Modified local discriminant bases algorithm and its application in analysis of human knee joint vibration signals

Knee joint disorders are common in the elderly population, athletes, and outdoor sports enthusiasts. These disorders are often painful and incapacitating. Vibration signals [vibroarthrographic (VAG)] are emitted at the knee joint during the swinging movement of the knee. These VAG signals contain information that can be used to characterize certain pathological aspects of the knee joint. In this paper, we present a noninvasive method for screening knee joint disorders using the VAG signals. The proposed approach uses wavelet packet decompositions and a modified local discriminant bases algorithm to analyze the VAG signals and to identify the highly discriminatory basis functions. We demonstrate the effectiveness of using a combination of multiple dissimilarity measures to arrive at the optimal set of discriminatory basis functions, thereby maximizing the classification accuracy. A database of 89 VAG signals containing 51 normal and 38 abnormal samples were used in this study. The features extracted from the coefficients of the selected basis functions were analyzed and classified using a linear-discriminant-analysis-based classifier. A classification accuracy as high as 80% was achieved using this true nonstationary signal analysis approach.     

Synthesis of α‐Arylphosphonates using Copper‐Catalyzed α‐Arylation and Deacylative α‐Arylation of β‐Ketophosphonates

Efficient methods for the direct arylation and deacylative arylation of β‐ketophosphonates with iodoarenes in presence of a copper(I) or a copper(II) salt as the catalysts have been developed. The corresponding α‐arylphosphonates were obtained in high yields. A tentative mechanism for the deacylative arylation reaction was proposed on the basis of the experimental data.     

Defected Ground Structure Multiple Input-Output Antenna For Wireless Applications

In this paper, the investigation of a novel compact 2 × 2, 2 × 1, and 1 × 1 Ultra-Wide Band (UWB) based Multiple-Input Multiple-Output (MIMO) antenna with Defected Ground Structure (DGS) is employed. The proposed Electromagnetic Radiation Structures (ERS) is composed of multiple radiating elements. These MIMO antennas are designed and analyzed with and without DGS. The feeding is introduced by a microstrip-fed line to significantly moderate the radiating structure’s overall size, which is 60 × 40 × 1 mm. The high directivity and divergence characteristics are attained by introducing the microstrip-fed lines perpendicular to each other. And the projected MIMO antenna structures are compared with others by using parameters like Return Loss (RL), Voltage Standing Wave Ratio (VSWR), Radiation Pattern (RP), radiation efficiency, and directivity. The same MIMO set-up is redesigned with DGS, and the resultant parameters are compared. Finally, the Multiple Input and Multiple Output Radiating Structures with and without DGS are compared for result considerations like RL, VSWR, RP, radiation efficiency, and directivity. This projected antenna displays an omnidirectional RP with moderate gain, which is highly recommended for human healthcare applications. By introducing the defected ground structure in bottom layer the lower cut-off frequencies of 2.3, 4.5 and 6.0 GHz are achieved with few biological effects on radio propagation in human body communications. The proposed design covers numerous well-known wireless standards, along with dual-function DGS slots, and it can be easily integrated into Wireless Body Area Networks (WBAN) in medical applications. This WBAN links the autonomous nodes that may be situated either in the clothes, on-body or beneath the skin of a person. This system typically advances the complete human body and the inter-connected nodes through a wireless communication channel.     

Effect of Silicon Carbide on Microstructural,Mechanical and Corrosion Behavior of Electrolytic Copper Matrix Composite Produced by the Powder Metallurgy Route

Silicon - In this work Copper based composites were synthesized from Cu and SiC powders using Powder Metallurgy (PM) technique. The composition of the composites are Cu, Cu-5 wt% SiC,...