“Like a Whole Thing”: Dialogic Sensemaking in One Sixth Grade Classroom

This qualitative study used a constructivist approach to better understand how students in one sixth grade classroom participate in dialogic discussions while making sense of texts. Participants in the study attended a suburban, public, high-performing middle school in Pennsylvania. Drawing on Sociocultural Learning Theory and Transactional Reading Theory, the researcher observed one English Language Arts class. Nine students participated in five reading events over a period of two months. Data collection, informed by linguistic ethnographic methods, included audio recordings, transcriptions of reading events, fieldnotes, and transcriptions of one on one and small group interviews. In Vivo coding of the interview data helped to honor the voices of the participants, while initial coding of the dialogue led to the development of four themes centering on the talk moves students made when making sense of texts through dialogue: affirming ideas, testing ideas, teaching ideas, and holding onto ideas. Focusing on the perspectives of the students participating in the dialogue, the study revealed specific instructional frames and practices such as carefully constructing questions, providing access to discussion norms and sentence starters, and providing frequent opportunities to engage in dialogue, that enhance the ethos of the classroom community. The classroom culture was further enhanced by an understanding of how to engage in collaborative discussion and a sense of value in the group. The discussion includes implications for future educational practice based on these key findings

Runtime Verification Of SQL Correctness Properties with YR-DB-RUNTIME-VERIF

Software correctness properties are essential to maintain quality by continuous and regressive inte- gration testing, as well as runtime monitoring the program after customer deployment. This paper presents an effective and lightweight C ++ program verification framework: YR_DB_RUNTIME_VERIF, to check SQL (Structure Query Language) [1] software correctness properties specified as temporal safety properties [2]. A temporal safety property specifies what behavior shall not occur, in a software, as sequence of program events. YR_DB_RUNTIME_VERIF allows specification of a SQL temporal safety property by means of a very small state diagram mealy machine [3]. In YR_DB_RUNTIME_VERIF, a spec- ification characterizes effects of program events (via SQL statements) on database table columns by means of set interface operations (∈, ∈), and, enable to check these characteristics hold or not at runtime. Integration testing is achieved for instance by expressing a state diagram that encompasses both Graphical User Interface (GUI) states and MySQL [4] databases queries that glue them. For example, a simple specification would encompass states between ’Department administration’ and ’Stock listing’ GUI interfaces, and transitions between them by means of MySQL databases oper- ations. YR_DB_RUNTIME_VERIF doesn’t generate false warnings; YR_DB_RUNTIME_VERIF specifications are not desirable (forbidden) specifications (fail traces). This paper focuses its examples on MySQL database specifications, labeled as states diagrams events, for the newly developed and FOSS (Free and Open Source Software) Enterprise Resource Planing Software YEROTH–ERP–3.0 [5].PROF. DR.-ING. DIPL.-INF. xavier noumbissi noundo

PICO: A Presburger In-bounds Check Optimization for Compiler-based Memory Safety Instrumentations

Memory safety violations such as buffer overflows are a threat to security to this day. A common solution to ensure memory safety for C is code instrumentation. However, this often causes high execution-time overhead and is therefore rarely used in production. Static analyses can reduce this overhead by proving some memory accesses in bounds at compile time. In practice, however, static analyses may fail to verify in-bounds accesses due to over-approximation. Therefore, it is important to additionally optimize the checks that reside in the program. In this article, we present PICO, an approach to eliminate and replace in-bounds checks. PICO exactly captures the spatial memory safety of accesses using Presburger formulas to either verify them statically or substitute existing checks with more efficient ones. Thereby, PICO can generate checks of which each covers multiple accesses and place them at infrequently executed locations. We evaluate our LLVM-based PICO prototype with the well-known SoftBound instrumentation on SPEC benchmarks commonly used in related work. PICO reduces the execution-time overhead introduced by SoftBound by 36% on average (and the code-size overhead by 24%). Our evaluation shows that the impact of substituting checks dominates that of removing provably redundant checks

