High Rate Data Synchronization in GALS SoCs

Globally asynchronous, locally synchronous (GALS) systems-on-chip (SoCs) may be prone to synchronization failures if the delay of their locally-generated clock tree is not considered. This paper presents an in-depth analysis of the problem and proposes a novel solution. The problem is analyzed considering the magnitude of clock tree delays, the cycle times of the GALS module, and the complexity of the asynchronous interface controllers using a timed signal transition graph (STG) approach. In some cases, the problem can be solved by extracting all the delays and verifying whether the system is susceptible to metastability. In other cases, when high data bandwidth is not required, matched-delay asynchronous ports may be employed. A novel architecture for synchronizing inter-modular communications in GALS, based on locally delayed latching (LDL), is described. LDL synchronization does not require pausable clocking, is insensitive to clock tree delays, and supports high data rates. It replaces complex global timing constraints with simpler localized ones. Three different LDL ports are presented. The risk of metastability in the synchronizer is analyzed in a technology-independent manner     

用于电压或电流调节的新调节器架构

一种新的调节器架构为分散热量和电流调节提供了解决方案。这些新的调节器具有优于从前器件的性能。     

Inclusion complete tally languages and the Hartmanis-Berman conjecture

Stimulated by the work of Hartmanis and Berman [5], we study the question of the existence of a tally languageL inNP such thatL is inP if and only ifP = NP. The method used is applicable to questions regarding the comparison of a wide range of pairs of classes of formal languages specified by machines whose computational resources are bounded in time or space.This research was supported in part by the National Science Foundation under Grants MCS76-05744 and MCS77-11360.     

Searching for empty convex polygons

A key problem in computational geometry is the identification of subsets of a point set having particular properties. We study this problem for the properties of convexity and emptiness. We show that finding empty triangles is related to the problem of determining pairs of vertices that see each other in a star-shaped polygon. A linear-time algorithm for this problem which is of independent interest yields an optimal algorithm for finding all empty triangles. This result is then extended to an algorithm for finding empty convex r-gons (r> 3) and for determining a largest empty convex subset. Finally, extensions to higher dimensions are mentioned.The first author is pleased to acknowledge support by the National Science Foundation under Grant CCR-8700917. The research of the second author was supported by Amoco Foundation Faculty Development Grant CS 1-6-44862 and by the National Science Foundation under Grant CCR-8714565.     

Effect of angiotensin-converting enzyme inhibition on bronchial responsiveness

BACKGROUND: Many studies have shown that CA 125 levels frequently rise prior to clinical evidence of progression of ovarian cancer. For clinical trials an accepted definition of progression according to CA 125 is required. We therefore determined what change in CA 125 level was the most accurate predictor of relapse in patients on follow up after therapy for ovarian cancer. PATIENTS AND METHODS: Serial CA 125 levels were studied from 255 patients entering the North Thames Ovary Trial of 5 versus 8 courses of chemotherapy. An initial analysis was made 2 months after closure of the trial, a more detailed analysis was made after 81 confirmed relapses among evaluable patients and a final analysis was made one year later with longer follow-up. RESULTS: On the basis of the results from the interim analyses and the cut-off level of 22-35 U/ml used by different laboratories, 30 U/ml was chosen as the upper limit of normal. In the final analysis a doubling of CA 125 from the upper limit of normal was defined as progression. Using this method sensitivity was 85.9%, specificity 91.3%, positive predictive value 94.8%, and negative predictive value was 77.8%. Insisting on a confirmatory elevated CA 125 level reduced the false positive rate to < 2% with a sensitivity of 83.9%. The median lead-time prior to clinical progression was 63 days. CONCLUSION: A confirmed rise of serum CA 125 level to more than twice the upper limit of normal during follow up after first line chemotherapy accurately predicts tumour relapse.     

Visibility with a moving point of view

We investigate three-dimensional visibility problems in which the viewing position moves along a straight flightpath. Specifically we focus on two problems: determining the points along the flightpath at which the topology of the viewed scene changes, and answering ray-shooting queries for rays with origin on the flightpath. Three progressively more specialized problems are considered: general scenes, terrains, and terrains with vertical flightpaths.Supported in part by NSF Grant CCR87-00917 and a Guggenheim Fellowship. Work done while visiting Xerox PARC.Work done while at Xerox PARC.Work done while visiting Xerox PARC.     

Primitives for the manipulation of three-dimensional subdivisions

Algorithms for manipulating three-dimensional cell complexes are seldom implemented due to the lack of a suitable data structure for representing them. Such a data structure is proposed here along with the primitive operations necessary to make it useful. Applications of the structure are also given.This work was supported in part by the National Science Foundation under Grant No. DCR85-05517.     

Predicting boys' early-onset substance abuse from father's alcoholism, son's disruptiveness, and mother's parenting behavior.

Sons of male alcoholics (SOMAs) are said to be at risk for alcoholism. The present study examined 4 groups of 13-year-old boys: SOMAs with and without disruptive behaviors, disruptive boys who were not SOMAs, and control participants. The classification of disruptive was based on 7-year longitudinal data, and father's alcoholism was determined by standardized tests. Mothers' nurturance and promotion of autonomy were assessed in a laboratory setting; boys' substance abuse was measured by self-report methods in the same year as the observation. Boys with disruptive behaviors showed the most substance abuse; no effect of father's alcoholism was found. Disruptive boys' mothers were significantly less nurturant and demanded obedience rather than promoted autonomy. A multiple regression analysis revealed that the boys' disruptive behavior and the mother's lack of nurturance predicted early-onset substance abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Primitives for the manipulation of three-dimensional subdivisions

Algorithms for manipulating three-dimensional cell complexes are seldom implemented due to the lack of a suitable data structure for representing them. Such a data structure is proposed here along with the primitive operations necessary to make it useful. Applications of the structure are also given.