98 research outputs found
Simulation and implementation of a linear predictive coder
The main objective of this research was to design and build
a Linear Predictive Coder (LPC) based on the TMS320 processor,
and to incorporate this in the design of a low bit rate voice
coding server for a Cambridge Ring. In order to decide on a
suitable algorithm for the LPC, extensive simulations were
carried out on a BBC computer. The computer used was interfaced
to a frame store which, although its original purpose was
to store video information, acted as a suitable store for
speech. Up to six seconds of speech could be fed in from a
microphone in real time for analysis. The BBC was fitted with
a second processor, but in spite of this the processing times
were very slow. [Continues.
Grup Excursionista Muntanya i Mar
A partir de novembre de 1949 el títol es canvia al castellà "Grupo Excursionista Montaña y Mar"VILADOT-CEDO
GENETIC VARIATION AND POPULATION STRUCTURE IN THE HUMPBACK GROUPER, Cromileptes altivelis, TROUGHOUT ITS RANGE IN INDONESIAN WATERS
Starch gel electrophoresis was used to assess the level and distribution ofgenetic variation in humpback grouper, Cromileptes altiuelis sampled from 4 different areas of coral reefs in Raas and Kangean located in Madura as well as Sangeang and Bungin located in Sumbawa regions, between December 1997 and March 1998
GENETIC VARIATION IN CULTURED STOCKS OF TIGER SHRIMP (Penoeus monodon) IN INDONESIA
Three stocks of tiger shrimps, Penaeus monndon, obtained from brackish water pond culture in Aceh (Sumatera Island), Cilacap (Java Island) and Sumbawa (West Nusatenggara) were assayed for allozyme variation at 9 enzyme loci from muscle biopsies
Rising Public College Tuition and College Entry: How Well Do Public Subsidies Promote Access to College?
Though economists have spent the past decade analyzing the rising payoff to schooling, we know much less about the responses of youth or the effectiveness of policies aimed at influencing those decisions. States and the federal government currently spend more than $53 billion annually, hoping to promote greater access to college. This paper evaluates the price sensitivity of youth, using several sources of non-experimental variation in costs. The bulk of the evidence points to large enrollment impacts, particularly for low-income students and for those attending two-year colleges. The states have chosen to promote college enrollment by keeping tuition low through across-the-board subsidies rather than using more targeted, means-tested aid. As public enrollments increase, this has become an expensive strategy. Means-tested aid may be better targeted. However, the evidence of enrollment responses to such targeted aid is much weaker. After a federal means-tested grant program was established in 1973, there was no disproportionate increase in enrollment by low-income youth. Given the number of public dollars at stake, the two sets of results should be reconciled.
On the design of IEEE compliant floating point units and their quantitative analysis
Abstract this thesis addresses the question of which are the important issues in the design of a high-speed floating-point unit (FPU) that is fully compliant with the IEEE floating-point standard 754-1985 [19]. There are a few choices that need to be made when designing an IEEE compliant FPU, among them: the internal representation of floating-point numbers, the rounding algorithms, handling of denormal results, usage of the same rounding hardware for different units (e.g. adder, multiplier, divider), and the implementations of the adder, the multiplier and the divider. These choices influence both the cost and the performance of the FPU. Nevertheless, these issues have not been discussed in the open literature todate. This work begins to fill this gap by designing, analyzing and comparing 18 different IEEE compliant FPU implementations, that consider design options regarding: (a) the internal representation of floating-point numbers; (b) the rounding algorithms; (c) sharing of a rounding unit, the implementation of gradual step rounding or the implementation of dedicated rounding units for each functional unit; (d) the implementation of the floating-point multiplier; and (e) the implementation of the floating-point divider. The presented FPU designs make also use of the following innovations, that were developed in the context of this work: (a) a