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Characterization of machine tools and measurement system for micromilling

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Nanotechnology and Precision Engineering 2019年第1期2卷 23-28页

作者： Andrea Abeni Matteo Lancini Aldo Attansio department of Mechanical and industrial Engineering University of Brescia

Technological progress has led to increased demand for small components with tiny features, which cannot be achieved through conventional machining. industrial application of processes based on microcutting is limited by some issues concerning the geometrical scale. The process performance is significantly affected by milling machine, tool holder, tool, workpiece material microstructure, workpiece fixtures, and process parameters. At present, an ultimate micromachining assessment procedure is not available. This study aims to propose and conduct an experiment on a testing procedure for micromilling. The set up to be implemented and the output to be considered are defined and described. Three major stages are identified: estimation of the effective bandwidth of the load cell–tool holder system, the milling machine natural frequency measurement, and micromilling test execution. The entire procedure is performed, and its robustness is demonstrated.

关键词： Micromilling Machine tool performance test Tool run-out Force analysis Modal analysis

Consideration of transient heat conduction in a semi-infinite medium using homotopy analysis method

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Applied Mathematics and Mechanics(English Edition) 2008年第12期29卷 1625-1632页

作者： A. Rezania A. Ghorbali G. Domairry H. Bararnia department of Mechanical Engineering Babol Industrial University

In the current work, transient heat conduction in a semi-infinite medium is considered for its many applications in various heat fields. Here, the homotopy analysis method （HAM） is applied to solve this problem and analytical results are compared with those of the exact and integral methods results. The results show that the HAM can give much better approximations than the other approximate methods： Changes in heat fluxes and profiles of temperature are obtained at different times and positions for copper, iron and aluminum.

关键词： homotopy analysis method semi-infinite medium conduction transient heat transfer integral methods temperature profile

Transition Modelling Implications in the CFD Analysis of a Turbine Nozzle Vane Cascade Tested Over a Range of Mach and Reynolds Numbers

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Journal of Thermal Science 2015年第6期24卷 526-534页

作者： Michele Marconcini Roberto Pacciani Andrea Arnone University of Florence Department of Industrial Engineering Via Santa Marta

The aerodynamic performance of a gas turbine nozzle vane cascade was investigated over a range of Mach and Reynolds *** work is part of a vast research project aimed at the analysis of fluid dynamics and heat transfer phenomena in cooled *** this paper computed results on the"solid vane"(without cooling devices)are presented and discussed in comparison with experimental *** measurements were provided by the University of Bergamo where the experimental campaign was carried out by means of a subsonic wind *** impact of boundary layer transition is investigated by using a novel laminar kinetic energy transport model and the widely used Langtry-Menterγ-Reθ,t *** comparison between calculations and measurements is presented in terms of blade loading distributions,total pressure loss coefficient contours downstream of the cascade,and velocity/turbulence-intensity profiles within the boundary layer at selected blade surface locations at *** will be shown how transitional calculations compare favorably with experiments.

关键词： Gas turbine CFD validation transition model secondary flows

PREDECESSOR-SET TECHNIQUE FOR RELIABILITY EVALUATION OF A STOCHASTIC MANUFACTURING SYSTEM

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Journal of Systems Science and Systems Engineering 2015年第2期24卷 190-210页

作者： Yi-Kuei Lin Ping-Chen Chang department of industrial Management National Taiwan University of Science & Technology

This paper studies the reliability evaluation of a stochastic manufacturing system with multiple production lines in parallel. Multiple repairs and different failure rates, never simultaneously addressed in earlier works, are taken into account. First, a revised graphical methodology integrating transformation and decomposition is utilized to construct the stochastic manufacturing system as a multi-state manufacturing network （MSMN）. In particular, a ＂predecessor-set＂ technique is proposed to deal with multiple repairs. An algorithm is proposed to generate the lowest capacity vectors （LCVs） that stations should provide to satisfy the workloads. Subsequently, the system reliability of the MSMN, which is defined as the probability of demand satisfaction, is calculated in terms of the LCVs. A real case of a printed circuit board manufacturing system is utilized to demonstrate how the system reliability can be evaluated. A further decision making issue is addressed based on the derived system reliability.

关键词： Multi-state manufacturing network (MSMN) predecessor-set lowest capacity vector(LCV) different failure rates multiple repairs system reliability

Optimization of Steel Bar Manufacturing Process Using Six Sigma

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 332-341页

作者： NAEEM Khawar ULLAH Misbah TARIQ Adnan MAQSOOD Shahid AKHTAR Rehman NAWAZ Rashid HUSSAIN Iftikhar department of industrial Engineering University of Engineering and Technology(UET) Peshawar

Optimization of a manufacturing process results in higher productivity and reduced wastes. Production parameters of a local steel bar manufacturing industry of Pakistan is optimized by using six Sigma-Define, measure, analyze, improve, and controlmethodology. Production data is collected and analyzed. After analysis, experimental design result is used to identify significant factors affecting process performance. The significant factors are controlled to optimized level using two-level factorial design method. A regression model is developed that helps in the estimation of response under multi variable input values. Model is tested, verified, and validated by using industrial data collected at a local steel bar manufacturing industry of Peshawar（Khyber Pakhtunkhwa, Pakistan）. The sigma level of the manufacturing process is improved to 4.01 from 3.58. The novelty of the research is the identification of the significant factors along with the optimum levels that affects the process yield, and the methodology to optimize the steel bar manufacturing process.

