Performance of Sensor Fusion for Vehicular Applications

Sensor fusion is a key system in Advanced Driver Assistance Systems, ADAS. The perfor-mance of the sensor fusion depends on many factors such as the sensors used, the kinematicmodel used in the Extended Kalman Filter, EKF, the motion of the vehicles, the type ofroad, the density of vehicles, and the gating methods. The interactions between parametersand the extent to which individual parameters contribute to the overall accuracy of a sensorfusion system can be difficult to assess.In this study, a full-factorial experimental evaluation of a sensor fusion system basedon a real vehicle was performed. The experimental results for different driving scenariosand parameters are discussed and the factors that make the most impact are identified.The performance of sensor fusion depends on many factors such as the sensors used, thekinematic model used in the Extended Kalman Filter (EKF) motion of the vehicles, type ofroad, density of vehicles, and gating methods.This study identified that the distance between the vehicles has the largest impact on theestimation error because the vision sensor performs poorly with increased distance. In addi-tion, it was identified that the kinematic models had no significant impact on the estimation.Last but not least, the ellipsoid gates performed better than rectangular gates.In addition, we propose a new gating algorithm called an angular gate. This algorithmis based on the observation that the data for each target lies in the direction of that target.Therefore, the angle and the range can be used for setting up a two-level gating approachthat is both more intuitive and computationally faster than ellipsoid gates. The angulargates can achieve a speedup factor of up to 2.27 compared to ellipsoid gates.Furthermore, we provide time complexity analysis of angular gates, ellipsoid gates, andrectangular gates demonstrating the theoretical reasons why angular gates perform better.Last, we evaluated the performance of the Munkres algorithm using a full factorial designand identified that narrower gates can speedup the running time of the Munkres algorithmand, surprisingly, even improve the RMSE in some cases.The low target maneuvering index of vehicular systems was identified as the reason whythe kinematic models do not have an impact on the estimation. This finding supports the useof simpler and computationally inexpensive filters instead of complex Interacting MultipleModel filters. The angular gates also improve the computational efficiency of the overallsensor fusion system making them suitable for vehicular application as well as for embeddedsystems and robotics

Systems with Session-based Workloads: Assessing Performance and Reliability

Many systems, including the Web and Software as a Service (SaaS), are best characterized with session-based workloads. Empirical studies have shown that Web session arrivals exhibit long range dependence and that the number of requests in a session is well modeled with skewed or heavy-tailed distributions. However, models that account for session workloads characterized by empirically observed phenomena and studies of their impact on performance and reliability metrics are lacking.;For assessing performance, we use a feedback queue to account for session-based workloads in a physically meaningful way and use simulation to analyze the behavior of the Web system under Long Range Dependent (LRD) session arrival process and skewed distribution for the number of requests in a session. Our results show that the percentage of dropped sessions, mean queue length, mean waiting time, and the useful server utilization are all affected by the LRD session arrivals and the statistics of the number of requests within a session. The impact is higher in the case of more prominent long-range dependence. Interestingly, both the request arrival process and the request departure process are long-range dependent, even in the case when session arrivals are Poisson. This indicates that the LRD at the request level can be a result of the existence of sessions.;For assessing reliability, we propose a framework which integrates (1) the Web workloads defined in term of user sessions, (2) the user navigation patterns through the Web site, and (3) the reliability estimates of the Web requests based on the system architecture; then, we give a detailed reliability model of a Web system based on the proposed framework. We recognize the difficulty of solving the proposed model and use simulation to obtain the results. And last but not least, we use statistical design of experiment to quantify the results and to determine which factors have the highest impact on the system\u27s reliability. Our results show that some two-way and three-way interactions are very important for the session reliability of Web systems

DYNAMIC BEHAVIOR OF TWO ELASTICALLY CONNECTED NANOBEAMS UNDER A WHITE NOISE PROCESS

This paper investigates the almost-sure and moment stability of a double nanobeam system under stochastic compressive axial loading. By means of the Lyapunov exponent and the moment Lyapunov exponent method the stochastic stability of the nano system is analyzed for different system parameters under an axial load modeled as a wideband white noise process. The method of regular perturbation is used to determine the explicit asymptotic expressions for these exponents in the presence of small intensity noises

Dacryocystography in rabbits

Dacryocystography is a specific method of radiological examination of the nasolacrimal apparatus based on the use of a positive contrast agent, which allows the assessment of its morphology and patency. Pathological conditions of the nasolacrimal apparatus in rabbits are very common in clinical practice, and the disturbance of its patency is usually a consequence of dental diseases or respiratory infections. The aim of this article is to present the most common pathological conditions that can affect the patency of the nasolacrimal apparatus in rabbits, a detailed anatomical description of the nasolacrimal apparatus in these animals, and the technique for performing dacriyocystography

