60,835 research outputs found

    UKC ANSAware Survival Guide (for Modula-3)

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    The ANSAware platform is a suite of libraries and tools which facilitate the building of distributed applications. The documentation with the release forms little more that a reference manual to the language and does not aid the first time user. This document provides a simple introduction to distributed systems concepts and, through the use of an example, demonstrates how to build applications with ANSAware

    Fast Recompilation of Object Oriented Modules

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    Once a program file is modified, the recompilation time should be minimized, without sacrificing execution speed or high level object oriented features. The recompilation time is often a problem for the large graphical interactive distributed applications tackled by modern OO languages. A compilation server and fast code generator were developed and integrated with the SRC Modula-3 compiler and Linux ELF dynamic linker. The resulting compilation and recompilation speedups are impressive. The impact of different language features, processor speed, and application size are discussed

    Određivanje fizičkih i mehaničkih svojstava ploča izrađenih od otpadnog papira i ojačanih drvnim iverjem te usitnjenim staklenim vlaknima

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    Today, legal regulations, along with social awareness, have made waste management a necessity. Depending on the type of waste, technological developments have enabled an increase in the number of approaches, e.g., reusing, recycling, and manufacturing of different products. In this study, low-density boards were produced using different proportions of office waste paper, wood chips, and chopped E-glass fiber. Waste paper and glass fiber formed the middle layer of the boards and wood chips comprised the surface layers. The density, water absorption, and thickness swelling properties of the boards were investigated. Among the mechanical properties, the modulus of rupture, modulus of elasticity, and internal bond strength were determined. The use of wastepaper led to a reduction in the modulus of rupture and modulus of elasticity of the boards. An increase in the glass fiber ratio contributed positively to the water absorption and thickness swelling properties, whereas it directly led to decreases in the internal bond strength, and the modulus of rupture and modulus of elasticity values. Nonetheless, the low-density boards were able to meet the minimum modulus of rupture and modulus of elasticity specified in ANSI 208.1 standards, while only one variation met the IB requirements.U današnje je vrijeme zakonska regulativa, uz društvenu svijest, gospodarenje otpadom učinila nužnošću. Ovisno o vrsti otpada, tehnološki je razvoj omogućio povećanje broja pristupa gospodarenju otpadom, npr. pri ponovnoj uporabi, recikliranju i proizvodnji različitih proizvoda. Za ovo su istraživanje izrađene ploče niske gustoće s različitim udjelima otpadnoga uredskog papira, drvnog iverja i usitnjenih staklenih vlakana. Pritom su otpadni papir i usitnjena staklena vlakna iskorišteni za izradu središnjeg sloja, a drvno je iverje upotrijebljeno za vanjske slojeve ploča. Izrađene su ploče ispitane i utvrđena je njihova gustoća, moć upijanja vode i debljinsko bubrenje. Dodatno su određeni modul loma, modul elastičnosti i čvrstoća raslojavanja. Rezultati ispitivanja pokazali su da je uporaba otpadnog papira pridonijela smanjenju vrijednosti modula loma i modula elastičnosti. Istodobno je povećanje udjela usitnjenih staklenih vlakana imalo pozitivan učinak na vrijednosti upijanja vode i na debljinsko bubrenje, ali je izravno utjecalo i na smanjenje čvrstoće raslojavanja, modula loma i modula elastičnosti. Ipak, izrađene ploče niske gustoće zadovoljile su minimalne zahtjeve norme ANSI 208.1 glede modula loma i modula elastičnosti, a samo je jedna skupina eksperimentalno izrađenih ploča zadovoljila uvjete čvrstoće raslojavanja

    A Novel Three-Point Modulation Technique for Fractional-N Frequency Synthesizer Applications

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    This paper presents a novel three-point modulation technique for fractional-N frequency synthesizer applications. Convention modulated fractional-N frequency synthesizers suffer from quantization noise, which degrades not only the phase noise performance but also the modulation quality. To solve this problem, this work proposes a three-point modulation technique, which not only cancels the quantization noise, but also markedly boosts the channel switching speed. Measurements reveal that the implemented 2.4 GHz fractional-N frequency synthesizer using three-point modulation can achieve a 2.5 Mbps GFSK data rate with an FSK error rate of only 1.4 %. The phase noise is approximately -98 dBc/Hz at a frequency offset of 100 kHz. The channel switching time is only 1.1 μs with a frequency step of 80 MHz. Comparing with conventional two-point modulation, the proposed three-point modulation greatly improves the FSK error rate, phase noise and channel switching time by about 10 %, 30 dB and 126 μs, respectively

    Improving the performance of bright quantum dot single photon sources using amplitude modulation

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    Single epitaxially-grown semiconductor quantum dots have great potential as single photon sources for photonic quantum technologies, though in practice devices often exhibit non-ideal behavior. Here, we demonstrate that amplitude modulation can improve the performance of quantum-dot-based sources. Starting with a bright source consisting of a single quantum dot in a fiber-coupled microdisk cavity, we use synchronized amplitude modulation to temporally filter the emitted light. We observe that the single photon purity, temporal overlap between successive emission events, and indistinguishability can be greatly improved with this technique. As this method can be applied to any triggered single photon source, independent of geometry and after device fabrication, it is a flexible approach to improve the performance of solid-state systems, which often suffer from excess dephasing and multi-photon background emission

    Hybrid M-FSK/DQPSK Modulations for CubeSat Picosatellites

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    Conventional CubeSat radio systems typically use one of several basic modulations, such as AFSK, GMSK, BPSK, QPSK and OOK or switch between them on demand if possible. These modulations represent a bal¬anced trade-off between good energy efficiency of high order M-FSK modulation and good spectral efficiency of high order M-QAM modulation. Utilization of modulations with the best energy efficiency is not possible due to strict limits on occupied frequency bandwidth. In this paper the proposed group of hybrid modulations and proposed hybrid modulator and demodulator are presented. Novel solution offer interesting possibilities of increasing spectral efficiency as well as energy efficiency of basic M-FSK modulation by embedding DQPSK symbols between two M-FSK symbols. Such group of hybrid modulations offers suitable properties for picosatellite, e.g. simple realization onboard the picosatellite, better energy and spectral efficiency, low PAPR, wide range of adaptation by changing the order of M-FSK, suitable for easy non-coherent demodulation, good immunity to Doppler effect with DM-FSK coding

    Pulse-width modulation multiplier Patent

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    Pulse duration modulation multiplier syste

    Method and apparatus for quadriphase-shift-key and linear phase modulation

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    A submultiple of an S-band transmitter output frequency was divided equally between a linear phase modulation branch and a QPSK modulation branch. The linear modulation branch includes a multiplier to increase the carrier frequency to a level which, when combined with the carrier in the QPSK branch in an up-converter (utilizing a mixer at the input followed by a bandpass filter), produces the transmitter output frequency. This allows the QPSK modulator to operate at one-eighth of the output frequency where repeatable and precisely controlled modulation can be easily achieved. This also allows linear phase modulation at one-eighth the output frequency where low modulator deviation and good linearity can be easily maintained
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