A two-level genetic algorithm for scheduling in assembly islands with fixed-position layouts

This paper focuses on the scheduling problem in assembly islands environment with fixed-position layouts. In such configuration, the product normally remains in one location for its entire manufacturing period while machines, materials and workers are moved to an assembly site called an assembly island. This production layout has some unique features such as moving assembly workers,tools and materials; limited space at assembly site; considerable distance between islands. The authors first give the definition and mathematical model for the scheduling problem and then propose a two-level genetic algorithm to obtain a near optimal solution to minimize the makespan. Experimental results show that this algorithm is effective. The performance analysis of the proposed algorithm indicates that it is more efficient in the airline or shipbuilding industry than in the machine or tool final assembly companies.     

考虑广告和产品结构的供应商管理库存系统的Nash博弈

假设文献[1]中的各个企业之间除了在库存管理方面进行合作外,还没有意识到在市场广告和供应链生产方面的合作,企业处于分别决策状态,每一个企业最大化其自身的利润。在给出考虑广告和产品结构的供应商管理库存系统的Nash非合作博弈模型,分析博弈结果和一些性质。最后给出一个算例说明本文的理论。     

A predominant role for the HLA class II region in the association of the MHC region with multiple sclerosis

Genetic susceptibility to multiple sclerosis is associated with genes of the major histocompatibility complex (MHC), particularly HLA-DRB1 and HLA-DQB1 (ref. 1). Both locus and allelic heterogeneity have been reported in this genomic region. To clarify whether HLA-DRB1 itself, nearby genes in the region encoding the MHC or combinations of these loci underlie susceptibility to multiple sclerosis, we genotyped 1,185 Canadian and Finnish families with multiple sclerosis (n = 4,203 individuals) with a high-density SNP panel spanning the genes encoding the MHC and flanking genomic regions. Strong associations in Canadian and Finnish samples were observed with blocks in the HLA class II genomic region (P < 4.9 x 10(-13) and P < 2.0 x 10(-16), respectively), but the strongest association was with HLA-DRB1 (P < 4.4 x 10(-17)). Conditioning on either HLA-DRB1 or the most significant HLA class II haplotype block found no additional block or SNP association independent of the HLA class II genomic region. This study therefore indicates that MHC-associated susceptibility to multiple sclerosis is determined by HLA class II alleles, their interactions and closely neighboring variants.     

Comparison of the effects of atropine sulfate and procaine hydrochloride on nerve conduction

Zusammenfassung Die lokalanästhetische Wirksamkeit des Atropinsulfats wurde mit der des Novokains mittels Messung der Kinetik des Nervenimpulsblocks am isolierten Nervus ischiadicus des Frosches verglichen. Die relative Wirksamkeit des Atropinsulfats ist weniger als 120.     

Methods for determining ploidy in amphibians: Nucleolar number and erythrocyte size

Summary Diploid and triploidXenopus can be easily and reliably distinguished by the size of their erythrocytes. This method has several advantages over other methods, such as counting metaphase chromosomes and counting nucleoli. One problem with the latter method is the reduction in cells with a full complement of nucleoli when regenerating tissue is used.Research supported by NIH grant EY 01662.     

Respiratory control in liver mitochondria of rats hosting the walker 256 carcinoma tumor.

The decrease in the respiratory control ratio of mitochondria is a first order process when these organelles are incubated in isotonic sucrose. Furthermore, the initial respiratory control ratios and the rates of loss in respiratory control in liver mitochondria from rats hosting the Walker 256 carcinoma are not significantly different form the same properties of mitochondria from untreated animals.