ISAS 2019: Papers with Abstracts

Abstract. The mixing of hard inclusions into materials is one way to strengthen and increase the durability of the materials, creating granular composite materials. However, apart from the hard inclusions in material, other impurities (soft inclusions) and holes still have the ability to appear and affect the durability of the material. The existence of holes, impurities will affect the behavior of the crack. In this paper, the authors will investigate the effects of holes, hard inclusions, soft inclusions on the behavior of crack when growing under the effect of dynamic loads by extended twice-interpolation finite element method-XTFEM. The results of the dynamic stress intensity factor obtained from numerical examples will clearly show the impact of different types of particles on cracks... The results obtained by XTFEM will be compared with the results published in a prestigious international scientific journal to verify reliability.

Abstract. In biological tissue, there are different kinds of endogenous chromophores. Their absorption spectra in the optical range are sensitive to the physiological change of the animal body. In the near-infrared region (700-1200 nm wavelength), hemoglobin has a characteristic absorption spectrum which is dependent on its redox state. Therefore, the functional information inside the animal body could be obtained noninvasively by measuring the transmitted light. By detecting the change of the absorption characteristics of the animal body, the functional change inside the body can be detected in a two-dimensional transillumination image. In this paper, we propose preliminary research on developing a novel imaging modality of biological body parts. Using the two-dimensional images obtained in many different orientations, three-dimensional physiological function imaging of the biological body by transillumination could be expected. This paper presents a preliminary result in the experiment to show the feasibility of this technique.

Abstract. Burns are one of the most devastating conditions encountered in medicine. This injury is in skin or other tissues, caused by heat-cold, electricity or chemicals [1,2]. There are lots of methods to treat burns and each method has its own advantages, such as medicine, dressing, low-level laser, plasma, skin graft surgery... [3].
This study experimented with the 3rd degree burn model in mice by heat, treating by DBD plasma, is a non-invasive treatment and using clinical diagnostic methods by (1) normal image, (2) thermal image, (3) HE staining. Aim of this research is evaluation and comparison the area, temperature and wound healing time of non-invasive treatment with DBD plasma and nontreatment. After 3-week experiment, using diagnostic methods and analysis tools have demonstrated that the 3rd thermal burn wound healing of plasma treatment recovers faster than non-treatment about: (1) Burn wound surface shrinkage rate is higher: ~ 5%; (2) Healing time is faster: 2-3 days; (3) The average temperature of the burn wound is lower: 1-2oC. Therefore, DBD plasma is a potential treatment in burns wound and wound healing in the future. Keywords: DBD plasma, burn wound, healing wound

Abstract. This present work aims to reduce the color of biodiesel from crude palm oil through the application of activated carbon prepared from chili stem waste. Chilli stem was converted into activated carbon using 30 wt% KOH at a ratio of 1:2 for 1 h, followed by carbonization at 500 oC under an N2 atmosphere for a further hour. Physico-chemical characteristics of the raw material and activated carbon were analyzed including thermogravimetric analysis, proximate analysis, and porosities. The results demonstrated that the activated carbon was a porous material with a highly mesoporous structure (84.5%). The surface area of activated carbon was 10.6 m2/g and it exhibited an average pore diameter of 27.25 nm which was suitable for the removal of large highly colored molecules. Batch adsorption experiments were performed to investigate the reduction in color of the biodiesel. Ratios of activated carbon to biodiesel of 0.002 and 0.1 w/v were used in the study. For comparison, the adsorption was also tested against a commercial activated carbon with a surface area of 1,130 m2/g, but lower average pore size of 3.72 nm. The chili stem activated carbon can reduce color by approximately 15% within 24 h and the maximum color reduction was 95% after 96 h for both activated carbon to biodiesel ratios. The color of biodiesel changes from dark red to yellow and eventually resulted in a pale yellow color with longer adsorption times and was deemed more attractive for use. Moreover, commercial activated carbon with its small pore size could not reduce the color, with a maximum reduction of only 3%.