fast implementation of variable position rounding integrated into a FP multiplier [37]; (b) to the best of our knowledge the fastest integrated FP addition and rounding algorithm published todate [40], (c) the fastest FP multiplication rounding algorithm published todate [11, 12] and (d) the fastest linear reciprocal approximation implementation published todate. [36, 39]; (e) an efficient integration of single and double precision rounding [9]; (f) a Booth encoded adder-tree with an improved cost formula [30]. All the FPUs designed in this work are fully compliant with the IEEE standard for all implemented operations, support both single and double precision, and deal with denormal values and special cases in hardware. Because to design an IEEE compliant FPU is a complex and error-prone task, all the FPU designs are specified in full detail at gate level and the correctness of the FPU designs (in particular the compliance with the IEEE standard) is proven. The proposed FPU implementations are analyed and compared regarding the hardware cost, the cycle time and the performance that they achieve on traces of the SPECfp92 benchmark suite [17] integrated into a pipelined RISC processor from [23]. In this quantitative analysis [38] it is demonstrated that the choice of the rounding architecture in the FPU has a larger impact on the performance of the microprocessor than the choice of the FP multiplication or the FP division implementation. In comparison to this the impact of the rounding architecture choice on the cost is relatively small. The rounding architecture that uses dedicated rounding units provides the best performance with only small additional cost, so that this rounding architecture seems to be the best choice in floating-point implementations. The fast implementation of this rounding architecture is only made possible by the fast variable position rounding implementation for multipliers from [37]. This underlines the importance of this technique.In dieser Arbeit wird der Frage nachgegangen, welches die wichtigsten Designentscheidungen bei der Implementierung einer schnellen Gleitkommaeinheit (FPU), die dem IEEE Standard 754-1985 [19] genügt, sind. Es gibt verschiedene Entscheidungen, die beim Entwurf einer IEEE konformen FPU getroffen werden müssen, darunter: die internen Darstellungen der Gleitkomma-(FP) Zahlen, die Rundungsalgorithmen, die Art der Behandlung von denormalisierten Ergebnissen, die Mehrfachverwendung von Teilen der Hardware, wie z.B. die Benutzung derselben Rundungshardware für verschiedene Einheiten, und die Implementierungen des FP Addierers, des FP Multiplizierers und des FP Dividierers. Diese Entscheidungen beeinflussen sowohl die Kosten alsauch die Leistung der FPU. Nichtsdestotrotz wurden diese Entscheidungen bislang nicht in der Literatur diskutiert. Die vorliegende Arbeit setzt in dieser Lücke an. Es werden 18 unterschiedliche FPUs vorgestellt, analysiert und verglichen, die Optionen zu den folgenden Entscheidungen betrachten: (a) interne Darstellung der FP Zahlen; (b) Rundungsalgorithmen; (c) Gemeinsame Nutzung einer allgemeinen Rundungseinheit, Aufteilen des Rundens in mehrere Schritte und gemeinsame Realisierung einer Teilmenge dieser Schritte oder vollständige eigene Implementierung des Rundens für jede Funktionseinheit; (d) Implementierung des FP Multiplizierers; (e) Implementierung des FP Dividierers. Die vorgestellten FPU Designs benutzen darüberhinaus folgende Neuerungen, die im Rahmen dieser Arbeit entstanden sind: (a) eine schnelle Rundungsimplementierung für den FP Multiplizierer mit variabler Rundungsposition [37]; (b) nach unserem besten Wissen den bisher schnellsten publizierten Algorithmus zum Addieren und Runden von FP Zahlen [40], (c) den bisher schnellsten publizierten Algorithmus zum Runden bei der FP Multiplikation [11, 12] und (d) die bisher schnellste publizierte Implementierung einer linearen Approximation von Reziproken [36, 39]; (e) eine effiziente Integration des Rundens in single precision und double precision [9]; (f) einen Booth-Multiplizierer mit verringerten Kosten [30]. Alle entworfenen FPUs sind für alle implementierten Operationen vollständig konform zum IEEE FP Standard 754, unterstützen sowohl single alsauch double precision Zahlen, und behandeln selbst denormalisierte Ergebnisse und Spezialfälle in Hardware. Weil der Entwurf von IEEE konformen FPUs eine komplexe und fehleranfällige Aufgabe