Resumo Pretende-se estudar a qualidade da Escala do Funcionamento Familiar (versão portuguesa) e compreender/caracterizar a relação entre o Funcionamento Familiar e os Estilos Parentais. A amostra inclui 1757 pais portugueses, sendo 77,3% do sexo feminino (N=1359), com idades entre os 20 e os 80 anos (M=41,61; DP=5,71). Os resultados confirmam uma relação entre as dimensões do funcionamento familiar e dos estilos parentais, especialmente com o suporte emocional. Os pais entre 36 e 45 anos apresentam um funcionamento familiar mais positivo e um estilo parental associado a níveis mais elevados de suporte emocional, níveis mais baixos de rejeição e níveis moderados de controlo/supervisão. Conclui-se que é um instrumento válido, sensível e robusto, e os resultados são um contributo para a investigação e intervenção psicossocial.
Abstract It is intended to study the quality of the Family Functioning Scale (Portuguese version) and to understand/characterize the relationship between Family Functioning and Parenting Styles. The samples include 1757 Portuguese parents, 77.3% being female (N=1359), aged between 20 and 80 years old (M=41.61; SD=5.71). The results confirm a relationship between the dimensions of family functioning and parenting styles, especially with the emotional support dimension. Parents between 36 and 45 years old have a more positive family functioning and a parenting style associated with higher levels of emotional support, lower levels of rejection, and moderate levels of control/supervision. It is concluded that it is a valid, sensitive, and robust instrument, and the results are a contribution to psychosocial research and intervention.
Persistent Memory (PM) is non-volatile byte-addressable memory that offers read and write latencies in the order of magnitude smaller than flash storage, such as SSDs. This survey discusses how file systems address the most prominent challenges in the implementation of file systems for Persistent Memory. First, we discuss how the properties of Persistent Memory change file system design. Second, we discuss work that aims to optimize small file I/O and the associated meta-data resolution. Third, we address how existing Persistent Memory file systems achieve (meta) data persistence and consistency.
The C programming language was developed in the 1970s as a fairly unconventional systems and operating systems development tool, but has, through the course of the ISO Standards process, added many attributes of more conventional programming languages and become less suitable for operating systems development. Operating system programming continues to be done in non-ISO dialects of C. The differences provide a glimpse of operating system requirements for programming languages.
This paper suggests a new memory partitioning scheme that can enhance process lifecycle, while avoiding Low Memory Killer and Out-of-Memory Killer operations on mobile devices. Our proposed scheme offers the complete concept of virtual memory nodes in operating systems of Android devices.
During the execution of a job, it may suspend itself, i.e., its computation ceases to process until certain activities are complete to be resumed. This paper provides a counterexample of the schedulability analysis by Devi in Euromicro Conference on Real-Time Systems (ECRTS) in 2003, which is the only existing suspension-aware analysis specialized for uniprocessor systems when preemptive earliest-deadline-first (EDF) is applied for scheduling dynamic selfsuspending tasks.
Existing memory management mechanisms used in commodity computing machines typically adopt hardware based address interleaving and OS directed random memory allocation to service generic application requests. These conventional memory management mechanisms are challenged by contention at multiple memory levels, a daunting variety of workload behaviors, and an increasingly complicated memory hierarchy. Our ISCA-41 paper proposes vertical partitioning to eliminate shared resource contention at multiple levels in the memory hierarchy. Combined with horizontal memory management policies, our framework supports a flexible policy space for tackling diverse application needs in production environment and is suitable for future heterogeneous memory systems.
This book describes the source code of the NetBSD Operating System Release 1.6 in SUN UltraSPARC 64-bit platform by annotating related excerpts from references and user manuals on the NetBSD Operating System. The goal of this book is to provide necessary information to understand the operation and the implementation of I/O subsystems in the kernel as well as to design and implement a new filesystem on the NetBSD platform.
