Boron distribution in a low-alloy steel

Boron distribution in a low-alloy steel (15B26:0.25C-0.29Cr-0.03Ti-0.028Al-0.0016B) has been characterized employing Fission Track Etching (FTE) method. The characteristics of boron distribution with variation of cooling rate after austenitization and through case-hardened depth after carburization were analyzed. Hardenability of 15B26 steel was also evaluated through Jominy-end-quench test and the results are as follows: It was observed that, in austenitized 15B26 steel, boron was distributed uniformly over the whole area of specimen with a little segregation along the austenite grain boundaries at higher cooling rates and boron precipitates were formed in the intergranular as well as transgranular regions at lower cooling rates. Jominy equivalents (HRC 35) of 15B26 steel were fairly increased between the Jominy temperatures of 820°C and 850°C, which might result from the increase of the amount of soluble boron in austenite due to the dissolution of borocarbides between 820°C and 850°C. In carburized 15B26 steel, the different through thickness features of boron distribution from the carburized surface were found; coarse nodular boron precipitates up to the depth of 150 μm; uniform distribution of dissolved boron between 150~650 μm; and segregation of boron atoms along grain boundaries in the regions deeper than 650 μm.     

Characteristics of ZnO thin film deposited on various metal bottom electrodes

ZnO films for electronic applications were deposited by radio-frequency (rf) sputtering onto various metal bottom electrodes (Pt/Ti, W, Ni) to investigate such structural properties as crystallinity and surface morphology. The crystallinity, surface morphology and composition of the as-deposited films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rutherford back-scattering spectrometry (RBS), respectively. The preferred orientation and surface morphologies were strongly influenced by the type of bottom electrodes. The ZnO films with (200) texturing deposited on Pt/Ti/SiO₂/Si showed a smoother and smaller grain size than those deposited on W and Ni. The ZnO films on Pt and W electrodes exhibited compressive residual stress. This article is based on a presentation made in the 2002 Korea-US symposium on the “Phase Transformations of Nano-Materials”, organized as a special program of the 2002 Annual Meeting of the Korean Institute of Metals and Materials, held at Yonsei University, Seoul, Korea on October 25–26, 2002.     

Zr－Nb系合金耐蚀性能研究

结合核动力堆用燃料包壳对锆合金耐蚀性能的要求，大范围考察了Ｎｂ含量为０．５％，１．０％，２．６％（ｗｔ％）的Ｚｒ—Ｎｂ二元合金及含Ｃｒ、Ｍｏ、Ｓｎ、Ｂｉ、Ｆｅ、Ｃｅ和Ｓｉ的Ｚｒ－１Ｎｂ及多元合金，共１７种成分的Ｚｒ－Ｎｂ系合金在４００℃，１０．３ＭＰａ水蒸汽中的长期腐蚀规律（达１８２天）。在腐蚀转折前，Ｚｒ－Ｎｂ系合金的腐蚀动力学曲线均近似于抛物线规律，而在转折之后存在与线性规律偏离现象。长期腐蚀增重的分析说明：通过合理的多元合金化，即增加或降低Ｎｂ含量，并主加Ｆｅ、Ｂｉ、Ｓｎ和Ｎｉ而辅加少量的Ｃｒ、Ｍｏ、Ｔｅ和Ｓｉ，Ｚｒ－１Ｎｂ合金的耐蚀性大有潜力可挖。     

Simulations of the dielectric constant of bonding materials and field emission properties of CNT cathodes

The effect of the dielectric constant (k) of bonding materials in a screen-printed carbon nanotube (CNT) cathode on the field enhancement factor was investigated for high-efficiency CNT cathodes using the ANSYS software. The values obtained by a simulation study were compared to the experimental results obtained for screen-printed CNT cathodes. The field enhancement factor increased as the dielectric constant decreased, reaching a maximum value at a dielectric constant of 1, the value for a vacuum. The findings indicate that the larger sheet resistance of the bonding materials, after the firing process, can be attributed to the larger emission current of the CNT cathode. From these results, it was concluded that the best bonding materials for screen-printed CNT cathodes should have a low dielectric constant and a high sheet resistance. This finding can be used as criteria for selecting bonding materials for use in CNT pastes for highly efficient CNT cathodes.     

