Research Picks July 2015

Miners versus farmers in Ghana

Mining could be a major factor in food security in Ghana, according to researchers in Ghana and the USA. They have studied mining and agriculture for the period 1989 to 2007 and carried out a preliminary statistical analysis that lends support to the idea that mining has not led to a reduction in agricultural acreage increase despite expansion of mineral concession. They did find that there is evidence of a relationship between mining and a decline in maize, sorghum and cocoyam production. Real impacts of mining operations on agriculture may be more pronounced at the farming community or district level, the team reports. However, they subscribe to the hypothesis that “resource curse” occurs conditionally, and it may be offset by proactive policies and sufficiently good institutions being proactive in regulating both sectors.

Owusu-Ansah, F. and Smardon, R.C. (2015) ‘Mining and agriculture in Ghana: a contested terrain’, Int. J. Environment and Sustainable Development, Vol. 14, No. 4, pp.371–397.

Remote control lab-on-a-chip

Piezoelectric devices that can act as switches and actuators in so-called “lab-on-a-chip” technology, microelectromechanical systems (MEMS) could be very useful for running such devices and adding novel functionality for a range of industries where inexpensive, portable chemical analysis, medical diagnostics and more are needed. Piezolelectric materials change shape when a voltage is applied to them (conversely, they generate a voltage when squeezed). Researchers in India have now demonstrated what amounts to “remote control” for piezoelectric materials using magnetic resonant coupling to induce the shape-shifting without direct application of electricity to the piezoelectric material. Such a non-contact energy transfer system will be a boon to developers of MEMS as the problem of “wiring up” a piezoelectric actuator is removed from the requirements.

Nayak, P.P., Kar, D.P. and Bhuyan, S. (2014) ‘Energy transfer to piezoelectric component through magnetic resonant coupling’, Int. J. Nano and Biomaterials, Vol. 5. No. 4, pp.280–286.

Colorectal cancer clue

Colorectal cancer is a leading cause of cancer death in men and women. Now, a team from Jadavpur University, Kolkata, India, have developed a computer system that can identify the presence of polyps from still frames grabbed from a video colonoscopy. Polyps are often a feature of the precancerous colon. Their computer system reduces the amount of information needed to identify polyps automatically and can rapidly process still images from colonoscopy. Tests on images from optical colonoscopy video database provided by American College of Gastroenterology demonstrated proof of principle. The process works well offline, but now the team hopes to develop it further so that polyps can be identified while video colonoscopy is being carried out and so provide the medical professionals with an instantaneous warning of something untoward in the patient’s colon that could be treated sooner, rather than later.

Biswas, M. and Dey, D. (2015) ‘Hilbert-Huang transform-based video analysis for detecting colon polyps using composite similarity measure’, Int. J. Telemedicine and Clinical Practices, Vol. 1, No. 2, pp.141–156.

Parkinson’s disease detection

Early detection of Parkinson’s disease might be possible through analysis of the patient’s voice given that 9 out of 10 patients suffer symptoms that affect their voice early in the disease. Measurements of several vocal parameters such as pitch, jitteriness, shimmer, glottal pulse and intensity in healthy people and PD patients provides the necessary data to demonstrate an algorithm that can then analyze the vocal parameters of undiagnosed patients when they present early to a physician. Although there is no cure for PD, early treatment can stave off the worst symptoms for some time and improve quality of life for many patients.

Vikas and Sharma, R.K. (2015) ‘Analysis of voice for differentiating Parkinson’s disease affected persons from healthy persons’, Int. J. Telemedicine and Clinical Practices, Vol. 1, No. 2, pp.174–185.

Up, up and away in the name of science education

US researchers extol the virtues of high-altitude balloons for science education in a research paper published in the International Journal of Learning Technology. According to Jeremy Straub of the University of North Dakota in Grand Forks, “High-altitude balloons can carry student and scientific payloads to the boundaries of space.”

