Static Segment Research Articles

Efficient Utilization of Bandwidth in Static Segment of FlexRay Protocol

Efficient Utilization of Bandwidth in Static Segment of FlexRay Protocol

Measurement of two phase flow concentration with a novel pressure difference method. I: Principle

Traditionally, the measurement of the concentration of a two-phase flow by gauging differential pressure is subject to pressure loss due to the flow friction along the pipe wall. A novel pressure difference method against this issue was proposed in this paper. A theoretic model is developed for the method, from the principle of hydrostatics of particle gravitational settlement. The method was essentially validated with an experiment of particle settling in a stand-alone pipe section by sealing the two terminals to form a static gas-solid two phase medium and supported with a numerical simulation based on a Lagrangian model as well. Inherently, the method is expected to measure the concentration of a two phase flow in a pneumatic conveying pipe, correspondingly by setting a flow branch which contains an erect settlement tube with two dynamically shutting valves to form a transient static particle deposition segment.

Experimental determination of the fatigue behavior of dowel strips in ortho‐composite slabs for road bridges

AbstractIn contrast to reinforced concrete and conventional composite bridges, the orthotropic steel deck slab offers a high load‐bearing capacity combined with a low dead weight. It is therefore ideally suited for slender and long‐span structures. However, the notch sharpness in the details and drastically increased traffic loads led to extensive fatigue damage and, as a consequence, often to premature repair or replacement work. With the ortho‐composite slab a lightweight and robust construction is currently being developed as an alternative. It combines the significant advantages of a low dead weight, long service life and economical production. The construction consists of a modified orthotropic stiffened steel plate and a thin, single‐layer reinforced in‐situ concrete. Composite dowel strips (CDS) with a clothoid shape are provided as shear connectors. In this paper, the experimental test program will be introduced. It comprises static push‐out tests on CDS in longitudinal and transverse directions as well as static and cyclic beam and segment tests. The focus lies on the test set‐ups, sample preparations, measurement concepts and the results of the so‐called beam tests. The investigations presented here were carried out as part of the AiF‐FOSTA research project P1265 [1].

Design of Generalized Enhanced Static Segment Multiplier with Minimum Mean Square Error for Uniform and Nonuniform Input Distributions

In this paper, we analyze the performances of an Enhanced Static Segment Multiplier (ESSM) when the inputs have both uniform and non-uniform distribution. The enhanced segmentation divides the multiplicands into a lower, a middle, and an upper segment. While the middle segment is placed at the center of the inputs in other implementations, we seek the optimal position able to minimize the approximation error. To this aim, two design parameters are exploited: m, defining the size and the accuracy of the multiplier, and q, defining the position of the middle segment for further accuracy tuning. A hardware implementation is proposed for our generalized ESSM (gESSM), and an analytical model is described, able to find m and q which minimize the mean square approximation error. With uniform inputs, the error slightly improves by increasing q, whereas a large error decrease is observed by properly choosing q when the inputs are half-normal (with a NoEB up to 18.5 bits for a 16-bit multiplier). Implementation results in 28 nm CMOS technology are also satisfactory, with area and power reductions up to 71% and 83%. We report image and audio processing applications, showing that gESSM is a suitable candidate in applications with non-uniform inputs.

Pakistan sign language to Urdu translator using Kinect

The lack of a standardized sign language, and the inability to communicate with the hearing community through sign language, are the two major issues confronting Pakistan's deaf and dumb society. In this research, we have proposed an approach to help eradicate one of the issues. Now, using the proposed framework, the deaf community can communicate with normal people. The purpose of this work is to reduce the struggles of hearing-impaired people in Pakistan. A Kinect-based Pakistan sign language (PSL) to Urdu language translator is being developed to accomplish this. The system’s dynamic sign language segment works in three phases: acquiring key points from the dataset, training a long short-term memory (LSTM) model, and making real-time predictions using sequences through openCV integrated with the Kinect device. The system’s static sign language segment works in three phases: acquiring an image-based dataset, training a model garden, and making real-time predictions using openCV integrated with the Kinect device. It also allows the hearing user to input Urdu audio to the Kinect microphone. The proposed sign language translator can detect and predict the PSL performed in front of the Kinect device and produce translations in Urdu.

