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Short-wave radio is an indispensable long-distance means of communication, among which Morse signals, which rely on simplicity and efficiency, plays an import role in military and civilian applications. Automatic Morse detection and recognition have been researched for several years, but some thorny problems in actual communication always restrict the performance of methods. In this article, by introducing deep learning technology, we propose a network named MorseNet that can simultaneously locate and decode Morse signals in the spectrogram. MorseNet uses shared convolutions to extract shared features for both the detection and recognition branches. The detection branch regresses bounding boxes based on signal centerlines, and the recognition branch decodes Morse fragments cropped from feature maps by a convolutional recurrent neural network (CRNN). The losses of two branches are combined to implement the end-to-end training. Experimental results on four “simulated Morse + real background” datasets demonstrate that the proposed method achieves state-of-the-art performance in both detection and recognition, and it effectively improves four problems that have long been troublesome in accomplishing the tasks. Furthermore, the joint training strategy and architecture give MorseNet advantages over its two-stage deployment in terms of accuracy, speed, and model size.

GPS (global positioning system) signals are direct-sequence spread-spectrum signals. The receiver relies on locally reproduced pseudo-random codes to keep tracking and dispreading the navigation signals. Due to the correlation characteristics of pseudo-random codes, scholars generally believe that only two identical signals that are separated by half a chip error have correlation, which brings high time synchronization accuracy requirements to GPS spoofing technology. In this paper, the research and analysis of the principle of the GPS receiver are carried out. It is found that the GPS spoofing technology can achieve a signal time synchronization error of 1.5 chips and proposed that the correlation peak loss due to chip error can be compensated by the transmit power in the meantime. The detailed theoretical derivation proof is given in the article. Finally, simulation experiments are performed to obtain the minimum spoofing power. The results show that under this error condition, GPS spoofing can be effectively implemented.

Rapid diagnosis of sepsis assists clinicians to initiate timely antibiotic therapy and therefore reduce mortality of bacterial infections. In this work, we presented an integrated microfluidic system for fast isolation of bacteria for both gram-positive and gram-negative bacteria directly from human whole blood, which will be crucial in the detection of sepsis. First, a deterministic lateral displacement (DLD) device was used for sample pretreatment of whole blood, which performed continuous separation of leukocytes, erythrocytes and bacteria. With this approach, most of the blood cells were removed while bacteria and platelets were collected. Then the isolated bacteria were captured with magnetic beads surface-coated with flexible neck regions of mannose-binding lectin (FcMBL) using a new 3D micromixer. The entire process including sample pretreatment and bacteria isolation could be completed on an integrated microfluidic system within 2 hours, which is significantly less than the one for the traditional method (i.e. 3 days). This is the first time that an integrated microfluidic system capable of detecting bacteria by using FcMBL was reported, which may provide a promising way to diagnose sepsis.

This study reported a portable microfluidic system which can be used to automatically perform antibiotic screening with single antibiotic, double antibiotic combinations and even triple antibiotic combinations on clinically isolated bacteria strains. With the incorporation of the integrated pneumatically-driven microfluidic chip, a pneumatic control module, a temperature control module, and an optical detection module, the developed system was capable of achieving significant improvement of operation flexibility as well as cost reduction for determination of antimicrobial susceptibility test and the efficacy of drug combinations via colorimetric results within 4 hours. Personalized antibiotic screening may be realized by using the developed microfluidic system for rapid clinical decision-making.

Protocol format reverse engineering aims to extract the protocol fields automatically without access to the protocol specification. Existing works focus on the methodology of deriving the protocol format efficiently, but neglect the relationship between the statistical characteristics of protocol data and the intrinsic properties of the protocol format. In this paper, we study two problems to see how the protocol specification affects the statistical properties, and how the latter affect the difficulty of format reverse analysis. Through empirical analysis of known protocols, we first verify the stationarity of protocol features, which is the stand for developing trace-based reverse methods. We study the position arrangement and value distribution of protocol fields, and investigate their influence on the statistical properties of the protocol format. Then we propose an HMP-based model of protocol data. Using this model, we define two quantitative indicators by protocol fields' structure and content to reflect the reversibility of protocol format: the field non-interlacing ratio and the field information variation. We apply the analysis of format reversibility to a number of typical realistic protocols. The results suggest that the fields of most protocols can be partially revealed, but there are also certain fields difficult for reverse analysis. The quantitative results can provide hints for improving protocol reverse engineering approaches.

