pinecone/core-2020-05-10-deduplication huggingface dataset:
A trigger-based middleware cache for ORMs

Caching is an important technique in scaling storage for high-traffic web applications. Usually, building caching mechanisms involves significant effort from the application developer to maintain and invalidate data in the cache. In this work we present CacheGenie, a caching middleware which makes it easy for web application developers to use caching mechanisms in their applications. CacheGenie provides high-level caching abstractions for common query patterns in web applications based on Object-RelationalMapping (ORM) frameworks. Using these abstractions, the developer does not have to worry about managing the cache (e.g., insertion and deletion) or maintaining consistency (e.g., invalidation or updates) when writing application code.
We design and implement CacheGenie in the popular Django web application framework, with PostgreSQL as the database backend and memcached as the caching layer. To automatically invalidate or update cached data, we use triggers inside the database. CacheGenie requires no modifications to PostgreSQL or memcached. To evaluate our prototype, we port several Pinax web applications to use our caching abstractions. Our results show that it takes little effort for application developers to use CacheGenie, and that CacheGenie improves throughput by 2-2.5× for read-mostly workloads in Pinax.ACM/IFIP/USENIX 12th International Middleware Conference, Lisbon, Portugal, December 12-16, 2011. ProceedingsQuanta Computer (Firm
A middleware layer for flexible and cost-efficient multi-tenant applications

Application-level multi-tenancy is an architectural design principle for Software-as-a-Service applications to enable the hosting of multiple customers (or tenants) by a single application instance. Despite the operational cost and maintenance benefits of application-level multi-tenancy, the current middleware component models for multi-tenant application design are inflexible with respect to providing different software variations to different customers.

In this paper we show that this limitation can be solved by a multi-tenancy support layer that combines dependency injection with middleware support for tenant data isolation. Dependency injection enables injecting different software variations on a per tenant basis, while dedicated middleware support facilitates the separation of data and configuration metadata between tenants. We implemented a prototype on top of Google App Engine and we evaluated by means of a case study that the improved flexibility of our approach has little impact on operational costs and upfront application engineering costs.status: publishe
SafeWeb: a Middleware for securing Ruby-based web applications

Web applications in many domains such as healthcare and finance must process sensitive data, while complying with legal policies regarding the release of different classes of data to different parties. Currently, software bugs may lead to irreversible disclosure of confidential data in multi-tier web applications. An open challenge is how developers can guarantee these web applications only ever release sensitive data to authorised users without costly, recurring security audits.\ud
Our solution is to provide a trusted middleware that acts as a “safety net” to event-based enterprise web applications by preventing harmful data disclosure before it happens. We describe the design and implementation of SafeWeb, a Ruby-based middleware that associates data with security labels and transparently tracks their propagation at different granularities across a multi-tier web architecture with storage and complex event processing. For efficiency, maintainability and ease-of-use, SafeWeb exploits the dynamic features of the Ruby programming lan- guage to achieve label propagation and data flow enforcement. We evaluate SafeWeb by reporting our experience of implementing a web-based cancer treatment application and deploying it as part of the UK National Health Service (NHS)
Bagging ensemble selection

Ensemble selection has recently appeared as a popular ensemble learning method, not only because its implementation is fairly straightforward, but also due to its excellent predictive performance on practical problems. The method has been highlighted in winning solutions of many data mining competitions, such as the Netix competition, the KDD Cup 2009 and 2010, the UCSD FICO contest 2010, and a number of data mining competitions on the Kaggle platform. In this paper we present a novel variant: bagging ensemble selection. Three variations of the proposed algorithm are compared to the original ensemble selection algorithm and other ensemble algorithms. Experiments with ten real world problems from diverse domains demonstrate the benefit of the bagging ensemble selection algorithm
Augmented Spatial Pooling

It is a widely held view in contemporary computational neuroscience that the brain responds to sensory input by producing sparse distributed representations. In this paper we investigate a brain-inspired spatial pooling algorithm that produces such sparse distributed representations by modelling the formation of proximal dendrites associated with neocortical minicolumns. In this approach, distributed representations are formed out of a competitive process of inter-column inhibition and subsequent learning. Specifically, we evaluate the performance of a recently proposed binary spatial pooling algorithm on a well-known benchmark of greyscale natural images. Our main contribution is to augment the algorithm to handle greyscale images, and to produce better quality encodings of binary images. We also show that the augmented algorithm produces superior population and lifetime kurtosis measures in comparison to a number of other well-known coding schemes.Griffith Sciences, School of Information and Communication TechnologyFull Tex
A simple strategy to maintain diversity and reduce crowding in particle swarm optimization

