3,357 research outputs found
Trends in Cardiac Pacemaker Batteries
Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future
Method of characteristics and solution of DGLAP evolution equation in leading order (LO) and next to leading order (NLO) at small-x
In this paper the singlet and non-singlet structure functions have been
obtained by solving Dokshitzer, Gribove, Lipatov, Alterelli, Parisi (DGLAP)
evolution equations in leading order (LO) and next to leading order (NLO) at
the small x limit. Here we have used a Taylor Series expansion and then the
method of characteristics to solve the evolution equations. We have also
calculated t and x-evolutions of deuteron structure function and the results
are compared with the New Muon Collaboration (NMC) data.Comment: 16 pages including 7 figure
Isomorphism testing of read-once functions and polynomials
In this paper, we study the isomorphism testing problem of formulas in
the Boolean and arithmetic settings. We show that isomorphism testing
of Boolean formulas in which a variable is read at most once (known as
read-once formulas) is complete for log-space. In contrast, we observe
that the problem becomes polynomial time equivalent to the graph
isomorphism problem, when the input formulas can be represented as OR
of two or more monotone read-once formulas. This classifies the
complexity of the problem in terms of the number of reads, as read-3
formula isomorphism problem is hard for coNP.
We address the polynomial isomorphism problem, a special case of
polynomial equivalence problem which in turn is important from a
cryptographic perspective[Patarin EUROCRYPT\u2796, and Kayal SODA\u2711]. As our main result, we propose a deterministic polynomial time
canonization scheme for polynomials computed by constant-free
read-once arithmetic formulas. In contrast, we show that when the
arithmetic formula is allowed to read a variable twice, this problem
is as hard as the graph isomorphism problem
Guided Missile with an Intelligent Agent
Guided missiles involve the use of a conventional deviated pursuit course like proportionalnavigation algorithm and its variants, which is optimal when the speed advantage of the guided missile is veryhighandthe target maneouvering is minimal. Against the present-day aircraft,whichemploys fly-by-wire technology for high maneouverability andhigh speed, missiles needto have amuchhigher speed advantage or to use a combination of artificial intelligence and modern controlalgorithms. Results of simulation of pursuit and evasion with an autonomous intelligent agentincorporated in the control loop are presented
Data Compression to combat tracking issues in RADAR Sensor scenario: An on going case study
In general , high data transfer rate of RADAR emitter would be a challenge for slow tracking devices. One of the solution to such problems, is adresssed in this paper. Data compression, by differential encoding technique facilitates to implement on available devices with less performance levels
Mixed Mucinous Carcinoma of the Male Breast
Male breast malignancy is extremely rare, representing less than 1% of all breast carcinomas. Infiltrating duct carcinoma is the commonest subtype. Pure mucinous carcinoma and mixed mucinous carcinoma wherein there are components of both mucinous carcinoma and infiltrating duct carcinoma are rare tumours constituting 1.5-5% in women and are even rarer in men. We present here a case of mixed mucinous carcinoma of the breast with metastasis to axillary lymph nodes in a male patient
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