Model-driven Code Optimization

Although code optimizations have been applied by compilers for over 40 years, much of the research has been devoted to the development of particular optimizations. Certain problems with the application of optimizations have yet to be addressed, including when, where and in what order to apply optimizations to get the most benefit. A number of occurring events demand these problems to be considered. For example, cost-sensitive embedded systems are widely used, where any performance improvement from applying optimizations can help reduce cost. Although several approaches have been proposed for handling some of these issues, there is no systematic way to address the problems.This dissertation presents a novel model-based framework for effectively applying optimizations. The goal of the framework is to determine optimization properties and use these properties to drive the application of optimizations. This dissertation describes three framework instances: FPSO for predicting the profitability of scalar optimizations; FPLO for predicting the profitability of loop optimizations; and FIO for determining the interaction property. Based on profitability and the interaction properties, compilers will selectively apply only beneficial optimizations and determine code-specific optimization sequences to get the most benefit. We implemented the framework instances and performed the experiments to demonstrate their effectiveness and efficiency. On average, FPSO and FPLO can accurately predict profitability 90% of the time. Compared with a heuristic approach for selectively applying optimizations, our model-driven approach can achieve similar or better performance improvement without tuning the parameters necessary in the heuristic approach. Compared with an empirical approach that experimentally chooses a good order to apply optimizations, our model-driven approach can find similarly good sequences with up to 43 times compile-time savings.This dissertation demonstrates that analytic models can be used to address the effective application of optimizations. Our model-driven approach is practical and scalable. With model-driven optimizations, compilers can produce higher quality code in less time than what is possible with current approaches

Array bounds check elimination in the context of deoptimization

AbstractWhenever an array element is accessed, Java virtual machines execute a compare instruction to ensure that the index value is within the valid bounds. This reduces the execution speed of Java programs. Array bounds check elimination identifies situations in which such checks are redundant and can be removed. We present an array bounds check elimination algorithm for the Java HotSpot™ VM based on static analysis in the just-in-time compiler.The algorithm works on an intermediate representation in static single assignment form and maintains conditions for index expressions. It fully removes bounds checks if it can be proven that they never fail. Whenever possible, it moves bounds checks out of loops. The static number of checks remains the same, but a check inside a loop is likely to be executed more often. If such a check fails, the executing program falls back to interpreted mode, avoiding the problem that an exception is thrown at the wrong place.The evaluation shows a speedup near to the theoretical maximum for the scientific SciMark benchmark suite and also significant improvements for some Java Grande benchmarks. The algorithm slightly increases the execution speed for the SPECjvm98 benchmark suite. The evaluation of the DaCapo benchmarks shows that array bounds checks do not have a significant impact on the performance of object-oriented applications

Draining the Swamp: Micro Virtual Machines as Solid Foundation for Language Development

Many of today\u27s programming languages are broken. Poor performance, lack of features and hard-to-reason-about semantics can cost dearly in software maintenance and inefficient execution. The problem is only getting worse with programming languages proliferating and hardware becoming more complicated. An important reason for this brokenness is that much of language design is implementation-driven. The difficulties in implementation and insufficient understanding of concepts bake bad designs into the language itself. Concurrency, architectural details and garbage collection are three fundamental concerns that contribute much to the complexities of implementing managed languages. We propose the micro virtual machine, a thin abstraction designed specifically to relieve implementers of managed languages of the most fundamental implementation challenges that currently impede good design. The micro virtual machine targets abstractions over memory (garbage collection), architecture (compiler backend), and concurrency. We motivate the micro virtual machine and give an account of the design and initial experience of a concrete instance, which we call Mu, built over a two year period. Our goal is to remove an important barrier to performant and semantically sound managed language design and implementation

The Student Movement Volume 105 Issue 7: Putting the Finishing Touches on Fall Semester

NEWS Andrews Releases Spring 2021 Opening Plan, Amanda Cho Creating Visions for the Future, Joelle Kim Semester Reflections: Living During a Global Pandemic, Taylor Uphus PULSE The Best Drive-Through Meals, Masy Domecillo Reviewing Leaving the Shadowland of Stress, Depression, and Anxiety , Jessica Rim Study Tips: Re-Examining Routine, Wambui Karanja HUMANS Christmas vs. Thanksgiving, Interviewed by Abigail Lee Interview with Dongchan Kim, AUSA Executive Vice President, Interviewd by Ben Lee Studying Abroad in Argentina: An Interview with Lisiane Umuhire, Interviewed by TJ Hunter ARTS & ENTERTAINMENT Creative Spotlight: Ivan Rachath, Interviewed by Megan Napod Elementary, Hannah Cruse It\u27s Beginning to Sound A Lot Like Christmas!, Megan Napod IDEAS The Good, Kyara Samuels The Power of Resource, Evin N. Musgrove LAST WORD Fallen Titans: Remembering Alex Trebek and Rabbi Jonathan Sacks, Daniel Selfhttps://digitalcommons.andrews.edu/sm-105/1008/thumbnail.jp