An integrated microfluidic system was developed to identify bacteria in human joint fluid (HJF) in this study. The entire process including bacteria isolation in HJF, bacteria lysis, polymerase chain reaction (PCR) and optical detection could be automated on a single chip. An universal 16S rRNA primer set and four designed primers to identify Staphylococcus aureus (SA), methicillin-resistance Staphylocuccus aureus (MRSA), Escherichia coli (E. coli), and Acinetobacter baumannii $(\pmb{A}.\pmb{B}.)$ were used for bacteria identification. In addition, N-acetyl-L-cysteine for dissolving sticky mucus of HJF samples and vancomycin-coated magnetic beads were applied for bacteria isolation such that the detection limit could be significantly improved. The entire process could be automated by using a microfluidic system. Experimental results showed that the limit of detection (LOD) could be significantly improved to 100 colony formation units (CFU) per milliliter (or 20 CFU/reaction), which meets the demand on clinical diagnosis. Furthermore, the whole process could be performed within 90 minutes, which is much faster when compared to the traditional method (usually 3–7 days).

This study presented an integrated microfluidic device which can perform rapid antimicrobial susceptibility tests (AST) of antibiotics combination against clinical bacteria. A new approach to measure either drug interactions of three antibiotics or minimum inhibitory concentration (MIC) of antibiotics by performing bacteria dispensation and antibiotics dilution automatically was proposed and it substantially reduced detection time (from 24 hr to 4 hr) and bacteria consumption (from 100 μL to 3 μL) when compared to the broth microdilution method. A new membrane-type micromixer composed of two circular micropumps was integrated in order to achieve on-chip pumping/mixing with high accuracy and efficiency. Experimental results revealed that the proposed device can produce accurate liquid transportation and chaotic mixing and visually interpret AST results including individual MIC determination and drug interactions. Synergistic and antagonistic effects of pairwise and triple interactions among three common antibiotics (vancomycin, gentamicin and ceftazidime) with ten different combinations were demonstrated on one clinical isolate of vancomycin-intermediate staphylococcus aureus. It is the first time that a microfluidic device was demonstrated for drug screening to inhibit bacteria growth with three antibiotics by performing AST automatically. The developed device could be utilized as a robust tool to rapidly explore drug screening for drug cocktail therapy.

A simple microfluidic device which can perform antimicrobial susceptibility testing (AST) of combined antibiotics against antibiotics-resistant bacteria has been presented. A new approach to determine the fractional inhibitory concentration (FIC) index of two antibiotics by performing broth dilutions automatically was proposed and its performance was highly consistent with manual operation. The experimental results showed that the developed device could achieve on-chip dispensation/dilution/mixing accurately and interpret AST results visually. A test using two common antibiotics (vancomycin and ceftazidime) was performed on one clinical isolate of vancomycin-intermediate Staphylococcus aureus (VISA) based on the FIC indices. It is the first time that a microfluidic device was demonstrated to be capable of determining the FIC index of combined antibiotics against bacteria by performing AST automatically. With its high flexibility and reliability, the proposed device provides a simple method to explore drug cocktails for combined antibiotic therapy.

Digital loop-mediated amplification (LAMP) is an isothermal, quantitative DNA amplification approach which has high sensitivity and specificity and could be used to analyze extremely low amount of DNA within a short period of time. In this study, an integrated self-driven microfluidic chip was proposed herein for performing a digital LAMP process for vancomycin-resistant Enterococcus (VRE) diagnosis. The entire bacterial diagnosis could be automatically performed by capillary forces through the new polydimethylsiloxane (PDMS) surface treatment without using external pumps. Moreover, digitized droplets could be separated from each other by normally-close valves such that it could be quantitated. The contact angle of the treated PDMS surface was measured to be only 24°, which was the lowest value in literatures. This is the first time that a rapid (within 1 hour), simple, and hydrophilic PDMS surface modification method has been reported, which could be used in self-driven microfluidic devices for digital LAMP. This device may become a promising tool for clinical diagnosis and point-of-care applications.

