scholarly journals Comparison of PM2.5 in Seoul, Korea Estimated from the Various Ground-Based and Satellite AOD

2021 ◽  
Vol 11 (22) ◽  
pp. 10755
Author(s):  
Sang-Min Kim ◽  
Ja-Ho Koo ◽  
Hana Lee ◽  
Jungbin Mok ◽  
Myungje Choi ◽  
...  
Keyword(s):  
Satellite Remote Sensing ◽  
Correlation Coefficients ◽  
Reasonable Accuracy ◽  
High Quality ◽  
Polar Orbit ◽  
Winter Condition ◽  
The Difference ◽  
Mlr Model

Based on multiple linear regression (MLR) models, we estimated the PM2.5 at Seoul using a number of aerosol optical depth (AOD) values obtained from ground-based and satellite remote sensing observations. To construct the MLR model, we consider various parameters related to the ambient meteorology and air quality. In general, all AOD values resulted in the high quality of PM2.5 estimation through the MLR method: mostly correlation coefficients >~0.8. Among various polar-orbit satellite AODs, AOD values from the MODIS measurement contribute to better PM2.5 estimation. We also found that the quality of estimated PM2.5 shows some seasonal variation; the estimated PM2.5 values consistently have the highest correlation with in situ PM2.5 in autumn, but are not well established in winter, probably due to the difficulty of AOD retrieval in the winter condition. MLR modeling using spectral AOD values from the ground-based measurements revealed that the accuracy of PM2.5 estimation does not depend on the selected wavelength. Although all AOD values used in this study resulted in a reasonable accuracy range of PM2.5 estimation, our analyses of the difference in estimated PM2.5 reveal the importance of utilizing the proper AOD for the best quality of PM2.5 estimation.

scholarly journals Enhancement of Satellite Imagesusing Image Sharpening Technique

2019 ◽  
Vol 8 (6S2) ◽  
pp. 351-354
Keyword(s):  
Image Processing ◽  
Color Image ◽  
Histogram Equalization ◽  
Grayscale Image ◽  
Original Image ◽  
High Quality ◽  
Wide Range ◽  
Equalization Technique ◽  
The Difference

In many image processing applications, a wide range of image enhancement techniques are being proposed. Many of these techniques demanda lot of critical and advance steps, but the resultingimage perception is not satisfactory. This paper proposes a novel sharpening method which is being experimented with additional steps. In the first step, the color image is transformed into grayscale image, then edge detection process is applied using Laplacian technique. Then deduct this image from the original image. The resulting image is as expected; After performing the enhancement process,the high quality of the image can be indicated using the Tenengrad criterion. The resulting image manifested the difference in certain areas, the dimension and the depth as well. Histogram equalization technique can also be applied to change the images color.

scholarly journals Estimation of Surface Concentrations of Black Carbon from Long-Term Measurements at Aeronet Sites over Korea

2020 ◽  
Vol 12 (23) ◽  
pp. 3904
Author(s):  
Yongjoo Choi ◽  
Young Sung Ghim ◽  
Ying Zhang ◽  
Seung-Myung Park ◽  
In-ho Song
Keyword(s):  
Black Carbon ◽  
Measurement Data ◽  
Water Soluble ◽  
Mixing Rule ◽  
Range Transport ◽  
Urban Rural ◽  
Fine Mode ◽  
The Difference ◽  
Mlr Model

We estimated fine-mode black carbon (BC) concentrations at the surface using AERONET data from five AERONET sites in Korea, representing urban, rural, and background. We first obtained the columnar BC concentrations by separating the refractive index (RI) for fine-mode aerosols from AERONET data and minimizing the difference between separated RIs and calculated RIs using a mixing rule that can represent a real aerosol mixture (Maxwell Garnett for water-insoluble components and volume average for water-soluble components). Next, we acquired the surface BC concentrations by establishing a multiple linear regression (MLR) between in-situ BC concentrations from co-located or adjacent measurement sites, and columnar BC concentrations, by linearly adding meteorological parameters, month, and land-use type as the independent variables. The columnar BC concentrations estimated from AERONET data using a mixing rule well reproduced site-specific monthly variations of the in-situ measurement data, such as increases due to heating and/or biomass burning and long-range transport associated with prevailing westerlies in the spring and winter, and decreases due to wet scavenging in the summer. The MLR model exhibited a better correlation between measured and predicted BC concentrations than those based on columnar concentrations only, with a correlation coefficient of 0.64. The performance of our MLR model for BC was comparable to that reported in previous studies on the relationship between aerosol optical depth and particulate matter concentration in Korea. This study suggests that the MLR model with properly selected parameters is useful for estimating the surface BC concentration from AERONET data during the daytime, at sites where BC monitoring is not available.