Abstract. Proton therapy is one of the most accurate forms of cancer therapies, which requires accurate knowledge of the dose delivered to the patient and verification of the correct patient position with respect to the proton beam to avoid damage to critical normal tissues and geographical tumor misses. In existing proton treatment centers, dose calculation is performed based on X-ray computed tomography (CT), and the patient is positioned with x-ray radiographs. The use of X-ray CT images for proton treatment planning ignores fundamental differences in physical interaction processes between photons and protons and is therefore inherently inaccurate. Further, X-ray radiographs depict only skeletal structures; they do not show the tumor itself. Ideally, the image of the patient taken directly with proton CT by measuring the energy loss of high-energy protons that traverse the patient. The main content of this report is the application of simulation program PENH proton transmission via phantom associated with the PENEASY creation in proton imaging that can be applied in proton therapy.

Abstract. In dentistry, near-infrared (NIR) technology has been studied for decades that is being applied for the detection of dental damages without using ionizing radiation. Based on the interaction between dental tissue and NIR light such as transmission, absorption, and scattering, the teeth structure, and dental lesions can be observed by NIR images. The aim of this study was to build the dental diagnostic device using NIR light at 850-nm wavelength for detecting the early and hidden dental damages, that are not observed by X-rays. According to the various types of teeth samples, the transillumination and the scattering methods were designed and applied for capturing the teeth structures. The transillumination technique was used for thin teeth such as incisor and canine while the scattering system for observing the occlusal surface. The results show that the areas suspected to be the demineralized enamel are distinctly distinguished from the surrounding sound tissues and especially, the stain and pigmentation don’t appear in the NIR image. The designed device meets some requirements such as simple setup, safety, and affordable price for the purpose of replacement of imported equipment.

Abstract. In this research, we intend to present a novel mathematical approach to logistics which allows (financial) value to be associated with information as a central corporate resource. The inherent logistics processes (transport, production, sales) uncertainty requires continuous inventory monitoring and maintenance of safety stock levels. Literature and practice show that logistics responds to poor quality or incomplete information by increasing inventory.
In our research, we are looking for a minimum of safety stock levels based on the processing of information available in space and time and I intend to give a formal description of the mathematical model and present an example of its application.

Abstract. In recent years, oral problems are receiving more attention from not only experts but also almost people. If tooth lesions in the early stages, such as white spots, hidden dental caries, and tooth decay, etc., are not detected and treated promptly, they will lead to a risk of tooth loss. There are several common methods to detect tooth lesions such as clinical method, X-rays, and particularly near-infrared method, which is being developed significantly during the past decades. This method is substantially efficient for detecting early lesions by observing infrared images of tooth structures. In this study, near-infrared (NIR) light at 850 nm was used for detecting dental lesions. Enamel is nearly translucent in NIR light, so the lesions located under the enamel layer can be observed due to the interaction between NIR light and demineralized lesions. In addition, the NIR method is not only a safe method but also able to detect dental lesions at the early stage and tooth cracks which X-rays are limited to detect. In dentistry, an accurate diagnosis requires a combination of methods. Nowadays, X-rays are not only the common method but also the gold standard in dentistry, so this study incorporated clinical evaluation and X-rays to make the criteria for dental lesion diagnosis. This article has aimed to analyze and evaluate the effectiveness of the NIR imaging systems in detecting dental lesions and compare the NIR method to the clinical method combined with X-rays by Cohen's Kappa coefficient using SPSS (Statistical Package for the Social Sciences).

Abstract. In Vietnam, the operating room (OR) is used with max productivity. So, how to maintain comfort environment level, which is one of the assignments in designing and installing the operating room. In this study, the OR model is designed based on ASHRAE 170 – 2013 standard [1], and dimensions are referred to as “Comparison of Operating Room Ventilation System in the Protection of the Surgical Site” [2]. ANSYS CFX is used for calculating and simulating velocity and temperature of surveyed air points inside the room by many cases. A face temperature between 20,3 and 20,6 °C and a velocity of around 0,15 to 0,18 m/s is provided from the same laminar diffuser array. From the results, the OR comfort level is reviewed through the ADPI index.

