Effect of Mo contents on corrosion behaviors of welded duplex stainless steel

The corrosion behaviour and change of the phase fraction in welded 24Cr Duplex stainless steel was investigated for different chemical composition ranges of Mo contents. Filler metal was produced by fixing the contents of Cr, Ni, N, and Mn while adjusting the Mo content to 0.5, 1.4, 2.5, 3.5 wt%. The δ-ferrite fraction was observed to increase as the content of Mo increased. A polarisation test conducted in a salt solution, indicated the pitting corrosion potential increased continuously to 3.5 wt% Mo, while the corrosion potential changed most between 0.5 and 1.41 wt% Mo. The location of the pitting corrosion in 0.5 wt% Mo steel was randomly distributed, but it occurred selectively at the grain boundary between the γ- and δ-ferrite phases in 1.4, 2.5 and 3.5 wt% Mo steel. Energy dispersive X-ray spectroscopy mapping analysis showed that areas deficient in Cr, Mo, and Ni occurred around the grain boundary of the γ- and δ-ferrite phases. Non-metallic inclusions are thought to act as initiation points for the pitting corrosion that occurs in the salt solution initially as a result of the potential difference between the matrix structure and the incoherent inclusions.     

An approach to feature‐based software construction for enhancing maintainability

While the way we build software affects significantly its maintenance in terms of the effort and cost, the experience level of the maintainer in a software acquirers' organization is also one of concern. In this context, often the maintainer is the user of the system. Unfortunately, it is quite possible to lose the trustworthiness of the software due to the inexperience of the maintainer, especially when the maintainer is without the help of the original developers. One remedy for providing security against the effects of the maintainer's software modifications is to restrict the access to software parts (modules) relative to the experience level of the maintainers. For such a remedy to be successful, the software should be constructed in such a way that its parts under maintenance affect others as little as possible. We propose an approach to software construction aligning the dependencies among software parts in one direction so that they are allocated to maintainers based on their experience level. Our approach decomposes the software into parts based on functionality and orders the parts by essentiality, which indicates how difficult it is to change each part. Then, we align the dependencies in such a way that the less essential functionality is dependent on the more essential functionality. Consequently, any modification on less essential functionality does not affect the essential functionalities. To demonstrate the feasibility of our proposed approach, we applied it to a military application and found that the constructed software enables us to confine maintainers' activity within a limited working area, and thus the software is safer against maintainers' modification. Copyright © 2006 John Wiley & Sons, Ltd.     

Analysis of pricing strategies for e-business companies providing information goods and services

In this paper, we introduce a mathematical model to analyze pricing and service quality strategies for e-business companies providing information services to customers. The basic strategy considered in this paper is that a monopolistic e-business company provides free services to try to earn a profit by developing premium goods or services to market created by their free goods or services. It is a kind of versioning strategy where lower quality versions of information goods are provided free. And a direct network effect was also considered. And we tried to find the profit maximizing strategies for monopolistic e-business companies. As a result, the optimal quality and price for the premium goods or services can be obtained at the same level of the intensity of the direct network effect. And the exact term related with the network externality is derived and insights are demonstrated through numerical explorations.     

Structural evolution in Fe ion implanted Si upon thermal annealing

We have performed high-dose Fe ion implantation into Si and characterized ion-beam-induced microstructures as well as annealing-induced ones using transmission electron microscopy (TEM) and grazing-incidence X-ray diffraction (GIXRD). Single crystals of Si(1 0 0) substrate were irradiated at 623 K with 120 keV Fe⁺ ions to a fluence of 4 × 10¹⁷ cm⁻². The irradiated samples were then annealed in a vacuum furnace at temperatures ranging from 773 K to 1073 K. Cross-sectional TEM observations and GIXRD measurements revealed that a layered structure is formed in the as-implanted specimen with ε-FeSi, β-FeSi₂ and damaged Si, as component layers. A continuous β-FeSi₂ layer was formed on the topmost layer of the Si substrate after thermal annealing.     

Structural changes of SiC under electron-beam irradiation: Temperature dependence

Electron-beam-irradiation effects on silicon carbide (SiC) was investigated as a function of the irradiated temperatures. Single crystalline 6H-SiC was irradiated with 300 kV electrons at temperatures ranging from −170 to 250 °C. It was found that amorphous SiC is induced at −170 °C and room temperature, while crystalline Si is formed at 250 °C with a high electron fluence. It is considered that preferential knock-on displacement of C atoms and damage recovery play an important role in the formation of the amorphous SiC and crystalline Si.     

Operation of 1550-nm electroabsorption-Modulated laser at 40/spl deg/C for 10-gb/s, 40-km transmission

Semicooled operation at 40/spl deg/C of electroabsorptive modulator integrated laser (EML) for intermediate reach communication has been demonstrated. Reproducible operation at the elevated temperature was achieved through a device parameter optimized based on the temperature dependence of the dc characteristics of EML and a design of multi-quantum-well structure providing both relevant output power and high-frequency bandwidth at 40/spl deg/C. Good eye pattern and near zero chirp with the average power over 0 dBm are obtained at 40/spl deg/C, with an estimated lifetime over 20 years.     

Control of an object with parallel surfaces by a pair of finger robots without object sensing

This paper proposes a method for controlling an object with parallel surfaces in a horizontal plane by a pair of finger robots. The control method can achieve stable grasping, relative orientation control, and relative position control of the grasped object. The control inputs require neither any object parameters nor any object sensing, such as tactile sensors, force sensors, or visual sensors. The control inputs are also quite simple and do not need to solve either inverse kinematics or inverse dynamics. The stability of the closed-loop system is proved, and simulation and experimental results validate the control method.     

Visualization method for customer targeting using customer map

An important issue in customer-oriented marketing area is target selection which enables the determination of potential customers. In this paper, we suggest a novel customer targeting method: customer map for a service industry. The customer map is the visualization method for customer targeting. It depicts value distribution across customer needs and customer characteristics. To develop the customer map, we integrate numerous customer data from various data sources, perform data analyses using data mining techniques, and finally visualize the information derived by the former analyses. The customer map helps decision makers to build customer-oriented strategy under the unified goal of customer targeting. It also affords to monitor and perceive real time state and the change of customer value distribution based on their information without preconception. We apply the customer map to a credit card company, build web-based prototype system for the customer map and acquire managerial implications from this study.     

Dynamics and Stability 3-Dimensional Object under of Blind Grasping of a Non-holonomic Constraints

A mathematical model expressing the motion of a pair of multi-DOF robot fingers with hemi-spherical ends, grasping a 3-D rigid object with parallel fiat surfaces, is derived, together with non-holonomic constraints. By referring to the fact that humans grasp an object in the form of precision prehension, dynamically and stably by opposable forces, between the thumb and another finger （index or middle finger）, a simple control signal constructed from finger-thumb opposition is proposed, and shown to realize stable grasping in a dynamic sense without using object information or external sensing （this is called ＂blind grasp＂ in this paper）. The stability of grasping with force/torque balance under non-holonomic constraints is analyzed on the basis of a new concept named ＂stability on a manifold＂. Preliminary simulation results are shown to verify the validity of the theoretical results.