LED Signal Research Articles

Possibilities of Skin Autofluorescence Reflecting the Characteristics of Diabetes Mellitus in Childhood

Objective: To measure skin autofluorescence in children and adolescents suffering from type 1 diabetes mellitus and evaluate its relationship with gender, age, experience and chronic complications of the disease. Materials and Methods: The study group included 47 children and adolescents with type 1 diabetes. Autofluorescence of the skin from the inner surface of the shoulder and nail of patients was measured using an original compact spectrofluorimeter based on the STS-VIS OCEAN OPTICS © USA microspectrometer with UVA excitation. Statistical analysis was carried out using StatsoftStatistica 12.0 software. The data is presented as a two-dimensional array. The UV LED signal was averaged and smoothed using the moving average method with a 10 nm window. Then the spectra were renormalized taking into account the found coefficients. The result of applying additional normalization is a decrease in the standard deviation. Results and Discussion: Significant differences were revealed in the skin fluorescence spectra of children of different ages. between age groups (5-7) and (8-12) is most significant in the region of the alpha band of oxyhemoglobin (540 nm) (p <0.005). When using I-normalization, the NADH peak region (p < 0.02) is significant with increasing disease duration. When studying the influence of gender factors on the level of skin autofluorescence, the most significant differences are found in the area of only the isosbestic points of deoxy and oxyhemoglobin 442 nm (p<10-7) and 491 nm (p<10-8). Significant differences in skin autofluorescence at the reference length were also obtained waves in the autofluorescence spectrum of 500 nm correspond to p<10-14, depending on the presence of complications. Conclusion: In Russia, as well as throughout the world, there is an increase in the incidence of type 1 diabetes mellitus. For early diagnosis of changes in carbohydrate metabolism and complications of the disease, a simple, accessible, non-invasive research method is needed. Taking into account the results of our study, when creating non-invasive methods for monitoring the state of carbohydrate metabolism, it is necessary to take into account gender and age characteristics, experience and the presence of complications of type 1 diabetes mellitus.

Assessment of skin autofluorescence in children with diabetes mellitus type

Objective: To measure skin autofluorescence in children and adolescents suffering from type 1 diabetes mellitus and evaluate its relationship with gender, age, experience, and chronic complications of the disease. Materials and methods: The study group included 47 children and adolescents with type 1 diabetes. Autofluorescence of the skin from the inner surface of the shoulder and nail of patients was measured using an original compact spectrofluorimeter based on the STS-VIS OCEAN OPTICS © USA microspectrometer with UVA excitation. Statistical analysis was carried out using StatsoftStatistica 12.0 software. The data is presented as a two-dimensional array. The UV LED signal was averaged and smoothed using the moving average method with a 10 nm window. Then the spectra were renormalized taking into account the found coefficients. The result of applying additional normalization is a decrease in the standard deviation. Results and discussion: Significant differences were revealed in the skin fluorescence spectra of children of different ages. Between age groups (5-7) and (8-12) is most significant in the region of the alpha band of oxyhemoglobin (540 nm) (p < 0.005). When using I-normalization, the NADH peak region (p < 0.02) is significant with increasing disease duration. When studying the influence of gender factors on the level of skin autofluorescence, the most significant differences are found in the area of only the isosbestic points of deoxy and oxyhemoglobin 442 nm (p < 10-7) and 491 nm (p < 10-8). Significant differences in skin autofluorescence at the reference length were also obtained waves in the autofluorescence spectrum of 500 nm correspond to p < 10-14, depending on the presence of complications. Conclusion: In Russia, as well as throughout the world, there is an increase in the incidence of type 1 diabetes mellitus. For early diagnosis of changes in carbohydrate metabolism and complications of the disease, a simple, accessible, non-invasive research method is needed. Taking into account the results of our study, when creating non-invasive methods for monitoring the state of carbohydrate metabolism, it is necessary to take into account gender and age characteristics, experience, and the presence of complications of type 1 diabetes mellitus.

IoT Based Flood Monitoring and Alarm System

As we all know that Flood is one of the major well known Natural Disasters. When water level suddenly rises in dams, river beds etc. A lot of Destruction happens at surrounding places. It causes a huge amount of loss to our environment and living beings as well. So in these case, it is very important to get emergency alerts of the water level situation in different conditions in the river bed. The purpose of this project is to sense the water level in river beds and check if they are in normal condition. If they reach beyond the limit, then it alerts people through LED signals and buzzer sound. Also it alerts people through IOT alerts when the water level reaches beyond the limit.

