VFDHSOG: Copy-Move Video Forgery Detection Using Histogram of Second Order Gradients

It is a generic belief that digital video can be proffered as visual evidence in areas like politics, criminal litigation, journalism and military intelligence services. Multicamera smartphones with megapixels of resolution are a common hand-held device used by everyone. This has made the task of video recording very easy. At the same time a variety of applications available on smart phones have made this indispensable source of information vulnerable to deliberate manipulations. Hence, content authentication of video evidence becomes essential. Copy-move forgery or Copy-paste forgery is consequential forgery done by forgers for changing the basic understanding of the scene. Removal or addition of frames in a video clip can also be managed by advanced apps on smartphones. In case of surveillance, the video camera and the background are stable which makes forgery easy and imperceptible. Therefore, accurate Video forgery detection is crucial. This paper proposes an efficient method—VFDHSOG based on Histograms of the second order gradient to locate ‘suspicious’ frames and then localize the CMF within the frame. A ‘suspicious’ frame is located by computing correlation coefficients of the HSOG feature after obtaining a binary image of a frame. Performance evaluation is done using the benchmark datasets Surrey university library for forensic analysis (SULFA), the Video tampering dataset (VTD) and SYSU-OBJFORGED dataset. SULFA has video files of different quality like q10, q20 etc., which represents high compression. The VTD dataset provides both, i.e. inter and intra frame forgery. The SYSU dataset covers different attacks like scaling and rotation. An overall accuracy of 92.26% is achieved with the capability to identify attacks like scale up/down and rotation.

     

Performance of new relay selection scheme for buffer-assisted multihop decode-and-forward networks

In this paper, a new relay selection scheme is proposed to reduce the end-to-end packet delivery delay for buffer-assisted multihop decode-and-forward cooperative networks. The proposed method selects a relay node having more packets in the associated buffer and relay's proximity to the destination node. Mathematical expressions for the outage probability and average packet delay in Rician fading are obtained by modeling the system as a Markov chain. The proposed relay selection scheme has less packet delay as compared to the max-link relay selection scheme with marginally higher outage probability. Thus, the proposed relay selection scheme is a good alternative to low latency wireless applications.     

Real‐Time Oil Painting on Mobile Hardware

This paper presents a realistic digital oil painting system, specifically targeted at the real‐time performance on highly resource‐constrained portable hardware such as tablets and iPads. To effectively use the limited computing power, we develop an efficient adaptation of the shallow water equations that models all the characteristic properties of oil paint. The pigments are stored in a multi‐layered structure to model the peculiar nature of pigment mixing in oil paint. The user experience ranges from thick shape‐retaining strokes to runny diluted paint that reacts naturally to the gravity set by tablet orientation. Finally, the paint is rendered in real time using a combination of carefully chosen efficient rendering techniques. The virtual lighting adapts to the tablet orientation, or alternatively, the front‐facing camera captures the lighting environment, which leads to a truly immersive user experience. Our proposed features are evaluated via a user study. In our experience, our system enables artists to quickly try out ideas and compositions anywhere when inspiration strikes, in a truly ubiquitous way. They do not need to carry expensive and messy oil paint supplies.     

Effective sparse imputation of patient conditions in electronic medical records for emergency risk predictions

Meta-clustering is a popular approach for finding multiple clusterings in the dataset, taking a large number of base clusterings as input for further user navigation and refinement. However, the effectiveness of meta-clustering is highly dependent on the distribution of the base clusterings and open challenges exist with regard to its stability and noise tolerance. In addition, the clustering views returned may not all be relevant, hence there is open challenge on how to rank those clustering views. In this paper we propose a simple and effective filtering algorithm that can be flexibly used in conjunction with any meta-clustering method. In addition, we propose an unsupervised method to rank the returned clustering views. We evaluate the framework (rFILTA) on both synthetic and real-world datasets, and see how its use can enhance the clustering view discovery for complex scenarios.     

An SVM—ANN Hybrid Classifier for Diagnosis of Gear Fault

A hybrid classifier obtained by hybridizing Support Vector Machines (SVM) and Artificial Neural Network (ANN) classifiers is presented here for diagnosis of gear faults. The distinctive features obtained from vibration signals of a running gearbox, which was operated in normal and fault-induced conditions, were used to feed the SVM-ANN hybrid classifier. Time-domain vibration signals were divided in segments. Features such as peaks in time domain and in spectrum, central moments, and standard deviations were obtained from signal segments. Based on the experimental results, it was shown that SVM-ANN hybrid classifier can successfully identify gear condition and that the hybrid SVM-ANN classifier performs much better than standard versions of ANNs and SVM. The effectiveness of the hybrid classifier under noise was also investigated. It was shown that if vibration signals are preprocessed by Discrete Wavelet Transform (DWT), efficacy of the SVM-ANN hybrid is significantly enhanced.     

Laser based optical sensor for vibration measurements

This paper presents a technique for detection and measurement of vibrations especially in machine design. This technique makes use of a He–Ne laser and has decisively an edge over the conventional methods, which have certain limitations regarding their vibration measurements due to their contact nature. However, in the present study, the method used is a non-contact one. In this case, the measurements include variation of voltage amplitude with rotor speed and variation of vibration frequency with rotor speed. Calibration studies are also conducted.     

Note: self Q-switched Nd:YVO4 laser at 914 nm

By exploiting the saturable nature of re-absorption loss under the quasi-three-level laser transition self Q-switching operation in Nd:YVO(4) laser at 914 nm is demonstrated. The stable self-pulsing operation was observed with Nd:YVO(4) crystal with doping concentration of 0.3 at.%. At an incident pump power of 30 W around 600 mW of average power was obtained. Individual pulse energy and FWHM pulse duration were experimentally measured to be 10 μJ and 460 ns, respectively. The performance of the laser was analyzed with the help of a rate equation model. The simulation results show good agreement with the experiment.     

Design and development of the magnetorheological abrasive flow finishing (MRAFF) process

A new precision finishing process for complex internal geometries using smart magnetorheological polishing fluid is developed. Magnetorheological abrasive flow finishing (MRAFF) process provides better control over rheological properties of abrasive laden magnetorheological finishing medium. Magnetorheological (MR) polishing fluid comprises of carbonyl iron powder and silicon carbide abrasives dispersed in the viscoplastic base of grease and mineral oil; it exhibits change in rheological behaviour in presence of external magnetic field. This smart behaviour of MR-polishing fluid is utilized to precisely control the finishing forces, hence final surface finish. A hydraulically powered experimental setup is designed to study the process characteristics and performance. The setup consists of two MR-polishing fluid cylinders, two hydraulic actuators, electromagnet, fixture and supporting frame. Experiments were conducted on stainless steel workpieces at different magnetic field strength to observe its effect on final surface finish. No measurable change in surface roughness is observed after finishing at zero magnetic field. However, for the same number of cycles the roughness reduces gradually with the increase of magnetic field. This validates the role of rheological behaviour of magnetorheological polishing fluid in performing finishing action.     

Solution Annealing of Super Duplex Stainless Steel: Correlating Corrosion Performance with Grain Size and Phase-Specific Chemistry

Metallurgical and Materials Transactions A - A super duplex stainless steel was subjected to solution annealing at 1323 K. This led to grain coarsening, ‘limited’ (~ 7 pct by...