• Title/Summary/Keyword: six-sigma

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Random Vibration Analysis of Thick Composite Laminated Plate Using Mixed Finite Element Model (1) (혼합유한요소모델을 이용한 두꺼운 복합적층판의 불규칙 진동해석(1)-이론적 고찰)

  • Seok, Keun-Yung;Kang, Joo-Won
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.190-196
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    • 2004
  • Thick composite laminated plates is considered in 3D finite-element. To consider continuity of transverse stresses and displacement field, mixed finite-element has been developed by using layerwise theory and the minimum potential energy principle. Mixed finite-element has been enforced through the thick direction, Z, of a laminated plate by considering six degree-of-freedoms per node. Six degree-of-freedoms are three displacement components in the coordinate axes directions and three transverse stress components ${\sigma}_z,\;{\tau}_{xz},\;{\tau}_{yz}$. The model maintain the fundamental elasticity relations that are stress-strain relation and displacement-strain relation, because the transverse stress components invoked as nodal degrees of freedom by using the fundamental elasticity relationship between th components of stress and displacement. Random vibration analysis of the model is performed by computing consistent mass matrix and computing covariance in frequency domain technique.

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Assessment of Properties of Error Terms in Design of Experiment (실험계획법에서 오차항의 가정 검토방안)

  • Choe, Seong-Un
    • Proceedings of the Safety Management and Science Conference
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    • 2012.04a
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    • pp.579-583
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    • 2012
  • The Design of Experiment (DOE) is a most practical technique when establishing an optimal condition for production technology in Six Sigma innovation project. This research proposes the assessment of properties of error terms, such as normality, equal variance, unbiasedness and independence. The properties of six nonparametric ranking techniques for checking normality assumption are discussed as well as run test which is used to identify the randomness, and to check unbiased assumption. Furthermore, Durbin-Watson (DW) statistics and ARIMA (p,d,q) process are discussed to identify the serial correlation.

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Development of Computational Orthogonal Array based Fatigue Life Prediction Model for Shape Optimization of Turbine Blade (터빈 블레이드 형상 최적설계를 위한 전산 직교배열 기반 피로수명 예측 모델 개발)

  • Lee, Kwang-Ki;Han, Seung-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.5
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    • pp.611-617
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    • 2010
  • A complex system involves a large number of design variables, and its operation is non-linear. To explore the characteristics in its design space, a Kriging meta-model can be utilized; this model has replaced expensive computational analysis that was performed in traditional parametric design optimization. In this study, a Kriging meta-model with a computational orthogonal array for the design of experiments was developed to optimize the fatigue life of a turbine blade whose behavior under cyclic rotational loads is significantly non-linear. The results not only show that the maximum fatigue life is improved but also indicate that the accuracy of computational analysis is achieved. In addition, the robustness of the results obtained by six-sigma optimization can be verified by comparison with the results obtained by performing Monte Carlo simulations.

DFSS-Based Design of a Hall-Effect Rotary Position Sensor (DFSS 를 이용한 홀 효과 기반 회전형 위치 센서의 설계)

  • Kim, Jae-Eun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.2
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    • pp.231-236
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    • 2012
  • This work presents the application of the DFSS (Design for Six Sigma) methodology to optimizing both the linearity and the sensitivity of the output voltage of a Hall-effect rotary position sensor. To this end, the dimensions and relative positions of a permanent magnet with reference to a Hall sensor are selected as the design factors for a full factorial design. In order to evaluate the output voltage of the rotary position sensor at each run in the experimental design, analytical solutions to the magnetic flux density were obtained using the Biot-Savart law and the relations between the magnetic flux density and the output voltage intrinsic to a Hall sensor. Through measurements of the improved output voltage of the rotary position sensors manufactured using the optimized design factors, the proposed method is shown to be simple and practical.

