浅谈示波器的选择

伴随电子科技的飞速发展,数字工程师应用比以往更高码速率的信号进行数据传输和设备通信,同时,射频工程师也在考虑手中信号的波形,以便更准确地了解和分析问题所在。大家都需要选用合适的示波器作为信号观察、测试、测量、分析的工具。     

Wireless image transmission using turbo codes and optimal unequal error protection.

A novel image transmission scheme is proposed for the communication of set partitioning in hierarchical trees image streams over wireless channels. The proposed scheme employs turbo codes and Reed-Solomon codes in order to deal effectively with burst errors. An algorithm for the optimal unequal error protection of the compressed bitstream is also proposed and applied in conjunction with an inherently more efficient technique for product code decoding. The resulting scheme is tested for the transmission of images over wireless channels. Experimental evaluation clearly demonstrates the superiority of the proposed transmission system in comparison to well-known robust coding schemes.     

Evaluation of Smart Phones for Remote Control of a Standard Hospital Room

The standard hospital room interface for control of communication and entertainment devices assumes a patient has the ability to hold and press mechanical switches. If the patient does not have these abilities, then the patient must wait for a nurse to walk by the room to ask for help. Mobile devices using the Android and iOS operating systems are compared to accommodate the limitations of a patient for communication and control of the hospital room environment. In order to design an appropriate system, analysis of currently available off-the-shelf technology is performed to find the appropriate configuration that is compatible with the hospital room environment and covers a clear patient need. Evaluation of components for a fully integrated system is shown. Strengths and weaknesses of each technology are discussed. Progress toward an integrated solution on a tablet is provided in the conclusion.     

Road to Next Generation Mobile Networks: An Evolutionary Dynamics Approach

One of the major challenges that mobile operators (MOs) are faced with nowadays is the transition to 4th Generation (4G) mobile communication technologies. The main reason for this lies on the reluctance of MOs to invest in a new technology without being sure about its success. The current paper investigates the decision-making procedures of a MO that wishes to migrate from its current technology type to 4G. Traditionally, the decision of deploying a new technology has been based on the analysis of similar implementations in other countries. However, such approaches can be inefficient and time consuming, as there are discrepancies concerning the technological progress among different countries. To this end, the authors employ evolutionary game theory to model the interactions of the MO’s decisions and the subscribers’ needs, and propose a practical and efficient qualitative model that identifies the circumstances under which the transition towards 4G networking can be facilitated. Specifically, the mathematical foundation of the decision making process is provided and the key role of the charging price and the quality of experience by the subscribers for using 4G connectivity is proven. With the process of 4G deployment still ongoing, this paper aims to present an analysis that can be used supplementary to the decision process of a MO that aims to evolve his network.     

Magnetically controllable gastrointestinal steering of video capsules

Wireless capsule endoscopy (WCE) allows for comfortable video explorations of the gastrointestinal (GI) tract, with special indication for the small bowel. In the other segments of the GI tract also accessible to probe gastroscopy and colonscopy, WCE still exhibits poorer diagnostic efficacy. Its main drawback is the impossibility of controlling the capsule movement, which is randomly driven by peristalsis and gravity. To solve this problem, magnetic maneuvering has recently become a thrust research area. Here, we report the first demonstration of accurate robotic steering and noninvasive 3-D localization of a magnetically enabled sample of the most common video capsule (PillCam, Given Imaging Ltd, Israel) within each of the main regions of the GI tract (esophagus, stomach, small bowel, and colon) in vivo, in a domestic pig model. Moreover, we demonstrate how this is readily achievable with a robotic magnetic navigation system (Niobe, Stereotaxis, Inc, USA) already used for cardiovascular clinical procedures. The capsule was freely and safely moved with omnidirectional steering accuracy of 1°, and was tracked in real time through fluoroscopic imaging, which also allowed for 3-D localization with an error of 1 mm. The accuracy of steering and localization enabled by the Stereotaxis system and its clinical accessibility world wide may allow for immediate and broad usage in this new application. This anticipates magnetically steerable WCE as a near-term reality. The instrumentation should be used with the next generations of video capsules, intrinsically magnetic and capable of real-time optical-image visualization, which are expected to reach the market soon.     

