Next Issue
Previous Issue

Table of Contents

Appl. Sci., Volume 7, Issue 9 (September 2017)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Cover Story (view full-size image) The presented image are surface morphology of aluminum 1050 alloy subjected to plasma electrolytic [...] Read more.
View options order results:
result details:
Displaying articles 1-98
Export citation of selected articles as:
Open AccessEditorial Editorial: Guided-Wave Optics
Appl. Sci. 2017, 7(9), 962; https://doi.org/10.3390/app7090962
Received: 11 September 2017 / Revised: 15 September 2017 / Accepted: 15 September 2017 / Published: 20 September 2017
PDF Full-text (262 KB) | HTML Full-text | XML Full-text
Abstract
Guided waves represent a vast class of phenomena in which the propagation of collective excitations in various media is steered in required directions by fixed (or, sometimes, reconfigurable) conduits [...]
Full article
(This article belongs to the Special Issue Guided-Wave Optics) Printed Edition available
Open AccessArticle Application of Artificial Neural Networks to Ship Detection from X-Band Kompsat-5 Imagery
Appl. Sci. 2017, 7(9), 961; https://doi.org/10.3390/app7090961
Received: 31 July 2017 / Revised: 10 September 2017 / Accepted: 18 September 2017 / Published: 20 September 2017
Cited by 2 | PDF Full-text (5024 KB) | HTML Full-text | XML Full-text
Abstract
For ship detection, X-band synthetic aperture radar (SAR) imagery provides very useful data, in that ship targets look much brighter than surrounding sea clutter due to the corner-reflection effect. However, there are many phenomena which bring out false detection in the SAR image,
[...] Read more.
For ship detection, X-band synthetic aperture radar (SAR) imagery provides very useful data, in that ship targets look much brighter than surrounding sea clutter due to the corner-reflection effect. However, there are many phenomena which bring out false detection in the SAR image, such as noise of background, ghost phenomena, side-lobe effects and so on. Therefore, when ship-detection algorithms are carried out, we should consider these effects and mitigate them to acquire a better result. In this paper, we propose an efficient method to detect ship targets from X-band Kompsat-5 SAR imagery using the artificial neural network (ANN). The method produces the ship-probability map using ANN, and then detects ships from the ship-probability map by using a threshold value. For the purpose of getting an improved ship detection, we strived to produce optimal input layers used for ANN. In order to reduce phenomena related to the false detections, the non-local (NL)-means filter and median filter were utilized. The NL-means filter effectively reduced noise on SAR imagery without smoothing edges of the objects, and the median filter was used to remove ship targets in SAR imagery. Through the filtering approaches, we generated two input layers from a Kompsat-5 SAR image, and created a ship-probability map via ANN from the two input layers. When the threshold value of 0.67 was imposed on the ship-probability map, the result of ship detection from the ship-probability map was a 93.9% recall, 98.7% precision and 6.1% false alarm rate. Therefore, the proposed method was successfully applied to the ship detection from the Kompsat-5 SAR image. Full article
Figures

Figure 1

Open AccessArticle Antimony Oxide-Doped 0.99Pb(Zr0.53Ti0.47)O3–0.01Bi(Y1−xSbx)O3 Piezoelectric Ceramics for Energy-Harvesting Applications
Appl. Sci. 2017, 7(9), 960; https://doi.org/10.3390/app7090960
Received: 10 August 2017 / Revised: 14 September 2017 / Accepted: 14 September 2017 / Published: 19 September 2017
PDF Full-text (3285 KB) | HTML Full-text | XML Full-text
Abstract
The effects of doping antimony oxides (Sb2O3/Sb2O5) on the ferroelectric/piezoelectric and energy-harvesting properties of 0.99Pb(Zr0.53Ti0.47)O3–0.01BiYO3 (PZT–BY) have been studied. The feasibility of doping Sb2O3 and
[...] Read more.
The effects of doping antimony oxides (Sb2O3/Sb2O5) on the ferroelectric/piezoelectric and energy-harvesting properties of 0.99Pb(Zr0.53Ti0.47)O3–0.01BiYO3 (PZT–BY) have been studied. The feasibility of doping Sb2O3 and Sb2O5 into the PZT–BY ceramics has also been compared by considering factors such as sintering condition, grain size, density, and electrical properties etc. This work discusses a detailed experimental observation using Sb2O3, because Sb2O5 is relatively expensive and does not follow the stoichiometric reaction mechanism when doped in PZT–BY. The Sb2O3-doped specimens were well sintered by oxygen-rich sintering and reached a maximum density of 99.1% of the theoretical value. X-ray diffraction (XRD) analysis showed a complete solid solution for all the specimens. Scanning electron microscope (SEM) observation revealed that the addition of Sb2O3 inhibits grain growth, and exhibits a denser and finer microstructure. The 0.1 moles of Sb2O3-doped ceramic shows a sharp decrease in the dielectric constant (ε33T = 690), while the piezoelectric charge constant (d33) and electromechanical coupling factor (kp) maintained high values of 350 pC/N and 66.0% respectively. The relatively higher value of d33 and lower ε33T of the 0.99Pb(Zr0.53Ti0.47)O3–0.01Bi(Y0.9Sb0.1)O3 ceramic resulted in an optimum value of piezoelectric voltage constant (g33 = 57.4 × 10−3 Vm/N) and a high figure of merit (d33 × g33 = 20075 × 10−15 m2/N). These values are high compared to recently reported works. Therefore, Sb2O3-doped PZT–BY ceramic could be a promising candidate material for the future study of power-harvesting devices. Full article
Figures