An Exploratory Study on the Possibility of Creative Quality Management (창조적 품질경영의 가능성에 대한 탐색적 연구)

  • Oh, Hyung-Sool;Seong, Baek-Seo;Kim, Seon-Min
    • Journal of the Korea Safety Management & Science
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    • v.11 no.1
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    • pp.103-113
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    • 2009
  • Motorola which had developed and commercialized wireless telephone and mobile phone for the first time in the world made a decision on the separation of the mobile unit from the Motorola due to the continuous bad performance turn. In addition, the Korean company named Raincom which had developed and commercialized MP3 player have been disappeared since Raincom failed to compete with iPod of Apples. What is the main cause the companies that have been top of the world level weed out of IT product market? For less product life cycle and globalization of market, the company's competitiveness tends to be determined based on company's creative capability, rather than process implementation capability. Thus, companies spent a great amount of time and effort in the introduction of creativity management and R&D activities. However, as company's continuous investment on R&D and innovation activities did not lead to business performance, they starts to pay much attention on the effective R&D and innovation activities. Therefore, this paper tries to solve the limitation of the effectiveness of R&D activities by introducing the concept of 'creative quality'. The creative quality is executed by the creative process, which is designed for getting over the limitation of the traditional brainstorming method. This paper presents the concept so called 'creative quality management' and expects it to be an alternative to conquest the limitation of six sigma management.

Determination of Reactivity by MO Theory. Part 79. MO Theoretical Studies on Aminolysis of Carbamates (MO 이론에 의한 반응성 결정. 제 79 보. 카르밤산염의 가아민 분해반응에 관한 MO 이론적 연구)

  • Byong-Seo Park;Ikchoon Lee;Jeoung Ki Cho;Chang Kon Kim
    • Journal of the Korean Chemical Society
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    • v.36 no.3
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    • pp.366-375
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    • 1992
  • The aminolysis of carbamates are studied MO theoretically using AM1 method. The results indicated that the reactivity is determined by bond-making and-breaking and steric effects; as a result the $B_{AC}2$ mechanism is favored due to favorable contribution of bond formation in agreement with experimental results. We found that although thermal 2+2 reaction is forbidden, it becomes allowed when the total electrons involved are six in a four-center reaction and proceeds by a consecutive onestep mechanism. Comparison of activation barriers show that greater energy is required in breaking a sigma bond compared with the energy required for breaking a $\pi$ bond, by 17 kcal/mol and the six membered ring structure is favored about 5 kcal/mol sterically.

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Effects of a Modified Six-Sigma-Methodology-Based Training Program on Core Competencies in Rehabilitation Nurse Specialists

  • Gu, Jiayi;Luo, Lan;Li, Chengjuan;Ma, Sumin;Gong, Fanghua
    • Journal of Korean Academy of Nursing
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    • v.53 no.4
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    • pp.412-425
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    • 2023
  • Purpose: Nurses play an important role in ensuring patient rehabilitation and are involved in all aspects of multidimensional rehabilitation. Therefore, strengthening rehabilitation nursing education is vital to ascertain high-quality rehabilitation and optimum outcomes. This study examined the effectiveness of a new teaching reform-a modified Six-Sigma-based training program-against a conventional educational program on rehabilitation specialist nurses' core competencies, post-training performance, and satisfaction. Methods: A quasi-randomized controlled trial was conducted to assess the effectiveness of the modified training program. We recruited 56 learners from the 2020 training course at the Hunan Rehabilitation Specialist Nurse Training Base as the control group. Sixty learners from the base's 2021 training course were recruited as the intervention group. Data were collected in a consistent manner from both groups after the training program was implemented. Results: Those who underwent the modified training program showed better improvement in all core competencies than those who underwent the conventional training program (p < .05); the scores for theoretical knowledge, clinical nursing lectures, reviews, and nursing case management improved significantly following the teaching reform (p < 0.05). Further, overall satisfaction as well as base management and theoretical teaching satisfaction improved significantly (p < .05). Conclusion: The modified training program strengthens rehabilitation nurses' base management abilities; enhances their core competencies; expands their interest in and breadth, depth, and practicability of theoretical courses; and updates the teaching methods.

