Component Instances Research Articles

What are the ethical obligations when a colleague has provided suboptimal care?

What are the ethical obligations when a colleague has provided suboptimal care?

Contextual priming of word meanings is stabilized over sleep

Evidence is growing for the involvement of consolidation processes in the learning and retention of language, largely based on instances of new linguistic components (e.g., new words). Here, we assessed whether consolidation effects extend to the semantic processing of highly familiar words. The experiments were based on the word-meaning priming paradigm in which a homophone is encountered in a context that biases interpretation towards the subordinate meaning. The homophone is subsequently used in a word-association test to determine whether the priming encounter facilitates the retrieval of the primed meaning. In Experiment 1 (N = 74), we tested the resilience of priming over periods of 2 and 12 h that were spent awake or asleep, and found that sleep periods were associated with stronger subsequent priming effects. In Experiment 2 (N = 55) we tested whether the sleep benefit could be explained in terms of a lack of retroactive interference by testing participants 24 h after priming. Participants who had the priming encounter in the evening showed stronger priming effects after 24 h than participants primed in the morning, suggesting that sleep makes priming resistant to interference during the following day awake. The results suggest that consolidation effects can be found even for highly familiar linguistic materials. We interpret these findings in terms of a contextual binding account in which all language perception provides a learning opportunity, with sleep and consolidation contributing to the updating of our expectations, ready for the next day.

Using mobile puzzles to exhibit certain algebraic habits of mind and demonstrate symbol-sense in primary school students

Given the growing concern for developing students’ algebraic ideas and thinking in earlier grades (NCTM, 2000) it is important for students to have experiences that better prepare them for their formal introduction to algebra. Mobile puzzles seem to be an opportunity for exhibiting certain algebraic habits of mind as well as for demonstrating symbol-sense which might support students in their transition from arithmetic to algebra. These puzzles include multiple balanced collections of objects whose weights must be determined by the solver. The arms/beams must be perfectly balanced for it to hang properly. Therefore, they represent, in a pictorial way, systems of equations. Each arm/beam that balances two sets of objects (representing variables as unknown “weights”) represents an equation. The data derived from Grade-6 students who were asked to solve a collection of tasks reflect the presence of the “Puzzling and Persevering” and “Seeking and Using Structure” habits of mind. At the same time these data incorporate instances of some main components of symbol-sense such as “friendliness with symbols”, “manipulating and ‘reading through’ symbolic expressions”, and “choice of symbols”. Also discussed is the way this experience contributes to an intuitive application of the conventional rules for solving equations that will be later introduced to the students as the standard algebraic “moves”.

RConf(PD): Automated resource configuration of complex services in the cloud

Optimal deployment of complex services in a virtualized environment is still an open problem. These services typically consist of a set of connected components, and each component may consist of multiple instances. Each instance can in turn be run in different virtual flavors, while the service constructed by the combination of these instances must satisfy a customer Service Level Objective (SLO).While there have been efforts to answer the questions of when to provision additional resources in a running service, and how many resources are needed, the question of what (i.e., which combination of instances) should be provisioned has not been investigated yet. In this work, we offer to service providers, the first system that automatically deploys component instances for complex services such that the resource utilization at the provider’s premises is maximized in the presence of customer constraints.Our system consists of two key technologies (RConf and RConfPD), both of which build on an analytical model based on robust queueing theory to accurately model arbitrary components. With the help of this model, RConf proposes an algorithm to ultimately find the optimal combination of component instances. Our real-world experiments show that, compared to greedy approaches, RConf provisions 20% less resources in the first place, and can reduce resource wastage on live resources by up to 50%. At the same time, RConfPD trades-off some of the optimality of RConf for a computational expense 1–2 orders of magnitude below that of RConf to provision time-sensitive services. Based on a primal–dual algorithm framework RConfPD relaxes the optimality constraints of RConf and removes dominated combinations to determine an approximation for the optimal solution. Our evaluation shows that RConfPD allows for fast decisions (in many cases <1ms), while maintaining 80%–99% of the solution quality of RConf.

An approach for managing the dynamic reconfiguration of software architectures

Currently, most software systems have a dynamic nature and need to evolve at runtime. The dynamic reconfiguration of software systems is a mechanism that must be dealt with to enable the creation and destruction of component instances and their links. To reconfigure a software system, it must be stopped, patched and restarted; this causes unavailability periods which are always a problem for highly available systems. In order to address these problems, this paper presents an approach called software architecture reconfiguration approach (SAREA). We define for this approach a set of intelligent agents, each of them has a precise role in the functioning and the control of software. Our approach implements a restoring mechanism of software architecture to a fully functional state after the failure of one or more reconfiguration operations; it also proposes a reconfiguration mechanism which describes the execution process of reconfigurations.