Graphical abstract

Open AccessTechnical Note Which Method Detects Foot Strike in Rearfoot and Forefoot Runners Accurately when Using an Inertial Measurement Unit?
Appl. Sci. 2017, 7(9), 959; https://doi.org/10.3390/app7090959
Received: 17 August 2017 / Revised: 11 September 2017 / Accepted: 15 September 2017 / Published: 19 September 2017
Cited by 2 | PDF Full-text (571 KB) | HTML Full-text | XML Full-text
Abstract
Accelerometers and gyroscopes are used to detect foot strike (FS), i.e., the moment when the foot first touches the ground. However, it is unclear whether different conditions (footwear hardness or foot strike pattern) influence the accuracy and precision of different FS detection methods
[...] Read more.
Accelerometers and gyroscopes are used to detect foot strike (FS), i.e., the moment when the foot first touches the ground. However, it is unclear whether different conditions (footwear hardness or foot strike pattern) influence the accuracy and precision of different FS detection methods when using such micro-electromechanical sensors (MEMS). This study compared the accuracy of four published MEMS-based FS detection methods with each other and the gold standard (force plate) to establish the most accurate method with regard to different foot strike patterns and footwear conditions. Twenty-three recreational runners (12 rearfoot and 11 forefoot strikers) ran on a 15-m indoor track at their individual running speed in three footwear conditions (low to high hardness). MEMS and a force plate were sampled at a rate of 3750 Hz. Individual accuracy and precision of FS detection methods were found which were dependent on running styles and footwear conditions. Most of the methods were characterized by a delay which generally increased from rearfoot to forefoot strike pattern and from high to low midsole hardness. It can be concluded that only one of the four methods can accurately determine FS in a variety of conditions. Full article
Figures

Graphical abstract

Open AccessArticle Gas Sensor Design Based on a Line Locked Tunable Fiber Laser and the Dual Path Correlation Spectroscopy Method
Appl. Sci. 2017, 7(9), 958; https://doi.org/10.3390/app7090958
Received: 9 August 2017 / Revised: 9 September 2017 / Accepted: 18 September 2017 / Published: 19 September 2017
Cited by 1 | PDF Full-text (594 KB) | HTML Full-text | XML Full-text
Abstract
In this work a hybrid gas sensor based on a tunable fiber laser and a correlation spectroscopy technique is presented. The laser is tuned by varying the temperature of a bulk silicon wafer of 85 μm thickness and, once the desired wavelength
[...] Read more.
In this work a hybrid gas sensor based on a tunable fiber laser and a correlation spectroscopy technique is presented. The laser is tuned by varying the temperature of a bulk silicon wafer of 85 μ m thickness and, once the desired wavelength is reached the line, is locked by keeping fixed its temperature. According to experimental results the wafer temperature variation was in the order of 0.02 K, which induced an estimated wavelength deviation of 0.12 pm, which satisfies the high wavelength position accuracy required for gas sensing applications. Additionally, it is shown that errors due to laser intensity fluctuations can be minimized by implementing a simple dual path correlation spectroscopy stage. As a proof of the suitability of our tunable fiber laser for gas sensing applications, a C2H2 sensor was implemented. By using a 10 cm gas cell at atmospheric pressure, it was possible to detect concentrations from 0 to 20% with a sensitivity of 521 ppm and sub-minute time response. Moreover, the experimental measurements and simulated results have a high level of agreement. Finally, it is important to point out that, by using doped fiber with different characteristics, other wavelength emissions can be generated. Full article
(This article belongs to the Section Optics and Lasers)
Figures

