An Initial Approach to Explaining SLA Inconsistencies

An SLA signed by all interested parties must be created carefully, avoiding contradictions between terms, because their terms could carry penalties in case of failure. However, this consistency checking may become a challenging task depending on the complexity of the agreement. As a consequence, an automated way of checking the consistency of an SLA document and returning the set of inconsistent terms of the agreement would be very appealing from a practical point of view. For instance, it enables the development of software tools that make the creation of correct SLAs and the consistency checking of imported SLAs easier for users. In this paper, we present the problem of explaining WSAgreement inconsistencies as a constraint satisfaction problem (CSP), and then we use a CSP solver together with an explanation engine to check the consistency and return the inconsistent terms. Furthermore, a proof-of-concept using Choco solver in conjunction with the Palm explanation engine has been developed

Using Automated Analysis of Temporal-Aware SLAS in Logistics

Service level agreements (SLAs) establish the terms in which a logistics service may be provided or consumed. During the last years we have been studying techniques to perform an automated analysis of expressive and realistic SLAs, which makes the agreement creation process easier for involved parties. Firstly, we extended WS-Agreement specification to allow to apply any type of validity periods to SLA terms. Later, we dealt with the automated analysis of SLAs by proposing the explaining of SLAs inconsistencies and non-compliance scenarios. in this paper we show how these contributions are necessary to enable a logistic scenario of package tracking by providing examples for each proposal. We also include a final discussion on the convenience of performing a merge of all contributions to enable a better application of SLAs to logistic scenarios

Explaining the Non-Compliance between Templates and Agreement Offers in WS-Agreement

A common approach to the process of reaching agreements is the publication of templates that guide parties to create agreement offers that are then sent for approval to the template publisher. in such scenario, a common issue the template publisher must address is to check whether the agreement offer received is compliant or not with the template. Furthermore, in the latter case, an automated explanation of the reasons of such non-compliance is very appealing. Unfortunately, although there are proposals that deal with checking the compliance, the problem of providing an automated explanation to the non-compliance has not yet been studied in this context. in this paper, we take a subset of the WS-Agreement recommendation as a starting point and we provide a rigorous definition of the explanation for the non-compliance between templates and agreement offers. Furthermore, we propose the use of constraint satisfaction problem (CSP) solvers to implement it and provide a proof-of-concept implementation. The advantage of using CSPs is that it allows expressive service level objectives inside SLAs

Leaf:wood allometry and functional traits together explain substantial growth rate variation in rainforest trees

Plant growth rates drive ecosystem productivity and are a central element of plant ecological strategies. For seedlings grown under controlled conditions, a large literature has firmly identified the functional traits that drive interspecific variation in growth rate. For adult plants, the corresponding knowledge is surprisingly poorly understood. Until recently it was widely assumed that the key trait drivers would be the same (e.g. specific leaf area, or SLA), but an increasing number of papers has demonstrated this not to be the case, or not generally so. New theory has provided a prospective basis for understanding these discrepancies. Here we quantified relationships between stem diameter growth rates and functional traits of adult woody plants for 41 species in an Australian tropical rainforest. From various cost-benefit considerations, core predictions included that: (i) photosynthetic rate would be positively related to growth rate; (ii) SLA would be unrelated to growth rate (unlike in seedlings where it is positively related to growth); (iii) wood density would be negatively related to growth rate; and (iv) leaf mass:sapwood mass ratio (LM:SM) in branches (analogous to a benefit:cost ratio) would be positively related to growth rate. All our predictions found support, particularly those for LM:SM and wood density; photosynthetic rate was more weakly related to stem diameter growth rates. Specific leaf area was convincingly correlated to growth rate, in fact negatively. Together, SLA, wood density and LM:SM accounted for 52 % of variation in growth rate among these 41 species, with each trait contributing roughly similar explanatory power. That low SLA species can achieve faster growth rates than high SLA species was an unexpected result but, as it turns out, not without precedent, and easily understood via cost-benefit theory that considers whole-plant allocation to different tissue types. Branch-scale leaf:sapwood ratio holds promise as an easily measurable variable that may help to understand growth rate variation. Using cost-benefit approaches teamed with combinations of leaf, wood and allometric variables may provide a path towards a more complete understanding of growth rates under field conditions