Large number of cores and hardware resource sharing are two characteristics on multicore processors, which bring new challenges for the design of operating systems. How to locate and analyze the speedup restrictive factors in operating systems, how to simulate and avoid the phenomenon that speedup decreases with the number of cores because of lock contention (i.e., lock thrashing) and how to avoid the contention of shared resources such as the last level cache are key challenges for the operating system scalability research on multicore systems.
Sumit Sharma, Rohitt Sharma, Paramjit Singh
et al.
This paper proposes the creation of different interfaces in the mobile operating system for different age groups. The different age groups identified are kids, elderly people and all others. The motive behind creating different interfaces is to make the smartphones of today's world usable to all age groups.
Our goal is to provide a sufficient schedulability test -ideally polynomial- for the scheduling of Non-Cyclic Generalized Multiframe Task Model using Fixed-Task-Priority schedulers. We report two first results: (i) we present and prove correct the critical instant for the Non-Cyclic Generalized Multiframe Task Model then (ii) we propose an algorithm which provides a sufficient (but pseudo-polynomial) schedulability test.
Teaching Unix to new students is a common tasks in many higher schools. This paper presents an approach to such course where the students progress autonomously with the help of the teacher. The traditional textbook is complemented with a wiki, and the main thread of the course is a game, in the form of a treasure hunt. The course finishes with a lab exam, where students have to perform practical manipulations similar to the ones performed during the treasure hunt. The exam is graded fully automatically. This paper discusses the motivations and advantages of the approach, and gives an overall view of the tools we developed. The tools are available from the web, and open-source, hence re-usable outside the Ensimag.
An optimal solution to the problem of scheduling real-time tasks on a set of identical processors is derived. The described approach is based on solving an equivalent uniprocessor real-time scheduling problem. Although there are other scheduling algorithms that achieve optimality, they usually impose prohibitive preemption costs. Unlike these algorithms, it is observed through simulation that the proposed approach produces no more than three preemptions points per job.
Patrick Meumeu Yomsi, Vincent Nelis, Joël Goossens
In this paper, we address the scheduling problem of multi-mode real-time systems upon uniform multiprocessor platforms. We propose two transition protocols, specified together with their schedulability test, and provide the reader with two distinct upper bounds for the length of the transient phases during mode transitions, respectively for the cases where jobs priorities are known and unknown beforehand.
Virtual memory of computers is usually implemented by demand paging. For some page replacement algorithms the number of page faults may increase as the number of page frames increases. Belady, Nelson and Shedler constructed reference strings for which page replacement algorithm FIFO produces near twice more page faults in a larger memory than in a smaller one. They formulated the conjecture that 2 is a general bound. We prove that this ratio can be arbitrarily large.
In this paper we consider the scheduling of periodic and parallel rigid tasks. We provide (and prove correct) an exact schedulability test for Fixed Task Priority (FTP) Gang scheduler sub-classes: Parallelism Monotonic, Idling, Limited Gang, and Limited Slack Reclaiming. Additionally, we study the predictability of our schedulers: we show that Gang FJP schedulers are not predictable and we identify several sub-classes which are actually predictable. Moreover, we extend the definition of rigid, moldable and malleable jobs to recurrent tasks.
In this paper we study the scheduling of (m,k)-firm synchronous periodic task systems using the Distance Based Priority (DBP) scheduler. We first show three phenomena: (i) choosing, for each task, the initial k-sequence 1^k is not optimal, (ii) we can even start the scheduling from a (fictive) error state (in regard to the initial k-sequence) and (iii) the period of feasible DBP-schedules is not necessarily the task hyper-period. We then show that any feasible DBP-schedule is periodic and we upper-bound the length of that period. Lastly, based on our periodicity result we provide an exact schedulability test.
M. Abdelsalam Hassan, Keishi Sakanushi, Yoshinori Takeuchi
et al.
This paper presents the methodology and the modeling constructs we have developed to capture the real time aspects of RTOS simulation models in a System Level Design Language (SLDL) like SystemC. We describe these constructs and show how they are used to build a simulation model of an RTOS kernel targeting the $μ$-ITRON OS specification standard.