Conventional wireless communication schemes indiscriminately transmit information into the whole space and pose inherent security risks. Recently, directional modulation (DIM) has attracted enormous attention as a promising technology. DIM generates correct constellation symbols in desired directions distorts them undesired directions, thus ensuring of transmitted information. Although several have been reported, they suffer from defects bulkiness, energy consumption, high cost, inability to...

Abstract Component allocation in printed circuit card assembly systems is a special case of the classical mixed-model line balancing problem and involves assigning component types to machines achieve specific production objectives. In this paper considered for scenario where there are two or more placement (possibly nonidentical) objective balance, every type, combination time machine setup time. A mathematical formulation developed class machines. Two alternative solution approaches...

In this paper, the method for measuring complex permittivity of concrete has been proposed, and using is measured. This calculating dielectric constant used by deflection loss electromagnetic wave in block experiments. The device a single frequency radar. Measurement process divided into three steps: attenuation factor alpha concrete, refractive index concrete. simple feasible practice.

GIS equipment disconnector is the valve of power system, and its mechanical vibration defect a key factor that threatens safe operation grid. Based on platform, this paper carried out simulation defects in different contact states, compared analyzed evolution law time-frequency domain map under combined action load currents severity defects. The results show response amplitude when poor significantly larger than normal state. As increases, frequency band gradually widens, there clear...

The mechanical defects of gas-insulated switchgear (GIS) equipments seriously threaten their safe and stable operation, but there are detection problems such as latency weak vibration response, especially for high-capacity GIS with large size. In this paper, a novel defect simulation method based on current excitation variable frequency is proposed to solve problem. First, 500 kV system loading capacity was designed by structural parameter adjustment, power matching harmonic suppression the...

GIS(Gas Insulated Switchgear) equipment is one of the most important in power system, which plays an role safe and stable operation grid. In addition to electrical fault, mechanical fault also main reasons endangering equipment, vibration detection a fast, effective accurate method detect quantify defects GIS equipment. Therefore, this paper first developed set portable for Then, with abnormal noise was carried out. Finally, signals different measuring points, distance degree were compared...

Reversible watermark is a kind of fragile watermark, and any changes will lead to the change or loss watermarking information. The modified sensitivity reversible can be used for integrity verification grid map. When content carrier data suspected, type manipulation attack suffered judged through extracting situation. algorithm proposed by this paper aims at characteristics map, reduce impact low correlation adjacent pixels, pixel values are distributed more intensively after disposal...

Mechanical vibration fault is one of the main causes GIS equipment accidents. The current research mainly focuses on characteristics isolation switch under defect inadequate travel or loose busbar, but there still a lack comprehensive comparison different types defects and severity. Therefore, 500kV mechanical test platform was built in this paper to obtain severity such as switch, busbar contact seat shielding cover amplitude injection. results show that normal conditions, signal shell...

In this paper, a novel electrode abrading technique is designed to improve the conventional methods. By employing new depassivation method, 316L stainless steel has been tested in 0.05M H2SO4 solution with and without chloride ion. The repassivation kinetics analysed terms of current density flowing through abraded surface bare metal surfaces. results are described by linear relationship log i(t) versus t. At potentials within passive region, film grew according high field ion conduction...

The propagation of high-frequency electromagnetic plane wave in the dielectric is complex, and energy distribution uneven after scattering. Aimed at these problems, (microwave) researched this paper by finite element software ANSYS. scattering results are obtained establishing solving three models concrete, steel bar - concrete air. There a phenomenon that has concentrative band structure. will scatter fiercely if it placed region dielectric. Several examples shown paper, steps issues which...

One common and traditional method of detecting stored-grain deterioration is by measuring grain temperature. The key to temperature measurement acoustic travel-time measurement. In this paper, a phase transform generalized cross correlation with wavelet (WT-PHAT-GCC) for proposed. An experimental system estimation has been realized. Acoustic travel-times in soybeans air have estimated PHAT-GCC WT-PHAT-GCC respectively. results show that the proportional distance between two microphones. can...

The Bridges had collapsed accidents in recent years due to bridges quality problems. Therefore, concretes nondestructive testing are particularly important. At present, most applications Ground Penetrating Radar (GPR) technology the detection of reinforced structure. GPR used pulse method which alongside with definitive advantages, but internal structure small thickness has very low resolution by this method. In paper, it's first time use ultra-wideband (UWB) stepped frequency conversion...

the reliability and vibration performance test of vibratory rollers have been done in field to ensure that roller meet quality requirement. At present, indoor stand for has not yet studied at home abroad. This paper designs makes simulation analysis by numerical model vibration-drum stand. The isolation system is determined as a function mass (m 2 ), stiffness rubber tire (k 1 ) block ). results showed drum-test can account system.

The problem of target detection which is affected by the direct wave discussed in this paper. Singular Value Decomposition method proposed for removing wave. echo signal decomposed use and one-order eigenvalue matrix set to zero, then related components are removed. can be removed effectively using method, most preserved process signal. HFSS simulation software used modeling simulation, results show that resolution false increases 11% compared with Interference Canceling

Since the importance of ship-radiated noise simulation in onshore training and digital sonar development, we establish a mathematical model on basis analyzing causes characteristics for each its components, then apply simulating signal component turn. Additionally, improving versatility while reducing complexity simulation, design method specific frequency response filter based window function is used to realize simulation. The results demonstrate effectiveness approach.

Removing interferential noise of ground-penetrating radar(GPR) from the echo signal can accurately get information underground targets. Raw data reading is a critical step for GPR processing. In this paper, structure RIS-K2 analyzed. Some C++ programs have been written to read raw and sampling points in form decimal are obtained. Then, analyzed processed with wavelet algorithm MATLAB. The results show that be effectively removed denoising method, it helpful determine targets

This paper present mechanism analysis of the vibration and noise hydraulic system dangers equipment measurement to prevent reduce combining with structure character precision grinder. These measuring will improve hazards equipment. method would system, which provides a propounding base has positive far-reaching significance for development technology.