance to similar problems, over alternatives like Genetic Algorithms (GA) or Evolutionary Programming (EP). The ES variants that are being tested are (i) the (1+1)-ES, (ii) the $({\mu}/{\rho}+{\lambda})-{\sigma}$-SA-ES, (iii) the $({\mu}_I,{\lambda})-{\sigma}$-SA-ES, and (iv) the (${\mu}_w,{\lambda}$)-CMA-ES. The study is based on a six-degree-of-freedom (DOF) structural model of a shear building that is characterized by light damping (up to 5%). The envisaged analysis is taking place through Monte Carlo experiments under two different excitation types (stationary / non-stationary) and the applied ES are assessed in terms of (i) accurate modal parameters extraction, (ii) statistical consistency, (iii) performance under noise-corrupted data, and (iv) performance under non-stationary data. The results of this suggest that ES are indeed competitive alternatives in the non-linear state-space estimation problem and deserve further attention.

Low-temperature Mechanical Behavior of Super Duplex Stainless Steel Considering High Temperature Environment (고온 환경의 영향을 고려한 슈퍼듀플렉스 강의 저온 기계적 거동 평가)

  • Kim, Myung-Soo;Jung, Won-Do;Kim, Jeong-Hyeon;Lee, Jae-Myung
    • Journal of Ocean Engineering and Technology
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    • v.28 no.4
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    • pp.306-313
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    • 2014
  • Super duplex stainless steels (sDSS) are excellent for use under severely corrosive conditions such as offshore and marine applications like pipelines and flanges. sDSS has better mechanical properties and corrosion resistance than the standard duplex stainless steel (DSS) but it is easier for a sigma phase to appear, which depresses the mechanical property and corrosion resistance, compared to DSS, because sDSS has a higher alloy element than DSS. In addition, sDSS has a feeble ductile-brittle transition temperature (DBTT) because it has a 50% ferrite microstructure. In the actual operating environment, sDSS would be thermally affected by welding and a sub-zero temperature environment. This study analyzed how precipitated sDSS behaves at a sub-zero temperature through annealing heat treatment and a sub-zero tensile test. Six types of specimens with annealing times of up to 60 min were tested in a sub-zero chamber. According to the experimental results, an increase in the annealing time reduced the elongation of sDSS, and a decrease in the tensile test temperature raises the flow stress and tensile stress. In particular, the elongation of specimens annealed for 15 min and 30 min was clearly lowered with a decrease in the tensile test temperature because of the increasing sigma phase fraction ratio.

A Study on Identifying Factors Affecting Improvement for Academic Libraries Multimedia Services Using Six Sigma Methodology (6시그마 도구를 활용한 대학도서관 멀티미디어 서비스 개선 변수 도출에 관한 연구)

  • Noh, Dong-Jo;Nam, Min-Seok
    • Journal of the Korean Society for information Management
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    • v.30 no.1
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    • pp.111-129
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    • 2013
  • This study analyzed the process of multimedia services and indexed the core quality characteristics through the tools employed in 'Define' and 'Measure' steps of the 6 Sigma DMAIC methodology. To achieve the goal, as a case study of 'S' University Central Library, first, brainstorming technique was used to tap the librarians, second, interview with the half-time student workers, third, user's opinion on homepage was analyzed and lastly, the interview with the users. This study also drew some potential causal factors which would likely to affect the multimedia service using Process Map and C&E Diagram. Those factors were prioritized using X-Y matrix and Pareto Chart. This study revealed 14 factors affecting multimedia services: 'presence/absence of the persons who are in charge of selection', 'cycle of selection materials', 'presence/absence of seperated multimedia room', 'materials arrangement method', 'notification of popular materials', 'notification of documents arrivals', 'methods of noticing new arrivals', 'methods of ordering materials', 'cycle of checking order status', 'types of persons requesting materials', 'methods of requesting materials', 'checking of the status of the returned materials', 'methods of noticing materials in housed', and 'methods of ways to return overdue materials'.