Each particle in a swarm maintains its current position and its personal best position. It is useful to think of these personal best positions as a population of attractors -- updates to current positions are based on attractions to these personal best positions. If the population of attractors has high diversity, it will encourage a broad exploration of the search space with particles being drawn in many different directions. However, the population of attractors can
converge quickly -- attractors can draw other particles towards them, and these particles can update their own personal bests to be near the first attractor. This convergence of attractors can be reduced by having a particle update the attractor it has approached rather than its own attractor/personal best. This simple change to the update procedure in particle swarm optimization incurs minimal computational cost, and it can lead to large performance improvements in multi-modal search spaces
Semi-supervised classification using tree-based self-organizing maps

Published version of an article from the following onference prodeedings: AI 2011: Advances in Artificial Intelligence. Also available from the publisher on SpringerLink: http://dx.doi.org/10.1007/978-3-642-25832-9_3This paper presents a classifier which uses a tree-based Neural Network (NN), and uses both, unlabeled and labeled instances. First, we learn the structure of the data distribution in an unsupervised manner. After convergence, and once labeled data become available, our strategy tags each of the clusters according to the evidence provided by the instances. Unlike other neighborhood-based schemes, our classifier uses only a small set of representatives whose cardinality can be much smaller than that of the input set. Our experiments show that, on average, the accuracy of such classifier is reasonably comparable to those obtained by some of the state-of-the-art classification schemes that only use labeled instances during the training phase. The experiments also show that improved levels of accuracy can be obtained by imposing trees with a larger number of nodes
A Defeasible Logic for Clauses

Abstract. A new non-monotonic logic called clausal defeasible logic (CDL) is defined and explained. CDL is the latest in the family of defeasible logics, which, it is argued, is important for knowledge representation and reasoning. CDL increases the expressive power of defeasible logic by allowing clauses where previous defeasible logics only allowed literals. This greater expressiveness allows the representation of the Lottery Paradox, for example. CDL is well-defined, consistent, and has other desirable properties.Griffith Sciences, School of Information and Communication TechnologyFull Tex
Tracking the preferences of users using weak estimators

Published version of am article from the book:AI 2011: Advances in Artificial Intelligence. Also available from the publisher on SpringerLink:http://dx.doi.org/10.1007/978-3-642-25832-9_81Since a social network, by definition, is so diverse, the problem of estimating the preferences of its users is becoming increasingly essential for personalized applications which range from service recommender systems to the targeted advertising of services. However, unlike traditional estimation problems where the underlying target distribution is stationary, estimating a user’s interests, typically, involves non-stationary distributions. The consequent time varying nature of the distribution to be tracked imposes stringent constraints on the “ unlearning ” capabilities of the estimator used. Therefore, resorting to strong estimators that converge with probability 1 is inefficient since they rely on the assumption that the distribution of the user’s preferences is stationary. In this vein, we propose to use a family of stochastic-learning based Weak estimators for learning and tracking user’s time varying interests. Experimental results demonstrate that our proposed paradigm outperforms some of the traditional legacy approaches that represent the state-of-the-art
Ontology-Based Access Rights Management

International audienceIn this paper we propose an approach to manage access rights in a content management systems which relies on semantic web models and technologies. We present the AMO ontology which consists (1) in a set of classes and properties dedicated to the annotation of resources whose access should be controlled and (2) in a base of inference rules modeling the access management strategy to carry out. When applied to the annotations of the resources whose access should be controlled, these rules enable to manage access according to a given strategy. This modelisation is flexible, extendable and ensures the adaptability of the AMO ontology to any access management strategy. We illustrate the use of AMO on the documents of a collaborative website managed by the semantic wiki SweetWiki in the ANR ISICIL project. We show how to annotate documents with AMO, we explain which AMO inference rules can be applied and which semantic queries finally enable to control access to SweetWiki documents
Complexity of Splits Reconstruction for Low-Degree Trees

Given a vertex-weighted tree T, the split of an edge xy in T is min{s_x(xy),
s_y(xy)} where s_u(uv) is the sum of all weights of vertices that are closer to
u than to v in T. Given a set of weighted vertices V and a multiset of splits
S, we consider the problem of constructing a tree on V whose splits correspond
to S. The problem is known to be NP-complete, even when all vertices have unit
weight and the maximum vertex degree of T is required to be no more than 4. We
show that the problem is strongly NP-complete when T is required to be a path,
the problem is NP-complete when all vertices have unit weight and the maximum
degree of T is required to be no more than 3, and it remains NP-complete when
all vertices have unit weight and T is required to be a caterpillar with
unbounded hair length and maximum degree at most 3. We also design polynomial
time algorithms for the variant where T is required to be a path and the number
of distinct vertex weights is constant, and the variant where all vertices have
unit weight and T has a constant number of leaves. The latter algorithm is not
only polynomial when the number of leaves, k, is a constant, but also
fixed-parameter tractable when parameterized by k. Finally, we shortly discuss
the problem when the vertex weights are not given but can be freely chosen by
an algorithm.
  The considered problem is related to building libraries of chemical compounds
used for drug design and discovery. In these inverse problems, the goal is to
generate chemical compounds having desired structural properties, as there is a
strong correlation between structural properties, such as the Wiener index,
which is closely connected to the considered problem, and biological activity
Online regenerator placement.

