New class of 2D code and encoders for multiplexed measuring systems

A new class of 2D codes and encoders built by the self-supporting method, using the direct product of ternary pseudorandom sequences that consist of −1, 0, +1 and have an ideal periodic autocorrelation function is proposed and studied. Expressions are derived for the optimality criteria used in experimental design with allowance for the statistical characteristics of the distribution of the radiation sources and noise superimposed on the measurements. The point spread functions presented characterize the topographical properties of the multiplexed measuring system with an encoder based on a ternary sequence. Translated from Izmeritel'naya Tekhnika, No. 10, pp. 49–53, October, 1997.     

Generalized GMW Quadriphase Sequences Satisfying the Welch Bound with Equality

This paper gives new families of quadriphase sequences obtained from large linear complexity sequences over Z ₄ by making use of generalized permutation monomials over Galois rings. The construction of these sequences can be seen as a generalization of the binary GMW sequence construction and hence they are referred to as GGMW sequences over Z ₄. The GGMW families satisfy the Welch bound on inner products with equality and it is shown that the root mean square of all the crosscorrelations and out-of-phase autocorrelations (θ_rms), is approximately equal to the quantity ; L being the period of the sequences. However, θ_max, the maximum magnitude of periodic crosscorrelation and out-of-phase autocorrelation, deviates from the optimal value of . Computer results suggest that the number of crosscorrelation values which deviate from the optimal value of is small. The weight structure of these sequences is the same as those of m-sequences over Z ₄. The linear complexity (LC) of the sequences is computed using a generalized Blahuts theorem on the LC of sequences over Z ₄. Received: January 18, 1999; revised version: October 20, 1999     

Dynamics and ‘normal stress’ evaluation of dilute suspensions of periodically forced prolate spheroids in a quiescent Newtonian fluid at low Reynolds numbers

The problem of determining the force acting on a particle in a fluid where the motion of the fluid and the particle is given has been considered in some detail in the literature. In this work, we propose an example of a new class of problems where, the fluid is quiescent and the effect of an external periodic force on the motion of the particle is determined at low non-zero Reynolds numbers. We present an analysis of the dynamics of dilute suspensions of periodically forced prolate spheroids in a quiescent Newtonian fluid at low Reynolds numbers including the effects of both convective and unsteady inertia. The inclusion of both forms of inertia leads to a nonlinear integro — differential equation which is solved numerically for the velocity and displacement of the individual particle. We show that a ‘normal stress’ like parameter can be evaluated using standard techniques of Batchelor. Hence this system allows for an experimentally accessible measurable macroscopic parameter, analogous to the ‘normal stress’, which can be related to the dynamics of individual particles. We note that this ‘normal stress’ arises from the internal fluctuations induced by the periodic force. In addition, a preliminary analysis leading to a possible application of separating particles by shape is presented. We feel that our results show possibilities of being technologically important since the ‘normal stress’ depends strongly on the controllable parameters and our results may lead to insights in the development of active dampeners and smart fluids. Since we see complex behaviour even in this simple system, it is expected that the macroscopic behaviour of such suspensions may be much more complex in more complex flows.     

Osteoblast cell response to β-tricalcium phosphate scaffolds with controlled architecture in flow perfusion culture system

Porous β-tricalcium phosphate (β-TCP) scaffolds with controlled architecture and improved mechanical properties were fabricated by combining the gel-casting and rapid prototyping techniques. The pore morphology, size, and distribution of the β-TCP scaffolds were characterized using a scanning electron microscope. The porosity of the resulting scaffolds with pore size range from 300 to 500 μm was 46%. The average compressive strength was 16.1 MPa. X-ray diffraction was used to determine the crystal structure and chemical composition of scaffolds. The result indicated that the sintering process has not changed the composition of β-TCP. Flow perfusion culture system was developed in our lab to improve mass transfer for seeded cells. For scaffold/cell constructs cultured under flow perfusion for 4, 8, and 16 days, there was greater scaffold cellularity and alkaline phosphatase activity compared with static culture condition. These results indicated that flow perfusion culture system had evident effects on osteoblast viability and functions in vitro.     

