1,314 research outputs found
Approximated Computation of Belief Functions for Robust Design Optimization
This paper presents some ideas to reduce the computational cost of
evidence-based robust design optimization. Evidence Theory crystallizes both
the aleatory and epistemic uncertainties in the design parameters, providing
two quantitative measures, Belief and Plausibility, of the credibility of the
computed value of the design budgets. The paper proposes some techniques to
compute an approximation of Belief and Plausibility at a cost that is a
fraction of the one required for an accurate calculation of the two values.
Some simple test cases will show how the proposed techniques scale with the
dimension of the problem. Finally a simple example of spacecraft system design
is presented.Comment: AIAA-2012-1932 14th AIAA Non-Deterministic Approaches Conference.
23-26 April 2012 Sheraton Waikiki, Honolulu, Hawai
Safety verification of asynchronous pushdown systems with shaped stacks
In this paper, we study the program-point reachability problem of concurrent
pushdown systems that communicate via unbounded and unordered message buffers.
Our goal is to relax the common restriction that messages can only be retrieved
by a pushdown process when its stack is empty. We use the notion of partially
commutative context-free grammars to describe a new class of asynchronously
communicating pushdown systems with a mild shape constraint on the stacks for
which the program-point coverability problem remains decidable. Stacks that fit
the shape constraint may reach arbitrary heights; further a process may execute
any communication action (be it process creation, message send or retrieval)
whether or not its stack is empty. This class extends previous computational
models studied in the context of asynchronous programs, and enables the safety
verification of a large class of message passing programs
A Comparison of Petri Net Semantics under the Collective Token Philosophy
In recent years, several semantics for place/transition Petri nets have been proposed that adopt the collective token philosophy. We investigate distinctions and similarities between three such models, namely configuration structures, concurrent transition systems, and (strictly) symmetric (strict) monoidal categories. We use the notion of adjunction to express each connection. We also present a purely logical description of the collective token interpretation of net behaviours in terms of theories and theory morphisms in partial membership equational logic
Asymptotic counting of BPS operators in superconformal field theories
We consider some aspects of counting BPS operators which are annihilated by
two supercharges, in superconformal field theories. For non-zero coupling, the
corresponding multi-variable partition functions can be written in terms of
generating functions for vector partitions or their weighted generalisations.
We derive asymptotics for the density of states for a wide class of such
multi-variable partition functions. We also point out a particular
factorisation property of the finite N partition functions. Finally, we discuss
the concept of a limit curve arising from the large N partition functions,
which is related to the notion of a typical state and discuss some implications
for the holographic duals.Comment: 39 pages latex. v2: minor improvements, reference adde
Tool speed and polarity effects in micro-EDM drilling of 316L stainless steel
This paper focuses on the issues of Resistor-Capacitor-based Electrical Discharge Micro-Machining process and investigates the effects of tool speed and polarity on the performance measures such as Tool Wear Rate, Material Removal Rate, Overcut and Taper Angle by drilling on 316L Stainless Steel. Taguchi’s L54 mixed orthogonal array design is employed to conduct experiments by varying tool polarity at two levels and voltage, capacitance, spindle speed at three levels. The cause and effect relationship between the experimental factors and responses are analysed and discussed using Factorial Analysis of Variance technique. Optimum combinations of machining parameters are also evaluated using Taguchi-based Grey Relational Analysis, by considering grey relational grade matrix and influence of process parameters on the responses. Further, microscopic analysis is done to identify the micro-voids, globular formation, and cracks present on the surface of the hole produced under various machining conditions
Bioanalytical Method Development and Validation: A Review
For various types of drug approval processes like INDs, NDAs, ANDAs, veterinary drug approval, the data related to bioanalytical method development and validation is needed to sponsors. Various agencies namely US FDA, American association of pharmaceutical scientists (AAPS), Health protection Branch (HPB), Association of analytical chemists (AOAC), Center for Veterinary Medicine (CVM), U.S. Department of Health and Human Services Food and drug Administration, Center for Drug Evaluation and Research (CDER), European Medicine Agency (EMA), China Food and Drug administration(CFDA), European Bioanalytical Forum (EBF), Global CRO council (GCC), ANVISA (Brazil), Japan Bioanalytical Forum (JBF) had done collective efforts at different timings to regulate and harmonize bioanalytical method development and validation
