A mechanism for achieving a bound on execution performance of process group to limit CPU abuse

The secure OS has been the focus of several studies. However, CPU resources, which are important resources for executing a program, are not the object of access control in secure OS. For preventing the abuse of CPU resources, we had earlier proposed a new type of execution resource that controls the maximum CPU usage (Tabata et al. in Int. J. Smart Home 1(2):109–128, 2007). The previously proposed mechanism can control only one process at a time. Because most services involve multiple processes, the mechanism should control all the processes in each service. In this paper, we propose an improved mechanism that helps to achieve a bound on the execution performance of a process group in order to limit unnecessary processor usage. We report the results of an evaluation of our proposed mechanism.     

Identification of chemical detected in kiwi fruit during analysis for residual pesticide

An unknown peak was detected in a GC chromatogram of many kiwi fruit extracts during analysis for pesticide residues. It was identified by GC/MS as diphenyl 2-ethylhexyl phosphate (DPEHP), used as a plasticizer and flame retardant. The concentration of DPEHP was investigated in 15 samples of kiwi fruit, and it was detected at between 0.02 and 0.14 microgram/g in 10 of the samples. It might be due to migration of DPEHP into the fruit from the printed portion of the polyethylene terephthalate (PET) package.     

Applicability of non-analog Monte Carlo technique to reactor noise simulation

Reactor noise simulations have been performed with the analog Monte Carlo technique in the past. The applicability of the non-analog Monte Carlo technique, which uses “weighing” for the purpose of variance reduction, to reactor noise simulations has been discussed. The joint probability of a pair of counts and Feynman variance-to-mean ratio in the non-analog Monte Carlo technique are formulated for one-speed neutron random walk in an infinite homogeneous medium. Unlike the analog Monte Carlo technique, the fission-related correlation exists even for the number of fission neutrons ν = 1 because the neutron causing a fission survives and will contribute to subsequent detections. As a results, the joint probability and the variance-to-mean ratio has the same function of time as the analog Monte Carlo technique. The probability of an uncorrelated pair of counts for a coincidence detection within one detector is different from the analog Monte Carlo technique, which introduces an extra unknown parameter in Feynman-α method. In the two-detector system, the extra parameter does not arise and the conventional Feynman-α formula can be applied to non-analog Monte Carlo simulations. The formulations derived in this work are verified by the fact that the theoretical values agree well with the numerical results.     

Thermodynamic evaluation of surface tension of liquid metal‐oxygen systems

Thermodynamic equations have been derived to evaluate the surface tension of liquid metal‐oxygen systems. On the basis of these equations, the effect of the oxygen on the surface tension of liquid metals has been evaluated by using the fundamental information on the oxygen solubility in the metals, the surface tension and the molar volume of pure liquid metals and oxides. The calculated results from these equations agree with the literature values of the surface tension of liquid Fe‐O, Co‐O, Ni‐O, Cu‐O and Si‐O systems.     

Maximum efficiency control of a system composed of a piezoelectric transformer and cold cathode tube driven by inverter,and its characteristics

This paper concerns a control method in which cold cathode tube used for liquid crystal display, etc. is made to light at maximum efficiency. In the system composed of inverter, LC circuit, piezoelectric transformer, and cold cathode tube, tube current is controlled at the height of inverter output voltage, and the efficiency is controlled at the frequency. In this way, maximum efficiency control which does not depend on tube current is realized by carrying out tube current control and efficiency control separate. Maximum efficiency control method is deduced, after the characteristics of piezoelectric transformer and cold cathode tube are well examined, and the performance of the control has been confirmed by simulation and experiment. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 82– 93, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20567     

A calculation method of equivalent circuit constants with mutual leakage reactance on synchronous machine with damper winding