A Soft Constraint-Based Approach to QoS-Aware Service Selection

Service-based systems should be able to dynamically seek replacements for faulty or underperforming services, thus performing self-healing. It may however be the case that available services do not match all requirements, leading the system to grind to a halt. In similar situations it would be better to choose alternative candidates which, while not fulfilling all the constraints, allow the system to proceed. Soft constraints, instead of the traditional crisp constraints, can help naturally model and solve replacement problems of this sort. In this work we apply soft constraints to model SLAs and to decide how to rebuild compositions which may not satisfy all the requirements, in order not to completely stop running systems

The state of the science in generative SLA and its place in modern second language studies.

Manuscript. Published version in press (Studies in Second Language Acquisition, 2017)This article has two main goals. The first is to summarize and comment on the current state-of-affairs of generative approaches to SLA (GenSLA), thirty-five years into its history. This discussion brings the readership of SSLA up-to-date on the questions driving GenSLA agendas and clears up misconceptions about what GenSLA does and does not endeavor to explain. We engage key questions/debates/shifts within GenSLA such as focusing on the deterministic role of input in language acquisition, as well as expanding the inquiry to new populations and empirical methodologies and technologies used. The second goal is to highlight the place of GenSLA in the broader field of SLA. We argue that various theories of SLA are needed, showing that many existing SLA paradigms are much less mutually exclusive than commonly believed (cf. Rothman & VanPatten, 2013; Slabakova et al., 2014, 2015; VanPatten & Rothman, 2014) — especially in light of their different foci and research questions

Coverage Based Testing for Service Level Agreements

Service level agreements (SLAs) are typically used to specify rules regarding the consumption of services that are agreed between the providers of the service-based applications (SBAs) and their consumers. An SLA includes a list of terms that contain the guarantees that must be fulfilled during the provisioning and consumption of the services. Since the violation of such guarantees may lead to the application of potential penalties, it is important to assure that the SBA behaves as expected. In this paper, we propose a proactive approach to test SLA-aware SBAs by means of identifying test requirements, which represent situations that are relevant to be tested. To address this issue, we define a four-valued logic that allows evaluating both the individual guarantee terms and their logical relationships. Grounded in this logic, we devise a test criterion based on the modified condition decision coverage (MCDC) in order to obtain a cost-effective set of test requirements from the structure of the SLA. Furthermore by analyzing the syntax and semantics of the agreement, we define specific rules to avoid non-feasible test requirements. The whole approach has been automated and applied over an eHealth case study

Relationships Among Species Traits: Separating Levels Of Response And Identifying Linkages To Abundance

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117076/1/ecy20038411.pd

Pronunciation acquisition patterns of learners with different starting levels

This study described the results of an investigation into the effect of an intensive 12-week pronunciation course in British English which 30 Dutch female 1st-year university students of English took. They read out the same text before and after the course. Each student’s ‘before’ and ‘after’ tests were recorded. Before analysis of their results, students were split up into three groups on the basis of their general starting level: high, intermediate and low. The analysis involved a before- and after comparison of the pronunciation of eleven different phonemes: /æ, ɒ, ɔː, ʌ, ʊ, d, θ/, medial /t/, coda /r/, and syllable-final /d, v/. The analysis was done by means of both auditory and acoustic analysis. Four degrees of success (or lack thereof) were defined. The results show that the consonants required the least effort, as they were already relatively acceptable before the course started. This was true of students in general, regardless of initial starting level. The three levels of students are most distinguishable on the basis of the development of the consonants during the course. The weaker students’ consonants in particular benefitted from the course. The research revealed that initial level can be used to predict the trajectory of improvement. A general conclusion is that teachers may recognise types of students before the course starts and subject them to different types of teaching