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Appl. Sci., Volume 8, Issue 7 (July 2018)

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Open AccessArticle Low-Velocity Impacts on a Polymeric Foam for the Passive Safety Improvement of Sports Fields: Meshless Approach and Experimental Validation
Appl. Sci. 2018, 8(7), 1174; https://doi.org/10.3390/app8071174 (registering DOI)
Received: 31 January 2018 / Revised: 29 June 2018 / Accepted: 12 July 2018 / Published: 18 July 2018
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Abstract
Over the past few years, foam materials have been increasingly used in the passive safety of sport fields, to mitigate the risk of crash injury. Currently, the passive safety certification process of these materials represents an expensive and time-consuming task, since a considerable
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Over the past few years, foam materials have been increasingly used in the passive safety of sport fields, to mitigate the risk of crash injury. Currently, the passive safety certification process of these materials represents an expensive and time-consuming task, since a considerable number of impact tests on material samples have to be carried out by an ad hoc testing apparatus. To overcome this difficulty and speed up the design process of new protective devices, a virtual model for the low-velocity impact behaviour of foam protective mats is needed. In this study a modelling approach based on the mesh-free Element Galerkin method was developed to investigate the impact behaviour of ethylene-vinyl acetate (EVA) foam protective mats. The main advantage of this novel technique is that the difficulties related to the computational mesh distortion and caused by the large deformation of the foam material are avoided and a good accuracy is achieved at a relatively low computational cost. The numerical model was validated statistically by comparing numerical and experimental acceleration data acquired during a series of impact events on EVA foam mats of various thicknesses. The findings of this study are useful for the design and improvement of foam protective devices and allow for optimizing sports fields’ facilities by reducing head injury risk by a reliable computational method. Full article
(This article belongs to the Special Issue Sports Materials)
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Open AccessArticle Incorporating Grey Total Influence into Tolerance Rough Sets for Classification Problems
Appl. Sci. 2018, 8(7), 1173; https://doi.org/10.3390/app8071173 (registering DOI)
Received: 7 June 2018 / Revised: 12 July 2018 / Accepted: 13 July 2018 / Published: 18 July 2018
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Abstract
Tolerance-rough-set-based classifiers (TRSCs) are known to operate effectively on real-valued attributes for classification problems. This involves creating a tolerance relation that is defined by a distance function to estimate proximity between any pair of patterns. To improve the classification performance of the TRSC,
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Tolerance-rough-set-based classifiers (TRSCs) are known to operate effectively on real-valued attributes for classification problems. This involves creating a tolerance relation that is defined by a distance function to estimate proximity between any pair of patterns. To improve the classification performance of the TRSC, distance may not be an appropriate means of estimating similarity. As certain relations hold among the patterns, it is interesting to consider similarity from the perspective of these relations. Thus, this study uses grey relational analysis to identify direct influences by generating a total influence matrix to verify the interdependence among patterns. In particular, to maintain the balance between a direct and a total influence matrix, an aggregated influence matrix is proposed to form the basis for the proposed grey-total-influence-based tolerance rough set (GTI-TRS) for pattern classification. A real-valued genetic algorithm is designed to generate the grey tolerance class of a pattern to yield high classification accuracy. The results of experiments showed that the classification accuracy obtained by the proposed method was comparable to those obtained by other rough-set-based methods. Full article
(This article belongs to the Section Computer Science and Electrical Engineering)
Open AccessArticle Refractive Index Sensing through Surface Plasmon Resonance in Light-Diffusing Fibers
Appl. Sci. 2018, 8(7), 1172; https://doi.org/10.3390/app8071172 (registering DOI)
Received: 28 June 2018 / Revised: 16 July 2018 / Accepted: 16 July 2018 / Published: 18 July 2018
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Abstract
In this paper, we show that light-diffusing fibers (LDF) can be efficiently used as host material for surface plasmon resonance (SPR)-based refractive index sensing. This novel platform does not require a chemical procedure to remove the cladding or enhance the evanescent field, which
