70 research outputs found
UWB FMCW Radar for Concealed Weapon Detection: RF front-end development
No full textCurrent methods for concealed weapon detection are mainly used at stationary security check-points due to complexity and other serious limitations for real-time outdoor scenarios. A mobile imaging radar is considered as a proper solution for fast screening of people at mass events because of its ability to detect both metal and non-metal weapons through clothes. In this thesis, the design of an RF front-end for an UWB Microwave Imaging Radar based on MIMO 2-D array and multichannel FMCW electronics is presented. Requirements to the design were low power emissions and minimization of data acquisition time, cost and complexity. The UWB technology provides high resolution, while MIMO technique helps reducing the number of required antennas in the 2-D array, without a net degradation of performance. The final RF-scheme was selected based on the availability of commercial off-the-shelves RF-components. The performance of the designed RF front-end was evaluated both via theoretical analysis and simulations in a dedicated software Advanced Design System (ADS, by Agilent). The obtained results in terms of sensitivity, dynamic range, down-range resolution and measurement speed demonstrate that the proposed solution is feasible for through-dress detection of concealed weapons.Microwave Technology and Systems for RadarTelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
Analyzing Social Experiments as Implemented: A Reexamination of the Evidence From the HighScope Perry Preschool Program
No full textSocial experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. "Signicant" effects are often reported with p-values that do not account for preliminary screening from a large candidate pool of possible effects. This paper develops tools for analyzing data from experiments as they are actually implemented. We apply these tools to analyze the influential HighScope Perry Preschool Program. The Perry program was a social experiment that provided preschool education and home visits to disadvantaged children during their preschool years. It was evaluated by the method of random assignment. Both treatments and controls have been followed from age 3 through age 40. Previous analyses of the Perry data assume that the planned randomization protocol was implemented. In fact, as in many social experiments, the intended randomization protocol was compromised. Accounting for compromised randomization, multiple-hypothesis testing, and small sample sizes, we find statistically significant and economically important program effects for both males and females. We also examine the representativeness of the Perry study.early childhood intervention; compromised randomization; social experiment; multiple-hypothesis testing
Analyzing Social Experiments as Implemented: A Reexamination of the Evidence From the HighScope Perry Preschool Program
No full textSocial experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. "Significant" effects are often reported with p-values that do not account for preliminary screening from a large candidate pool of possible effects. This paper develops tools for analyzing data from experiments as they are actually implemented. We apply these tools to analyze the influential HighScope Perry Preschool Program. The Perry program was a social experiment that provided preschool education and home visits to disadvantaged children during their preschool years. It was evaluated by the method of random assignment. Both treatments and controls have been followed from age 3 through age 40. Previous analyses of the Perry data assume that the planned randomization protocol was implemented. In fact, as in many social experiments, the intended randomization protocol was compromised. Accounting for compromised randomization, multiple-hypothesis testing, and small sample sizes, we find statistically significant and economically important program effects for both males and females. We also examine the representativeness of the Perry study.
3D imaging by fast deconvolution algorithm in short-range UWB radar for concealed weapon detection
No full textA fast imaging algorithm for real-time use in short-range (ultra-wideband) radar with synthetic or real-array aperture is proposed. The reflected field is presented here as a convolution of the target reflectivity and point spread function (PSF) of the imaging system. To obtain a focused 3D image, the proposed algorithm deconvolves the PSF out from the acquired data volume with high speed due to fast Fourier transform and implementation in frequency-wavenumber domain. Then the result is tested against two numerical criteria for efficiency, namely error and instability, whose optimal values can be obtained iteratively. Since the PSF differs with distance, the algorithm suits mainly applications with relatively small objects such as concealed weapon detection. Using several PSFs allows us to image a certain range of interest by their successive deconvolution from the same data. Performance of the algorithm has been evaluated experimentally and compared with that of Kirchhoff migration. Measurements were carried out by a 5–25 GHz synthetic aperture radar in the lab, and scenarios included a gun and a ceramic knife in free space, on a large metal plate, and a gun concealed on a dummy under a thick raincoat. The results demonstrate sufficient image quality obtained in a fraction of time.Electrical Engineering, Mathematics and Computer Scienc
Analyzing Social Experiments as Implemented: A Reexamination of the Evidence from the HighScope Perry Preschool Program
