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Topic Review
Radio Direction Finder
A radio direction finder (RDF) is a device for finding the direction, or bearing, to a radio source. The act of measuring the direction is known as radio direction finding or sometimes simply direction finding (DF). Using two or more measurements from different locations, the location of an unknown transmitter can be determined; alternately, using two or more measurements of known transmitters, the location of a vehicle can be determined. RDF is widely used as a radio navigation system, especially with boats and aircraft. RDF systems can be used with any radio source, although the size of the receiver antennas are a function of the wavelength of the signal; very long wavelengths (low frequencies) require very large antennas, and are generally used only on ground-based systems. These wavelengths are nevertheless very useful for marine navigation as they can travel very long distances and "over the horizon", which is valuable for ships when the line-of-sight may be only a few tens of kilometres. For aircraft, where the horizon at altitude may extend to hundreds of kilometres, higher frequencies can be used, allowing much smaller antennas. An automatic direction finder, often capable of being tuned to commercial AM radio transmitters, is a feature of almost all modern aircraft. For the military, RDF systems are a key component of signals intelligence systems and methodologies. The ability to locate the position of an enemy transmitter has been invaluable since World War I, and it played a key role in World War II's Battle of the Atlantic. It is estimated that the UK's advanced "huff-duff" systems were directly or indirectly responsible for 24% of all U-boats sunk during the war. Modern systems often use phased array antennas to allow rapid beam forming for highly accurate results. These are generally integrated into a wider electronic warfare suite. Several distinct generations of RDF systems have been used over time, following new developments in electronics. Early systems used mechanically rotated antennas that compared signal strengths from different directions, and several electronic versions of the same concept followed. Modern systems use the comparison of phase or doppler techniques which are generally simpler to automate. Modern pseudo-Doppler direction finder systems consist of a number of small antennas fixed to a circular card, with all of the processing performed by software. Early British radar sets were also referred to as RDF, which was a deception tactic. However, the terminology was not inaccurate; the Chain Home systems used separate omnidirectional broadcasters and large RDF receivers to determine the location of the targets.
  • 2.2K
  • 10 Oct 2022
Topic Review
Measuring Grain Loss during Harvest in Paddy Field
A combine harvester has been widely employed for harvesting paddy in Malaysia. However, it is one of the most challenging machines to operate when harvesting grain crops. Improper handling of a combine harvester can lead to a significant amount of grain loss. Any losses during the harvesting process would result in less income for the farmers.
  • 2.2K
  • 28 Mar 2022
Topic Review
Geopolymers as Construction Materials
Utilising geopolymer as a construction material has gained institutional and commercial interest over the past decade, due to its favourable emissions profile as an alternative to carbon-intensive Ordinary Portland Cement-based concrete, which currently accounts for around 7% of global carbon emissions.
  • 2.2K
  • 11 May 2021
Topic Review
Industry 4.0 in Supply Chain
Industry 4.0 is better known as the fourth industrial revolution and describes a future production system’s vision. In 2011, the idea of Industry 4.0 was first given and implemented by the German government for supporting automation in manufacturing. The fourth industrial revolution (Industry 4.0) focuses on enabling automation to integrate all manufacturing industries’ systems to achieve sustainability. There are many disruptive technologies such as the Internet of things (IoT). This means that all the devices, machines, and processes in supply chains are digitally connected through an internet connection and share the real-time information of all the processes. The Internet of things (IoT) integrates different technologies such as sensors, networks, algorithms, and applications. The IoT enables businesses to improve their supply chain network and gain better productivity. Cyber–physical system (C.P.S.) is another fundamental technology of industry 4.0. C.P.S. can be implemented in many industries such as healthcare, logistics, and automobiles. From an operational view, logistics is the critical function of any business that engages the supply chain movements. A cyber-physical system allows the supply chain network to use networking, computation, and physical processes to add value in the production process to achieve competitiveness. Another concept of Industry 4.0 concerns automatic guided vehicles (A.G.V.), which are widely used by many companies.
