Measuring close proximity interactions between individuals can provide key information on social contacts in human communities and related behaviours. This is even more essential in rural settings in ...low- and middle-income countries where there is a need to understand contact patterns for the implementation of strategies for social protection interventions. We report the quantitative assessment of contact patterns in a village in rural Malawi, based on proximity sensors technology that allows for high-resolution measurements of social contacts. Our results revealed that the community structure of the village was highly correlated with the household membership of the individuals, thus confirming the importance of the family ties within the village. Social contacts within households occurred mainly between adults and children, and adults and adolescents and most of the inter-household social relationships occurred among adults and among adolescents. At the individual level, age and gender social assortment were observed in the inter-household network, and age disassortativity was instead observed in intra-household networks. Moreover, we obtained a clear trend of the daily contact activity of the village. Family members congregated in the early morning, during lunch time and dinner time. In contrast, inter-household contact activity displayed a growth from the morning, reaching a maximum in the afternoon.
The proximity sensors technology used in this study provided high resolution temporal data characterized by timescales comparable with those intrinsic to social dynamics and it thus allowed to have access to the level of information needed to understand the social context of the village.
Capacitive proximity sensors (CPSs) have recently been a focus of increased attention because of their widespread applications, simplicity of design, low cost, and low power consumption. This mini ...review article provides a comprehensive overview of various applications of CPSs, as well as current advancements in CPS construction approaches. We begin by outlining the major technologies utilized in proximity sensing, highlighting their characteristics and applications, and discussing their advantages and disadvantages, with a heavy emphasis on capacitive sensors. Evaluating various nanocomposites for proximity sensing and corresponding detecting approaches ranging from physical to chemical detection are emphasized. The matrix and active ingredients used in such sensors, as well as the measured ranges, will also be discussed. A good understanding of CPSs is not only essential for resolving issues, but is also one of the primary forces propelling CPS technology ahead. We aim to examine the impediments and possible solutions to the development of CPSs. Furthermore, we illustrate how nanocomposite fusion may be used to improve the detection range and accuracy of a CPS while also broadening the application scenarios. Finally, the impact of conductance on sensor performance and other variables that impact the sensitivity distribution of CPSs are presented.
Design And Fabrication Of Centre Line Marker R, Jeremiah; D, Prabhakaran; V.M, Jothi Prakash ...
International journal of engineering and advanced technology,
11/2019, Letnik:
8, Številka:
6s3
Journal Article
Odprti dostop
We have pleasure in introducing our new project “DESIGN AND FABRICATION OF CENTER LINE MARKER”, it is a genuine project which is fully equipped and designed to find out the center point or mark a ...center line in beam or rod in an industry of mass production. This forms an integral equipment of best quality. This product underwent vigorous tests and it’s precise. Center line marker uses the “PROPERTY OF ISOSCELES TRIANGLE”. The “CENTER LINE MARKER” can be used to mark center points and lines using pencils and also dot punch can be used to points for drilling and other purposes. This is very use full in mass production and saves much time. The precision and accuracy of the device will help to manufacture quality products with shorter lead time.
The human body is punctuated with wide array of sensory systems that provide a high evolutionary advantage by facilitating formation of a detailed picture of the immediate surroundings. The sensors ...range across a wide spectrum, acquiring input from noncontact audiovisual means to contact‐based input via touch and taste. The ambit of sensing can be extended further by imparting the body with increased noncontact sensing capability through the phenomenon of electrostatics. Here, a graphene‐based tattoo sensor is presented for proximity sensing, employing the principle of electrostatic gating. The sensor shows a remarkable change in resistance upon exposure to objects surrounded with static charge on them. Compared to prior work in this field, the sensor demonstrates the highest recorded proximity detection range of 20 cm. It is ultrathin, highly skin conformal, and comes with a facile transfer process such that it can be tattooed on the human skin, unlike other graphene‐based proximity sensors reported before. Present work details the operation of wearable proximity sensor while exploring the effect of mounting body on the working mechanism. A possible role of the sensor as an alerting system against unwarranted contact with objects in public places especially during the current COVID‐19 pandemic is also explored.
A reduced graphene oxide (rGO)‐based wearable proximity sensor that works on the principle of electrostatic gating is presented. The sensor shows a remarkable change in resistance upon exposure to objects surrounded with static charge on them with detection range of up to 20 cm. Present work details the operation of proximity sensor while exploring the effect of substrate or mounting body on the sensing mechanism.
