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Background: In WDM networks, there is a crucial need to monitor signal degradation factors in order to maintain the quality of transmission. This is more critical in dynamic optical networks as non-linear impairments are network state dependent. Moreover, PLIs are accumulative in nature, so the overall impact is increased tremendously as the length of signal path is increased. The interactions between different impairments along the path also influence their overall impact. Objective: Among the different impairments, the present work focuses on phase modulations owing to the intensities of signals themselves as well as the neighboring signals. It includes the influence of SPM, SPM and XPM, system parameters like signal power, wavelength and fiber parameters like attenuation coefficient, dispersion coefficient and their influence on Q-value and BER. Methods: The analysis is done through a single and two-channel transmitter system with varied power, wavelengths and system parameters. The corresponding optical spectrums are analysed. Results & Conclusion: It has been found that SPM and XPM pose broadening effect on spectrum without any effect on temporal distributions. The magnitude of signal power is among the parameters significantly influencing the broadening of spectrum. The higher the power, the more the magnitude of broadening. It has been found that in order to neglect the impact of input power; its magnitude must be kept below 20 mW. Also, the dispersion and attenuation value need to be carefully as they pose counteracting effect to SPM and XPM for certain values and hence can be used as compensation measures without any additional cost.

Background: Electrical Discharge Machining (EDM) has widely been used in manufacturing high strength and high hardness of metal material due to the EDM process, which is free from mechanical force. The control system, a core of the EDM machine tool, plays a major role in manufacturing high strength and high hardness metal material in terms of machining efficiency and machining quality of the process of EDM. Thus, more and more attention has been paid to the current trends of the control system of the EDM machine tool. Objective: To meet the increasing requirements of machining quality and machining efficiency in the EDM process, the control system of the EDM machine tool is being improved continuously. Methods: This paper reviews current various representative patents related to the control system of the EDM machine tool. Methods: This paper reviews current various representative patents related to the control system of the EDM machine tool. Results: By summarizing a large number of patents about the control system of the EDM machine tool, the parameter control system, the servo control system and the numerical control system of the EDM machine tool are analyzed, and the development trend of the EDM machine tool control system has been discussed. Conclusion: The optimization of the control system of the EDM machine tool is conducive to increasing machining efficiency and machining quality in the EDM process. More relevant patents will be invented in the future.

Background: Micro-Electrical Discharge Machining (EDM) milling is widely used in the processing of complex cavities and micro-three-dimensional structures, which is a more effective processing method for micro-precision parts. Thus, more attention has been paid on the micro-EDM milling. Objective : To meet the increasing requirement of machining quality and machining efficiency of micro- EDM milling, the processing devices and processing methods of micro-EDM milling are being improved continuously. Methods: This paper reviews various current representative patents related to the processing devices and processing methods of micro-EDM milling. Results: Through summarizing a large number of patents about processing devices and processing methods of micro-EDM milling, the main problems of current development, such as the strategy of electrode wear compensation and the development trends of processing devices and processing methods of micro-EDM milling are discussed. Conclusion: The optimization of processing devices and processing methods of micro-EDM milling are conducive to solving the problems of processing efficiency and quality. More relevant patents will be invented in the future.

Background: Electrical Discharge Machining (EDM) technique is an effective and reliable method for machining difficult-to-cut materials with complex shapes. Pulse power supply, a core component of the EDM machine tool, plays a major role in the processing efficiency and processing quality. Thus, more and more attention has been paid to the power types and control methods of pulse power supplies of EDM at present. Objective: To meet the increasing requirement of processing efficiency and processing quality of EDM, the power types and control methods of pulse power supplies are enhanced constantly. Methods: This paper sketches out various current representative patents relevant to the power types and control methods of pulse power supplies of EDM. Results: Through comparing the characteristics of the power types and control methods of pulse power supplies of EDM, the main problems in the present development such as low processing efficiency and poor processing quality are summarized and analyzed. Utilization and conservation of electric energy is also a concern. In addition, the further development tendency towards the power types and control methods of pulse power supplies of EDM is discussed. Conclusion: The optimization and development of the power types and control methods of pulse power supplies of EDM are beneficial to solve the problems of processing efficiency, processing quality and energy utilization in EDM. More interrelated patents on the pulse power supply of EDM will be invented later.

Background and Objective: Mobile Wireless Sensor Network (MWSN) is a specialized wireless network made up of large number of mobile sensors, where each sensor is capable of changing its location, relaying data to either the base station or neighbouring nodes. MWSN has emerged as a useful integral part of modern communication systems; however, its major performance challenges are lack of data delivery assurance due to mobility of its sensors, low computational power of its nodes, and some security related issues. Methods: Most of the existing WSN routing protocols are for non-mobile sensors and require considerably high computational power. Thus, not suitable for energy-constraint WSN with mobile sensors. Therefore, there is need for a secure protocol for MWSN with mechanisms that take into account the limited resources of the nodes and dynamism of its nodes’ locations. Results: In this paper, an efficient routing protocol for MWSN is proposed, not to only improve data delivery but to ensure reliability. This protocol is capable of selecting optimal multi-hop route among available routes for the source node and securely hops the data to the destination nodes through intermediary nodes. Formal and informal security analysis of the routing protocol is done to ascertain the required security level of the protocol. In addition, computational cost analysis is done to evaluate the computational cost of the protocol. Conclusion: The analysis results showed that the proposed protocol was secure and required low computational cost.

In the research of internet of things, considering power allocation of base station from the perspective of energy efficiency (EE) is very meaningful for ubiquitous power internet of things (UPIoT) optimization. In this paper, the EE of UPIoT was analyzed and a new method for internet optimization was proposed by adjusting the small cell transmits power. First, the UPIoT was modeled by two-tier homogeneous Poisson point process (PPP), and the coverage probability of base stations in each tier was derived. Second, according to the definition of EE, and the closed-form of EE was given by deriving the total power consumption and total throughput of UPIoT respectively. At last, the impact of the small cell transmission power on the EE of UPIoT was analyzed, and a small cell power optimization algorithm was proposed to maximize EE. Simulation results show that, the transmission power of cell has a significant impact on the EE of UPIoT. Furthermore, by optimizing the transmission power of small cell, the EE of UPIoT can be improved effectively.

There are two classical equations in the research field of granularity properties, commonly known as Gates-Gaudin-Schahamann granularity equation (referred to as GGS) and Rosin-Rammler-Sperling granularity equation(referred to as RRB). If we combine the RRB or GGS with the unified energy granularity equation, we can get the energy equation which is more close to the actual production. Through the analysis of the working mechanism, we can get the reason of energy saving and energy efficiency.