Bio-Inspired Filter Banks for SSVEP-based Brain-Computer Interfaces

Brain-computer interfaces (BCI) have the potential to play a vital role in future healthcare technologies by providing an alternative way of communication and control. More specifically, steady-state visual evoked potential (SSVEP) based BCIs have the advantage of higher accuracy and higher information transfer rate (ITR). In order to fully exploit the capabilities of such devices, it is necessary to understand the features of SSVEP and design the system considering its biological characteristics. This paper introduces bio-inspired filter banks (BIFB) for a novel SSVEP frequency detection method. It is known that SSVEP response to a flickering visual stimulus is frequency selective and gets weaker as the frequency of the stimuli increases. In the proposed approach, the gain and bandwidth of the filters are designed and tuned based on these characteristics while also incorporating harmonic SSVEP responses. This method not only improves the accuracy but also increases the available number of commands by allowing the use of stimuli frequencies elicit weak SSVEP responses. The BIFB method achieved reliable performance when tested on datasets available online and compared with two well-known SSVEP frequency detection methods, power spectral density analysis (PSDA) and canonical correlation analysis (CCA). The results show the potential of bio-inspired design which will be extended to include further SSVEP characteristic (e.g. time-domain waveform) for future SSVEP based BCIs.Comment: 2016 IEEE International Conference on Biomedical and Health Informatics (BHI

On Euclidean Norm Approximations

Euclidean norm calculations arise frequently in scientific and engineering applications. Several approximations for this norm with differing complexity and accuracy have been proposed in the literature. Earlier approaches were based on minimizing the maximum error. Recently, Seol and Cheun proposed an approximation based on minimizing the average error. In this paper, we first examine these approximations in detail, show that they fit into a single mathematical formulation, and compare their average and maximum errors. We then show that the maximum errors given by Seol and Cheun are significantly optimistic.Comment: 9 pages, 1 figure, Pattern Recognitio

The development of a harvest system for capsules of opium under laboratuary conditions

Bu çalışmada, laboratuar koşullarında çalışan bir haşhaş kapsül toplama sisteminin geliştirilmesi amaçlanmıştır. Bu amaçla, sistemin tasarımı ve sonlu elemanlar yöntemine göre gerilme analizleri bilgisayar destekli tasarım programı kullanılarak gerçekleştirilmiştir. Tasarım sonucunda imalatı gerçekleştirilen prototip sistemle, üç farklı ilerleme hızında (1, 1.5 ve 2 km/h), üç farklı tutucu tekerlek devir sayısında (70, 90 ve 110 min-1) ve sabit yedirici helezonun devir sayısında (510 min-1) laboratuar denemeleri yapılmıştır. Denemeler sonucunda sağlam haşhaş kapsül oranları, sap uzunlukları ve depoya ulaşan haşhaş kapsül oranları gibi kriterlere göre prototip sistemin performansı belirlenmiştir. Elde edilen bulgulardan çalışma sınırları içerisinde 3 farklı çalışma kombinasyonu ortaya çıkmıştır. Bu kombinasyonlar içerisinde en iyi sonuçlar; 1 km/h ilerleme hızı ve 70 min-1 tutucu tekerlek devrindeki depoya ulaşan haşhaş kapsül oranı (%98,08), 2 km/h ilerleme hızı ve 70 min-1 tutucu tekerlek devrindeki sap uzunlukları (5.30 cm) ve 2 km/h ilerleme hızı ile 90 min-1 tutucu tekerlek devrindeki sağlam haşhaş kapsül oranları (%99.35) optimum değerlerde elde edilmiş; kombinasyonlar uygulama maliyetleri ve iş başarısı yönünden karşılaştırılmıştır. Fire ve işçilik maliyetlerinin belirlenmesine yönelik olarak yapılan analiz sonuçlarına göre; 2 km/h ilerleme hızı ile 90 min-1 tutucu tekerlek devri koşullarında ve depoya ulaşmayan sağlam kapsüllerin toplanmasını içeren uygulama 25.09 TL/da ile en düşük değere sahip olmuştur. Laboratuar deneme sonuçları, prototipi geliştirilen bu haşhaş kapsül toplama sisteminin tasarım, imalat ve performans açısından başarılı olduğunu göstermiştir. Tarla koşullarında çalışacak kapsül toplama makinası geliştirilmesine öncülük edecek olan prototip haşhaş toplama sisteminin haşhaş tarımına olumlu katkıları beklenmektedir. Anahtar sözcükler: Haşhaş, Haşhaş Hasadı, Kapsül Toplama SistemiIn this study, it is aimed to develop the system of harvesting opium capsule. For this aim, tension analyses have been done through the method of Finite Elements using the computer based design program. With the prototype system whose production was put into action at the end of the design, the laboratory experiments have been done on three different travel speed (1, 1.5 and 2 km/h ), three different retainer wheel speed number (70, 90 and 110 min-1) and single feeder helix speed (510 min-1). According to the criteria of full opium capsule rates, the length of opium stalk and the rates of opium which have been put to depot the performance have been determined. Within the working limits, three different working combinations have turned out with the findings obtained. As a result, at the travel speed of 1 km/h, the rate of opium capsule reaching the depot in 70 min-1 retainer wheel cycle (%98.08) and at the travel speed of 2 km/h, the length of opium stalk in 70 min-1 retainer wheel cycle (5.30 cm) and also at the travel speed of 2 km/h and 90 min-1 retainer wheel cycle, the rate of undamaged opium capsule (%99.35) have been obtained. Then combinations have been compared in terms of cost and machine performance. According to the results of experiment analysis which have done to determine worker cost and wastage rate; the practice with which 2 km/h travel speed and 90 min-1 retainer wheel cycle and also contains picking up the full capsules that are fall down to out of depot, has the lowest cost with 25.09 TL/da in the name of total wastage and worker cost. It is expected that the prototype opium harvesting system, which will pioneer in the development of capsule picking machine designed to work in fields, will contribute greatly to opium agriculture. Key words: Opium, Opium Harvesting, Capsule Harvesting Syste

