Sharif Digital Repository

The title complex has been synthesized and structurally characterized by single-crystal X-ray diffraction. This complex has a dinuclear structure where two copper(II) ions are bridged by two bent alkoxo groups. The citrate acts as a tetradentate ligand coordinating via three carboxylates and an alkoxo groups in which one of three carboxylates is coordinated weakly. The coordination geometry around the Cu(II) is strongly distorted square pyramidal. The distance between the two copper atoms is 2.8386(3)Å. 2007 © The Japan Society for Analytical Chemistry  

Background: Gamma camera count rate saturation and high-rate dead time are the most important problems of quantitative measurement in dosimetric studies. In this study, we aimed to assess an algorithm for correction of the measured counting rates in the entire energy spectrum (327–400 keV) for camera dead-time effects. Methods: In our study, whole body (WB) scan was performed by using a tissue-equivalent phantom, and that the radioactive Iodine (I-131) source with activities of 0.3, 0.6, 1.2, 1.5, 2.07, 2.7, 3.7, and 5.55 GBq was applied. WB scans of the 20% width energy windows were acquired for 420 s. Results: Camera dead-time parameters were obtained from different activities of I-131 in... 

For a moving camera recognizing that it has seen a place before now, is one the most important issues in the 3D reconstruction problems. In these problems, the main goal is to create a three-dimensional model from a sequence of 2D captured images during different times. That part of the scene which is rendered by a camera is often modeled by a frustum. Calculating the amount of intersection of two camera view frustums at different times can help to solve this problem. However, there are two major difficulties. First, calculating the intersection of two frustums, in general, is so complicated. And second, there are some uncertainties in the moving camera parameters over time. In this paper,... 

Multiple human 3D pose estimation is a useful but challenging task in computer vison applications. The ambiguities in estimation of 2D and 3D poses of multiple persons can be verified by using multi-view frames, in which the occluded or self-occluded body parts of some persons might be visible in other camera views. But, when cameras are moving and uncalibrated, estimating the association of multiple human body parts among different camera views is a challenging task. This paper presents novel methods for multiple human 3D pose estimation and pose association in multi-view camera frames in an uncalibrated camera setup using an adversarial learning framework. The generator is a 3D pose... 

Knowing the exact position and rotation is a crucial necessity for the navigation of autonomous robots. Even in outdoor environments GPS signals are not always accessible for estimating online rotation and position of robots. Also inertial aided navigation methods have their own defects such as the drift of gyroscope or inaccuracy of accelerometer in agile motions and environmental sensitivity of compass. In this article, we have introduced a novel online visual gyroscope that can estimate the rotation of a moving car with analyzing the images of a monocular camera installed on it. Our real time visual gyroscope utilizes an efficient method of rotation estimation between each pair of camera... 

Multiple human 3D pose estimation is a useful but challenging task in computer vison applications. The ambiguities in estimation of 2D and 3D poses of multiple persons can be verified by using multi-view frames, in which the occluded or self-occluded body parts of some persons might be visible in other camera views. But, when cameras are moving and uncalibrated, estimating the association of multiple human body parts among different camera views is a challenging task. This paper presents novel methods for multiple human 3D pose estimation and pose association in multi-view camera frames in an uncalibrated camera setup using an adversarial learning framework. The generator is a 3D pose... 

The problem of surveillance for intrusion detection in a camera sensor network is addressed in this paper. In order to save limited resources, a sensing task should involve just the right number of sensors. For a wide enough coverage area random and uniform distribution can be applied. We propose a novel method which allows reduction of number of sensors and guarantees a desired surveillance against aerial intrusion. Enhancement of the method is also offered to further reduce the number of sensors and improve the performance. ©2008 IEEE  

Tracking vehicles across nonoverlapping cameras is required by video-based intelligent transportation systems (ITS) to efficiently calculate traffic parameters; such as link travel times and origin/destination counts. In traffic monitoring applications, cameras are usually mounted far from each other to cover wide areas. As such, object features (i.e., color information, shape, and direction) change significantly from one camera to another. These space-time differences raise serious challenges on efficient tracking. In this paper, we have presented a probabilistic model to solve the multicamera tracking task in a network of disjoint view cameras, with attention paid on estimating the density... 

