Simple Robust PID Tuning for Magnetic Levitation Systems Using Model-free Control and $${{\cal H}_\infty}$$ ℋ ∞ Control Strategies

International Journal of Control, Automation and Systems - This paper proposes two control techniques to provide robust tracking for magnetic levitation systems (MLS): model-free control (MFC) and...     

Effect of kinesthetic and tactile haptic feedback on the quality of experience of edutainment applications

Haptic technologies and applications have received enormous attention in the last decade. The incorporation of haptic modality into multimedia applications adds excitement and enjoyment to an application. It also adds a more natural feel to multimedia applications, that otherwise would be limited to vision and audition, by engaging as well the user’s sense of touch, giving a more intrinsic feel essential for ambient intelligent applications. However, the improvement of an application’s Quality of Experience (QoE) by the addition of haptic feedback is still not completely understood. The research presented in this paper focuses on the effect of haptic feedback and what it potentially adds to the experience of the user as opposed to the traditional visual and auditory feedback. In essence, it investigates certain issues regarding stylus-based haptic education applications and haptic-enhanced entertainment videos. To this end, we used two haptic applications: the haptic handwriting learning tool to experiment with force feedback haptic interaction and the tactile YouTube application for tactile haptic feedback. In both applications, our analysis shows that the addition of haptic feedback will increase the QoE in the absence of fatigue or discomfort for this category of applications. This implies that the incorporation of haptic modality (both force feedback as well as tactile feedback) has positively contributed to the overall QoE for the users.     

Targeting spam control on middleboxes: Spam detection based on layer-3 e-mail content classification

This paper proposes a spam detection technique, at the packet level (layer 3), based on classification of e-mail contents. Our proposal targets spam control implementations on middleboxes. E-mails are first pre-classified (pre-detected) for spam on a per-packet basis, without the need for reassembly. This, in turn, allows fast e-mail class estimation (spam detection) at receiving e-mail servers to support more effective spam handling on both inbound and outbound (relayed) e-mails. In this paper, the naïve Bayes classification technique is adapted to support both pre-classification and fast e-mail class estimation, on a per-packet basis. We focus on evaluating the accuracy of spam detection at layer 3, considering the constraints on processing byte-streams over the network, including packet re-ordering, fragmentation, overlapped bytes, and different packet sizes. Results show that the proposed layer-3 classification technique gives less than 0.5% false positive, which approximately equals the performance attained at layer 7. This shows that classifying e-mails at the packet level could differentiate non-spam from spam with high confidence for a viable spam control implementation on middleboxes.     

Multilayer array illuminators with binary phase plates at fractional Talbot distances

We describe a Talbot array illuminator made of cascaded binary phase plates located at fractional Talbot distances. We compare the performance of such an illuminator with a conventional single-layer Talbot array illuminator in terms of compression ratio and technical feasibility.     

Characteristics of the medical waste generated at the Jordanian hospitals

Recently, Jordan has witnessed increased amounts of medical waste generated at different healthcare facilities. This has resulted in issuance of Medical Waste Regulation that aimed at regulating the management processes of such hazardous waste. To provide information on medical waste generation rates, composition and statistical characteristics, a comprehensive sampling survey was initiated after a regulatory definition of the medical waste was established. Hospitals from Public, private and educational categories were covered by the survey. This paper presents the findings of the survey. The average generation rates ranged from 0.29 to 1.36 kg/bed/day, while in terms of patient numbers it is from 0.36 to 0.87 kg/patient/day. The total daily amount of medical waste generated at the Jordanian hospitals was estimated to be 6 tones/day. The daily amounts of medical waste generated at King Abdullah University Hospital were found to follow a log normal probability distribution. Physical composition analysis of the medical waste, which conducted based on the categories identified by the Jordanian Regulation, indicated that the infectious waste category is the highest, followed by sharps category and finally pathological, cytotoxic and pharmaceutical categories were the lowest. The study concluded that all hospitals covered by the survey are practicing segregation of hazardous medical waste from general medical waste. However, the segregation process in some hospitals is still inefficient and there is a potential for improvements toward minimizing the hazardous medical waste generation.     

Optimal and heuristic solution methods for a multiprocessor machine scheduling problem

This paper deals with the scheduling of operations on a multiprocessor machine in the context of shoe manufacturing. Multiprocessor machines are composed of several parallel processors. Unlike parallel machines, the entire machine needs to be stopped whenever a single processor needs a setup. Our industrial partner, one of the major winter-shoe manufacturers in Canada, offers a relatively large variety of models. For each of these models, all the sizes proposed by this manufacturer must be produced in various quantities. Our objective is to schedule the production of the required sizes on the machine's different processors in order to minimize the global makespan, which includes both the production time and the set up time. We first present a mathematical formulation of the problem. Then, we introduce a decomposition procedure based on the mathematical model, and we demonstrate that this procedure is very efficient for small- and medium-size instances. We also propose two construction heuristics and two improvement heuristics for larger problems, and we report the results of our extensive computational experiments to demonstrate the quality of the proposed heuristics in terms of reducing production time and computational effort.     

A hierarchical design methodology for full-search block matching motion estimation

Many useful DSP algorithms have high dimensions and complex logic. Consequently, an efficient implementation of these algorithms on parallel processor arrays must involve a structured design methodology. Full-search block-matching motion estimation is one of those algorithms that can be developed using parallel processor arrays. In this paper, we present a hierarchical design methodology for the full-search block matching motion estimation. Our proposed methodology reduces the complexity of the algorithm into simpler steps and then explores the different possible design options at each step. Input data timing restrictions are taken into consideration as well as buffering requirements. A designer is able to modify system performance by selecting some of the algorithm variables for pipelining or broadcasting. Our proposed design strategy also allows the designer to study time and hardware complexities of computations at each level of the hierarchy. The resultant architecture allows easy modifications to the organization of data buffers and processing elements-their number, datapath pipelining, and complexity-to produce a system whose performance matches the video data sample rate requirements.     

Talbot imaging and unification

The fractional Talbot effect brings into play a superimposition of shifted and complex weightedreplicas of the original object. This phenomenon can be used to replicate images of nonperiodic objects by means of Talbot array illuminators. These diffractive elements can also be used to concentrate replicas into a single image. These techniques are useful for several applications such as beam shaping.     

Stress Intensity Factor Gauging by Digital Image Correlation: Application in Cyclic Fatigue

Abstract:  A fatigue crack in steel (CCT geometry) is studied via digital image correlation. The measurement of the stress intensity factor (SIF) change during one cycle is performed using a decomposition of the displacement field onto a tailored set of elastic fields. The same analysis is performed using two different routes, namely, the first one consists in computing the displacement field using a general correlation technique providing the displacement field projected onto finite element shape functions, and then analysing this displacement field in terms of the selected mechanically relevant fields. The second strategy, called integrated approach, directly estimates the amplitude of these elastic fields from the correlation of successive images. Both procedures give consistent results, and offer very good performances in the evaluation of the crack tip position (uncertainty of about 20  μ m for a 14.5-mm crack), SIFs (uncertainty <1 MPa ) and opening properties.