Implementation of a High Throughput 3GPP Turbo Decoder on GPU

Turbo code is a computationally intensive channel code that is widely used in current and upcoming wireless standards. General-purpose graphics processor unit (GPGPU) is a programmable commodity processor that achieves high performance computation power by using many simple cores. In this paper, we present a 3GPP LTE compliant Turbo decoder accelerator that takes advantage of the processing power of GPU to offer fast Turbo decoding throughput. Several techniques are used to improve the performance of the decoder. To fully utilize the computational resources on GPU, our decoder can decode multiple codewords simultaneously, divide the workload for a single codeword across multiple cores, and pack multiple codewords to fit the single instruction multiple data (SIMD) instruction width. In addition, we use shared memory judiciously to enable hundreds of concurrent multiple threads while keeping frequently used data local to keep memory access fast. To improve efficiency of the decoder in the high SNR regime, we also present a low complexity early termination scheme based on average extrinsic LLR statistics. Finally, we examine how different workload partitioning choices affect the error correction performance and the decoder throughput.     

Effects of the application of fertilisers and trace elements on the cobalt content of herbage cut for conservation

The effects of the application of fertilisers, especially N and trace elements, on the content of Co in mixed grassland herbage and its main constituent species, have been studied. Data have been obtained from field experiments on three mineral soils and on a deep acid peat. The herbage was cut at the silage stage of growth three or four times a year for at least three successive years. Without added Co, N applications increased Co content in herbage on peat but reduced it on mineral soils mainly by eliminating clover which had a higher Co content than grasses. Applying 0.5 kg ha^?1 Co as cobalt sulphate increased herbage Co content, the increase being greater on peat than on mineral soils. These increased levels were unaffected by N applications on mineral soils but were further increased by applied N on peat. The number of years during which the Co additions were effective in producing herbage containing at least 0.1 mg Co kg^?1 dry matter varied on the different soils, ranging from barely three years on one mineral soil to over five years on peat. Without added Co the last cuts in October usually had the highest Co content and the first cuts in June the lowest. With added Co, the seasonal effects were more variable, but the Co content in the herbage frequently decreased from the first to the last cuts.     

Determination ofN-nitrosodiethanolamine in cosmetics and in alkanolamines: results of collaborative studies

Summary Results of collaborative studies on methods for determination ofN-Nitrosodiethanolamine (NDELA), in cosmetics and in alkanolamines are reported. Participants from eleven laboratories in each study examined two freshly prepared model cosmetics, one emulsion and one shower gel and also one sample of triethanolamine. Samples were analyzed unspiked and after fortification with 50 g/kg NDELA. Distribution of unspiked and spiked samples and amounts of NDELA added were not known to the participants. In spiked samples overall mean values (±standard deviation) found for NDELA were 50 ± 9 gg/kg for the emulsion, 53 ± 8 gg/kg for the shower gel and 47 ± 10 g/kg for triethanolamine. With few exceptions, NDELA was not found in unspiked samples at concentrations exceeding the determination limit (10 gg/kg).

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Ergebnisse von Ringversuchen zur Bestimmung vonN-Nitrosodiethanolamin in Cosmetica und in Alkanolaminen

Zusammenfassung Ergebnisse von Ringversuchen zur Bestimmung vonN-Nitrosodiethanolamin (NDELA) in kosmetischen Mitteln and in Alkanolaminen werden beschrieben. Teilnehmer aus jeweils elf Laboratorien analysierten zwei kosmetische Mittel, die für diese Studie frisch hergestellt wurden, eine Emulsion und ein Duschbad Bowie eine Probe Triethanolamin. Die Proben wurden undotiert Bowie nach Zusatz von jeweils 50 g/kg NDELA untersucht, wobei die Verteilung und Höhe der Dotierung den Teilnehmern nicht bekannt wares. Die Gesamtmittelwerte betrugen für die dotierte Emulsion 50 g/kg NDELA±9 g/kg SD (Standardabweichung), für das dotierte Duschbad 53 g/kg NDELA±8 g/kg SD and fur das dotierte Triethanolamin 47 g/kg NDELA ± 10 g/kg SD. Mit wenigen Ausnahmen wurden in den undotierten Proben keine NDELA-Gehalte gefunden, die die Bestimmungsgrenze von 10 g/kg überschritten.

     

Changes in dry matter concentration gradients in stored apples

Longitudinal and transverse dry matter concentration gradients were measured in Cox's Orange Pippin apples at harvest and during storage. Dry matter concentration was higher at the calyx end of the fruit at harvest than in the central zone and at the stalk end. This difference was maintained as dry matter concentration in the whole fruit declined during cold storage. Dry matter concentration decreased from the peel to the core in median transverse slices at harvest but this gradient diminished during storage at 4°C in either air or 1·25%v/v O₂. After 11 weeks' storage dry matter concentrations became generally lower in all zones of the air-stored fruit than those in apples stored in 1·25% v/v O₂, but transverse distribution patterns of dry matter were similar in apples in either regime throughout storage. Proportions of dry matter in the outer zones declined whilst those in the inner cortex and core increased. The relevance of these changes to the quality of stored apples is discussed.