74 research outputs found

    Evaluation of an Extended PICS (EPICS) for Calibration and Stability Monitoring of Optical Satellite Sensors

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    Pseudo Invariant Calibration Sites (PICS) have been increasingly used as an independent data source for on-orbit radiometric calibration and stability monitoring of optical satellite sensors. Generally, this would be a small region of land that is extremely stable in time and space, predominantly found in North Africa. Use of these small regions, referred to as traditional PICS, can be limited by: i) the spatial extent of an individual Region of Interest (ROI) and/or site; ii) and the frequency of how often the site can be acquired, based on orbital patterns and cloud cover at the site, both impacting the time required to construct a richly populated temporal dataset. This paper uses a new class of continental scaled PICS clusters (also known as Extended PICS or EPICS), to demonstrate their capability in increasing temporal frequency of the calibration time series which ultimately allows calibration and stability assessment at a much finer scale compared to the traditional PICSbased method while also reducing any single location’s potential impact to the overall assessment. The use of EPICS as a calibration site was evaluated using data from Landsat- 8 Operational Land Imager (OLI), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and Sentinel-2A&B Multispectral Instrument (MSI) images at their full spatial resolutions. Initial analysis suggests that EPICS, at its full potential and with nominal cloud consideration, can significantly decrease the temporal revisit interval of moderate resolution sensors to as much as of 0.33 day (3 collects/day). A traditional PICS is expected to have a temporal uncertainty (defined as the ratio of temporal standard deviation and temporal mean) of 2-5% for TOA reflectance. Over the same time period EPICS produced a temporal uncertainty of 3%. But the advantage to be leveraged is the ability to detect sensor change quicker due to the denser dataset and reduce the impact of any potential ‘local’ changes. Moreover, this approach can be extended to any on-orbit sensor. An initial attempt to quantify the minimum detectable change (a threshold slope value which must be exceeded by the reflectance trend to be considered statistically significant) suggests that the use of EPICS can decrease the time period up to approximately half of that found using traditional PICS-based approach

    Comparative Study of Magnetization of Co Thin Films Deposited on Glass, GaAs (001) and Si (001) Substrates

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    The effect of surface induced anisotropy and interfacial anisotropy on the magnetic properties of Co thin films have been presented. The surface roughness of 100 nm Co film on both the glass and Si (001) substrate is found to be ~ 50 Oe. But the surface roughness of the same thick Co film on GaAs (001) substrate is enhanced to ~ 80 Oe. The enhancement of coercivity of Co thin film on GaAs (001) substrate is due to the special interaction between transition metal Co and GaAs (001). The anisotropy field due to the cobalt silicide interface is responsible for large saturation field required to saturate the Co/Si sample. The squareness of Co thin film on both the glass and GaAs (001) is ~ 1. On the other hand, it is reduced to 0.45 for Co/Si system. Both the surface induced and interfacial anisotropy fields influence the shape of the hysteresis loop

    Sustainable Development of Apparel Industry in Bangladesh: A Critical Review

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    Bangladesh’s apparel industry has become the country’s economic foundation. The textile and apparel employees especially over four million people. In this major industrial sector, it is critical to encourage sustainability. When the apparel market and corporations focus on environmentally friendly products, Bangladesh’s textile and apparel sectors remain far behind, putting the country at risk of losing market share. It is right of passage to implement techniques and a long-term strategy to sustainability. Bangladeshi apparel industries are currently facing significant issues in terms of labor conditions. In garment manufacturers, fires are a common occurrence. Thousands of workers have perished because of these dangers. Due to Bangladesh’s fire and safety difficulties, several foreign purchasers have already opted not to do business with the country again. Furthermore, workers receive the world’s lowest pay, which leaves them dissatisfied and frequently results in conflicts and violence during protests poor wages. This study is conveyed based on theoretical, analytical, and statistical aspects. The goal of this study is to represent the overall picture of sustainability in the apparel industry in Bangladesh. This study illustrates on using a life cycle approach to assessing manufactured products for environmental indicators to attain sustainability, fast fashion, government policy of sustainability, new method and material of garments and compare with the lifestyle of Europe against Bangladesh. This paper investigated Bangladesh’s garment industry’s working environment, fire, and safety hazards, and made suggestions for important environmental and sustainability activities. This study is helpful to all the people because sustainability is the main concern in a day

    Fractal Patterns in the Parameter Space of Bi-stable Duffing Oscillator

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    We study the dissipative bi-stable Duffing oscillator with equal energy wells and observe fractal patterns in the parameter space of driving frequency, forcing amplitude, and damping ratio. Our numerical investigation reveals the Hausdorff fractal dimension of the boundaries that separate the oscillator's intra-well and inter-well behaviors. Furthermore, we categorize the inter-well behaviors as three steady-state types: switching, reverting, and vacillating. While fractal patterns in the phase space are well-known and heavily studied, our results point to a new research direction about fractal patterns in the parameter space. Another implication of this study is that the vibration of a continuous bi-stable system modeled using a single-mode approximation also manifests fractal patterns in the parameter space. In addition, our findings can guide the design of next-generation bi-stable and multi-stable mechanical metamaterials