Cytoadherence and virulence - the case of Plasmodium knowlesi malaria.

BACKGROUND: Cytoadherence of infected red blood cells to brain endothelium is causally implicated in malarial coma, one of the severe manifestations of falciparum malaria. Cytoadherence is mediated by specific binding of variant parasite antigens, expressed on the surface of infected erythrocytes, to endothelial receptors including, ICAM-1, VCAM and CD36. In fatal cases of severe falciparum malaria with coma, blood vessels in the brain are characteristically congested with infected erythrocytes. Brain sections from a fatal case of knowlesi malaria, but without coma, were similarly congested with infected erythrocytes. The objective of this study was to determine the binding phenotype of Plasmodium knowlesi infected human erythrocytes to recombinant human ICAM-1, VCAM and CD36. METHODS: Five patients with PCR-confirmed P. knowlesi malaria were recruited into the study with consent between April and August 2010. Pre-treatment venous blood was washed and cultured ex vivo to increase the proportion of schizont-infected erythrocytes. Cultured blood was seeded into Petri dishes with triplicate areas coated with ICAM-1, VCAM and CD36. Following incubation at 37°C for one hour the dishes were washed and the number of infected erythrocytes bound/mm2 to PBS control areas and to recombinant human ICAM-1 VCAM and CD36 coated areas were recorded. Each assay was performed in duplicate. Assay performance was monitored with the Plasmodium falciparum clone HB3. RESULTS: Blood samples were cultured ex vivo for up to 14.5 h (mean 11.3 ± 1.9 h) to increase the relative proportion of mature trophozoite and schizont-infected red blood cells to at least 50% (mean 65.8 ± 17.51%). Three (60%) isolates bound significantly to ICAM-1 and VCAM, one (20%) isolate bound to VCAM and none of the five bound significantly to CD36. CONCLUSIONS: Plasmodium knowlesi infected erythrocytes from human subjects bind in a specific but variable manner to the inducible endothelial receptors ICAM-1 and VCAM. Binding to the constitutively-expressed endothelial receptor CD36 was not detected. Further work will be required to define the pathological consequences of these interactions

ARCHITECTURE AS A KNOWLEDGEBASED TOOL:: THE ARCHITECTURAL TRANSFORMATION OF WORKSPACES

In these early days of the twenty-first century the pace of innovations in technological developments is phenomenal. A common example: the personal computers that we were using five years ago – which did not even exist about twenty five years ago – are now –for all intents and purposes useless today. The speed of technological innovations and product development has reached such an extent that almost every one of us has some outdated "technological” tool, which is yet to be "upgraded” to the latest technology. While many disciplines are in constant state of inquiry – both for understanding the factors that necessitate these fast paced developments, and ways of supporting and utilizing the developments themselves, is architecture merely accommodating these technologies – i.e., is it simply a "spectator”? Or, can architecture be a discipline or realm to support these fast paced technological developments and innovations, - i.e., is it a "player”? Which role is more appropriate for architecture, or which positions for architects can highlight architecture as an important force of this era of constant and rapid technological change and development