An Unusual Foreign Body in the Maxillary Antrum: A Case Report and Pertinent Review of Literature
Maxillary sinus is the largest of the paranasal sinuses and occupies the body of Maxilla. It is pyramidal in shape with base toward lateral wall of nose and apex directed laterally into thezygomatic process. It is roof is formed by the floor of the orbit and grooved by infraorbital nerve. Foreign bodies may present in the paranasal sinuses through a variety of traumatic andiatrogenic events. We describe a case where a sharp foreign body penetrated into the maxillary sinus. We used the open surgical approach, for the removal of sinus foreign body
Aptamers: a novel targeted theranostic platform for pancreatic ductal adenocarcinoma
Pancreatic ductal adenocarcinoma (PDAC) is an extremely challenging disease with a high mortality rate and a short overall survival time. The poor prognosis can be explained by aggressive tumor growth, late diagnosis, and therapy resistance. Consistent efforts have been made focusing on early tumor detection and novel drug development. Various strategies aim at increasing target specificity or local enrichment of chemotherapeutics as well as imaging agents in tumor tissue. Aptamers have the potential to provide early detection and permit anti-cancer therapy with significantly reduced side effects. These molecules are in-vitro selected single-stranded oligonucleotides that form stable three-dimensional structures. They are capable of binding to a variety of molecular targets with high affinity and specificity. Several properties such as high binding affinity, the in vitro chemical process of selection, a variety of chemical modifications of molecular platforms for diverse function, non-immunoreactivity, modification of bioavailability, and manipulation of pharmacokinetics make aptamers attractive targets compared to conventional cell-specific ligands. To explore the potential of aptamers for early diagnosis and targeted therapy of PDAC - as single agents and in combination with radiotherapy - we summarize the generation process of aptamers and their application as biosensors, biomarker detection tools, targeted imaging tracers, and drug-delivery carriers. We are furthermore discussing the current implementation aptamers in clinical trials, their limitations and possible future utilization
The Sentiment Problem: A Critical Survey towards Deconstructing Sentiment Analysis
We conduct an inquiry into the sociotechnical aspects of sentiment analysis
(SA) by critically examining 189 peer-reviewed papers on their applications,
models, and datasets. Our investigation stems from the recognition that SA has
become an integral component of diverse sociotechnical systems, exerting
influence on both social and technical users. By delving into sociological and
technological literature on sentiment, we unveil distinct conceptualizations of
this term in domains such as finance, government, and medicine. Our study
exposes a lack of explicit definitions and frameworks for characterizing
sentiment, resulting in potential challenges and biases. To tackle this issue,
we propose an ethics sheet encompassing critical inquiries to guide
practitioners in ensuring equitable utilization of SA. Our findings underscore
the significance of adopting an interdisciplinary approach to defining
sentiment in SA and offer a pragmatic solution for its implementation.Comment: This paper has been accepted and will appear at the EMNLP 2023 Main
Conferenc
Causality and the AdS Dirichlet problem
The (planar) AdS Dirichlet problem has previously been shown to exhibit
superluminal hydrodynamic sound modes. This problem is defined by bulk
gravitational dynamics with Dirichlet boundary conditions imposed on a rigid
timelike cut-off surface. We undertake a careful examination of this set-up and
argue that, in most cases, the propagation of information between points on the
Dirichlet hypersurface is nevertheless causal with respect to the induced light
cones. In particular, the high-frequency dynamics is causal in this sense.
There are however two exceptions and both involve boundary gravitons whose
propagation is not constrained by the Einstein equations. These occur in i)
AdS, where the boundary gravitons generally do not respect the induced
light cones on the boundary, and ii) Rindler space, where they are related to
the infinite speed of sound in incompressible fluids. We discuss implications
for the fluid/gravity correspondence with rigid Dirichlet boundaries and for
the black hole membrane paradigm.Comment: 29 pages, 5 figures. v2: added refs. v3: minor clarification
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