How do you handle a colleague who regularly does not inform his or her patients of all needed treatment?

How do you handle a colleague who regularly does not inform his or her patients of all needed treatment?

Reliability-redundancy-location allocation with maximum reliability and minimum cost using search techniques

ContextA safety critical system requires an automated and optimal allocation of redundant component instances to its existing components, including: 1) the selection of components (locations) on which the redundancy must be applied, 2) how many redundant component instances of varying reliability and cost should be allocated to each selected location. ObjectiveOur work aims to searching for the near optimal allocation solutions achieving the higher reliability of the system within the allowed cost. Such allocation must be made earlier, for example, while designing the architecture of the system to avoid unnecessary complexity of addressing unsafe situations discovered in the system development and deployment phases. MethodWith the above objective in mind, we propose a search-based allocation approach based on the overall objectives of maximizing the overall system reliability and minimizing the cost of introducing and allocating redundancy structures to the system. The architecture of a system modeled using the Unified Modeling Language (UML) along with redundancy structures is encoded as an optimization problem. To guide a search algorithm to solve the problem, we propose a fitness function based on the two optimization objectives: high reliability and low cost. ResultsWe empirically evaluated the performance of four search algorithms (Genetic Algorithm, (1 + 1) Evolutionary Algorithm, Alternating Variable Method (AVM) and Random Search) together with the proposed fitness function on 10 real-world Subsea Oil&Gas Production Systems of varying complexity. Results show that the AVM algorithm significantly outperforms the rest. ConclusionBased on the results of empirical evaluation, we found that AVM can provide the best allocation of redundancy structures as compared to the rest of the algorithms. On average, AVM provided 0.008% of more reliability while saving 26.78% on allocation cost as compared to RS. Our novel solution based on the results of empirical evaluation is implemented as a software tool.

Explicit connection patterns (ECP) profile and semantics for modelling and generating explicit connections in complex UML composite structures

Model-driven engineering can help in mitigating ever-growing complexity of modern software systems. In this sense, the Unified Modelling Language (UML) has gained a thick share in the market of modelling languages adopted in industry. Nevertheless, the generality of UML can make it hard to build complete code generators, simulators, model-based analysis or testing tools without setting variability in the semantics of the language. To tailor semantics variability the notion of semantic variation point has been introduced in UML 2.0.Our research focuses on the semantic variation point that leaves the rules for matching multiplicities of connected instances of components and ports undecided in UML composite structures. In order to allow model analysability, simulation and code generation, this semantics needs to be set. At the same time, leaving the burden of this task to the developers is often overwhelming for complex systems.In this paper we provide a solution for supporting modelling and automatic calculation and generation of explicit interconnections in complex UML composite structures. This is achieved by (i) defining a set of connection patterns, in terms of a UML profile, and related semantic rules for driving the calculation, (ii) providing a generation algorithm to calculate the explicit interconnections.

A scalable component model for multi-tenant SaaS application

A multi-tenant software as a service SaaS application provides a customised run-time application for each tenant using a single application. Multi-tenancy offers various advantages including reduced software development time, lower maintenance cost, effective version control and much more. However, managing large scale resources and providing superior user experience using the underlying resources is a key challenge in the management of SaaS application. Moreover, SaaS applications have fluctuating load based on tenant's users demand. Scalability of application in cloud is one of the foremost requirements in designing and implementing SaaS-based applications. In this paper, we propose an application's component-based scalable component model SCM, instances of application are created at component level and dynamically scaled based on the component's load considering various factors including tenant users attributes. Our evaluation and discussions show that the proposed multi-instance SCM offers enhanced application load distribution and offers improved application response time and effective utilisation of component instances.

Ethical obligations when concerned about the work of another dentist

Q I received a call from a dentist who has a highly educated patient who gets “routine cleanings” at his office and gets any necessary treatment from another dentist, Dr. X, who calls himself a “holistic dentist.” Dr. X recommended to the patient that she have 2 mandibular anterior teeth, previously treated endodontically, extracted. The teeth were completely asymptomatic and “within normal limits.” Dr. X told the patient that endodontically treated teeth are a nidus of infection because they contain a foreign body, referring to the endodontic filling material. The patient had the teeth removed and is planning further prosthetic replacement. The questioning dentist was a former member of his state dental board. He recognized Dr. X’s name; Dr. X had been investigated in the past and received a censure for doing the same “treatment” as stated above. What are the ethical obligations of the questioning dentist?

