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<p>This study examines issues arising from the popular use of technology and social networking in the classroom during lecture and its effect on student grades. Data were collected in a first year social science course. Findings of a general survey show that the use of technology and social networking during lecture is a popular form for multitasking with little impact on grades up to a certain threshold. Addressing this issue, this paper puts forth a broad historical overview of the use of leisure activities by workers during preindustrialization and industrialized capitalism. Through an examination of multitasking during lectures, this paper will assess the extent to which social norms of time discipline may be changing and the impacts this could have on the future of work organization. Activity theory is one method of guiding research in order to incorporate these multitasking activities into teaching and learning paradigms and policies for use in the classroom.</p> / Master of Arts (MA)

Indiana University-Purdue University Indianapolis (IUPUI) / In today’s workforce, multitasking on the job has become increasingly important. However, past research has characterized multitasking primarily as a counterproductive work strategy. Drawing from the theory of person-job (PJ) fit, in this this study it is proposed that multitasking may not always result in performance decrements but rather that people’s perceptions and experiences of multitasking may differ depending on individual differences. The theory of PJ fit suggests positive outcomes when there is a match between employee preferences, abilities and job characteristics. Using this framework, this study proposes the concept of multitasking fit and predicts that a match between multitasking preferences and multitasking job demands will result in positive work attitudes. Lastly, it is predicted that higher working memory will lead to higher job performance, especially in jobs requiring higher amounts of multitasking. This study found that PJ fit had generally positive effects on work-related outcomes such as job satisfaction, organizational commitment, turnover intentions, and strains. Due to measurement issues, the relationship between working memory and job performance could not be assessed. However, the results of this study relating to PJ fit suggest that perhaps multitasking is not always a bad strategy within the workplace and that its consequences may instead depend on the degree of fit between an individual and his or her working environment.