This, he suggests, gives students the opportunity to carry out experiments in a cold, near-vacuum, higher-radiation environment at such very high altitudes. “In the process, students experience the awe of space exploration as, through their payloads, they are able to view the curvature of the Earth and capture images as inspiring as those taken from the Space Shuttle or the International Space Station.” Moreover, experiments carried to high altitude in this way might help students to better grasp known principles or be original scientific experiments: allowing students to research and explore the unknown.

Straub suggests that high altitude balloons are ripe for exploitation in science education and beyond but that there is a need for a formal design framework for high-altitude ballooning. There is also a need for a framework to make this technology more effective in undergraduate university courses, for instance, through a standard approach to improving payload design.

“The function of a high-altitude balloon is incredibly simple: it lifts objects towards the upper boundary of the Earth’s atmosphere,” explains Straub. They are used on a twice-daily basis by some 700 weather-forecasting locations around the globe. Balloons have also been used to flight test spacesuits and other space technology and for various scientific endeavors, including simply dropping payloads to Earth for gravitational exploratory work, for example.

Such high-altitude balloons might reach altitudes of between 18 to 37 kilometers above the sea level, while record-holding balloons have stretched this reach to over 50 kilometers. “The rate at which it does this and how long it remains aloft are functions of the level of inflation and type of balloon chosen,” points out Straub. “While the functionality of the balloon may be simple, the learning results that can be attained vary significantly. The value of the balloon is the opportunity for access to near-space that it presents and the chance to enhance student creativity and enthusiasm.”

Straub, J. (2015) ‘Evaluation of high-altitude balloons as a learning technology‘, Int. J. Learning Technology, Vol. 10, No. 1, pp.94-110.

Pick of the pops

As yet another music streaming service comes online to rival the countless available outlets for so many different genres, a new approach to classifying music to make archiving, sorting and music discovery easier is published in the International Journal of Computational Intelligence Studies.

Rare is the musical artist described as genre-defying. Most singers and musicians, with a few notable exceptions, tend to stick to a particular style, whether electronic dance music, reggae, classical, folk, jazz, rock or Indian genres such as Bhangra and Ghazal, or any of hundreds of other categories. Listeners might categorize any given song into one of a few dozen genres with which they are familiar while dedicated fans of a specific genre may well distinguish between dozens of sub-genres within each classification. In the age of digital distribution and archiving of music and music recommendation systems it makes sense to have a way to automate the process of genre categorization.

Now, researchers in India have devised a simple system that, rather than attempting to quantify many different parameters – tempo, pulse, loudness, melody, rhythm, timbre etc – focuses on just pitch, tempo, amplitude variation pattern and periodicity in order to tag a given song as belonging to a specific genre. Their approach uses random sample consensus (RANSAC) as a classifier.

In the team’s approach their system decomposes, or breaks down, the sound signal into 88 frequency bands, divides each sub-band into short duration frames and for each frame, computes the short-time mean-square power (STMSP) and the average STMSP, this gives a metric for pitch. The team demonstrates that for seven major musical genres, this metric is very distinct. In order to be more precise, however, they also measure rhythm or tempo of a song, which is an important perceptual description essentially independent of melody. Tempo can be extracted from a sound file using a mathematical process known as a Fourier transform that gives the metric in beats per minute (BPM).

Pitch and tempo can both help decide on genre, but there is often overlap. For instance, these characteristics are often similar in North Indian Bhangra and Western rock music. So, another metric – amplitude variation – is also added to the mix. Additionally, the team also uses correlation-based periodicity. This is another perceptual feature which captures the repetitions within a given signal.

The team has now tested their genre identification system against earlier models by other researchers on a database of songs and then compared that to manual categorization. Their results show their system to be “substantially better” and it might readily be incorporated into a music database or online music recommendation service.

Ghosal, A., Chakraborty, R., Dhara, B.C. and Saha, S.K. (2015) ‘Perceptual feature-based song genre classification using RANSAC’, Int. J. Computational Intelligence Studies, Vol. 4, No. 1, pp.31–49.