Abstract. Cancer can be regarded as a rising threat to modern societies. Detecting cancer at an early stage significantly improves the durability of the disease; unfortunately, currently available methods for early diagnosis of cancer are scarce and inefficient. In fact, the concentration of Volatile Organic Compounds (VOCs) in cancer patients in the breath is different from that in normal people. Therefore, the development of new sensors that can detect VOCs with low concentrations at the early stage of cancer, is desirable. 2D materials are expected as attractive materials for these sensors due to their large surface area to volume ratio. In this work, we investigated the adsorption mechanism of some small-to-medium VOCs on the surface of silicene by the quantum simulation method. The images of the potential energy surfaces for different positions of the adsorbate on the silicene surface were explored by Computational DFT-based Nanoscope for the determination of the most stable configurations and diffusion possibilities. The adsorption energy profiles were calculated by three approximations of van der Waals interaction: revPBE-vdW, optPBE-vdW, and vdW-DF2. It is found that the adsorption energies of the VOCs in question vary in the range of 0.6-1.0 eV, which indicates that silicene is considerably sensitive with these VOCs. The charge transfer between the substrate and VOCs was also addressed.

Abstract. Segmentation is a grand challenge, and there are many contests are held around the world to solve this challenge, especially in the biomedical image. There are many solutions to solve this challenge have been published.
Nowadays, neural networks, including deep learning is a powerful and state-of-the-art way to segment objects from the background. But to use deep learning effectively, besides design a good network architecture, the preparation of input data is also an important requirement. Active contour (another name: Snake) is a classical segmentation technique in image processing. But the accuracy of this technique is not as high as we need for health care problems, and soft techniques such as neural networks or deep learning can improve this problem. But in those researches, deep learning is supplied to change the parameters of the active contour algorithm.
We propose a combination of two fields of solving segmentation problem, a classical one, and a modern: using data from active contour to be the input of deep learning. The images to be used in this research are human liver CT images.

Abstract. In this paper, the adiabatic theory is implemented to consider the ionization process of molecular system exposed to circularly polarized laser pulse. The photoelectron momentum distribution exhibits strong evidence of the properties of the molecular orbital. We also present the possibility to retrieve the ionization rate of the ionized electron from photoelectron momentum distribution in the transverse plane respecting to the polarized plane of the laser field. These results are vital in the viewpoint of the experiment. Several states of molecular hydrogen ion are considered for illustration.

Abstract. This study examines the: Sleep plays an important role in adjusting the balance of a stressful day since it helps to eliminate toxins and regenerating body energy. However, stressful life leads to sleeping disorders in many people. Lacking sleep causes dangerous health conditions such as cognitive decline, depression, and the most important one is a myocardial infarction. This study aimed at analyzing the sleep of healthy and insomnia subjects based on the characteristics and properties of brain signals. The power spectrum of the Alpha wave and the Delta wave was calculated and demonstrated on the graph for analyzing purposes. Based on the correlation between Alpha and Delta dual wave power spectrum, the condition of subjects was determined. Particularly, for insomnia subjects, the power spectral of Alpha and Delta correlated positively and vice versa. This research had successfully built a user interface for sleep detection using Brain mapping to visualize the power spectrum.

Abstract. Exercising is said to bring benefits to people taking part in, not only physical but also physiological gain. Heart Rate Variability (HRV) is an important marker reflecting the function of the autonomic nervous system (ANS), which has shown potentials in some exercise therapy and sport physiology studies. HRV analysis is said to be used for getting a better understanding of our body’s response to exercise and the reaction to different stressors from the workout. Thus, it is essential to monitor and optimize the recovery to avoid overtraining. This study aims to investigate the influence of HRV reflecting the physical stress level on participants when exercising, therefore, building a concept of self-training guide to improve the adaptation and performance. Electrocardiogram (ECG) is acquired by the BIOPAC system over 10 healthy college students during a proposed training protocol on the stationary bike, and post-exercising. HRV data from ECG is analyzed in time, frequency and nonlinear domains to extract various features to evaluate physiological recovery status, manage physical fatigue, intensity adjustment. From the evaluation of these indexes, participants are able to keep track of their physiological condition as well as to have more effective training exercises.

Abstract. Nowadays, fiber optical is used in many areas such as information transmission, medical with the advantage is rapid and avoid the loss of transmission efficiency. In medical use, the laser is increasingly used in rehabilitation treatment, especially low-level laser with the biological responses. Optic needle is one of the optimum options for bringing low-level lasers into the body through the intravenous route to interact with blood cells in blood vessels. We propose the application of fiber, the first step is the single-mode fiber in the low-level semiconductor red laser beam with wavelength 632,8 ~ 680nm into the vascular veins to provide effective low-level laser treatment. This paper reported the research on the production of intravenous optical needle.