Pakistan sign language to Urdu translator using Kinect

The lack of a standardized sign language, and the inability to communicate with the hearing community through sign language, are the two major issues confronting Pakistan's deaf and dumb society. In this research, we have proposed an approach to help eradicate one of the issues. Now, using the proposed framework, the deaf community can communicate with normal people. The purpose of this work is to reduce the struggles of hearing-impaired people in Pakistan. A Kinect-based Pakistan sign language (PSL) to Urdu language translator is being developed to accomplish this. The system’s dynamic sign language segment works in three phases: acquiring key points from the dataset, training a long short-term memory (LSTM) model, and making real-time predictions using sequences through openCV integrated with the Kinect device. The system’s static sign language segment works in three phases: acquiring an image-based dataset, training a model garden, and making real-time predictions using openCV integrated with the Kinect device. It also allows the hearing user to input Urdu audio to the Kinect microphone. The proposed sign language translator can detect and predict the PSL performed in front of the Kinect device and produce translations in Urdu.

Efficient Design of Rounding Based Static Segment Imprecise Multipliers for Error Tolerance Application

Efficient Design of Rounding Based Static Segment Imprecise Multipliers for Error Tolerance Application

A Novel Low-Power High-Precision Implementation for Sign–Magnitude DLMS Adaptive Filters

This paper investigates the use of approximate fixed-width and static segment multipliers in the design of Delayed Least Mean Square (DLMS) adaptive filters based on the sign–magnitude representation for the error signal. The fixed-width approximation discards part of the partial product matrix and introduces a compensation function for minimizing the approximation error, whereas the static segmented multipliers reduce the bit-width of the multiplicands at runtime. The use of sign–magnitude representation for the error signal reduces the switching activity in the filter learning section, minimizing power dissipation. Simulation results reveal that, by properly sizing the two approaches, a steady state mean square error practically unchanged with respect to the exact DLMS can be achieved. The hardware syntheses in a 28 nm CMOS technology reveal that the static segmented multipliers perform better in the learning section of the filter and are the most efficient approach to reduce area occupation, while the fixed-width multipliers offer the best performances in the finite impulse response section and provide the lowest power dissipation. The investigated adaptive filters overcome the state-of-the-art, exhibiting an area and power reduction with respect to the standard implementation up to −18.0% and −64.1%, respectively, while preserving the learning capabilities.

Exploiting temporal changes in query submission behavior for improving the search engine result cache performance

A commonly used technique for improving query response time in retrieval systems is storing query-relevant information in a fast access memory storage such as a result cache. The effectiveness of the result cache heavily relies on giving correct admission and eviction decisions, which require careful analysis of query and stream characteristics. Due to anonymous and global user access patterns, search engines are often considered time-invariant architectures: query characteristics are frequently collected globally, and assumed to be unchanging for long periods of time. However, the highly distributed nature of the modern search engine framework consequently led to noticeable temporal changes in user access patterns through short periods of time for each of the data center within the distributed network.The work presented here attempts to evaluate temporal variations in query submissions and exploit them in order to improve the result caching performance. To this end, query logs are analyzed in order to verify the availability of such variations and a new caching framework that facilitate these changes is proposed. The proposed framework partitions the result cache into three segments: a static segment that stores the most frequent queries in an offline fashion, a newly introduced semi-static segment on top of the state-of-the-art Static–Dynamic Cache (SDC) that changes content during different periods of the day, and a dynamic segment that is maintained in an Least Recently Used (LRU) fashion. Conducted experiments demonstrate that the proposed caching framework improves the hit rate of a search engine result cache up to 3.31% and query response time up to 7.27% with respect to the state-of-the-art techniques.