Increasing the Performance and Predictability of the Code Execution on an Embedded Java Platform

This thesis explores the execution of object-oriented code on an embedded Java platform. It presents established and derives new approaches for the implementation of high-level object-oriented functionality and commonly expected system services. The goal of the developed techniques is the provision of the architectural base for an efficient and predictable code execution. The research vehicle of this thesis is the Java-programmed SHAP platform. It consists of its platform tool chain and the highly-customizable SHAP bytecode processor. SHAP offers a fully operational embedded CLDC environment, in which the proposed techniques have been implemented, verified, and evaluated. Two strands are followed to achieve the goal of this thesis. First of all, the sequential execution of bytecode is optimized through a joint effort of an optimizing offline linker and an on-chip application loader. Additionally, SHAP pioneers a reference coloring mechanism, which enables a constant-time interface method dispatch that need not be backed a large sparse dispatch table. Secondly, this thesis explores the implementation of essential system services within designated concurrent hardware modules. This effort is necessary to decouple the computational progress of the user application from the interference induced by time-sharing software implementations of these services. The concrete contributions comprise a spill-free, on-chip stack; a predictable method cache; and a concurrent garbage collection. Each approached means is described and evaluated after the relevant state of the art has been reviewed. This review is not limited to preceding small embedded approaches but also includes techniques that have proven successful on larger-scale platforms. The other way around, the chances that these platforms may benefit from the techniques developed for SHAP are discussed

Exclamatives : a Thematic Guide with Many Questions and Few Answers

Aquest article ofereix una visió de conjunt de l’estat de la recerca sobre les exclamatives, parant atenció al coneixement actual sobre problemes “clàssics’’, com ara la factivitat, el grau extrem o la relació entre les exclamatives i les interrogatives, i destacant nous reptes teòrics i empírics, com ara la contribució de les oracions exclamatives a un model dinàmic del discurs o la posició dels sintagmes exclamatius en la perifèria esquerra.In this paper a snapshot is offered of the state of the art in the research on exclamatives, reviewing our current understanding of “classic’’ issues, like factivity, high degree, or the relationship between exclamatives and interrogatives, and highlighting new theoretical and empirical challenges, such as the contribution of exclamative sentences to a dynamic model of discourse or the placement of exclamative phrases in the left-periphery

Achieving High Performance and High Productivity in Next Generational Parallel Programming Languages

Processor design has turned toward parallelism and heterogeneity cores to achieve performance and energy efficiency. Developers find high-level languages attractive because they use abstraction to offer productivity and portability over hardware complexities. To achieve performance, some modern implementations of high-level languages use work-stealing scheduling for load balancing of dynamically created tasks. Work-stealing is a promising approach for effectively exploiting software parallelism on parallel hardware. A programmer who uses work-stealing explicitly identifies potential parallelism and the runtime then schedules work, keeping otherwise idle hardware busy while relieving overloaded hardware of its burden. However, work-stealing comes with substantial overheads. These overheads arise as a necessary side effect of the implementation and hamper parallel performance. In addition to runtime-imposed overheads, there is a substantial cognitive load associated with ensuring that parallel code is data-race free. This dissertation explores the overheads associated with achieving high performance parallelism in modern high-level languages. My thesis is that, by exploiting existing underlying mechanisms of managed runtimes; and by extending existing language design, high-level languages will be able to deliver productivity and parallel performance at the levels necessary for widespread uptake. The key contributions of my thesis are: 1) a detailed analysis of the key sources of overhead associated with a work-stealing runtime, namely sequential and dynamic overheads; 2) novel techniques to reduce these overheads that use rich features of managed runtimes such as the yieldpoint mechanism, on-stack replacement, dynamic code-patching, exception handling support, and return barriers; 3) comprehensive analysis of the resulting benefits, which demonstrate that work-stealing overheads can be significantly reduced, leading to substantial performance improvements; and 4) a small set of language extensions that achieve both high performance and high productivity with minimal programmer effort. A managed runtime forms the backbone of any modern implementation of a high-level language. Managed runtimes enjoy the benefits of a long history of research and their implementations are highly optimized. My thesis demonstrates that converging these highly optimized features together with the expressiveness of high-level languages, gives further hope for achieving high performance and high productivity on modern parallel hardwar