A multi-machine labor assignment for variable operator service times

This paper presents an approach to the multi-machine labor assignment problem, where a single operator can serve a number of semi-automatic machines simultaneously in a synchronous service discipline. The operator service times are assumed to be normally distributed, while the machine processing times are deterministic. This paper provides optimum or near-optimum solutions for the assignment at a minimum combined cost of idle times for both labor and machines. Feasibility checks are incorporated in the solution procedure to meet the due date and maximum operator travel distance restrictions. A computer program is developed to implement the assignment procedure for large size problems.     

Measurement of impedance transformation on practical dipoles

The measured input impedance of a practical dipole antenna is shown to be related to the theoretical input impedance of a delta-gap cylindrical dipole through a bilinear transformation. In order to determine the three complex constants which specify the transformation, the impedance of a dipole in front of a ground plane is measured and compared with the theoretical impedance. The comparison is performed by a curve-fitting procedure for bilinear transformation on a complex plane. The same measurement yields also the receiving efficiency of the antenna and its feeding network. Experiments show that the input impedance of a practical folded dipole, incorporating a balun transformer, may be predicted with an accuracy of better than four percent.     

Complex Permittivity and Permeability of Co$_2$U (Ba$_4$Co$_2$Fe$_36$O$_60$) Hexaferrite Bulk and Composite Thick Films at Radio and Microwave Frequencies

We measured dielectric, magnetic, and microwave properties of Co ₂U hexaferrite (Ba₄Co₂Fe₃₆O ₆₀) polycrystalline bulk and composite thick film samples, and studied the effect of annealing temperature on phase formation and microstructure. We synthesized the bulk samples from a precursor prepared by the citrate method. The values of dielectric constant at radio frequencies (50 Hz-1 MHz) of the bulk Co₂U12 sample sintered at 1200degC are much higher, and the resistivities are lower, compared to M-type barium hexaferrites. Coercivity is also low, having a value of 5 G for the Co₂U12 sample, whereas the saturation magnetization value is 59 emu/g, which is comparable to that of M-type hexaferrites. We also measured the complex permittivity and permeability for Co₂U12 samples at microwave frequencies and found the values high compared to M-type barium hexaferrite at these frequencies. Thick composite films were prepared from a ferrite-polymer mix, and all the above properties were studied for these films. We observed that these thick films have lower values of dielectric and magnetic parameters both at low and microwave frequencies. We measured microwave-absorbing properties for the ferrite-polymer sample (ferrite to polymer ratio 70/30) which showed a maximum reflection loss of -37.5 dB at 11.5 GHz for the 3.5-mm-thick sample     

The belief bias effect is aptly named: A reply to Klauer and Kellen (2011).

In “Assessing the Belief Bias Effect With ROCs: It's a Response Bias Effect,” Dube, Rotello, and Heit (see record 2010-14834-005) examined the form of receiver operating characteristic (ROC) curves for reasoning and the effects of belief bias on measurement indices that differ in whether they imply a curved or linear ROC function. We concluded that the ROC data are in fact curved and that analyses using statistics that assume a linear ROC are likely to produce Type I errors. Importantly, we showed that the interaction between logic and belief that has inspired much of the theoretical work on belief bias is in fact an error stemming from inappropriate reliance on a contrast (hit rate?false alarm rate) that implies linear ROCs. Dube et al. advanced a new model of belief bias, which, in light of their data, is currently the only plausible account of the effect. Klauer and Kellen (2011) disputed these conclusions, largely on the basis of speculation about the data collection method used by Dube et al. to construct the ROCs. New data and model-based analyses are presented that refute the speculations made by Klauer and Kellen. We also show that new modeling results presented by Klauer and Kellen actually support the conclusions advanced by Dube et al. Together, these data show that the methods used by Dube et al. are valid and that the belief bias effect is simply a response bias effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Model-driven optimal resource scaling in cloud

Cloud computing offers the flexibility to dynamically size the infrastructure in response to changes in workload demand. While both horizontal scaling and vertical scaling of infrastructure are supported by major cloud providers, these scaling options differ significantly in terms of their cost, provisioning time, and their impact on workload performance. Importantly, the efficacy of horizontal and vertical scaling critically depends on the workload characteristics, such as the workload’s parallelizability and its core scalability. In today’s cloud systems, the scaling decision is left to the users, requiring them to fully understand the trade-offs associated with the different scaling options. In this paper, we present our solution for optimizing the resource scaling of cloud deployments via implementation in OpenStack. The key component of our solution is the modeling engine that characterizes the workload and then quantitatively evaluates different scaling options for that workload. Our modeling engine leverages Amdahl’s Law to model service timescaling in scale-up environments and queueing-theoretic concepts to model performance scaling in scale-out environments. We further employ Kalman filtering to account for inaccuracies in the model-based methodology and to dynamically track changes in the workload and cloud environment.     