Detection of primary angleclosure suspect with different mechanisms of angle closure using multivariate prediction models.

PurposeWe had found that a multivariate prediction model used for the detection of primary angle‐closure suspects (PACS) by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters had an area under the receiver operating characteristic curve (AUC) of 0.844. We undertook this study to evaluate this method in screening of PACS with different dominant mechanisms of angle closure (AC).MethodsThe right eyes of subjects aged ≥40 years who participated in the 5‐year follow‐up of the Handan Eye Study and had undergone gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analysed by the Zhongshan Angle Assessment Program. The dominant AC mechanism in each eye was determined to be pupillary block (PB), plateau iris configuration (PIC) or thick peripheral iris roll (TPIR). Backward logistic regression (LR) was used for inclusion of variables in the prediction models. LR, Naïve Bayes’ classification (NBC) and neural network (NN) were evaluated and compared using the AUC.ResultsData from 796 subjects (413 PACS and 383 normal eyes) were analysed. The AUCs of LR, NBC and NN in the PB group were 0.920, 0.918 and 0.917. The AUCs of LR, NBC and NN in the PIC group were 0.715, 0.708 and 0.707. The AUCs of LR, NBC and NN in TPIR group were 0.867, 0.833 and 0.886.ConclusionsPrediction models showed the best performance for detection of PACS with PB mechanism for AC and have potential for screening of PACS.

High Performance Approximate Memories for Image Processing Applications

Efficient utilization of on-chip Static Random Access Memory (SRAM) space is more important on processor core design in modern Field Programmable Gate Array (FPGA) based Digital Signal Processing (DSP) applications. In the proposed High-performance Approximate Single Port (HASP) SRAM architecture, a significant amount of data is stored to achieve high performance. The constraints involved with high performance are counterbalanced to provide high accuracy, high speed, low power and area efficiency. In the proposed High-performance Approximate Sub-Bank Dual Port (HASBDP1 and HASBDP2) memory architectures, HASP has been employed and modified to work as a True DP SRAM with energy and area efficiency. The performance of the proposed memories is investigated by comparing its speed, area and power with those of the existing approaches. The proposed HASP SRAM provides 14.99% less power consumption and thirteen numbers of logic elements savings in the resource utilization than the existing conventional SP SRAM. By considering the design metrics, the proposed HASBDP SRAMs outperform than the conventional TDP and sub-bank DP SRAMs approaches. The proposed HASBDP2 exhibits 29.09%, 22.37% higher PSNR and 32.94%, 28.48% higher SSIM than the truncated least significant bit and static segment on-chip approximate memories respectively.

Establishment and Comparison of Algorithms for Detection of Primary Angle Closure Suspect Based on Static and Dynamic Anterior Segment Parameters.

PurposeTo establish and evaluate algorithms for detection of primary angle closure suspects (PACS), the risk factor for primary angle closure disease by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters.MethodsObservational, cross-sectional study. The right eyes of subjects aged ≥40 years who participated in the 5-year follow-up of the Handan Eye Study, and underwent gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analyzed by Zhongshan Angle Assessment Program. Backward logistic regression (BLR) was used for inclusion of variables in the prediction models. BLR, naïve Bayes’ classification (NBC), and neural network (NN) were evaluated and compared using the area under the receiver operating characteristic curve (AUC).ResultsData from 744 subjects (405 eyes with PACS and 339 normal eyes) were analyzed. Angle recess area at 750 µm, anterior chamber volume, lens vault in light and iris cross-sectional area change/pupil diameter change were included in the prediction models. The AUCs of BLR, NBC, and NN were 0.827 (95% confidence interval [CI], 0.798-0.856), 0.826 (95% CI, 0.797-0.854), and 0.844 (95% CI, 0.817-0.871), respectively. No significant statistical differences were found between the three algorithms (P = 0.622).ConclusionsThe three algorithms did not meet the requirements for population-based screening of PACS. One possible reason could be the different angle closure mechanisms in enrolled eyes.Translational RelevanceThis study provides a promise for basis for future research directed toward the development of an image-based, noncontact method to screen for angle closure.