The Study on control factor of WorldSID 50%ile dummy injury through AE-MDB side crash test (AE-MDB 측면 충돌 시험 시 WorldSID 50%ile dummy 상해치에 대한 제어인자 연구)

  • Hongyul Sun;Pyokyong Han;Jaesu Kim;Kiseok Kim;Ilsung Yoon
    • Journal of Auto-vehicle Safety Association
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    • v.6 no.1
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    • pp.5-9
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    • 2014
  • Over the past ten years, since the introduction of the side crash test regulation in Europe, much research work has been performed internationally to develop new and modified test procedures to improve the level of occupant protection offered by vehicles in side crash test. This research has been co-ordinated and finally contributed to development of an AE-MDB(Advanced European Moving Deformable Barrier) and WorldSID (Worldwide Side Impact Dummy). EuroNCAP(European New Car Assessment Program) has the plan to conduct AE-MDB side crash test using WorldSID from 2015 by replacing Progressive MDB and EuroSID II. Automobile manufacturers need to respond to these changes closely. This paper is to find dominant control factor and analyze it of WorldSID 50%ile dummy injury through AE-MDB side crash test by predicting best and worst condition. And control factors will be validated within EuroNCAP regulations. This paper is analyzed by DFSS(Design for six sigma) which contains 5 control factors and is evaluated by ANOVA with the data as a result of LS-DYNA analysis correlated with crash pulse from 50 kph AE-MDB side crash test using WorldSID 50%ile dummy.

Polycyclic Aromatic Hydrocarbons in Industrial Organic Sludge from Wastewater Treatment Facilities in Korea (폐수처리시설에서 발생된 유기성 슬러지에 함유된 다환방향족탄화수소의 농도 특성)

  • Nam, Seong-Nam;Lee, Mi-Young;Yeon, Jinmo;Jeon, Taewan;Shin, Sun Kyoung
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.8
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    • pp.574-582
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    • 2012
  • This study presents the concentrations of the polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by United States Environmental Protection Agency (US EPA), in 98 sludges from 54 industrial wastewater treatment facilities of South Korea. The mean concentrations of ${\Sigma}_{16}PAHs$ were ranged from 32.5 ${\mu}g/kg-dw$ to 1189.3 ${\mu}g/kg-dw$ by industries, and the highest content was found in the petrochemical industry, followed by chemical, clothing manufacturing and dying, pulp and papermaking, secondary wastewater treatment, and food/beverage producing industries. Comparisons to the EU and Danish standards of ${\Sigma}_{16}PAHs$ in sewage sludge for land application showed only two samples (one from petrochemical, and the other from chemical industry) exceeded the limits. ANOVA test with PAH concentrations as variables revealed no statistically significant influences by industrial types and sampling time (i.e., seasonal variations). Pearson correlations between individual PAHs showed strong relationships (r>0.7) among 4-ring PAHs. Concentrations of acenaphthylene, anthracene, fluoranthene, benzo(a)anthracene, benzo(f)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene presented strong correlations to ${\Sigma}_{16}PAHs$. Principal component analysis discriminated entire samples into three groups by two principal components (PC1 and PC2) with 70% of data variations, in which industrial types were not of importance, but a dominance of certain PAHs. Samples in group-I, which is high PC1 and low PC2, were characterized by a dominance of 2-ring PAHs, and in group-II, PC1 and PC2 showed a linear relation, was dominant 4-ring PAHs. Group-III with low PC1 and high PC2 includes 17 samples showing a noticeably high contribution of 3-ring PAHs to ${\Sigma}_{16}PAHs$. This study provides concentrations of PAHs in industrial sludges collected from a wide variety of sources (six industrial types) and two seasons of sampling events, and the comparison of ${\Sigma}_{16}PAHs$ with other studies are also discussed.

Dynamics of All-Optical Switching in Bacteriorhodopsin and its Application to Optical Computing

  • Singh, C.P.;Roy, Sukhdev
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.317-319
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    • 2002
  • All-optical switching has been demonstrated in bacteriorhodopsin (bR) based on nonlinear intensity induced excited state absorption. The transmission of a cw probe laser beam at 410 nm corresponding to the peak absorption of M state through a bR film is switched by a pulsed pump laser beam at 570 nm that corresponds to the maximum initial 8 state absorption. The switching characteristics have been analyzed using the rate equation approach considering all the six intermediate states (B, K, L, M, N and 0) in the bR photocycle. The switching characteristics are shown to be sensitive to life time of the M state, absorption cross-section of the 8 state at probe wavelength ($\sigma$ $\_$Bp/) and peak pump intensity. It has been shown that the probe laser beam can be completely switched off (100 % modulation) by the pump laser beam at relatively low pump powers, for $\sigma$$\_$Bp/ = O. The switching characteristics have been used to design all-optical NOT, OR, AND and the universal NOR and NAND logic gates for optical computing with two pulsed pump laser beams.

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