Increasing the power and spectral efficiencies of an OFDM-based VLC system through multi-objective optimization.

The nonlinearity induced by light-emitting diodes in visible light communication (VLC) systems presents a challenge to the parametrization of orthogonal frequency division multiplexing (OFDM). The goal of the multi-objective optimization problem presented in this study is to maximize the transmitted power (superimposed LED bias-current and signal amplification) for both conventional and constant envelope (CE) OFDM while also maximizing spectral efficiency. The bit error rate (BER) metric is used to evaluate the optimization using the non-dominated sorting genetic algorithm II. Simulation results show that for a BER of 1×10-3, the signal-to-noise ratio (SNR) required decreases with the guard band due to intermodulation distortions. In contrast to SNR values of approximately 13 and 25dB achieved by traditional OFDM-based systems, the VLC system with CE signals achieves a guard band of 6% of the signal bandwidth with required SNR values of approximately 10.8 and 24dB for 4-quadrature amplitude modulation (QAM) and 16-QAM modulation orders, respectively.

Analysis and Development of A Self-Dimming Module for Road Traffic Signals

Nowadays, we often see more and more of the various types of lights in urban areas, especially in road areas, either regarding the use of traffic lights or streetlights that serve as guides and signals to maintain road safety. Typically, the lamps use LED-based lamps as they can increase the rate of high savings. This LED conceptual light helps reduce energy wastage by using less power and reducing the consumption of heat and is suitable for day-to-day operation. The addition of ordinary LEDs to self-dimming systems based on the intensity of light around is more likely to increase the savings rate and is more environment-friendly. The scope of this research includes analytics data from the use of standard traffic lights and LED signal lights that are self-concept in dimmer systems. This research uses the IoT concept that is applied to the traffic system and uses solar energy which is indeed renewable natural energy and can affect the green earth concept to the traffic control system on the road.

Energy effective Technologies on Transport: Safety of Appliance of LED Railway Signals

For about 50 years the LED technology of visual information transfer is world-known, in spite of it, there is a row of unsolved questions of implementation of LED railway signals till present. This article is devoted to the analysis of topical issues on introduction of LED signals on railway transport, in particular: modes of operations of railway signals, influence of the atmospheric phenomena on the transmission of signal, unconcern of new technology as compared to glow lamps etc. There have been separately analysed the possible failures of LED matrix elements and the choice of the most rational structure of matrix has been grounded from the point of view of the railway signal functioning safety.

What Does That Car Mean? The Influence of Vehicle Motion and Symbolic Patterns of LED Signals on Pedestrians’ Interpretation of a Vehicle’s Intent

One critical issue of autonomous vehicles is how to communicate the intention to pedestrians. In this study, the impact of two factors (vehicle motion and LED lighting signal type) on participants’ interpretation of LED signals were investigated. A total of 80 participants completed the study online. We found that motion affects participants’ interpretation, but depending on the LED pattern; participants were also able to understand the vehicle’s intention with the attention capturing pattern (flashing squares). In addition, some creative interpretations were reported suggesting an opportunity to redefine the meaning of light patterns. Implications of these findings and next steps were discussed.澳

Response timing of budgerigars in a turn-taking task under operant conditioning

Turn-taking is universally seen in humans during the completion of various tasks. Turn-taking is also reported in non-human animals in the wild; however, in these cases turn-taking is displayed during innate and stereotypic behaviors, so it may differ from turn-taking seen in humans. In the present study, budgerigars were trained to take turns between two individuals under operant control. Two cages were placed adjacent to one another and each cage contained one bird of a pair. Each bird pecked a response key in turn to produce a peck sequence for a reward. All pairs learned this task and one bird of the pairs often pecked the LED slightly before the signal onset, indicating that the peck was not a mere reaction to the LED signal. Furthermore, the preference examination suggested that a male bird pecked more rapidly while paired with a bird he preferred. Thus, they created a “pseudo” turn-taking sequence similar to humans. In addition, results from the male bird suggests a possibility that peck timing may be influenced by their preference. This study did not show whether birds collectively worked for a goal; however, the partner dependent behavior may be elements to form “true” turn-taking behavior.

