AT&T (Netherlands)

We present a description of a new instrument development, HARPS3, planned to be installed on an upgraded and roboticized Isaac Newton Telescope by end-2018. HARPS3 will be a high resolution (R≃115,000) echelle spectrograph with a wavelength range from 380-690 nm. It is being built as part of the Terra Hunting Experiment - a future 10- year radial velocity measurement programme to discover Earth-like exoplanets. The instrument design is based on the successful HARPS spectrograph on the 3.6m ESO telescope and HARPS-N on the TNG telescope. The main changes to the design in HARPS3 will be: a customised fibre adapter at the Cassegrain focus providing a stabilised beam feed and on-sky fibre diameter ≈1:4 arcsec, the implementation of a new continuous ow cryostat to keep the CCD temperature very stable, detailed characterisation of the HARPS3 CCD to map the effective pixel positions and thus provide an improved accuracy wavelength solution, an optimised integrated polarimeter and the instrument integrated into a robotic operation. The robotic operation will optimise our programme which requires our target stars to be measured on a nightly basis. We present an overview of the entire project, including a description of our anticipated robotic operation.

Orthogonal Frequency Division Multiplexing (OFDM) has been proposed for future high speed wireless LANs and digital (television and audio) broadcasting as a promising multicarrier modulation technique. OFDM offers robustness against significant channel degradation by dispersion. For wireless LANs, the design of the transmitter power amplifier and the characteristics of the modulated signal are key factors deciding the coverage range performance and the product cost. The peak-envelope-power of the transmitter power amplifier is an important parameter in the design of small sized, low power wireless LAN devices. This paper describes an OFDM system with a data encoder/decoder that improves the peak-to-average power ratio of the transmitted signal. In this scheme, the data to be transmitted is converted into symbols for the individual subcarriers, such that the resultant of a pair of symmetrically positioned subcarriers is orthogonal to the resultant of another pair of subcarriers with the same center of symmetry. This conversion gives a reduced ratio between peak envelope-power and the mean (RMS) power, which reduces constraints on the power stage design. Further, the impact on the bit-error rate of clipping the signal in the transmitter before the output amplifier is discussed.

This paper discusses the decomposition of hostile intentions into abnormal behaviors. A list of such behaviors has been compiled for the specific case of public transport. Some of the deviant behaviors are hard to observe by people, as they are in the midst of the crowd. Examples are deviant walking patterns, prohibited actions such as taking photos and waiting without taking the train. We discuss our visual analytics algorithms and demonstrate them on CCTV footage from the Amsterdam train station.

Abstract The control system of a BISDN network will undoubtedly be very complex to design, implement and maintain. Its complexity has led researchers to look for ways of breaking down the problem into smaller and manageable parts. This has motivated the use of an object‐oriented approach to analyse and comprehend the BISDN control system. This paper thus presents an object‐oriented analysis (OOA) of a BISDN control system. This analysis is based on a method introduced by Coad and Yourdon and comprises five steps. All five steps, namely identifying subjects, identifying objects, identifying structures, defining attributes, and defining operations, will be worked out in detail with an emphasis on the user network interface (UNI) signalling protocol object. Four subjects, nine objects, and three structures are identified in the problem space at hand. This structuring offers a framework to analyse in detail the three aspects, data, structure and dynamic behaviour, of the UNI signalling protocol. A parallel between this approach and the well known approach used by the International Telecommunication Union (ITU) for specifying signalling protocols and contained in Recommendation I.130 is drawn. The Coad and Yourdon OOA approach applied to a BISDN control system can be used for the analysis of different aspects of such systems. This paper focuses on the UNI signalling protocol object which leads to a complete specification. Any protocol resulting from such analysis can be claimed to be object‐oriented protocol. This approach offers modularity and thus offers a way of structuring the problem space into identifiable objects and data. Full benefits of object orientation can be gained only in the consistent use of object orientation throughout all steps in the development process. The proposed approach allows one to create libraries of generic procedures which can be reused in specific implementations.

We study the delay in asymmetric cyclic polling systems with general mixtures of gated and exhaustive service, with generally distributed service times and switch-over times, in heavy traffic. We obtain closed-form expressions for all moments of the delay incurred at each of the queues. The expressions are strikingly simple and can even be expressed as finite products of known factors. The results provide new insights into the heavy-traffic behavior of polling systems.

The performance of radio modems with equalization and antenna diversity in indoor environments is analyzed. Results are presented for linear and nonlinear equalizers, and the outage characteristics are given as a function of the number of taps and the mean squared error at the output of the baseband processing section. The gain due to antenna diversity is also included. Finally, bounds on the penalty due to the residual ISI caused by the finite length of feedback section are presented.

