Bounds to optimal burn-in and optimal work size

2005 ◽  
Vol 21 (3) ◽  
pp. 227-239 ◽  
Author(s):  
Ji Hwan Cha ◽  
Jie Mi
Keyword(s):  
Work Size

Forklift Hydraulic System Simulation Based on ADAMS

2012 ◽  
Vol 424-425 ◽  
pp. 598-602 ◽  
Author(s):  
You Min Wang ◽  
Chun Zhao ◽  
Jian Hua Zhang
Keyword(s):  
Hydraulic System ◽  
Production Cost ◽  
Control Function ◽  
Three Dimensional ◽  
Improve Design ◽  
Kinematics Simulation ◽  
Simulation Based ◽  
Motion Speed ◽  
Work Size ◽  
Control Functional

In order to improve design performance, shorten development cycles, reduce production cost, we design and research the forklift hydraulic system, developed forklift hydraulic system diagram. Forklift virtual prototype’s 3-D solid modeling is designed by Pro / E three-dimensional software, and imported into the ADAMS environment. Add constraints and drivers exert the control function separately to the tilting cylinder and lifting cylinder, carry on the kinematics simulation. Through the analysis to the compound motion actuation control functional arrangement、the compound motion speed graph、the gate’s tilt angle graph、the tilting cylinder stress graph and the lifting cylinder stress graph, he simulation result indicated: each cylinder design is reasonable, the movement without interference，the reasonable work scope satisfied to the work size request

Age-replacement policy and optimal work size

2002 ◽  
Vol 39 (2) ◽  
pp. 296-311 ◽  
Author(s):  
Jie Mi
Keyword(s):  
Time Distribution ◽  
Failure Time ◽  
Repair Time ◽  
Replacement Policy ◽  
Average Amount ◽  
Failure Time Distribution ◽  
Long Run ◽  
Random Failure ◽  
Age Replacement ◽  
Work Size

Suppose that there is a sequence of programs or jobs that are scheduled to be executed one after another on a computer. A program may terminate its execution because of the failure of the computer, which will obliterate all work the computer has accomplished, and the program has to be run all over again. Hence, it is common to save the work just completed after the computer has been working for a certain amount of time, say y units. It is assumed that it takes a certain time to perform a save. During the saving process, the computer is still subject to random failure. No matter when the computer failure occurs, it is assumed that the computer will be repaired completely and the repair time will be negligible. If saving is successful, then the computer will continue working from the end of the last saved work; if the computer fails during the saving process, then only unsaved work needs to be repeated. This paper discusses the optimal work size y under which the long-run average amount of work saved is maximized. In particular, the case of an exponential failure time distribution is studied in detail. The properties of the optimal age-replacement policy are also derived when the work size y is fixed.

Reaction Anisotropy and Size Resolved Oxidation Kinetics of Zinc Nanocrystals

2009 ◽  
Vol 1201 ◽  
Author(s):  
Xiaofei Ma ◽  
Michael R. Zachariah
Keyword(s):  
Oxidation Kinetics ◽  
Sampling Error ◽  
Oxidation Mechanism ◽  
Size Dependent ◽  
Anisotropy Effect ◽  
Shrinking Core ◽  
Mobility Method ◽  
Intrinsic Reactivity ◽  
Work Size ◽  
Kinetics Of

AbstractIn this work, size-classified substrate-free Zn nanocrystals (NCs) are prepared and investigated for their oxidation kinetics using an in-flight tandem ion-mobility method. The first mobility characterization size selects the NCs, while the second mobility characterization measures changes in mass resulting from a controlled oxidation of the NCs. This method allows for a direct measurement of mass change of individual particles and thus enables us to explore the intrinsic reactivity of NCs while minimizing the sampling error introduced by mass and heat transfer. Two reaction regimes were observed for Zn NC oxidation. A shrinking core model is used to extract the size-dependent oxidation activation energies. We also observed a strong anisotropy effect in the oxidation process as imaged by electron microscopy. An oxidation mechanism is proposed that qualitatively explains the oxidation anisotropy and its relationship to the surface energy of the Zn NCs.

Age-replacement policy and optimal work size

2002 ◽  
Vol 39 (02) ◽  
pp. 296-311 ◽  
Author(s):  
Jie Mi
Keyword(s):  
Time Distribution ◽  
Failure Time ◽  
Repair Time ◽  
Replacement Policy ◽  
Average Amount ◽  
Failure Time Distribution ◽  
Long Run ◽  
Random Failure ◽  
Age Replacement ◽  
Work Size

Suppose that there is a sequence of programs or jobs that are scheduled to be executed one after another on a computer. A program may terminate its execution because of the failure of the computer, which will obliterate all work the computer has accomplished, and the program has to be run all over again. Hence, it is common to save the work just completed after the computer has been working for a certain amount of time, say y units. It is assumed that it takes a certain time to perform a save. During the saving process, the computer is still subject to random failure. No matter when the computer failure occurs, it is assumed that the computer will be repaired completely and the repair time will be negligible. If saving is successful, then the computer will continue working from the end of the last saved work; if the computer fails during the saving process, then only unsaved work needs to be repeated. This paper discusses the optimal work size y under which the long-run average amount of work saved is maximized. In particular, the case of an exponential failure time distribution is studied in detail. The properties of the optimal age-replacement policy are also derived when the work size y is fixed.