Growth and Characterization of Single Crystal Epitaxial CoGa on MBE Grown III-V Semiconductors

1988 ◽  
Vol 144 ◽  
Author(s):  
K. C. Garrison ◽  
C. J. Palmstrøm ◽  
R. A. Bartynski
Keyword(s):  
Substrate Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Structural Quality ◽  
High Quality ◽  
Auger Analysis ◽  
Post Deposition

ABSTRACTWe have demonstrated growth of high quality single crystal CoGa films on Ga1−xAlxAs. These films were fabricated in-situ by codeposition of Co and Ga on MBE grown Ga1−xAlxAs(100) surfaces. The elemental composition of the films was determined using Rutherford Backscattering (RBS) and in-situ Auger analysis. The structural quality of the films' surfaces was studied using RHEED (during deposition) and LEED (post deposition). RBS channeling was used to determine the bulk crystalline quality of these films.For ∼500 Å CoGa films grown at ∼450°C substrate temperature, channeling data showed good quality epitaxial single crystals [χmin ∼7%] with minimal dechanneling at the interface.

scholarly journals The 2015–2016 carbon cycle as seen from OCO-2 and the global in situ network

2019 ◽  
Vol 19 (15) ◽  
pp. 9797-9831 ◽  
Author(s):  
Sean Crowell ◽  
David Baker ◽  
Andrew Schuh ◽  
Sourish Basu ◽  
Andrew R. Jacobson ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Total Carbon ◽  
Transport Models ◽  
New Information ◽  
Global Coverage ◽  
The Difference ◽  
The Tropics

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques, and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within the ensemble spread, in situ observations, and satellite retrievals constrain a similar global total carbon sink of 3.7±0.5 PgC yr−1, and 1.5±0.6 PgC yr−1 for global land, for the 2015–2016 annual mean. This agreement breaks down in smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.

scholarly journals Comparison and Investigation of Exosomes Derived from Platelet-Rich Plasma Activated by Different Agonists

2021 ◽  
Vol 30 ◽  
pp. 096368972110178
Author(s):  
Shunli Rui ◽  
Yi Yuan ◽  
Chenzhen Du ◽  
Peiyang Song ◽  
Yan Chen ◽  
...  
Keyword(s):  
Calcium Gluconate ◽  
Platelet Rich Plasma ◽  
Saline Group ◽  
Signal Pathway ◽  
Biological Functions ◽  
High Quality ◽  
Bioactive Substances ◽  
The Difference ◽  
Erk Signal Pathway

PRP-Exos are nanoscale cup-shaped vesicles that carry a variety of proteins, mRNAs, microRNAs, and other bioactive substances. PRP-Exos can be formed through several induction pathways, which determine their molecular profiles and facilitate their tailormade participation in intercellular communication. Currently, little is known on how the PRP-Exos activation method influences the quality and quantity of PRP-Exos. The present study aims to observe and analyze the number, profile, and growth factors of PRP-Exos through TEM, Nanoflow, and WB after PRP activation and compare the difference in function of PRP-Exos on HUVECs, with different stimuli (calcium gluconate, thrombin, or both). We found that PRP activated with both thrombin and calcium gluconate harvested the highest concentration of exosomes [(7.16 ± 0.46) × 1010 particles/ml], compared to thrombin group [(4.87 ± 0.15) × 1010 particles/ml], calcium gluconate group [(5.85 ± 0.43) × 1010 particles/ml], or saline group [(7.52 ± 0.19) × 109 particles/ml], respectively ( P < 0.05) via Nanoflow analysis. The WB analysis showed that cytokines (VEGF, PDGFBB, bFGF, TGF-β) are differentially encapsulated in PRP-Exos, depending on the PRP stimulus, in which the mixture-PRP-Exos yielded the highest concentration of cytokines. In the function assay of PRP-Exos on HUVECs, the mixture-PRP-Exos promoted HUVECs proliferation, increased HUVECs migration, promoted the formation of vessel-like by HUVECs via the AKT ERK signal pathway more dramatically, compared with other groups. In summary, our studies showed that PRP activated by the mixture of calcium gluconate and thrombin harvested the best quality of exosomes which had the top biological functions. This study provides a protocol for selecting appropriate PRP activators to obtain high-quality exosomes for future applications.