    Production of organic grass carp (Ctenopharyngodon idella) and GIFT tilapia (Oreochromis niloticus) using napier grass, Pennisetum purpureum

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    This study was conducted to examine the growth and production of grass carp and tilapia cultured organically using napier grass in Bangabanbhu Sheikh Mujibur Rahman Agricultural University, Bangladesh from March-June, 2013. Three stocking ratios were tested: grass carp at 0.6 fish/m2 with GIFT tilapia at 0.3 fish/m2 (T1), grass carp at 0.6 fish/m2 with GIFT tilapia at 0.6 fish/m2 (T2), grass carp at 0.6 fish/m2 with GIFT tilapia at 0.9 fish/m2 (T3) and grass carp only at 0.6 fish/m2 as control (T4). Chopped fresh napier grass leaf was the sole nutrient input and provided twice daily. The water quality parameters were within suitable ranges for fish culture. Grass carp attained a daily growth increment ranging from 2.80-3.73 g/day and GIFT tilapia from 1.30-1.86 g/day. The combined yields was significantly higher (P<0.05) in stocking ratio of 1:1 (2.72 t/ha/90 days) compared to other stocking ratios. The result indicates on the basis of benefit-cost-ratio that the farmer’s income will be around double or more in the combined production of organic grass carp and tilapia with stocking ratio of 1:1 than the other stocking ratios. The density of grass carp should be further studied

    The Impact of User Participation on the Success of Enterprise Resource Planning (ERP) Adoption in Bangladesh

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    The successful adoption of Enterprise Resource Planning (ERP) systems is crucial for organizations to enhance operational efficiency and gain a competitive edge. User participation has been recognized as a key factor in determining the success of ERP implementation. This study aims to investigate the impact of user participation on ERP adoption success in the context of Bangladesh. The specific objectives include assessing the relationship between user participation and work performance, understanding/proficiency, user-friendliness, and training/support. Additionally, the influence of organizational factors, such as organizational value, guidelines/procedures, and resource/support availability, on user participation is examined. The study also explores the impact of user participation on compatibility with existing organizational processes and alignment with strategic goals. The findings reveal that user participation significantly influences work performance, understanding/proficiency, user-friendliness, and training/support. Organizational factors and strategic alignment play important roles in facilitating user participation. The results emphasize the need to foster user participation, provide adequate training and support, promote organizational values, and align strategic goals for successful ERP adoption in Bangladesh. These insights contribute to a better understanding of the factors that drive ERP implementation success and provide guidance for organizations in Bangladesh and similar contexts

    Organoleptic and grain quality traits of aromatic rice varieties as influenced by supplementation of Zn and 2-acetyl-1-pyrroline

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    Aromatic rice fetches premium prices in world markets due to its pleasant smell and enchanting flavor. In Bangladesh, the quality of aromatic rice is much inferior than those of other rice growing countries because of lack of improved variety and judicious agronomic management. Selection of appropriate variety and supplementation zinc (Zn) and 2-acetyl-1-pyrroline (2-AP) can improve the aroma. The present study exhibited the effects of 2-AP and Zn supplementation on yield and quality of aromatic rice. Two well-known aromatic cultivars, BRRI dhan80 and BRRI dhan34, were cultured separately in pot supplemented with 2-AP and Zn. The results showed that supplementation of 2-AP and /or Zn along with conventional practices had significant effects on organoleptic and some quality parameters studied in this study. The concentration of 2AP and Zn in rice grain increased with increasing their application rate. Additionally, grain 2-AP concentrations were significantly and positively correlated with organoleptic characters. Interactions of both these elements with the complex process of 2-AP formation remain to be explored

    Determination of Dichlorodiphenyltrichloroethane Residues Levels in Commercial Marine Dry Fish from Different Regions of Bangladesh

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    Dichlorodiphenyltrichloroethane (DDT) residual levels are available several commercially dry fishes. So, these fishes were detected and determinate the contamination status of dichlorodiphenyltrichloroethane (DDT). The most popular dry fish-Ribbon fish (Lepturacanthus savala), Chinese pomfret (Pampus chinensis), Bombay duck (Harpodon nehereus) and Shrimp sp. (crustaceans) were selected for this study and these dry fishes were collected from nine different markets (three from each of Khulna, Chittagong and Cox's bazar district) of Bangladesh during December-March in 2013. A total number of 36 samples were selected for analyzing in the laboratory by using gas chromatography-mass spectrometry electron captured (GC-ECD) detector. The ranges of DDT in all samples were 2.81 to 877.82ppb. The ranges of DDT in the samples of Bombay duck, Chinese pomfret, Ribbon fish and Shrimp were 13.7-874.35ppb, 2.81-877.82ppb, 3.73-253.68ppb and 4.27-585.97ppb respectively. The mean concentrations of DDT were found highest amount from retailer markets while compared to that from the producer’s markets. Results indicated that the concentration of DDT in dry fish from Bangladesh are higher and may cause chronic disease and potential long-term risk for human health

    Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

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    Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress
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