RF MEMS Based Tunable Bowtie Shaped Substrate Integrated Waveguide Filter

A tunable bandpass filter based on a technique that utilizes substrate integrated waveguide (SIW) and double coupling is presented. The SIW based bandpass filter is implemented using a bowtie shaped resonator structure. The bowtie shaped filter exhibits similar performance as found in rectangular and circular shaped SIW based bandpass filters. This concept reduces the circuit foot print of SIW; along with miniaturization high quality factor is maintained by the structure. The design methodology for single-pole triangular resonator structure is presented. Two different inter-resonator couplings of the resonators are incorporated in the design of the two-pole bowtie shaped SIW bandpass filter, and switching between the two couplings using a packaged RF MEMS switch delivers the tunable filter. A tunning of 1 GHz is achieved for two frequency states of 6.3 and 7.3 GHz. The total size of the circuit is 70mm x 36mm x 0.787 mm (LxWxH)

Implimentation of Evolutionary Particle Swarm Optimization in Distributed Generation Sizing

The size of Distributed Generation (DG) is very important in order to reduce the impact of installing a DG in the distribution Network. Without proper connection and sizing of DG, it will cause the power loss to increase and also might cause the voltage in the network to operate beyond the acceptable limit. Therefore, most researchers have concentrated on the optimization technique to regulate the DG’s output to compute its optimal size. In this paper, the concept of Evolutionary Particle Swarm Optimization (EPSO) method is implemented in sizing the DG units. By substituting the concept of Evolutionary Programming (EP) in some part of Particle Swarm Optimization (PSO) algorithm process, it will make the process of convergence become faster. The algorithm has been tested in 33bus distribution system with 3 units of DG that operate in PV mode. Its performance was compared with the performance when using the traditional PSO and without using any optimization method. In terms of power loss reduction and voltage profile, the EPSO can give similar performance as PSO. Moreover, the EPSO requires less number of iteration and computing time to converge. Thus, it can be said that the EPSO is superior in term of speed, while maintaining the same performance.DOI:http://dx.doi.org/10.11591/ijece.v2i1.22

A Comparative Study for Different Sizing of Solar PV System under Net Energy Metering Scheme at University Buildings

Malaysia has moved forward by promoting the use of renewable energy such as solar PV to the public to reduce dependency on fossil fuel-based energy resources. Due to the concern on high electricity bill, Universiti Malaysia Perlis (UniMAP) is keen to install solar PV system as an initiative for energy saving program to its buildings. The objective of this paper is to technically and economically evaluate the different sizing of solar PV system for university buildings under the Net Energy Metering (NEM) scheme. The study involves gathering of solar energy resource information, daily load profile of the buildings, sizing PV array together with grid-connected inverters and the simulation of the designed system using PVsyst software. Based on the results obtained, the amount of solar energy generated and used by the load per year is between 5.10% and 20.20% from the total annual load demand. Almost all solar energy generated from the system will be self-consumed by the loads. In terms of profit gained, the university could reduce its electricity bill approximately between a quarter to one million ringgit per annum depending on the sizing capacity. Beneficially, the university could contribute to the environmental conservation by avoiding up to 2,000 tons of CO2 emission per year

Finite element analysis of composite cylinder with centre cutout under axial load and internal pressure

Results from Finite Element (FE) study on the response of composite cylinder shells with cutouts and subjected to internal pressure and axial compression are presented. The objective of the study is to improving the buckling load by applying the internal pressure whilst the compression load is applied. The effect of localized stress concentration distributed around the cutout region also being examined. The numerical results are obtained using ABAQUS finite element code software package. The composite cylinder shells were tested in two conditions which are a combination of axial compression load with internal pressure and a single axial compression load. The effects of varying internal pressure and cutout size on the pre-buckling, buckling, and post-buckling responses of the shell are demonstrated. Reasonable results comparison was obtained by reviewing previous literature. Results indicated that the load distribution and displacement of the cutout significantly influence the structural response of the shell. The results also indicate that the stress distributions can be affected by the size of the cutout under axial compression load

Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

A training monitoring system for cyclist based on wireless sensor networks

This paper presents a training monitoring system for cyclist that is based on the technology of wireless sensor networks (WSNs). A stable and reliable wireless cyclist monitoring system is vital to establish a smart and efficient sports management program. A training monitoring system has been developed and tested in a real cyclist training environment in a velodrome. The system is designed is such a way that the packet loss rate is minimum. Using TelG mote as the basis, customized sensor nodes that function as a forwarder node and the relay nodes are developed to form the WSN. This WSN is linked to the cloud network on the Internet. The cloud network is then established and end users application for data accessing is designed. Several experiments have been conducted in a real scenario in a velodrome to measure the reliability of the system architecture. It is shown from the experiments that the proposed system is reliable even when the cyclist is moving at a high speed. The packet loss is less than 2% which does not give a huge impact to the data transmission

A Review of Forensic Entomology Cases at Ipoh Hospital and Hospital Universiti Kebangsaan Malaysia for the Year 2003

Forensic entomology was utilized to determine the postmortem interval of eleven forensic cases sentfor autopsy examination at Ipoh Hospital and Hospital University Kebangsaan Malaysia between of Januaryto December 2003. Sixth species of sarcosaprophagous flies: Chrysomya megacephala, Chrysomya rufifacies,Chrysomya villeneuvi, Chrysomya nigripes, Synthesiomya nudiseta and a sarcophagid fly were found amongthe maggot specimens received by the Forensic Entomology Laboratory, Department of Parasitology &Medical Entomology, Universiti Kebangsaan Malaysia. Those maggots were collected from dead bodiesfound among others in wrapped in gunny bags, around water tank, hanged with black nylon clothes, insidehome, beside road, drowning in lombong and an estate. Ch. megacephala was the main species found in eightcases examined. Postmortem Interval (PMI) estimated from the cases varied from one day to 10 days

Embedded wireless stingless beehive monitoring and data management system

In this paper, an embedded wireless stingless bee monitoring system, which investigates the environment's temperature and humidity effect on the bee activity and honey production of Heterotrigona Itama, a stingless bee species, is presented. The variables observed by the system are the weight of the honey container, the temperature inside the hive, humidity inside the hive, temperature of the environment outside of the hive, the humidity of the environment outside of the hive, and bee activity counter. The sensors used are Strain Gauge Load Cell (SGLC) sensor for weighing purposes, DHT22 sensors for temperature and humidity, and infrared transceivers bee counter sensor for bee activity monitoring. All installed sensors were controlled by using a NodeMCU microcontroller. All data were recorded and transferred to a Google Firebase real-Time database. The proposed system offers an android application to access the recorded data called EMAS apps. EMAS fetches all the information from the database and represents it on graphs and pages in the user smart devices. This paper analyses the data obtained for 36 hours from a single hive. Results obtained represent a relationship between the temperature collected and bee activity with the honey produced. It was observed that in the morning, the increase of temperature leads to high traffic of bees going out of the hive, which decreases the weight of the hive to 2.7 Kg. Meanwhile, in the evening, the decrease in temperature leads to high traffic of bees going into the hive, which increases the hive weight to 4.5 Kg. For future work, to enhance the system's performance, installation of the embedded system into an array of hives was advised and longterm data observation process was required