Figure 1

Open AccessArticle An On-Line Oxygen Forecasting System for Waterless Live Transportation of Flatfish Based on Feature Clustering
Appl. Sci. 2017, 7(9), 957; https://doi.org/10.3390/app7090957
Received: 31 July 2017 / Revised: 4 September 2017 / Accepted: 12 September 2017 / Published: 18 September 2017
Cited by 1 | PDF Full-text (4026 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Accurate prediction of forthcoming oxygen concentration during waterless live fish transportation plays a key role in reducing the abnormal occurrence, increasing the survival rate in delivery operations, and optimizing manufacturing costs. The most effective ambient monitoring techniques that are based on the analysis
[...] Read more.
Accurate prediction of forthcoming oxygen concentration during waterless live fish transportation plays a key role in reducing the abnormal occurrence, increasing the survival rate in delivery operations, and optimizing manufacturing costs. The most effective ambient monitoring techniques that are based on the analysis of historical process data when performing forecasting operations do not fully consider current ambient influence. This is likely lead to a greater deviation in on-line oxygen level forecasting in real situations. Therefore, it is not advisable for the system to perform early warning and on-line air adjustment in delivery. In this paper, we propose a hybrid method and its implementation system that combines a gray model (GM (1, 1)) with least squares support vector machines (LSSVM) that can be used effectively as a forecasting model to perform early warning effectively according to the dynamic changes of oxygen in a closed system. For accurately forecasting of the oxygen level, the fuzzy C-means clustering (FCM) algorithm was utilized for classification according to the flatfish’s physical features—i.e., length and weight—for more pertinent training. The performance of the gray model-particle swarm optimization-least squares support vector machines (GM-PSO-LSSVM) model was compared with the traditional modeling approaches of GM (1, 1) and LSSVM by applying it to predict on-line oxygen level, and the results showed that its predictions were more accurate than those of the LSSVM and grey model. Therefore, it is a suitable and effective method for abnormal condition forecasting and timely control in the waterless live transportation of flatfish. Full article
Figures

Figure 1

Open AccessFeature PaperReview ECOAL Project—Delivering Solutions for Integrated Monitoring of Coal-Related Fires Supported on Optical Fiber Sensing Technology
Appl. Sci. 2017, 7(9), 956; https://doi.org/10.3390/app7090956
Received: 31 July 2017 / Revised: 12 September 2017 / Accepted: 13 September 2017 / Published: 16 September 2017
PDF Full-text (7175 KB) | HTML Full-text | XML Full-text
Abstract
The combustion of coal wastes resulting from mining is of particular environmental concern, and the importance of proper management involving real-time assessment of their status and identification of probable evolution scenarios is recognized. Continuous monitoring of the combustion temperature and emission levels of
[...] Read more.
The combustion of coal wastes resulting from mining is of particular environmental concern, and the importance of proper management involving real-time assessment of their status and identification of probable evolution scenarios is recognized. Continuous monitoring of the combustion temperature and emission levels of certain gases allows for the possibility of planning corrective actions to minimize their negative impact on the surroundings. Optical fiber technology is well suited to this purpose and here we describe the main attributes and results obtained from a fiber optic sensing system projected to gather data on distributed temperature and gas emissions in these harsh environments. Full article
(This article belongs to the Special Issue Distributed Optical Fiber Sensors)
Figures

