Spoofing sources can effectively disrupt a GPS receiver during the acquisition phase by generating multiple false correlation peaks and increasing the noise floor. Such deceptive correlation peaks can mislead the GPS ...
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Spoofing sources can effectively disrupt a GPS receiver during the acquisition phase by generating multiple false correlation peaks and increasing the noise floor. Such deceptive correlation peaks can mislead the GPS receiver into acquiring the spoofer generated signals rather than the authentic signals. Also, the spoofer can increase the receiver noise floor to bury the authentic signals in the noise and at the same time generate correlation peaks with amplitudes commensurate with reasonable c/N0 expectations. The main focus of this paper is on assessment of the reduced effectiveness of the GPS spoofer countermeasure during acquisition where the GPS receiver utilizes c/N0 discrimination. As shown, whereas the c/N0 discrimination is of limited effectiveness, with a modest circuit modification, the receiver can measure the absolute power of the correlation peaks, which is an effective means of detecting and discriminating spoofer sources. It will be shown that employing absolute power monitoring technique considerably reduces the vulnerability region of the receiver compared with the c/N0 monitoring techniques. copyright (c) 2012 John Wiley & Sons, Ltd.
The reasonable control of the dispersion of noble metals is an important topic for heterogeneous catalysts. In this manuscript, Pdcu/c, Aucu/c and PdAucu/c were prepared by the galvanic reduction method to ensure that...
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The reasonable control of the dispersion of noble metals is an important topic for heterogeneous catalysts. In this manuscript, Pdcu/c, Aucu/c and PdAucu/c were prepared by the galvanic reduction method to ensure that Pd and Au follow the distribution of cu nanoparticles. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive spectrometer elemental mappings and lines scans. Both the Pd and Au had very high dispersion no matter whether they were introduced individually or simultaneously. The Pd and Au were distributed mainly on the cu nanoparticles as evidenced by the energy-dispersive spectrometer elemental mappings and lines scans. The reduction of 4-nitrophenol was used as a model reaction for the prepared catalysts. Pdcu/c and Aucu/c showed high activity for this reaction compared to the literature, and the activity could be further increased by the introduction of Pd and Au in an appropriate ratio at the same time. The normalized reaction rate reached 2.005 s(-1) mM(-1) for the PdAucu/c-2.0, in which the mole ratio of Pd to Au was 2.0.
A coaxial electrode structure composed of manganese oxide-decorated Tic/ccore/shell nanofiber arrays is produced hydrothermally in a KMnO4 solution. The pristine Tic/ccore/shell structure prepared on the Ti alloy su...
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A coaxial electrode structure composed of manganese oxide-decorated Tic/ccore/shell nanofiber arrays is produced hydrothermally in a KMnO4 solution. The pristine Tic/ccore/shell structure prepared on the Ti alloy substrate provides the self-sacrificing carbon shell and highly conductive Ticcore, thus greatly simplifying the fabrication process without requiring an additional reduction source and conductive additive. The as-prepared electrode exhibits a high specificcapacitance of 645 F g(-1) at a discharging current density of 1 A g(-1) attributable to the highly conductive Tic/c and amorphous MnO2 shell with fast ion diffusion. In the charging/discharging cycling test, the as-prepared electrode shows high stability and 99% capacity retention after 5000 cycles. Although the thermal treatment conducted on the as-prepared electrode decreases the initial capacitance, the electrode undergoes capacitance recovery through structural transformation from the crystalline cluster to layered birnessite type MnO2 nanosheets as a result of dissolution and further electrodeposition in the cycling. 96.5% of the initial capacitance is retained after 1000 cycles at high charging/discharging current density of 25 A g(-1). This study demonstrates a novel scaffold to construct MnO2 based Scs with high specificcapacitance as well as excellent mechanical and cycling stability boding well for future design of high-performance MnO2-based Scs.
The transcription factor c/EBP is essential for myeloid differentiation and is frequently dysregulated in acute myeloid leukemia. Although studied extensively, the precise regulation of its gene by upstream factors ha...
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The transcription factor c/EBP is essential for myeloid differentiation and is frequently dysregulated in acute myeloid leukemia. Although studied extensively, the precise regulation of its gene by upstream factors has remained largely elusive. Here, we investigated its transcriptional activation during myeloid differentiation. We identified an evolutionarily conserved octameric sequence, cccAGcAG, approximate to 100 bases upstream of the cEBPA transcription start site, and demonstrated through mutational analysis that this sequence is crucial for c/EBP expression. This sequence is present in the genes encoding c/EBP in humans, rodents, chickens, and frogs and is also present in the promoters of other c/EBP family members. We identified that ZNF143, the human homolog of the Xenopus transcriptional activator STAF, specifically binds to this 8-bp sequence to activate c/EBP expression in myeloid cells through a mechanism that is distinct from that observed in liver cells and adipocytes. Altogether, our data suggest that ZNF143 plays an important role in the expression of c/EBP in myeloid cells.
beta-catenin signaling is triggered by WNT proteins and is an important pathway that negatively regulates adipogenesis. However, the mechanisms controlling the expression of WNT proteins during adipogenesis remain inc...
