Technology adoption, product design, and process change: a casestudy in the machine tool industry

The experience of the machine tool industry suggests that many manufacturing organizations are reexamining their manufacturing processes and technologies in response both to the need to gain flexibility and efficiency in their operations and to a rising awareness of resource costs and environmental concerns. The adoption of new technologies, especially technologies which reduce material requirements and waste, will require organizations to rethink how they design and manufacture their products. Changes in product and process design will affect the technologies and operations of numerous organizations along the production supply chain. Through a case study of the machine tool industry, this paper explores the impacts of the adoption of forming technology instead of conventional cutting technology on the production of selected metal parts. This paper is organized in three parts. In the first part, the costs, technical advantages, and environmental compatibility of cutting and forming technologies are profiled. Forming technology is shown to provide substantial savings in raw material, energy and waste disposal over cutting technology for a class of high-volume metal parts. The second part explores the changes in part and process design which occur when forming technology is adopted for parts which have traditionally been made by cutting. The costs of these design changes must be balanced against the environmental savings. The third part explores the extent to which changes due to the adoption of new forming technology ripple along the production supply chain to suppliers and other upstream organizations     

Improving software maintenance by learning from the past: a casestudy

Although it is common to view software maintenance as an activity that is distinct from software development, it is often true that the development it is often true that the development of novel products is mixed in with the evolution of existing products. Examples are families of similar applications, such as communications processors, that share considerable functionality, and a large scale information system that acts as a base for new tasks. In these situations, the maintenance process involves the adaptation of previous experience to new requirements. The author explores this type of environment, first by examining the software process, and then by relating the key activities to maintenance. An information system case study is used to illustrate how the experience of the past can be structured to facilitate future modifications     

On the probability of success in a routing process

Lee's path search mechanism has been identified as a percolation process and the probability of a successful search is obtained analytically.     

Observations on the measurement of R&D productivity: a casestudy

Recent concerns over national and corporate competitiveness have stimulated a renewed interest in the measurement of R&D productivity. However, the complexity of measurement problems in R&D organizations has resulted in a situation where there is a scarcity of generally accepted techniques. The authors review the major measurement issues connected with R&D productivity and presents the results of a case study to develop a R&D productivity measurement system. They describe the process of designing such a system for a high-tech product-development organization, and also provide a reduced list of ten R*D productivity indicators for ongoing monitoring purposes     

Operationalizing the concept of concurrent engineering: a casestudy from the US auto industry

This paper presents the results of case study research conducted at a major US automotive firm. Four waves of qualitative data were collected to identify the organizational and technological changes needed to implement concurrent engineering practices. The desire to cut product development time was the driving factor in a strategy designed to boost sales and market share. The company was successful in shortening concept-to-market time by over one year on its first newly designed vehicle, primarily through the use of product-focused, cross-functional platform teams which permitted the early integration of manufacturing personnel into product and process development. While technology played an important role in this transformation, organizational, and human resource changes were the greatest enablers     

Noise temperature and gain loss due to paints and primers: a casestudy of DSN antennas

In achieving high performance for reflector antennas, it has been noted that it is essential to carefully assess the roles of surface paints and primers. A thorough literature search has revealed that not much has been reported on this very important engineering-implementation topic. It is one of the main objectives of this feature article to provide a detailed study on the effects of paints and primers on reflector-antenna performance. In particular, as a case study, this paper presents excess-noise-temperature and added-gain loss data at 32 GHz for various combinations of paints and primers currently being studied for use on DSN (Deep Space Network) antenna reflector surfaces. It is shown that 500FHR6 acrylic urethane-based paint has the lowest excess-noise-temperature contribution. Previously, it has been recommended that this paint be used for all new DSN beam-waveguide antennas being constructed, and for all those 34-m and 70-m antennas with reflector surfaces that need repainting. The results, methodologies, and observations presented in this article are also applicable to other reflector-antenna configurations     

Evaluation of SPOT and TM data for forest stratification: a casestudy for small-size poplar stands

The value of SPOT and TM data for stratification of poplar stands prior to volume inventory is assessed. The stratification is based upon the poplar development stage, which is determined by canopy closure and tree height. The effect of development stage and type of understorey vegetation on the spectral radiance of poplar stands is analyzed throughout the vegetation period. The optimal acquisition date(s) and spectral range(s) and the most suited classification approach for discrimination of poplar development stages are determined. Satellite images recorded during the full growing season are preferred for poplar stand stratification according to development stage. In this period the interfering effect of the understory vegetation is minimal in proportion to the effect of the poplar stand development stage. Young poplar stands can accurately be classified as long as the appropriate spectral range of an image registered during the full growing period is selected. The discrimination between young and other popular development stages is accurate enough for use in a stratification prior to volume inventory     

Efficiency improvement of the traveling-wave interaction process

Experimental evidence that conventionally designed, uniform-period traveling-wave amplifiers are potentially highly efficient devices is presented. Experiments with a traveling-wave re-entrant cavity tube and with a two-helix tube show that substantial improvement is possible when the RF energy of the so-called beam of a saturated traveling-wave tube is used. Tests reported here on the two-helix tube realized efficiencies greater than 43 percent.     