Optimized Design of Single Link Flexible Manipulator

2011 ◽  
Author(s):  
S. Mahto ◽  
U. S. Dixit
Keyword(s):  
Flexible Manipulator ◽  
Optimized Design ◽  
Fundamental Frequencies ◽  
Numerical Experimentation ◽  
Single Link ◽  
Sequential Quadratic Programming Method ◽  
Flexible Robotic Manipulator ◽  
Quadratic Programming Method ◽  
Work Size ◽  
Euler Bernoulli Beam

In this work, size optimization of a single link flexible robotic manipulator is carried out by considering the link as an Euler-Bernoulli beam. Finite element method is used for obtaining the natural frequencies and time response. Sequential quadratic programming method is used to maximize fundamental frequencies of the manipulator for different designs. A comparative study of the optimized designs is carried out to find out their suitability for real world situation. Based on the numerical experimentation, suggestion for formulating optimization problem for varying tip loads is provided.

A note on the upper bound for the optimal work size

2004 ◽  
Vol 41 (01) ◽  
pp. 277-280
Author(s):  
Ji Hwan Cha
Keyword(s):  
Upper Bound ◽  
Optimization Problem ◽  
Replacement Policy ◽  
Two Dimensional ◽  
Age Replacement ◽  
Work Size ◽  
Dimensional Optimization

Mi (2002) recently considered a two-dimensional optimization problem for the optimal age-replacement policy and the optimal work size. In order to find (y ∗,T ∗), Mi (2002) found the optimal age-replacement policy T ∗(y) for each fixed work size y, and then searched for the optimal work size y ∗. When applying this approach, for each fixed work size y, Mi (2002) obtained the bounds for T ∗(y). However, no bound for the optimal work size y ∗ was derived. In this note, the results on the upper bound for the optimal work size y ∗ are given.

Framework Study for Agile Software Development Via Scrum and Kanban

2020 ◽  
Vol 17 (04) ◽  
pp. 2030002
Author(s):  
Wael Zayat ◽  
Ozlem Senvar
Keyword(s):  
Visual Signals ◽  
Agile Methodologies ◽  
Project Environment ◽  
Complex Projects ◽  
Development Teams ◽  
Project Complexity ◽  
Output Factors ◽  
System Improvement ◽  
Agile Software ◽  
Work Size

This paper provides a systematic comparison between two well-known Agile methodologies: Scrum, which is a framework of doing projects by allocating tasks into small stages called sprints, and Kanban, which is a scheduling system to manage the flow of work by means of visual signals. In this regard, both methodologies were reviewed to explore similarities and differences between them. Then, a focus group survey was performed to specify the preferable methodology for product development according to various parameters in the project environment including project complexity, level of uncertainty, and work size with consideration of output factors like quality, productivity, and delivery. Results show the flexibility of both methodologies in approaching Agile objectives, where Scrum emphasizes on the corporation of the customer and development teams with a focus on particular skills such as planning, organization, presentation, and reviewing which makes it ideal for new and complex projects where a regular involvement of the customer is required, whereas Kanban is more operative in continuous-flow environments with a steady approach toward a system improvement.

Size distribution analysis of wear particles in the transmission system of mining equipment

2017 ◽  
Vol 232 (8) ◽  
pp. 921-926 ◽  
Author(s):  
Ashwani Kumar ◽  
Subrata K Ghosh
Keyword(s):  
Size Distribution ◽  
Wear Debris ◽  
Wear Particle ◽  
Transmission System ◽  
Distribution Analysis ◽  
Wear Particles ◽  
Mining Equipment ◽  
Debris Particles ◽  
Shape Characteristics ◽  
Work Size

In this work, size and shape characteristics of wear debris particles present in the transmission system of heavy earth moving machines have been analysed. Four oil samples were collected from the dumper transmission system for wear debris analysis. Ferrogram maker has been used to seperate the wear particles present in oil samples and to capture the image of particles. The statistical results confirm that the Weibull probability distribution function has more potential to fit the wear particle size distribution accurately than the Rayleigh model in case of heavy earth moving machines. Results show the initiation of abnormal wears and suggested that condition-based maintenance is necessary.

A note on the upper bound for the optimal work size

2004 ◽  
Vol 41 (1) ◽  
pp. 277-280 ◽  
Author(s):  
Ji Hwan Cha
Keyword(s):  
Upper Bound ◽  
Optimization Problem ◽  
Replacement Policy ◽  
Two Dimensional ◽  
Age Replacement ◽  
Work Size ◽  
Dimensional Optimization

Mi (2002) recently considered a two-dimensional optimization problem for the optimal age-replacement policy and the optimal work size. In order to find (y∗,T∗), Mi (2002) found the optimal age-replacement policy T∗(y) for each fixed work size y, and then searched for the optimal work size y∗. When applying this approach, for each fixed work size y, Mi (2002) obtained the bounds for T∗(y). However, no bound for the optimal work size y∗ was derived. In this note, the results on the upper bound for the optimal work size y∗ are given.

The Organization of lawyers' Work: Size, Intensity, and Co-Practice of the Fields of Law

1979 ◽  
Vol 4 (2) ◽  
pp. 217-246 ◽  
Author(s):  
Edward O. Laumann ◽  
John P. Heinz
Keyword(s):  
Cross Section ◽  
Legal Doctrine ◽  
Or Groups ◽  
The Law ◽  
Using Data ◽  
Work Size ◽  
Corporate Clients ◽  
Total Effort

Using data from personal interviews with 777 Chicago lawyers, constituting a random cross section of the urban bar, the authors estimate the relative volumes of effort devoted to each of several fields of law, analyze the degree to which practitioners specialize in fields or groups of fields, and examine the patterns of co-practice of the fields. They find that the total effort of the Chicago bar is about evenly divided between work for corporate clients and work for individual clients. They also suggest that, while relatively few lawyers are highly specialized to a particular doctrinal area of the law, most are specialized to the service of the needs of a particular type of client. Exploring possible implications of their findings, the authors speculate that lawyers who are specialized to clients rather than to substantive fields may lack the incentive to devote their resources to the rationalization of legal doctrine.

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