Performance of Uplink NOMA with User Mobility Under Short Packet Transmission

Wireless Personal Communications - The scenario of an uplink two-user non-orthogonal multiple access (NOMA) communication system is analytically studied when it operates in the short packet...     

Efficient high-performance implementation of JPEG-LS encoder

A new design approach to create an efficient high-performance JPEG-LS encoder is proposed in this paper. The proposed implementation compresses the image data with the lossless mode of JPEG-LS. When the acquisition of precious content (image) is specified to occur in real-time, then lossless compression is essential. Lossless compression is important to critical applications, such as the acquisition of medical images and transmission of high-definition high-resolution images from space (satellite). The contribution of the paper is to introduce an efficient pipelined JPEG-LS encoder, which requires significantly lower encoding time than any other available JPEG-LS hardware or software implementation. The experimental results show that encoding is performed as expected in high-speed, being able to serve real-time applications. This is the first time that a JPEG-LS implementation offers such a high-speed encoding.

Communication and interaction strategies in automotive adaptive interfaces

Nowadays, drivers have to cope with a growing amount of information coming from on-board information messages, telematics and advanced driver assistance systems. The interaction between the driver and these systems is critical, since they may distract the driver from the primary task of driving. The paper, addressing this problem, aims at presenting the methodological framework for the optimization of human machine interfaces (HMI) in the automotive research area; thus, the proper communication and interaction strategies are designed, in order to deliver to the driver a message or a warning in the optimal way in terms of driver safety. The proposed methodology is adopted in the COMUNICAR project and relevant results are presented. Last but not the least, the AIDE integrated project and its vision is also proposed as the roadmap for future activities in the HMI sector.

A1H NMR anomaly for steroidal alcohols? Reactions of a steroidal γ-ketoacid

The chemical and spectroscopic properties of several reaction products of 17β-hydroxy-1,3-seco-2-nor-5α-estran-1-oic acid and 17β-hydroxy-1,3-seco-2-nor-4-oxo-5α-estran-1-oic acid were examined and found to be atypical. For instance, the methyl ester of the first acid was resistant to basic hydrolysis conditions but partly hydrolyzed with 100% H₂SO₄. Reduction of the ester by LiA1H₄ gave 1,3-seco-2-nor-5α-estrane-1,17β-diol from which diacetate, ditosylate and 17-monotosylate derivatives were prepared. The C-1 methylene protons of each appeared as a singlet in 60, 100 and/or 270 MHz NMR spectra. The methyl ester and the diacetate of the diol were synthesized by alternate methods to verify the assigned structures. A 470-MHz spectrum eventually resolved the C-1 methylene protons of the monotysylate into the AB portion of an ABX pattern, further confirming the assigned structures. Also, 2,3-seco-1-oxo-5α-estran-17β-ol 17-nitrate was synthesized.     

Inhibition by cardiolipins of platelet-activating factor-induced rabbit platelet activation

Evidence is presented that cardiolipin, a naturally occurring phospholipid, inhibits the aggregatory effect of platelet-activating factor (paf) on rabbit plateletsin vitro. Bovine heart cardiolipin was shown to inhibit the aggregation of washed rabbit platelets induced by 1×10⁻¹⁰ M and 2×10⁻¹⁰ M paf with IC₅₀ values (doses for half-maximal inhibition) of 8.4±0.8×10⁻⁷ M and 2.6±0.6×10⁻⁶ M, respectively. Phosphonocardiolipin was also able to inhibit platelet aggregation induced by 1× 10⁻¹⁰ M paf with an IC₅₀ value of 3±1×10⁻⁷M. Both compounds, in concentrations up to 1×10⁻⁵ M, were unable to aggregate washed rabbit platelets and failed to inhibit the aggregation induced by 0.9 and 1.8 μM adenosine diphosphate or 0.2–1.0 μM arrchidonic acid. By contrast, the acetylated derivative of cardiolipin exerted an aggregatory effect on aspirin-treated rabbit platelets in the presence of creatine phosphate/creatine phosphokinase. This aggregation was inhibited by the specific paf antagonists BN 52021 and WEB 2086. Also, platelets treated with acetyl-cardiolipin were insensitive to the aggregatory effect of paf. Phosphatidic acid, phosphatidylglycerol,bis(dipalmitoylglycero)phosphate and their phosphono analogues were totally inactive. Similar data were obtained when platelet-rich plasma was used instead of washed rabbit platelets. Our results support the hypothesis that the effect of cardiolipin is mediated through specific paf receptors that act on the rabbit platelet membrane.     

A framework for fuzzy expert system creation--application to cardiovascular diseases.

A methodology for the automated development of fuzzy expert systems is presented. The idea is to start with a crisp model described by crisp rules and then transform them into a set of fuzzy rules, thus creating a fuzzy model. The adjustment of the model's parameters is performed via a stochastic global optimization procedure. The proposed methodology is tested by applying it to problems related to cardiovascular diseases, such as automated arrhythmic beat classification and automated ischemic beat classification, which, besides being well-known benchmarks, are of particular interest due to their obvious medical diagnostic importance. For both problems, the initial set of rules was determined by expert cardiologists, and the MIT-BIH arrhythmia database and the European ST-T database are used for optimizing the fuzzy model's parameters and evaluating the fuzzy expert system. In both cases, the results indicate an escalation of the performance from the simple initial crisp model to the more sophisticated fuzzy models, proving the scientific added value of the proposed framework. Also, the ability to interpret the decisions of the created fuzzy expert systems is a major advantage compared to "black box" approaches, such as neural networks and other techniques.     

Oil Transport in Surf Zone

Oil transport subjected to nearshore currents in the surf zone is considered using the mass conservation equation. Analytical solutions are obtained that describe the longshore distribution of oil deposition, as well as the length of the shoreline contaminated by oil slicks transported in the nearshore environment. The solutions are related to the characteristic longshore and onshore velocities, which are evaluated separately, and oil-holding capacity of the shoreline. The analysis also shows that the distribution of oil deposition varies due to the re-entrainment. Sample computations for typical shoreline types are provided to illustrate the effect of oil-holding capacity. Finally, the limitations of the analytical results are discussed.     

Metal iris influence on guided-mode diffraction

The effects of the presence of metal irises on guided-mode propagation through a symmetrical three-layer slab waveguide are examined by using the integral equation method. The aperture electric field distribution is expressed in terms of a finite series of Chebyshev polynomials. The modal reflection and transmission coefficients, the near-field structure, and the far-field radiation pattern are calculated, while numerical results are presented for several iris apertures.     

Evaluation of passenger train car materials in the cone calorimeter

Recent advances in fire test methods and hazard analysis techniques make it useful to re‐examine passenger train fire safety requirements. The use of test methods based on heat release rate (HRR), incorporated with fire modelling and hazard analysis, could permit the assessment of potential hazards under realistic fire conditions. The results of research directed at the evaluation of passenger train car interior materials in the cone calorimeter are presented. These measurements provide data necessary for fire modelling as well as quantitative data that can be used to evaluate the performance of component materials and assemblies. The cone calorimeter test data were also compared with test data resulting from individual bench‐test methods specified in the FRA fire safety guidelines. The majority of the tested materials which meet the current FRA guidelines show comparable performance in the cone calorimeter. Copyright © 1999 John Wiley & Sons, Ltd.