Development of Standard Method for Quality Innovation to Strengthen Global Competitiveness and Create Management Performance of Small and Medium-sized Manufacturing Firms (중소 제조기업의 글로벌 품질경쟁력 강화 및 경영성과 창출을 위한 품질혁신 표준방법론 개발)

  • Park, Jong Kab;Kim, Youn Sung
    • Journal of Korean Society for Quality Management
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    • v.46 no.4
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    • pp.843-862
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    • 2018
  • Purpose: The purpose of this study was to develop quality innovation techniques specialized for the small and medium-sized businesses. which account for the majority of Korean companies, were having a hard time utilizing the widely recognized quality innovation techniques due to resource constraints. Methods: First, we do review the existing Single PPM and 6 Sigma. And investigate the utilization of these methods including Toyota Production System. Second, we devised a four-step problem-solving methodology based on recent trends in quality innovation such as Simple, Speedy, and Smart. Third, we do survey on frequently used tools for quality innovation. Many opinion leaders including quality consultants and professors answered and gave us valuable comments about our selected quality tools. Finally, we do specify and map tools to each step of PASS. Results: In 2017, 167 companies participated in the quality innovation support business for small businesses according to the Korea Chamber of Commerce & Industry. We conducted performance checks on 167 companies that had completed the "PASS" projects. For the purpose of evaluating improvement performance, the survey was carried out using a structured questionnaire during the field visit of these companies mentioned above. For the reference, 165 out of 167 companies (98.8 % response rate) responded to the questionnaire and conducted performance analysis based on it. According to the survey, 97.6 percent of the respondents were very satisfied with their overall satisfaction with the quality innovation support projects for small and medium sized enterprises in 2017. Also, 93.3 % of the respondents were satisfied with the results of level of the target achievement. As a result, 160 companies (97.0 % of the participating companies) hope to partic ipate in the quality improvement project using "PASS" once again. Conclusion: In this paper, we introduce the new quality innovation methodology, which is named as 'PASS', It could support the long-range business plan of the small and medium-sized businesses to achieve total customer satisfaction resulting in increased market share and improved profit margin. The most small companies can use this "PASS" technique more easily, quickly and most efficiently than their existing known quality innovation techniques such as Six Sigma and Single PPM, etc.

A Case Study on the Lean Management Activity in Business-Services Industry (사무.서비스 산업의 린 경영 활동에 관한 사례 연구)

  • Lee, Kang-In;Lee, Soon-San
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.1
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    • pp.189-206
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    • 2012
  • It is urgently requested to innovate the management process of business-service areas in all industry such as financial business, services and manufacturing because of recent business trend - de-manufacturing trend and the weight increment of service in all industries. Many enterprises introduce various management - innovation methodologies in order to meet the rapidly changing business environment. Especially in Korea, it is a vogue to introduce the innovation methodology of the advanced company's. According to this style, the six sigma has been introduced over 10 years since late 1990's and it has become a synonym of innovation indeed. But the result of six sigma introduction has not reached to the level of expectation in its beginning. And the "Lean" have been introduced in Korea in the situation of global financial crisis, economic slump and the pursuit of developing country such as China. Many Korea companies pay attention to the "Lean" innovation activity because the TPS(Toyota Production System) is the matrix of Lean and is the motive power of Toyota growth. In this study, it was analyzed for the evolution course, distinctive features and effects of Lean management and was examined for the difference of Lean management between manufacturing industry and business-service areas. From this results, the characteristics of Lean management in business-service was analyzed. After survey of innovation agent in Korea company, the Lean model of business-service Industry was developed and applied. This study will be worthy to show the right direction to the enterprises which are to apply lean methodologies, or the enterprises which examine lean management for competitive advantages or the peoples who research the same topics.

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Genetic identification of Aeromonas species using a housekeeping gene, rpoD, in cultured salmonid fishes in Gangwon-Do (강원도 양식 연어과 어류에서 분리된 에로모나스 종의 유전학적 동정)

  • Lim, Jongwon;Koo, Bonhyeong;Kim, Kwang Il;Jeong, Hyun Do;Hong, Suhee
    • Journal of fish pathology
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    • v.30 no.2
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    • pp.79-88
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    • 2017
  • At the present, fish farms are suffering a lot of economic losses due to infectious diseases caused by various pathogens including aeromonad. Aeromonad is ubiquitous bacteria that causes infectious diseases. At least 26 species in the genus Aeromonas have been reported to cause fatal infections not only in salmonid fishes, but also in other freshwater and seawater fishes. Molecular techniques based on nucleic acid sequences of 16S rDNA and housekeeping genes can be used to identify the Aeromonas species. In this study, The genus Aeromonas was isolated from salmonid fishes of sixteen fish farms in Gangwon-Do, Korea and phylogenetically identified based on the sequences of 16S rDNA and housekeeping genes for Aeromonad, i.e. RNA polymerase sigma factor ${\sigma}^{70}$ (rpoD) or DNA gyrase subunit B (gyrB). Consequently, 96 strains were collected from Atlantic salmon (Salmo salar), coho salmon (Oncorhynchus kisutch), masou salmon (Oncorhynchus masou) and rainbow trout (Oncorhynchus mykiss), and 36 isolates were identified as the genus Aeromonas by 16S rDNA analysis. Thirty six Aeromonad isolates were further analysed based on rpoD or gyrB gene sequences and found Aeromonas salmonicida (24 isolates), A. sobria (10 isolates), A. media (1 isolates) and A. popoffii (1 isolates), indicating that A. salmonicida is a main infectious bacteria in Salmonid fishes in Gangwon-Do. It was also proved that the phylogenetic identification of Aeromonas species based on the sequences of housekeeping gene is more precise than the 16S rDNA sequence.