Figure 1

Open AccessFeature PaperArticle CO2 with Mechanical Subcooling vs. CO2 Cascade Cycles for Medium Temperature Commercial Refrigeration Applications Thermodynamic Analysis
Appl. Sci. 2017, 7(9), 955; https://doi.org/10.3390/app7090955
Received: 24 July 2017 / Revised: 4 September 2017 / Accepted: 11 September 2017 / Published: 16 September 2017
Cited by 1 | PDF Full-text (6069 KB) | HTML Full-text | XML Full-text
Abstract
A recent trend to spread the use of CO2 refrigeration cycles in warm regions of the world is to combine a CO2 cycle with another one using a high performance refrigerant. Two alternatives are being considered: cascade and mechanical subcooling systems.
[...] Read more.
A recent trend to spread the use of CO2 refrigeration cycles in warm regions of the world is to combine a CO2 cycle with another one using a high performance refrigerant. Two alternatives are being considered: cascade and mechanical subcooling systems. Both respond to a similar configuration of the refrigeration cycle, they being based on the use of two compressors and same number of heat exchangers. However, the compressor, heat exchanger sizes and energy performance differ a lot between them. This work, using experimental relations for CO2 and R1234yf semi-hermetic compressors analyzes in depth both alternatives under the warm climate of Spain. In general, it was concluded that the CO2 refrigeration solution with mechanical subcooling would cover all the conditions with high overall energy efficiency, thus it being recommended for further extension of the CO2 refrigeration applications. Full article
(This article belongs to the Section Mechanical Engineering)
Figures

Figure 1

Open AccessArticle Computational Algorithms Underlying the Time-Based Detection of Sudden Cardiac Arrest via Electrocardiographic Markers
Appl. Sci. 2017, 7(9), 954; https://doi.org/10.3390/app7090954
Received: 17 August 2017 / Revised: 9 September 2017 / Accepted: 14 September 2017 / Published: 16 September 2017
Cited by 1 | PDF Full-text (7403 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Early detection of sudden cardiac arrest (SCA) is critical to prevent serious repercussion such as irreversible neurological damage and death. Currently, the most effective method involves analyzing electrocardiogram (ECG) features obtained during ventricular fibrillation. In this study, data from 10 normal patients and
[...] Read more.
Early detection of sudden cardiac arrest (SCA) is critical to prevent serious repercussion such as irreversible neurological damage and death. Currently, the most effective method involves analyzing electrocardiogram (ECG) features obtained during ventricular fibrillation. In this study, data from 10 normal patients and 10 SCA patients obtained from Physiobank were used to statistically compare features, such as heart rate, R-R interval duration, and heart rate variability (HRV) features from which the HRV features were then selected for classification via linear discriminant analysis (LDA) and linear and fine Gaussian support vector machines (SVM) in order to determine the ideal time-frame in which SCA can be accurately detected. The best accuracy was obtained at 2 and 8 min prior to SCA onset across all three classifiers. However, accuracy rates of 75–80% were also obtained at time-frames as early as 50 and 40 min prior to SCA onset. These results are clinically important in the field of SCA, as early detection improves overall patient survival. Full article
(This article belongs to the Section Computer Science and Electrical Engineering)
Figures

Figure 1

Open AccessArticle Pt-Based Nanostructures for Observing Genuine SERS Spectra of p-Aminothiophenol (PATP) Molecules
Appl. Sci. 2017, 7(9), 953; https://doi.org/10.3390/app7090953
Received: 15 August 2017 / Revised: 9 September 2017 / Accepted: 9 September 2017 / Published: 15 September 2017
PDF Full-text (4234 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
By one-pot wet chemical method, Pt-based hollow nanostructures were synthesized at room temperature. Because of the highly damping optical response of the metal, these Pt-based hollow nanostructures exhibited weak thermal effects with a laser focal spot on 4-aminothiophenol (PATP) molecules limiting dimerisation. The
[...] Read more.
By one-pot wet chemical method, Pt-based hollow nanostructures were synthesized at room temperature. Because of the highly damping optical response of the metal, these Pt-based hollow nanostructures exhibited weak thermal effects with a laser focal spot on 4-aminothiophenol (PATP) molecules limiting dimerisation. The isolated surface enhanced Raman scattering (SERS) spectra of PATP, in which the vibrational bands from 4,4′-dimercaptoazobenzene (DMAB) molecules are not observed, were able to be seen, and this was in good agreement with the Raman spectra of PATP powder. In addition, the concentration of PATP molecules was varied, and the illumination time was increased to 2000 s, respectively. It was found that spectra were stable with varied PATP concentrations, and the plasmon-driven chemical conversion of PATP to DMAB was still suppressed, even when the laser illumination time was increased to 2000 s. Full article
(This article belongs to the Special Issue Laser Interaction with Plasmonic Nanostructures)
Figures

