arXiv subjects

Abdurrachman Mappuji

Publications and source records attributed to Abdurrachman Mappuji.

2 recordsLinked to original sources

arXiv2016

PDM (Probes Distance Meter), Distance Measuring Instrument by Using Ultrasonic Propagation between Probes

The innovation process is always required to produce more advanced technology and increasing productivity. PDM (Probes Distance Meter) comes as a technological innovation in measurement, PDM is a digital distance measuring instrument uses a pair of probes. PDM consists of ultrasonic transducers, a microcontroller, and screen which shows the measurement result. PDM utilizes ultrasonic wave principle by using two probes as reference points. A microcontroller is used for performing calculation that uses the distance equation. Innovation and Excellence of PDM are simple, ergonomic, modern, and able to show the measurement result automatically. PDM has additional features those are the storage media to save the measurement result with a micro-SD card, sound generation, and braille for the blinds. Those tools are expected to be suitable for common people, academics, or technicians to perform the measurement. The results from the laboratory testing show that the prototype of PDM has resolution of 1 cm, full scale of 200 cm, 11.1% repeatability, 77.6% accuracy, and a nonlinearity parameter of 0.16%. PDM is in development and it is potential to be a model of digital measuring instrument in the future that is simple, fast, and its additional features are capable to be used by the blind.

physics.ins-det↗

arXiv2016

Study of Raspberry Pi 2 Quad-core Cortex A7 CPU Cluster as a Mini Supercomputer

High performance computing (HPC) devices is no longer exclusive for academic, R&D, or military purposes. The use of HPC device such as supercomputer now growing rapidly as some new area arise such as big data, and computer simulation. It makes the use of supercomputer more inclusive. Todays supercomputer has a huge computing power, but requires an enormous amount of energy to operate. In contrast a single board computer (SBC) such as Raspberry Pi has minimum computing power, but require a small amount of energy to operate, and as a bonus it is small and cheap. This paper covers the result of utilizing many Raspberry Pi 2 SBCs, a quad-core Cortex A7 900 MHz, as a cluster to compensate its computing power. The high performance linpack (HPL) is used to benchmark the computing power, and a power meter with resolution 10mV / 10mA is used to measure the power consumption. The experiment shows that the increase of number of cores in every SBC member in a cluster is not giving significant increase in computing power. This experiment give a recommendation that 4 nodes is a maximum number of nodes for SBC cluster based on the characteristic of computing performance and power consumption.

cs.DC↗