Stray light analysis of the Diffuse Infrared Background Experiment (DIRBE)

The straylight analysis of the diffuse infrared background experiment (DIRBE) on the cosmic background explorer (COBE) mission is discussed. From the statement of work (SOW), the purpose of DIRBE is to measure, or set upper limits on, the spectral and spatial character of the diffuse extra galactic infrared radiation. Diffuse infrared sources within our own galaxy are measured. The required reduction of the unwanted radiation imposes severe design and operating restrictions on the DIRBE instrument. To accomplish its missions, it will operate at a multitude of wavelengths ranging from 1.25 um out to 200 to 300 microns. The operating bands and the required point source normalized irradiance transmittance (PSNIT) are shown. The important straylight concepts in the DIRBE design are reviewed. The model and assumptions used in APART analysis are explained. The limitations due to the scalar theory used in the analysis are outlined

Stray light in the Infrared Astronomical Satellite (IRAS)

Changes made to the telescope and critical objects considered in modeling these changes into the APART program are described. The optical system was analyzed for scattered light, diffracted then scattered radiation, and thermally emitted radiation. The damaged area of the primary to mirror was also examined. Results are presented in tables and graphs

Infrared Astronomical Satellite (IRAS) analysis of the transmittance of off-axis energy due to scattering and diffraction

Stray light transmittance is analyzed. Mathematical models are evaluated. The results of scatter and diffraction are considered separately, and the combined transmittance values evaluated

Studi Performa Migrasi Ipv4 ke Ipv6 pada Metode Dual Stack

Dengan ketersedian (space) dari pengalamatan IPv4 yang telah sedikit, itu telah menjadi alasan utama bagi penyedia layanan, Perusahaan, pengembang aplikasi, dan pemerintah untuk memulai beralih dengan IPv6. Sebuah migrasi dari IPv4 ke IPv6 sulit dicapai. Karena beberapa mekanisme yang diperlukan untuk menjamin kelancaran, komunikasi dan peralihan secara utuh ke IPv6. Tidak hanya transisi, integrasi IPv6 juga diperlukan ke dalam jaringan yang ada. Solusi (mekanisme) dapat dibagi menjadi tiga kategori: dual stack, tunneling dan translation. Dalam proyek ini mekanisme tr ansisi Dual-Stack diimplementasikan di GNS3 (Graphical Network Simulator), menggunakan CISCO router. Jaringan ini dilihat dengan bantuan Wireshark (Packet analyzer). kedua topologi dibandingkan, Dual-Stack dan Tunneling, yang dapat diamati dengan menangkap paket pada interface router

Cluster Dynamics in a Circulating Fluidized Bed

A common hydrodynamic feature in industrial scale circulating fluidized beds is the presence of clusters. The continuous formation and destruction of clusters strongly influences particle hold-up, pressure drop, heat transfer at the wall, and mixing. In this paper fiber optic data is analyzed using discrete wavelet analysis to characterize the dynamic behavior of clusters. Five radial positions at three different axial locations under five different operating were analyzed using discrete wavelets. Results are summarized with respect to cluster size and frequency

Viability and Application of Mounting Personal PID VOC Sensors to Small Unmanned Aircraft Systems

Using a UAS-mounted sensor to allow for a rapid response to areas that may be difficult to reach or potentially dangerous to human health can increase the situational awareness of first responders of an aircraft crash site through the remote detection, identification, and quantification of airborne hazardous materials. The primary purpose of this research was to evaluate the remote sensing viability and application of integrating existing commercial-off-the-shelf (COTS) sensors with small unmanned aircraft system (UAS) technology to detect potentially hazardous airborne contaminants in emergency leak or spill response situations. By mounting the personal photoionization detector (PID) with volatile organic compound VOC sensor technology on UAS platforms, the needed information may be obtained at an optimum range and resolution without needlessly exposing a human to possible adverse conditions

Dynamical tests on fiber optic data taken from the riser section of a circulating fluidized bed