Graphical abstract

Open AccessArticle Study on the High Temperature Interfacial Stability of Ti/Mo/Yb0.3Co4Sb12 Thermoelectric Joints
Appl. Sci. 2017, 7(9), 952; https://doi.org/10.3390/app7090952
Received: 31 August 2017 / Revised: 12 September 2017 / Accepted: 13 September 2017 / Published: 15 September 2017
PDF Full-text (3840 KB) | HTML Full-text | XML Full-text
Abstract
To improve the interfacial stability at high temperatures, n-type skutterudite (SKD) thermoelectric joints with sandwich structures of Ti/Mo/Yb0.3Co4Sb12 were successfully designed and fabricated. In this structure, Mo and Ti were introduced as the barrier layer with the
[...] Read more.
To improve the interfacial stability at high temperatures, n-type skutterudite (SKD) thermoelectric joints with sandwich structures of Ti/Mo/Yb0.3Co4Sb12 were successfully designed and fabricated. In this structure, Mo and Ti were introduced as the barrier layer with the goal of suppressing the interfacial diffusion and the buffer layer with the goal of enhancing the bonding strength, respectively. To evaluate the high temperature interfacial behavior of the Ti/Mo/Yb0.3Co4Sb12 joints, thermal shocking between 0 °C and 600 °C and isothermal aging at a temperature range of 550 °C to 650 °C were carried out in vacuum. During the isothermal aging process, Ti penetrates across the Mo layer, and finally diffuses into the Yb0.3Co4Sb12 matrix. By increasing the isothermal aging time, Ti continuously diffuses and reacts with the elements of Sb and Co in the matrix, consequently forming the multilayer-structured intermetallic compounds of Ti3Sb/Ti2Sb/TiCoSb. Diffusion kinetics was investigated and it was found that the interfacial evolution of the Ti/Mo/Yb0.3Co4Sb12 joints was a diffusion-controlling process. During the diffusion process, the formed Mo-Ti buffer layer acts as a damper, which greatly decelerates the diffusion of Ti towards the Yb0.3Co4Sb12 matrix at high temperatures. Meanwhile, it was found that the increase in the contact resistivity of the joints mainly derives from the inter-diffusion between Ti and Yb0.3Co4Sb12. As a result, the Ti/Mo/Yb0.3Co4Sb12 joint demonstrates the excellent stability of the interfacial contact resistivity. Service life prediction was made based on the stability of the contact resistivity, and it was found that the Ti/Mo/Yb0.3Co4Sb12 joint is qualified for practical applications at 550 °C. Full article
Figures

Graphical abstract

Open AccessArticle Practical Challenge of Shredded Documents: Clustering of Chinese Homologous Pieces
Appl. Sci. 2017, 7(9), 951; https://doi.org/10.3390/app7090951
Received: 20 July 2017 / Revised: 7 September 2017 / Accepted: 12 September 2017 / Published: 15 September 2017
PDF Full-text (4657 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
When recovering a shredded document that has numerous mixed pieces, the difficulty of the recovery process can be reduced by clustering, which is a method of grouping pieces that originally belonged to the same page. Restoring homologous shredded documents (pieces from different pages
[...] Read more.
When recovering a shredded document that has numerous mixed pieces, the difficulty of the recovery process can be reduced by clustering, which is a method of grouping pieces that originally belonged to the same page. Restoring homologous shredded documents (pieces from different pages of the same file) is a frequent problem, and because these pieces have nearly indistinguishable visual characteristics, grouping them is extremely difficult. Clustering research has important practical significance for document recovery because homologous pieces are ubiquitous. Because of the wide usage of Chinese and the huge demand for Chinese shredded document recovery, our research focuses on Chinese homologous pieces. In this paper, we propose a method of completely clustering Chinese homologous pieces in which the distribution features of the characters in the pieces and the document layout are used to correlate adjacent pieces and cluster them in different areas of a document. The experimental results show that the proposed method has a good clustering effect on real pieces. For the dataset containing 10 page documents (a total of 462 pieces), its average accuracy is 97.19%. Full article
(This article belongs to the Section Computer Science and Electrical Engineering)
Figures