Abstract. The structural changes of amorphous silicon (a-Si) under compressive pressure were examined by molecular-dynamics simulations using the Tersoff interatomic potential. a-Si prepared by melt-quenching methods was pressurized up to 30 GPa under different temperatures (300K and 500K). The density of a-Si increased from 2.26 to 3.24 g/cm3 with pressure, suggesting the occurrence of the low-density to high-density amorphous phase transformation. This phase transformation occurred at the lower pressure with increasing the temperature because the activation barrier for amorphous-to-amorphous phase transformation could be exceeded by thermal energy. The coordination number increased with pressure and time, and it was saturated at different values depending on the pressure. This suggested the existence of different metastable atomic configurations in a-Si. Atomic pair-distribution functions and bond-angle distribution functions suggested that the short-range ordered structure of high-density a-Si is similar to the structure of the high-pressure phase of crystalline Si (β-tin and Imma structures).

Abstract. This paper develops a numerical method that is capable of analyzing the aerodynamic characteristic of the helicopter main rotor in consider the influence of fuselage. The method is based on an unsteady nonlinear vortex-lattice method that can be used to simulate the interactions among the helicopter components efficiently. To clarify the effect of the main rotor-fuselage interaction, the aerodynamic characteristics of the main rotor in consider the influence of fuselage is determined along with those of the combined main rotor-fuselage system. The paper also shows the velocity field and free wake model in several flight regimes. The fuselage is modeled as a streamlined object, which is discretized into the system of quadrilateral vortex panels. The no-penetration boundary condition is satisfied on the fuselage surface, and no vorticity is shed from the fuselage. The results obtained in this paper are validated against experimental data and some from previous numerical methods.

Abstract. Near-infrared transillumination imaging is useful in many biomedical applications such as human biometrics and animal experiments. Using near-infrared (NIR) light, we can able to obtain a two dimensional (2D) transillumination image of the internal absorption structure such as blood vessel structure, liver ... in a small animal body. If we can obtain projection images from many orientations, we can reconstruct a three dimensional (3D) image using various computed tomography techniques. In previous studies of our group, even with a simple system (light-emitting diode (LED)'s array and low-cost camera), we can obtain the blood vessel transillumination image of the human arm. In this paper, we propose preliminary research on the development of a computed tomography (CT) scanner prototype of human body parts using transillumination imaging.

Abstract. An interpolation technique-based meshfree method using polynomial functions is employed to analyze the static behavior of sandwich beams with functionally graded face sheets and homogenous softcore. Various beam theories are expressed in general form and taken into account both shear deformation and normal deformation effects. The governing equation is derived from the principle of virtual work. The obtained results have been verified with the previously published works and a good agreement is found. The effects of skin-core-skin thickness ratios, material volume fraction indices, slenderness ratios, shear deformation, and thickness stretching effect on deflection and axial stress are investigated and discussed.

Abstract. Replacing von-Neumann architecture with walled carbon nanotube (SWNT) with new neuromorphic chips is vital for computers to perform polyoxometalate POM) ion ([SV2W10O40 ]H4TPP) complex cognitive problem with low power and see the effect of higher POM concentration. We consume like our brain. The synaptic part of the use simple sonication method for SWNT/POM brain has been well studied via memristors but fabrication and study the spiking and spike time research on the artificial neurons is only limited to high interval behavior via electrical measurements. The power CMOS circuitry. Following the previous work, results show that the device can behave as an artificial by H. Tanaka et al.[2] herein we functionalize single neuron even at low voltages and hence can be used for low power neuromorphic computing.

Abstract. The early diagnosis benefits the greater efficiency of the curing of breast cancer. One of the modalities for the detection of abnormal tissue in the present day is electrical impedance myography (EIM). EIM is a noninvasive electrophysiological technique, using a high frequency, low-intensity electrical current to derive voltage at the positions of sense electrodes. A Comsol Multiphysics-based finite element model was carried out in order to build the 3D model of breast tissue for computational simulation of the mentioned technique. EIM parameters of breast tissue involving resistance, reactance, phase angle in case of malignant tissue were calculated and compared with parameters of normal tissue. The results of the study showed some remarkable effects of tumor sizes, tumor positions, and electrode positions on the EIM parameters, which can be considered for potential early detection.

