The Experts below are selected from a list of 4833 Experts worldwide ranked by ideXlab platform
Ing-jer Huang - One of the best experts on this subject based on the ideXlab platform.
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A reverse-encoding-based on-chip bus tracer for efficient Circular-Buffer utilization
IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2010Co-Authors: Fu Ching Yang, Cheng Lung Chiang, Ing-jer HuangAbstract:Hardware debuggers and logic analyzers must be able to record a continuous trace of data. Since the trace data are tremendous, to save space, these traces are often compressed. The compression algorithm must be simple for hardware implementation; a common method is to store only the difference between the previous value and the current one. Such differential compression has trouble with the Circular Buffer that is needed for recording continuous traces. Previous solutions are complex and waste memory. By a transformation that expresses differential compression in reverse form, we derive a new solution that is simpler than previous methods and does not waste memory. Our algorithm is based on an innovative reverse-encoding scheme by reversing the order of the datum being encoded and the datum being referred. This algorithm has been successfully implemented in a real-time on-chip advanced high-performance bus tracer and has been embedded in a 3-D graphics system-on-a-chip as an application example. The bus tracer costs only 44 K gates and runs at 500 MHz in TSMC 0.13-??m technology. Experiments have shown that our bus tracer achieves 100% Circular-Buffer utilization and captures 4.86 times trace depths as compared with a conventional industrial approach.
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a reverse encoding based on chip ahb bus tracer for efficient Circular Buffer utilization
Asia and South Pacific Design Automation Conference, 2009Co-Authors: Fu Ching Yang, Cheng Lung Chiang, Ing-jer HuangAbstract:The post-T/pre-T trace refers to the trace captured before/after a target point is reached, respectively. Real time compression of the post-T trace in a Circular Buffer is a challenging problem since the initial state of the trace being compressed might be corrupted when wrapping around occurs and thus, makes it difficult to reconstruct the trace from the incomplete information stored in the Circular Buffer. This paper proposes an efficient compression algorithm which is capable of compressing both pre-T and post-T traces. The algorithm is based on an innovative reverse encoding scheme by reversing the order of the datum being encoded and the datum being referred. This algorithm has been successfully implemented in a realtime on-chip AHB bus tracer and has been embedded in a 3D graphics SoC as an application example. The bus tracer costs only 44K gates and runs at 500MHz on 0.13um technology. Experiments have shown that this bus tracer achieves 100% Circular Buffer utilization and captures 1.2x and 4.86x trace depths than state-of-the-art related work and conventional industrial approaches, respectively.
Neil Brummitt - One of the best experts on this subject based on the ideXlab platform.
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subpopulations locations and fragmentation applying iucn red list criteria to herbarium specimen data
Biodiversity and Conservation, 2010Co-Authors: Malin C Rivers, Steven P Bachman, Thomas R Meagher, Eimear Nic Lughadha, Neil BrummittAbstract:Despite the ecological and economic importance of plants, the majority of plant species and their conservation status are still poorly known. Based on the limited knowledge we have of many plant species, especially those in the tropics, the use of GIS techniques can give us estimates of the degree of population subdivision to be used in conservation assessments of extinction risk. This paper evaluates how best to use the IUCN Red List Categories and Criteria to produce effective and consistent estimates of subpopulation structure based on specimen data available in the herbaria around the world. We assessed population structure through GIS-based analysis of the geographic distribution of collections, using herbarium specimen data for 11 species of Delonix sensu lato. We used four methods: grid adjacency, Circular Buffer, Rapoport’s mean propinquity and alpha hull, to quantify population structure according to the terms used in the IUCN Red List: numbers of subpopulations and locations, and degree of fragmentation. Based on our findings, we recommend using the Circular Buffer method, as it is not dependent on collection density and allows points to be added, subtracted and/or moved without altering the Buffer placement. The ideal radius of the Buffer is debatable; however when dispersal characteristics of the species are unknown then a sliding scale, such as the 1/10th maximum inter-point distance, is the preferred choice, as it is species-specific and not sensitive to collection density. Such quantitative measures of population structure provide a rigorous means of applying IUCN criteria to a wide range of plant species that hitherto were inaccessible to IUCN classification.
Rodrigo Siqueira Reis - One of the best experts on this subject based on the ideXlab platform.