Figure 1

Open AccessArticle Decision Support Simulation Method for Process Improvement of Intermittent Production Systems
Appl. Sci. 2017, 7(9), 950; https://doi.org/10.3390/app7090950
Received: 20 August 2017 / Revised: 2 September 2017 / Accepted: 13 September 2017 / Published: 15 September 2017
Cited by 1 | PDF Full-text (2870 KB) | HTML Full-text | XML Full-text
Abstract
Nowadays production system processes are undergoing sweeping changes. The trends include an increase in the number of product variants to be produced, as well as the reduction of the production’s lead time. These trends were induced by new devices of the industry’s 4.0,
[...] Read more.
Nowadays production system processes are undergoing sweeping changes. The trends include an increase in the number of product variants to be produced, as well as the reduction of the production’s lead time. These trends were induced by new devices of the industry’s 4.0, namely the Internet of Things and cyber physical systems. The companies have been applying intermittent production systems (job production, batch production) because of the increase in the number of product variants. Consequently, increasing the efficiency of these systems has become especially important. The aim of development in the long term—not achievable in many cases—is the realization of unique production, with mass production’s productivity and lower cost. The improvement of complex production systems can be realized efficiently only through simulation modeling. A standardized simulation method for intermittent production systems has not been elaborated so far. In this paper, I introduce a simulation method for system improvement and present its application possibilities and a practical example. Full article
(This article belongs to the Special Issue Modeling, Simulation, Operation and Control of Discrete Event Systems)
Figures

Figure 1

Open AccessArticle Stochastic Investigation of Consolidation Process in Spatially Correlated Heterogeneous Soils
Appl. Sci. 2017, 7(9), 949; https://doi.org/10.3390/app7090949
Received: 22 August 2017 / Revised: 12 September 2017 / Accepted: 13 September 2017 / Published: 15 September 2017
PDF Full-text (3835 KB) | HTML Full-text | XML Full-text
Abstract
Soil consolidation as the dissipation of excess pore water pressure is mainly affected by the relative hydraulic conductivity among the layers. Geostatistical parameters such as the mean, the standard deviation, and the correlation length are physical indicators for each sedimentation and formation history.
[...] Read more.
Soil consolidation as the dissipation of excess pore water pressure is mainly affected by the relative hydraulic conductivity among the layers. Geostatistical parameters such as the mean, the standard deviation, and the correlation length are physical indicators for each sedimentation and formation history. The effects of spatial variability on the excessive pore water pressure dissipation during consolidation process are investigated using numerical parametric studies, where multiple realizations are tested for selected hydraulic conductivity parameter using lognormal distribution. Numerical simulations show that the greater heterogeneity in hydraulic conductivity distribution applied, the longer time taken for the excess pore water pressure to dissipate, and the longer correlated variability encourages the greater variation in consolidation time. Such differences can be reduced significantly with the coupled drainage allowed by vertical drain method. Full article
Figures

Figure 1

Open AccessArticle On the Optimisation of Practical Wireless Indoor and Outdoor Microcells Subject to QoS Constraints
Appl. Sci. 2017, 7(9), 948; https://doi.org/10.3390/app7090948
Received: 24 July 2017 / Revised: 25 August 2017 / Accepted: 13 September 2017 / Published: 15 September 2017
Cited by 1 | PDF Full-text (2279 KB) | HTML Full-text | XML Full-text
Abstract
Wireless indoor and outdoor microcells (WIOMs) have emerged as a promising means to deal with a high demand of mobile users for a variety of services. Over such heterogeneous networks, the deployment of WIOMs costs mobile/telecommunications company high capital expenditures and operating expenses.
[...] Read more.
Wireless indoor and outdoor microcells (WIOMs) have emerged as a promising means to deal with a high demand of mobile users for a variety of services. Over such heterogeneous networks, the deployment of WIOMs costs mobile/telecommunications company high capital expenditures and operating expenses. This paper aims at optimising the WIOMs taking into account various network communication environments. We first develop an optimisation problem to minimise the number of cells as well as determining their optimal locations subject to the constraints of the coverage and quality-of-service (QoS) requirements. In particular, we propose a binary-search based cell positioning (BSCP) algorithm to find the optimal number of cells given a preset candidate antenna positions. The proposed BSCP algorithm is shown to not only reduce the number of cells for saving resources but also requires a low computational complexity compared to the conventional approaches with exhaustive search over all available sites. Moreover, EDX SignalPro is exploited as a simulation platform to verify the effectiveness of the proposed BSCP for the WIOMs with respect to various propagation modes and antenna parameters of different types, including isotropic, multiple-input single-output and multiple-input multiple-output. Full article
(This article belongs to the Section Computer Science and Electrical Engineering)
Figures

Figure 1

Back to Top