Hardware/software partitioning of streaming applications for multi-processor system-on-chip

Hardware/software (HW/SW) co-design has emerged as a crucial and integral part in the development of various embedded applications. Moreover, the increases in the number of embedded multimedia and medical applications make streaming throughput an important attribute of Multi-Processor System-on-Chip (MPSoC). As an important development step, HW/SW partitioning affects the system performance. This paper formulates the optimization of HW/SW partitioning aiming at maximizing streaming throughput with predefined area constraint, targeted for multi-processor system with hardware accelerator sharing capability. Software-oriented and hardware-oriented greedy heuristics for HW/SW partitioning are proposed, as well as a branch-and-bound algorithm with best-first search that utilizes greedy results as initial best solution. Several random graphs and two multimedia applications (JPEG encoder and MP3 decoder) are used for performance benchmarking against brute force ground truth. Results show that the proposed greedy algorithms produce fast solutions which achieve 87.7% and 84.2% near-optimal solution respectively compared to ground truth result. With the aid of greedy result as initial solution, the proposed branch-and-bound algorithm is able to produce ground truth solution up to 2.4741e+8 times faster in HW/SW partitioning time compared to exhaustive brute force method

SoC-based biomedical embedded system design of arrhythmia detector

Arrhythmia is an irregular heartbeat where the blood may not be delivered effectively throughout the body and cause sudden cardiac arrest (SCA). Immediate treatment is required to prevent SCA. However, most of the existing electrocardiogram (ECG) monitoring devices are bulky, cost expensive and lack arrhythmia detection and classification system. This paper proposes a front-end on-board graphical interface design of System-on-Chip (SoC) based arrhythmia detector which can be used as a first screening device for cardiac disease patient. The system consists of a knowledge-based arrhythmia classifier which is able to identify three types of arrhythmias which are ventricular fibrillation (VF), premature ventricular contractions (PVCs) and second-degree atrioventricular (AV) block. The system has been evaluated and benchmarked with ECG data from MIT-BIH arrhythmia database. The results show that its accuracy is up to 99.25% with a computation time of 6.385 seconds. It is highly portable and relatively inexpensive for installation in small clinics and home monitoring

Development of platform-independent web-based telecardiology application for pilot case study

Telecardiology is one of the branches from telemedicine that transmits cardiac data such as electrocardiogram (ECG) and medical records from the patient site to cardiologist for the purpose of diagnosis by using telecommunication and information technologies. Most of the current commercialized telecardiology applications are cost expensive, vendor-specific, and dependent on computing platform and operating system (OS). There are plenty of research have been done on web-based telecardiology application either in real-time transmission or store - And-forward. In this paper, a platform-independent and OS-independent web-based telecardiology application, named VirtualDave System, is developed. The proposed system allow users to log on and access from any computer or mobile communication devices such as smart phone as long as they have internet access and web browser. The developed application allows users in categories of patient, administrator, medical officer and cardiologist, to communicate and get medical consultation without long distance traveling. With the improvement to the system dependency and functionality enhancement such as instant messaging, this web-based telecardiology could significantly help to improve the health care services especially in rural area

Application profiling and mapping on NoC-based MPSoC emulation platform on reconfigurable logic

In network-on-chip (NoC) based multi-processor system-on-chip (MPSoC) development, application profiling is one of the most crucial step during design time to search and explore optimal mapping. Conventional mapping exploration methodologies analyse application-specific graphs by estimating its runtime behaviour using analytical or simulation models. However, the former does not replicate the actual application run-time performance while the latter requires significant amount of time for exploration. To map applications on a specific MPSoC platform, the application behaviour on cycle-accurate emulated platform should be considered for obtaining better mapping quality. This paper proposes an application mapping methodology that utilizes a MPSoC prototyped in Field-Programmable Gate Array (FPGA). Applications are implemented on homogeneous MPSoC cores and their costs are analysed and profiled on the platform in term of execution time, intra-core communication and inter-core communication delays. These metrics are utilized in analytical evaluation of the application mapping. The proposed analytical-based mapping is demonstrated against the exhaustive brute force method. Results show that the proposed method is able to produce quality mappings compared to the ground truth solutions but in shorter evaluation time

Ultrahigh sensitivity of slow-light gyroscope

Slow light generated by Electromagnetically Induced Transparency is extremely susceptible with respect to Doppler detuning. Consequently, slow-light gyroscopes should have ultrahigh sensitivity

Efficient immortalization of primary nasopharyngeal epithelial cells for EBV infection study.

