Engineering with Computers - In this paper, multi-stage continuous belt (MSCB) dryer was used for carrot slices drying. Experiments were performed at three air speeds (1, 1.5, and 2 m/s)... 相似文献
Botnet is a distributed platform for illegal activities severely threaten the security of the Internet. Fortunately, although their complicated nature, bots leave some footprints during the C&C communication that have been utilized by security researchers to design detection mechanisms. Nevertheless, botnet designers are always trying to evade detection systems by leveraging the legitimate P2P protocol as C&C channel or even mimicking legitimate peer‐to‐peer (P2P) behavior. Consequently, detecting P2P botnet in the presence of normal P2P traffic is one of the most challenging issues in network security. However, the resilience of P2P botnet detection systems in the presence of normal P2P traffic is not investigated in most proposed schemes. In this paper, we focused on the footprint as the most essential part of a detection system and presented a taxonomy of footprints utilized in behavioral P2P botnet detection systems. Then, the resilience of mentioned footprints is analyzed using three evaluation scenarios. Our experimental and analytical investigations indicated that the most P2P botnet footprints are not resilient to the presence of legitimate P2P traffic and there is a pressing need to introduce more resilient footprints. 相似文献
Wireless body area networks (WBANs) are deal with wireless networks in the human body. We describe the performance analysis of dual-hop cooperative relaying systems employing amplify-and-forward (AF) technique in WBANs over independent and nonnecessary identically distributed Gamma fading channels. More specifically, we present closed-form derivations of the outage probabilities (OP), symbol error probabilities (SEP) and ergodic capacity (EC) for fixed gain and channel state information (CSI)-assisted relaying techniques at arbitrary signal-to-noise-ratios (SNRs). We also deduce novel expressions in the high SNR region. By doing so, we can quantify the performance of system by the diversity and coding gains. Using the derived expressions as a starting point and for the case of Exponential fading, we consider three practical optimization scenarios. They are optimal relay position with fixed power allocation, power allocation under the fixed location of the relay and joint optimization of power allocation and relay position under a transmit power constraint. The Monte Carlo simulations are used to validate the accuracy of our derivations, where it is demonstrated that the proposed adaptive allocation method significantly outperforms the fixed allocation method.
Debugging—the process of identifying, localizing and fixing bugs—is a key activity in software development. Due to issues such as non-determinism and difficulties of reproducing failures, debugging concurrent software is significantly more challenging than debugging sequential software. A number of methods, models and tools for debugging concurrent and multicore software have been proposed, but the body of work partially lacks a common terminology and a more recent view of the problems to solve. This suggests the need for a classification, and an up-to-date comprehensive overview of the area. This paper presents the results of a systematic mapping study in the field of debugging of concurrent and multicore software in the last decade (2005–2014). The study is guided by two objectives: (1) to summarize the recent publication trends and (2) to clarify current research gaps in the field. Through a multi-stage selection process, we identified 145 relevant papers. Based on these, we summarize the publication trend in the field by showing distribution of publications with respect to year, publication venues, representation of academia and industry, and active research institutes. We also identify research gaps in the field based on attributes such as types of concurrency bugs, types of debugging processes, types of research and research contributions. The main observations from the study are that during the years 2005–2014: (1) there is no focal conference or venue to publish papers in this area; hence, a large variety of conferences and journal venues (90) are used to publish relevant papers in this area; (2) in terms of publication contribution, academia was more active in this area than industry; (3) most publications in the field address the data race bug; (4) bug identification is the most common stage of debugging addressed by articles in the period; (5) there are six types of research approaches found, with solution proposals being the most common one; and (6) the published papers essentially focus on four different types of contributions, with “methods” being the most common type. We can further conclude that there are still quite a number of aspects that are not sufficiently covered in the field, most notably including (1) exploring correction and fixing bugs in terms of debugging process; (2) order violation, suspension and starvation in terms of concurrency bugs; (3) validation and evaluation research in the matter of research type; (4) metric in terms of research contribution. It is clear that the concurrent, parallel and multicore software community needs broader studies in debugging. This systematic mapping study can help direct such efforts. 相似文献