by Keith, Hang-kwong Mak. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 122-127). / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background --- p.4 / Chapter 2.1 --- Read/Write Model --- p.4 / Chapter 2.2 --- Abstract Data Type Model --- p.5 / Chapter 2.3 --- Overview of Semantics-Based Concurrency Control Protocols --- p.7 / Chapter 2.4 --- Concurrency Hierarchy --- p.9 / Chapter 2.5 --- Control Flow of the Strict Two Phase Locking Protocol --- p.11 / Chapter 2.5.1 --- Flow of an Operation --- p.12 / Chapter 2.5.2 --- Response Time of a Transaction --- p.13 / Chapter 2.5.3 --- Factors Affecting the Response Time of a Transaction --- p.14 / Chapter 3 --- Semantics-Based Concurrency Control Protocols --- p.16 / Chapter 3.1 --- Strict Two Phase Locking --- p.16 / Chapter 3.2 --- Conflict Relations --- p.17 / Chapter 3.2.1 --- Commutativity (COMM) --- p.17 / Chapter 3.2.2 --- Forward and Right Backward Commutativity --- p.19 / Chapter 3.2.3 --- Exploiting Context-Specific Information --- p.21 / Chapter 3.2.4 --- Relaxing Correctness Criterion by Allowing Bounded Inconsistency --- p.26 / Chapter 4 --- Related Work --- p.32 / Chapter 4.1 --- Exploiting Transaction Semantics --- p.32 / Chapter 4.2 --- Exploting Object Semantics --- p.34 / Chapter 4.3 --- Sacrificing Consistency --- p.35 / Chapter 4.4 --- Other Approaches --- p.37 / Chapter 5 --- Performance Study (Testbed Approach) --- p.39 / Chapter 5.1 --- System Model --- p.39 / Chapter 5.1.1 --- Main Memory Database --- p.39 / Chapter 5.1.2 --- System Configuration --- p.40 / Chapter 5.1.3 --- Execution of Operations --- p.41 / Chapter 5.1.4 --- Recovery --- p.42 / Chapter 5.2 --- Parameter Settings and Performance Metrics --- p.43 / Chapter 6 --- Performance Results and Analysis (Testbed Approach) --- p.46 / Chapter 6.1 --- Read/Write Model vs. Abstract Data Type Model --- p.46 / Chapter 6.2 --- Using Context-Specific Information --- p.52 / Chapter 6.3 --- Role of Conflict Ratio --- p.55 / Chapter 6.4 --- Relaxing the Correctness Criterion --- p.58 / Chapter 6.4.1 --- Overhead and Performance Gain --- p.58 / Chapter 6.4.2 --- Range Queries using Bounded Inconsistency --- p.63 / Chapter 7 --- Performance Study (Simulation Approach) --- p.69 / Chapter 7.1 --- Simulation Model --- p.70 / Chapter 7.1.1 --- Logical Queueing Model --- p.70 / Chapter 7.1.2 --- Physical Queueing Model --- p.71 / Chapter 7.2 --- Experiment Information --- p.74 / Chapter 7.2.1 --- Parameter Settings --- p.74 / Chapter 7.2.2 --- Performance Metrics --- p.75 / Chapter 8 --- Performance Results and Analysis (Simulation Approach) --- p.76 / Chapter 8.1 --- Relaxing Correctness Criterion of Serial Executions --- p.77 / Chapter 8.1.1 --- Impact of Resource Contention --- p.77 / Chapter 8.1.2 --- Impact of Infinite Resources --- p.80 / Chapter 8.1.3 --- Impact of Limited Resources --- p.87 / Chapter 8.1.4 --- Impact of Multiple Resources --- p.89 / Chapter 8.1.5 --- Impact of Transaction Type --- p.95 / Chapter 8.1.6 --- Impact of Concurrency Control Overhead --- p.96 / Chapter 8.2 --- Exploiting Context-Specific Information --- p.98 / Chapter 8.2.1 --- Impact of Limited Resource --- p.98 / Chapter 8.2.2 --- Impact of Infinite and Multiple Resources --- p.101 / Chapter 8.2.3 --- Impact of Transaction Length --- p.106 / Chapter 8.2.4 --- Impact of Buffer Size --- p.108 / Chapter 8.2.5 --- Impact of Concurrency Control Overhead --- p.110 / Chapter 8.3 --- Summary and Discussion --- p.113 / Chapter 8.3.1 --- Summary of Results --- p.113 / Chapter 8.3.2 --- Relaxing Correctness Criterion vs. Exploiting Context-Specific In- formation --- p.114 / Chapter 9 --- Conclusions --- p.116 / Bibliography --- p.122 / Chapter A --- Commutativity Tables for Queue Objects --- p.128 / Chapter B --- Specification of a Queue Object --- p.129 / Chapter C --- Commutativity Tables with Bounded Inconsistency for Queue Objects --- p.132 / Chapter D --- Some Implementation Issues --- p.134 / Chapter D.1 --- Important Data Structures --- p.134 / Chapter D.2 --- Conflict Checking --- p.136 / Chapter D.3 --- Deadlock Detection --- p.137 / Chapter E --- Simulation Results --- p.139 / Chapter E.l --- Impact of Infinite Resources (Bounded Inconsistency) --- p.140 / Chapter E.2 --- Impact of Multiple Resource (Bounded Inconsistency) --- p.141 / Chapter E.3 --- Impact of Transaction Type (Bounded Inconsistency) --- p.142 / Chapter E.4 --- Impact of Concurrency Control Overhead (Bounded Inconsistency) --- p.144 / Chapter E.4.1 --- Infinite Resources --- p.144 / Chapter E.4.2 --- Limited Resource --- p.146 / Chapter E.5 --- Impact of Resource Levels (Exploiting Context-Specific Information) --- p.149 / Chapter E.6 --- Impact of Buffer Size (Exploiting Context-Specific Information) --- p.150 / Chapter E.7 --- Impact of Concurrency Control Overhead (Exploiting Context-Specific In- formation) --- p.155 / Chapter E.7.1 --- Impact of Infinite Resources --- p.155 / Chapter E.7.2 --- Impact of Limited Resources --- p.157 / Chapter E.7.3 --- Impact of Transaction Length --- p.160 / Chapter E.7.4 --- Role of Conflict Ratio --- p.162