Connections between nodes in optical networks are realized by lightpaths. Due to the decay of the signal, a regenerator has to be placed on every lightpath after at most d hops, for some given positive integer d. A regenerator can serve only one lightpath. The placement of regenerators has become an active area of research during recent years, and various optimization problems have been studied. The first such problem is the Regeneration Location Problem (Rlp), where the goal is to place the regenerators so as to minimize the total number of nodes containing them. We consider two extreme cases of online Rlp regarding the value of d and the number k of regenerators that can be used in any single node. (1) d is arbitrary and k unbounded. In this case a feasible solution always exists. We show an O(log|X| ·logd)-competitive randomized algorithm for any network topology, where X is the set of paths of length d. The algorithm can be made deterministic in some cases. We show a deterministic lower bound of W([(log(|E|/d) ·logd)/(log(log(|E|/d) ·logd))])log(Ed)logdlog(log(Ed)logd) , where E is the edge set. (2) d = 2 and k = 1. In this case there is not necessarily a solution for a given input. We distinguish between feasible inputs (for which there is a solution) and infeasible ones. In the latter case, the objective is to satisfy the maximum number of lightpaths. For a path topology we show a lower bound of Öl/2l2  for the competitive ratio (where l is the number of internal nodes of the longest lightpath) on infeasible inputs, and a tight bound of 3 for the competitive ratio on feasible inputs. \u
On the nature of progress

We identify a simple relationship that unifies seemingly unrelated progress conditions ranging from the deadlock-free and starvation-free properties common to lock-based systems, to non-blocking conditions such as obstruction-freedom, lock-freedom, and wait-freedom.
Properties can be classified along two dimensions based on the demands they make on the operating system scheduler. A gap in the classification reveals a new non-blocking progress condition, weaker than obstruction-freedom, which we call clash-freedom.
The classification provides an intuitively-appealing explanation why programmers continue to devise data structures that mix both blocking and non-blocking progress conditions. It also explains why the wait-free property is a natural basis for the consensus hierarchy: a theory of shared-memory computation requires an independent progress condition, not one that makes demands of the operating system scheduler.15th International Conference, OPODIS 2011, Toulouse, France, December 13-16, 2011. Proceeding
Fault-tolerant aggregation: flow-updating meets mass-distribution

The authors appear in alphabetical order.Flow-Updating (FU) is a fault-tolerant technique that has proved to be efficient in practice for the distributed computation of aggregate functions in communication networks where individual processors do not have access to global information. Previous distributed aggregation protocols, based on repeated sharing of input values (or mass) among processors, sometimes called Mass-Distribution (MD) protocols, are not resilient to communication failures (or message loss) because such failures yield a loss of mass.
In this paper, we present a protocol which we call Mass-Distribution with Flow-Updating (MDFU). We obtain MDFU by applying FU techniques to classic MD. We analyze the convergence time of MDFU showing that stochastic message loss produces low overhead. This is the first convergence proof of an FU-based algorithm. We evaluate MDFU experimentally, comparing it with previous MD and FU protocols, and verifying the behavior predicted by the analysis. Finally, given that MDFU incurs a fixed deviation proportional to the message-loss rate, we adjust the accuracy of MDFU heuristically in a new protocol called MDFU with Linear Prediction (MDFU-LP). The evaluation shows that both MDFU and MDFU-LP behave very well in practice, even under high rates of message loss and even changing the input values dynamically.This work is supported in part by the Comunidad de Madrid grant S2009TIC-1692, Spanish MICINN grant TIN2008–06735-C02-01, Portuguese FCT grant PTDC/EIA- EIA/104022/2008, and National Science Foundation grant CCF-093.7829
Towards consistency oblivious programming

It is well known that guaranteeing program consistency when accessing shared data comes at the price of degraded performance and scalability.
This paper initiates the investigation of consistency oblivious programming (COP). In COP, sections of concurrent code that meet certain criteria are executed without checking for consistency. However, checkpoints are added before any shared data modification to verify the algorithm was on the right track, and if not, it is re-executed in a more conservative and expensive consistent way. We show empirically that the COP approach can enhance a software transactional memory (STM) framework to deliver more efficient concurrent data structures from serial source code. In some cases the COP code delivers performance comparable to that of more complex fine-grained structures.15th International Conference, OPODIS 2011, Toulouse, France, December 13-16, 2011. Proceeding
Experiments with  embedded  system design  at UMinho  and  AIT