STRATEGY FOR SCALABLE SCENARIOS MODELING AND CALCULATION IN EARLY SOFTWARE RELIABILITY ENGINEERING

System scenarios derived from requirements specification play an important role in the early software reliability engineering. A great deal of research effort has been devoted to predict reliability of a system at early design stages. The existing approaches are unable to handle scalability and calculation of scenarios reliability for large systems. This paper proposes modeling of scenarios in a scalable way by using a scenario language that describes system scenarios in a compact and concise manner which can results in a reduced number of scenarios. Furthermore, it proposes a calculation strategy to achieve better traceability of scenarios, and avoid computational complexity. The scenarios are pragmatically modeled and translated to finite state machines, where each state machine represents the behaviour of component instance within the scenario. The probability of failure of each component exhibited in the scenario is calculated separately based on the finite state machines. Finally, the reliability of the whole scenario is calculated based on the components’ behaviour models and their failure information using modified mathematical formula. In this paper, an example related to a case study of an automated railcar system is used to verify and validate the proposed strategy for scalability of system modeling.

Understanding Inquiry as Stance: Illustration and Analysis of One Teacher Researcher’s Work

The development of "inquiry as stance" is a foundational component of the teacher research movement. Yet, it is difficult to exemplify this construct to gain insights into its meaning and what it might look like in practice. The purpose of this article is to initiate discussion about the construct of stance through the provision and analysis of an eight-minute video clip depicting one teacher researcher’s work. Three components of stance are discussed in relationship to the video example: (1) Data Collection as a Part of Teaching, (2) Roles of Inquirer and Teacher Blend Seamlessly With One Another, and (3) Commitment to the Creation of More Equitable Classrooms.

Coupled segmentation and similarity detection for architectural models

Recent shape retrieval and interactive modeling algorithms enable the re-use of existing models in many applications. However, most of those techniques require a pre-labeled model with some semantic information. We introduce a fully automatic approach to simultaneously segment and detect similarities within an existing 3D architectural model. Our framework approaches the segmentation problem as a weighted minimum set cover over an input triangle soup, and maximizes the repetition of similar segments to find a best set of unique component types and instances. The solution for this set-cover formulation starts with a search space reduction to eliminate unlikely combinations of triangles, and continues with a combinatorial optimization within each disjoint subspace that outputs the components and their types. We show the discovered components of a variety of architectural models obtained from public databases. We demonstrate experiments testing the robustness of our algorithm, in terms of threshold sensitivity, vertex displacement, and triangulation variations of the original model. In addition, we compare our components with those of competing approaches and evaluate our results against user-based segmentations. We have processed a database of 50 buildings, with various structures and over 200K polygons per building, with a segmentation time averaging up to 4 minutes.

An Investigation into Pragmatic Knowledge in the Reading Section of TOLIMO, TOEFL, and IELTS Examinations

The present study focused on the analysis of listening sections of two international English proficiency tests, i.e. IELTS and TOEFL tests, and one local English proficiency test, i.e. TOLIMO from pragmatic perspective. An attempt was made to explore the areas of pragmatic knowledge presented, and to assess test takers’ pragmatic knowledge. For this purpose, 250 items from each of these three proficiency tests were collected and analyzed. IELTS and TOLIMO tests were taken from preparation textbooks available in the market, and TOEFL tests were taken from the tests administered from 2000 to 2004. To elucidate what areas of pragmatic knowledge was involved in each item, Jung’s (2002) classification of components of pragmatic knowledge was used. In this study, pragmatic knowledge, includedthe ability to perform speech acts, the ability to convey and interpret non-literal meanings, the ability to perform politeness functions, the ability to perform discourse functions, and the ability to use cultural knowledge. The results of the study showed that TOLIMO, TOEFL and IELTS tests are able to assess test takers’ pragmatic knowledge; however, higher instances of pragmatic knowledge components were involved in TOEFL and TOLIMO test.

What Are Dentists' Ethical Obligations Regarding the Provision of Emergency Care When They Are Not Available to Provide That Care?

What Are Dentists' Ethical Obligations Regarding the Provision of Emergency Care When They Are Not Available to Provide That Care?