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built environment and physical activity domain and activity specific associations among brazilian adolescents
BMC Public Health, 2017Co-Authors: Inacio Crochemore Mohnsam Da Silva, Adriano Akira Ferreira Hino, Adalberto Aparecido Dos Santos Lopes, Ulf Ekelund, Soren Brage, Helen Goncalves, Ana M B Menezes, Rodrigo Siqueira ReisAbstract:Physical activity is likely to be determined as a complex interplay between personal, interpersonal, and environmental factors. Studying the built environment involves expanding the focus from the individual perspective to a public health one. Therefore, the objetive of this study was to examine the association between the built environment and objectively-measured physical activity among youth. Cross-sectional analysis of data from of a Brazilian birth cohort during adolescence. Physical activity was measured using accelerometers (GENEActiv) and self-report (International Physical Activity Questionnaire, long version). Participants’ home addresses were geocoded and built environment characteristics such as streets’ pattern and quality, and public open spaces attributes for physical activity practice were evaluated in a 500-m Circular Buffer surrounding their homes. A total of 3379 participants were included. Street lighting (β = 2.2; 95%CI: 0.5; 3.9) was positively associated with objectively-measured moderate-vigorous physical activity (MVPA) and proportion of paved streets and Buffer’s average family income were associated with lower MVPA. Living near the beach increased the odds of leisure-time MVPA practice by 3.3 (95%CI: 1.37; 8.02) times. There was a built environment-by-socioeconomic status (SES) interaction for the associations with commuting physical activity; street lighting [Odds ratio (OR) = 1.22; 95%CI: 1.01; 1.47] and presence of cycle lanes (OR = 1.77; 95%CI: 1.05; 2.96) were positively associated with commuting physical activity only among the intermediate SES tertile. Beachfront, street lighting, paved streets and cycle lanes were associated with physical activity patterns. This suggests that infrastructure interventions may influence physical activity levels of Brazilian adolescents.
Fu Ching Yang - One of the best experts on this subject based on the ideXlab platform.
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A reverse-encoding-based on-chip bus tracer for efficient Circular-Buffer utilization
IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2010Co-Authors: Fu Ching Yang, Cheng Lung Chiang, Ing-jer HuangAbstract:Hardware debuggers and logic analyzers must be able to record a continuous trace of data. Since the trace data are tremendous, to save space, these traces are often compressed. The compression algorithm must be simple for hardware implementation; a common method is to store only the difference between the previous value and the current one. Such differential compression has trouble with the Circular Buffer that is needed for recording continuous traces. Previous solutions are complex and waste memory. By a transformation that expresses differential compression in reverse form, we derive a new solution that is simpler than previous methods and does not waste memory. Our algorithm is based on an innovative reverse-encoding scheme by reversing the order of the datum being encoded and the datum being referred. This algorithm has been successfully implemented in a real-time on-chip advanced high-performance bus tracer and has been embedded in a 3-D graphics system-on-a-chip as an application example. The bus tracer costs only 44 K gates and runs at 500 MHz in TSMC 0.13-??m technology. Experiments have shown that our bus tracer achieves 100% Circular-Buffer utilization and captures 4.86 times trace depths as compared with a conventional industrial approach.
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a reverse encoding based on chip ahb bus tracer for efficient Circular Buffer utilization
Asia and South Pacific Design Automation Conference, 2009Co-Authors: Fu Ching Yang, Cheng Lung Chiang, Ing-jer HuangAbstract:The post-T/pre-T trace refers to the trace captured before/after a target point is reached, respectively. Real time compression of the post-T trace in a Circular Buffer is a challenging problem since the initial state of the trace being compressed might be corrupted when wrapping around occurs and thus, makes it difficult to reconstruct the trace from the incomplete information stored in the Circular Buffer. This paper proposes an efficient compression algorithm which is capable of compressing both pre-T and post-T traces. The algorithm is based on an innovative reverse encoding scheme by reversing the order of the datum being encoded and the datum being referred. This algorithm has been successfully implemented in a realtime on-chip AHB bus tracer and has been embedded in a 3D graphics SoC as an application example. The bus tracer costs only 44K gates and runs at 500MHz on 0.13um technology. Experiments have shown that this bus tracer achieves 100% Circular Buffer utilization and captures 1.2x and 4.86x trace depths than state-of-the-art related work and conventional industrial approaches, respectively.
Shihchun Candice Lung - One of the best experts on this subject based on the ideXlab platform.