Data warehousing is becoming an increasingly important technology for information integration and data analysis. Given the dynamic nature of modern distributed environments, both source data updates and schema changes are likely to occur autonomously and even concurrently in different data sources. Current approaches to maintain a data warehouse in such dynamic environments sequentially schedule maintenance processes to occur in isolation. Furthermore, each maintenance process is handling the maintenance of one single source update. This limits the performance of current data warehouse maintenance systems in a distributed environment where the maintenance of source updates endures the overhead of network delay as well as IO costs for each maintenance query. In this thesis work, we propose two different optimization strategies which can greatly improve data warehouse maintenance performance for a set of source updates in such dynamic environments. Both strategies are able to support source data updates and schema changes. The first strategy, the parallel data warehouse maintainer, schedules multiple maintenance processes concurrently. Based on the DWMS_Transaction model, we formalize the constraints that exist in maintaining data and schema changes concurrently and propose several parallel maintenance process schedulers. The second strategy, the batch data warehouse maintainer, groups multiple source updates and then maintains them within one maintenance process. We propose a technique for compacting the initial sequence of updates, and then for generating delta changes for each source. We also propose an algorithm to adapt/maintain the data warehouse extent using these delta changes. A further optimization of the algorithm also is applied using shared queries in the maintenance process. We have designed and implemented both optimization strategies and incorporated them into the existing DyDa/TxnWrap system. We have conducted extensive experiments on both the parallel as well as the batch processing of a set of source updates to study the performance achievable under various system settings. Our findings include that our parallel maintenance gains around 40 ~ 50% performance improvement compared to sequential processing in environments that use single-CPU machines and little network delay, i.e, without requiring any additional hardware resources. While for batch processing, an improvement of 400 ~ 500% improvement compared with sequential maintenance is achieved, however at the cost of less frequent refreshes of the data warehouse content.

This diploma thesis is aimed at programming of multithreaded applications in Java. With Java 5 comes package java.util.concurrent, which in an important way makes developing of parallel applications easier and more effective. This work is conceived as an introduction to programming of multithreaded applications in Java and could be also used as an educational material. Theoretical introduction about processes and technological background of multitasking gives analogy to threads, at the same time it is touching on Java technology and how Java works with memory. The rest of this diploma thesis concerns practical work with threads. This topic is covered from absolute beginning, which means creating Thread objects, including advanced topics like working with package java.util.concurrent and also some problems that can appear when writing multithreaded applications.

Fördelarna med ett digitalt och gränslöst arbetsliv är många, exempelvis är vi inte bundna till en specifik fysisk arbetsplats. Men det finns också gott om forskning som beskriver hur ett digitalt och gränslöst arbete påverkar oss människor negativt i form av skadlig stress. Däremot finns få förslag på förbättringar på området. Studien syftar till att – ett år senare – göra en uppföljning av ett program för en sund digital arbetsmiljö på ett mindre företag. Det studerade företagets medarbetare genomgick programmet i tre veckor och resultatet var mycket positivt – de kände sig mindre stressade och mer effektiva efter organisationsförändringen. Studiens frågeställningar är: Har organisationsförändringen hållit i sig? Varför? Varför inte? För att undersöka detta fick de som deltog i organisationsförändringen svara på en webbenkät. Utöver det genomfördes en intervju med företagets vd. Studien grundar sig på teorier om organisationsförändringar, stress i ett gränslöst arbetsliv samt hjärnforskning kopplad till förändringsprocesser och digital arbetsmiljö. Ingen tidigare forskning har hittats kring hur insatser för att hantera negativa aspekter av den digitala arbetsmiljön fungerar över tid. Studien visar att programmet för en sund digital arbetsmiljö har varit ett lyckat koncept på det specifika företaget, som delvis har hållit över tid. Medarbetarna jobbar ett år senare i relativt stor utsträckning enligt programmet för en sund digital arbetsmiljö. De delar av programmet som har varit lättast att hålla fast vid är de som handlar om att inte störa kollegorna, som att ha mobilen på ljudlöst i kontorslandskapet. Svårare har det varit att hålla fast vid de delar som handlar om att inte störa sig själv, som att läsa mail och sms på fasta tider. Resultatet pekar på att regler/policies för hur man ska hantera en digital arbetsmiljö samt ett starkt ledarskap är avgörande för att en hållbar sund digital arbetsmiljö. Även individen har ett ansvar.

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Main topic of this thesis is Win32 application programming interface and symbolic instructions programming language. It can be divided into four parts. First part sums the basics of 32-bit programming in symbolic instructions language in Windows. Second part describes the Win32 resources for computer intercommunication. Third part presents, describes and comments selected problems in symbolic instructions language.Last part covers a creation of an example application. This application and its parts will be the content of computer exercises in VUT Brno FEEC subject Počítače a jejich periferie.