关键词： steel bar manufacturing industry six sigma yield sigma level design of experiments

Research on the Work-rest Scheduling in the Manual Order Picking Systems to Consider Human Factors

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Journal of Systems Science and Systems Engineering 2019年第3期28卷 344-355页

作者： Xiaosong Zhao Na Liu Shumeng Zhao Jinhui Wu Kun Zhang Rui Zhang department of industrial Engineering Tianjin UniversityTianjin 300072China

As the status of order picking in the warehousing and distribution system has been raised,the work-rest scheduling of picking becomes particularly *** science and technology have developed rapidly,manual picking is still essential and ***,previous researches focused on the study of the sequencing,ignoring human *** paper presents a work-rest schedule model in parts to picker picking *** objectives are proposed that include minimizing the picking time and minimizing picking error *** workers'fatigue,workload is taken into account in the manual order picking systems because the fatigue can have a large influence on the picking time and the picking error rate.A genetic algorithm is used to solve a multi-objective optimization problem that the model concerns and looking for a Pareto front as the most effective methods for solving this *** the original data is given,the work-rest scheduling model is built and the work sequence,and the number of breaks are determined to be chosen by decision *** addition,a case study of the model is used to confirm that the model is effective and it is necessary to consider the human factor in the picking system.

关键词： Work-rest schedule picking system fatigue workload picking error rate

Biclustering of ARMA time series

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第12期11卷 959-965页

作者： Jeonghwa LEE Chi-Hyuck JUN department of industrial and Management Engineering Pohang University of Science and Technology

Biclustering is a method of grouping objects and attributes simultaneously in order to find multiple hidden *** dealing with a long time series,there is a low possibility of finding meaningful clusters of whole time ***,we may find more significant clusters containing partial time sequence by applying a biclustering *** paper proposed a new biclustering algorithm for time series data following an autoregressive moving average (ARMA) *** assumed the plaid model but modified the algorithm to incorporate the sequential nature of time series *** maximum likelihood estimation (MLE) method was used to estimate coefficients of ARMA in each *** applied the proposed method to several synthetic data which were generated from different ARMA *** from the experiments showed that the proposed method compares favorably with other biclustering methods for time series data.

关键词： Biclustering Time series Autoregressive moving average (ARMA) Maximum likelihood estimation (MLE)

Geometrically Nonlinear Bending Analysis of Metal-Ceramic Composite Beams under Thermomechanical Loading

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Chinese Journal of Mechanical Engineering 2013年第4期26卷 701-713页

作者： TORABIZADEH Mohammad Amin department of industrial Design Engineering University of Applied Science and Technology

A new method is developed to derive equilibrium equations of Metal-Ceramic beams based on first order shear deformation plate theory which is named first order shear deformation beam theory2(FSDBT2). Equilibrium equations obtained from conventional method (FSDBT1) is compared with FSDBT2 and the case of cylindrical bending of Metal-Ceramic composite plates for non-linear thermomechanical deformations and various loadings and boundary conditions. These equations are solved by using three different methods (analytical, perturbation technique and finite element solution). The through-thickness variation of the volume fraction of the ceramic phase in a Metal-Ceramic beam is assumed to be given by a power-law type function. The non-linear strain-displacement relations in the von-Kármán sense are used to study the effect of geometric non-linearity. Also, four other representative averaging estimation methods, the linear rule, Mori-Tanaka, Self-Consistent and Wakashima-Tsukamoto schemes, by comparing with the power-law type function are also investigated. Temperature distribution through the thickness of the beams in thermal loadings is obtained by solving the one-dimensional heat transfer equation. Finally it is concluded that for Metal-Ceramic composites, these two theories result in identical static responses. Also the displacement field and equilibrium equations in the case of cylindrical bending of Metal-Ceramic plates are the same as those supposed in FSDBT2.

关键词： thermomechanical loading functionally graded beams monlinear analysis analytical solution

Prevalence and Types of Comorbidities in Pneumoconiosis—China,2018–2021

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China CDC weekly 2023年第38期5卷 837-843页

作者： Huanqiang Wang Xiangpei Lyu Dong Luo Huaping Dai department of occupational Respiratory Disease National Institute for Occupational Health and Poison ControlChinese Center for Disease Control and PreventionBeijingChina department of occupational hygiene and Poisoning Emergency The First Affiliated Hospital of Chongqing Medical and Pharmaceutical CollegeChongqingChina National Center for Respiratory Medicine State Key Laboratory of Respiratory Health and MultimorbidityNational Clinical Research Center for Respiratory DiseasesInstitute of Respiratory MedicineChinese Academy of Medical SciencesPeking Union Medical CollegeDepartment of Pulmonary and Critical Care MedicineChina-Japan Friendship HospitalBeijingChina.

Summary What is already known about this topic?Pneumoconiosis,recognized as one of the most detrimental occupational diseases in China,exhibits a multimorbidity profile due to a plethora of comorbidities and *** factors significantly influence the treatment outcomes,progression,prognosis,and overall quality of life of the afflicted patients.

关键词： morbid diseases prognosis