1,371 research outputs found
VLSI single-chip (255,223) Reed-Solomon encoder with interleaver
The invention relates to a concatenated Reed-Solomon/convolutional encoding system consisting of a Reed-Solomon outer code and a convolutional inner code for downlink telemetry in space missions, and more particularly to a Reed-Solomon encoder with programmable interleaving of the information symbols and code correction symbols to combat error bursts in the Viterbi decoder
Training programs and implementation process of positive youth development programs
Editorialpublished_or_final_versio
Advances in adolescent research in the Chinese culture: Reflections and future research directions
Editorialpublished_or_final_versio
General Education Learning Outcomes and Demographic Correlates in University Students in Hong Kong
Although there are studies showing that higher education would benefit university students, empirical research that comprehensively assesses student general education learning outcomes and related demographic correlates based on longitudinal data is minimal, especially in the Chinese context. To address the research gaps, the present study was conducted to investigate learning outcomes amongst university students in one university in Hong Kong based on a four-year longitudinal design (N = 460). Four dimensions of student general education learning outcomes were measured, including effective reasoning and problem solving, leadership, moral character, and integration of learning. Results suggested a U-shaped pattern of student learning outcomes for most dimensions, with no improvement or even a decrement in the second year and a steady growth thereafter. While family background did not affect student development, gender showed a significant moderating effect on students’ development in two dimensions (i.e., effective reasoning and problem solving, and integration of learning). These findings suggest that students benefit from general education-embedded university study in multiple dimensions, especially after the first year of transition period. Practical implications of the findings and future research directions were also discussed
Development of a Condition Monitoring System for an Articulated Wave Energy Converter
ESREL 2016: European Safety and Reliability Conference 2016, Glasgow, UK, 25-29 September, 2016This is the author accepted manuscript. The final version is available from the publisher.Condition monitoring systems (CMS) in renewable energy devices allow for the detection of oncoming faults, providing data to undertake pre-emptive maintenance. By defining a systems functional re-quirements and identifying of critical failure modes, proactive maintenance strategies to be produced. The lack of operational data in the marine energy industry, and lack of consensus in operating principles between devic-es, means that a non-standardised CMS package is available for wave energy converters (WECs). In this study a Failure Modes and Effects Analysis (FMEA) is undertaken in order to identify the critical failure modes of an articulated WEC, measurement priorities are identified and a set of monitoring solutions provided. Installing a CMS provides the framework for collecting quality component reliability data, however further development is required for building a proactive maintenance strategy and for continuous reliability improvement
Control and Instrumentation Topologies for an Integrated Wave Energy Array
SubmittedControl and Instrumentation (C&I) systems provide the framework for monitoring critical data streams and implementing control functions during the operation of a wave energy converter. However, cost and power constraints of wave energy converters present a challenge in designing a C&I architecture that is appropriate for the application. This study describes the design of a C&I system for an integrated wave en-ergy array. A specification is first developed by defining operational requirements and design principles, measurement and control priorities are then identified, incorporating a failure mode and effects analysis. Available instrumentation options in the industry are reviewed and C&I topologies are presented. A distribut-ed control system is proposed for the Albatern WaveNET Array, allowing for the implementation of control and protection strategies and condition monitoring. Improved C&I allows for the reduction of unplanned maintenance, maximising device availability for energy production.The author would like to thank the industrial and academic supervisors, in addition to many industrial representatives whom provided valuable input to this paper. The support of the ETI and RCUK Energy Programme funding for IDCORE (EP/J500847/1) is gratefully acknowledged
Lessons Learned from 3 Years of Failure: Validating an FMEA with Historical Failure Data
This is the author accepted manuscript. The final version is available from EWTEC via the link in this record.Device reliability is often considered essential to the performance of a wave energy converter. Developers may undertake a Failure Mode and Effects Analysis (FMEA) as a design process to evaluate the high priority failure modes of a prototype to approximate device reliability. However, failures identified by this process are typically predicted, and often lack validation from actual marine operations history. In view of this, an FMEA undertaken for the Albatern Squid 6 Series Wave Energy Converter (WEC) has been validated using historical failure rate and marine operations data. Results indicate that a high volume of major structural and hydraulic failures occurred in the initial stages of deployment, whilst minor electrical and instrumentation failures occurred towards the latter. A notable observation is that human driven failures constituted a much larger portion of failure occurrences than the FMEA predicted. As a general observation, the retrospective analysis of failure rate requires consistent data recording procedures, especially given the introduction of new innovations, which may cause a resurgence of early-stage faults. Lessons learned in the operation of a redundant, modular and accessible array are discussed in the view of designing devices that are not immune, but resilient to failure.The author gratefully acknowledges the support of the ETI and RCUK Energy Programme funding for IDCORE (EP/J500847/1), and the support of Wave Energy Scotland during the installation and commissioning of the Mingary Bay wave array
Positive Youth Development, Life Satisfaction and Problem Behaviour Among Chinese Adolescents in Hong Kong: A Replication
The purpose of this replication study was to examine the relationships among life satisfaction, positive youth development and problem behaviour. The respondents were 7,151 Chinese Secondary 2 (Grade 8) students (3,707 boys and 3,014 girls) recruited from 44 schools in Hong Kong. Validated assessment tools measuring positive youth development, life satisfaction and problem behaviour were used. As predicted, positive youth development was positively correlated with life satisfaction, and positive youth development and life satisfaction were negatively correlated with adolescent problem behaviour. Based on a series of structural equation models, the present findings replicated the previous findings that adolescents with a higher level of positive youth development were more satisfied with life and had lesser problem behaviour, with higher level of life satisfaction and lower level of problem behaviour mutually influencing each other. These replicated findings provide a further advance in the literature on positive youth development, particularly in the Chinese context. Implications for future research and intervention were discussed
Free-Boundary Dynamics in Elasto-plastic Amorphous Solids: The Circular Hole Problem
We develop an athermal shear-transformation-zone (STZ) theory of plastic
deformation in spatially inhomogeneous, amorphous solids. Our ultimate goal is
to describe the dynamics of the boundaries of voids or cracks in such systems
when they are subjected to remote, time-dependent tractions. The theory is
illustrated here for the case of a circular hole in an infinite two-dimensional
plate, a highly symmetric situation that allows us to solve much of the problem
analytically. In spite of its special symmetry, this example contains many
general features of systems in which stress is concentrated near free
boundaries and deforms them irreversibly. We depart from conventional
treatments of such problems in two ways. First, the STZ analysis allows us to
keep track of spatially heterogeneous, internal state variables such as the
effective disorder temperature, which determines plastic response to subsequent
loading. Second, we subject the system to stress pulses of finite duration, and
therefore are able to observe elasto-plastic response during both loading and
unloading. We compute the final deformations and residual stresses produced by
these stress pulses. Looking toward more general applications of these results,
we examine the possibility of constructing a boundary-layer theory that might
be useful in less symmetric situations.Comment: 30 pages (preprint format), 9 figure
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