The NW-SE trending Northern Apennine Mountains consist of a series of allochthonous units which were thrust generally to the NE during Neogene crustal shortening, in the direction of a foreland basin to the east andNE. On the hinterland (internal) side of this fold-and-thrust belt, a series of small-scale sedimentary basins developed from the late Miocene and were deformed at the same time. The late Tortonian-Pleistocene evolution of the Northern Apennines has previously been considered by most authors in terms of a classical model of a NE-migrating compressional front, which was followed in time and space by a hinterland extensional regime related to the development of the Tyrrhenian Basin. This paper presents new structural data from both the external parts of the Northern Apennines and the late Tortonian-Pleistocene basins located in the internal sector. In the Northern Apennine thrust belt, reactivation and out-of-sequence geometries for the thrust faults have been recorded. In the hinterland basins, compressional deformation has been documented and is usually associated with thrust ramps and regional unconformities. The timing of both thrust reactivation and of the major compressional phases affecting the hinterland basins is closely correlated with periods of magmatic quiescence, and with compressional phases detected in the external margin of the Northern Apennines (the Padan-Adriatic foredeep). Data presented in this paper indicate that compressional deformation has played a major role in the recent evolution of the Northern Apennines. The mechanism envisaged to explain this tectonic framework takes account of the piggy-back emplacement of basement thrusts from internal to external sectors, which occurred in post-Serravallian time. Activity on basement thrusts may have caused reactivation of thrusts in the internal cover sequence, giving rise to out-of-sequence geometries and controlling the development and/or deformation of the hinterland basins. This type of structural evolution has resulted in a complex geometry for the thrust sheets, and this must be taken into consideration during re-interpretation of the structure of the Northern Apennines. It may also have important implications for petroleum exploration. 相似文献
A new chemical method for fast deposition of electrochromically active thin films of birnessite-type potassium manganese oxide (K0.27MnO2·xH2O) has been developed. The chemical deposition has been performed at room temperature by a reaction of aqueous solutions of potassium permanganate and manganese(II) chloride. The prepared thin films have thickness from 50 to 250 nm depending on the number of the deposition cycles. The composition and the structure of the K-birnessite films are studied by XRD, IR spectroscopy and TG/DTA analyses. Electrochemical studies using four different electrolytes such as aqueous K2SO4, Li2SO4, KNO3, and LiClO4 in PC have been performed. The electrochromic activity has been explored by cyclic voltammetry and VIS spectrometry. The best electrochromic properties are obtained using aqueous KNO3, where the difference in the transmittance at 400 nm between the bleached and colored state is 40% for both as-deposited and annealed films. The obtained data allow the prepared K-birnessite thin films in aqueous KNO3 electrolyte to be proposed as a promising system for electrochromic applications. 相似文献
The first results of the movable electrode biasing experiments performed on the IR-T1 tokamak are presented. For this purpose,
a movable electrode biasing system was designed, constructed, and installed on the IR-T1 tokamak, and then the positive voltage
applied to an electrode inserted inside the tokamak limiter and the plasma current, poloidal and radial components of the
magnetic fields, loop voltage, and diamagnetic flux in the absence and presence of the biased electrode were measured. Results
compared and discussed. 相似文献
This paper describes a solution-based technique for fabrication of varistor grade composite nanopowders. The method consists
of coating major varistor dopants on the surface of the ZnO nanoparticles. As a result, a homogenous mixture of dopants and
ZnO nanoparticles will be achieved. TEM results indicated that a composite layer of dopants with the average particle size
of 9 nm on the surface of ZnO nanoparticles has been successfully prepared. Sintering of the coated powders was performed
in temperatures as low as 850 °C and final specimens with average particle size of 900 nm and density of 98.5% were achieved.
In comparison to conventional mixing, varistors prepared from coated nanopowders exhibited superior electrical properties
and microstructure homogeneity. The improvement of electrical properties can be attributed to small grain size, homogenous
distribution of dopants and elimination of large Bi-Pockets. In addition, the processing route of schottky barrier formation
is quite different from what is generally considered as the method of barrier formation in ZnO grain boundaries. 相似文献