Hand gesture recognition, prediction, and coding using hidden Markov models

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (leaves 56-57).by Katerina H. Nguyen.M.Eng

Victimisation, poly-victimisation and health-related quality of life among high school students in Vietnam: a cross-sectional survey

BACKGROUND: In high and upper-middle income countries poly-victimisation (exposure to multiple forms of victimisation) is associated with worse health-related quality of life (HRQoL) among adolescents. There is a lack of empirical evidence about these associations from low- and lower-middle income countries. The aims of this study were to examine the associations between exposure to 1) individual forms of victimisation and 2) poly-victimisation and the HRQoL of adolescents in Vietnam. METHOD: A cross-sectional, anonymously-completed survey of high school students in Hanoi, Vietnam. Lifetime exposure to eight individual forms of victimisation and poly-victimisation were assessed using the Juvenile Victimisation Questionnaire Revised-2 (JVQ R2). Health-related quality of life was assessed using the Duke Health Profile Adolescent Version (DHP-A). Bi-variate analyses and multiple linear regressions were conducted to assess the associations between individual forms of victimisation, poly-victimisation and HRQoL among girls and boys. RESULTS: In total 1616/1745 students (92.6 %) completed the questionnaire. Adolescent girls had significantly worse HRQoL than boys in all domains, except disability. Different forms of victimisation were associated with different HRQoL domains among girls and boys. Cyber victimisation was the most detrimental to girls\u27 HRQoL while for boys maltreatment was the most detrimental. Experiences of poly-victimisation were associated with worse HRQoL in physical, mental, social and general health, lower levels of self-esteem and increased levels of anxiety, depression and pain domains among both sexes. CONCLUSIONS: Among Vietnamese adolescents, experiences of individual forms of victimisation were associated with poorer HRQoL in specific domains; the most detrimental forms of victimisation varied for girls and boys. However, it was experiences of poly-victimisation that had the most detrimental impacts on the HRQoL of both sexes. Recognition of violence, including poly-victimisation, is still low in Vietnam. These data indicate that community education, prevention and early intervention programs to reduce violent victimisation and assist adolescents who have experienced it, with attention to gender differences, are needed in Vietnam

Poly-victimisation and health risk behaviours, symptoms of mental health problems and suicidal thoughts and plans among adolescents in Vietnam

BACKGROUND: Limited evidence is available about poly-victimisation (exposure to multiple forms of victimisation) and mental health among adolescents in low and lower-middle-income countries. The aim of this study was to examine the associations between lifetime exposure to poly-victimisation, health risk behaviours, symptoms of common mental health problems and suicidal ideas in the previous year among high school students in Vietnam. METHODS: Participants were high school students in rural and urban districts of Hanoi, Vietnam. The data source was an anonymously-completed structured self-report survey. Lifetime exposure to poly-victimisation was assessed using the juvenile victimisation questionnaire revised 2 (JVQ R-2); mental health symptoms by the depression, anxiety and stress scale-21 (DASS-21); involvement in health risk behaviours and previous year suicidal thoughts and plans by questions adapted from the 2013 youth risk behaviour survey. Data were collected between October, 2013 and January, 2014 and were analysed using generalised structural equation modelling. RESULTS: In total 1616/1745 (92.6 %) eligible students provided complete data. Prior year suicidal thoughts were reported by 21.4 % (95 % CI 18.5–24.5 %) of the female respondents and 7.9 % (95 % CI 6.2–9.8 %) of the male respondents. Prior year suicidal plans were reported by 7.8 % (95 % CI 5.9–9.8 %) of the girls and 4.0 % (95 % CI 2.7–5.3 %) of the boys. Poly-victimisation was associated with increased likelihood of involvement in health risk behaviours and symptoms of common mental health problems among both sexes, which increased adolescents’ risk of having suicidal ideas in the previous year. Compared to non-victims or victims of fewer forms, poly-victims were also more likely to report suicidal thoughts and plans among both girls and boys (p < 0.05). CONCLUSIONS: Overall, the results revealed that poly-victimisation was associated with increased involvement in health risk behaviours, poorer mental health and increased risks of suicidal ideas among Vietnamese adolescents. Suicidal ideas were prevalent among the students. Interventions to assist victims of violence and prevention of violence, especially poly-victimisation, among adolescents in Vietnam is therefore important

Theory of Luminescent Emission in Nanocrystal ZnS:Mn with an Extra Electron

We consider the effect of an extra electron injected into a doped quantum dot $ZnS:Mn^{2+}$. The Coulomb interaction and the exchange interaction between the extra electron and the states of the Mn ion will mix the wavefunctions, split the impurity energy levels, break the previous selection rules and change the transition probabilities. Using this model of an extra electron in the doped quantum dot, we calculated the energy and the wavefunctions, the luminescence probability and the transition lifetime and compare with the experiments. Our calculation shows that two orders of magnitudes of lifetime shortening can occur in the transition $^4T_1-^6A_1$ when an extra electron is present.Comment: 15 pages, 2 Figs No change in Fig