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how is environmental greenness related to students academic performance in english and mathematics
Landscape and Urban Planning, 2019Co-Authors: Wing Tuen Veronica Leung, Wenchi Pan, Tuen Yee Tiffany Tam, Shihchun Candice Lung, John D SpenglerAbstract:Abstract Background Previous studies point out a positive association between academic performance and school surrounding greenness, but the population included in these studies only recruited single-grade students. Objectives To design a more all-rounded investigation of the association between school surrounding greenness and students’ academic performance in general in Massachusetts, USA. Methods We included a total of 27,493 3rd–10th grade students from public schools over 9 years (2006–2014) in the study. Academic performance (i.e. English and Mathematics achievement level) were primarily based on Composite Performance Index (CPI) as well as the percentage of students who scored “Proficient and Higher” (AP%) in the examination. Normalized Difference Vegetation Index (NDVI) and green land use area (within 250–2000 m Circular Buffer) were used to server the index of school surrounding greenness). We applied generalized linear mixed models (GLMMs) to investigate the relationship between surrounding greenness and academic performance with adjustment on socio-economic and demographic factors. Results We found a significant positive association (p Conclusions A higher surrounding greenness contributes a better academic performance in students of all grades. This finding could serve as a reference for designing green landscape especially near school areas.
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land use regression with long term satellite based greenness index and culture specific sources to model pm2 5 spatial temporal variability
Environmental Pollution, 2017Co-Authors: Yucheng Chen, Wenchi Pan, Shihchun Candice Lung, Yu Ting Zeng, Mu Jean Chen, Yue Leon GuoAbstract:Abstract This study utilized a long-term satellite-based vegetation index, and considered culture-specific emission sources (temples and Chinese restaurants) with Land-use Regression (LUR) modelling to estimate the spatial-temporal variability of PM 2.5 using data from Taipei metropolis, which exhibits typical Asian city characteristics. Annual average PM 2.5 concentrations from 2006 to 2012 of 17 air quality monitoring stations established by Environmental Protection Administration of Taiwan were used for model development. PM 2.5 measurements from 2013 were used for external data verification. Monthly Normalized Difference Vegetation Index (NDVI) images coupled with Buffer analysis were used to assess the spatial-temporal variations of greenness surrounding the monitoring sites. The distribution of temples and Chinese restaurants were included to represent the emission contributions from incense and joss money burning, and gas cooking, respectively. Spearman correlation coefficient and stepwise regression were used for LUR model development, and 10-fold cross-validation and external data verification were applied to verify the model reliability. The results showed a strongly negative correlation (r: −0.71 to −0.77) between NDVI and PM 2.5 while temples (r: 0.52 to 0.66) and Chinese restaurants (r: 0.31 to 0.44) were positively correlated to PM 2.5 concentrations. With the adjusted model R 2 of 0.89, a cross-validated adj-R 2 of 0.90, and external validated R 2 of 0.83, the high explanatory power of the resultant model was confirmed. Moreover, the averaged NDVI within a 1750 m Circular Buffer ( p p p = 0.06) were selected as important predictors during the stepwise selection procedures. According to the partial R 2 , NDVI explained 66% of PM 2.5 variation and was the dominant variable in the developed model. We suggest future studies consider these three factors when establishing LUR models for estimating PM 2.5 in other Asian cities.
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linking student performance in massachusetts elementary schools with the greenness of school surroundings using remote sensing
PLOS ONE, 2014Co-Authors: Eileen Mcneely, Wenchi Pan, Shihchun Candice Lung, Jose Guillermo Cedenolaurent, Gary Adamkiewicz, Francesca Dominici, John D SpenglerAbstract:Various studies have reported the physical and mental health benefits from exposure to “green” neighborhoods, such as proximity to neighborhoods with trees and vegetation. However, no studies have explicitly assessed the association between exposure to “green” surroundings and cognitive function in terms of student academic performance. This study investigated the association between the “greenness” of the area surrounding a Massachusetts public elementary school and the academic achievement of the school’s student body based on standardized tests with an ecological setting. Researchers used the composite school-based performance scores generated by the Massachusetts Comprehensive Assessment System (MCAS) to measure the percentage of 3rd-grade students (the first year of standardized testing for 8–9 years-old children in public school), who scored “Above Proficient” (AP) in English and Mathematics tests (Note: Individual student scores are not publically available). The MCAS results are comparable year to year thanks to an equating process. Researchers included test results from 2006 through 2012 in 905 public schools and adjusted for differences between schools in the final analysis according to race, gender, English as a second language (proxy for ethnicity and language facility), parent income, student-teacher ratio, and school attendance. Surrounding greenness of each school was measured using satellite images converted into the Normalized Difference Vegetation Index (NDVI) in March, July and October of each year according to a 250-meter, 500-meter, 1,000-meter, and 2000-meter Circular Buffer around each school. Spatial Generalized Linear Mixed Models (GLMMs) estimated the impacts of surrounding greenness on school-based performance. Overall the study results supported a relationship between the “greenness” of the school area and the school-wide academic performance. Interestingly, the results showed a consistently positive significant association between the greenness of the school in the Spring (when most Massachusetts students take the MCAS tests) and school-wide performance on both English and Math tests, even after adjustment for socio-economic factors and urban residency.