Impact of Dynamic LED Non-Linearity on DCO-OFDM Optical Wireless Communication

DC-Offset Orthogonal Frequency Division Multiplexing (DCO-OFDM) is a popular modulation method for Optical Wireless Communication (OWC) as it can assign specific power levels and constellations to different subcarrier frequencies across the low-pass response of the LED. However, LEDs exhibit dynamic non-linearities to which OFDM is very sensitive. As LED signals are subject to non-linear memory effects in photon generation, different OFDM subcarriers experience different amounts of distortion. This letter translates the LED behavior into a communication channel model for OFDM modulation. It gives an experimentally verified expression for the Signal-to-Distortion Ratio (SDR) as it varies per subcarrier in OFDM systems.

Compensating Dynamic Nonlinearities in LED Photon Emission to Enhance Optical Wireless Communication

LEDs can be modulated to support wireless optical data communication. However, particularly LEDs optimized for illumination act as a non-linear low-pass communication channel. In this paper, we translate the non-linear differential equations for the hole-electron recombination and photon emissions, into a discrete-time model with delay taps and non-linear coefficients. This LED model can be inverted, to actively eliminate or mitigate the non-linear dynamic LED distortion. We propose a further simplification of the compensation circuit that allows us to use a relatively simple structure with only a couple of parameters. We experimentally characterize and measure signals communicated via commercially available illumination LEDs that are also used for LiFi communication. In an Intensity Modulation Direct Detection (IM/DD) system employing Pulse Amplitude Modulation (PAM), we show that the proposed equalizer can effectively widen the measured eye diagram, thereby reduce the error rate or can allow a larger constellation. For Orthogonal Frequency Division Multiplexing (OFDM), the reduction in distortion allows at least a 50% increase in bit rate, even on measured noisy channels. This confirms the suitability of the LED model on which our non-linear equalizer is based. We show how non-linear time-constants can be estimated from electrical measurements on the LED signal. With the proposed parameter estimation, the equalizer converges to appropriate compensation settings, in Minimum Mean Square Error (MMSE) sense.

Smart Navigation of Vehicles using RFID in Remote Environments

Vehicles are one of the most important sources of transport and the number of vehicular deaths occurring in hill stations is increasing day by day. The main focus of this work is finding a feasible initiative using RFID technology for effective navigation with maximal safety and minimal risk in exceptional road conditions, which may be due to weather, climatic conditions or geographical locations. The hairpin bends and steep turns in hill station roads is a major cause of accidents. To prevent any untoward incidents, we propose to use the RFID (radio frequency) tags and detectors to alert the driver of the incoming turn or bend some 100 meters before the turning point. The RF tag will alert the driver in the form of an LED signal. Acceleration which is in a fixed coordinate system makes sure any changes in the angle are indicated by the accelerometer sensor connected to the Arduino. An LCD is connected to the Arduino which displays the sea level, left and right turn as text with the turning angle. Also, the buzzer attached to the Arduino gives a sound alert. In this paper, we will focus primarily on avoiding accidents and road crashes in hill stations and remote environments by making use of RFID technology

Performance, Monitoring and Controlling of Smart Energy Meter with IOT and Arduino UNO

The main purpose of the plan is to build up an IOT base electrical energy meter interpretation show for units devoted and charge there upon over the internet. A smart energy meter whose blinking LED signal is interfaced to microcontroller during LDR the blinking LED flash 3200 times for 1 part the LDR sensor provide an interrupt every instance the meter LED flash to the programmed microcontroller, micro controller take this considerate and display the it on an LCD accordingly interfaced to the microcontroller. the learn of the energy meter is also sent to Ethernet guard module individual fed from the micro controller using level shifter IC and RS 232 link which pass on data in a straight line to a devoted web page for show anywhere in the planet. The power provide consists of a step down transformer 230/12V which decreases the voltage to 12V AC. This is changed to DC using a bridge rectifier and it is then regulated to 5V by means of a voltage regulator which is requisite for the action of the microcontroller and additional mechanism.

Charge-to-heat transducers exploiting the Neganov-Trofimov-Luke effect for light detection in rare-event searches

In this work we present how to fabricate large-area (15 cm2), ultra-low threshold germanium bolometric photo-detectors and how to operate them to detect few (optical) photons. These detectors work at temperatures as low as few tens of mK and exploit the Neganov-Trofimov-Luke (NTL) effect. They are operated as charge-to-heat transducers: the heat signal is linearly increased by simply changing a voltage bias applied to special metal electrodes, fabricated onto the germanium absorber, and read by a (NTD-Ge) thermal sensor. We fabricated a batch of five prototypes and ran them in different facilities with dilution refrigerators. We carefully studied how impinging spurious infrared radiation impacts the detector performances, by shining infrared photons via optical-fiber-guided LED signals, in a controlled manner, into the bolometers. We hence demonstrated how the radiation-tightness of the test environment tremendously enhances the detector performances, allowing to set electrode voltage bias up to 90 volts without any leakage current and signal-to-noise gain as large as a factor 12 (for visible photons). As consequence, for the first time we could operate large-area NTD-Ge-sensor-equipped NTL bolometric photo-detectors capable to reach sub 10-eV baseline noise (RMS). Such detectors open new frontiers for rare-event search experiments based on low light yield Ge-NTD equipped scintillating bolometers, such the CUPID neutrinoless double-beta decay experiment.