Potentiometric methods for determining boron, hydrogen cyanide and hydrogen chloride compounds and their use in controlling the quality of manufacturing and natural environments

The authors present basic science for, elaborate and set as methodic recommendations some potentiometric methods using ion-selective electrodes. Efficiency of those methods was proved in experiments with such substances as boron compounds, hydrogen cyanide, hydrogen chloride. High sensitivity, selectivity, accuracy and rapidity of the methods with handy technique make the facilities available for analysis of air at workplace, ambient atmosphere, water and biologic materials, detecting wide range of concentrations. Practical application of the methods enabled to specify measures to preserve health of workers and general population, helped in hygienic evaluation of work conditions in composition materials production, high-temperature soldering, optic glass industry.     

Genetic heterogeneity in human T-cell leukemia/lymphoma virus type II

DNA from the peripheral blood mononuclear cells of 17 different individuals infected with human T-cell lymphoma/leukemia virus type II (HTLV-II) was successfully amplified by the polymerase chain reaction (PCR) with the primer pair SK110/SK111. This primer pair is conserved among the pol genes of all primate T-cell lymphoma viruses (PTLV) and flanks a 140-bp fragment of DNA which, when used in comparative analyses, reflects the relative degree of diversity among PTLV genomes. Cloning, sequencing, and phylogenetic comparisons of these amplified 140-bp pol fragments indicated that there are at least two distinct genetic substrains of HTLV-II in the Western Hemisphere. These data were confirmed for selected isolates by performing PCR, cloning, and sequencing with to 10 additional primer pair-probe sets specific for different regions throughout the PTLV genome. HTLV-II isolates from Seminole, Guaymi, and Tobas Indians belong in the new substrain of HTLV-II, while the prototype MoT isolate defines the original substrain. There was greater diversity among HTLV-II New World strains than among HTLV-I New World strains. In fact, the heterogeneity among HTLV-II strains from the Western Hemisphere was similar to that observed in HTLV-I and simian T-cell lymphoma/leukemia virus type I isolates from around the world, including Japan, Africa, and Papua New Guinea. Given these geographic and anthropological considerations and assuming similar mutation rates and selective forces among the PTLV, these data suggest either that HTLV-II has existed for a long time in the indigenous Amerindian population or that HTLV-II isolates introduced into the New World were more heterogeneous than the HTLV-I strains introduced into the New World.     

Evaluation of pulsed-field gel electrophoresis as a typing system for Candida rugosa: comparison of karyotype and restriction fragment length polymorphisms

Nosocomial infections with Candida species have emerged as an increasingly important cause of morbidity and mortality in intensive care units. Ten Candida rugosa isolates from a previously documented cluster of C. rugosa infections in one hospital (nine burn unit isolates and one isolate from another hospital ward) and eight C. rugosa isolates recovered in a referral fungus testing laboratory (comparison isolates) from distinct geographic areas were investigated by molecular techniques. Isolates were from multiple anatomic sites. Pulsed-field gel electrophoresis (PFGE) of whole-cell DNA was performed with the 18 C. rugosa isolates as a marker of strain identity. The PFGE karyotypes of the C. rugosa isolates were demonstrated from four to seven chromosome bands. Karyotyping revealed the same PFGE pattern for the nine outbreak isolates from the burn unit, confirming clonal strain transmission. The isolate from the other hospital ward had a distinct karyotype. Distinct PFGE karyotype patterns were demonstrated for the eight comparison isolates. Restriction fragment length polymorphisms (RFLP) generated from whole-cell DNA digested with SfiI demonstrated the same RFLP pattern among outbreak isolates. Among comparison isolates, karyotyping distinguished some isolates that were indistinguishable by RFLP patterns. Karyotyping by PFGE appears to be the most useful molecular typing tool for discrimination among strains of C. rugosa and will be a useful marker for evaluating the epidemiology of future C. rugosa infections.