Silk, a pyroprotein with its unique micro-structural features comprises of soft amorphous Image 1 regions containing compact Image 2-sheet crystals resulting in its potent characteristics. Annealing ...in inert atmosphere causes carbonization followed by graphitization of these stable Image 2-sheet-rich silk fibroins (SFs). Here we carry out systematic studies of annealed silk fibroin (Bombyx mori) in the temperature range of 200-1200°C by various analytical techniques. Herein the structural changes in SFs at different annealing temperature have been discussed using Raman, FTIR, XPS, XAES, SEM, XRD characterization techniques. Notably XPS and XAES studies were executed to examine the influence of sp2/sp3 ratio and the presence of hetero-atom on D-parameter value in silk Image 2-sheet material on gradual increase in annealing temperature. The mechanical properties of SFs were measured using UTM. The application of carbonized silk fibroins (CSF) as a proximity sensor is also investigated and proposed as a probable active material.
Magneto-inertial measurement units (MIMU) are a suitable solution to assess human motor performance both indoors and outdoors. However, relevant quantities such as step width and base of support, ...which play an important role in gait stability, cannot be directly measured using MIMU alone. To overcome this limitation, we developed a wearable platform specifically designed for human movement analysis applications, which integrates a MIMU and an Infrared Time-of-Flight proximity sensor (IR-ToF), allowing for the estimate of inter-object distance. We proposed a thorough testing protocol for evaluating the IR-ToF sensor performances under experimental conditions resembling those encountered during gait. In particular, we tested the sensor performance for different (i) target colors; (ii) sensor-target distances (up to 200 mm) and (iii) sensor-target angles of incidence (AoI) (up to 60 ∘ ). Both static and dynamic conditions were analyzed. A pendulum, simulating the oscillation of a human leg, was used to generate highly repeatable oscillations with a maximum angular velocity of 6 rad/s. Results showed that the IR-ToF proximity sensor was not sensitive to variations of both distance and target color (except for black). Conversely, a relationship between error magnitude and AoI values was found. For AoI equal to 0 ∘ , the IR-ToF sensor performed equally well both in static and dynamic acquisitions with a distance mean absolute error <1.5 mm. Errors increased up to 3.6 mm (static) and 11.9 mm (dynamic) for AoI equal to ± 30 ∘ , and up to 7.8 mm (static) and 25.6 mm (dynamic) for AoI equal to ± 60 ∘ . In addition, the wearable platform was used during a preliminary experiment for the estimation of the inter-foot distance on a single healthy subject while walking. In conclusion, the combination of magneto-inertial unit and IR-ToF technology represents a valuable alternative solution in terms of accuracy, sampling frequency, dimension and power consumption, compared to existing technologies.
The interrupted-sampling repeater jamming (ISRJ) can cause false targets to the radio-frequency proximity sensors (RFPSs), resulting in a serious decline in the target detection capability of the ...RFPS. This article proposes a recognition method for RFPSs to identify the false targets caused by ISRJ. The proposed method is realized by assigning a unique identity (ID) to each RFPS, and each ID is a periodically and chaotically encrypted in every pulse period. The processing technique of the received signal is divided into ranging and ID decryption. In the ranging part, a high-resolution range profile (HRRP) can be obtained by performing pulse compression with the binary chaotic sequences. To suppress the noise, the singular value decomposition (SVD) is applied in the preprocessing. Regarding ID decryption, targets and ISRJ can be recognized through the encryption and decryption processes, which are controlled by random keys. An adaptability analysis conducted in terms of the peak-to-side lobe ratio (PSLR) and bit error rate (BER) indicates that the proposed method performs well within a 70-kHz Doppler shift. A simulation and experimental results show that the proposed method achieves extremely stable target and ISRJ recognition accuracies at different signal-to-noise ratios （SNRs） and jamming-to-signal ratios (JSRs).
Over the past several decades, naturally occurring and man-made mass casualty incidents (MCIs) have increased in frequency and number worldwide. To test the impact of such events on medical ...resources, simulations can provide a safe, controlled setting while replicating the chaotic environment typical of an actual disaster. A standardized method to collect and analyze data from mass casualty exercises is needed to assess preparedness and performance of the health care staff involved.