Towards the Design and Development of an Embedded System for Detecting Silent Aspiration

This design describes a mobile prototype for detecting silent aspiration in children, people with neurological disorders using various biosignals such the measurement of the respiratory rate, pulse rate and oxygen saturation. Pulmonary Aspiration is when food or other particles enter from the pharynx into the larynx, often leading to pneumonia or rarely, fatal asphyxiation. In some patients with dysphagia, silent aspiration occurs, where the aspirating patient does not show any sign such as coughing at all. It is common in stroke patients and infants with neurological disorders such as down syndrome and cerebral palsy. The prototype provides signals that can be displayed with NI-myDAQ (LabVIEW). The signals are acquired with the help of a prototype respiratory belt tied around the chest containing a piezo sensor that senses pressure sending electric signals that will help analyse the breath pattern of the patient. The prototype is fitted with a sensor for measuring the pulse rate of the patient through photoplethysmography. They are all connected to a primary Arduino Nano Microcontroller based on the ATmega328P. Housed in a portable container which also contains an LCD display that can display the real time data. The device has an alert system by means of an LED and a Buzzer, the LED signals whenever there’s a pressure and the alarm sounds when there is a gap in the respiratory movement of the patient due to aspiration.

Indoor mobile robot self-localization based on a low-cost light system with a novel emitter arrangement

This paper proposes a low-cost infrared (IR) LED system with a novel arrangement that enables the self-localization of an indoor mobile robot. The proposed system uses only low-cost IR LED emitters installed on the ceiling of a building and low-cost IR receivers, each equipped with a photodiode, located on top of the mobile robot for detection. The IR LEDs, which are driven by an on-off keying modulator with various frequencies, are used as active landmarks. The mobile robot localizes itself based on the IR LED signals it receives. Although it would be desirable to assign a unique ID to each emitter, this would be difficult to realize because of the limited number of available frequencies and the production cost resulting from the use of independent microcontrollers. Therefore, we designed a novel landmark configuration consisting of an IR LED array with unique ID-encoding capabilities based on a combination of different frequencies and the repeated use of each ID encoding LED to address the problem of limited frequencies. The novel landmark arrangement reduces the costs associated with production, ID encoding, and computation. A Monte-Carlo localization method with a belief function is utilized to estimate the position and orientation of the mobile robot based on the decoded ID information and received signal strength. The proposed system was tested in a real environment and the experimental results confirmed the validity and accuracy of the system and method.

The composition of visual texture design on surface for color vision deficiency (CVD)

Color serves as a nonlinguistic code that gives us instant information about the world around us. Based on color vision and visual perception theories, this study aimed to create a set of texture composition principles that not only supports a person with Color Vision Deficiency (CVD) to distinguish colors, but also maintains the visibility and aesthetic of the target. The study defined the texture background as red RGB(255, 0, 0). After the operational definition, a focus on the independent variable of texture color, elements size, and distance was possible. Second, the constant stimuli method was employed to measure the visible texture compositions by CVDs and Normal Color Vision (NCV) people. Finally, NCVs were asked to subjectively evaluate the influence level. Depending on the purpose and position of the application, designers can decide which compositions benefit viewers. For being detected immediately by CVDs, the proper parameters on a red background are the texture elements with RGB(234, 0, 21) color, dimension 2.5′, and clearance 2.5'. For website designs or commercial advertisements, designers can choose a smaller dimension 1.67′ and clearance 5′, so CVDs can easily read the information without a lack of aesthetics for NCVs. The parameters might be a little different if the image is displayed on paper or through LED signals. For this reason, future studies could take material and environment into consideration, and conclude a series of texture composition principles to support Color Vision Deficiency.

