A high abstraction level approach for detecting feature interactions between telecommunication services

AbstractWhen several telecommunication services are running at the same time, undesirable behaviors may arise, which are commonly called feature interactions. Several methods have been developed for detecting and resolving feature interactions. However, most of these methods are based on detailed models of services, which make them suffer from state space explosion. Moreover, different telecommunication operators cannot cooperate to manage feature interactions by exchanging detailed service models because this violates the confidentiality principle. Our work is a part of the few attempts to develop feature interaction detection methods targeting to avoid or reduce significantly state space explosion. In order to reach this objective, we first develop a so called Cause–Restrict language to model subscribers of telecommunication services at a very high abstraction level. A Cause–Restrict model of a subscriber provides information such as: what is the cause of what, and what restricts (or forbids) what, and specifies coarsely the frequency of each operation “cause” or “restrict” by “always” or “sometimes”. Then, we develop a method that detects feature interactions between telecommunication services modeled in the Cause–Restrict language. We demonstrate the applicability of our approach by modeling several services and detecting several feature interactions between them. New feature interactions have been detected by our approach

Overcoming observability problems in distributed test architectures

This paper investigates conditions that must be satisfied by an FSM for the existence of input sequences that can be applied in a distributed test architecture without encountering controllability and observability problems and without using external coordination messages. Such conditions have two potential values. First, they can be used to determine whether we require coordination messages and thus a network that connects the testers. Second, if we wish to avoid the use of coordination messages in testing then these conditions can be seen as testability conditions that can inform the design process. Results given in this paper differ from those in the following ways. First, the conditions are strictly weaker than those in since we are less restrictive in the ways we achieve our goals. Second, only considered observability problems; we consider both controllability and observability problems. In addition, only considered a particular type of observability problem and we generalize this. Finally, we investigate the situation in which we need only add input sequences to complement a given test/checking sequence ρ and prove that the conditions for this problem are equivalent to those for the original problem

ProMap: Effective Bilingual Lexicon Induction via Language Model Prompting

Bilingual Lexicon Induction (BLI), where words are translated between two languages, is an important NLP task. While noticeable progress on BLI in rich resource languages using static word embeddings has been achieved. The word translation performance can be further improved by incorporating information from contextualized word embeddings. In this paper, we introduce ProMap, a novel approach for BLI that leverages the power of prompting pretrained multilingual and multidialectal language models to address these challenges. To overcome the employment of subword tokens in these models, ProMap relies on an effective padded prompting of language models with a seed dictionary that achieves good performance when used independently. We also demonstrate the effectiveness of ProMap in re-ranking results from other BLI methods such as with aligned static word embeddings. When evaluated on both rich-resource and low-resource languages, ProMap consistently achieves state-of-the-art results. Furthermore, ProMap enables strong performance in few-shot scenarios (even with less than 10 training examples), making it a valuable tool for low-resource language translation. Overall, we believe our method offers both exciting and promising direction for BLI in general and low-resource languages in particular. ProMap code and data are available at \url{https://github.com/4mekki4/promap}.Comment: To appear in IJCNLP-AACL 202

Canonical finite state machines for distributed systems

There has been much interest in testing from finite state machines (FSMs) as a result of their suitability for modelling or specifying state-based systems. Where there are multiple ports/interfaces a multi-port FSM is used and in testing, a tester is placed at each port. If the testers cannot communicate with one another directly and there is no global clock then we are testing in the distributed test architecture. It is known that the use of the distributed test architecture can affect the power of testing and recent work has characterised this in terms of local s-equivalence: in the distributed test architecture we can distinguish two FSMs, such as an implementation and a specification, if and only if they are not locally s-equivalent. However, there may be many FSMs that are locally s-equivalent to a given FSM and the nature of these FSMs has not been explored. This paper examines the set of FSMs that are locally s-equivalent to a given FSM M. It shows that there is a unique smallest FSM χmin(M) and a unique largest FSM χmax(M) that are locally s-equivalent to M. Here smallest and largest refer to the set of traces defined by an FSM and thus to its semantics. We also show that for a given FSM M the set of FSMs that are locally s-equivalent to M defines a bounded lattice. Finally, we define an FSM that, amongst all FSMs locally s-equivalent to M, has fewest states. We thus give three alternative canonical FSMs that are locally s-equivalent to an FSM M: one that defines the smallest set of traces, one that defines the largest set of traces, and one with fewest states. All three provide valuable information and the first two can be produced in time that is polynomial in terms of the number of states of M. We prove that the problem of finding an s-equivalent FSM with fewest states is NP-hard in general but can be solved in polynomial time for the special case where there are two ports

Decomposing Service Definition in Predicate/Transition-Nets for Designing Distributed Systems

In this paper, we propose a new algorithm for the derivation of a protocol specification in Pr/T-nets, which is the specification of communicating N entities (N can be given), from a given service specification in Pr/T-nets and an allocation of the places of the service specification to the N entities. Our algorithm decomposes each transition of the service specification into a set of communicating Pr/T-subnets running on the N entities. Moreover, for the efficient control of conflict of shared resources, we present a timestamp-based mutual exclusion algorithm and incorporate it into the derivation algorithm

