Earticle

The Vehicle Routing Problem (VRP) is an important problem occurring in many distribution systems, which is also defined as a family of different versions such as the Capacitated Vehicle Routing Problem (CVRP) and the Vehicle Routing Problem with Time Windows (VRPTW). The Ant Colony Optimization (ACO) is a metaheuristic for combinatorial optimization problems. Given the ACO inadequacy, the vehicle routing optimization model is improved and the transfer of the algorithm in corresponding rules and the trajectory updated regulations is reset in this paper, which is called the Improved Ant Colony Optimization (I-ACO). Compared to the calculated results with genetic algorithm (GA) and particle swarm optimization (PSO), the correctness of the model and algorithm is verified. Experimental results show that the I-ACO can quickly and effectively obtain the optimal solution of VRFTW.

The present work deals with the automatic detection of the sleep stages from the single-channel EEG data. Various stages of sleep are Awake, sleep stage 1, 2, 3 and 4 and rapid eye movement. Statistical attributes are extracted with the help of Ensemble Empirical Mode Decomposition, Hjorth parameter and zero-crossing rate. Ten-cross fold classification process is followed after best ranked attribute selection. After attributes are selected, the data is classified using bagging classifier. Accuracies of 98.46%, 95.62%, 93.87%, 93.17% and 91.93% for two-stages, three-stages, four-stages, five-stages and six-stages classification respectively. This classifier can be used for the real life application due to higher accuracies.

In order to locate damage posotion and quantify damage degree of transmission tower, the method of damage identification of transmission tower based on flexibility matrix and signalterm amplitude vector was proposed, by combining flexibility matrix method of damage identification and time-frequency analysis method of domain vibration signal. Firstly, the coefficient equation about modal parameters and damage parameters was established, according to the linear relationship between flexibility matrix elements and structure parameters. Then, by Wigner-Ville Distribution (WVD) signalterm analytical deduction of free vibration response of the damping structure, the responding function relation between signalterm amplitude and model parameters was founded. Finally, the coefficient equation was solved by substituting mode shape vector with signalterm amplitude vector, avoiding the structural modal parameters identification, the damage location and extent of transmission tower was detected once and for all. The numerical example analysis of single tower model and tower-line system shows that, the proposed method with good anti-noise performance can accurately detect the extent of single or multiple damage of current structure by a single measurement.

Aiming at the problem of extracting steady-state data automatically and rapidly from the process data which contains outliers, a rapid steady-state data extracting method fusing outliers detection based on automatic piecewise curve fitting is proposed. Firstly, the method carries out outliers detection according to local deviation and replaces it with grey theory. Then the noise is minimized through sliding mean filter and the quasi-steady-state data is extracted rapidly by involved rules. Lastly, the quasi-steady-state data is further judged by automatic piecewise curve fitting. The simulation test shows that the proposed method can not only eliminate the effect of outliers and noise, but also extract the steady-state data conforming to human’s experience quickly and efficiently.

The rapid evaluation of image manipulation and tampering has evoked the need for protecting digital data. Therefore a copyright protection method is used to protect the user information known as watermarking. Watermarking is the major image processing technique used to authenticate digital data. In this paper a hybrid approach is proposed to protect the digital data and also authenticates the user information. The proposed approach is an improvement over traditional video watermarking approaches. It uses fractions from the watermarked image to embed into the unique frames of the original video. The whole approach is divided into three steps which are described in the next sections of this paper. To check the resilience and robustness of this approach, various attacks are implemented over the watermarked video. After attacks, watermark image is extracted from the watermarked video to check the robustness of this approach. The quality of the recovered watermarked image is analysed using bit error rate. Experimental results show that this approach is very robust compared to other approaches.

In order to increase the recognition rate of the CT image of benign or malignant pulmonary nodules, Support vector machine (SVM) was adopted to classify them. Meanwhile, Particle swarm optimization (PSO) algorithm is used to optimize parameters of the kernel function of SVM. Various optimization results were acquired through multiple methods such as consistent inertia weight, linear decreasing inertia weight, first increasing and then decreasing inertia weight and non-linear decreasing inertia weight. As was proved by experiments, recognition rates of these methods in training set were the same. The method with consistent inertia weight had a short optimizing time, but recognition rate in test set was low. The remaining methods had a long optimizing time while recognition effects were better in test set.

Recent technology advancement in smartphones makes it the most important device in daily life communication. Instant messenger (IM) applications (apps) such as WhatsApp, WeChat, Viber and QQ messenger are gaining users demand for communication. We take data collected from WeChat and QQ which are most popular IM application as an example to investigate their traffic pattern. Based on our experimental findings, group chat messages take a larger portion in our data collected messages. We find users experiencing shorter battery life after group chat messages are in background traffic. In this paper, we look into improving group chat energy consumption. Our proposed energy efficient group chat messages support network preferences such as 3G or WiFi network. In addition, group chat traffic pattern is dependent on user status awareness, knowledge; we postponed messages over time while user is inactive and deliver postponed messages when user is active in group chats. We evaluate that our energy efficient group chat messaging achieves energy saving between 13.7% to 32% for 3G and 21% to 27% for WiFi, users.

Microstrip patch antennas have made great advancements in wireless communication field in recent years. They have many advantages like light weight, low cost, smaller size, easy fabrication, high data rates, and capability to operate at multiband and wideband. They can be directly printed on a PCB and are gaining popularity in mobile phones. As the demand of operational bands increases, the design procedure of microstrip antenna is becoming very difficult. The microstrip antenna must be compact in size to employ them in miniaturized portable devices. Microstrip antenna comprise of rectangle, square, circle, triangle, donut, and dipole shaped patches. This paper presents design and development of a microstrip patch antenna for multiband wireless applications. The proposed geometry contains a substrate having rectangular radiating patch with symmetrical E-shaped slots on one side and a ground plane on other side. The designed miniaturized antenna has dimensions of 25 x 25 x 1.58 mm. The performance parameters-operating frequency, return loss (S11), and voltage standing wave ratio (VSWR) are computed for the designed geometry. The fabricated antenna exhibits five frequency bands from 6.166 to 10.500 GHz. The computed return loss values are -14.9, -10.7, -14.3, -13.5 and -14.6 dB at frequencies 6.166, 6.833, 8.166, 9.500 and 10.500 GHz respectively. The observed VSWR values for the resonant frequency peaks are 1.43, 1.82, 1.48, 1.54 and 1.46 respectively. The values obtained for VSWR (between 1 and 2) and S11 (below -10dB) are within recommended range for the desired frequency bands. FR4 substrate is used for the fabrication of the antenna having permittivity of 4.4. The performance parameters of fabricated antenna geometry are computed using VNA tool.

The efficiency of spectral clustering depends heavily on the similarity measure adopted. A widely used similarity measure is the Gaussian kernel function where Euclidean distance is used. Unfortunately, the result of spectral clustering is very sensitive to the scaling parameter and the Euclidean distance is usually not suitable to the complex distribution data. In this paper, a spectral clustering algorithm based on fuzzy partition similarity measure ( FPSC) is presented to solve the problem that result of spectral clustering is very sensitive to scaling parameter. The proposed algorithm is steady extremely and hardly affected by the scaling parameter. Experiments on three benchmark datasets, two synthetic texture images are made, and the results demonstrate the effectiveness of the proposed algorithm.