In this study, we aimed to assess the feasibility of using wearable proximity sensors to measure proximity events during an MCI simulation. In the first instance, our objective was to demonstrate how proximity sensors can collect spatial and temporal information about the interactions between medical staff and patients during an MCI exercise in a quasi-autonomous way. In addition, we assessed how the deployment of this technology could help improve future simulations by analyzing the flow of patients in the hospital.
Data were obtained and collected through the deployment of wearable proximity sensors during an MCI functional exercise. The scenario included 2 areas: the accident site and the Advanced Medical Post, and the exercise lasted 3 hours. A total of 238 participants were involved in the exercise and classified in categories according to their role: 14 medical doctors, 16 nurses, 134 victims, 47 Emergency Medical Services staff members, and 27 health care assistants and other hospital support staff. Each victim was assigned a score related to the severity of his/her injury. Each participant wore a proximity sensor, and in addition, 30 fixed devices were placed in the field hospital.
The contact networks show a heterogeneous distribution of the cumulative time spent in proximity by the participants. We obtained contact matrices based on the cumulative time spent in proximity between the victims and rescuers. Our results showed that the time spent in proximity by the health care teams with the victims is related to the severity of the patient's injury. The analysis of patients' flow showed that the presence of patients in the rooms of the hospital is consistent with the triage code and diagnosis, and no obvious bottlenecks were found.
Our study shows the feasibility of the use of wearable sensors for tracking close contacts among individuals during an MCI simulation. It represents, to our knowledge, the first example of unsupervised data collection-ie, without the need for the involvement of observers, which could compromise the realism of the exercise-of face-to-face contacts during an MCI exercise. Moreover, by permitting detailed data collection about the simulation, such as data related to the flow of patients in the hospital, such deployment provides highly relevant input for the improvement of MCI resource allocation and management.
In recent years human–machine interaction has become increasingly important in industrial applications and daily life. Proximity sensors are expected to become an important part of such systems. The ...mechanisms of these sensors are usually based on ultrasound, capacitance, triboelectric effect, optical imaging or semiconducting devices. The fabrication and sensing performance of solution‐based organic transistor proximity sensors is reported. To enhance electrical performance, nanogroove templates are introduced to guide the oriented growth of organic semiconducting layer. The templates are realized by friction‐transferring polytetrafluoroethylene thin layers onto SiO2/Si substrates. An extended gate structure for proximity sensing is designed, in which one end of a silver wire is electrically connected with the gate of the transistor and the other end serves as the sensing end. Proximity sensing is characterized by bringing various charged stimuli close to the sensor and recording the resulting change in drain current. The sensor showed good repeatability during the approach and withdrawal of a stimulus. A maximum current response of 2.2 μA between distances of 3 mm and 53 mm and distance sensitivity of 2.5 nA mm‐1 at a distance of 13 mm are obtained when a charged polytetrafluoroethylene rod is moved up and down above the sensing end.
High‐performance proximity sensors are realized via solution‐based fabrication of organic field‐effect transistors. Nanogrooved polytetrafluoroethylene templates are introduced to induce anisotropic crystallization and thus improve electrical performance. An extended gate configuration is designed for proximity sensing. Such sensors show good electrical response to approach and withdrawal of various charged objects with large current response and distance sensitivity.
Unlike electromagnetic radiation such as radio waves, infrared‐visible‐ultraviolet, and X‐rays, static or quasi‐static electric fields are rarely utilized for visualization in people's lives and ...industries. The difficulty in measuring quasi‐static electric fields is mainly due to low‐energy photons and the lack of integrable devices with high sensitivity to detect them. Here, a novel quasi‐static electric field sensor based on a floating extended gate organic field‐effect transistor is shown, which is highly sensitive, integrable as an array, ultra‐flexible, highly expandable, and digitally printable. The sensor has a thickness of ≈2 µm and can detect the proximity to human hands with low static electricity at a distance of tens of centimeters. The sensor can provide a new vision of electric charges, proximity sensing capability, and, in the future, a noncontact method for measuring biological activities such as brain waves.
Here, a novel quasi‐static electric field sensor based on floating extended gate organic field‐effect transistors is shown, which is highly sensitive, integrable as an array, ultra‐flexible, highly expandable, and digitally printable. The sensor has a thickness of ≈2 µm and can detect the proximity to human hands with low static electricity at a distance of tens of centimeters.
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