873 research outputs found
Multi-Carrier and Spread Spectrum Systems
No full textTable of Contents Multi-Carrier and Spread Spectrum Systems describes and analyses the basic concepts of the combination of multi-carrier transmission with spread spectrum (MC-SS). The various architectures and the different detection strategies are examined in some depth. Techniques for capacity and flexibility enhancement of multi-carrier systems such as diversity techniques and space-time/frequency coding (STC, STFC) are also analysed. Since 1993 different multiple access concepts based on the MC-SS combination for mobile and wireless indoor communications called OFDM/CDMA or MC-CDMA and MC-DS-CDMA, have been proposed. The main differences between these schemes are in the spreading, frequency mapping, and detection strategies. Meanwhile, other alternative hybrid schemes such as OFDM/OFDMA, MC-TDMA, etc. have been deeply studied that benefit from the advantages of multi-carrier transmission. This book: · Covers multi-carrier and spread spectrum and all derivatives of spread spectrum and OFDM systems. · Describes not only HIPERLAN but also wireless multi-user systems dealing with OFDM or spread spectrum techniques: 2G IS-95, 3G UMTS, and 4th Generation mobile communications. · Provides significant analysis on multi-carrier transmission, from theory to practical implementations and is therefore invaluable for systems designers. · Examines the essentials of all wireless standards based on multi-carrier/spread spectrum technique. Written in a highly accessible manner this book will provide a unique reference on the topic of multi-carrier spread spectrum, assisting 4G engineers for their implementation
Die noodsaak van Skrifgefundeerde vaderskap as antwoord op die voortslepende probleem van vaderafwesigheid in Suid-Afrika
No full textThe absence of any parent in a family system causes a vacuum with respect to the parenting role and it affects the family's ability to function effectively. In the South African context father absence is on the increase and it frequently generates problems such as broken families, undesirable and aggressive behaviour among children, single parenting, financial and social problems as well as poverty. The role of the father and his physical presence are of utmost importance in the life of children because his fatherhood role contributes to the child's cognitive development and intellectual functioning. The author views this problem of father absence as a matter of seriousness and concern, thus the cry for the Bible as a possible solution. In this article it appears and becomes clear that a Sola Scriptura policy is being used. The article therefore focuses on Biblical truth and departure points from literature to highlight the importance of fatherhood. Scripture is not just an authoritative source of teaching, correction and admonition but also serves as an exceptional guideline and measure that speak of the uniqueness of God as Father, while presenting answers regarding the worth of an earthly father within a family system. OPSOMMING: In enige gesinsisteem veroorsaak die afwesigheid van 'n ouer 'n vakuum in die ouerskapsrol en die gesin se vermoë om doeltreffend te funksioneer word nadelig geaffekteer. Vaderafwesigheid in die Suid-Afrikaanse konteks is aan die toeneem en veroorsaak dikwels probleme soos gebroke gesinne, ongewenste en aggressiewe gedrag onder kinders, enkelouerskap, finansiële, sosiale en maatskaplike probleme asook armoede. In die gesin is die rol van 'n vader en sy fisiese teenwoordigheid van kardinale belang vir kinders omrede sy vaderskapsrol bydra tot die kognitiewe ontwikkeling en die intellektuele funksionering van die kind. Die skrywer beskou hierdie probleem van vaderafwesigheid as 'n saak van erns en bekommernis en daarom die hulpgeroep na die Skrif as moontlike oplossing. Dit blyk duidelik te wees dat in hierdie artikel van 'n Sola Scriptura-beleid gebruik gemaak word. Die artikel fokus dus op Bybelse waarhede en vertrekpunte uit die literatuur om die belangrikheid van vaderskap uit te lig. Die Skrif is nie net 'n gesaghebbende bron vir onderrig, teregwysing en vermaning nie, maar is ook 'n uitsonderlike riglyn en maatstaf wat insig gee in die uniekheid van God as Vader en wat antwoorde bied oor die waarde van 'n aardse vader binne 'n gesinsisteem
