Journal of Military Science and Technology

HUMAN ROBOT INTERACTIVE INTENTION PREDICTION USING DEEP LEARNING TECHNIQUES

Thang — 2021-05-10

In this research, we propose a method of human robot interactive intention prediction. The proposed algorithm makes use of a OpenPose library and a Long-short term memory deep learning neural network. The neural network observes the human posture in a time series, then predicts the human interactive intention. We train the deep neural network using dataset generated by us. The experimental results show that, our proposed method is able to predict the human robot interactive intention, providing 92% the accuracy on the testing set.

DETERMINATION OF THE CHARACTERISTICS OF INVERSION REFLECTING LAYERS IN THE TROPOSPHERE ON CHANGES IN THE SIGNAL INTENSITY ON THE NEAR-EARTH OVER-THE-HORIZON ROUTES IN THE MIDDLE LATITUDES

Anh — 2021-05-10

The methodology for determining changes of altitude, elevation velocity, and reflection coefficient of the elevated inversion layer in the troposphere is examined based on the results of observation of VHF signals on over-the-horizon (OTH) routes. Estimations of the elevation velocity and reflection coefficient of the elevated inversion layers on the results of measuring of the levels of VHF signals in the zone of the near geometric shadow in the middle latitudes and the meteorological sounding data using balloons are obtained.

A DESIGN SOLUTION FOR COMPACT SLOTTED WAVEGUIDE ARRAY ANTENNAS BASED ON SIW TECHNOLOGY

Viet — 2021-05-10

Slotted waveguide array antenna is a crucial structure in microwave frequency antennas with many applications in radar and communications systems. Previously, slotted waveguide array antenna systems mainly used metal materials. The study of slotted array antenna based on the waveguided with SIW (Substrate Integrated Waveguide) technology is a novel approach. The paper presents the results of researching, designing, and manufacturing waveguide slot array antenna with low SLL using SIW technology in X-band. The results will be an essential basis for selecting a design solution for slotted waveguide array antenna by SIW technology to replace traditional metal slot array antennas in practical applications in X band radar antenna systems.

RESEARCH AND DEVELOPMENT OF ONLINE-REALTIME SUPERVISING SYSTEM FOR LOW VOLTAGE GRIDS

Duc — 2021-05-10

This paper presents some results of fabrication and experiment of an online-realtime supervising system for low voltage grids. The experiment results show that, for the proposed system, important operating parameters of the low voltage grid such as voltage, current, power, temperatures of oil, cable are supervised and analyzed. Additionally, alarming messages are sent to operators immediately when there are abnormal phenomenon occurring at the grid. This proposed system can help improve reliability of electric supply and reduce SAIDI, SAIFI, as well as enhance safety of human being and equipment.

A WIDEBAND ANTENNA ARRAY FOR RF ENERGY HARVESTING

Thuy — 2021-05-10

In this paper, we introduce a wideband antenna array for RF energy harvesting from 3G/4G and Wi-Fi. The array consists of four parallelly linked wideband antenna elements and a metallic reflector to enhance gain and suppress back lobe radiation. In measurement, the antenna array possesses a wide bandwidth spanning from 1.6 GHz to 2.5 GHz, fully cover the three harvested bands, and the high gains between 13.5 dBi and 14 dBi. The antenna is employed in a multiband rectenna for energy harvesting and placed in the ambience. The rectenna was able to collect up to 0.27 mW power.

STRUCTURE, MORPHOLOGICAL, MAGNETIC AND OPTICAL PROPERTIES OF CuxMg1-xFe2O4 (x = 0, 0.5, 1) NANO FERRITES SYNTHESIZED BY CO-PRECIPITATION METHOD

Chinh — 2021-05-10

Cu_xMg_1.xFe₂O₄ nanoparticles were successfully synthesized by co-precipitation. The samples were calcined at 900 ^oC for 3 h and X-ray diffraction analysis showed that Cu_0.5Mg_0.5Fe₂O₄ had a single phase cubic spinel structure, while formation of secondary phase of Fe₂O₃ was observed in XRD patterns of CuFe₂O₄, MgFe₂O₄. The saturation magnetization (M_s) of Cu_0.5Mg_0.5Fe₂O₄ is in between the saturation magnetization values of CuFe₂O₄ and MgFe₂O₄ nanoparticles, CuFe₂O₄ is a ferromagnetic material, while MgFe₂O₄ and Cu_0.5Mg_0.5Fe₂O₄ show superparamagnetic behavior. The synthesized spinel ferrites were fully characterized using scanning electron microscopy (SEM), FTIR spectroscopy, energy dispersive spectroscopy (EDS) and UV-vis spectrophotometry.

EFFECTS OF ELECTRICAL CURRENT FREQUENCY ON THE PHYSICOCHEMICAL CHARACTERISTICS OF WASTEWATER

Ba — 2021-05-10

Water plays a crucial role in the growth and development of species on Earth. Changes in the physicochemical properties of water have a large effect on human activities as well. Researchers have studied and evaluated the effects of electrical current frequency (f = 0÷2.000 Hz) on the physicochemical properties (surface tension, dynamic viscosity, specific weight) of wastewater. The effect of electric fields on the physicochemical properties of water, allows it to identify the optimal treatment regimes that promote the intensification of various processes taking place in an aqueous medium or in the presence of water.