New Design of Quaternary Sequences

 We construct new families of quaternary periodic sequences having good autocorrelation properties that are useful for the synchronisation of messages in multiple access communications systems. The design of these quaternary periodic sequences makes use of a general construction based on the Gray map starting from couples of binary words with particular weight or correlation properties. Received: June 26, 2000; revised version: January 21, 2002     

Application of a variational approach to the investigation of three-dimensional stress-strain states of layered plates on a rigid base

By using a variational approach, we deduce a system of resolving equations that describes the three-dimensional stress-strain state of a layered plate. For the special case of hinged support along the contour, this system is analytically solvable in the three-dimensional case. To verify the proposed approach, we compared our results with known solutions. The case of a plate supported by a rigid base is also investigated. Translated from Problemy Prochnosti, No. 6, pp. 86–94, November–December, 1997.     

Pressure induced structural behaviour in f-electron based AB, AB2 and AB3 intermetallics

The rare-earth and actinide based compounds are endowed with several exotic physical and chemical properties due to the presence of f-electrons. Under pressure, the nature of f-electrons can be changed from localized to itinerant, leading to significant changes in their structural, physical and chemical properties. The present review on these f-electron based binary intermetallics compounds is an outcome of a detailed literature survey as well as our own research` during the last one decade. It attempts to bring out the structural sequences observed among the various homologues and their correlations with their electronic structure. It is seen that the majority of the AB type compounds show the NaCl to CsCl type structural transformation; whereas the AB₃ type compounds stabilizing in cubic structure at STP, remain stable over a wide pressure range. However, the AB₂ type compounds exhibit a variety of structural transitions, which broadly fall into the following sequence: MgCu₂ →.......... → CeCu₂ → AlB₂ → ZrSi₂ → ThSi₂ → SmSb₂ →.......... Further, the structural transitions, the transition pressures and bulk modulii values in any homologous series are seen to follow a systematic trend with respect to the atomic numbers of their constituent elements.     

3D velocity from 3D Doppler radial velocity

We present local least squares and regularization frameworks for computing 3D velocity (3D optical flow) from 3D radial velocity measured by a Doppler radar. We demonstrate the performance of our algorithms quantitatively on synthetic radial velocity data and qualitatively on real radial velocity data, obtained from the Doppler radar at Kurnell Radar station, Botany Bay, New South Wales, Australia. Radial velocity can be used to predict the future positions of storms in sequences of Doppler radar datasets.© 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 189–198, 2005     

The activation of 〈c + a〉 non-basal slip in Magnesium alloys

The activation of 〈c + a〉 non-basal slip system can help to improving the mechanical properties of Magnesium alloys. The activation conditions of 〈c + a〉 non-basal slip system in Mg alloys are reviewed, such as the addition of lithium elements, increasing temperatures, and regions of stress concentration, and so on. Moreover, the article summarizes our results from the work on Mg alloys using equal channel angle pressing with back pressure, and points out that 〈c + a〉 non-basal slip systems also become active much easier under hydrostatic pressure, which will help to open new window to explore the basic physics of the activation of non-basal slip.     

Modelling the effects of the Austrian inpatient reimbursement system on length-of-stay distributions

Abstract. This paper analyses the effects of the new Austrian performance-oriented inpatient payment system on discharge strategies of hospitals by investigating length-of-stay (LOS) distributions. Using generalised linear models applied to data from 1998, we calculate the impact of day and month of admission as well as types of admission and discharge on the LOS of inpatients with major diagnoses. Hereby, we prove significant interdependencies among these variables and reveal hospital behaviour such as 1) premature discharges of inpatients or “unbundling” and 2) “patient splitting”. Hence, our findings illustrate that hospitals react to incentives set by the new system in order to maximise their revenues. Hence, the current reimbursement system still has potential for cost reduction while maintaining high quality of health care. Our strategic policy model supports decision makers in disclosing these effects and provides policy implications to close exploitable gaps within the new reimbursement system. RID="We are grateful to experts of the federal funds and the Ministry of Labour, Health and Social Affairs for providing us with detailed information on the Austrian reimbursement system for inpatients and for approving our data request. In addition, we especially thank Dr. Wilhelm Frank of the Austrian Federal Institute for Health Care for making the needed inpatient data available for us. Special thanks are due to Professor Arjan Shahani, Paul Harper and Sally Brailsford (University of Southampton, United Kingdom), Professor Lucas Delesie (Catholic University of Leuven, Belgium), Professor Bernhard Schwarz (University of Vienna, Austria) and Professor Engelbert Dockner (University of Vienna, Austria) for valuable comments on this investigation. Correspondence to:M. Rauner     

Extended pseudorandom sequences and two-dimensional coding collimators based on them

A new extensive class of one-dimensional binary sequences, called extended pseudorandom sequences, is proposed which enables a radiation-physics experiment to be optimized more completely and enables problems of planar emission tomography to be solved effectively using integral-code measuring systems. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 66–71, June, 2007.     