Le legislateur francais vient de doter l'Autorite de la concurrence d'un nouveau pouvoir : celui de prononcer des injonctions structurelles lorsque les conditions tarifaires fixees par les entreprises…

Ficus microcarpa L. and Ficus virens Ait. V ar. sublanceolata (Miq.) Corner are two tree species of Moraceae. Due to the ir graceful crown and capability of growing on barren fields, these two species are extensively grown in Three Gorges Reservoir area. Because of the tree manage ment and the need of cuttings for propagation (the propagation of F. microcarp a and F. virens is mainly dependent on cuttage), branch cutting occurs qui te often to these two tree species in Three Gorges Reservoir area. Branch cuttin g may lead to an overall reduction of photosynthetic production in a tree becaus e of the large loss of productive leaf tissues. Therefore, in a branch-cut tree , the net productivity of remaining leaves, i.e. the leaf efficiency of remainin g leaves, is essential to tree's regrowth and recovery. However, since branch-c utting results in a higher ratio of unproductive wood to productive leaves due t o the unaffected stem and roots, and consequently per unit area of remaining lea ves in branch-cut trees has to bear more maintenance respiration costs, whether branch-cut trees are able to achieve high leaf efficiency is uncertain. In thi s study, our aim was to investigate the leaf efficiency of branch-cut F. micr ocarpa and F. virens trees, and evaluate the role of leaf efficiency in th e growth of branch-cut trees. The study was conducted in an experimental g arden at the foot of Jinyun Mountain National Nature Reserve (29° 50′ N, 106° 26′ E). Two branch-cutting seasons (spring and autumn) and four branch-cutti ng intensities (0%, 20%, 50%, and 70% reduction of crown depth by removing branc hes) were applied in the experiment. The aboveground biomass of branch-cut tree s instantaneously after cutting as well as one year after cutting was determined indirectly based on the regression formulas constructed with harvested trees. It was shown in the experiment that branch-cutting did not decrease the leaf ef ficiency of both F. microcarpa and F. virens trees. Conversely, the leaf efficiency of F. microcarpa and F. virens trees was increased after bra nch cutting, regardless of the intensity and the season of branch-cutting (exce pt that the leaf efficiency of spring-treated F. microcarpa trees did not a lter too much). It was found that the effects of branch-cutting on the increase of leaf efficiency varied with cutting season. For both species, branch-cuttin g conducted in autumn led to a larger increase in leaf efficiency than that cond ucted in spring. Furthermore, the pattern of leaf efficiency changing with cutti ng intensity differed between cutting seasons. The leaf efficiency of autumn-cu t trees increased with cutting intensity, but the leaf efficiency of spring-cut trees did not present this pattern. The experimental results revealed that incr eased leaf efficiency contributed to the aboveground biomass gain of F. microc arpa and F. virens trees after branch cutting. The proportions of abovegro und biomass gain due to the increase of leaf efficiency to the overall abovegrou nd biomass gain one year after cutting were 7.9%, 12.9%, and 21.6% in 20%, 50%, and 70% autumn-cut F. microcarpa trees; 24.4%, 18.1%, and 15.4% in 20%, 50% , and 70% spring-cut F. virens trees; and 9.5%, 19.9%, 35.3% in 20%, 50%, a nd 70% autumn-cut F. virens trees. Undoubtedly, the increase of leaf effici ency following branch-cutting could, to some extent, alleviate the reduction of photosynthetic assimilate production of branch-cut trees. Raising leaf efficie ncy is a useful strategy of trees to mitigate the adverse effects of external da mages on growth.

The provision of broadband services at a reasonable cost to residential and small business customers is one of the major challenges facing operators. The introduction of cost-effective systems considering the existing infrastructure is an important study. Within the RACE project 2024 Broadband Access Facilities, the economic and evolution aspects of different introduction scenarios of a broadband access system suitable for providing these services are investigated. This paper presents the final results of this study.

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This paper presents a compact low power D-band low noise amplifier (LNA) implemented in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$22-\text{nm}$</tex> fully depleted-silicon-on-insulator (FDSOI) technology. The LNA consists of three differential common source stages with a capacitive neutralization technique. The LNA exhibits a measured peak small signal gain of 16 dB at 130 GHz with a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3-\text{dB}$</tex> bandwidth of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$20 \text{GHz}(121-141 \text{GHz})$</tex>. The measured noise figure (NF) and input 1-dB compression point (IP1dB) are 6.3 dB and −17.5 dBm, respectively. The LNA consumes a total dc power of 22 mW from a single 0.8 V power supply and occupies a die area of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$480 \times 265 \mu \mathrm{m}^{2}$</tex> including the GSG pads.

Within the RACE project 1051 `multigigabit transmission in the IBCN subscriber loop' the major technologies for 5 and 10 Gbit/s fiber-optic transmission systems have been developed. Components and building blocks for all system functions like multiplexer, laser driver, receiver preamplifier, main amplifier, regenerator and demultiplexer/channel selector have been realized in the form of silicon bipolar chips for both bitrates. Integrated transmitter and receiver modules have been built around advanced optoelectronic components. With a cascade of 4 optical amplifiers it was possible to bridge a budget of 100 dB at 10 Gbit/s without applying optical filters. This means that more than 8 million customers can be supplied by only one optical transmitter.

Recent trends towards adopting hypervisors, hierarchical scheduling, and other virtualization technologies that achieve partitioned access to the CPU and other resources impose significant impact with respect to jitter performance in embedded real-time systems. In this paper we make a first step towards characterization, modeling and calculation of this jitter.