Color vision deficiency is a surprisingly frequent vision impairment, but not considered to be a mayor eye disease due to being inherited condition and not progressive condition. However it poses serious restrictions on a visually impaired person because vision deficiency tests are commonly used to disqualify individuals affected by color vision deficiency from certain occupations. Color vision deficiency cannot be cured, thus it is important to develop suitable assistive technology to overcome the restrictions it poses. Virtual reality can project custom and separate images to both eyes in a real-time and thus enabling a new class of assistive technology that can deliver visual information in a highly customized manner. Virtual reality based assistive technology is promising for age-related macular degeneration, diabetic retinopathy and particularly for color vision deficiency. Virtual reality prototype is created based on a video see-through setup using commercial virtual reality headset and stereo camera. The prototype uses custom image processing to transform visual information from the camera to color vision deficiency friendly form. Time-domain color mapping real-time image processing is proposed to improve scores on standard color vision deficiency tests - Ishihara tests. Experiment is conducted to evaluate a protanope time-domain color mapping with sinusoidal envelope.
The trajectory of a moving object may be extracted from video using image processing algorithms. However, the quality of the extracted information largely depends on the frame rate and exposure time of the camera, thus it is difficult to capture fast movement using slower and less expensive cameras. To this end, we propose to use an active modulated light source for object tracking, interacting with exposure times and subsampling existing frames. A prototype of a multi-functional active visual marker is presented in this paper. The system is based on the ESP-WROOM-32 microcontroller, which is configured to use various communication protocols, namely WiFi 802.11, RF 2.4 GHz GFSK and RS485. The microcontroller controls the RGB LED, which is used as light source. In addition, the system can be synchronized with the external real-time clock. The experimental results have illustrated the advantages and disadvantages of the designed active markers and pointed out the directions for future work and development.
Computer vision systems are frequently used for inspection and classification of products during manufacturing. Image processing and analysis allows non-invasive extraction of object features within an image and the classification of objects based on the extracted data. Shape, texture and color are typical features that can be extracted from an image and used for object recognition. In this paper, a method of detection, segmentation and classification of resistors captured in digital image, based on their nominal values, is presented. The process consists of the following steps: image segmentation, morphological image processing, representation and description of objects, object features extraction, classification of extracted data using support vector machines (SVM). Experimental results show that the proposed method exhibits solid performance and real-time operating capabilities.
The self-blast type circuit breaker has been developed to reduce mechanical operation energy by building up the pressure of arc extinguishing gas flow from the heat of the arc itself. Unlike a puffer type, breaking performance for self-blast type are influenced and sensitive by various factors inside interrupter parts, such as the nozzle structure, chamber shape as well as amplitude of short circuit current. These days, particularly, it has been difficult to secure a low current breaking performance as the circuit breaker has been compacted. The currents for breaking test duties belong to from 10% to 30% of the rated breaking current in accordance with IEC standard. Although the arc energy for interruption is lower than the rated breaking current test duties, the breaking performance could be lower than the tests because the transient recovery voltage (TRV) after the current zero is relatively high. The capability of interruption is related to dielectric recovery after the arc quenching. Therefore, a complex analytical method is needed to secure the breaking performance for the current and to improve the performance by using the limited gas flow inside the interrupter parts. In this paper, it described the techniques to verify breaking performance such as hot gas flow analysis and dielectric analysis. And it has studied a method for improving the performance with various design parameters using computational fluid dynamics (CFD) programs and high power laboratory test. Finally, this paper shows us the improvement of dielectric recovery performance for the self-blast type circuit breaker.
The breakdown voltage during interruption of capacitive currents is defined by two physical quantities: the electric field and the gas density field, which are calculated in different calculation domains and using different mashes. In order to calculate the breakdown voltage, it is necessary to map these two mashes and calculate the ratio density/electric field in every calculation point. The straightforward solution is to pair each density cell with the nearest cell from the electric field mesh, based on their coordinates. Although this solution gives good results, it is very time consuming. Therefore, this paper presents a new approach for mapping of two meshes based on the algebra of fractal vector, so called Bosnian algebra. This approach does not search the meshes for the closest pair based on the coordinates of each point, but instead uses only the assigned cell indexes and simple fractal operations to determine the neighboring cells. This way, the search for the nearest pair is much more efficient and faster.