Dynamical tests have been applied to fiber optic data taken from a cold-flow circulating fluidized bed to characterize flow conditions, identify three time and/or length scales (macro, meso, and micro), and understand the contribution these scales have on the raw data. The characteristic variable analyzed is the raw voltage signal obtained from a fiber-optic probe taken at various axial and radial positions under different loading conditions so that different flow regimes could be attained. These experiments were carried out with the bed material of 812 μm cork particles. The characterization was accomplished through analysis of the distribution of the signal through the third and fourth moments of skewness and excess kurtosis. A generalization of the autocorrelation function known as the average mutual information function was analyzed by examining the function’s first minimum, identifying the point at which successive elements are no longer correlated. Further characterization was accomplished through the correlation dimension, a measure of the complexity of the attractor. Lastly, the amount of disorder of the system is described by a Kolmogorov-type entropy estimate. All six aforementioned tests were also implemented on ten levels of detail coefficients resulting from a discrete wavelet transformation of the same signal as used above. Through this analysis it is possible to identify and describe micro (particle level), meso (clustering or turbulence level), and macro (physical or dimensional level) length scales even though some literature considers these scales inseparable [6]. This investigation also used detail wavelet coefficients in conjunction with ANOVA analysis to show which scales have the most impact on the raw signal resulting from local hydrodynamic conditions

Early Identification of Developmental Coordination Disorder: Gender Differences in Performance of the Movement Assessment Battery in Preschool-age Children

Developmental coordination disorder (DCD) is a neurodevelopmental disorder often highlighted by a severe lack of motor coordination that interferes with activities of daily living. The prevalence of DCD in children ranges from 2 to 20% in the United States. Early identification and early intervention can help mitigate potential long term negative effects. The movement assessment battery for children (MABC-2) is a commonly used tool used to identify DCD. PURPOSE: This study examined gender differences in performance on the MABC-2 between preschool-age children. METHODS: 45 preschool-age children (26 girls and 19 boys, Mage = 4.0) were assessed using the MABC-2. The MABC-2 is comprised of 8 items across three subdomains (aiming and catching, manual dexterity, and balance). An independent samples t-test was conducted to observe the differences in each of the 3 sub domains of the MABC between boys and girls and by age. RESULTS: Overall, 39 of children were not at-risk for DCD, and 4 children were at-risk for DCD. The results show a significant difference in the balance domain with girls demonstrating more proficiency (p =0.03) than the boys. There were no significant differences found in manual dexterity (p = .76), aiming and catching (p =0.60), and overall test score (p = 0.18). There were no significant differences based on age across any of the domains. CONCLUSION: Early assessment of young children may be important as potential gender differences already exist by preschool-age. Separate norms may be necessary for boys and girls in this age band as several studies have consistently identified gender differences in the MABC-2. Further exploration of why these differences may exist at such an early age should be explored

The Association between Parent\u27s Perception and Child\u27s Actual Motor Skills in Preschool-age Children

The preschool years is a critical time for the optimal development of children\u27s fine and gross motor skills for future engagement in physical activity. Parents play a critical role in the development of these skills and early identification of potential developmental delays in their children. Early identification of developmental delay is essential for early intervention and rely on accurate child screenings that are often administered by parents. Few studies have compared the accuracy of parent’s perceptions across two different measurements with children\u27s actual motor skills. PURPOSE: This study compared parents\u27 perceptions of their child’s motor skills on two assessments with their actual performance on the MABC-2. METHODS: 45 preschool-age children across the metro DFW area participated in this study (26 girls and 19 boys, Mage = 4.0).  IRB approval was obtained for all participants. Children were assessed using the MABC-2. The MABC-2 is comprised of 8 items across three subdomains (aiming and catching, manual dexterity, and balance). Parents completed two separate surveys on the perception of their child\u27s motor skills (Ages and Stages Questionnaire (ASQ), and the Little Developmental Coordination Disorder questionnaire (LDCDQ). The ASQ ask parents to compare their child\u27s abilities against other children within the same age group across five different domains (communication, gross motor, fine motor, personal-social, and problem solving). The LDCDQ ask parents to rate their child’s gross and fine motor abilities across fifteen different items. Bivariate correlations were used to analyze the relationship between parent responses and children’s scores on the MABC-2. RESULTS: On the LDCDQ, parents rating on fine motor skills was significantly related to total MABC-2 score; (p = .006, R = 0.402), manual dexterity (p= .038, R = 0.310), and aiming and catching (p-value = .005, R = 0.407). On the ASQ, parent\u27s ratings on fine motor skills were significantly related to total MABC-2 scores (p= .048, R = 0.303). Parent’s ratings on their child’s ASQ personal social skills were significantly related to total MABC-2 scores (p= .011, R = 0.385), and aiming and catching (p = .013, R = 0.377). No other correlations were significant amongst the parent assessments and child’s MABC scores. CONCLUSION: While neither assessment appeared to be more related to children\u27s actual scores than the other, in both assessments fines motors skills were more closely related to children\u27s actual performance