Energy Performance Evaluation of Low Energy Houses using Metering Data (실측데이터를 이용한 저에너지주택의 에너지성능평가)

  • Baek, Namchoon;Kim, Sungbum;Oh, Byungchil;Yoon, Jongho;Shin, Ucheul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.369-374
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    • 2015
  • This study analyzed analyzes the energy performance of six houses in Daejeon completed which were built in 2011. Observed The observed houses, which were all designed and constructed inof the same size and structure, are were highly insulated with triple Low-E coating windows; the insulation level of the walls is was $0.13W/m^2K$ and that of the roof is was $0.10W/m^2K$. As electric houses, all of the energy supplied to the houses, including for cooking, is was supplied by electricity. A and 3~4 kWp of photovoltaic system and a 3~5 kW of ground source heat pump (GSHP) were installed in each house tofor providing provide space heating/and cooling and hot water are installed. We constructed a Web-based remote monitoring system in order to understand energy consumption and the dynamic behavior of the energy system. T, and the results of our metering data analysis of 2013 are as follows. First, the annual residential energy consumption is was 4,400 kWh (${\sigma}=1,209$) and GSHP energy consumption is was 5,182 kWh (${\sigma}=1,164$). Second, residential energy consumption ranked highest in average energy usage, with at 45% of the total, followed by heating with at 30%, hot water supply with at 17% and cooling with at 6%. Third, the average energy independence rate is was 51.8%, the GFA (Gross gross floor area) criteria average energy consumption unit is was $48.7kWh/m^2yr$ (${\sigma}=10.1$), and the net energy consumption unit (except the energy yield of the PV systems) is was $24.7kWh/m^2yr$ (${\sigma}=8.8$).

Development of Geochemical Tracers to Identify a Specific Source Region of Mineral Dust in China and Preliminary Test of Their Applicability (중국 기원 광물성 먼지 입자의 지화학 추적자 개발 및 기초 적용연구)

  • Lee, Sojung;Hyeong, Kiseong;Kim, Wonnyon;Kim, Tae-Hoon
    • Ocean and Polar Research
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    • v.41 no.3
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    • pp.169-181
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    • 2019
  • The purpose of this study is to develop geochemical tracers to identify a specific source desert of mineral dust in China using the published data. In addition, we tested the applicability of these tracers to wet-deposits and soil samples collected in Jeju, Korea. Because of similarity in trace elemental compositions of mineral dust from the major arid regions in China, such as Taklimakan, West Ordos (Badain Jaran), East Ordos (Mu Us and Hobq), East Northern China (Horqin), West Northern China (Gurbantunggut), and Chinese Loess Plateau, there has been limited to the use of geochemical data for source identification. Here we propose the four (4) plots using combination of seven (7) geochemical variables as a source indicator to distinguish one from other source regions in China: $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$, where $_N$ and $\(\frac{Ce}{Ce}\)_N^*$ stand for values normalized to Post-Archean Average Shale composition and Ce anomaly, respectively. Mineral dusts from aforementioned six major deserts are distinguished one from the others by the combined use of these variables. Jeju rock and soil samples form a separate domain from Chinese mineral dusts in all four plots. In contrast, most of Jeju dust samples were comparable with the West Ordos desert (Badain Jaran) domain, indicative of strong influence of Badain Jaran dust in Jeju in spring season when the mineral dust was collected. A weak positive Ce anomaly in Jeju samples implies minimal local contribution. Our study suggests that the combination of $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$ can be used to identify a specific source region of mineral dust in China as well as Jeju mineral particles.