Nowadays,  embedded  systems  are  central  to  modern  life,
mainly due to the scientiﬁc and technological advances of the last decades
that started a new reality in which the embedded systems market has
been growing steadily, along with a monthly or even weekly emergence
of new products with diﬀerent applications across several domains. This
embedded system ubiquity was the drive for the following question ”Why
should we focus on embedded systems design?” that was answered in [1,
2] with the following points: (1) high and fast penetration in products
and services due to the integration of networking, operating system and
database capabilities, (2) very strategic ﬁeld economically and (3) a new
and relatively undeﬁned subject in academic environment. Other adja-
cent questions have been raised such as ”Why is the design of embedded
systems special?”. The answer for this last question is based mainly on
several problems raised by the new technologies, such as the need for
more human resources in specialized areas and high learning curve for
system designers. As pointed in [1], these problems can prevent many
companies from adopting these new technologies or force them not to
respond timely in mastering these technological and market challenges.
In this paper, it is described how staﬀ at ESRG-UMinho
1
and ISE-AIT
2
faced the embedded systems challenges at several levels. It starts to de-
scribe the development of the educational context for the new technolo-
gies and show how our Integrated Master Curriculum in Industrial Elec-
tronics and Computer Engineering has been adapted to satisfy the needs
of the major university customers, the industry
Leveraging different meronym discovery methods for bridging resolution in French

International audienceThis paper presents a statistical system for resolving bridging descriptions in French, a language for which current lexical resources have a very low overage. The system is similar to that developed for English by Poesio but it was enriched to integrate meronymic information extracted automatically from both web queries and raw text using syntactic patterns. Through various experiments on the DEDE corpus, we show that although still mediocre the performance of our system compare favorably to those obtained by Poesio for English. In addition, our evaluation indicates that the different meronym extraction methods have a cumulative effect, but that the text pattern-based extraction method is more robust and leads to higher accuracy than the web-based approach
Simulation of the Emotion Dynamics in a Group of Agents in an Evacuation Situation

International audienceNowadays, more and more emergency evacuation simulations are used to evaluate the safety level of a building during an emergency evacuation after an accident. The heart of this kind of simulations is the simulation of human behavior because simulation results depend for a big part on how this behavior is simulated. However, human behaviors in a real emergency situation are determined by a lot of cognitive mechanisms. In order to make the simulation more realistic, plenty of factors (e.g. innate characteristics, perception of the environment, internal rules, personality and even emotions) that affect human behaviors must be taken into account. This paper focuses on the influence of emotions, and more precisely on the influence of their dynamics and propagation from an agent to another. The main contribution of this work is the development of a model of emotions taking into account their dynamics and their propagation and its integration in an evacuation simulation. The first results of the simulation show the benefits of considering emotion propagation
Lectures on Quantum Black Holes

In these notes we describe recent progress in understanding finite size
corrections to the black hole entropy. Much of the earlier work concerning
quantum black holes has been in the limit of large charges when the area of the
even horizon is also large. In recent years there has been substantial progress
in understanding the entropy of supersymmetric black holes within string theory
going well beyond the large charge limit. It has now become possible to begin
exploring finite size effects in perturbation theory in inverse size and even
nonperturbatively, with highly nontrivial agreements between thermodynamics and
statistical mechanics. Unlike the leading Bekenstein-Hawking entropy which
follows from the two-derivative Einstein-Hilbert action, these finite size
corrections depend sensitively on the phase under consideration and contain a
wealth of information about the details of compactification as well as the
spectrum of nonperturbative states in the theory. Finite-size corrections are
therefore very interesting as a valuable window into the microscopic degrees of
freedom of the quantum theory.Comment: 79 pages, based on lectures given at the summer school 'Strings and
  Fundamental. Physics 2010' in Munic
Ontology-based user-defined rules and context-aware service composition system

The World Wide Web is becoming increasingly personalized as users provide more of their information on the Web. Thus, Web service functionality is becoming reliant on user pro le information and context in order to provide user-speci c data. In this paper, we discuss enhancements to SECE (Sense Everything, Control Everything), a platform for context-aware service composition based on user-de ned rules. We have enhanced SECE to interpret ontology descriptions of services. With this enhancement, SECE can now create user-de ned rules based on the ontology description of the service and interoperate within any service domain that has an ontology description. Additionally, it can use an ontology-based service discovery system like GloServ as its service\ud
discovery back-end in order to issue more complex queries for service discovery and composition. This paper discusses the design and implementation of these improvements.Peer ReviewedPostprint (author’s final draft