The approximation of image blur restoration filters by finite impulse responses

Image blur can often be modeled by a linear spatially invariant, symmetric point spread function. For this class of functions, several restoration filters are known in the literature. The approximation of their frequency transfer functions (ftf's) by the ftf's of small finite impulse response (FIR) filters has been studied. Accurate approximations will be possible by 9 × 9 FIR's with 8-bit elements if the approximation is done in a weighted MMSE sense, and if the truncation of the element values will be carried out such that the errors are small. A heuristic truncation algorithm MINIM will be described. An example of restoration by a 9 × 9 FIR will be shown.     

Coreceptor usage of human immunodeficiency virus type 2 primary isolates and biological clones is broad and does not correlate with their syncytium-inducing capacities

Entry of human immunodeficiency virus type 1 (HIV-1) into target cells is mediated by binding of the surface envelope glycoprotein to the CD4 molecule. Interaction of the resulting CD4-glycoprotein complex with alpha- or beta-chemokine receptors, depending on the biological phenotype of the virus, then initiates the fusion process. Here, we show that primary HIV-2 isolates and biological clones, in contrast to those of HIV-1, may use a broad range of coreceptors, including CCR-1, CCR-3, CCR-5, and CXCR-4. The syncytium-inducing capacity of these viruses did not correlate with the ability to infect via CXCR-4 or any other coreceptor. One cell-free passage of the intermediate isolates in mitogen-stimulated, CD8+ cell-depleted peripheral blood mononuclear cells resulted in the outgrowth of variants with CCR-5 only, whereas the coreceptor usage of late and early isolates did not change. Since HIV-2 is less pathogenic in vivo than HIV-1, these data suggest that HIV pathogenicity in vivo is not directly related to the spectrum of coreceptors used in in vitro systems.     

Pharmacokinetics and anti-HIV-1 efficacy of negatively charged human serum albumins in mice

Changes of blood metabolites and hormones were studied in female breeding calves before, during and after weaning from 4 to 18 weeks of age. Calves were initially fed increasing amounts of whole milk (up to 7 kg/day in week 8 of life). Milk intake was then gradually decreased up to the age of 16 weeks, when calves were completely weaned and only fed hay and concentrates. Average daily gain was 0.85 kg. Postprandial concentrations of glucose, insulin, insulin-like growth factor-I and 3.5.3'-triiodothyronine concentrations gradually decreased (P < 0.05) with age, while those of beta-hydroxybutyrate, protein, albumin, haemoglobin and iron increased (P < 0.05). Concentrations of cholesterol transiently increased, whereas those of urea reversibly decreased. Non-esterified fatty acids, triglycerides and growth hormone did not consistently change during the duration of the study. In conclusion, changes of glucose, beta-hydroxybutyrate, haemoglobin, iron, insulin, insulin-like growth factor-I and 3.5.3'-triiodothyronine were markedly different from those usually seen in veal calves of the same age.     

Age-dependent effects of muscle vibration and the Jendrassik maneuver on the patellar tendon reflex response

OBJECTIVE: To explore possible effects of aging on the excitability of spinal reflexes. DESIGN: Using a cross-sectional design, the influences of muscle vibration and the Jendrassik maneuver on patellar tendon reflex function were compared between 30 young adults and 15 older adults. SETTING: Motor control research laboratory. SUBJECTS: The young adults were volunteers of college age. The older adults (74.5 +/- 4.14 yr) were volunteers from the local community. All subjects were free of medications and neurological conditions that would affect normal neuromuscular responses. MAIN OUTCOME MEASURES: A force-time curve analysis of the patellar tendon reflex response was used to assess the inhibition and facilitation of spinal reflexes. In the experimental protocol to assess spinal reflex inhibition, 100 Hz vibration was applied to the right quadriceps muscle. In another experimental protocol, spinal reflex facilitation was assessed using the Jendrassik maneuver. To perform the Jendrassik maneuver, subjects were instructed to grasp their hands together and to pull as hard as possible while breathing normally. After a 2-second count, the tendon tap was delivered to the right leg and the subject was instructed to relax. In both experimental protocols, control patellar tendon reflexes were collected. RESULTS: Analysis of variance for reflex peak force revealed a significant 30% reduction in the amount of vibration-induced reflex inhibition with increasing age, and a similar 33% reduction in the amount of Jendrassik maneuver facilitation observed for the older adults as compared with the younger adults. CONCLUSION: These results support the hypothesis that inhibitory and excitatory influences acting on the alpha motoneuron pool are different in young and older adults.     

基于ESL并采用SystemC和SystemVerilog的设计流程

ESL解决方案的目标在于提供让设计人员能够在一种抽象层次上对芯片进行描述和分析的工具和方法,在这种抽象层次上,设计人员可以对芯片特性进行功能性的描述,而没有必要求助于硬件(RTL)实现的具体细节。     

Improved small-signal analysis for the phase-shifted PWM power converter

A closed form cycle by cycle analysis forms the basis for a new zero-voltage switching (ZVS) phase-shifted PWM (PSPWM) full bridge power converter small-signal model. The paper derives the small-signal response equations. The PSPWM converter has an implicit "slew interval," making the converter dynamics difficult to analyze using traditional averaging techniques. The converter control to output transfer function under continuous conduction mode operation and using voltage-mode control does not exhibit a second order pole associated with the output L-C filter, making it different from a conventional PWM converter. This new PSPWM converter model shows that the output L-C filter is separated into two real poles, with one pole held at constant frequency independent of operating conditions. A characteristic pole depends only upon the converter switching frequency and inductor values. This characteristic pole is fundamental to understanding the PSPWM converter natural and forced responses. The new small-signal model is shown to be in excellent agreement with experimental results.     

Bücherschau

Ohne Zusammenfassung VDI     

可验证性设计方法大幅提升设计品质和验证效率

要解决当前验证中存在的核心问题,必须采用可验证性设计方法,它是一种全面的、架构化的设计和验证方法,目的在于推动用于下一代IC设计的验证解决方案。     

Linear-programming-based heuristics for project capacity planning

Many multi-project organizations are capacity driven, which means that their operations are constrained by various scarce resources. An important planning aspect in a capacity driven multi-project organization is capacity planning. By capacity planning, we mean the problem of matching demand for resources and availability of resources for the medium term. Capacity planning is a very useful method to support important tactical decisions such as due date quotation and price quotation for new projects, and to gain an insight into capacity requirements for the medium term. We present a capacity planning model in which aspects such as capacity flexibility, precedence relations between work packages, and maximum work content per period can be taken into account. For this model, we discuss several linear-programming-based heuristics. Using a large set of test instances, we compare these heuristics with some results from the literature. It turns out that some of these heuristics are very powerful for solving capacity planning problems.