scholarly journals A Logic Framework for P2P Deductive Databases

2019 ◽  
Vol 20 (1) ◽  
pp. 1-43 ◽  
Author(s):  
LUCIANO CAROPRESE ◽  
ESTER ZUMPANO
Keyword(s):  
Logic Program ◽  
Deductive Databases ◽  
Minimal Set ◽  
Weak Model ◽  
Mapping Rules ◽  
System A ◽  
Alternative Characterization ◽  
Different Types ◽  
Declarative Semantics ◽  
P2p System

AbstractThis paper presents a logic framework for modeling the interaction among deductive databases in a peer-to-peer (P2P) environment. Each peer joining a P2P systemprovides or imports datafrom its neighbors by using a set ofmapping rules, that is, a set of semantic correspondences to a set of peers belonging to the same environment. By using mapping rules, as soon as it enters the system, a peer can participate and access all data available in its neighborhood, and through its neighborhood it becomes accessible to all the other peers in the system. A query can be posed to any peer in the system and the answer is computed by using locally stored data and all the information that can be consistently imported from the neighborhood. Two different types of mapping rules are defined: mapping rules allowing to import a maximal set of atoms not leading to inconsistency (calledmaximal mapping rules) and mapping rules allowing to import a minimal set of atoms needed to restore consistency (calledminimal mapping rules). Implicitly, the use of maximal mapping rules statesit is preferable to import as long as no inconsistencies arise; whereas the use of minimal mapping rules states thatit is preferable not to import unless a inconsistency exists. The paper presents three different declarative semantics of a P2P system: (i) theMax Weak Model Semantics, in which mapping rules are used to importas much knowledge as possiblefrom a peer’s neighborhood without violating local integrity constraints; (ii) theMin Weak Model Semantics, in which the P2P system can be locally inconsistent and the information provided by the neighbors is used to restore consistency, that is, to only integrate the missing portion of a correct, but incomplete database; (iii) theMax-Min Weak Model Semanticsthat unifies the previous two different perspectives captured by the Max Weak Model Semantics and Min Weak Model Semantics. This last semantics allows to characterize each peer in the neighborhood as a resource used either to enrich (integrate) or to fix (repair) the knowledge, so as to define a kind ofintegrate–repairstrategy for each peer. For each semantics, the paper also introduces an equivalent and alternative characterization, obtained by rewriting each mapping rule into prioritized rules so as to model a P2P system as a prioritized logic program. Finally, results about the computational complexity of P2P logic queries are investigated by consideringbraveandcautiousreasoning.

Querying and Integrating P2P Deductive Databases

2009 ◽  
pp. 410-416
Author(s):  
Luciano Caroprese ◽  
Sergio Greco ◽  
Ester Zumpano
Keyword(s):  
Query Optimization ◽  
Deductive Databases ◽  
The Other ◽  
Mapping Rules ◽  
System A ◽  
Definition Of ◽  
P2p System

Recently, there have been several proposals that consider the integration of information and the computation of queries in an open-ended network of distributed peers (Bernstein, Giunchiglia, Kementsietsidis, Mylopulos, Serafini, & Zaihrayen, 2002; Calvanese, De Giacomo, Lenzerini, & Rosati, 2004; Franconi, Kuper, Lopatenko, & Zaihrayeu, 2003) as well as the problem of schema mediation and query optimization in P2P (peerto- peer) environments (Gribble, Halevy, Ives, Rodrig, & Suciu, 2001; Halevy, Ives, Suciu, & Tatarinov, 2003; Madhavan & Halevy, 2003; Tatarinov & Halevy, 2004). Generally, peers can both provide or consume data and the only information a peer participating in a P2P system has is about neighbors, that is, information about the peers that are reachable and can provide data of interest. More specifically, each peer joining a P2P system exhibits a set of mapping rules, in other words, a set of semantic correspondences to a set of peers that are already part of the system (neighbors). Thus, in a P2P system, the entry of a new source, or peer, is extremely simple as it just requires the definition of the mapping rules. By using mapping rules as soon as it enters the system, a peer can participate and access all data available in its neighborhood, and through its neighborhood it becomes accessible to all the other peers in the system.