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In this paper, we show that light-diffusing fibers (LDF) can be efficiently used as host material for surface plasmon resonance (SPR)-based refractive index sensing. This novel platform does not require a chemical procedure to remove the cladding or enhance the evanescent field, which is expected to give better reproducibility of the sensing interface. The SPR sensor has been realized by first removing the cladding with a simple mechanical stripper, and then covering the unclad fiber surface with a thin gold film. The tests have been carried out using water–glycerin mixtures with refractive indices ranging from 1.332 to 1.394. The experimental results reveal a high sensitivity of the SPR wavelength to the outer medium’s refractive index, with values ranging from ~1500 to ~4000 nm/RIU in the analyzed range. The results suggest that the proposed optical fiber sensor platform could be used in biochemical applications. Full article
(This article belongs to the Special Issue Photonic Metamaterials)
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Open AccessArticle Strain Transfer Characteristic of a Fiber Bragg Grating Sensor Bonded to the Surface of Carbon Fiber Reinforced Polymer Laminates
Appl. Sci. 2018, 8(7), 1171; https://doi.org/10.3390/app8071171 (registering DOI)
Received: 13 June 2018 / Revised: 13 July 2018 / Accepted: 16 July 2018 / Published: 18 July 2018
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Abstract
Structural health monitoring is of great importance for the application of composites in aircrafts. Fiber Bragg grating (FBG) sensors are very suitable for structure strain measurement. However, the strain measured by FBG sensors is different from the original strain in host materials. The
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Structural health monitoring is of great importance for the application of composites in aircrafts. Fiber Bragg grating (FBG) sensors are very suitable for structure strain measurement. However, the strain measured by FBG sensors is different from the original strain in host materials. The relationship between them is defined as strain transfer. As composites are anisotropic, the traditional strain transfer model, which regards the elasticity modulus of host materials as a constant, is inadaptable. In this paper, a new strain transfer model is proposed for FBG sensors bonded to the surface of carbon fiber reinforced polymer (CFRP) laminates. Based on the measurement structure, the model is established and the transfer function is derived. The characteristics influencing the strain transfer are analyzed. The stacking directions, stacking numbers, and stacking sequences of CFRP laminates have a distinct effect on the transfer efficiency, which is different from the isotropy host materials. The accuracy of the proposed model was verified by experiments on a nondestructive tensile system, and the maximum model error is less than 0.5%. Moreover, the model was applied to the strain measurement of CFRP wing skin, which indicates that measurement errors decrease by 11.6% to 19.8% after the compensation according to the model. Full article
(This article belongs to the Special Issue Fiber Bragg Gratings: Fundamentals, Materials and Applications)
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Open AccessFeature PaperArticle Shear Wave Elastography Measures of the Achilles Tendon: Influence of Time of Day, Leg Dominance and the Impact of an Acute 30-Minute Bout of Running
Appl. Sci. 2018, 8(7), 1170; https://doi.org/10.3390/app8071170 (registering DOI)
Received: 27 June 2018 / Revised: 13 July 2018 / Accepted: 16 July 2018 / Published: 18 July 2018
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Abstract
The mechanical properties of human tendons are likely to be influenced by factors known to affect elastic structures, including patterns of loading and unloading during the day. However, the exact scale and relevance of these variables to tendon stiffness remains unclear. The aim
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The mechanical properties of human tendons are likely to be influenced by factors known to affect elastic structures, including patterns of loading and unloading during the day. However, the exact scale and relevance of these variables to tendon stiffness remains unclear. The aim of this study was to (1) measure Achilles tendon (AT) stiffness over the course of the day, (2) examine AT stiffness between dominant and non-dominant standing leg tendons and (3) assess the impact of previous activity on AT stiffness. To assess the impact of time of day and leg dominance, 15 healthy participants (6 females, 9 males; mean age 28 ± 4 year, mean VISA-A score 99.0 ± 1.2) had shear wave elastography (SWE) measures taken at 08:00 h, 12:30 h and 17:00 h on both dominant and non-dominant legs. To assess the impact of exercise, 24 tendons were analysed (7 females, 5 males; mean age 27 ± 4 year, mean VISA-A Score 99.1 ± 1.1) with participants randomly assigned to either a control (CONT) group or a running (RUN) group. The RUN group performed a 30-min run at a subjective intensity of 13–15 on rating of perceived exertion (RPE) scale and had SWE measures taken before, immediately after, 6 h 24 h, 48 h and 72 h following the run. There were no significant differences in AT stiffness over the course of a day or between dominant and non-dominant leg. Significant increases in AT stiffness were noted pre-post run (0.27 m/s, 2.95%, p = 0.037). Leg dominance does not affect SWE values from asymptomatic ATs or change throughout a day, but a 30-min run significantly increases AT stiffness. Leg dominance and timing of clinical appointments are unlikely to affect SWE results, however a prior bout of physical activity may cause changes within the AT resulting in a significantly different SWE measure. Clinicians and researchers should be cautious of interpreting SWE results if weight bearing exercise has been performed beforehand. Full article
(This article belongs to the Special Issue Ultrasound Elastography)
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Open AccessArticle Real-Time Swarm Search Method for Real-World Quadcopter Drones
Appl. Sci. 2018, 8(7), 1169; https://doi.org/10.3390/app8071169 (registering DOI)
Received: 9 June 2018 / Revised: 13 July 2018 / Accepted: 17 July 2018 / Published: 18 July 2018
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Abstract
This paper proposes a novel search method for a swarm of quadcopter drones. In the proposed method, inspired by the phenomena of swarms in nature, drones effectively look for the search target by investigating the evidence from the surroundings and communicating with each
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This paper proposes a novel search method for a swarm of quadcopter drones. In the proposed method, inspired by the phenomena of swarms in nature, drones effectively look for the search target by investigating the evidence from the surroundings and communicating with each other. The position update mechanism is implemented using the particle swarm optimization algorithm as the swarm intelligence (a well-known swarm-based optimization algorithm), as well as a dynamic model for the drones to take the real-world environment into account. In addition, the mechanism is processed in real-time along with the movements of the drones. The effectiveness of the proposed method was verified through repeated test simulations, including a benchmark function optimization and air pollutant search problems. The results show that the proposed method is highly practical, accurate, and robust. Full article
(This article belongs to the Special Issue Swarm Robotics)
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Open AccessArticle Acridine-Triphenylamine Based Hole-Transporting and Hole-Injecting Material for Highly Efficient Phosphorescent-Based Organic Light Emitting Diodes
Appl. Sci. 2018, 8(7), 1168; https://doi.org/10.3390/app8071168 (registering DOI)
Received: 25 June 2018 / Revised: 7 July 2018 / Accepted: 17 July 2018 / Published: 18 July 2018
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Abstract
In this study, triphenylamine-based hole-transporting material 4-(9,9-diphenylacridin-10(9H)-yl)-N-(4-(9,9-diphenylacridin-10(9H)-yl) phenyl)-N-phenylaniline (TPA-1A) was designed and synthesized by using single-step Buchwald–Hartwig coupling reaction with higher yield percentage of 76%. Our synthesized TPA-1A showed excellent thermal stability, with a higher
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In this study, triphenylamine-based hole-transporting material 4-(9,9-diphenylacridin-10(9H)-yl)-N-(4-(9,9-diphenylacridin-10(9H)-yl) phenyl)-N-phenylaniline (TPA-1A) was designed and synthesized by using single-step Buchwald–Hartwig coupling reaction with higher yield percentage of 76%. Our synthesized TPA-1A showed excellent thermal stability, with a higher glass transition temperature of 176 °C and decomposition temperature of 474 °C at 5% weight reduction. TPA-1A based green phosphorescent organic light emitting diodes (PhOLED) device was fabricated to investigate the device properties and compare it with the similar reference N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB)based device. The TPA-1A-based PhOLED demonstrated an excellent current and power efficiency of 49.13 cd/A and 27.56 lm/W, respectively. Moreover, TPA-1A demonstrated better hole injection efficiencies as well. The overall efficiencies were better than the reference NPB-based device. Full article
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Open AccessArticle Validation of a Wearable IMU System for Gait Analysis: Protocol and Application to a New System
Appl. Sci. 2018, 8(7), 1167; https://doi.org/10.3390/app8071167 (registering DOI)
Received: 8 June 2018 / Revised: 3 July 2018 / Accepted: 12 July 2018 / Published: 18 July 2018
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Abstract