EBV Positive Gastric Carcinomas and Their Clinicopathological Characteristics

BACKGROUND: The understanding of the etiopathogenesis of gastric carcinoma (GC) can be a base for development of new therapeutic methods to reduce mortality and to increase survival in patients with GC. The percentage of Epstein - Barr virus (EBV) positive gastric carcinomas is uncertain, and the etiologic importance of EBV in the pathogenesis of GC has still not been elucidated. AIM: This study aimed to determine the percentage of EBV associated GC as well as to determine their clinicopathological characteristics. MATERIAL AND METHODS: The study included 80 patients with GC who were analysed for ethnicity, local growth of a tumour (T status), the presence of nodal metastases (N), the presence of distant metastases (M), stage of the disease and degree of carcinoma differentiation. For detection of EBV, immunostainings were performed on tumour tissue and the peripheral non-tumour gastric mucosa. RESULTS: Positive immunostaining with an antibody against EBV was found in 19 (23.75%) of the 80 patients with gastric carcinomas. EBV immunostainings were significantly different in patients with or without metastasis and between patients of Macedonian and Albanian ethnicity (p < 0.0001, p < 0.009, respectively). EBV immunoexpression was significantly associated with the presence of distant metastases and with patients of Albanian ethnicity. CONCLUSION: Association of EBV immunostainings with distant metastasis in patients with GC suggests the influence of EBV infection on the progression of gastric carcinoma. Due to scarce and doubtful literature data on EBV associated GC, further studies are necessary to determine the role of EBV regarding aetiology, treatment and prognosis in patients with EBV associated gastric carcinoma

Radiološki pregled zuba kunića – tehnike pregleda i interpretacija snimki

Patološka su stanja zuba kunića u svakodnevnoj kliničkoj praksi vrlo česta i često rezultiraju poremećajem u funkciji organa probavnog i respiratornog sustava, a mogu imati i letalan ishod. Da bi se omogućila pravovremena primjena terapije i spriječila pojava komplikacija, posebnu pažnju treba usmjeriti na ranu dijagnostiku. Radiološka dijagnostika predstavlja jednostavan, brz i nezaobilazan postupak u procjeni stanja zubi. Za razliku od drugih vrsta sisavaca, radiološki pregled zuba kunića se odlikuje određenim osobitostima koje se, prije svega, očituju u tehnikama snimanja i interpretaciji rendgenskih snimaka koji su detaljno prikazani u ovom radu

Expression of matrix metalloproteinases 2, 7 and 9 in patients with colorectal cancer

Background/Aim. Matrix metalloproteinases (MMPs) are perceived to play a key role in tumor invasion and metastasis by their capacity to degrade basement membranes and extracellular matrix proteins. The aim of this study was to investigate the expressions of MMP-2, MMP-7 and MMP-9 in tumor tissue and their relation to clinicopathologic features in patients with colorectal cancer. Methods. Specimens of resected colorectal cancer and surrounding normal tissue of 82 patients were immunohistochemically stained for MMP-2, MMP-7 and MMP-9. The results of immunohistochemical expression of MMPs were correlated with some clinical and pathologic parameters. Results. Immunohistochemical expression of MMP-2 was more frequent in the patients with higher preoperative serum levels of carcinoembryonic antigen (CEA) (p = 0.047), MMP-2 (p = 0.018), MMP-9 (p = 0.036) and in those with lymph node metastasis (p = 0.018) and the advanced stage of the disease (p = 0.046). Expression of MMP-7 was more frequent in the patients with elevated preoperative serum levels of: CEA (p = 0.012), MMP-7 (p = 0.036), MMP-9 (p = 0.023) and with deeply invasive neoplasms (p = 0.027). MMP-9 cell expression was in a positive correlation with elevated preoperative serum levels of: CEA (p = 0.013), MMP-2 (p = 0.012), MMP-9 (p = 0.018) and depth of CRC invasion, i.e. Tparameter (p = 0.027). Conclusion. Immunohistochemical expression of MMPs is a useful indicator of the disease development and progression in patients with colorectal cancer

Serum Matrix Metalloproteinase-2, -7 and -9 (MMP-2, MMP-7, MMP-9) levels as Prognostic Markers in Patients with Colorectal Cancer

<p><strong>Introduction:</strong> Matrix metalloproteinases are produced by tumour cells, hence, they may be associated with tumour progression including invasion, migration, angiogenesis and metastasis. Finding prognostic markers to better identify patients with higher risk for poor survival would be valuable in order to customize pre- and postoperative treatment as well as to enable closer follow-up of these patients. Aim of our study was to examine<br />MMP-2, MMP-7 and MMP-9 serum levels and correlated them with pathological data such as stage of the colorectal cancer (CRC) and outcome.</p><p><strong>Methods: </strong>The investigation included 82 patients with operable CRC without distant metastases, who had underwent blood tests in order to determine the MMP-2, MMP-7 and MMP-9 serum levels in the following time periods: preoperatively, 3, 6, 9 and 12 months postoperatively.</p><p><br /><strong>Results</strong>: The values of the investigated MMPs decrease postoperatively and start to increase 6 month later in patients of all stages of the disease, reaching the highest value 12 month postoperatively with statistically important differences of MMP-2, MMP-7 and MMP-7 serum levels in terms of disease staging and defined points of time. Analysis of the results showed that the MMP-2 serum levels obtained 3 and 12 months postoperatively,<br />than MMP-7 serum levels 12 months postoperatively and the MMP-9 serum levels in all analyzed points in time were in significant association with the CRC patients’outcome.</p><p><br /><strong>Conclusion: </strong>The MMP-2, MMP-7 and especially MMP-9 serum values could be important indicators for diagnosis of the patients with CRC and for monitoring of disease progression.</p