PARAMETRIC BLIND-DECONVOLUTION METHOD TO REMOVE IMAGE ARTIFACTS IN WAVEFRONT CODING IMAGING SYSTEMS

Nhu — 2021-05-10

Wavefront coding technique includes a phase mask of asymmetric phase mask kind in the pupil plane to extend the depth of field of an imaging system and the digital processing step to obtain the restored final high-quality image. However, the main drawback of wavefront coding technique is image artifacts on the restored final images. In this paper, we proposed a parameter blind-deconvolution method based on maximizing of the variance of the histogram of restored final images that enables to obtain the restored final image with artifact-free over a large range of defocus.

APPLICATION OF MORPHOLOGICAL IMAGE PROCESSING TO REMOVE HAIR NOISES WHILE ENHANCING PATTERNS OF NEAR-INFRARED HUMAN VEIN IMAGES

Thuan — 2021-05-10

Recently, the innovative vein finder system has been studied extensively and has many practical uses in healthcare and security. Developing a better vein finder system often relies on image processing procedures which help to enhance the vein images. Conventional image processing procedures as median filtering and adaptive histogram equalization have shown benefit in enhancing vein patterns. However, in some cases when there are hairs present in the images, most of these procedures are less effective in removing noises from hairs. In this work, we present a new approach employed additional morphological image processing procedures to efficiently remove hair noises. We have successfully constructed a vein finder device to acquire vein images and demonstrate the advantage of our approach. Effects of the size and shape of the structural element in different morphological image processing steps were studied and optimized to achieve the best enhancement effect. Our approach can be applied widely to other vein finder systems and enhance vein images from various parts of the human body.

PERFORMANCE ANALYSIS OF THE SUPERCOMPUTER BASED ON RASPBERRY PI NODES

Hai — 2021-05-10

In this paper, a new Raspberry PI supercomputer cluster architecture is proposed. Generally, to gain speed at petaflops and exaflops, typical modern supercomputers based on 2009-2018 computing technologies must consume between 6 MW and 20 MW of electrical power, almost all of which is converted into heat, requiring high cost for cooling technology and Cooling Towers. The management of heat density has remained a key issue for most centralized supercomputers. In our proposed architecture, supercomputers with highly energy-efficient mobile ARM processors are a new choice as it enables them to address performance, power, and cost issues. With ARM’s recent introduction of its energy-efficient 64-bit CPUs targeting servers, Raspberry Pi cluster module-based supercomputing is now within reach. But how is the performance of supercomputers-based mobile multicore processors? Obtained experimental results reported on the proposed approach indicate the lower electrical power and higher performance in comparison with the previous approaches.

THE DYNAMIC CALCULATION MODEL OF LAUNCHER ON COMBAT VEHICLES USING HYDRAULIC JACKS ON ELASTIC GROUND

Phu — 2021-05-10

In this paper, a dynamics model of a launcher on a combat vehicle using hydraulic jacks is established. Theoretical foundations of multi-object mechanics are used to set up mathematical equations describing the vibration of a launcher when firing. The ground in the surveyed model is considered as an elastic element with K hardness and viscous drag coefficient C. The research results are applied to calculate the BM14 combat vehicle, the stability of the BM14 launcher when single and multiple fired is specifically surveyed in the following cases: Using hydraulic jacks, the ground is considered to be inelastic; Using hydraulic jacks, BM-14 combat vehicle is placed on the elastic ground; Without using hydraulic jacks, BM-14 combat vehicles are placed on the elastic ground. Survey results show the reliability of the launcher when firing. The content of the paper is a theoretical basis to contribute to the process of improvement, design, manufacturing, and exploitation of combat vehicles that use hydraulic jacks with high efficiency.

MODELING AND ANALYSIS OF ABSORPTION PERFORMANCE OF UNDERWATER ANECHOIC LAYERS WITH CAVITIES

Hai — 2021-05-10

Anechoic layer is vital for the underwater acoustic stealth of submarines. This paper develops a simulation-based model for analysis of the acoustic properties of an underwater anechoic layer containing air-filled cavities. First, we present a numerical framework at a relevant scale to implement the acoustical model of an anechoic coating. Then, an investigation of the effects of cavity geometry and elastic property of matrix materials on the absorption property of the anechoic layer is conducted after a validation step. It can be stated from the obtained results that we enable to improve the absorption performance of the considered anechoic coating by tuning its structural factors and mechanical characteristics.

EVALUATION OF THE COAXIALITY OF OPTICAL SYSTEMS WITH LARGE MAGNIFICATION ON BLOCK CAMERAS

Tuan — 2021-05-10

The general tendency of observation weapons is the combination of sensors in one device, allowing multispectral observation devices. This facilitates flexible observation in different space, time and climate conditions. This type of observation devices is often called multispectral observation devices, which can be compact (hand-held) or an observation system. Multispectral observation devices often consist of a daylight channel, a night channel using thermal imaging technology or low light image intensifier systems in combanation with a laser rangefinder module. In this article, the authors suggested a method for surveillance, assessment and application of block cameras with the purpose of manufacturing multispectral observation systems and devices.