A cooperative group optimization system

A cooperative group optimization (CGO) system is presented to implement CGO cases by integrating the advantages of the cooperative group and low-level algorithm portfolio design. Following the nature-inspired paradigm of a cooperative group, the agents not only explore in a parallel way with their individual memory, but also cooperate with their peers through the group memory. Each agent holds a portfolio of (heterogeneous) embedded search heuristics (ESHs), in which each ESH can drive the group into a stand-alone CGO case, and hybrid CGO cases in an algorithmic space can be defined by low-level cooperative search among a portfolio of ESHs through customized memory sharing. The optimization process might also be facilitated by a passive group leader through encoding knowledge in the search landscape. Based on a concrete framework, CGO cases are defined by a script assembling over instances of algorithmic components in a toolbox. A multilayer design of the script, with the support of the inherent updatable graph in the memory protocol, enables a simple way to address the challenge of accumulating heterogeneous ESHs and defining customized portfolios without any additional code. The CGO system is implemented for solving the constrained optimization problem with some generic components and only a few domain-specific components. Guided by the insights from algorithm portfolio design, customized CGO cases based on basic search operators can achieve competitive performance over existing algorithms as compared on a set of commonly-used benchmark instances. This work might provide a basic step toward a user-oriented development framework, since the algorithmic space might be easily evolved by accumulating competent ESHs.

Compressing 3D Trees With Rendering Efficiency Based on Differential Data

Trees or forests are indispensable and ubiquitous in virtual outdoor environments. Artists usually use high polygon counts to construct detailed 3D tree models to increase realism. However, large memory spaces are required, and considerable computation power is used for rendering. This paper proposes a compression method for 3D tree models to achieve rendering efficiency with less memory space and high visual fidelity of trees simultaneously. Trees are clustered using automatic K-medoids clustering method, and each member tree in the cluster can be reconstructed based on the representative tree with differential data. An abstract representation of an ordered rooted tree for each tree model is introduced, and the similarity between trees was measured using the modified tree edit distance. Moreover, an LOD priority for each component was associated to facilitate the LOD mechanism by considering the contribution to the visual perception after rendering. For accelerating rendering, GPU was exploited to benefit the LOD mechanism, and the geometry instancing facilitates the rendering for component instances shared among member trees. The effectiveness of compression was tested using four sample forests. As demonstrated by the experimental results, our method can save substantial memory space, retain the visual fidelity of the reconstructed trees, and accelerate the rendering.

Design of component-based real-time applications

This paper presents the key aspects of a model-based methodology that is proposed for the design of component-based applications with hard real-time requirements. The methodology relies on RT-CCM (Real-time Container Component Model), a component technology aimed to make the timing behaviour of the applications predictable and inspired in the Lightweight CCM specification of the OMG. Some new mechanisms have been introduced in the underlying framework that make it possible to schedule the execution of code and the transmission of messages of an application while guaranteeing that the application will meet its timing requirements when executed. The added mechanisms also enable the application designer to configure this scheduling without interfering with the opacity typically required in component management. Moreover, the methodology includes a process for generating the real-time model of a component-based application as a composition of the reusable real-time models of the components that form it. From the analysis of this model the application designer obtains the configuration values that must be applied to the component instances and the elements of the framework in order to make the application fulfil its timing requirements.

A three-level component model in component based software development

Component-based development promotes a software development process that focuses on component reuse. How to describe a desired component before searching in the repository? How to find an existing component that fulfills the required functionalities? How to capture the system personalization based on its constitutive components' customization? To answer these questions, this paper claims that components should be described using three different forms at three development stages: architecture specification, configuration and assembly. However, no architecture description language proposes such a detailed description for components that supports such a three step component-based development. This paper proposes a three-level Adl, named Dedal, that enables the explicit and separate definitions of component roles, component classes, and component instances.

A type system for counting instances of software components

We identify an abstract language for component software based on process algebra. Besides the usual operators for sequential, alternative and parallel composition, it has primitives for instantiating components and for deleting instances of components. We define an operational semantics for our language and give a type system in which types express quantitative information on the components involved in the execution of the expressions of the language. Included in this information is for each component the maximum number of instances that are simultaneously active during the execution of the expression. The type system is compositional by the novel use of ‘deficit types’. The type inference algorithm runs in time quadratic in the size of the input. We consider extensions of the language with loops and tail recursion, and with a scope mechanism. We illustrate the approach with some examples, one on UML diagram refinement and one on counting objects on the free store in C++.