This study presents an integrated microfluidic system which can identify the vancomycin resistant gene (vanA) from live hetero-bacteria automatically. In this study, a new approach to diagnose the vanA gene from live hetero-bacteria by using ethidium monoazide (EMA) and loop-mediated isothermal amplification (LAMP) was proposed and its feasibility was tested and verified. In addition, an integrated microfluidic system including a microfluidic chip and a home-made control system was also demonstrated. The experimental results showed that the developed system can detect the vanA gene from “live” Enterococcus but not “dead” Enterococcus successfully with a detection limit of 10 colony formation units (CFU). The entire process including the sample pre-treatment process could be automated within 1 hour. This is the first time that an integrated microfluidic system was demonstrated to diagnose the vanA gene from live bacteria by using a molecular diagnosis approach. With its high sensitivity and accuracy, the proposed system may be promising to verify antibiotic resistance genes from live hetero-bacteria which cannot be achieved by using the existing diagnostic methods.

This paper presents two algorithms to recover LDPC codes in an error-free environment. Both algorithms reconstruct the sparse parity-check matrices of LDPC codes based on elementary row transformation, and are equivalent to recognize LDPC codes. The first one is appropriate to the LDPC codes whose parity-check matrices have the double-diagonal structure; the second one is a general algorithm that ensures the second-best solution for every type of LDPC codes. Simulation results show that, these algorithms work well with most of LDPC standards and protocols, including 802.16e, 802.11n, DVB-S2 GJB7296 and GB20600.

Aiming at the problem of features instability in specific emitter identification, this paper presents a based on one-class classifier feature preprocessing algorithm to detect the unstable features. The algorithm takes advantage of one-class classifier of property that can describe the distribution of given data sets. Its basic steps include: Firstly, we divide the feature time series into N segments with given length; secondly selecting one segment trains one-class classifier acquiring classification surface, and then remaining N-1 segments test the classifier and record the test accurate rates for every segments; finally we compare the minimize of test results with the setting threshold. If the minimize of test rate is lower than threshold in the test segments, we consider the feature is unstable. For a given set of data, experimental results show that the method is effective on determining the feature of stability.

This contribution derives the Cramer-Rao lower bound (CRB) related to the joint estimation of the time delay, the carrier phase, and the frequency offset from a noisy linearly modulated burst signal, containing random data symbols (DS) as well as known pilot symbols (PS). This bound indicates that it is potentially more accurate than the bound which is derived from a burst without PS or limited number of PS only. Further, a new kind of iterative Soft-Decision Directed estimator combined PS initialization is Presented, which performs closely to the derived CRB, and provides a large improvement over the classic Non-Data-Aided or Decision-Directed estimator especially at low and moderate Signal-to-Noise Ratio.

In order to investigate hypoglycemic effects of Momordica charantia(MC) leaves saponins, saponins with purity of 86.0% were extracted from leaves of MC. The extracts were used to treat hyperglycemic rats and the damaged insulinoma cell RIN-M5F in vitro. The effects of MC leaves extracts on the metabolic parameters (serum glucose, insulin, glycogen, Superoxide Dismutase(SOD) activity and Malonedialdehyde (MDA) levels of hyperglycemic rats and the effects on RIN-M5F cells were observed. The results showed that there was a significant increase in serum insulin and glycogen, accompanied by a decrease in serum glucose and MDA in treated rats with MC leaves saponins. And the extracts also exhibited obvious protection and repairation effects on RIN-M5F cells.

Subsidy for purchasing agricultural machinery in many developed countries showed the periodic characteristic. In order to learn their experiences, trace the laws for the financial support of China, provide theoretical support in policy making in developing countries. The characters of subsidy for purchasing agricultural machinery in China have been analyzed in this paper. There are three stages of the central financial subsidy since 2004 when the policy came into effect, including the initial stage, growth stage and maturity stage. The speed of increasing is slow, high and stable respectively in the three stages and the growth curve is approximately "S-shape". After analyzing the typical characters of the investment scale, implement region, subsidized machinery types and subsidized groups, the subsidy for purchasing agricultural machinery is forecasted by Life Cycle Theory and Logistic Growth Model. The result shows that central financial subsidies are expected to total about 97 billion RMB from 2011 to 2015. And it will reach 19.8 billion RMB in 2015.

Fresnel holography is an important branch of holographic display fields, at present, it includes lots of problem to be solved. For revealing the imaging laws of Fresnel holography, the generation and display theory of Fresnel hologram was analyzed in the paper. By analyzing Fresnel diffraction formula and theory and the relation between them and Fresnel holography, for the first time the second imaging phenomenon of Fresnel holographic display via a digital micromirror device (DMD) display system was correctly explained.