No full textSocial experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. "Significant" effects are often reported with p-values that do not account for preliminary screening from a large candidate pool of possible effects. This paper develops tools for analyzing data from experiments as they are actually implemented. We apply these tools to analyze the influential HighScope Perry Preschool Program. The Perry program was a social experiment that provided preschool education and home visits to disadvantaged children during their preschool years. It was evaluated by the method of random assignment. Both treatments and controls have been followed from age 3 through age 40. Previous analyses of the Perry data assume that the planned randomization protocol was implemented. In fact, as in many social experiments, the intended randomization protocol was compromised. Accounting for compromised randomization, multiple-hypothesis testing, and small sample sizes, we find statistically significant and economically important program effects for both males and females. We also examine the representativeness of the Perry study.social experiment, compromised randomization, early childhood intervention, multiple-hypothesis testing
Interactions Between an Education Polygenic Score and SES in Determining Health in Young Adulthood
No full textI find that an education polygenic score (PGS) and socioeconomic status (SES) are positively associated with health in young adulthood. I also explore the moderating role of SES and contribute to the discussion on the casual status of education as a determinant of health.EconomicsBachelors of Arts (BA
Conscientiousness, Extraversion, College Education, and Longevity of High-Ability Individuals
No full textUsing the 1922–1991 Terman Life-Cycle Study of Children with High Ability, I investigate the relationship between childhood noncognitive skills, college education, and longevity of a high-IQ population and find a strong relationship between college education and longevity for men. Conscientiousness and Extraversion are strongly related to longevity of men, even though their effects on education are, at best, weak. I demonstrate a number of behavioral mechanisms behind the estimated effects on longevity. I also find that men with higher levels of education and skills have superior health over the lifespan. For women of this historical cohort (born around 1910), who live at least as long as college-educated men, I find no evidence of a relationship between education, noncognitive skills, and longevity.Economic
Language Dispersal Beyond Farming
No full textWhy do some languages wither and die, while others prosper and spread? Around the turn of the millennium a number of archaeologists such as Colin Renfrew and Peter Bellwood made the controversial claim that many of the world’s major language families owe their dispersal to the adoption of agriculture by their early speakers. In this volume, their proposal is reassessed by linguists, investigating to what extent the economic dependence on plant cultivation really impacted language spread in various parts of the world. Special attention is paid to "tricky" language families such as Eskimo-Aleut, Quechua, Aymara, Bantu, Indo-European, Transeurasian, Turkic, Japano-Koreanic, Hmong-Mien and Trans-New Guinea, that cannot unequivocally be regarded as instances of Farming/Language Dispersal, even if subsistence played a role in their expansio
Language Dispersal Beyond Farming
No full textWhy do some languages wither and die, while others prosper and spread? Around the turn of the millennium a number of archaeologists such as Colin Renfrew and Peter Bellwood made the controversial claim that many of the world’s major language families owe their dispersal to the adoption of agriculture by their early speakers. In this volume, their proposal is reassessed by linguists, investigating to what extent the economic dependence on plant cultivation really impacted language spread in various parts of the world. Special attention is paid to "tricky" language families such as Eskimo-Aleut, Quechua, Aymara, Bantu, Indo-European, Transeurasian, Turkic, Japano-Koreanic, Hmong-Mien and Trans-New Guinea, that cannot unequivocally be regarded as instances of Farming/Language Dispersal, even if subsistence played a role in their expansio
Analyzing social experiments as implemented: evidence from the HighScope Perry Preschool Program
No full textSocial experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. "Significant" effects are often reported with p-values that do not account for preliminary screening from a large candidate pool of possible effects. This paper develops tools for analyzing data from experiments as they are actually implemented. We apply these tools to analyze the influential HighScope Perry Preschool Program. The Perry program was a social experiment that provided preschool education and home visits to disadvantaged children during their preschool years. It was evaluated by the method of random assignment. Both treatments and controls have been followed from age 3 through age 40. Previous analyses of the Perry data assume that the planned randomization protocol was implemented. In fact, as in many social experiments, the intended randomization protocol was compromised. Accounting for compromised randomization, multiple-hypothesis testing, and small sample sizes, we find statistically significant and economically important program effects for both males and females. We also examine the representativeness of the Perry study. Download appendix
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