Error modeling and performance analysis of error-correcting codes for the digital video recording system

We describe the format of the 22.5 GB rewritable digital-video-recording (DVR) system. The format is based on an objective lens with a high numerical aperture (NA=0.85), a thin cover layer (0.100 mm thick), and a blue-laser diode (λ=405 nm). We discuss experimental verification of the format and possible future extensions. The DVR system is well suited to be the basis of a third-generation optical-recording family for high-definition video recording.

Communication during trauma resuscitation: do we know what is happening?

With the advent of multicore processors, the performance of software has been elevated to new unforeseen heights via parallelization. However, this has not been achieved without new problems cropping up due to parallelization. One serious issue is the performance bottleneck due to cache misses or resource starvation, which is hard to detect in application software especially when the software has dynamically changing behavior. Performance monitors are usually employed for such purposes. Nevertheless, monitors have introduced their own computation and communication overheads, especially in embedded multicore systems. In this work, we try to estimate the effects of monitor overheads on different types of applications, such as CPU-bound and IO-bound tasks. Further, we give suggestions on the number and type of monitors to use for such embedded multicore applications. Besides trying to reduce monitor overheads, we also aim for the accuracy and the immediacy of the monitored information. Through a real-world example, namely digital video recording system, we demonstrate how different monitoring periods affect the tradeoff between accuracy and immediacy of the monitored information.

To understand how people really interact with digital TV and digital video recorder (DVR) systems, 10 people were recruited, 6 with DVRs and 4 with non-DVR digital cable or satellite TV systems. Video-recording equipment was set up in their homes to record their TV viewing. The person viewing as well as the TV content being viewed were recorded as the person watched TV. Afterwards, the recordings were reviewed and analyzed by the experimenter together with the viewer, who then described his or her behavior. The results show that overall the most common way people interacted with TV was in avoiding advertisements and finding new programming to watch when the current show ended. These results can be used to find ways to improve how users experience TV systems.

Preliminary clinical study of the accuracy of a digital axiographic recording system for the assessment of sagittal condylar inclination

An optical disc is a multilayered medium consisting of a thick glass substrate on which many layers of different materials are sputtered. Only one of these layers serves as a recording medium and it is initially magnetized uniformly in one direction. To write on this disc, the initial magnetic field is altered by focusing light from a laser source with high numerical aperture (NA) lens to heat the magnetic medium beyond its Curie point, the temperature at which the magnetic medium loses its magnetization. This domain with zero magnetization is subsequently magnetized in the reversed direction by using an induction magnet. All these processes take place while the disc is rotating at a very high speed with respect to the laser. It is well known that partial obscuration reduces the spot size and the depth of focus; and in the present case of optical recording both are highly desirable. Significant improvement in data densities and quality of the written spot is achieved by writing with an obscured pupil as shown here. In this paper, we examine optical imaging and transient heat transfer problems to study the writing process. The vector diffraction theory is employed to calculate energy distribution on the disc surface and then this energy distribution is used as a source for the heat transfer problem. Writing with lenses of various NA is examined and various optical effects such as "fill factors" and obscuration, mechanical effects such as the thermal properties of the disc material, and writing conditions are considered. Results pertinent to the design of the disc medium, the optical elements, the mechanical components, and the development of the write algorithm are discussed. The quality of the written spots and the resulting data densities during a typical write sequence is discussed.

Nowadays, security of valuable and secret assets is very important for large organization. Need of an efficient and reliable security system arises due to limitation of human resources and manpower. In such systems, video surveillance systems have their own significance. Although some people don’t like the idea of being monitored, surveillance systems improve the public security, allowing the system to detect dangers. Multimedia data typically means digital imagesaudio, video, animation and graphics together with text data. The acquisition, generation, storage and processing of multimedia data in computers and transmission over networks have grown tremendously in the recent past. In video surveillance, motion detection refers to the capability of the surveillance system to detect motion, identify the activity and capture the events while preventing the negligible activities. Motion detection is usually a software-based monitoring algorithm which, when it detects motions will signal the surveillance camera to begin capturing the event. Also called activity detection. An advanced motion detection surveillance system can analyze the type of motion to see if it warrants an alarm. In this research, we propose a novel motion detection algorithm for digital video recording (DVR) system using a Fuzzy Rule Based System that detects the motion in the running video intelligently.

Nowadays, chip multi-processors (CMP) are being widely used in embedded systems due to their superior performance for parallel computing. However, they also incur significantly large power consumption. To solve this issue, designers of embedded operating system must provide an efficient thread scheduling algorithm, which not only maximizes the system performance, but also minimizes the energy consumption. Further, if the scheduler makes decisions without considering the precedence relationships among threads, the decisions could conflict with the thread behavior which could result in poor performance and large energy consumption. In this paper, we propose a synchronization-aware dynamic thread scheduling algorithm (SA), which reduces the busy-waiting time caused by spinlock, and with performance improvement and energy saving. SA has two major objectives, including (1) overall high performance, in terms of less completion time and less turnaround time, and (2) low energy consumption for all threads. The experimental results show that SA indeed improves performance and reduces energy consumption compared to the original scheduling algorithm of Linux kernel version 2.6. In a real-world case, the Digital Video Recording (DVR) system, SA achieves performance speedup by at most 1.21 and saves the energy consumption by at most 28.6%.