A Perspective on Multi-scale Simulation: Toward Understanding Water-silica

We discuss the conceptual and practical developments that evolved over the past seven-plus years when our multidisciplinary team took on the challenge of understanding a single complex system – water and silica – through multi-scale modeling and simulation. The discussion provides the context for the ten contributions, from various groupings of the team, that make this coordinated special issue. In the evolution of our project, we have come to appreciate the need for a framework that essentially defines the intellectual basis of computational science. We have found that the usual utilitarian notion of simulation is lacking a conceptual counterpart: by itself, it does not address the scientific challenge of analyzing complex phenomena, such as chemo-mechanical processes, across various length scales. The problem of water and silica is prototypical with regard to many complex systems of current interest. In them, the effects of chemical activity and dynamical stress are involved simultaneously and essentially. This essential dependence presents opportunities for a multi-scale strategy that combines quantum and classical methods of simulation. As often is the case with “obvious” approaches, one encounters many subtle aspects. We summarize the issues we have encountered, thus laying the ground work for the detailed topical papers that follow.     

Formation of acoustooptical bound states by optical pulses

An interesting aspect of the acoustooptical interaction is studied in this paper — the formation of acoustooptical bound states by optical pulses. An analysis is made of the solution of a system of three nonlinear partial differential equations describing the case of collinear acoustooptical interaction. A specific example of this solution is examined for the case of the interaction of a sequence of acoustic pulses with a digital sequence of optical pulses. It is shown that the values of the recorded sequences of scattered light correspond to the logical operation “ AND” operating on the sequence of acoustic and optical pulses, that is, a programmable switching of the input optical digital signal by a sequence of acoustic pulses occurs. The experiment reported in this paper corresponds to the case of detuning of the wave vectors, but on the whole it supports the calculations In summary, this work demonstrates (experimentally and theoretically) the possibility of realizing an optoelectronic programmable switching of optical signals. Pis’ma Zh. Tekh. Fiz. 23, 88–95 (January 26, 1997)     

基于动态可变参数的复合混沌系统的语音加密算法研究

利用混沌理论,基于Hénon映射和Logistic映射设计了一个复合混沌系统,并证明了其具有更好的初值敏感性。对产生的混沌二值序列进行美国国家标准与技术研究所(National Institute of Standard and Technology,NIST)随机数测试,分析得出该序列具有较好的随机性,可用于加密。依此设计了一个语音加密算法,实现了语音信号的加/解密功能。仿真分析表明,该混沌语音加密算法具有较高的安全性,能产生足够的密钥空间,有较强的保密性能。     

Mapping technological innovations through patent analysis: a case study of foreign multinationals and indigenous firms in China

This study attempts to expand the work on patenting activities of China. The characteristics of foreign multinationals and indigenous entities’ patenting activities in the US patent system are examined in our analysis. This study also attempts to model the diffusion trajectories of patenting activities that result from the functioning of two competing innovation system models adopted by China-FDI and indigenous—to compare the extent of divergence of technological innovations. The findings are useful for highlighting the path of technological innovations and understanding the dynamic potentials through analysis of the growth process. While the results suggest a dominance of foreign firms in patenting activities since the early 2000s, there is a sign of transition from industrial-based to knowledge-driven activities and the formation of evolving propagating behaviour in the production of indigenous technology.     

Obtaining Kohn-Sham potential without taking the functional derivative

Over the past decade and a half, many new accurate density functionals, based on the generalized gradient approximation, have been proposed, and they give energies close to chemical accuracy. However, accuracy of the energy functional does not guarantee that its functional derivative, which gives the corresponding potential, is also accurate all over space. For example, although the Becke88 exchange-energy functional gives very good exchange energies, its functional derivative goes as —1/2 m comparison to the correct —1 for r ⇇ where ris the distance of the electron from a finite system. On the other hand, accuracy of the potential is of prime importance if one is interested in properties other than the total energy; properties such as optical response depend crucially on the potential in the outer regions of a system. In this paper we present a different approach, based on the ideas of Harbola and Sahni, to obtain the potential directly from the energy density of a given approximation, without taking recourse to the functional derivative route. This leads to a potential that is as accurate as the functional itself. We demonstrate the accuracy of our approach by presenting some results obtained from the Becke88 functional.     

