软件外包中分包商选择的优化模型及算法

软件企业常作为发包方将软件项目的某些部分外包给其他企业来转移风险,与多方合作共同承担软件项目的开发,但分包方选择不当同样会给企业带来巨大的风险。为规避分包商选择失误带来的风险,提出了分包商选择的多目标规划模型,该模型以发包方企业成本最小和风险最小为目标对多个软件分包商进行选择。针对模型非线性复杂化整数规划的特点,设计了混合粒子群算法(GA-PSO)对模型进行求解。通过对一个算例的测试,证明了该模型及算法的有效性和可行性。     

A Fail-safe Logic Operator Using an Insulated Planar Transformer

A fail-safe logic circuit must switch the output signal to the logical value “0” when an operation circuit fails. A transformer has such favorable characteristics for fail-safe logic circuits as only the magnetic flux change is transmitted and a superposition of magnetic flux is realized. Thus those characteristics arc applied to a failsafe logic operator. A new fail-safe logic operator using an insulated planar transformer was developed for a fail-safe majority operation and a fail-safe interlocking. In this paper, the principle, structure, design and fundamental characteristics of the new fail-safe logic operator are described.     

Design for 2-D error feedback networks with identical coefficient sets

In realization of recursive digital filters with fixed point arithmetic, an error caused by roundoff arises. It is known that the level of the roundoff noise of an IIR filter tends to be high when the poles are close to the unit circle. Error feedback (EF) is an effective method to reduce the roundoff noise. It is desirable to design an EF network using as few parameters as possible in order to keep computational costs low. In this paper, we propose a method for designing a 2D EF network with identical coefficient sets. That is, the EF coefficients are divided into several subsets such that all the elements within each set have the same absolute value. In order to optimize the coefficient sets, we propose an algorithm by using the genetic algorithm. In the numerical example, we demonstrate the effectiveness of the proposed method.     

Structural analysis of β-form poly(p-xylyene) starting from a high-resolution image

The crystal structure of β-form poly(p-xylylene) is analysed starting from a high-resolution image of a single crystal of this polymer. The high-resolution image corresponding to the projection of molecules onto the ab-plane along the chain axis shows clearly the mutual position of each molecule in a unit cell. The molecules are aligned wavily in the direction along the a-axis and the rough positions of their centres in a unit cell can be determined from the image. The refinement of the structure is carried out by the usual least-squares method using the intensities of electron and X-ray diffractions. The space group of the β-form is trigonal, P3, and the lattice dimensions are a=2.052 nm, c=0.655 nm and γ=120°. The unit cell contains 16 molecules and one of them is considered to occupy statistically one of three equivalent orientations so as to satisfy the P3 symmetry.     

Irrigation

This paper provides an overview of the main features of irrigation in Japan, and the issues it raises, rather than an exhaustive survey of the subject. The authors’ remarks concentrate on irrigation for rice cultivation, since irrigation for non‐paddy crops is not widely developed and claims a very minor share of the country's water resources. The main components of the water requirements of rice irrigation are identified, and then the composition and functions of farmers’ irrigation associations, or more correctly ‘land improvement districts’, are described.     

A Barium-Titanate-Ceramics Capacitive-Type EEG Electrode

A capacitive-type electrode using barium titanate ceramics is described. This electrode is not affected by the polarization potential. Because its surface is chemically inactive and mechanically strong, its noise voltage is minimum from the beginning of its installation. This device is especially suitable for EEG recording.     

Electron transfer reactions of glucose oxidase at Au111 electrodes modified with phenothiazine derivatives

The catalytic reaction of glucose oxidase (GOx) mediated by 3-(10-phenothiazyl)propionic acid (PT-PA) and phenothiazine-labeled poly(ethylene oxide) (PT-PEO1000) that are covalently bonded to Au(111) electrodes has been investigated. The PT-PA and PT-PEO1000 are reacted with 2-aminoethanethiol (AET), followed by the formation of a self-assembled monolayer (SAM) onto the Au surface. The PT group immobilized on the SAM of AET acts as an effective mediator for the electron transfer (ET) between the electrode and the FAD center of freely diffusing GOx in solution. The ET rate constant estimated from the catalytic current using a newly derived equation is larger by 1 order of magnitude for the PT-PA-modified system (1.1 x 10(5) dm(3) mol(-1) s(-1)) than for the PT-PEO1000 system (1.4 x 10(4) dm(3) mol(-1) s(-1)). The order of the magnitude of the ET rate constant clearly contrasts with the GOx hybrid systems that we previously investigated (Anal. Chem. 2003, 75, 910-917), in which the presence of the PEO spacer enhances the ET reaction rate. The reduction in the apparent PT concentration at the electrode interface due to the high mobility of the PEO chain, leading to low efficiency in the formation of an enzyme-mediator complex, is a possible reason for the lower mediation ability of PT-PEO1000 than that of PT-PA for the ET between the FAD group and PT(+) immobilized on the electrode. Inhibition of the penetration of GOx molecules into the monolayer and of the accessibility of some part of PT groups to GOx molecules could also be reasons for the lower mediation ability of PT-PEO1000 thickly modified on the electrode.     

New Class of High-TC Diluted Ferromagnetic Semiconductors Based on CaO without Transition Metal Elements

We propose new-type ferromagnetic semiconductors based on CaO and K₂S without any transition metal elements. These materials show transparent and half-metallic ferromagnetism if the deep-impurity-band width (W) induced by doping of C, N, Si, or Ge impurities, and the electron-correlation energy (U) satisfy the Stoners condition of highly correlated electron system (U>W). Based on our first-principles calculations, we demonstrate that these materials satisfy the Stoners condition, and could be new candidates for transparent and half-metallic DMSs.