Abstract. This paper explores the optimal flight condition of an insect-like flapping-wing micro air vehicle (FWMAV) while ascending vertically at constant speeds. The FWMAV is assumed to have the same mass properties and wing geometry as those of the hawkmoth Manduca sexta. The optimization is conducted through the combination of an artificial neural network and a genetic algorithm. The training data for the artificial neural network are provided by the unsteady vortex-lattice method written in the programming language FORTRAN using parallel computation techniques. The results show that the FWMAV has to alter its wing kinematics and flapping frequency to sustain vertically ascending flight. Moreover, while ascending, the FWMAV requires more energy than that in hover. The findings from this work are useful for the design of control strategies used for insect-like FWMAVs

Abstract. This study addresses the development of a robot for inspection of old bridges. By suspending the robot with a wire and controlling the wire length, the movement of the robot is realized. The robot mounts a high-definition camera and aims to detect cracks on the concrete surface of the bridge using this camera. An inspection method using an unmanned aerial vehicle (UAV) has been proposed. Compared to the method using an unmanned aerial vehicle, the wire suspended robot system has the advantage of insensitivity to wind and ability to carry heavy equipments, this makes it possible to install a high-definition camera and a cleaning function to find cracks that are difficult to detect due to dirt.

Abstract. We are developing an autonomous field robot to save labor in forest operation. About half of Japan's artificial forest area is already available as wood. However, trees are not harvested and forest resources are not effectively used, because the labor and costs are not sufficient. The employment rate of young people in forestry tends to decline, and the unmanaged forest area is expected to increase in the future. Therefore, in our laboratory we propose an autonomous field robot with all terrain vehicles (ATV) that focuses on the automation of work. The robot we are developing automates weeding and observation for all trees in the forest. In this research, we introduced Robot Operating System (ROS) developed in recent years to this robot. In addition, we observed trees by generating an environmental map in the forest using Simultaneous Localization and Mapping (SLAM).

Abstract. This paper addresses the problem of using a mobile, autonomous robot to manage a forest whose trees are destined for eventual harvesting. We have been focussing a eliminate weeding operation because it is one of the hard work in the forestry works. This research proposing the computation of trajectory capable of traversing in the entire forest. The method is based on a graph whose vertices are trees located in the forest. Trees located in the forest will be treated as vertices in a graph. In the first, the initial graph is made with considering the safety of the robot. Next, editing the initial graph to be Eulerian, and finally, the Hamiltonian circuit is obtained which could be used for trajectory. By our proposed method, the trajectory of which feasible route for traversing of the entire forest would be obtained. In the experiment, we show the result of the method applying to actual artificial forest.

Abstract. The microstructural characteristics of liquid lithium silicate (Li2SiO3) are investigated by means of molecular dynamics simulation using the Born-Mayer pairwise potentials. The simulations were performed on the systems with up to 2025 atoms (consist of 750 Li, 375 Si, and 1125 O atoms) at 3200K in the 0-30 GPa pressure range. The microstructure of liquid Li2SiO3 is analyzed via pair radial distribution functions (PRDFs), coordination distributions, angular distributions. The results show that the structure of the liquid lithium silicate consists the basic structural units TO4 (T= Li, Si) at ambient pressure, and these units decrease as the pressure increases. Besides, the shape and size of the basic structural units are slightly dependent on pressure. Calculations also indicate that calculated data agree well with the experimental ones.

Abstract. We used the tube model with Go-like potential for native contacts to study the folding transition of a designed three-helix bundle and a designed protein G-like structure. It is shown that both proteins in this model are two-state folders with a cooperative folding transition coincided with the collapse transition. We defined the transition states as protein conformations in a small region around the saddle point on a free energy surface with the energy and the conformational root-mean-square deviation (RMSD) from the native state as the coordinates. The transition state region on the free energy surface then was sampled by using the umbrella sampling technique. We show that the transition state ensemble is broad consisting of different conformations that have different folded and unfolded elements.