Nasopharyngeal carcinoma (NPC) is common among southern Chinese including the ethnic Cantonese population living in Hong Kong. Epstein-Barr virus (EBV) infection is detected in all undifferentiated type of NPC in this endemic region. Establishment of stable and latent EBV infection in premalignant nasopharyngeal epithelial cells is an early event in NPC development and may contribute to its pathogenesis. Immortalized primary nasopharyngeal epithelial cells represent an important tool for investigation of EBV infection and its tumorigenic potential in this special type of epithelial cells. However, the limited availability and small sizes of nasopharyngeal biopsies have seriously restricted the establishment of primary nasopharyngeal epithelial cells for immortalization. A reliable and effective method to immortalize primary nasopharyngeal epithelial cells will provide unrestricted materials for EBV infection studies. An earlier study has reported that Bmi-1 expression could immortalize primary nasopharyngeal epithelial cells. However, its efficiency and actions in immortalization have not been fully characterized. Our studies showed that Bmi-1 expression alone has limited ability to immortalize primary nasopharyngeal epithelial cells and additional events are often required for its immortalization action. We have identified some of the key events associated with the immortalization of primary nasopharyngeal epithelial cells. Efficient immortalization of nasopharyngeal epithelial cells could be reproducibly and efficiently achieved by the combined actions of Bmi-1 expression, activation of telomerase and silencing of p16 gene. Activation of MAPK signaling and gene expression downstream of Bmi-1 were detected in the immortalized nasopharyngeal epithelial cells and may play a role in immortalization. Furthermore, these newly immortalized nasopharyngeal epithelial cells are susceptible to EBV infection and supported a type II latent EBV infection program characteristic of EBV-infected nasopharyngeal carcinoma. The establishment of an efficient method to immortalize primary nasopharyngeal epithelial cells will facilitate the investigation into the role of EBV infection in pathogenesis of nasopharyngeal carcinoma.published_or_final_versio

Relativistic Effects of Light in Moving Media with Extremely Low Group Velocity

A moving dielectric medium acts as an effective gravitational field on light. One can use media with extremely low group velocities [Lene Vestergaard Hau et al., Nature 397, 594 (1999)] to create dielectric analogs of astronomical effects on Earth. In particular, a vortex flow imprints a long-ranging topological effect on incident light and can behave like an optical black hole.Comment: Physical Review Letters (accepted

p21/Cyclin E pathway modulates anticlastogenic function of Bmi-1 in cancer cells.

Apart from regulating stem cell self-renewal, embryonic development and proliferation, Bmi-1 has been recently reported to be critical in the maintenance of genome integrity. In searching for novel mechanisms underlying the anticlastogenic function of Bmi-1, we observed, for the first time, that Bmi-1 positively regulates p21 expression. We extended the finding that Bmi-1 deficiency induced chromosome breaks in multiple cancer cell models. Interestingly, we further demonstrated that knockdown of cyclin E or ectopic overexpression of p21 rescued Bmi-1 deficiency-induced chromosome breaks. We therefore conclude that p21/cyclin E pathway is crucial in modulating the anticlastogenic function of Bmi-1. As it is well established that the overexpression of cyclin E potently induces genome instability and p21 suppresses the function of cyclin E, the novel and important implication from our findings is that Bmi-1 plays an important role in limiting genomic instability in cylin E-overexpressing cancer cells by positive regulation of p21.published_or_final_versio

Light Rays at Optical Black Holes in Moving Media

Light experiences a non-uniformly moving medium as an effective gravitational field, endowed with an effective metric tensor $\tilde{g}^{\mu \nu}=\eta^{\mu \nu}+(n^2-1)u^\mu u^\nu$, $n$ being the refractive index and $u^\mu$ the four-velocity of the medium. Leonhardt and Piwnicki [Phys. Rev. A {\bf 60}, 4301 (1999)] argued that a flowing dielectric fluid of this kind can be used to generate an 'optical black hole'. In the Leonhardt-Piwnicki model, only a vortex flow was considered. It was later pointed out by Visser [Phys. Rev. Lett. {\bf 85}, 5252 (2000)] that in order to form a proper optical black hole containing an event horizon, it becomes necessary to add an inward radial velocity component to the vortex flow. In the present paper we undertake this task: we consider a full spiral flow, consisting of a vortex component plus a radially infalling component. Light propagates in such a dielectric medium in a way similar to that occurring around a rotating black hole. We calculate, and show graphically, the effective potential versus the radial distance from the vortex singularity, and show that the spiral flow can always capture light in both a positive, and a negative, inverse impact parameter interval. The existence of a genuine event horizon is found to depend on the strength of the radial flow, relative to the strength of the azimuthal flow. A limitation of our fluid model is that it is nondispersive.Comment: 30 pages, LaTeX, 4 ps figures. Expanded discussion especially in section 6; 5 new references. Version to appear in Phys. Rev.