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beta-catenin signaling is triggered by WNT proteins and is an important pathway that negatively regulates adipogenesis. However, the mechanisms controlling the expression of WNT proteins during adipogenesis remain incompletely understood. Lysine demethylase 5A (KDM5A) is a histone demethylase that removes trimethyl (me3) marks from lysine 4 of histone 3 (H3K4) and serves as a general transcriptional corepressor. Here, using the murine 3T3-L1 preadipocyte differentiation model and an array of biochemical approaches, including chIP, immunoprecipitation, RT-qPcR, and immunoblotting assays, we show that Kdm5a is a target gene of ccAAT/enhancer-binding protein (c/EBP), an important early transcription factor required for adipogenesis. We found that c/EBP binds to the Kdm5a gene promoter and transactivates its expression. We also found that siRNA-mediated KDM5A down-regulation inhibits 3T3-L1 preadipocyte differentiation. The KDM5A knockdown significantly up-regulates the negative regulator of adipogenesis Wnt6, having increased levels of the H3K4me3 mark on its promoter. We further observed that WNT6 knockdown significantly rescues adipogenesis inhibited by the KDM5A knockdown. Moreover, we noted that c/EBP negatively regulates Wnt6 expression by binding to the Wnt6 gene promoter and repressing Wnt6 transcription. Further experiments indicated that KDM5A interacts with c/EBP and that their interaction cooperatively inhibits Wnt6 transcription. Of note, c/EBP knockdown impaired the recruitment of KDM5A to the Wnt6 promoter, which had higher H3K4me3 levels. Our results suggest a mechanism involving c/EBP and KDM5A activities that down-regulates the Wnt/-catenin pathway during 3T3-L1 preadipocyte differentiation.
Single instruction, multiple data (SIMD) extensions have been a feature of choice for processor manufacturers for a couple of decades. Designed to provide significant accelerations, they require expertise, the use of ...
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Single instruction, multiple data (SIMD) extensions have been a feature of choice for processor manufacturers for a couple of decades. Designed to provide significant accelerations, they require expertise, the use of potentially fragile compiler support, or vendor-specific libraries. Here, a c++ template library called *** is presented that simplifies the exploitation of SIMD hardware within a standing c++ programming model.
Frama-c is a source code analysis platform that aims at conducting verification of industrial-size c programs. It provides its users with a collection of plug-ins that perform static analysis, deductive verification, ...
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Frama-c is a source code analysis platform that aims at conducting verification of industrial-size c programs. It provides its users with a collection of plug-ins that perform static analysis, deductive verification, and testing, for safety- and security-critical software. collaborative verification across cooperating plug-ins is enabled by their integration on top of a shared kernel and datastructures, and their compliance to a common specification language. This foundational article presents a consolidated view of the platform, its main and composite analyses, and some of its industrial achievements.
This paper presents cMOD, a novel tool that provides a sound module system for c. cMOD works by enforcing a set of four rules that are based on principles of modular reasoning and on current programming practice. cMOD...
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This paper presents cMOD, a novel tool that provides a sound module system for c. cMOD works by enforcing a set of four rules that are based on principles of modular reasoning and on current programming practice. cMOD's rules flesh out the convention that. h header files are module interfaces and. c source files are module implementations. Although this convention is well known, existing explanations of it are incomplete, omitting important subtleties needed for soundness. In contrast, we have formally proven that cMOD's rules enforce both information hiding and type-safe linking. To use cMOD, the programmer develops and builds their software as usual, redirecting the compiler and linker to cMOD's wrappers. We evaluated cMOD by applying it to 30 open source programs, totaling more than one million lines of code. Violations to cMOD's rules revealed more than a thousand information hiding errors, dozens of typing errors, and hundreds of cases that, although not currently bugs, make programming mistakes more likely as the code evolves. At the same time, programs generally adhere to the assumptions underlying cMOD's rules and, so, we could fix rule violations with a modest effort. We conclude that cMOD can effectively support modular programming in c: It soundly enforces type-safe linking and information hiding while being largely compatible with existing practice.
The cyclic ablation resistance of coated carbon/carbon (c/c) composites play crucial roles in their further engineering applications and development due to the cyclic ablation environment accompanied by rapid heating ...
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The cyclic ablation resistance of coated carbon/carbon (c/c) composites play crucial roles in their further engineering applications and development due to the cyclic ablation environment accompanied by rapid heating and cooling and high-speed heat flow scouring, which can reflect the performance stability of the coating. In this research, a (Sic/Hfc)4/Sic (SHS) multi-layer coating was prepared on c/ccomposites. compared with single layer (Sic and Hfccoating) coated sample, the mass and linear ablation rate of SHS coated sample after three ablation cycles (60 s x 3) were only 0.64 mg/s and 0.53 mu m/s, respectively. This is mainly because the introduction of many interfaces inhibits the propagation of cracks, the irregular cracks region only exists in the outer layer. Besides, the oxide layer with dense structure was formed near the c/c substrate, which could prevent oxygen from penetrating into the coating and continue to play a protective role.
Animals' perception and behavior involve integration of multiple sensory modalities. caenorhabditis elegans is a useful model for studying multimodal sensory integration, as it has well-characterized neuronal circ...
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Animals' perception and behavior involve integration of multiple sensory modalities. caenorhabditis elegans is a useful model for studying multimodal sensory integration, as it has well-characterized neuronal circuits in a relatively simple nervous system. However, most studies based on functional imaging have only been conducted on single modal stimuli, because well-controlled multimodal experiments for c. elegans are technically difficult. For instance, no single systems currently deliver precise stimuli with spatial, temporal, and intensity control, despite prior hypotheses that interneurons do integrate these sensory inputs to control behavior. Here, a microfluidic platform that can easily deliver spatially and temporally controlled combination stimuli to c. elegans is presented. With this platform, both sensory and interneuron activity is measured in response to mechanical and chemical stimulations in a quantitative and high-throughput manner. It is found that the activity of command interneuron PVccan be modulated by prior stimulation both within the same and across different modalities. The roles of monoaminergic and peptidergic signaling are further examined on the process of multimodal integration through PVc activity. The approach exemplified here is envisioned to be broadly applicable in different contexts to elucidate underlying mechanisms and identify genes affecting multisensory integration.
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