Residential access control system using QR code and the IoT

This paper presents a residential access control system (RACs) using QR codes and the internet of things (IoT) to improve security and help house owners. The contribution of this paper is that it proposes two mechanisms in the authentication phase and the verification phase, respectively, to enhance residential access control. The main idea is using cryptography between smartphones and access control devices. The cryptography compares secret codes on the key server via the internet. The RACs can notify a user of the residential access status through the LINE application and show the statuses of devices through the network platform for the internet of everything (NETPIE) in real-time. We compare this system’s performance with that of the current access control methods in terms of security and access speed. The results show that this system has more security and has an access speed of 5.63 seconds. Moreover, this system is safer and more flexible than the comparative methods and suitable for contactless authentication

A Survey of Energy Harvesting Sources for IoT Device

Environmental Energy is an alternative energy for wireless devices. A Survey of Energy Harvesting Sources for IoT Device is proposed. This paper identifies the sources of energy harvesting, methods and power density of each technique. Many reassert have carried to extract energy from environment. The IoT and M2M are connected through internet or local area network and these devices come with batteries. The maintenance and charging of batteries becomes tedious due to thousands of device are connected. The concept of Energy harvesting gives the solution for powering IoT, M2M, Wireless nodes etc. The process of extracting energy from the surrounding environment is termed as energy harvesting and derived from windmill and water wheel, thermal, mechanical, solar

Modeling the human knee joint using the Proper Generalized Decomposition

Nowadays, human joints specifically movable are active research topics. The lack of effective replacements and the inefficient natural healing of these joints hinders any athlete from pursuing his career if injured in his joints. Therefore, researchers are testing innovative soft materials and biphasic materi- als as replacements of human joints. However, the lack of effective mechanical modeling is slowing the development of new replacements. In this work, we tackle the mechanical modeling of the synovial joint in a human knee. The tibiofemoral joint is modelled during impact. This joint is basically made of a cartilage, a meniscus (both a biphasic material) and the synovial fluid. The modeling is performed using Brinkman equation. However, the rich physics in- volved in the thickness direction requires a large number of degrees of freedom in the mesh to represent the physical phenomenon taking place in a knee joint. Thus, the use of model order reduction techniques appears to be an appealing approach in this situation. In fact, the proper generalized decomposition re- duced the number of degrees of freedom by using domain decomposition. The result of this work shows the pressure and fluid flow in the synovial joint under impact. A post treatment of the solution estimates the force held by each of the fluid and solid components of the cartilage joint. This model could be used to the human knee to estimate its components’ velocities and pressure fields while performing an activity

Computational vamedecum of the coupled mechanical/thermal behavior of composite materials during ultrasonic welding

Aiming faster and more reliable end products, the composite material in- dustry is nowadays an active research topic. Innovative composite forming processes are actively designed and tested. For example, ultrasonic welding of composite thermoplastic materials is being investigated, since it shows many advantages over classical methods. In fact, energy directors allow a preferential heating of the manufactured part through the propagation of mechanical waves in a composite laminate, without including any foreign material in the welded region. However, ultrasonic welding of composite materi- als is not mastered yet because of the coupled and complex behavior of such materials. Thus, simulation of ultrasonic heating becomes compulsory for understanding the complex multi-physics coupled problem. In this work, we propose to model the ultrasonic welding process using a dynamic vis- coelastic model in the frequency domain. Later on, this model is coupled to the transient heat equation, giving the temperature field as well as the heat flux in the simulated part. However, the result depends on the chosen experimental and material parameters such as the thickness of the part, its viscosity, its modulus of elasticity, the imposed frequency and displacement... Which makes the optimization of the process a tricky issue requiring a new set of solutions of the problem for each choice of the process parameters. Using the proper generalized decomposition (PGD), along with a coupled viscoelas- tic/thermal model, where all the parameters mentioned above are included as extra co- ordinates of the problem, appears to be a suitable solution for the optimization problem. Moreover, the PGD multidimensional solution considering all the process parameters as extra coordinates is obtained within a realistic timeframe. In fact, by using the PGD, we alleviate the curse of dimensionality since the PGD performs a separation of variables which reduces the problem dimensionality [1]. The result is therefore a computational vademecum that can be used to explore in real time the solution of the problem for any choice of the process parameters, speeding up its optimization [2]

A Shortest Data Window Algorithm for Detecting the Power Factor in presence of non-sinusoidal load current

During recent years, nonlinear power electronic equipments introduce harmonic pollution on electric power systems. It makes the traditional power factor meter can not act accurately when it monitors unbalanced and harmonic loads. In this paper, a new algorithm for detecting the power factor in presence of non-sinusoidal load current is proposed. The proposed algorithm detects the true power factor exactly. By uses only two successive sampled data points of the voltage and the current for each displacement power factor value calculation and two sampled data points for each distortion power factor value calculation, the total/true power factor becomes easy to measure using these values directly. The proposed detector implemented using microcontroller as a main part and has been tested for single phase power system. The test results show that it can measure the true power factor of the loads quickly and accurately

Sistema eletrônico integrado para controle de acesso - um estudo de caso para a Universidade Federal de Santa Catarina

TCC(graduação) - Universidade Federal de Santa Catarina. Campus Araranguá. Engenharia da Computação.O controle de acesso, tipicamente, é implementado por fechaduras com chaves convencionais, sistema este criado há séculos. A utilização deste artifício em ambientes onde muitas pessoas necessitam ter acesso, pode causar transtornos, como o extravio das cópias das chaves e o agrupamento de muitas chaves para usuários que têm acesso à múltiplas salas. Para amenizar estes problemas, existem fechaduras eletrônicas disponíveis no mercado. Contudo, a maioria dos modelos são do tipo standalone, ou seja, sem conexão com outras fechaduras ou com um computador administrador, necessitando assim serem programadas individualmente, o quê não é uma tarefa desejada, especialmente em ambientes com várias salas e com várias fechaduras. Outro fator limitante às opções atuais no mercado é o preço elevado. Este trabalho têm o intuito de desenvolver uma solução para controle de acesso de baixo custo, utilizando identificação por rádio frequência (RFID) e que permita a atualização dos dados de acesso via rede wireless. O foco do trabalho é resolver o problema da Universidade Federal de Santa Catarina no controle de seus laboratórios e salas. Entretanto, o sistema pode ser adaptado para a utilização em aplicações de automação residencial e predial, sendo um produto potencialmente comercial.Access control typically is implemented by door locks with traditional keys, a system that was created centuries ago. The use of this system in environments where many people need access may cause inconveniences, like key loss and the gathering of too many keys by users who have access to multiple rooms. To settle these problems, there are electronic door locks available on the market. However, most of the models are built in a standalone way, in other words, are built without connection with other locks or an administrator computer, thus needed to be individually programmed, which is not a desired task, especially in environments with several rooms and several locks. Another limiting factor to the current options in the market is the high price. This undergraduate thesis aims to develop a low cost access control solution, using radio frequency identification (RFID), that allows the update of access data through wireless network. The focus here is to solve the University of Santa Catarina control access problems in its rooms and laboratories. However, the system can be adapted to be used in applications like residential and building automation, being a potentially commercial product