Effectiveness of Truck Rollover Warning Systems

2001 ◽  
Vol 1779 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Derek Baker ◽  
Rob Bushman ◽  
Curtis Berthelot
Keyword(s):  
North America ◽  
Warning System ◽  
Warning Systems ◽  
Commercial Vehicles ◽  
Decision Criteria ◽  
Warning Messages ◽  
System A ◽  
Different Types ◽  
Rollover Warning

Different types of intelligent rollover system deployed by road agencies across North America are investigated. The importance of weight is addressed for maximum effectiveness of rollover warning messages for commercial vehicles in a potential rollover situation on sharp curves or exit ramps. The type of information that may be used to activate a rollover is discussed to analyze the number of correctly warned vehicles compared with the number of false warnings generated by the rollover warning system. A case study of the effectiveness of an intelligent rollover system is presented. On the basis of this case study, it was found that speed-based rollover warning systems generated anywhere from 44 percent to 49 percent more false rollover warnings for commercial vehicles than did rollover warning systems that employed weight information in the rollover decision criteria.

Key principles for the improved conduct of health technology assessments for resource allocation decisions

2008 ◽  
Vol 24 (03) ◽  
pp. 244-258 ◽  
Author(s):  
Michael F. Drummond ◽  
J. Sanford Schwartz ◽  
Bengt Jönsson ◽  
Bryan R. Luce ◽  
Peter J. Neumann ◽  
...  
Keyword(s):  
Resource Allocation ◽  
Health Technology ◽  
Resource Allocation Decision ◽  
Decision Makers ◽  
Costs And Benefits ◽  
Allocation Decision ◽  
Health Technologies ◽  
System A ◽  
Different Types ◽  
Allocation Decisions

Health technology assessment (HTA) is a dynamic, rapidly evolving process, embracing different types of assessments that inform real-world decisions about the value (i.e., benefits, risks, and costs) of new and existing technologies. Historically, most HTA agencies have focused on producing high quality assessment reports that can be used by a range of decision makers. However, increasingly organizations are undertaking or commissioning HTAs to inform a particular resource allocation decision, such as listing a drug on a national or local formulary, defining the range of coverage under insurance plans, or issuing mandatory guidance on the use of health technologies in a particular healthcare system. A set of fifteen principles that can be used in assessing existing or establishing new HTA activities is proposed, providing examples from existing HTA programs. The principal focus is on those HTA activities that are linked to, or include, a particular resource allocation decision. In these HTAs, the consideration of both costs and benefits, in an economic evaluation, is critical. It is also important to consider the link between the HTA and the decision that will follow. The principles are organized into four sections: (i) “Structure” of HTA programs; (ii) “Methods” of HTA; (iii) “Processes for Conduct” of HTA; and (iv) “Use of HTAs in Decision Making.”

The thrust measurement system research for combined nozzle in small space

2018 ◽  
Vol 41 (4) ◽  
pp. 1149-1159
Author(s):  
Yonghua Lu ◽  
Jing Li ◽  
Xiang Zhang ◽  
Yang Li
Keyword(s):  
Measurement System ◽  
Force Sensor ◽  
Test Method ◽  
Small Space ◽  
System A ◽  
Calibration Experiment ◽  
Different Types ◽  
Thrust Measurement ◽  
Nozzle Thrust ◽  
Thrust Forces

For measuring the thrust of combined nozzles in satellite thruster with a small space, the test method that the nozzle directly sprays on the load baffle is employed in this paper. The key problem is how to design the positions of 10 load baffles and how to construct the measurement system. A set of complete and automatic nozzle thrust measurement system is designed and built, and the influence of the load baffle applied on the flow field of nozzles is analyzed using the software FLUENT. Furthermore, the load surface locations of the sensors for the different types of nozzles are analyzed. We draw the conclusion that the load baffle position should range from 4–8 mm for the I-type nozzle and range in 6–12 mm for II-type and III-type nozzle. The correction coefficients of the thrust forces for all channels of the measurement system are determined in the calibration experiment. The uncertainty of measurement system is estimated and the error source of the measurement system is traced. We found that the systematic uncertainty is mainly contributed by the A-type uncertainty which is related with the nozzle dimension and its inner structure. The B-type uncertainty of system is contributed by the force sensor.