Miniaturized wearable Inertial Measurement Units (IMU) offer new opportunities for the functional assessment of motor functions for medicine, sport, and ergonomics. Sparse reliability validation studies have been conducted without a common specific approach and protocol. A set of guidelines to design validation protocol
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Miniaturized wearable Inertial Measurement Units (IMU) offer new opportunities for the functional assessment of motor functions for medicine, sport, and ergonomics. Sparse reliability validation studies have been conducted without a common specific approach and protocol. A set of guidelines to design validation protocol for these systems is proposed hereafter. They are based on the comparison between video analysis and the gold standard optoelectronic motion capture system for Gait Analysis (GA). A setup of the protocol has been applied to a wearable device implementing an inertial measurement unit and a dedicated harmonic oscillator kinematic model of the center of mass. In total, 10 healthy volunteers took part in the study, and four trials of walking at a self-selected speed and step length have been simultaneously recorded by the two systems, analyzed, and compared blindly (40 datasets). The model detects the steps and the foot which supports body weight. The stride time and the cadence have a mean absolute percentage error of 5.7% and 4.9%, respectively. The mean absolute percentage error in the measurement of step’s length and step’s speed is 5.6% and 13.5%, respectively. Results confirm that the proposed methodology is complete and effective. It is demonstrated that the developed wearable system allows for a reliable assessment of human gait spatio-temporal parameters. Therefore, the goal of this paper is threefold. The first goal is to present and define structured Protocol Design Guidelines, where the related setup is implemented for the validation of wearable IMU systems particularly dedicated to GA and gait monitoring. The second goal is to apply these Protocol Design Guidelines to a case study in order to verify their feasibility, user-friendliness, and efficacy. The third goal is the validation of our biomechanical kinematic model with the gold standard reference. Full article
(This article belongs to the Special Issue Smart Fabrics Technologies and Applications)
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Open AccessArticle Modeling of Gas Permeation through Mixed-Matrix Membranes Using Novel Computer Application MOT
Appl. Sci. 2018, 8(7), 1166; https://doi.org/10.3390/app8071166 (registering DOI)
Received: 5 June 2018 / Revised: 11 July 2018 / Accepted: 16 July 2018 / Published: 18 July 2018
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Abstract
The following article proposes a modern computer application MOT (Membrane Optimization Tool) for modeling of gas transport processes through mixed-matrix membranes (MMMs). The current version of the application is based on the Maxwell model, which can be successfully used to model gas transport
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The following article proposes a modern computer application MOT (Membrane Optimization Tool) for modeling of gas transport processes through mixed-matrix membranes (MMMs). The current version of the application is based on the Maxwell model, which can be successfully used to model gas transport through the simplest types of hybrid membranes without any defects. The application has been verified on the example of four types of hybrid membranes, consisting of various types of polymer matrix, such as: poly (vinyl acetate), 2, 2′-BAPB + BPADA, Ultem, hyperbranched polyimide (ODPA-MTA) and zeolite 4A. The average absolute relative error (AARE) and root-mean-square error (RMSE) were calculated in order to compare the theoretical MOT-predicted results with the experimental results. It was found that the AARE ranges from 29% to 36%, while the RMSE is in the range of 10% to 29%. The article presents also the comparison of MOT-predicted data obtained with Maxwell and Bruggeman models. To obtain more accurate reproduction of experimental results, further versions of the proposed application will be extended with next-generation permeation models (Lewis–Nielsen, Pal, modified Maxwell or Felske models), allowing for the description of transport in more complex systems with the possibility of taking into account possible defects. Full article
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Open AccessArticle MCDM-ECP: Multi Criteria Decision Making Method for Emergency Communication Protocol in Disaster Area Wireless Network
Appl. Sci. 2018, 8(7), 1165; https://doi.org/10.3390/app8071165 (registering DOI)
Received: 22 June 2018 / Revised: 9 July 2018 / Accepted: 10 July 2018 / Published: 18 July 2018
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Abstract
Disaster Area Wireless Networks (DAWNs) are widely deployed in natural or man-made disaster scenes, since the communication infrastructure may be completely destroyed by the disaster. This paper proposes a hybrid network architecture for DAWNs due to the mobility of first responders and refugees.
