30,084 research outputs found
Automated analysis of oxidative metabolites
An automated system for the study of drug metabolism is described. The system monitors the oxidative metabolites of aromatic amines and of compounds which produce formaldehyde on oxidative dealkylation. It includes color developing compositions suitable for detecting hyroxylated aromatic amines and formaldehyde
Automated analysis of weighted voting games
Weighted voting games (WVGs) are an important mechanism for modeling scenarios where a group of agents must reach agreement on some issue over which they have different preferences. However, for such games to be effective, they must be well designed. Thus, a key concern for a mechanism designer is to structure games so that they have certain desirable properties. In this context, two such properties are PROPER and STRONG. A game is PROPER if for every coalition that is winning, its complement is not. A game is STRONG if for every coalition that is losing, its complement is not. In most cases, a mechanism designer wants games that are both PROPER and STRONG. To this end, we first show that the problem of determining whether a game is PROPER or STRONG is, in general, NP-hard. Then we determine those conditions (that can be evaluated in polynomial time) under which a given WVG is PROPER and those under which it is STRONG. Finally, for the general NP-hard case, we discuss two different approaches for overcoming the complexity: a deterministic approximation scheme and a randomized approximation method
Automated Analysis of MUTEX Algorithms with FASE
In this paper we study the liveness of several MUTEX solutions by
representing them as processes in PAFAS s, a CCS-like process algebra with a
specific operator for modelling non-blocking reading behaviours. Verification
is carried out using the tool FASE, exploiting a correspondence between
violations of the liveness property and a special kind of cycles (called
catastrophic cycles) in some transition system. We also compare our approach
with others in the literature. The aim of this paper is twofold: on the one
hand, we want to demonstrate the applicability of FASE to some concrete,
meaningful examples; on the other hand, we want to study the impact of
introducing non-blocking behaviours in modelling concurrent systems.Comment: In Proceedings GandALF 2011, arXiv:1106.081
Automated analysis of blood pressure measurements (Korotkov sound)
Automatic system for noninvasive measurements of arterial blood pressure is described. System uses Korotkov sound processor logic ratios to identify Korotkov sounds. Schematic diagram of system is provided to show components and method of operation
Automated Analysis of a Nematode Population-based Chemosensory Preference Assay
The nematode, Caenorhabditis elegans' compact nervous system of only 302 neurons underlies a diverse repertoire of behaviors. To facilitate the dissection of the neural circuits underlying these behaviors, the development of robust and reproducible behavioral assays is necessary. Previous C. elegans behavioral studies have used variations of a "drop test", a "chemotaxis assay", and a "retention assay" to investigate the response of C. elegans to soluble compounds. The method described in this article seeks to combine the complementary strengths of the three aforementioned assays. Briefly, a small circle in the middle of each assay plate is divided into four quadrants with the control and experimental solutions alternately placed. After the addition of the worms, the assay plates are loaded into a behavior chamber where microscope cameras record the worms' encounters with the treated regions. Automated video analysis is then performed and a preference index (PI) value for each video is generated. The video acquisition and automated analysis features of this method minimizes the experimenter's involvement and any associated errors. Furthermore, minute amounts of the experimental compound are used per assay and the behavior chamber's multi-camera setup increases experimental throughput. This method is particularly useful for conducting behavioral screens of genetic mutants and novel chemical compounds. However, this method is not appropriate for studying stimulus gradient navigation due to the close proximity of the control and experimental solution regions. It should also not be used when only a small population of worms is available. While suitable for assaying responses only to soluble compounds in its current form, this method can be easily modified to accommodate multimodal sensory interaction and optogenetic studies. This method can also be adapted to assay the chemosensory responses of other nematode species
Automated analysis of security protocols with global state
Security APIs, key servers and protocols that need to keep the status of
transactions, require to maintain a global, non-monotonic state, e.g., in the
form of a database or register. However, most existing automated verification
tools do not support the analysis of such stateful security protocols -
sometimes because of fundamental reasons, such as the encoding of the protocol
as Horn clauses, which are inherently monotonic. A notable exception is the
recent tamarin prover which allows specifying protocols as multiset rewrite
(msr) rules, a formalism expressive enough to encode state. As multiset
rewriting is a "low-level" specification language with no direct support for
concurrent message passing, encoding protocols correctly is a difficult and
error-prone process. We propose a process calculus which is a variant of the
applied pi calculus with constructs for manipulation of a global state by
processes running in parallel. We show that this language can be translated to
msr rules whilst preserving all security properties expressible in a dedicated
first-order logic for security properties. The translation has been implemented
in a prototype tool which uses the tamarin prover as a backend. We apply the
tool to several case studies among which a simplified fragment of PKCS\#11, the
Yubikey security token, and an optimistic contract signing protocol
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