Abstract. It is well-known that the laser-induced electron diffraction (LIED) contains molecular structural information that can be extracted with a spatial resolution of angström and time resolution of a few femtoseconds [1, 2]. The retrieval is based on the quantitative rescattering method (QRS) allowing the LIED signal to be split into two components [3], one of which is a laser-free differential cross-section (DCS) containing molecular structure. The method based on fitting the experimental DCS extracted from the LIED spectra to the theoretical DCS calculated with assumed initial structure parameters then allows one to reveal the real molecular structures. The theoretical DCS of molecules is treated within the independent atoms model (IAM) [1, 4] or the more advanced model based on the multiple scattering theory (MS) [2, 5].
In this report, we talk about how to consider the molecular vibration effect to the MS model and examine this effect of molecular vibrations on the DCS by comparing the oscillation component with the component of the MS second-order describing the interference of the scattering waves. We perform an application of the developed theory for some diatomic molecules.

Abstract. Glaucoma is the leading cause of irreversible blindness worldwide. Developed recently, OCTA is a promising non-invasive eye imaging tool for glaucoma diagnosis in the early stage. This research designed a diagnosis support software based on analyzing color-density map and ROIs vessel density index on the OCTA images scanned peripapillary and macula area. Hessian-based filter and Otsu thresholding were used to detect and enhance small vessels. The program greatly detected areas of vascular dropout on glaucoma eyes.

Abstract. Hyperelastic materials are special types of material that tends to behavior elastically when they are subjected to very large strains. These materials show not only the nonlinear material behavior but also the large deformation and stress-strain relationship is derived from a strain energy density function. Hyperelastic materials are widely used in many applications such as biological tissues, polymeric foams, and moreover. Neo - Hookean is a material model for hyperelastic solid which contains only two material parameters: bulk modulus and shear modulus. In the field of numerical analysis, the radial point interpolation method (RPIM) is a well-known meshfree method based on Garlekin's weak form. With the property of “free of mesh”, the RPIM approach shows its advantage for large deformation problems. In this study, a meshless radial point interpolation method is applied to demonstrate the elastic response of rubber-like materials based on the Mooney- Rivlin model. The obtained results are compared with the reference solutions given by other methods to verify the accuracy of the proposed method.

Abstract. In Vietnam, the number of people with limb defects or diseases that affect the ability of limbs is increasing [1]. They were reduced or incapable of living, unable to walk, to run, and utilities around them became useless. Therefore, it is imperative to build a patient support system in controlling external devices. Recognizing the problem, the author has studied, researched, and built a wheelchair control system based on speech recognition and eye movement. In this study, the eye movement system is at the simple level: glance left and right. The system uses an image processing method to locate the pupil. The external device for testing is a car model that control by Arduino connected via Bluetooth. Experimental evaluation results show that the eye movement system achieves high accuracy of over 70%. However, the eye movement system by image processing takes a lot of time to process for a command. All of the above shows the feasibility of developing an external control device for people with disabilities.

Abstract. In this paper, we investigate the linear perturbation of the material density of the universe in f(R) modified gravity of polynomial exponential form on the scale of distance below the cosmic horizon (sub-horizon). The results show that the model for the evolutionary aspects of the universe is slightly different from that in the standard cosmological model of ΛCDM. They can be used to show the difference between this modified gravitational model with the standard cosmological model of ΛCMD and other cosmological models. We also investigate the ration Ψ/ Φ and Geff / GN in the model and show that they are within allowable limits of experiments.

Abstract. The interaction between the Au8 cluster with cysteine (Cys) and glutathione (GSH) is investigated by means of density functional theory (DFT) using the PBE functional in conjunction with the cc-pVTZ basis set for non-metal atoms and the cc-pVTZ-PP basis set for gold. Harmonic vibrational frequencies are also calculated to confirm optimized geometries as local minima or transition states on the potential energy surfaces. The computed results show that these molecules prefer to anchor on the gold cluster via the sulfur atom with the adsorption energies of 20.3 and 30.8 kcal/mol for CYS and GSH, respectively, in the gas phase. In water, such values are considerably reduced, namely 19.0 kcal/mol for CYS and 26.4 kcal/mol for GSH. If a visible light with a frequency of v = 6x1014 Hz (500 nm) is applied, the time for the recovery of CYS and GSH from the most stable complexes will be about 1.24 and 6.03x107 seconds at 298 K in the gas phase. Such values significantly reduce to 0.14 and 4.08x104 in water. Thus, the Au8 cluster could be a promising material for designing tiny sensors in CYS and GSH selective detection.