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Disaster Area Wireless Networks (DAWNs) are widely deployed in natural or man-made disaster scenes, since the communication infrastructure may be completely destroyed by the disaster. This paper proposes a hybrid network architecture for DAWNs due to the mobility of first responders and refugees. Based on the link characterization of DAWNs, we choose four essential criteria and propose a multi-criteria decision-making method for emergency communication protocol (MCDM-ECP), which utilizes the analytic hierarchy process (AHP) method and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method to find the optimal next-hop node in DAWNs. Routing discovery and routing maintenance processes are included in the novel protocol. The simulation results show that MCDM-ECP performs better than other classical protocols both in energy consumption and packet received rate (PRR) for long-term emergency communications. Full article
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Open AccessArticle An Integrated Self-Diagnosis System for an Autonomous Vehicle Based on an IoT Gateway and Deep Learning
Appl. Sci. 2018, 8(7), 1164; https://doi.org/10.3390/app8071164 (registering DOI)
Received: 14 June 2018 / Revised: 9 July 2018 / Accepted: 13 July 2018 / Published: 18 July 2018
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Abstract
This paper proposes “An Integrated Self-diagnosis System (ISS) for an Autonomous Vehicle based on an Internet of Things (IoT) Gateway and Deep Learning” that collects information from the sensors of an autonomous vehicle, diagnoses itself, and the influence between its parts by using
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This paper proposes “An Integrated Self-diagnosis System (ISS) for an Autonomous Vehicle based on an Internet of Things (IoT) Gateway and Deep Learning” that collects information from the sensors of an autonomous vehicle, diagnoses itself, and the influence between its parts by using Deep Learning and informs the driver of the result. The ISS consists of three modules. The first In-Vehicle Gateway Module (In-VGM) collects the data from the in-vehicle sensors, consisting of media data like a black box, driving radar, and the control messages of the vehicle, and transfers each of the data collected through each Controller Area Network (CAN), FlexRay, and Media Oriented Systems Transport (MOST) protocols to the on-board diagnostics (OBD) or the actuators. The data collected from the in-vehicle sensors is transferred to the CAN or FlexRay protocol and the media data collected while driving is transferred to the MOST protocol. Various types of messages transferred are transformed into a destination protocol message type. The second Optimized Deep Learning Module (ODLM) creates the Training Dataset on the basis of the data collected from the in-vehicle sensors and reasons the risk of the vehicle parts and consumables and the risk of the other parts influenced by a defective part. It diagnoses the vehicle’s total condition risk. The third Data Processing Module (DPM) is based on Edge Computing and has an Edge Computing based Self-diagnosis Service (ECSS) to improve the self-diagnosis speed and reduce the system overhead, while a V2X based Accident Notification Service (VANS) informs the adjacent vehicles and infrastructures of the self-diagnosis result analyzed by the OBD. This paper improves upon the simultaneous message transmission efficiency through the In-VGM by 15.25% and diminishes the learning error rate of a Neural Network algorithm through the ODLM by about 5.5%. Therefore, in addition, by transferring the self-diagnosis information and by managing the time to replace the car parts of an autonomous driving vehicle safely, this reduces loss of life and overall cost. Full article
(This article belongs to the Special Issue Fault Detection and Diagnosis in Mechatronics Systems)
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Open AccessFeature PaperArticle Nanostructured Lipid Carriers as Promising Delivery Systems for Plant Extracts: The Case of Silymarin
Appl. Sci. 2018, 8(7), 1163; https://doi.org/10.3390/app8071163 (registering DOI)
Received: 29 June 2018 / Revised: 14 July 2018 / Accepted: 16 July 2018 / Published: 18 July 2018
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Abstract
Background: Silymarin is the extract from seeds of Silybum marianum L. Gaertn. and it has been used for decades as hepatoprotectant. Recently, it has been proposed to be beneficial in type 2 diabetes patients. However, silymarin is a poorly water soluble drug with
