In this paper,potential use of perfect but delayed channel estimates for variable-power discrete-rate adaptive modulation is explored.Research is concentrated on block by block adaptation.At first,a new quantity-TAUD(...In this paper,potential use of perfect but delayed channel estimates for variable-power discrete-rate adaptive modulation is explored.Research is concentrated on block by block adaptation.At first,a new quantity-TAUD(Tolerable Average Use Delay)is defined,it quantifies the performance of an adaptation scheme in tolerating the delay of channel estimates.Then,the research on TAUD shows that the delay tolerating performance declines with the increase in average power,the scheme working with more modulation modes can tolerate a longer delay,and such improvement will be more significant with the increase of average power.Finally,it shows that,as the delay tolerating performance determines the maximum block length,it has a great effect on the maximum spectral efficiency.The criterion for determining the block length appropriate for the target BER is described and a simple method of calculating the maximum block length is presented.展开更多
We sttidy the problem of scheduling n jobs on m parallel bounded batch machines to minimize the sum of squared machine loads. Each batch contains at most B jobs, and the processing time of a batch is equal to the long...We sttidy the problem of scheduling n jobs on m parallel bounded batch machines to minimize the sum of squared machine loads. Each batch contains at most B jobs, and the processing time of a batch is equal to the longest processing time of the jobs in this batch. We prove this problem to be NP-hard. Furthermore, we present a polynomial time approximation scheme （PTAS） and a fully polynomial time approximation scheme （FPTAS） for this problem.展开更多
This study was based on a descriptive research design. The population comprised of males and females aged between 15 and 19 years studying at the high school, college, and university levels in Phetchaburi, Thailand. T...This study was based on a descriptive research design. The population comprised of males and females aged between 15 and 19 years studying at the high school, college, and university levels in Phetchaburi, Thailand. The sample group size was calculated by using Taro Yamane＇s formula at a reliability level of .95. The instrument used was the questionnaire of College of Public Health as modified by Chulalongkorn University for use in research. Instrument quality was calculated by using the Kuder-Richardson 20 formula; an internal consistency value of.86 was obtained. According to the findings, the comparison of access to reproductive health services by adolescents at each level of education, the educational levels of the adolescents were similar to one another in that they were found to have received instruction about sexuality and reproductive health. The instruction most frequently received was on reproductive health and the least frequent subject was life skills, ability to adjust to daily lifestyles. The findings suggested that the capacity of medical and academic personnel should be developed in order to gain knowledge, attitudes to provide reproductive health services, especially on subjects concerning life skills and ability to adjust to daily life and interacting with the people surrounding adolescents, including skills on how to refuse sexual activity with partners.展开更多
基金supported by National Natural Science Foundation of China(No.61071087)Chun Lei 2009BWZ037 from SDUST,China
文摘In this paper,potential use of perfect but delayed channel estimates for variable-power discrete-rate adaptive modulation is explored.Research is concentrated on block by block adaptation.At first,a new quantity-TAUD(Tolerable Average Use Delay)is defined,it quantifies the performance of an adaptation scheme in tolerating the delay of channel estimates.Then,the research on TAUD shows that the delay tolerating performance declines with the increase in average power,the scheme working with more modulation modes can tolerate a longer delay,and such improvement will be more significant with the increase of average power.Finally,it shows that,as the delay tolerating performance determines the maximum block length,it has a great effect on the maximum spectral efficiency.The criterion for determining the block length appropriate for the target BER is described and a simple method of calculating the maximum block length is presented.
文摘We sttidy the problem of scheduling n jobs on m parallel bounded batch machines to minimize the sum of squared machine loads. Each batch contains at most B jobs, and the processing time of a batch is equal to the longest processing time of the jobs in this batch. We prove this problem to be NP-hard. Furthermore, we present a polynomial time approximation scheme （PTAS） and a fully polynomial time approximation scheme （FPTAS） for this problem.
文摘This study was based on a descriptive research design. The population comprised of males and females aged between 15 and 19 years studying at the high school, college, and university levels in Phetchaburi, Thailand. The sample group size was calculated by using Taro Yamane＇s formula at a reliability level of .95. The instrument used was the questionnaire of College of Public Health as modified by Chulalongkorn University for use in research. Instrument quality was calculated by using the Kuder-Richardson 20 formula; an internal consistency value of.86 was obtained. According to the findings, the comparison of access to reproductive health services by adolescents at each level of education, the educational levels of the adolescents were similar to one another in that they were found to have received instruction about sexuality and reproductive health. The instruction most frequently received was on reproductive health and the least frequent subject was life skills, ability to adjust to daily lifestyles. The findings suggested that the capacity of medical and academic personnel should be developed in order to gain knowledge, attitudes to provide reproductive health services, especially on subjects concerning life skills and ability to adjust to daily life and interacting with the people surrounding adolescents, including skills on how to refuse sexual activity with partners.
