Jeong-A Lee

A Design Method for Heterogeneous Adders

The performance of existing adders varies widely in their speed and area requirements, which in turn sometimes makes designers pay a high cost in area especially when the delay requirements exceeds the fastest speed of a specific adder, no matter how small the difference is. To expand the design space and manage delay/area tradeoffs, we propose new adder architecture and a design methodology. The proposed adder architecture, named heterogeneous adder, decomposes an adder into blocks (sub-adders) consisting of carry-propagate adders of different types and precision. The flexibility in selecting the characteristics of sub-adders is the basis in achieving adder designs with desirable characteristics. We consider the area optimization under delay constraints and the delay optimization under area constraints by determining the bit-width of sub-adders using Integer Linear Programming. We demonstrate the effectiveness of the proposed architecture and the design method on 128-bit operands.

SMiRA: A bio-inspired fault tolerant routing algorithm for MANETs

Spiral Millipede-inspired Routing Algorithm (SMiRA) is presented as a bio-inspired approach for routing in MANETs. It has been designed as a resource light technique that reduces routing overhead and improves the level of tolerance to routing faults, amongst other things. It has been compared to the Ad-hoc On-demand Distance Vector (AODV). The results show an improvement in the monitored metrics, with a limited penalty. SMiRA has an average of 40.77% reduction is routing overhead and an average of 41.85% reduction in fault-tolerance latency, with an average of 3.118 s increase in node computational latency as the main penalty for an extremely resource limited Mica mote.

Medical Virtual Instrumentation for Ambient Assisted Living: Part 1 Concepts

Ambient Assisted Living has become a cost-effective option for coping with the rapid aging of society. Personalized health monitoring is an important aspect of Ambient Assisted Living, and it depends on the availability and use of appropriate medical devices. Medical virtual instruments provide a viable option for such devices. They refer to a hardware/software co-design of medical instruments that provides the dependability of hardware as well as the flexibility of software. In this paper, we discuss the concept of medical virtual instruments and their use as an effective option for Ambient Assisted Living. The discussion covers the enablers of this technology, the main challenges, and the hardware, software and connectivity options for such instruments.

Medical Virtual Instrumentation for Personalized Health Monitoring: A Systematic Review.

The rising cost of healthcare and the increased senior population are some reasons for the growing adoption of the Personalized Health Monitoring (PHM) systems. Medical Virtual Instruments (MVIs) provide portable, flexible, and low-cost options for these systems. Our systematic literature search covered the Cochrane Library, Web of Science, and MEDLINE databases, resulting in 915 articles, and 25 of which were selected for inclusion after a detailed screening process that involved five stages. The review sought to understand the key aspects regarding the use of MVIs for PHM, and we identified the main disease domains, sensors, platforms, algorithms, and communication protocols for such systems. We also identified the key challenges affecting the level of integration of MVIs into the global healthcare framework. The review shows that MVIs provide a good opportunity for the development of low cost personalized health systems that meet the unique instrumentation requirements for a given medical domain.

SAFE-points: a lightweight algorithm for analyzing remote mobile ECG signals

In this paper, we present our Select All Fiducially Essential points (SAFE-points) algorithm that uses ECG signal images as an approach for achieving highly efficient ECG signal analysis within a mobile environment at a fraction of the associated costs in terms of latency, memory and goodput. We were able to achieve latency, memory and goodput values of about 17%, 25% and 25% respectively when compared with our reference.

An on-node intelligence based energy efficient ECG monitoring system

This paper proposes a two-tier body sensor network architecture for electrocardiogram (ECG) monitoring which consists of a base station layer and a sensor nodes layer with an intelligent ECG analysis function achieved by employing a simple but effective classification method. In this scenario, a sensor node only transmits sensed data to a base station when the sensed data shows abnormality. Such an approach is energy-efficient, while ensuring that abnormal ECG cycles are never missed. For the low power implementation of the abnormality detection on a local power-hungry sensor node, we propose a light-weight computation of the Euclidean distance between a sensed ECG signal and a reference ECG signal. Using experimental results obtained on PowerTOSSIM, we demonstrate that our approach can reduce power consumption of the sensor nodes by 39–57% and, accordingly, prolong the lifetime of the whole monitoring system.

Thermal Analysis for 3D Multi-core Processors with Dynamic Frequency Scaling

As the process technology scales down, interconnects become the performance bottleneck when designing multi-core processors. 3D IC can be a good solution for reducing the interconnection delay in the multi-core processors by stacking multiple layers connected through TSVs. However, 3D technology magnifies the thermal challenges in 3D multi-core processors. For this reason, 3D multi-core architecture cannot be practical without proper solutions to the thermal problems such as efficient DFS. This paper investigates how the continuous engaged DFS technique handles the thermal problem on 3D multi-core processors in unit level. We also identify the optimal matrix to achieve best performance varying application features, cooling characteristics, and frequency levels when the thermal problem is considered. Experimental results conclude two rules for managing and balancing the temperature of the die, especially the IntReg unit: 1) To optimize the thermal profile of both dies, the die with higher cooling efficiency should be clocked at a higher frequency; and 2) To lower the temperature of IntReg unit, workload with higher thermal impact should be assigned to cores with higher cooling efficiency.

Medical Virtual Instrumentation for Ambient Assisted Living: Part 2 Practice and Case Studies:

In this article, we discuss how medical virtual instruments are used for ambient assisted living technologies. Ambient assisted living technologies enable seniors to age well in the comfort of their homes. Case studies are used to describe some ways that medical virtual instruments are being used to support ambient assisted living in the key disease domains of cardiovascular, neurologic, hormonal and musculoskeletal health. The article also discusses the open research issues and future perspectives relating to the use of medical virtual instruments in these domains.

Accurate and Energy Efficient ECG Analysis Method for ECG Monitoring System

This paper proposes an energy efficient ECG monitoring system by putting some intelligence on the sensor node to reduce the number of transmissions. The sensor node is mostly put into the processing mode and just connects the base station when necessary. Therefore, the transmission energy is greatly reduced while the energy for processing is increased a little bit. Our proposed ECG analysis method classifies ECG cycles by computing the Euclidean distance between the sensed ECG cycle and the reference ECG cycle. This work is a detailed and full explanation of our former work. Extended experimental results show that the proposed trade is very effective in saving energy and the Euclidean distance based classification method is accurate. Furthermore, the PowerTOSSIM energy simulation method is also demonstrated as very accurate in evaluating the energy consumption of the sensor node in our application scenario.