Integrated framework of risk evaluation and risk allocation with bounded data

This paper presents an integrated framework for risk evaluation and risk allocation with bounded data in a critical risk management. A risk evaluation framework using the Imprecise Data Envelopment Analysis (IDEA) method is proposed to be applied to operations of Korean Army helicopters. The risks pertaining to pilots, missions and helicopters are evaluated based on bounded data, and pilots are appropriately allocated to missions and helicopters using goal programming with bounded risk scores. Using bounded data, two risk allocation models are developed to be used with the expected value and lower/upper limit values, resulting in improved reliability of the solutions. Numerical experiments show reasonable solutions and valuable information for risk management.     

Existence of3He-vacancy bound states in4He crystals

Bound states and scattering resonances for a ³He-vacancy system in crystalline ⁴He are shown to exist. For realistic physical parameters the theory yields binding energies of 0.1 K. It is found that the bound states and scattering resonances tend to enhance the diffusion coefficient of ³He. The experimental consequences of this enhanced diffusion are discussed.     

Tables in text

Tables were inserted into a four page article, and subjects were asked to scan the text which was printed in a two-column or a single-column format. The single-column format was scanned significantly faster than the double-column layout, and there were marked reader preferences for the single-column layout.     

Improvement in the volume efficiency of multilayered ceramic capacitors (MLCCs)

An attempt was made to improve the conventional lamination process in the multilayered ceramic capacitors (MLCCs) fabrication by adapting a solvent treatment on the BaTiO₃ green sheets. During the lamination process, additional particle rearrangement in the BaTiO₃ green block was stimulated by solvent treatment. This rearrangement resulted in a more compact structure of the BaTiO₃ green sheets compared to that obtained through the conventional lamination process. The overall thickness of BaTiO₃/Ni/BaTiO₃ laminates was also reduced after solvent treatment. It is suggested that miniaturization in the fabrication of MLCCs can be improved by adapting a solvent treatment during the lamination process.     

A miniature UWB planar monopole antenna with 5-GHz band-rejection filter and the time-domain characteristics

A planar monopole antenna with a staircase shape and small volume (25/spl times/26/spl times/1 mm/sup 3/) is proposed in this paper. With the use of a half-bowtie radiating element, the staircase-shape, and a modified ground plane structure, the proposed antenna has a very wide impedance bandwidth measured at about 11.6 GHz (2.9-14.5 GHz, bandwidth ratio about 1:5) below VSWR 2 including the WLAN band notched in the vicinity of 5 GHz. An omnidirectional radiation pattern is obtained. The group delay which is an indication of linearity between two proposed antennas is less than 1 ns. The electrical characteristics in terms of frequency and time domains and physical ones of the proposed antenna make it attractive for use in ultrawideband (UWB) systems.     

Operation, system architectures, and physical Layer design considerations of distributed MAC protocols for UWB

Impulse-based ultra wideband (I-UWB) is an attractive radio technology for large ad hoc and sensor networks due to its robustness to harmful multipath effects, sub-centimeter ranging ability, simple hardware, and low radiated power. To scale to large sizes, networks often implement distributed medium access control (MAC) protocols. However, most MAC protocols for I-UWB are centralized, and they target small wireless personal area networks and cellular networks. We propose three distributed MAC protocols suitable for I-UWB. Two multichannel protocols, called multichannel pulse sense multiple access (M-PSMA) and multichannel ALOHA achieve high aggregate throughput. A busy-signal protocol, called busy-signal multiple access (BSMA), reduces the energy wasted from re-transmitted packets. This paper describes the three protocols in terms of the protocol's operation, the supporting system architecture, and the I-UWB physical layer. Physical layer simulations confirm the feasibility of implementing the proposed systems and also provide parameters for network simulations. Network simulations show that the throughput of M-PSMA exceeds that of a centralized time-division multiple-access protocol and that the energy efficiency of BSMA far surpasses that of other distributed protocols.     

G.729A+B语音编解码在新一代定点DSPs上的实现

文章介绍了ITU-TG．729A算法与ITU-TG．729B算法配合使用的语音编解码方案，并讨论了其在TI公司最新一代定点数字信号处理器(DSPs)TMS320C6416上实现的关键技术。G．729A是G.729编码器的简化版本，G．729B是带VAD(活动话音检测)的静音压缩算法。两者结合可以有效地降低码率，同时保持很好的合成语音质量。     

Molecular dynamic study for nanopatterning using atomic force microscopy

The atomic force microscopy (AFM)-based nanolithographic technique is currently used to directly machine material surfaces and fabricate nanocomponents for microelectromechanical systems (MEMS) devices. In the current study, three-dimensional molecular dynamic (MD) simulations with potentials based on the Morse function were performed to evaluate the effect of crystallographic factors and process variables on the nanodeformation characteristics of the nanolithography processing of monocrystalline copper. Moreover, the effects of process variables (tool shape, cutting speed, and ploughing depth) on the nanostructural pattern are investigated. The simulation results revealed that the crystal orientation and ploughing direction had a significant influence on varying the forces (cutting force, thrust force, and width-direction force); the nature of the nanodeformation ahead of the tool; and the surface quality of the machined material.     

The LabMatrix system

The LabMatrix^™ is a prototyping system designed to give the user a practical and versatile platform for testing microfluidic applications in the fields of health care and life sciences. The LabMatrix^™ system consists of a microfluidic breadboard and cover that align and secure a series of specially designed LabMatrix^™ microfluidic chips. Chips are easily arranged and rearranged into a user-defined fluidic network. The LabMatrix^™ system is designed with maximum flexibility in mind, providing the user with a means to prototype a wide range of microfluidic applications in a short period.     

安钢高强板AH60的生产实践

本文论述了高强度低合金钢板AH60的试制过程，结合产品技术要求和生产实际设计合理的成分体系和工艺路线。