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Background: Silymarin is the extract from seeds of Silybum marianum L. Gaertn. and it has been used for decades as hepatoprotectant. Recently, it has been proposed to be beneficial in type 2 diabetes patients. However, silymarin is a poorly water soluble drug with limited oral bioavailability. In this study, nanostructured lipid carriers were proposed to enhance its solubility and intestinal absorption. Methods: Nanostructured lipid carriers were made of Stearic acid:Capryol 90 as lipid mixtures and Brij S20 as surfactant. Formulations were physically and chemically characterized. Stability and in vitro release studies were also assessed. In vitro permeability and Caco-2 cellular uptake mechanism were investigated. Results: Obtained results were based on size, homogeneity, ζ-potential and EE%. Nanostructured lipid carriers could be orally administered. No degradation phenomena were observed in simulated gastrointestinal fluids. Storage stability of suspensions and lyophilized products was also tested. Glucose was selected as best cryoprotectant agent. About 60% of silymarin was released in 24 h in phosphate buffered saline. In vitro parallel artificial membrane permeability assay experiments revealed that the nanocarrier enhanced the permeation of Silymarin. Caco-2 study performed with fluorescent nanoparticles revealed the ability of carrier to enhance the permeation of a lipophilic probe. Cellular uptake studies indicated that active process is involved in the internalization of the formulation. Conclusions: The optimized nanostructured lipid carriers showed excellent chemical and physical stability and enhanced the absorption of silymarin. Full article
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Open AccessFeature PaperArticle Smart System for the Optimization of Logistics Performance of the Pruning Biomass Value Chain
Appl. Sci. 2018, 8(7), 1162; https://doi.org/10.3390/app8071162 (registering DOI)
Received: 19 June 2018 / Revised: 10 July 2018 / Accepted: 10 July 2018 / Published: 18 July 2018
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Abstract
Agricultural pruning biomass is one of the important resources in Europe for generating renewable energy. However, utilization of the agricultural residues requires development of efficient and effective logistics systems. The objective of this study was to develop smart logistics system (SLS) appropriate for
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Agricultural pruning biomass is one of the important resources in Europe for generating renewable energy. However, utilization of the agricultural residues requires development of efficient and effective logistics systems. The objective of this study was to develop smart logistics system (SLS) appropriate for the management of the pruning biomass supply chain. The paper describes the users’ requirement of SLS, defines the technical and functional requirements and specifications for the development of SLS, and determines relevant information/data to be documented and managed by the SLS. This SLS has four major components: (a) Smart box, a sensor unit that enables measurement of data such as relative humidity, temperature, geographic positions; (b) On-board control unit, a unit that performs route planning and monitors the recordings by the smart box; (c) Information platform, a centralized platform for data storing and sharing, and management of pruning supply chain and traceability; and (d) Central control unit, an interface linking the Information platform and On-board control unit that serves as a point of administration for the whole pruning biomass supply chain from harvesting to end user. The SLS enables the improvement of performance of pruning biomass supply chain management and product traceability leading to a reduction of product loss, increased coordination of resources utilisation and quality of solid biofuel supply, increased pruning marketing opportunity, and reduction of logistics cost. This SLS was designed for pruning biomass, but could also be adapted for any type of biomass-to-energy initiatives. Full article
(This article belongs to the Special Issue Sustainable Energy Systems Planning, Integration and Management)
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Open AccessArticle An Upper Extremity Rehabilitation System Using Efficient Vision-Based Action Identification Techniques
