The product cycling problem under increasing yield rates

We investigate the product cycling problem (also known as the common cycle scheduling problem) when there are economies of scale due to increasing yield rates. Increasing yield rates are characteristic of production processes in which the percentage of acceptable parts increases with the duration of the production run, usually owing to adjustments made during the initial portion of the production run. We develop a solution procedure that is optimal for a wide range of production cost functions under very mild conditions. We then compare optimal solutions with those obtained from the commonly used 'fixed-plus-linear' approximation of costs. Computational results suggest that the 'fixed-plus-linear' approximation generally performs well, but may result in substantial errors under certain extreme conditions.     

The Organization of Product Development

This paper develops a critical perspective on the theory underlyingcontemporary product development practice. It contrasts whatis today the dominant approach to design and product development,an approach that is analytical and problem-oriented, with analternative approach that is interpretative and process-oriented.The interpretative approach views product development as enteringinto an ongoing process in which people are already engaged.It sees the interactions between the different communities involvedin product development as a set of ongoing conversations. Itsuggests the need for a set of conceptual tools for managingthis process which are quite distinct from those associatedwith the analytical approach.     

Effect of ZrO2 Inclusions on the Sinterability of Al2O3

The sinterability of Al₂O₃/ZrO₂ composite powder compacts containing 2 and 10 vol% ZrO₂ was compared to the sinterability of their single-phase constituents through constant-heating-rate experiments. The ZrO₂ inclusion phase delayed the initiation of bulk shrinkage and the temperature of maximum strain rate by 100°C. The ZrO₂ inclusion phase also significantly inhibited grain growth. These results, discussed with regard to the thermodynamics of pore disappearance, suggest that phenomena inhibiting grain growth may also inhibit densification.     

EFFECT OF PBAN ON PHEROMONE PRODUCTION BY MATED <Emphasis Type="Italic">Heliothis virescens</Emphasis> AND <Emphasis Type="Italic">Heliothis subflexa</Emphasis> FEMALES

Mated female Heliothis virescens and H. subflexa were induced to produce sex pheromone during the photophase by injection of pheromone biosynthesis activating neuropeptide (PBAN). When injected with 1 pmol Hez-PBAN, the total amount of pheromone that could be extracted from glands of mated females during the photophase was similar to that extracted from virgin females in the scotophase. The PBAN-induced profile of pheromone components was compared between mated, PBAN-injected females and virgin females during spring and fall. Virgin females exhibited some differences in the relative composition of the pheromone blend between spring and fall, but no such temporal differences were detected in PBAN-injected, mated females. Because the temporal variation in pheromone blend composition was greater for virgin females than for PBAN-injected females, PBAN can be used to determine a females native pheromone phenotype. This procedure has the advantages that pheromone glands can be extracted during the photophase, from mated females that have already oviposited.     

Model for Ion-Exchanged Waveguides in Glass

An analytical model describing refractive index profiles in ion-exchanged glass waveguides is presented. Polarizability, volume, and stress-state changes are accounted for. Index distribution is given in terms of known or measurable physical parameters. Model predictions compare favorably with experimental results of field-assisted ion-exchanged waveguides fabricated in 7740 borosilicate glass. Experimental characterization of the index changes includes prism coupling, microprobe, and photoelastic measurements.     

On the Fourier transform of sequency limited signals with applications to delta modulation and medicine†

It is the binary nature of the Walsh basis functions that make the Walsh transform a potentially useful signal processing tool. Unlike the FFT, which produces a database in the easily interpreted frequency domain, a Walsh data base resides in the obscure sequency domain. Using a fast Walsh algorithm, an N-point transform can, however, be computed more rapidly than a FFT using a similar computer architecture. Even though the sequency space has been shown to be useful in coding and picture processing applications, the aperiodic behaviour of its basis functions make it. unsuitable for many traditional signal-processing problems. It would be desirable, for example, to be able to relate the computationally efficient Walsh spectra to the intuitively pleasing Fourier spectra. This work will address that problem and present new results.     

Resource settings have a major influence on the outcome of maintenance hemodialysis patients in South India

Chronic kidney disease is reaching epidemic proportions and the number of patients on renal replacement therapy (RRT) is increasing worldwide and also in developing countries. To meet the challenge of providing RRT, a few charity organizations provide hemodialysis units for underprivileged patients, as the private hospitals are unaffordable for the majority. There is a paucity of information on the outcome of dialysis in these patients. Here, we describe the outcome of hemodialysis patients comparing the middle‐ and upper‐class income group with the lower class income group. A retrospective analysis was carried out in 558 CKD patients initiated on maintenance hemodialysis in two different dialysis facilities. Group A (n=247) included those who belonged to the lowermost socioeconomic status and were undergoing dialysis in two nonprofit, charity (TANKER)‐run dialysis units, and Group B (n=311) was undergoing dialysis in a nonprofit hospital setting where no subsidy was given. Those patients of a low socioeconomic status, especially those who are diabetics, have a higher death rate (Group A‐38.1%, Group B‐4.2%) and loss to follow‐up (Group A‐25.9%, Group B‐0.3%) compared with those who are in the middle‐ and high‐income group. Higher EPO use and hence higher hemoglobin levels (Group A‐6.4±1.2, Group B‐8.9±1.5 P<0.001) were observed in those who were in the middle and the higher income group. Lower serum phosphorus level was observed in the low‐socioeconomic group (Group A‐4.7±1.5, Group B‐5.5±1.9, P<0.001). Patients belonging to the middle and higher socioeconomic group undergo more transplantations compared with the lower socioeconomic group (Group A‐2.4%, Group B‐65.6%).     

Ranking multicritena fuzzy alternatives in the decision-maker's preference subspace

This paper offers a new procedure for ranking multicritena fuzzy alternatives when the decision-maker subscribes to the notion of ‘the larger, the better’. For each alternative a joint membership function captures possible interactions among ratings for each criterion. The ranking procedure first orthogonally projects the joint membership functions from the multicritena decision space to the one-dimensional preference subspace, and then the fuzzy projections are ranked in that subspace. A method for generating joint membership functions is introduced, and a numerical example is presented.