An approximation for the loss probability in a multiserver queue fed by a shifting level process

A shifting level (SL) process is useful to traffic modeling because it is very easy to match the stationary distribution and autocorrelation function of the SL process with those of measured real traffics. Especially, SL processes have been used to traffic modeling for VBR video traffics reflecting the long range dependence and the scene structure. We give an approximation for the loss probability in a multiserver queue fed by a SL process. Numerical examples show that our approximation is very accurate.     

A bound on the probability that a Gaussian process exceeds a given function (Corresp.)

An upper bound is calculated for the probability that a mean-zero Gaussian random process remains above a specified signal throughout a prescribed interval of time.     

A decision support system using judgmental modeling: a case ofR&D in the pharmaceutical industry

The development of a computerized decision support system for R&D project ranking, monitoring and control in the pharmaceutical industry is described. Using a series of techniques based on a judgmental modeling approach, an overall system has been developed that covers several different aspects of the whole decision making process. Illustrative examples are given to show how the components of the model are used in practice, indicating their place in the overall management process. The results provide evidence supporting the value of such models which help reduce ambiguity by using structured approaches     

Cycle-accurate energy measurement and characterization with a casestudy of the ARM7TDMI [microprocessors]

Energy characterization is the basis for high-level energy reduction. Measurement-based characterization is accurate and independent of model availability and is thus suitable for commercial off-the-shelf (COTS) components, but conventional measurement equipment has serious limitations in this context. We introduce a new technique for the energy characterization of a microprocessor using a cycle-accurate energy measurement system based on charge transfer which is robust to spiky noise and is able to collect a range of energy consumption profiles in real time. It measures the energy variation of the CPU core by changing the instruction-level energy-sensitive factors such as opcodes (operations), instruction fetch addresses, register numbers, register values, data fetch addresses and immediate operand values at each pipeline stage. Using the ARM7TDMI RISC processor as a case study, we observe that the energy contributions of most instruction-level energy-sensitive factors are orthogonal to the operations. We are able to characterize the energy variation, preserving all the effects of the energy-sensitive factors for various software methods of energy reduction. We also demonstrate applications of our measurement and characterization techniques     

高能激光与光电二极管热作用过程的温度分布

采用脉宽为毫秒的高能脉冲激光与PIN结光电二极管进行相互作用,建立了包含热源项的导热方程,并考虑了热物性参数随温度变化的情况.利用有限元方法计算了材料到达熔点前材料轴向和径向温度随时问和位置的变化规律,同时对相关物理过程进行了讨论.进而研究了热物性参量的变化对材料开始熔化时间的影响.结果表明,热传导将直接影响着整个相互作用过程,而材料热物性参数的变化亦将影响材料的熔化时间.     

Managing the Magnetic Properties of NiCo/C Nanocomposites

Russian Microelectronics - The creation of new types of radio-absorbing materials (RAMs) is relevant due to the intensive development of microwave radio electronic devices, their increasing power,...     

A new heuristic method redundancy optimization in a consecutive-k-out-of-n:F system by fuzzy probability

In this paper it is presented heuristic method and its modification for solution of the redundancy optimization problem by fuzzy failure probabilities. This method is considered for consecutive-k-out-of-n:F system due to simplified expression for reliability importance of components. Method is based on the fuzzification and on the fuzziness importance of failure probabilities.     

Second generation I/SUP 2/L/MTL: a 20 ns process/structure

A high performance, second generation I/SUP 2/L/MTL gate for digital LSI applications with TTL compatibility has successfully been designed, characterized, and demonstrated fully functional over a wide current range and the military temperature range of -55 to 125/spl deg/C. Performance is measured using an in-line five-collector gate having one end injector. The gate performed with the following characteristics at 100 /spl mu/A injector current: /spl beta//SUB U//SUP eff//spl ges/4 for all collectors at 25/spl deg/C and /spl ges/2.5 at -55/spl deg/C, /spl alpha//SUB rec///spl alpha//SUB F//spl cong/0.58 and /spl tau/~/SUB d/=18-20 ns from -55 to 125/spl deg/C, and a speed-power product of 1.4 pJ at 25/spl deg/C. At low injector currents, a constant speed-power product of 0.36 pJ at 25/spl deg/ was obtained.     

Bounds for the probability of failure resulting fromstress/strength interference

The failure probability in static stress-strength models is determined by the interference region. Methods have been devised which determine the bounds on this unreliability based only upon the independent probabilities in this region; no distribution identification or knowledge of the means or variances is required. Unfortunately, empirical evidence demonstrates that existing methods can provide inaccurate bounds on the unreliability. An alternate method is developed which bounds the unreliability with certainty     

Bounds on a probability for the heavy tailed distribution and the probability of deficient decoding in sequential decoding

Although sequential decoding of convolutional codes gives a very small decoding error probability, the overall reliability is limited by the probability P_G of deficient decoding, the term introduced by Jelinek to refer to decoding failures caused mainly by buffer overflow. The number of computational efforts in sequential decoding has the Pareto distribution and it is this "heavy tailed" distribution that characterizes P_G. The heavy tailed distribution appears in many fields and buffer overflow is a typical example of the behaviors in which the heavy tailed distribution plays an important role. In this paper, we give a new bound on a probability in the tail of the heavy tailed distribution and, using the bound, prove the long-standing conjecture on P_G, that is, P_G ap constanttimes1/(sigma^rhoN^rho-1) for a large speed factor sigma of the decoder and for a large receive buffer size N whenever the coding rate R and rho satisfy E(rho)=rhoR for 0 les rho les 1