Search results for "Sensor"

Somatosensory System

2005

Integration of local features into a global shape

2001

AbstractIt is a well-established fact that the cortical filters selective for spatial frequency and orientation have a limited spatial extent. The present study investigated how information from local filters is integrated into global shapes. Specifically, we were interested in whether identification of a global pattern consisting of small oriented, spatially-bandpass features (Gabor patches) depends on the orientations of those features. The observer was presented with a C-like stimulus shape comprised of oriented Gabor elements on a blank background, and the performance measure was the threshold contrast for identifying the global orientation of the C-shape (four possible rotated orientat…

Nordic Comparison of 75-Year-Olds - Sensory and Psychomotor Functions

1993

Sensory and psychomotor functions were studied among 75-year-old men and women in three Nordic localities (Glostrup in Denmark, Gothenburg in Sweden, and Jyvaskyla in Finland) as part of a comparative study on functional capacity and health. Random samples were drawn from the population registers in Glostrup (n=550) and Gothenburg (n=450), whereas in Jyvaskyla all 75-year-old residents (n=388) were invited to participate in the study. Participation rates varied from 66.8% in Gothenburg to 79.1% in Jyvaskyla. Sensory functions studied included hearing (pure-tone thresholds at 125-8000 Hz), vision (visual acuity, refraction, intraocular pressure), balance (postural sway), and tactual sensitiv…

Measuring Heart Rate with a Heat Flux Sensor

2021

Different wearable biosignal measurement applications require minimally obtrusive and highly sensitive sensors and methods of transducing the heart pulse into an electric signal. At the same time, the sensors should have minimal power consumption and preferably provide information about more than just the heart rate. In this study, a method employing a heat flux sensor for recording the pulsatile cardiac component of an arterial pulse waveform is presented. The output signals of a conventional photoplethysmography (PPG) sensor and a heat flux sensor were recorded and compared with one another. The results show that a heat flux sensor can be used for measurement of heart pulse, in addition t…

Study of localized pulsed laser depassivation by interferometric probe

1997

Optical interferometry has been implemented as a novel approach to monitor sensitively the localized pulsed laser depassivation of iron or stainless steel samples. This new method, complementing the previous transient current measurements and channel flow double-electrode, is based on the time-resolved measurement of the rear surface displacement of the test sample induced by the laser generated ultrasonic wave. The removal of any material, such as the passive film, from the irradiated surface results in an enhancement of the longitudinal component of the laser generated ultrasonic wave, which is manifested in a change of the displacement characteristics of the rear surface of the test samp…

Defect detection in laser powder deposition components by laser thermography and laser ultrasonic inspections

2013

Laser Powder Deposition (LDP) techniques are being adopted within aerospace and automotive manufacturing to produce innovative precision components. Non-destructive techniques (NDT) for detecting and quantifying flaws within these components enables performance and acceptance criteria to be verified, improving product safety and reducing ongoing maintenance and product repair costs. In this work, software enabled techniques are presented for in-process analysis of NDT laser ultrasonic signals and pulsed laser thermography images of sequential metallic LPD layers. LPD tracks can be as thin as 200μm while deposited at a rate of 500 mm/min, requiring ultrafast inspection and processing times. …

GC sniffing analysis : olfactive intensity measurement by two methods

1995

The intensity perceived by sniffing after GC elution of six volatile compounds was measured by ten judges using two pieces of apparatus: a PC mouse which is moved on a 60-cm length scale and a rheostat apparatus which measures the finger span. The choice of the components mixed was influenced by purity, elution time, presence in food and known Steven's slopes. The histograms obtained by summing the responses (determined by measuring the areas under the peaks) of ten people show no significant differences between the two pieces of apparatus. Histograms realised in parallel by Charm analysis with three other judges showed great differences between subjects. However, the mean of the three Char…

3-4 gadīgu bērnu sensoro spēju attīstība vizuālajā mākslā pirmsskolā

2021

Bakalaura darba tēma “ 3-4 gadīgu bērnu sensoro spēju attīstība vizuālajā mākslā pirmsskolā” Cilvēka izpratne par apkārtējo pasauli sākas ar sajūtu un uztveres attīstību, kas rada nepieciešamos priekšnoteikumus. Uztveres un sajūtu attīstība veiksmīgāk notiek mērķtiecīgas, jēgpilnas darbības apstākļos (vizuālās mākslas nodarbībās), kas ne tikai rada labvēlīgus apstākļus sajūtu un uztveres attīstībai, bet arī rada nepieciešamību apgūt formu, krāsu un telpisko orientāciju. Bakalaura darba 1.nodaļā tiek aplūkota teorija par sensorajām spējām, kā arī autoru atziņas, viedokļi par sensoro spēju nepieciešamību un to attīstīšanu, pilnveidošanu. Lai varētu izprast sensoro spēju attīstības līmeni sāko…

A Context-Aware System for Ambient Assisted Living

2017

In the near future, the world's population will be characterized by an increasing average age, and consequently, the number of people requiring for a special household assistance will dramatically rise. In this scenario, smart homes will significantly help users to increase their quality of life, while maintaining a great level of autonomy. This paper presents a system for Ambient Assisted Living (AAL) capable of understanding context and user's behavior by exploiting data gathered by a pervasive sensor network. The knowledge inferred by adopting a Bayesian knowledge extraction approach is exploited to disambiguate the collected observations, making the AAL system able to detect and predict…

An Ambient Intelligence System for Assisted Living

2017

Nowadays, the population's average age is constantly increasing, and thus the need for specialized home assistance is on the rise. Smart homes especially tailored to meet elderly and disabled people's needs can help them maintaining their autonomy, whilst ensuring their safety and well-being. This paper proposes a complete context-aware system for Ambient Assisted Living (AAL), which infers user's actions and context, analyzing its past and current behavior to detect anomalies and prevent possible emergencies. The proposed system exploits Dynamic Bayesian Networks to merge raw data coming from heterogeneous sensors and infer user's behavior and health conditions. A rule-based reasoner is ab…