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21.
Planned Leadtimes For Serial Production Systems 总被引:1,自引:0,他引:1
Candace Arai Yano 《IIE Transactions》1987,19(3):300-307
We investigate the problem of setting planned leadtimes in serial production systems when the actual leadtimes are stochastic. The objective is to minimize the sum of inventory holding costs, rescheduling costs arising from tardiness at intermediate stages of production, and tardiness of delivery to the customer.
A single-pass algorithm is developed which finds optimal solutions. The analytical models underlying the algorithm and extensive computational experience indicate that it is never optimal to have planned leadtimes of zero when there are rescheduling costs at intermediate stages of production. This also implies that unconditional immediate dispatching is not optimal under these conditions. 相似文献
A single-pass algorithm is developed which finds optimal solutions. The analytical models underlying the algorithm and extensive computational experience indicate that it is never optimal to have planned leadtimes of zero when there are rescheduling costs at intermediate stages of production. This also implies that unconditional immediate dispatching is not optimal under these conditions. 相似文献
22.
When the minimum-time trajectory of a manipulator along a geometrically prescribed path is planned taking into consideration the manipulator's dynamics and actuator's torque limits, at least one of the joints should be at the torque limit. The execution of such a trajectory by a conventional feedback control scheme results in torque saturation. Consequently, the tracking error cannot be suppressed and the manipulator may deviate from the desired path. In this paper, the author's propose a feedback control method for path tracking which takes the torque saturation into account. Based on the desired path, a coordinate system called path coordinates is defined. The path coordinates are composed of the component along the path and the components normal to the path. The equation of motion is described in terms of the path coordinates. Control of the components normal to the path is given priority in order to keep the motion of the manipulator on the path. Simulations of a two-degree-of-freedom manipulator show the effectiveness of this method 相似文献
23.
S Arai M Tsuji SJ Kim K Nakada R Kirisawa M Ohta C Ishihara 《Canadian Metallurgical Quarterly》1998,60(12):1321-1327
Exploring the antigenic and genetic diversities of Babesia ovata, we obtained several field isolates from grazing cattle in the Okushiri island, Japan. Parasite isolation was greatly facilitated by using bovine red blood cell-substituted SCID mice (Bo-RBC-SCID mice), into which the blood samples of the cattle were inoculated. Isolates from different individuals within a herd of cattle were compared in immunoblot analysis with an anti-B. ovata serum and also in Southern blot analysis with a probe for the small subunit ribosomal RNA gene. In both analyses, the isolates exhibited banding patterns that were significantly different from each other. We were also able to obtain a series of parasite isolates from a single cow in different seasons of a nine months period, including winter when active vector ticks were not in the field environment. Different seasonal isolates showed different banding patterns in both immunoblot and Southern blot analyses. By contrast, these analyses detected little difference among the parasites that had been passed various times in Bo-RBC-SCID mice, where no specific immune responses should be generated. These results indicate that individual animals within a herd of cattle were infected with antigenically and genetically diversified populations of B. ovata, and that the parasites could persistently infect a single animal with dynamic change in their predominant subpopulations. 相似文献
24.
In the first half of the paper, various types of processing pertaining to a polygon, using the 4×4 determinant theories are explained along with a new containment test algorithm of a point in a polygon. In the latter half of the paper, a general-purpose geometric processor, the POLYGON ENGINE, is presented which can deal with various types of interference problems, such as Boolean operations in solid modelling, hidden line and surface eliminations, ray tracing and so on. It is, a successor of the TRIANGLE PROCESSOR and is also based upon the 4×4 determinant theories [4–6]. While the TRIANGLE PROCESSOR processes a triangulated polygon on a triangle-by-triangle basis, the POLYGON ENGINE can treat a polygon without triangulation. The latter is expected to be more functional, more efficient and easier to use. 相似文献
25.
Susumu Onaka Masaharu Kato T. Mori 《Metallurgical and Materials Transactions A》1986,17(11):1949-1953
Steady-state sliding of grain boundaries is discussed by taking into account the change in the potential energy of an applied
stress, when the sliding occurs by diffusional accommodation. The present analysis enables us to derive the sliding rates
at boundaries of various shapes in a simple manner without knowing local stress fields. Sliding rate of a boundary containing
second phase particles is also derived by similar calculations. The results are compared with previous calculations by other
investigators, and it is found that the resultant expressions for the sliding rates are essentially identical to those derived
from more complex analyses. 相似文献
26.
Takanori Inoue Keiichiro Hoashi Koichi Eguchi Hiromichi Arai 《Journal of Materials Science》1993,28(6):1532-1536
The electrode characteristics of perovskite-type oxides, La0.6Sr0.4CoO3 and La0.6Sr0.4MnO3, on ceria-based oxide and stabilized zirconia were analysed by the a.c. impedance method. The ionic conductivities of the electrolyte and electrode conductivities from the a.c. impedance analysis agreed with those obtained from the current interruption and d.c. four-probe methods. Two semicircles from the charge transfer and diffusion processes appeared as the electrode resistance. The relative contribution of these two processes to the overall electrode resistance strongly depended on the microstructure of the electrode. The electrode microstructure could be controlled by the dispersion medium used for the electrode slurry. The La0.6Sr0.4MnO3 electrode coated with n-butyl acetate slurry exhibited the smallest electrode resistance. 相似文献
27.
JAK-STAT signaling pathways are known to play an essential role in the specific activation of interferon-inducible genes. Many cytokines interacting with the cytokine receptor superfamily also appear to activate these pathways. Recent evidence indicates that JAKs play an essential role(s) in cytokine receptor signaling, including both specific pathways linked to STATs and general pathways regulating cell growth and functions. 相似文献
28.
Our procedure of real-zero conversion uses a spectrum-reversal technique to convert the information of a bandlimited signal to real zeros. We conducted a simple reconstruction experiment and showed that our proposed method is essentially equivalent to the conventional technique of sine-wave crossings 相似文献
29.
Di-, tri-, tetra-, penta- and hexasaccharides were formed during the hydrolysis of lactose by transgalactosylation reaction of Aspergillus oryzae β-galactosidase. In this study the isolation and characterization of the major constituents of tri-, tetra- and pentasaccharides are described. The structure elucidation of 3 tri-, 2 tetra- and 1 pentasaccharides was carried out by methylation analysis, mass spectrometry and 13C-nmr spectrometry. The trisaccharides are , and . Tetrasaccharides are and [or . Pentasaccharide is . 相似文献
30.
Makoto Kasu Rangaiya Rao Susumu Noda Akio Sasaki 《Journal of Electronic Materials》1991,20(9):691-693
Properties of theDX centers in Al0.5Ga0.5As bulk alloy (b-AL), (AlAs)2 (GaSa)2 ordered superlattice (o-SL) and (AlAs)
m
(GaAs)
n
disordered superlattice (d-SL) (m = 1, 2, 3,n = 1, 2, 3) with the same macroscopic composition were measured and compared. By deconvolution of deep level transient spectroscopy
(DLTS) spectrum due to theDX center, we have found a decrease in the number of separate peaks in DLTS spectrum in an intentionally atomic ordered arrangement.
Visiting Scholar of the Japan Society for the Promotion of Science. On leave from Department of Electrical Engineering, San
Jose State University, San Jose, California 95192-0084, USA. 相似文献