Consideration Of Manufacturing Cost Research Articles

Distributed and localized cooling with thermoelectrics

G. Jeffrey Snyder is a Professor of Materials Science and Engineering at Northwestern University in Evanston Illinois. His interests are focused on engineering of electronic and thermal properties, and he is well known for his work on thermoelectric materials. He has developed new methods of electron band structure engineering and microstructure engineering of thermal and electrical properties of complex materials. His interdisciplinary approach stems from his background in solid state chemistry at Cornell University and the Max Planck Institute for solid state research, applied physics at Stanford University, and thermoelectric materials and device engineering at NASA/Jet Propulsion Laboratory and California Institute of Technology (Caltech).

Material and manufacturing cost considerations for thermoelectrics

Interest in thermoelectrics for waste-heat recovery and localized cooling has flourished in recent years, but questions about cost and scalability remain unanswered. This work investigates the fabrication costs and coupled thermal and electrical transport factors that govern device efficiency and commercial feasibility of the most promising thermoelectric materials. For 30 bulk and thin film thermoelectric materials, we quantify the tradeoff between efficiency and cost considering electrical and thermal transport at the system level, raw material prices, system component costs, and estimated manufacturing costs. This work neglects the cost of heat, as appropriate for most waste-heat recovery applications, and applies a power generation cost metric in $/W and a cooling operating cost metric in $/kWh. The results indicate material cost sa re too high for typical thermoelectric power generation applications at mean temperatures below 135 1C. Above 275 1C, many bulk thermoelectric materials can achieve costs below $1/W. The major barrier to economical thermoelectric power generation at these higher temperatures results from system costs for heat exchangers and ceramic plates. For cooling applications, we find that several thermoelectric materials can be cost competitive and commercially promising.

Parallel machine match-up scheduling with manufacturing cost considerations

Many scheduling problems in practice involve rescheduling of disrupted schedules. In this study, we show that in contrast to fixed processing times, if we have the flexibility to control the processing times of the jobs, we can generate alternative reactive schedules considering the manufacturing cost implications in response to disruptions. We consider a non-identical parallel machining environment where processing times of the jobs are compressible at a certain manufacturing cost, which is a convex function of the compression on the processing time. In rescheduling it is highly desirable to catch up the original schedule as soon as possible by reassigning the jobs to the machines and compressing their processing times. On the other hand, one must also keep the manufacturing cost due to compression of the jobs low. Thus, one is faced with a tradeoff between match-up time and manufacturing cost criteria. We introduce alternative match-up scheduling problems for finding schedules on the efficient frontier of this time/cost tradeoff. We employ the recent advances in conic mixed-integer programming to model these problems effectively. We further provide a fast heuristic algorithm driven by dual prices of convex subproblems for generating approximate efficient schedules.

Product Line Design for Profit Maximization Using Common Parts, Features and Manufacturing Facilities

Designing products is an important managerial problem. In literature, we see this reflected essentially as engineering and marketing issues. However, this problem is tackled in isolation from each other and related production issues, resulting in products which require distinct parts, features and production facilities resulting in higher direct product and manufacturing costs than necessary. The problem of integrating product line design directly with manufacturing cost considerations have only recently received some attention, but the available models do not account for the advantages to be gained by the use of common facilities by products in the product line. In this paper, we formulate the product line design problem considering fixed and variable manufacturing costs and use of common parts, features and manufacturing facilities as an integer program. The objective of the model is to determine the optimal product line design to maximize total profit to the firm. To solve this NP-hard problem, we develop a fast and efficient heuristic based on beam search methods. Computational results on 270 simulated problems and an application derived from real data show that our heuristic identifies optimal (92% of the time) or near optimal solutions (within 99.7% of the optimal on average), is robust, and very fast (less than 7 Secs on a PC) for practical size problems.

Progress in optical waveguide process and materials

A brief up-to-date review of the main technologies currently used in the fabrication of optical waveguides and a report on recent process and material advances that affect fiber performance and/or cost are presented. The processes reviewed include vapor phase oxidation as well as direct-melt. Rapid technical progress continues to be made on numerous processes used to fabricate single-mode and multimode fibers. Process strengths are being verified and utilized, and many process problems minimized and eliminated. As fiber performance differences between processes become smaller, manufacturing cost considerations become increasingly important.