Generation and evaluation of current and logic tests for switch-level sequential circuits

This article presents an approach to developing high quality tests for switch-level circuits using both current and logic test generation algorithms. Faults that are aborted or undetectable by logic tests may be detected by current tests, or vice versa. An efficient switch level test generation algorithm for generating current and logic tests is introduced. Clear definitions for analyzing the effectiveness of the joint test generation approach are derived. Experimental results are presented for demonstrating high coverage of stuck-at, stuck-on, and stuck-open faults for switch level circuits when both current and logic tests are used.This is expanded version of the work originally presented at the 1991 International Test Conference.     

Priority Aware and Spectrum Efficient Scheduling of Co-existing Wireless Body Area Networks

Real-time continuous and remote health monitoring has become widespread due to the developments in Wireless body area networks (WBANs). Based on the criticality of health data to be transmitted, regular healthcare data and critical emergency health data must be provided differential service. In this paper, we consider the beyond WBAN communication in a system comprising multiple WBANs with different quality of service (QoS) requirements and multiple access points (APs), and propose two hybrid approaches for resource allocation. In the first approach, the AP association to the WBANs and channel allocation to the APs are done jointly and is modelled as an optimization problem, which is computationally complex and it also requires global network information. In order to reduce the involvement of APs in making decisions for resource allocations of WBANs, the problem is reformulated as a Stackelberg game with price update, which guarantees QoS of the critical users. A learning based algorithm, namely distributed learning for Pareto optimality, is used by the normal users, in this second approach. The performance of both the proposed approaches are evaluated and compared, in terms of the throughput of the critical and normal users as well as the QoS guarantee of the critical users.

     

The influence of temperature and humidity on the life-cycle of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

The development of Ephestia kuehniella was followed carefully on white flour at constant temperatures ranging from 7.5° to 31°C at humidities from 0 to 75% r.h. The lower limit of temperature for complete development was about 12°C although a few adults of a stock collected recently emerged at 10°C. Adults emerged at 28 but not at 31°C. Generally, development took longer and survival was poorer at 40 than at 70% r.h. However, at 20 and 25°C survival was good even at 15% r.h., and at 25°C, 18 out of 50 larvae reached the adult stage at a humidity near 0% r.h. Development was fastest at 25°C, 75% r.h., taking a mean of 74 days from oviposition to adult emergence.Oviposition occurred at 7.5 but not at 5°C. Mating was unsuccessful at 12.5°C. Eggs hatched at all temperatures between 12 and 31°C at every r.h. used. A few eggs from two field stocks hatched at 10°C but none did so at 7.5°C.At 12 C no larvae pupated at humidities below 70% r.h., and none pupated at 31°C at any humidity. Larval development was most rapid at 25°C, 75% r.h., taking about 60 days. The shortest mean pupal period, 9 days, occurred at 28°C, 70% r.h. In an experiment with field stocks, many larvae pupated at 10°C but none at 7.5°C.This study confirms E. kuehniella as essentially a temperate species that prefers heated premises such as bakeries and mills for rapid development. Its ability to develop on food at a low e.r.h. fits it further for life in flour mills.     

Simultaneous wireless information and power transfer in heterogeneous cellular networks with underlay D2D communication

Wireless Networks - Device to device (D2D) communication that provides high data rate proximity based direct communication between users, along with simultaneous wireless information and power...     

Carbon Free and Noble Metal Free Ni2Mo6S8 Electrocatalyst for Selective Electrosynthesis of H2O2

Electrocatalytic two-electron reduction of oxygen is a promising method for producing sustainable H₂O₂ but lacks low-cost and selective electrocatalysts. Here, the Chevrel phase chalcogenide Ni₂Mo₆S₈ is presented as a novel active motif for reducing oxygen to H₂O₂ in an aqueous electrolyte. Although it has a low surface area, the Ni₂Mo₆S₈ catalyst exhibits exceptional activity for H₂O₂ synthesis with >90% H₂O₂ molar selectivity across a wide potential range. Chemical titration verified successful generation of H₂O₂ and confirmed rates as high as 90 mmol H₂O₂ g_cat⁻¹ h⁻¹. The outstanding activities are attributed to the ligand and ensemble effects of Ni that promote H₂O dissociation and proton-coupled reduction of O₂ to HOO*, and the spatial effect of the Chevrel phase structure that isolates Ni active sites to inhibit O O cleavage. The synergy of these effects delivers fast and selective production of H₂O₂ with high turn-over frequencies of ≈30 s⁻¹. In addition, the Ni₂Mo₆S₈ catalyst has a stable crystal structure that is resistive for oxidation and delivers good catalyst stability for continuous H₂O₂ production. The described Ni-Mo₆S₈ active motif can unlock new opportunities for designing Earth-abundant electrocatalysts to tune oxygen reduction for practical H₂O₂ production.     