Appl. Sci. 2018, 8(7), 1161; https://doi.org/10.3390/app8071161
Received: 30 May 2018 / Revised: 6 July 2018 / Accepted: 10 July 2018 / Published: 17 July 2018
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Abstract
This study proposes an action identification system for home upper extremity rehabilitation. In the proposed system, we apply an RGB-depth (color-depth) sensor to capture the image sequences of the patient’s upper extremity actions to identify its movements. We apply a skin color detection
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This study proposes an action identification system for home upper extremity rehabilitation. In the proposed system, we apply an RGB-depth (color-depth) sensor to capture the image sequences of the patient’s upper extremity actions to identify its movements. We apply a skin color detection technique to assist with extremity identification and to build up the upper extremity skeleton points. We use the dynamic time warping algorithm to determine the rehabilitation actions. The system presented herein builds up upper extremity skeleton points rapidly. Through the upper extremity of the human skeleton and human skin color information, the upper extremity skeleton points are effectively established by the proposed system, and the rehabilitation actions of patients are identified by a dynamic time warping algorithm. Thus, the proposed system can achieve a high recognition rate of 98% for the defined rehabilitation actions for the various muscles. Moreover, the computational speed of the proposed system can reach 125 frames per second—the processing time per frame is less than 8 ms on a personal computer platform. This computational efficiency allows efficient extensibility for future developments to deal with complex ambient environments and for implementation in embedded and pervasive systems. The major contributions of the study are: (1) the proposed system is not only a physical exercise game, but also a movement training program for specific muscle groups; (2) The hardware of upper extremity rehabilitation system included a personal computer with personal computer and a depth camera. These are economic equipment, so that patients who need this system can set up one set at home; (3) patients can perform rehabilitation actions in sitting position to prevent him/her from falling down during training; (4) the accuracy rate of identifying rehabilitation action is as high as 98%, which is sufficient for distinguishing between correct and wrong action when performing specific action trainings; (5) The proposed upper extremity rehabilitation system is real-time, efficient to vision-based action identification, and low-cost hardware and software, which is affordable for most families. Full article
(This article belongs to the Special Issue Selected Papers from the 2017 International Conference on Inventions)
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Open AccessArticle Hierarchical Mobile Edge Computing Architecture Based on Context Awareness
Appl. Sci. 2018, 8(7), 1160; https://doi.org/10.3390/app8071160
Received: 27 June 2018 / Revised: 7 July 2018 / Accepted: 12 July 2018 / Published: 17 July 2018
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Abstract
Due to the recent developments in mobile network technology and the supply of mobile devices, services that require high computing power and fast access speed, such as machine learning and multimedia streaming, are attracting attention. Mobile Edge Computing (MEC) has emerged. MEC allows
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Due to the recent developments in mobile network technology and the supply of mobile devices, services that require high computing power and fast access speed, such as machine learning and multimedia streaming, are attracting attention. Mobile Edge Computing (MEC) has emerged. MEC allows servers to be located close to users to efficiently handle these services and provides users with ultra-low latency content delivery and powerful computing services. However, there has been a lack of research into the architecture required to efficiently use the computing power and resources of MEC. So, this paper proposes hierarchical MEC architecture in which MEC servers (MECS) are arranged in a hierarchical scheme to provide users with rapid content delivery, high computing performance, and efficient use of server resources. Full article
(This article belongs to the Special Issue Mobile Cloud Computing)
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