Formation of an optimal logistics system based on the analysis of transport infrastructure of the city of Yekaterinburg

Innotrans ◽  
2021 ◽  
pp. 3-7
Author(s):  
Yuliana E. Zhuzhgova ◽  
◽  
Viktoriya V. Savel’eva ◽  
Keyword(s):  
Public Transport ◽  
Transport Infrastructure ◽  
Logistics System ◽  
Passenger Traffic ◽  
Route Network ◽  
System A ◽  
Different Types ◽  
Abc Analysis ◽  
The City ◽  
Constant Growth

The main problems of transport infrastructure of cities are the problems of interaction of different types of transport, optimization of route flows, technical backwardness, low capacity, low speed of travel on public transport, low comfort for passengers. Currently, this is complicated by the constant growth of population and the number of cars, which invariably results in the need for optimization of an urban logistics system. A comprehensive solution to the problems presented can be the building of a network of transport hubs as a new stage in the implementation of transport reform. The article analyzes the transport infrastructure of Yekaterinburg. Based on the ABC analysis of passenger traffic, a method has been developed to identify the stopping points of the route network, which can later be transformed into transport hubs. The optimal logistics system of Yekaterinburg has been formed, consisting of three transport and logistics hubs: “Bus terminal”, “Railway station”, “Professors’” (Professorskaya).

Paving the Way to an Effective and Efficient Retrieval of Data over Semantic Overlay Networks

2010 ◽  
pp. 151-175
Author(s):  
Federica Mandreoli ◽  
Riccardo Martoglia ◽  
Wilma Penzo ◽  
Simona Sassatelli ◽  
Giorgio Villani
Keyword(s):  
Query Processing ◽  
Overlay Networks ◽  
Local Data ◽  
System A ◽  
Processing Strategies ◽  
Efficient Retrieval ◽  
Common Interests ◽  
Routing Mechanism ◽  
Indexing Mechanism ◽  
P2p System

In a Peer-to-Peer (P2P) system, a Semantic Overlay Network (SON) models a network of peers whose connections are influenced by the peers’ content, so that semantically related peers connect with each other. This is very common in P2P communities, where peers share common interests, and a peer can belong to more than one SON, depending on its own interests. Querying such a kind of systems is not an easy task: The retrieval of relevant data can not rely on flooding approaches which forward a query to the overall network. A way of selecting which peers are more likely to provide relevant answers is necessary to support more efficient and effective query processing strategies. This chapter presents a semantic infrastructure for routing queries effectively in a network of SONs. Peers are semantically rich, in that peers’ content is modelled with a schema on their local data, and peers are related each other through semantic mappings defined between their own schemas. A query is routed through the network by means of a sequence of reformulations, according to the semantic mappings encountered in the routing path. As reformulations may lead to semantic approximations, we define a fully distributed indexing mechanism which summarizes the semantics underlying whole subnetworks, in order to be able to locate the semantically best directions to forward a query to. In support of our proposal, we demonstrate through a rich set of experiments that our routing mechanism overtakes algorithms which are usually limited to the only knowledge of the peers directly connected to the querying peer, and that our approach is particularly successful in a SONs scenario.

Optimal Methods of Segmentation of Tomographic Volume Searching System: A Preliminary Review

2016 ◽  
Vol 685 ◽  
pp. 857-862 ◽  
Author(s):  
Igor Skirnevskiy ◽  
Aleksandr Korovin
Keyword(s):  
Computed Tomography ◽  
Image Analysis ◽  
Algorithm Analysis ◽  
Preliminary Review ◽  
Low Contrast ◽  
System A ◽  
Computed Tomography Images ◽  
Implementation Approach ◽  
Wide Range ◽  
Different Types

Recent research studies in the sphere of computer tomography are connected with the task of image analysis. Due to the fact that computed tomography images include artifacts, low contrast and different types of noises, researchers have to deal with a wide range of problems during the processing. There is a wide variety of preliminary processing methods which allow solving these problems. Obviously, the choice of these methods has a major impact on the result [1]. However, algorithm analysis of computed tomography images is not considered in the literature nowadays. This work presents an overview of the implementation approach of these methods.