Abstract Background An optimal adjuvant treatment of HER2 positive breast cancer includes the initiation of trastuzumab within 6 months after the surgery. However, due to limited resources and waiting lists, this timeframe is often exceeded in developing countries. We previously reported short-term outcomes of a time-optimal versus delayed postoperative initiation of trastuzumab in women with HER2 positive, non-metastatic, neoadjuvant naive breast cancer. Here, we report an extended follow-up, summarizing outcomes of our cohorts. Methods We included 223 consecutive women with surgically treated, non-metastatic, neoadjuvant naive, HER2 positive breast cancer from 2009 to 2011, from four institutions in Bosnia and Herzegovina. Patients were assigned to a time-optimal group (TOG), or a delayed group 1 (DG1), or a delayed group 2 (DG2), depending on whether their adjuvant trastuzumab was initiated 6 months, or 6-12 months, or more than 12 months after the surgery, respectively. A cut-off point for the follow-up was January 2019. We compared clinical outcomes between the groups, taking into account lymph node status. Results The patient’s median age was 55 (range 27-80) years. Mean follow-up period was 67 (range 4-109) months. Node-negative disease was found in 38.6% patients overall. 37% (TOG) patients received trastuzumab within 6 months, while 41% (DG1) received it within 6-12, and 22% (DG2) more than 12 months after their surgery. A higher number of node negative patients was found in the DG2 group compared to the TOG and DG1 groups (48%, 35%, and 36% respectively). 5-year DFS rate was 70.73% (TOG), 67.03% (DG1), and 62.00% (DG2). The OS rate was 78.05% (TOG), 75.82% (DG1), and 74.00% (DG2). Conclusions From the above, a conclusion can be made that patients with time-optimal initiation of adjuvant trastuzumab therapy had a higher 5-year DFS and OS rate compared to the delayed treatment initiation groups. Results of the DG1 and the DG2 group indicate that trastuzumab therapy shows a persistent benefit even if administered with a delay. Higher DFS and OS rates in the DG2 group could be explained by a higher number of node-negative low-risk, patients in this group. Legal entity responsible for the study The authors. Funding Roche. Disclosure S. Beslija: Advisory / Consultancy, Research grant / Funding (self), Travel / Accommodation / Expenses: Roche; Advisory / Consultancy: Novartis; Advisory / Consultancy: MSD; Advisory / Consultancy, Travel / Accommodation / Expenses: Pfizer. T. Ceric: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Advisory / Consultancy: MSD; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Novartis. B. Hasanbegovic: Advisory / Consultancy: Roche. A. Pasic: Advisory / Consultancy: Merck; Advisory / Consultancy: Sanofi. All other authors have declared no conflicts of interest.
Introduction: Inappropriate design of experimental studies in medicine inevitably leads to inaccurate or false results, which serve as basis for erroneous and biased conclusions. Aim The aim of our study was to investigate prevalence of implementing basic principles of experimental design (local control, replication and randomization) in preclinical experimental studies, performed either on animals in vivo, or animal/human material in vitro. Material and Methods Preclinical experimental studies were retrieved from the PubMed database, and the sample for analysis was randomly chosen from the retrieved publications. Implementation rate of basic experimental research principles (local control, randomization and replication) was established by careful reading of the sampled publications and their checking against predefined criteria. Results Our study showed that only a minority of experimental preclinical studies had basic principles of design completely implemented (7%), while implementation rate of single aspects of appropriate experimental design varied from as low as 9% to maximum 86%. Average impact factor of the surveyed studies was high, and publication date relatively recent, suggesting generalizability of our results to highly ranked contemporary journals. Conclusion Prevalence of experimental preclinical studies that did not implement completely basic principles of research design is high, raising suspicion to validity of their results. If incorrect and biased, results of published studies may mislead authors of future studies and cause conduction of fruitless research that will waste precious resources.
Nakagami-m probability density function (pdf) is one of the frequently used distributions for describing fast received signal variations in radio channels, obtained as a result of multipath phenomenon. It is foremost derived by assuming the most general multipath channel model but applying mathematical approximations. Afterward, it is derived without approximations, but based on dedicated physical models with many constraints. Consequently, neither approach can be considered both, universally applicable and exact. Accordingly, in this paper, a novel approach in deriving Nakagami-m pdf is provided, being based on fewer constraints on propagation phenomena than others. Herein, it is shown that Nakagami-m pdf can be obtained as a distribution of a Euclidean distance of a point orthogonally projected from homogeneous distributed n-dimensional hypersphere on N-dimensional space, where received signal envelope is interpreted as mentioned Euclidean distance, with $n$ being a total number of orthogonal multipath components which can reach the receiver in idealized condition and $N$ being a number of these components which reach the receiver in reality (with N < n).
The success of fundamental network tasks of traffic delivery from a source to a destination node is mainly dependent on the efficiency of the routing protocol. In mobile ad hoc networks, the effectiveness of routing protocols is additionally demanding due to the dynamic nature of network nodes. In this paper, we dealt with the exploitation of the routes generated using DSDV bellman-ford routing protocol. Through a total of 3960 network simulations with different topologies, network loads and mobility nodes, various parameters of the DSDV were considered. Our results show that there are a large number of unused routes, and techniques for improving the efficiency of routing and reducing routing overhead can be implemented.
The vision of the smart-city environment is based on a large number of sensors, actuators, devices connected to the Internet. As interest in the practical implementation of the smart city environment increases, so does the interest in examining network connectivity which can be useful for investigating security vulnerabilities, identifying or blocking traffic accessibility (when needed), and other. In this paper, we analyze the network connectivity of smart-home Xiaomi solutions based on measurements made over 30 days. We analyze the installation phase, the usage phase, and identify key Xiaomi network nodes using geolocation techniques.
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