Effect of change management capability in real-time environment: an information orientation perspective in supply chain management

Supply chain management (SCM) is an important strategic tool that requires careful planning and management. While the availability of real-time information is a critical aspect of an SCM system, it possesses a potential to disrupt supply chain participants. Thus, the success of an SCM system hinges on how well participants deal with changes taking place in a real-time environment. This study adopts the concept of the real-time enterprise to understand the role of change management on SCM performance based on the concept of the information orientation. The study empirically validated the role of change management on SCM performance.     

Effective pedestrian detection using deformable part model based on human model

Recently, pedestrian detection systems have become an important technology in the development of the advanced driver assistance system (ADAS) for the autonomous car. The histogram of oriented gradients (HOG) is currently the most basic algorithm for detecting pedestrians, but it treats the entire body of the pedestrian as one single feature. In other words, if the entire body of the pedestrian is not visible, the detection rate under HOG decreases markedly. To solve this problem, we propose a detection system using a deformable part model (DPM) that divides the pedestrian data into two parts using a latent support vector machine (SVM)-based machine-learning technique. Experimental results show that our approach achieves better performance in a detection system than the existing method. In practice, there are many occlusions in the environment in front of the vehicle. For example, the surrounding transport facilities, such as a car or another obstacle, can occlude a pedestrian. These occlusions can increase the false detection rate and cause difficulties during the detection process. Our proposed method uses a different approach and can easily be applied in real-world scenarios, regardless of occlusions.

     

Formulating the template ILP consistency problem as a constraint satisfaction problem

Inductive Logic Programming (ILP) deals with the problem of finding a hypothesis covering positive examples and excluding negative examples, where both hypotheses and examples are expressed in first-order logic. In this paper we employ constraint satisfaction techniques to model and solve a problem known as template ILP consistency, which assumes that the structure of a hypothesis is known and the task is to find unification of the contained variables. In particular, we present a constraint model with index variables accompanied by a Boolean model to strengthen inference and hence improve efficiency. The efficiency of models is demonstrated experimentally.     

Imperfect premise matching based fuzzy control with passive constraints for discrete time-delay multiplicative noised stochastic nonlinear systems

This paper investigates a fuzzy controller design method for discrete-time nonlinear stochastic time-delay systems which are presented by the Takagi-Sugeno (T-S) fuzzy model with multiplicative noises. Utilizing the proposed design method, the fuzzy controller can be carried out via not only state feedback scheme but also output feedback scheme. Both of them are accomplished by the concept of imperfect premise matching (IPM). For discussing the stabilization problem, the Lyapunov-Krasovskii function and passivity theory are applied to derive the sufficient conditions. Moreover, the discrete Jensen inequality is employed to decrease the conservatism of the proposed method. Finally, a numerical example for the control of a nonlinear time-delay pendulum system is provided to show the effectiveness and usefulness of the proposed design method.     

Range image denoising using a constrained local Gaussian model for 3D object query service in the smart space

A position and direction is a fundamental information for U-Business as an anywhere service. A mobile device camera image can increase an accuracy of the positioning, and a range image provides significant information in an occlusion scene. U-Business service queries the information with the range image for a precision position or a target object. We present a method for smoothing heavy noisy surfaces acquired by mobile 3D imaging devices to obtain the stable curvature. The smoothing is performed in a way that finds centers of probability distributions, which maximizes the likelihood of observed points with smooth constraints. The smooth constraints are derived from the unit tangent vector equality. This provides a way of obtaining smooth surfaces and stable curvatures. We achieve the smoothing by solving the regularized linear system. The unit tangent vector equality involves consideration of geometric symmetry, and it minimizes the variation of differential values that are a factor of curvatures. The proposed algorithm has two apparent advantages. The first thing is that the surfaces in a scene with various signals-to-noise ratio are smoothed, and then they can earn suitable curvatures. The second is that the proposed method works on heavy noisy surfaces, for example, a stereo camera image. Experiments on range images demonstrate that the proposed method yields the smooth surfaces from the input with various signals-to-noise ratio and the stable curvatures obtained from the smooth surfaces.