In this paper, intelligent traffic surveillance system as an important part of a smart resilient city is reviewed. The smart traffic control system is very important in improving the lifestyle by decreasing the traffic saturation and air pollution. Still, multi-camera vision is more helpful in implementing different automatic traffic surveillance systems. Apart from their superior features, existing multi-camera surveillance systems suffer from computational complexity and degraded accuracy. The main reason for these shortcomings arises from image processing errors. These errors depend on the image content and thus are not predictable. To overcome this shortage, three-dimensional (3D)... 

Calculation of camera projection matrix, also called camera calibration, is an essential task in many computer vision and 3D data processing applications. Calculation of projection matrix using vanishing points and vanishing lines is well suited in the literature; where the intersection of parallel lines (in 3D Euclidean space) when projected on the camera image plane (by a perspective transformation) is called vanishing point and the intersection of two vanishing points (in the image plane) is called vanishing line. The aim of this paper is to propose a new formulation for easily computing the projection matrix based on three orthogonal vanishing points. It can also be used to calculate the... 

Plasma focus is a copious source of electrons, ions, neutrons, and X-rays. SUT-PF is a 7 kJ Mather type plasma focus device. In order to study soft X-rays emitted by this device a bent crystal spectrometer has been designed and constructed based on Johann method. Before recording spectral lines, using a photodiode detector and a pinhole camera, optimum parameters for maximum emission of soft X-rays have been studied and registered. Results show that ionized Argon atomic lines mostly have wavelengths between 3 and 4 Å. Among them 1s2–1s2p transition with a wavelength of 3.943 Å represents the most intense line  

The geometry of the sensed and thus optically relevant area in the image plane of line scan cameras suggests that improvement of the overall system is possible, by joint design of optics and electronics. By a technique named Linear Fovea (LF) proposed in this paper, the optical contrast along the Line-of-Interest (LOI) in the image plane i.e. the location of the opto-electronic sensor, is optimized at the expense of contrast elsewhere. In the LF method, employing a single doubly symmetric surface, the resolved field of view (RFOV) as the merit function, is maximized, by finding appropriate Zernike coefficients describing that surface. The technique is applied on a proof-of-concept single... 

Fully automatic algorithm for estimating the 3D human pose from multiple uncalibrated cameras is presented. Unlike the state-of-the-art methods which use the estimated pose of previous frames to restrict the candidates of current frame, the proposed method uses the viewpoint of previous frame in order to obtain an accurate pose. This paper also introduces a method to incorporate pose estimation results of several cameras without using the calibration information. The algorithm employs a rich descriptor for matching purposes. The performance of the proposed method is evaluated on a soccer database which is captured by multiple cameras. The dataset of silhouettes, in which the related 3D... 

The ability of wearable cameras to continuously capture the first person viewpoint with minimal user interaction, has made them very attractive in many application domains. Wearable technology today is available and useful but not widely used and accepted due to various challenges mainly privacy concerns. In this paper, we introduce a novel efficient privacy-aware framework for wearable cameras that can protect all sensitive subjects such as people, objects (e.g, display screens, license plates and credit cards) and locations (e.g, bathrooms and bedrooms). It uses the contextual information obtained from the wearable's sensors and recorded images to identify the potential sensitive subjects... 

The goal of this paper is to describe essential criteria for image analysis of planar laser-induced fluorescence (PLIF) signals. A new image file conversion method is introduced and some typical illustrative examples showing the potential applications of the method in PLIF experiments are presented. Analysis of row, column, and total pixel counts, and the dark noise related to an image are discussed. Image segmentation, averaging and background correction can be easily done by the reported method. In our analysis it is straightforward to inspect the pixel counts and check for saturation of the camera sensors. It is also feasible to obtain a particular row or column for interpretation and it...