The mutual leakage reactance between the d‐axis damper and field windings is ignored in the conventional d‐axis equivalent circuit. It has been pointed out that the calculated value of the field transient current differs considerably from the measured value when this reactance is not taken into account. A method to determine this reactance has been reported previously, but this method has problems concerning measurement precision. The authors have previously presented a calculation method for equivalent circuits, adapting a DC decay testing method, using two synchronous machines of the same specifications (one with damper winding, the other without). Yet, this method is not practical because of the use of two machines. This paper presents a calculation method for equivalent circuit constants taking into account the mutual leakage reactance to accurately represent the field transient current using a single machine. The proposed method determines equivalent circuit constants by calculating the physically correct d‐axis transient reactance from the operational impedances when the field winding is shorted and when the field winding is shorted with an external resistance. The validity of the proposed method is demonstrated by comparing the measured values with the calculated values of field and armature currents at sudden three‐phase short‐circuit. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(2): 71–78, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20891     

PCR detection of Bacillus and Staphylococcus in various foods

A broad-range PCR assay for the detection of bacteria belonging to Bacillus and Staphylococcus genera was developed. Primers targeting the bacterial 16S rRNA gene were newly designed and used in a PCR assay. To determine the specificity of the assay, 81 different bacterial strains (of 50 genera), 2 fungi, 3 animals, and 4 plants were tested. Results were positive for every tested Bacillus, Staphylococcus, or Aerococcus strain. In addition, the result for Listeria grayi was positive with lower PCR product. For all other bacterial strains and eukaryotes tested, results were negative. Bacterial DNA was prepared with the use of achromopeptidase and Chelex 100 resin from culture after growth in brain heart infusion medium. To test the sensitivity of this PCR assay for Bacillus or Staphylococcus genus, either Bacillus cereus or Staphylococcus aureus was inoculated into various foods with undetectable levels of endogenous microbial contamination as an indicator. Inoculation of bacteria at 10 to 30 CFU/g of food was followed by a 5-h enrichment culture step after which the PCR assay allowed the detection of bacterial cells. When the inoculation (B. cereus or S. aureus) of 10 to 90 CFU/g into noodle foods containing endogenous microflora (10(3) to 10(5) CFU/g) was followed by a 6-h enrichment culture step, the PCR assay detected the bacteria. Including the enrichment culture step, the entire PCR detection process can be completed within 8.5 h.     

Identification of unknown peaks in foods during residual pesticide analysis

Four unknown peaks were detected in GC chromatograms during analysis of organophosphorus pesticide residues in foods. They were identified by using GC/MS as triethyl phosphate (TEP), tributyl phosphate (TBP), diphenyl 2-ethylhexyl phosphate (DPEHP) and N-ethyltoluenesulfoneamide (NETSA), which are used as plasticizers or flame retardants in food packaging. These chemical substances were detected in the range of tr. (below 0.01 microg/g) to 11 micro/g from 29 samples, and they were also detected in the packaging. It was supposed that they were transferred to the foods from the packaging. Furthermore, they were detected in some cereals and cereal products which contain fat and had been preserved for a long time.     

Simultaneous determination of N-methylcarbamate pesticides and their metabolites in agricultural products

We investigated the determination of N-methylcarbamate pesticides and their metabolites in agricultural products by HPLC with post-column fluorescence detection after clean-up with an SPE cartridge. The homogenate of agricultural products was extracted with acetone. The crude extract was partitioned between 5% sodium chloride solution and dichloromethane, and the dichloromethane layer was concentrated to dryness. The residue was dissolved with a mixture of acetone and n-hexane, and purified by using Supelclean ENVI-Carb SPE, Bond Elut Extraction Cartridge PSA and SAX in series with a mixture of acetone and n-hexane. N-Methylcarbamate pesticide was analyzed by HPLC with post-column reaction and fluoresce detection. N-Methylcarbamate pesticide in citrus fruits and various kinds of agricultural products could be analyzed accurately by the presented method. Recoveries of N-methylcarbamate pesticides added to several agricultural products at the level of 0.10 ppm were mostly in the range of 60-110%. The limit of detection was 0.005 ppm.