Fractional Dynamic Caching: A Collaborative Design of Storage and Backhaul

To reduce the average file delivery time under limited backhaul bandwidth and cache storage, we propose a fractional dynamic caching scheme, that coordinates the utilization of the backhaul and the cache storage. In the proposed scheme, only part of each file is pre-fetched and stored in the static storage segment of small base stations (SBSs), while remaining part of the file will be fetched into the dynamic storage segment when requested by users. We aim to minimize the average file delivery time by investigating the optimal prefetching policy, i.e., the size of the pre-fetched part of each file and the size of the dynamic storage. We formulate the file delivery time minimization problem as a convex optimization formulation. We compute the closed-form of the optimal pre-fetching policy when the wireless rate is constant. Then, a heuristic pre-fetching policy is derived, using the conditional average wireless rate. To overcome the issue that file popularity may be unknown or time-varying, we further provide an approximation of the heuristic pre-fetching policy which is irrelevant to the file popularity. We also discuss on the potential application of the proposed caching scheme in scenarios with heterogeneous file sizes. Numerical results show that the proposed scheme can substantially improve the backhaul utilization efficiency, and reduce the average file delivery time. The heuristic pre-fetching policy has similar performance with the optimal pre-fetching policy yet with much lower complexity.

Visual Servo-Collision Avoidance Hybrid Task by Considering Detection and Localization of Contact for a Soft Manipulator

Due to the features of soft material, such as softness, deformability, and adaptability to constrained surroundings, soft manipulators can collide with external objects to some extent. To take the best advantage of this merit, this article presents a method of visual servo considering collisions with obstacles for a soft manipulator. First of all, a collision detection algorithm is proposed using shape feedbacks obtained by a sensor network, on the basis of the assumption that the manipulator can be considered as a combination of a static segment and a dynamic segment. Then, a contact localization algorithm is proposed to pinpoint the position where the collision occurs by minimizing the differences between the theoretical and actual shapes. An obstacle get-away algorithm, which is achieved by driving the calculated contact point to a desired position, is presented to avoid the obstacle. Along with the visual servo, a controller taking the obstacle avoidance into account is proposed to perform the hybrid task, with its stability validated via Lyaponov criterion. Finally, simulations and physical experiments are carried out to evaluate the algorithms. It is shown that the pixel error can converge to zero and the distance from the obstacle with respect to the contact point increases obviously in a short time.

Five-year changes in anterior segment parameters in an older population in urban southern China: the Liwan Eye Study

PurposeTo investigate the 5-year changes in static and dynamic anterior segment optical coherence tomography (AS-OCT) parameters and their predictors.MethodsThis was a prospective, population-based cohort study of people aged 50 years...

Security-Aware Scheduling for FlexRay-Based Real-Time Automotive Systems

FlexRay is a hybrid communication protocol tailored to the requirements of safety-critical distributed real-time automotive systems, providing support for the transmission of time-critical periodic frames in a static segment and event-triggered frames in a dynamic segment. With the development of intelligence and networking of vehicles, such systems are becoming increasingly connected to external environments; thus, security has become a pressing issue in system design. However, FlexRay-based architecture does not have direct support for secure communication. When deploying the security mechanisms on these architectures, a primary challenge is to guarantee the schedulability of systems, given the tight resource constraints and strict timing constraints. In this paper, we apply an authentication mechanism based on the delayed exposure of one-way key chains to protect the authenticity of messages on FlexRay and make a slight modification to reduce the authentication delay. On that basis, we propose a mixed integer linear programming formulation for solving the scheduling problem of FlexRay-based real-time automotive systems subject to both authentication mechanism constraints and other traditional design constraints. Experimental results demonstrate the effectiveness and efficiency of the proposed method in system design and indicate the necessity of collaborative design between security and other functionalities.