La durabilité du système oasien face à la détérioration des ressources en eaux souterraines: cas de la palmeraie de Tafilalet

Oasis is a specific landscape that characterizes arid areas. The structure of oasis ecosystem depends mainly on desert-oasis-rivers components. Generally, oases are spread along non-perennial rivers (wadis) and shallow water table. However, the sustain-ability of oasis system is threatened by a combination of factors (water scarcity, Bayoud disease, climate change, rural exodus, etc.).The objective of this article is to highlight the crucial role of groundwater resources, although they remain invisible, play in the conservation and sustainability of oasis system. The aim is to understand and analyze the various interactions between groundwater table and the dynamics of palm groves, taking into consideration all existing factors (natural and human). A histori-cal analysis tracing both the oasis dynamics and the groundwater evolution has been established. A diachronic approach was adopted in order to reconstruct the history of the Tafilalet plain by performing a literature search that was supported by surveys conducted with different actors in this region. The results showed that groundwater is the basic resource for the survival of the oasis system in the Tafilalet plain. Besides being the main source for irrigation water supply, groundwater contributes directly in the water supply of the date palm, which represents the oases keystone. Key words: Oasis dynamics, Sustainability, Groundwater table, Date palm, Tafilalet.L’oasis est un écosystème dont la structure dépend principalement des composantes désert-oasis-rivières. Généralement, elles sont distribuées le long des rivières non pérennes (oueds) et sur les nappes phréatiques peu profondes. Toutefois, la durabilité du système oasien est menacée par plusieurs facteurs conjugués (Pénurie d’eau, Bayoud, changements climatiques, exode rural, etc..).L’objectif de cet article est de mettre en lumière l’importance des ressources en eau souterraines qui quoi qu’elles demeurent invisibles, ont joué un rôle primordial dans la conservation et la durabilité du système oasien. Il vise à comprendre et à analyser les différentes interactions entre la nappe souterraine (nappe phréatique) et la dynamique des palmeraies en prenant en considéra-tion l’ensemble des facteurs existants (naturels et humains). Une approche diachronique a été adoptée pour pouvoir reconstituer l’histoire de l’évolution de la plaine de Tafilalet dans son intégralité en effectuant une recherche bibliographique qui a été étayée par des enquêtes réalisées sur terrain avec les différents acteurs. Les résultats ont montré que la nappe souterraine est la ressource de base pour la survie du système oasien dans la plaine de Tafilalet. En plus d’être la principale source pour l’approvisionnement en eau d’irrigation, la nappe phréatique contribue directement dans l’alimentation hydrique du palmier dattier qui est le symbole du patrimoine oasien. Mots clés: Dynamique des oasis, nappe phréatique, palmier dattier, Tafilalet

Overcoming controllability problems in distributed testing from an input output transition system

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Springer VerlagThis paper concerns the testing of a system with physically distributed interfaces, called ports, at which it interacts with its environment. We place a tester at each port and the tester at port p observes events at p only. This can lead to controllability problems, where the observations made by the tester at a port p are not sufficient for it to be able to know when to send an input. It is known that there are test objectives, such as executing a particular transition, that cannot be achieved if we restrict attention to test cases that have no controllability problems. This has led to interest in schemes where the testers at the individual ports send coordination messages to one another through an external communications network in order to overcome controllability problems. However, such approaches have largely been studied in the context of testing from a deterministic finite state machine. This paper investigates the use of coordination messages to overcome controllability problems when testing from an input output transition system and gives an algorithm for introducing sufficient messages. It also proves that the problem of minimising the number of coordination messages used is NP-hard

Rare Case of Ischaemic Stroke Following Cervical Transforaminal Injection

We report a case of brainstem infarction following a C5–C6 cervical transforaminal injection, a rare and serious neurological complication of this procedure. Cervical transforaminal steroid injection is a common therapy for patients with persistent cervical radiculopathy not relieved by conservative treatment, and is effective in 65–70% of cases. Unfortunately, this procedure may lead to serious complications such as neurological damage. These complications are rare but potentially fatal, as reported in our case. Complications could be due to three mechanisms: the technique itself, the cervical vascular anatomy and the properties of the product (corticoids). The neurological complications can be diagnosed through brain MRI. This case report focuses on the importance of a risk/benefit evaluation when performing this medical procedure

Testing real-time systems using TINA

The paper presents a technique for model-based black-box conformance testing of real-time systems using the Time Petri Net Analyzer TINA. Such test suites are derived from a prioritized time Petri net composed of two concurrent sub-nets specifying respectively the expected behaviour of the system under test and its environment.We describe how the toolbox TINA has been extended to support automatic generation of time-optimal test suites. The result is optimal in the sense that the set of test cases in the test suite have the shortest possible accumulated time to be executed. Input/output conformance serves as the notion of implementation correctness, essentially timed trace inclusion taking environment assumptions into account. Test cases selection is based either on using manually formulated test purposes or automatically from various coverage criteria specifying structural criteria of the model to be fulfilled by the test suite. We discuss how test purposes and coverage criterion are specified in the linear temporal logic SE-LTL, derive test sequences, and assign verdicts