scholarly journals Cocaine- and Amphetamine-Regulated Transcript (CART ) Peptide in Mammals Gastrointestinal System – A Review

2017 ◽  
Vol 17 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Krystyna Makowska ◽  
Sławomir Gonkowski
Keyword(s):  
Nervous System ◽  
Digestive System ◽  
Gastrointestinal System ◽  
Stress Reactions ◽  
System A ◽  
Cart Peptide ◽  
Different Types ◽  
The Central Nervous System ◽  
The Subject ◽  
Active Substances

Abstract Since its first description over 30 years ago, cocaine- and amphetamine-regulated transcript (CART) peptide has been the subject of many studies. Most of these investigations pertain to occurrence and functions of CART within the central nervous system, where this peptide first of all takes part in regulation of feeding, stress reactions, as well as neuroprotective and neuroregenerative processes. However, in recent years more and more studies concern the presence of CART in the gastrointestinal system. This peptide has been described both in stomach and intestine, as well as in other digestive organs such as pancreas or gallbladder. Particularly much information relates to distribution of CART in the enteric nervous system, which is located within the wall of digestive tract. Other studies have described this peptide in intestinal endocrinal cells. Moreover, it is known that CART can be present in various types of neuronal cells and may co-localize with different types of other neuronal active substances, which play roles of neuromediators and/or neuromodulators. On the other hand precise functions of CART in the gastrointestinal system still remain unknown. It is assumed that this peptide is involved in the regulation of gastrointestinal motility, intestinal blood flow, secretion of intestinal juice, somatostatin and/or insulin, as well as takes part in pathological processes within the gastrointestinal tract. The large number of recent studies concerning the above mentioned problems makes that knowledge about occurrence and functions of CART in the digestive system rather piecemeal and requires clarifying, which is the aim of the present article.

Automated Silverware Sorting Using Vision Based Detection and Recognition Driving Pneumatically Actuated Mechanisms

2012 ◽  
Author(s):  
Ali Asmari ◽  
Lawrence L. Hoberock
Keyword(s):  
Proper Time ◽  
High Volume ◽  
Conveyor Belt ◽  
Pneumatic Actuators ◽  
System A ◽  
Manual Sorting ◽  
Different Types ◽  
Sorting Process ◽  
Design Construction ◽  
Detection And Recognition

Manual Sorting of silverware pieces after being washed by a high-volume commercial dishwasher is a costly and time consuming process which can be improved by automation. This paper describes the design, construction, and testing of an automated silverware sorting process. The process employs machine vision with simple, but effective, high-volume mechanisms to detect the type and orientation of different types of silverware pieces and place them into different bins. The project was conducted in two major phases: 1) Design and Construction of the Mechanism: a simple and effective mechanism was designed to sort the pieces into separate bins off of a conveyor belt. Pneumatic actuators provided the key mechanical sorting. 2) Design of the Control System: a computer program was developed that detects the entrance of a piece into the machine and recognizes the type and orientation of each silverware piece using computer vision techniques. The software then commands the proper mechanical component at the proper time to actuate, so that each piece ends up in the designated bin. The machine was tested with different silverware input sequences The accuracy of the software in identifying the type and direction of the pieces, the accuracy of the mechanical system in sorting the pieces, and the accuracy of the overall system were found to be 100%, 90.63% and 88.75% respectively.

scholarly journals Multivaluedness in Networks: Exemplars

2020 ◽  
Author(s):  
Anton van Wyk ◽  
Guanrong Chen ◽  
Eric W. M. Wong
Keyword(s):  
Dynamical System ◽  
Random Process ◽  
Nonlinear Dynamical System ◽  
Linear Estimator ◽  
Nonlinear Dynamical ◽  
System A ◽  
Input And Output ◽  
Different Types ◽  
The Impact

This brief presents the first observations of multivaluedness in four systems: a random process, a nonlinear nondynamical system, a nonlinear dynamical system with nonlinearly sensed input and output and an adaptive linear estimator. The preliminary findings reported here, suggest the impact of multivaluedness in different types of networks to range from adverse to benign or even essential.

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