Novel Approach for the Lifetime Prediction of Composite Materials under Static Loads

Composite materials in structural applications that are subjected to static loads for several decades tend to change material performance over their lifetime. Classical creep tests with constant static loading are quite simple tests with low demands on the test equipment. Unfortunately, these tests require uneconomically long test times, which is why a shortening of the test times with various accelerated approaches is being researched. Within this work two approaches for reduction of the testing time were investigated. On the one hand a fatigue test with the variation of R-ratio and following extrapolation to an R-ratio of 1 was done. On the other hand a Stress Rate Accelerated Creep Rupture Test (SRCR) was developed, where a defined initial stress σi is applied at the beginning of the loading process, followed by an increase load with a constant rate instead of the static stress segment of the classic creep rupture tests. Changing the load rate in several individual tests leads to stress rate-dependent fracture strengths with associated fracture times, which allows extrapolation to a fracture time at a load rate of zero. In particular, the approach of the SRCR offers great potential for greatly reducing test times with an acceptable prediction quality.

Stress analysis of Al2014-T6 riveted splice joint fuselage structure using finite element analysis

This work describes about the stress of a splice joint in a medium transport aircraft. Typical splice joint panel forming part of a fuselage, consisting of skin plates are riveted is considered for the study. The calculations have been performed by considering the cabin pressurization load on the panel. Aluminium alloy 2014 - T6 material considered for structural elements of the panel. Two dimensional finite element analyses have been carried out on the splice joint panel. The distribution of fasteners loads and local stress field at rivet locations read using element analysis. The global finite element analysis linear static analysis first segment of typical fuselage will be carried out. The Global finite element analysis results will be benchmark for comparing the result from the splice joint panel analysis. Repeated finite element analysis will be carried out to get the response of the parent structure fuselage find location the maximum stress location will be identified from the analysis.

A Reliability Scheduling Algorithm for the Static Segment of FlexRay on Vehicle Networks.

FlexRay is a next-generation in-vehicle communication protocol which works in real time with flexibility. The most common applications in FlexRay are high bandwidth. X-by-wire applications, such as brake by wire and throttle by wire. However, there is no mechanism which can prevent transient faults in the application layer of FlexRay. If a transient fault occurs during driving, this would be very dangerous; therefore, we propose a fast reliability scheduling algorithm (FRSA) to improve the communication reliability of FlexRay. The proposed method reduces the probability of transient faults in one clock cycle by using a retransmission mechanism to recover the transient errors, and further improves computational complexity using the lookup table method to ensure system reliability. In this paper, we analyze a related literature to establish the system reliability constraints needed to evaluate the necessary time and slot usage, and the proposed cost function is used to evaluate the performance and efficiency when the number of messages is increased. Experimental results show that the proposed FRSA reduces execution time by an average 70.76% and cost by an average 13.33% more than the other existing methods. This method can be useful to others, especially regarding research about periodic time-triggered communication systems.

Research of Message Scheduling for In-Vehicle FlexRay Network Static Segment Based on Next Fit Decreasing (NFD) Algorithm

FlexRay is becoming the in-vehicle communication network of the next generation. In this study, the main contents are the FlexRay network static segment scheduling algorithm and optimization strategy, improve the scheduling efficiency of vehicle network and optimize the performance of communication network. The FlexRay static segment characteristic was first analyzed, then selected bandwidth utilization as the performance metrics to scheduling problem. A signal packing method is proposed based on Next Fit Decreasing (NFD) algorithm. Then Frame ID (FID) multiplexing method was used to minimize the number of FIDs. Finally, experimental simulation by CANoe. FlexRay software, that shows the model can quickly obtain the message schedule of each node, effectively control the message payload size and reduced bus payload by 16.3%, the number of FID drops 53.8% while improving bandwidth utilization by 32.8%.