Git-based platform for distributed learning communities
No full textThesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 67-69).Instructors use software called learning management systems to administer online courses. Traditionally these digital platforms mimic physical classrooms, but technology opens up potential for new types of interactions. In this thesis, we develop a learning management system on top of Git to create a learning environment that encourages collaboration and exploration. We discuss how it was designed, the underlying pedagogy, the technical implementation, and the results of a pilot online class, with 100 learners lasting 6 weeks. The platform architecture developed in this project can be replicated and reused for other online courses with similar goals.by Vahid Fazel-Rezai.M. Eng
Cognitive styles and psychological functioning in rural South African school students: Understanding influences for risk and resilience in the face of chronic adversity
No full textAdverse childhood experiences can show lasting effects on physical and mental health. Major questions surround how children overcome adverse circumstances to prevent negative outcomes. A key factor determining resilience is likely to be cognitive interpretation (how children interpret the world around them). The cognitive interpretations of 1025 school children aged 10-12 years in a rural, socioeconomically disadvantaged area of South Africa were examined using the Cognitive Triad Inventory for Children (CTI-C). These were examined in relation to psychological functioning and perceptions of the school environment. Those with more positive cognitive interpretations had better psychological functioning on scales of depression, anxiety, somatization and sequelae of potentially traumatic events. Children with more negative cognitions viewed the school-environment more negatively. Children living in poverty in rural South Africa experience considerable adversity and those with negative cognitions are at risk for psychological problems. Targeting children's cognitive interpretations may be a possible area for intervention
sj-pdf-2-cmx-10.1177_10775595221079308 - Supplemental Material for Leveraging Administrative Data to Better Understand and Address Child Maltreatment: A Scoping Review of Data Linkage Studies
No full textSupplemental Material, sj-pdf-2-cmx-10.1177_10775595221079308 for Leveraging Administrative Data to Better Understand and Address Child Maltreatment: A Scoping Review of Data Linkage Studies by Emma Soneson, Shruti Das, Anne-Marie Burn, Marije van Melle, Joanna K. Anderson, Mina Fazel, Peter Fonagy, Tamsin Ford, Ruth Gilbert, Katie Harron, Emma Howarth, Ayla Humphrey, Peter B. Jones, and Anna Moore in Child Maltreatment</p
sj-pdf-1-cmx-10.1177_10775595221079308 - Supplemental Material for Leveraging Administrative Data to Better Understand and Address Child Maltreatment: A Scoping Review of Data Linkage Studies
No full textSupplemental Material, sj-pdf-1-cmx-10.1177_10775595221079308 for Leveraging Administrative Data to Better Understand and Address Child Maltreatment: A Scoping Review of Data Linkage Studies by Emma Soneson, Shruti Das, Anne-Marie Burn, Marije van Melle, Joanna K. Anderson, Mina Fazel, Peter Fonagy, Tamsin Ford, Ruth Gilbert, Katie Harron, Emma Howarth, Ayla Humphrey, Peter B. Jones, and Anna Moore in Child Maltreatment</p
Interleaved FDMA - A New Spread-Spectrum Multiple-Access Scheme
No full textA new spread-spectrum multiple-access scheme applicable for both the uplink and the downlink of a mobile radio communications system is proposed, which is termed "interleaved frequency-division multiple-access". This scheme combines the advantages of spread-spectrum and multicarrier transmission. Moreover, it can be viewed as a special kind of a multicarrier spread-spectrum scheme where user discrimination is carried out using frequency-division multiple-access. The multiple-access capability is achieved by assigning to each user a different set of orthogonal subcarriers. The orthogonality between the different users is maintained at the receiver, even in time-dispersive channels resulting in no multiple-access interference. However, the cost to avoid multiple-access interference is to allow for intersymbol interference and therefore equalization is required at the receiver
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