Goalkeeper’s position for defending short range shots

The purpose of the study was to analyze and quantify the ability of the goalkeeper while defending shots from left and right sides of penalty area or the goal area, which frequently occurs in an actual game situation. In other words, the study aimed at verifying the reaction ability of the goalkeeper to defend goals in two different defense positions across a 3 m width area without performing dives. Eleven male goalkeepers from a university soccer league participated in the study. The goalkeepers were assigned to react to a specific target point, i.e. high, middle, low, left and right in response to the LED signal positioned at the front. Three-dimensional motion analysis system was used to perform kinematical analysis through which variables such as the approach time of reaching specific target points and the movement used to cover the defensive area were observed. In results, no significant differences were observed in approach time of the hand to the target point in both defense positions, i.e. Type-A (defense posture of positioning the hand at knee height) and Type-B (defense posture of positioning the hand at waist height). But Type-B defense position average velocity was observed faster than Type-A for blocking shots of low-middle heights. Hence, the results obtained from the study showed a possibility that being prepared in Type-A defense position will be more accurate and stable. Moreover, goalkeepers were able to occupy wider defense range in Type-A defense position than Type-B within the time period of 0.7 ∼ 0.8 s after triggering of the LED signal. In conclusion, the results obtained from the study pointed out that Type-A defense position can be much more effective in soccer for blocking shots from the left and right sides of the penalty area. The defense posture of positioning the hand at low height is considered more effective when defending a ball shot from areas near the penalty area than the high hand position. It was also confirmed that the available defense area can be defended widely and effectively by moving the center of the body. Further studies need to be performed to consider the cognitive perspective by applying various methods.

Visible Light Communication Module: An Open Source Extension to the ns3 Network Simulator With Real System Validation

The emergence of new physical media such as optical wireless and the ability to aggregate these new media with legacy networks motivate the study of heterogeneous network performance, especially with respect to the design of protocols to best exploit the characteristics of each medium. We consider visible light communications (VLC), which is expected to co-exist with legacy and future radio frequency (RF) media. While most of the research on VLC has been done on optimizing the physical medium, research on higher network layers is only beginning to gain attention, requiring new analyses and tools for performance analysis. To meet this need, we have developed a new ns3-based VLC module that can be used to study VLC-RF heterogeneous networks via simulation. The proposed ns3 module has been developed based on existing models for intensity modulated LED signals operating as lighting units transmitting to optical receivers at indoor scales (meters). These models and the corresponding simulation model are validated using a test bed implemented with a software-defined radio system, photo detector, phosphor-converted “white” LEDs, and under PSK and QAM modulation. Two scenarios are used in the validation of the VLC module: 1) using a receiver placed normal to the transmitter with varying range; and 2) using a receiver with a fixed range with varying angle of acceptance. Results indicate good correspondence between the simulated and actual test bed performance. Subsequently, we demonstrate how the VLC module can be used to predict the performance of a hybrid Wi-Fi/VLC network simulated using the ns3 environment with UDP, TCP, and combined network traffic.

Optimizing SNR for indoor visible light communication via selecting communicating LEDs

In this paper, we investigate the layout of LED to optimize SNR by selecting communicating LEDs (C-LEDs) in indoor visible light communication (VLC) system. Due to the inter-symbol interference (ISI) caused by the different arrival time of different optical rays, the SNR for any user is not optimal if a simple layout is adopted. It is interesting to investigate the LEDs layout for achieving optimal SNR in indoor VLC system. For a single user, LED signal is divided into the positive and negative components, they provide the power of desired signal and the power of ISI respectively. We introduce the concept of valid ratio (VR) which refers to the value of positive component over the negative component. Then we propose a VR threshold-based LED selection scheme which chooses C-LEDs by their VRs. For downlink broadcast VLC with multiple users, the SNRs of all users are different in a layout of C-LEDs. It is difficult to find a proper layout of C-LEDs to guarantee the BER of all users. To solve this problem, we propose an evolutionary algorithm (EA)-based scheme to optimize the SNR. The simulation results show that it is an effective method to improve SNR by selecting C-LEDs.

Ultraviolet electroluminescence from Au-ZnO nanowire Schottky type light-emitting diodes

Ultraviolet electroluminescence from Schottky type LED device is demonstrated. The device prototype is based on Schottky junctions formed between Au and the top ends of ZnO nanowire arrays. Rectifying current-voltage characteristics are observed, and three different charge transport mechanisms are discussed in detail. Excitonic electroluminescence at around 380 nm is detected at high forward bias and the linear relationship between intensity and current suggests a LED device performance. The observation of LED signals from the simple Schottky structure provides a potential supplement to the category of ultraviolet LED devices.