Power consumption of analog circuits: a tutorial

A systematic approach to the power consumption of analog circuits is presented. The power consumption is related to basic circuit requirements, as dynamic range, bandwidth, noise figure and sampling speed and is considering basic device and device scaling behavior. Several kinds of circuits are treated, as samplers, amplifiers, filters and oscillators. The objective is to derive lower bounds to power consumption in analog circuits, to be used as design targets when designing power-constrained analog systems.     

The thermogenic center in social wasps

In the social wasps Vespa orientalis and Paravespula germanica (Hymenoptera, Vespinae), a thermogenic center has been found in the dorsal part of the first thoracic segment. The temperature in this region of the prothorax is higher by 6-9 degrees C than that at the tip of the abdomen, and this in actively flying hornets outside the nest (workers, males or queens) as well as in hornets inside the nest that attend to the brood in the combs. On viewing the region from the outside, one discerns a canal or rather a fissure in the cuticle, which commences at the center of the dorsal surface of the prothorax and extends till the mesothorax. Thus the length of this canal or fissure is approximately 5-7 mm and it is seen to contain numerous thin hairs whose shape varies from that of the hairs alongside the structure. Beneath the cuticle in this region there are dorsoventral as well as longitudinal muscles in abundance, much the same as the musculature in the remaining thoracic segments (i.e. the meso- and metathorax), which activate the two pairs of wings. The canal-bearing segment is of course devoid of wings, and its dorsoventral muscles are attached to the cuticle, which in this region resembles a bowl harboring several layers of epithelium that boasts numerous butterfly-shaped tracheal branches. Additionally there are layers that display lymph-filled spaces and also perforated layers and depressions, and beneath all these is a lace-like layer that also coats the cuticle's hollows. Underneath the cuticle proper, there are numerous large mitochondria and tracheae, which occupy a considerable part of the cuticular epithelium surface. These abundant mitochondria are, most probably, the main element of heat production in the thermogenic center.     

Hornet flight is generated by solar energy: UV irradiation counteracts anaesthetic effects

The Oriental hornet Vespa orientalis (Hymenoptera, Vespinae) flies outside its nest only in the daytime and never in the dark. Oriental hornets can be anaesthetized by means of diethyl ether, following which they awake spontaneously within about > or =1 h. However, when the anaesthetized hornets are exposed to direct irradiation they awake much faster and immediately fly out and this is within the temperature range for their normal activities (20-40 degrees C). Light exerts an effect not only on intact hornets, but also on their main body parts, be they the head, thorax or gaster, or a torso without a head or without a gaster. These body parts also 'awake' from ether anaesthesia when illuminated, especially by ultraviolet (UV) B or shorter light wavelengths, but a body without a gaster awakes much later than normal. As for flight activity, headless hornets do not fly at all, while hornets devoid of a gaster flutter their wings when illuminated but are incapable of rising in the air. When vespan cuticular regions are coated with paint that blocks the passage of light, such as UVB blockers, or with white Tipp-Ex, the awakening from anaesthesia is delayed. The vespan cuticle evinces photovoltaic activity, even in dead specimens, so that upon exposure to light it is possible to record levels of 30-180 mV, both in a wakeful hornet and in one that has undergone anaesthesia. We conjecture that in the awake hornet the voltage that its cuticle generates under the influence of light is transported within the cuticular interlamellar membranes to be utilized as flight energy by the muscles attached to them; however, in the narcotized hornet, the diethyl ether apparently decreases or disrupts membranal order, blocking any ionic channel activity and thereby inducing the anaesthesia. Presumably, this state of phase transition is remedied spontaneously, albeit in a lengthy process, or else the light energy in UV speeds up restoration of the ionic channel activity and the synaptic transmission and thereby contributes to a more rapid awakening. In this regard, the hornet gaster is an extensive region for absorbing light, which explains why its absence considerably delays the awakening from anaesthesia.     

Hide-n-Sense: Preserving Privacy Efficiently in Wireless mHealth

As healthcare in many countries faces an aging population and rising costs, mobile sensing technologies promise a new opportunity. Using mobile health (mHealth) sensing, which uses medical sensors to collect data about the patients, and mobile phones to act as a gateway between sensors and electronic health record systems, caregivers can continuously monitor the patients and deliver better care. Furthermore, individuals can become better engaged in monitoring and managing their own health. Although some work on mHealth sensing has addressed security, achieving strong privacy for low-power sensors remains a challenge. We make three contributions. First, we propose an mHealth sensing protocol that provides strong security and privacy properties at the link layer, with low energy overhead, suitable for low-power sensors. The protocol uses three novel techniques: adaptive security, to dynamically modify transmission overhead; MAC striping, to make forgery difficult even for small-sized Message Authentication Codes; and asymmetric resource requirements, in recognition of the limited resources in tiny mHealth sensors. Second, we demonstrate its feasibility by implementing a prototype on a Chronos wrist device, and evaluating it experimentally. Third, we provide a security, privacy, and energy analysis of our system.