With the advance of digital video recording and playback systems, the request for efficiently managing recorded TV video programs is evident so that users can readily locate and browse their favorite programs. In this paper, we propose a multimodal scheme to segment and represent TV video streams. The scheme aims to recover the temporal and structural characteristics of TV programs with visual, auditory, and textual information. In terms of visual cues, we develop a novel concept named program-oriented informative images (POIM) to identify the candidate points correlated with the boundaries of individual programs. For audio cues, a multiscale Kullback-Leibler (K-L) distance is proposed to locate audio scene changes (ASC), and accordingly ASC is aligned with video scene changes to represent candidate boundaries of programs. In addition, latent semantic analysis (LSA) is adopted to calculate the textual content similarity (TCS) between shots to model the inter-program similarity and intra-program dissimilarity in terms of speech content. Finally, we fuse the multimodal features of POIM, ASC, and TCS to detect the boundaries of programs including individual commercials (spots). Towards effective program guide and attracting content browsing, we propose a multimodal representation of individual programs by using POIM images, key frames, and textual keywords in a summarization manner. Extensive experiments are carried out over an open benchmarking dataset TRECVID 2005 corpus and promising results have been achieved. Compared with the electronic program guide (EPG), our solution provides a more generic approach to determine the exact boundaries of diverse TV programs even including dramatic spots.

This chapter demonstrates how high-level code is automatically generated for multi-core processors. The code generation capability of the Verifiable Embedded Real-Time Application Framework (VERTAF) was extended to support multi-core processors in the new VERTAF/Multi-Core (VMC) framework for embedded systems. After users specify embedded software requirements via SysML models along with parallel task, parallel data, and parallel dataflow specifications, the code generator automatically generates parallel code. Using the digital video recording (DVR) system as a case study, we show the correctness and advantages of the VMC code generator. The main inputs of VMC code generator include the block definition diagrams, state machine diagrams, and requirement diagrams of the system to be designed. The proposed code generation in VMC not only significantly decreases the amount of manually-written code, but also provides a formal procedure for model-conforming code generation of multi-core embedded software.

A high numerical aperture (NA) lens is used in many applications that require tightly focused beams including microscopy. The Debye-Wolf electromagnetic diffraction integral describes focusing by high NA lenses. Using an eigenfunction expansion of this integral, we numerically obtain a pupil mask that generates an arbitrary, within the diffraction limit, intensity distribution at the Gaussian focal plane.

Signals are acquired from medical instrumentation of many different types. They can be as small as a digital thermometer or as big as a magnetic resonance scanner. In spite of the differences in size, cost, and the type of data these devices obtain, most biomedical devices that acquire physiologic data have the same basic structure. The structure of what we will call the basic digital physiologic recording system will be described in this section with the details of each of the processes in the following sections. A block diagram of the basic digital physiologic recording system is shown in Fig. 1.1.

A real-time digital seismic event detection and recording system has been developed for the MIT Seismic Network. The system has been designed specifically for an environment of low natural seismic activity and for surface stations which are often influenced by weather conditions and cultural noise. The system runs on an HP-1000 computer and can handle up to 16 channels of short- and long-period data. The structure of the system centers around the event detectors, one for short-period data and one for long-period data. These detectors base their decisions on a metric computed from the Walsh transform of the data. This allows them to detect changes in the amplitude of the waveform as well as frequency shifts. Detections at several stations are correlated to prevent glitches from triggering the detector. Present operation successfully saves those events that are large enough for analysis and leaves 23 of the computer available for general timesharing use.

The paper describes an improved digital recorder system which is being used to provide reference values of voltage, current, active, reactive and apparent powers and harmonic quantities for three-phase sinusoidal and nonsinusoidal calibrations. The system has been designed to be used in the laboratory at the National Research Council of Canada (NRC) or transported on-site for tests in electrical utility facilities. Test results have shown that for sinusoidal waveforms, the accuracy of the voltage and current measurements of the digital recorder is better than 25 /spl mu/V/V or /spl mu/A/A of full scale and better than 50 /spl mu/W/W of full scale for active and apparent power measurements. The accuracy of the system for measurements under the seven distorted waveforms conditions most commonly used at NRC is better than 50 /spl mu/V/V or /spl mu/A/A of full scale for voltage and current measurements and better than 100 /spl mu/W/W or /spl mu/VA/VA of full scale for active and apparent power measurements.

Micro lens array is crucial in various kinds of optical and electronic applications. A micro lens array with high numerical aperture (NA) and low aberration is in particular needed. This research is aimed to design and fabricate such a micro lens array with simple structure while keeps the same NA of a same-diameter hemisphere lens. A bi-convex semispherical micro lens array, with corresponding NA 0.379, by PDMS is first designed and analyzed. Experiments are further conducted to fabricate the designed micro lens array by the thermal reflow process. The formed profile is then sputtered with copper to serve as the mold. The front and the rear micro lens array are fabricated by plating PDMS to the mold and then assembled to form the designed micro lens array.