基于混沌正交组合序列的M元码分多址水声通信

提出了M元能量检测器算法,该算法简单易实现,极大优化了M元码分多址系统接收机结构和解码运算量。同时,M元能量检测器具有抗载波相位跳变和抗水声信道多途干扰的能力。针对M元码分多址水声通信系统中所需扩频序列数量庞大、选码难度高的问题,提出了混沌正交组合序列,通过简单的迭代组合即可产生大量满足要求的扩频序列,而且同族的混沌正交组合序列间满足正交关系。海试试验成功实现了7个用户的M元码分多址水声通信试验(M=512),共采用了3 584条混沌正交组合序列,每个用户通信速率为70 bit.s-1,验证了算法的有效性,为网络化水声通信的应用提供了技术基础。     

Structural investigations on lead-free Bi<Subscript>1/2</Subscript>Na<Subscript>1/2</Subscript>TiO<Subscript>3</Subscript>-based piezoceramics

In this study, recent results from our electron, X-ray, and neutron-diffraction experiments with emphasis on the binary Bi_1/2Na_1/2TiO₃-BaTiO₃ (BNT–BT) and ternary Bi_1/2Na_1/2TiO₃–BaTiO₃–K_0.5Na_0.5NbO₃ (BNT–BT–KNN) system are presented and contrasted with literature. The experimental results clearly revealed a phase coexistence on the nanoscale level. A systematic study of superlattice reflections in conjunction with microstructural characteristics showed that the BNT-based systems have specific properties in common, which, however, strongly depend on composition. In situ transmission electron microscopy (TEM) electric field experiments unequivocally demonstrated the evolution of lamellar domains. Combining in situ TEM results with published in situ neutron-diffraction experiments, we proposed an electric field-induced phase transition that results in the giant unipolar and bipolar strain observed in specific compositions of the ternary system.     

Nondestructive Microstructural Analysis of Porous Bioceramics by Microfocus X-ray Computed Tomography (μCT): A Proposed Protocol for Standardized Evaluation of Porosity and Interconnectivity Between Macro-pores

Microfocus X-ray computed tomography (μCT) has now become widely available for the nondestructive evaluation of porous bioceramics suitable for use as a bone substitute in orthopedic surgery. As part of an official Japanese working committee, we recently participated in the preparation of a proposed standard protocol for the quantitative μCT analysis of porous bioceramics sent to the International Organization for Standardization (ISO). In this protocol, the recommended basic conditions for analysis were [field of view (XY plane): 3.0 mm, spatial resolution: 6 μm/pixel (or the closest minimal values available for both parameters on a particular μCT system), matrix size: 512 pixels], and we have now further determined the optimal values for more detailed parameters (e.g., threshold determination). To validate the utility of the complete protocol, three different types of ceramic sample [a ceramic of β-tricalcium phosphate (β-TCP) and two types of hydroxyapatite (HAp) with different porosities] were evaluated with three different types of cone-beam μCT scanner (the Shimadzu SMX-100CT, Shimadzu inspeXio-90CT, and Skyscan-1174 scanners). Acquired images were quantified using 3D-reconstruction software, VGStudio MAX (version 1.2). After comparing data obtained from these three μCT scanners, we have found that determinations of both porosity and pore-interconnectivity were very similar from one system to the other although the total number of measured pores did vary between scanners. The present data indicate that our protocol for μCT analysis is reliable enough to quantify the porosity and interconnectivity of porous bioceramics and would therefore facilitate both large-scale screening and quality control of porous bioceramic samples.     

Combined scheduling algorithm for re-entrant batch-processing machines in semiconductor wafer manufacturing

In this paper, a new combined scheduling algorithm is proposed to address the problem of minimising total weighted tardiness on re-entrant batch-processing machines (RBPMs) with incompatible job families in the semiconductor wafer fabrication system (SWFS). The general combined scheduling algorithm forms batches according to parameters from the real-time scheduling simulation platform (ReS²), and then sequences batches through slack-based mixed integer linear programming model (S-MILP), which is defined as batch-oriented combined scheduling algorithm. The new combined scheduling algorithm obtains families’ parameters from ReS² and then sequences these families through modified S-MILP, which is defined as family-oriented combined scheduling algorithm. With rolling horizon control strategy, two combined scheduling algorithms can update RBPMs scheduling continually. The experiments are implemented on ReS² of SWFS and ILOG CPLEX, respectively. The results demonstrate the effectiveness of our proposed methods.