ist, werden sämtliche entworfenen FPUs detailiert auf Gatterebene spezifiziert und ihre Korrektheit (insbesondere die Konformität zum IEEE FP Standard 754) bewiesen. Die vorgestellten FPU Implementierungen werden bezüglich der Hardwarekosten, der Zykluszeit und der Leistung, die sie integriert in einen gepipelinten RISC Processor aus [23] auf Traces der SPECfp92 Benchmark Suite erbringen, analysiert und verglichen. In dieser quantitativen Analyse (siehe auch [38]) wird demonstriert, daß die Auswahl der Rundungs-Architektur einer FPU einen größeren Einfluß auf die Prozessorleistung hat als die Auswahl der Implementierung der FP Multiplikation oder der FP Division. Im Gegensatz dazu ist der Einfluß der Auswahl einer Rundungs-Architektur der FPU auf die Hardwarekosten vergleichsweise gering. Die Rundungs-Architektur, die vollständige eigene Rundungsimplementierungen für jede Funktionseinheit benutzt, liefert bei weitem die beste Leistung und ist lediglich geringfügig teurer als Varianten mit anderen Rundungs-Architekturen. Demzufolge scheint diese Rundungs-Architektur die beste Wahl in FP Implementierungen zu sein. Die schnelle Implementierung dieser Rundungs-Architektur wurde erst durch die schnelle Rundungsimplementierung für FP Multiplizierer mit variabler Rundungsposition nach [37] ermöglicht. Das unterstreicht die Bedeutung dieser Technik
Principled pattern curation to guide data-driven learning design
Special Issue in Honor of Dr. Randi Reppen; Guest Edited by Tove Larsson, Shelley Staples, Jesse EgbertInsights from corpus linguistics (CL) have informed language learning and materials design, among many other areas. An important nexus between CL and language learning is the use of Data-Driven Learning (DDL), which draws on the use of corpus data in the classroom and which brings opportunities for inductive language discovery. Within the ethos of DDL, learners are encouraged to discover patterns of language and, in so doing, foster more complex cognitive processes such as making inferences. While many studies on DDL concur on the success of this approach, it is still perceived as a marginal practice. Its success so far has been largely limited to intermediate to advanced level learners in higher education settings (Boulton and Cobb 2017). This paper aims to offer guiding principles for how DDL might have wider application across all levels (not just at Intermediate and above) and to set out exemplars for their application at different levels of proficiency. Based on insights from second language acquisition (SLA) and learner corpus research (LCR), the focus of this paper will be on identifying principles for the curation of language patterns that are differentiated for stage of learning. In particular, we are keen to build on recent and important work which looks at SLA through the lens of the usage-based (UB) models (that is, models that view language as being acquired through the use of and exposure to language).Ye
The influence of open and closed mouth phases on the marine fish fauna of the Swartvlei estuary
The Swartvlei estuary fish community was sampled during open and closed phases using seine and gill nets. Results showed a marked decline in the abundance of juvenile fish <50 mm TL but not of larger size groups following mouth closure. Both the catch per unit effort and size composition of gill-net catches revealed no major changes between the open and closed phase, indicating that no substantial emigration of large juveniles and adults occurred prior to mouth closure. Atherina breviceps, which breeds both in the estuarine and marine environment, showed minimal fluctuations in abundance and size distribution when comparing the open and closed phase. Salinities in the Swartvlei estuary remain above 10 °0/00 during the closed phase thus reducing the possibility of fish kills which have been recorded in the Bot River estuarine system
Annual report of the superintending school committee, selectmen and treasurer of the town of Sullivan, for the year ending March 1, 1880.
This is an annual report containing vital statistics for a town/city in the state of New Hampshire
Reports of the treasurer, selectmen, and superintending school committee of the town of Sunapee, for the year ending March 1st, 1876.
This is an annual report containing vital statistics for a town/city in the state of New Hampshire
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