Ghulam Ishaq Khan Institute of Engineering Sciences and Technology

About: Ghulam Ishaq Khan Institute of Engineering Sciences and Technology is a education organization based out in Topi, Pakistan. It is known for research contribution in the topics: Thin film & Quantum efficiency. The organization has 618 authors who have published 940 publications receiving 10674 citations.

Spectrum Occupancy and Residual Service Analysis in CRNs Using a Multi-Server Queueing Model

Abstract: Cognitive radio technology enables secondary users (SUs) to opportunistically access the unused or sparsely utilized spectrum by primary users (PUs) without causing any harmful interference to PUs. Consequently, spectrum occupancy modeling appears as an essential task in cognitive radio networks (CRNs). In this paper, we model spectrum occupancy using a queueing theory based approach in order to evaluate the performance of CRNs in terms of network capacity and number of cognitive radio users waiting for services etc. The queue adopted in this model has variable service capacity and can be considered as a multi-service queue with server failure where each channel acts as a server. When a channel is occupied by a PU, it is regarded as a server failure. Using the probability generating function, the closed-form expressions for various performance parameters are derived. Numerical results on the remaining services for SUs and the expected number of SUs as the CRN capacity varies are illustrated.

Role of samarium additions on the shape memory behavior of iron based alloys

Abstract: The effect of samarium contents on shape memory behavior of iron based shape memory alloys has been studied. It is found that the strength of the alloys increases with the increase in samarium contents. This effect can be attributed to the solid solution strengthening of austenite by samarium addition. It is also noticed that the shape memory effect increases with the increase in samarium contents. This improvement in shape memory effect presumably can be regarded as the effect of improvement in strength, increase in c / a ratio and obstruction of nucleation of ά in the microstructure.

Autonomous Unmanned Surface Vehicle a microcontroller based approach

Abstract: In today's technically advanced world autonomous systems are gaining rapid popularity. The goal of this project was to develop a system that could demonstrate this autonomy, as well as serve as a platform for future research work in the field of autonomous surface vehicles. The system presented is a powerful and relatively inexpensive Unmanned Surface Vehicle (USV). It brings about a combination of sensors integrated in such a way so as to provide simultaneous autonomous navigation, data acquisition and data transmission to base station through a wireless module. There is also a software interface developed to provide an interactive environment between the user and the system enabling the user to plan the path of the boat, upload the mission-plan into the system and to display real time data obtained from the sensors, speed of the boat and the battery health of the system.

Resistance Pressure Sensor Based on Ag/Cu2O-PEPC-NiPc/Al Composite

Abstract: This work reports on the fabrication and investigation of pressure sensor based on Ag/Cu2O-PEPC-NiPc/Al composite. The active layer of the composite was deposited by drop-casting of the blend Cu2O-PEPC-NiPc on flexible substrate. The thin film of the blend consist of cuprous oxide (Cu2O) micropowder, (5 wt. %), poly-N-epoxypropylcarbazole (PEPC), (2 wt. %) and nickel phthalocyanine (NiPc) micropowder, (3 wt. %) in benzol (1 ml). The film thickness of the composite is in the range of 20-30 μm. It is found that the fabricated sensor is sensitive to pressure and showed good repeatability. The decrease in resistance of the sensor is observed 10 times by increasing the external uniaxial pressure up to 11.7 kNm-2. The experimentally obtained results are compared with the simulated results and showed reasonable agreement with each other.