  • 2.2K
  • 01 Sep 2021
Topic Review
Comet Lake
Comet Lake is Intel's codename for its 10th generation Core microprocessors. They are manufactured using Intel's third 14 nm Skylake process refinement, succeeding the Whiskey Lake U-series mobile processor and Coffee Lake desktop processor families. Intel announced low-power mobile Comet Lake-U CPUs on August 21, 2019, H-series mobile CPUs on April 2, 2020, desktop Comet Lake-S CPUs April 30, 2020, and Xeon W-1200 series workstation CPUs on May 13, 2020. Comet Lake processors and Ice Lake 10 nm processors are together branded as the Intel "10th Generation Core" family. Intel officially launched Comet Lake-Refresh CPUs on the same day as 11th Gen Core Rocket Lake launch. The low-power mobile Comet Lake-U Core and Celeron 5205U CPUs were discontinued on July 7, 2021.
  • 2.2K
  • 21 Nov 2022
Topic Review
Trailer Connectors in North America
A number of standards prevail in North America, or parts of it, for trailer connectors, the electrical connectors between vehicles and the trailers they tow that provide a means of control for the trailers.
  • 2.2K
  • 28 Oct 2022
Topic Review
Existing Reinforcement Concepts for 3D Printed Concrete
3D printed concrete (3DPC) technology is relatively new, and it still has many challenges to overcome if it is going to replace, at least in part, conventional concrete construction. One of the difficulties is the lack of proper reinforcement for printing building scale structures. Different ideas proposed to reinforce 3D printed concrete can be categorized based on the material (e.g., steel, thermoplastic, FRP, and other materials) or stage to place reinforcement (pre-installed, in-process, and post-installed reinforcement). However, limited available test data and even fewer examples of the use of the proposed reinforcement concepts in actual construction have retarded the development of this advanced technology. Before developing some novel concepts, looking back to review what has been achieved in this regard is a necessary step to move forward. This section will discuss the recent attempts to reinforce 3D printed concrete based on different stages to place the reinforcement.
  • 2.2K
  • 28 Mar 2022
Topic Review
Human–Machine Relationship
The human–machine relationship was dictated by human needs and what technology was available at the time. Changes within this relationship are illustrated by successive industrial revolutions as well as changes in manufacturing paradigms.  
  • 2.2K
  • 22 Feb 2023
Topic Review
Permanent Magnet Machines for High-Speed Applications
High-speed electrical machines have been extensively researched in the last few decades for industrial and domestic applications, including compressors, vacuum pumps, turbine generators, machine tools, flywheel energy storages, and so on. Compared with low-speed and moderate-speed conventional electrical machines, high-speed electrical machines offer advantages such as high-power density, small size, and light weight. More importantly, high-speed electrical machines can be directly connected to high-speed loads, and conventional gear boxes are no longer needed, which avoids complex gear box systems, improves system efficiency and reliability, and reduces system vibration, noise, and cost. With the evolution in the field of power electronics converters, the problems of high frequency supplies, required for high-speed operation, is no longer a restriction. The development of high-speed electrical machines is also supported by the development of high-speed bearing systems with high robustness, fewer losses, and longer lifetime.
  • 2.2K
  • 17 Jan 2022
Topic Review
Hybrid Prognostic Approaches of Aircraft Systems and Components
Prognostic and health management (PHM) plays a vital role in ensuring the safety and reliability of aircraft systems. The process entails the proactive surveillance and evaluation of the state and functional effectiveness of crucial subsystems. The principal aim of PHM is to predict the remaining useful life (RUL) of subsystems and proactively mitigate future breakdowns in order to minimize consequences. The achievement of this objective is helped by employing predictive modeling techniques and doing real-time data analysis. The incorporation of prognostic methodologies is of utmost importance in the execution of condition-based maintenance (CBM), a strategic approach that emphasizes the prioritization of repairing components that have experienced quantifiable damage. Multiple methodologies are employed to support the advancement of prognostics for aviation systems, encompassing physics-based modeling, data-driven techniques, and hybrid prognosis. 
  • 2.2K
  • 10 Oct 2023
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