Today, more than 80% of the produced energy in the world comes from fossil fuels. Therefore, the search of new methods is considered in order to use of new source energy. Sea is one of the most important sources of energy. The waves are the main sources of energy that by using technology and modern equipment, it can be converted into needed energy for different purposes. In this paper, according to this fact, the modeling of device is considered that can be used to model the energy of ocean waves into electrical energy for different goals. This device has a cylindrical buoy which uses heave motion in order to produce energy. The simulation of mathematic equations of the device has been done in Matlab Simulink and the results of modeling and analysis, including displacement, velocity, force and power has been considered.

Environmental concerns have increased the interest to renewable energy technologies. Theoretical Studies on the point absorber theory of ocean wave energy started about four decades ago and less than two decades, the studies are focused on the designing of the point absorber wave energy converters.Today, researches are in the optimization and modification of existing methods, the innovation of new approaches and the forecast of the efficiency of the point absorber converters.In this paper, the effects of tension leg system on the hydrodynamic performance of a two-body floating-point absorber wave energy system are studied. In modeling, the two-body converter consists of: the immersed body and buoy, which are connected through a linear mass–spring system to represent the power take-off (PTO) mechanism. The hydrodynamic analysis is performed in the time domain. The results show the positive effects of tension leg anchor on the increase of relative motion between the immersed body and buoy and the increase of converter efficiency up to 6.2 percent.

This paper presents, assesses, and optimizes a point absorber wave energy converter (WEC) through numerical modeling, simulation, and analysis in both frequency and time domain. Wave energy conversion is a technology especially suited for assisting in power generation in the offshore oil and gas platforms. A linear frequency domain model is created to predict the behavior of the heaving point absorber WEC system. The hydrodynamic parameters are obtained with AQWA, a software package based on boundary element methods. A linear external damping coefficient is applied to enable power absorption, and an external spring force is introduced to tune the point absorber to the incoming wave conditions.The external damping coefficient and external spring forces are the control parameters, which need to be optimized to maximize the power absorption. Two buoy shapes are tested and a variety of diameters and drafts are compared.Optimal shape, draft, and diameter of the model are then determined to maximize its power absorption capacity.Based on the results generated from the frequency domain analysis, a time domain analysis was also conducted to derive the responses of the WEC in the hydrodynamic time response domain. The time domain analysis results allowed us to estimate the power output of this WEC system.

In this paper, a new high step-up current-fed LLC resonant DC-DC converter with a center-tapped transformer is proposed. By selecting the switching frequency to be lower than, but near to, the series resonant frequency of the LLC resonant tank, soft-switching operation of all semiconductors, i.e., zero voltage switching (ZVS) turn-on of power MOSFETs and zero current switching (ZCS) turn-off of diodes is achieved. This leads to lower electromagnetic interference (EMI) and lower switching losses and improves the converter efficiency. An interleaved structure is used at the primary side. Thus, input current ripple is smaller, and its frequency is twice the switching frequency. Consequently, a smaller input filter is necessary in practice. The converter with 1.2 kW output power and 760 V regulated output voltage with 80-200 V input voltage variations is simulated. The output voltage is regulated by using asymmetric pulse width modulation (APWM) at 200 kHz switching frequency. Finally, a 700-W prototype has been implemented and experimental results are also presented to verify the simulation results.

Solar-powered generator is one of the critical parts in designing and manufacturing of the satellites. Achieving a high degree of reliability and maximum absorption in the Solar-powered generator are two key factors considered by designers. In this paper, designing and manufacturing different components of a charging part of a nano-satellite have been evaluated by considering environmental constraints. Simplicity and high degree of reliability are the main aspects of the proposed method that lead to maximum amount of power absorption. The innovation of this paper is detecting the optimal operating point of the solar panel based on the measurement of the solar cell temperature. In addition, an I2C communication protocol has been implemented between PMU and C&DH in order to simultaneously monitor of voltage and current of various points and receiving controlling orders from the stations on earth. After designing and simulating of the controller of the charging part of the satellite, various necessary components for building of each subsystem have been prepared. In the next step, prototype of the charging circuit board was built and tested. According to the test results, necessary modifications were implemented on the final circuit board. Finally, the last version of the PMU circuit board was designed and built. Utilizing the boost synchronous converter, the efficiency of the converter section is improved up to 95%.

Background: Finding a reliable diagnostic method for brucellosis is the most challengeable problem. In this study we determined the optimal diagnostic cut-off point for ELISA test.Methods: We gathered 56 confirmed cases of brucellosis. Furthermore blood samples from 126 controls including 73 healthy controls and 53 without brucellosis febrile patients were collected. In all of the cases and controls ELISA Ig G and ELISA Ig M levels were measured and compared with each other by Box plot graph and the Receiver Operating Characteristic (ROC) curve. The sensitivity and specificity of ELISA Ig G and Ig M were fixed in different cut-off values and Ig G and Ig M levels yielding maximal sensitivity plus specificity were selected for determination of optimal cut-off point.Results: The nineteen patients had positive blood cultures for Brucella melitensis. The standard agglutination test results were 1/160 or more in 54 patients. The Box plot graph indicated a high degree of dispersion for Ig G and Ig M data in patients with brucellosis compared with febrile patients without brucellosis and healthy controls. We observed partial overlap for Ig M data (not for Ig G) between cases and controls. The area under ROC curve for discrimination of cases and healthy controls was more for Ig G than Ig M.Conclusions: The ELISA Ig G is more reliable test than ELISA Ig M in diagnosis of brucellosis. Using cut-off of 10 IU/ml and 50 IU/ml have the most sensitivity (92.9%) and specificity (100%) for ELISA Ig G test, respectively. 

Statistical Shape Models are used to interpret shapes. They include mean and variance of corresponding points of training shapes. One of the most important challenges in building statistical shape models is to establish correct correspondences among landmarks in a training set. In this paper, the non-rigid CPD (Coherent point Drift) method is used to find correct correspondences among points. This method uses both Deterministic Annealing and a non-rigid scheme to register two shapes simultaneously. Then, the statistical shape model is built using a rigid transformation. The proposed method is evaluated using Compactness, Generalization ability and Specificity measures. The built model is compared to models created using the ICP (Iterative Closest point), TPS-RPM (Thin Plate Spline – Robust point Matching) and MDL (Minimum Descreption Length) methods by these metrics. The results show that the proposed method performs like the MDL regarding Specificity measure (0.21±0.06). The Compactness and Generalization ability measures of the proposed method are very similar to those for the MDL method. The run-time of our proposed method is about 68 seconds which is faster than non-rigid TPS-RPM and MDL approaches (390 and 3600 seconds respectively). Our results are superior to the ICP and TPS-RPM algorithms.