Abstract. The work presents a simulation analysis of the bioimpedance at the human upper arm using the finite element method (FEM). Comsol Multiphysics has been used to create the 3D model with four domains of dielectric behavior: skin, fat, muscle, and bone. The main objective of this paper is to study the effect of the fat thickness and frequency on three parameters: resistance, reactance, and phase. The impedance values were calculated as the ratio of the output voltage at the electrodes and the applied current (1 mA). The measurements were done at four different values of the fat layer (10mm, 15mm, 20mm, and 25mm) and the electrical properties of the upper arm were used. The results clarify that the fat layer has a significant impact on the upper arm impedance across the frequency spectrum, resistance, and phase appear to be more affected than reactance.

Abstract. Cardiovascular diseases are the first cause of death globally: more people die annually from these diseases than from any other causes. These diseases are a group of disorders of the heart and blood vessels that appears silently but lead to many serious consequences for life. Vascular diseases including atherosclerosis, aneurysm, peripheral artery disease... affect the arteries, veins, or capillaries throughout the body and around the heart. Therefore, assessment of the quality of blood vessels early is extremely necessary in order to prevent cardiovascular diseases. Bioimpedance analysis is a non-invasive, safe, and low-cost technique that is widely used for diagnosing various diseases. This study conducts a novel method to evaluate the status of the blood vessels in two cases: stenosis and aneurysm based on bioimpedance signals. A 3D model of the forearm with several layers (skin, fat, muscle, bone, and blood vessel) and electrodes is simulated by using Comsol Multiphysics software. The electric impedance in different vascular conditions is examined. The results show that vessel impedance changed substantially because of vascular disorders. The bioimpedance signals vary according to the sizes of plaque and aneurysm wall. Consequently, bioimpedance analysis is reliable to detect vascular diseases and able to be applied in the near future.

Abstract. This experimental study aimed to evaluate if the effect simultaneously wavelengths of 780 nm and 940 nm enhances bone regeneration of the broken bone. Experiments on pets: 14 dogs, were randomly divided into 2 groups: group I (low-level laser therapy) and group II (control). The results showed that dogs in group I had better bone regeneration and bone marrow formation than the control group. Then, we treated 25 patients with different fracture levels. They agreed to enjoy our method. After treatment, the fracture is no longer visible on X-ray film. The majority of patients after treatment only feel no pain or mild pain. This suggests that osteoblasts are positively affected when projected by low-level laser. It is very practical for the treatment of older patients because osteoblasts grow slowly than osteoclast.

Abstract. Data loss prevention (DLP) is a set of tools and processes used to ensure that sensitive data is not lost, misused, or accessed by unauthorized users. The software and tools of DLP monitor and control endpoint activities, filter data streams on corporate networks, and monitor data in the cloud to protect data at rest, in motion, and in use. And in this study, we have designed the concept and draft scenarios of DLP for DataLake based on Abyss distributed storage cluster.

Abstract. Exercising is said to bring benefits to people taking part in, not only physical but also physiological gain. Heart Rate Variability (HRV) is an important marker reflecting the function of the autonomic nervous system (ANS), which has shown potentials in some exercise therapy and sport physiology studies. HRV analysis is said to be used for getting a better understanding of our body’s response to exercise and the reaction to different stressors from the workout. Thus, it is essential to monitor and optimize the recovery to avoid overtraining. This study aims to investigate the influence of HRV reflecting the physical stress level on participants when exercising, therefore, building a concept of self-training guide to improve the adaptation and performance. Electrocardiogram (ECG) is acquired by the BIOPAC system over 10 healthy college students during a proposed training protocol on the stationary bike, and post-exercising. HRV data from ECG is analyzed in time, frequency and nonlinear domains to extract various features to evaluate physiological recovery status, manage physical fatigue, intensity adjustment. From the evaluation of these indexes, participants are able to keep track of their physiological condition as well as to have more effective training exercises.

Abstract. Differential Evolution and Dynamic Programming are used in reservoir regulation in much research. In the previous works, we presented the outline of Differential Evolution and Dynamic Programming and separately applied them into the Pleikrong reservoir and Italy reservoir, two biggest ones in the Highland of Vietnam for the dry season of 2010 and 2012. Continuing from that, in this work, we apply these methods to these two reservoirs at the same time as a multi-reservoir system to reach optimal regulation for the maximum power production.