title: A power sharing series power BJT array with isolated low voltage control for AC power control applications

authors: Kularatna, Nihal

subjects: AC power control

abstract: A technique for a continuously variable AC resistance using a series BJT array is presented. This array provides high power dissipation capability and uniform voltage and power distribution across the individual transistors. The array, controlled using a set of optoisolators to maintain the electrical isolation between the control circuits and the power stage, could be used as the basis to develop several useful techniques including a solid state AC regulator with comparable performance to the commonly used ferro-resonant systems; a linear AC electronic load suitable for testing UPS and other power conditioners; and, in other AC power control applications such as switching capacitors in AC resonant circuits.

text: A power sharing series power BJT array with isolated low voltage control for AC power control applications A technique for a continuously variable AC resistance using a series BJT array is presented. This array provides high power dissipation capability and uniform voltage and power distribution across the individual transistors. The array, controlled using a set of optoisolators to maintain the electrical isolation between the control circuits and the power stage, could be used as the basis to develop several useful techniques including a solid state AC regulator with comparable performance to the commonly used ferro-resonant systems; a linear AC electronic load suitable for testing UPS and other power conditioners; and, in other AC power control applications such as switching capacitors in AC resonant circuits.

year: 2006

title: Development of the athlete sleep behavior questionnaire: A tool for identifying maladaptive sleep practices in elite athletes

authors: Driller, Matthew W.

subjects: Surveys and Questionnaires

abstract: INTRODUCTION: Existing sleep questionnaires to assess sleep behaviors may not be sensitive in determining the unique sleep challenges faced by elite athletes. The purpose of the current study was to develop and validate the Athlete Sleep Behavior Questionnaire (ASBQ) to be used as a practical tool for support staff working with elite athletes. 
METHODS: 564 participants (242 athletes, 322 non-athletes) completed the 18-item ASBQ and three previously validated questionnaires; the Sleep Hygiene Index (SHI), the Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI). A cohort of the studied population performed the ASBQ twice in one week to assess test-retest reliability, and also performed sleep monitoring via wrist-actigraphy. 
RESULTS: Comparison of the ASBQ with existing sleep questionnaires resulted in moderate to large correlations (r=0.32 - 0.69). There was a significant difference between athletes and non-athletes for the ASBQ global score (44±6 vs. 41±6, respectively, p<0.01) and for the PSQI, but not for the SHI or the ESS. The reliability of the ASBQ was acceptable (ICC=0.87) when re-tested within 7 days. There was a moderate relationship between ASBQ and total sleep time (r=-0.42). 
CONCLUSION: The ASBQ is a valid and reliable tool that can differentiate the sleep practices between athletes and non-athletes, and offers a practical instrument for practitioners and/or researchers wanting to evaluate the sleep behaviors of elite athletes. The ASBQ may provide information on areas where improvements to individual athletes' sleep habits could be made.

text: Development of the athlete sleep behavior questionnaire: A tool for identifying maladaptive sleep practices in elite athletes INTRODUCTION: Existing sleep questionnaires to assess sleep behaviors may not be sensitive in determining the unique sleep challenges faced by elite athletes. The purpose of the current study was to develop and validate the Athlete Sleep Behavior Questionnaire (ASBQ) to be used as a practical tool for support staff working with elite athletes. 
METHODS: 564 participants (242 athletes, 322 non-athletes) completed the 18-item ASBQ and three previously validated questionnaires; the Sleep Hygiene Index (SHI), the Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI). A cohort of the studied population performed the ASBQ twice in one week to assess test-retest reliability, and also performed sleep monitoring via wrist-actigraphy. 
RESULTS: Comparison of the ASBQ with existing sleep questionnaires resulted in moderate to large correlations (r=0.32 - 0.69). There was a significant difference between athletes and non-athletes for the ASBQ global score (44±6 vs. 41±6, respectively, p<0.01) and for the PSQI, but not for the SHI or the ESS. The reliability of the ASBQ was acceptable (ICC=0.87) when re-tested within 7 days. There was a moderate relationship between ASBQ and total sleep time (r=-0.42). 
CONCLUSION: The ASBQ is a valid and reliable tool that can differentiate the sleep practices between athletes and non-athletes, and offers a practical instrument for practitioners and/or researchers wanting to evaluate the sleep behaviors of elite athletes. The ASBQ may provide information on areas where improvements to individual athletes' sleep habits could be made.

year: 2018

title: Creating culturally-safe schools for Māori students

authors: Macfarlane, Angus

subjects: education

abstract: In order to better understand the present trends in New Zealand’s schooling contexts, there is a clarion call for educators to develop sensitivity and sensibility towards the cultural backgrounds and experiences of Māori students. This paper reports on the work of four scholars who share research that has been undertaken in educational settings with high numbers of Māori students, and discusses the importance of creating culturally-safe schools – places that allow and enable students to be who and what they are. The theoretical frameworks drawn on are based on both a life partnership analogy as well as on a socio-cultural perspective on human development and learning. The Māori worldview presented in this paper is connected to the Treaty of Waitangi, The Educultural Wheel and the Hikairo Rationale. Data were collected from two ethnographic case studies and analysed through these frameworks. Practical suggestions are then made for using restorative practices and creating reciprocal relationships in classrooms within an environment of care. The paper reports on an evidence-based approach to creating culturally-safe schools for Māori students.

text: Creating culturally-safe schools for Māori students In order to better understand the present trends in New Zealand’s schooling contexts, there is a clarion call for educators to develop sensitivity and sensibility towards the cultural backgrounds and experiences of Māori students. This paper reports on the work of four scholars who share research that has been undertaken in educational settings with high numbers of Māori students, and discusses the importance of creating culturally-safe schools – places that allow and enable students to be who and what they are. The theoretical frameworks drawn on are based on both a life partnership analogy as well as on a socio-cultural perspective on human development and learning. The Māori worldview presented in this paper is connected to the Treaty of Waitangi, The Educultural Wheel and the Hikairo Rationale. Data were collected from two ethnographic case studies and analysed through these frameworks. Practical suggestions are then made for using restorative practices and creating reciprocal relationships in classrooms within an environment of care. The paper reports on an evidence-based approach to creating culturally-safe schools for Māori students.

year: 2007