scholarly journals Assessment of patient satisfaction of certified and non-certified private dental clinics in Athens

2020 ◽  
Vol 6 (1) ◽  
pp. 35
Author(s):  
Evangelia Zampa ◽  
Spyridon Silvestros ◽  
Vasiliki Kapaki ◽  
Kyriakos Souliotis
Keyword(s):  
Practical Interest ◽  
Correlation Coefficients ◽  
Dental Patients ◽  
Education Of Patients ◽  
Dental Clinics ◽  
The Social ◽  
Aggregate Sample ◽  
Dental Practices ◽  
The Difference

Background: In recent years, the issue of quality assurance in health services has emerged in the forefront, with strong research and practical interest. In addition, there is a number of changes to health service users who nowadays have higher expectations of satisfaction, efficiency and quality of health services.Aim: The aim of the present study is to assess the satisfaction of patients and, by extension, the quality of the services provided both in certified and non-certified private dental practices in Athens, to highlight the difference in the services provided and the areas in which it appears.Methods: This is a quantitative study of dental patients’ satisfaction in Athens using an anonymous and self-completed questionnaire. The aggregate sample collected is 317 patients within three months of the questionnaire being shared. In particular, the sample for certified dental places was 176 patients, while the sample of non-certified dental places was 141 patients. For the statistical analysis, the SPSS program for Windows version 25 was used, and the tables were created with Microsoft Excel 2010 based on the SPSS analysis data.Results: The results showed differences between the social level of patients, the permanent residence of the participants as well as differences in the reason for choice and visit to each dental place, while on the questions about the satisfaction of the services the differences were little. The questions with the most shared responses were those in the financial basis. Correlation coefficients did not show any statistically significant relationship between demographic characteristics and satisfaction, with the exception of the level of education of patients in certified dental clinics.Conclusions: Although the results of the research showed little differences in the satisfaction of the patients between certified and non-certified dental clinics, these results are quite limited due to the small number of certified dental clinics in Greece. Further research is needed to produce safer conclusions.

The Public Procurement and the Quality of Services: The Case of Moscow Hospitals

2020 ◽  
pp. 118-131
Author(s):  
Margarita  V. Kravtsova
Keyword(s):  
Public Procurement ◽  
Medical Services ◽  
Key Factors ◽  
High Quality ◽  
Factors Affecting ◽  
The Public ◽  
Goods And Services ◽  
The Difference ◽  
Positive Effect

The work is devoted to the search for answers to the question: “Are there any differences in the public procurement of customers who provide services of different quality?”. The article identifies the stages of the hospital procurement process in the contract system and highlights the main customer strategies used in the auction. The results of an independent quality assessment are examined and comparative hospital characteristics with low and high quality rating are conducted. The hospital needs according to the types of purchases and their annual volumes of contracts are analyzed. The advantages of competitive procedures are determined and the key factors affecting the level of competition with possible risks of unreliable execution of contracts are identified. The empirical study is based on the database which includes 5390 contracts of 2 hospitals in Moscow for years of 2011–2017. Using the methods of econometric analysis, in particular, the method of least squares and the difference in the average, the hypothesis is tested the high competition has a positive effect on the quality of medical services. The constructed regression models show that the customer providing high quality services has low competition and small rebates at the auction. At the same time there are more contract terms, delays in the supply of goods and services as compared with the customer providing low quality services. Thus it was found that the underestimation of competition at the auction indicates the desire of the hospital to guarantee a higher quality of medical services to patients while as aggressive bids of participants lead to the supply of poor purchases. The results of the study may be useful for the competent authorities in the development of legal acts for the participants of the contract system in the field of health procurement.

scholarly journals Compaction Quality Inspection Method of Soil-Rock Filled Embankment Based on Continuous Compaction Control Technology

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhuoling He ◽  
Junyun Zhang
Keyword(s):  
Deformation Modulus ◽  
Control Points ◽  
Inspection Method ◽  
Continuous Compaction Control ◽  
Compaction Control ◽  
Vibratory Compaction ◽  
The Difference ◽  
Main Basis

Affected by the site construction conditions, the measurement passes of the Taihang Expressway K8 + 105 ∼ K8 + 341 (K8 worksite) in the Taihang Expressway did not meet the requirements of data analysis, and the quantity of the control points was insufficient so that the linear correlation between the dynamic deformation modulus () and the vibratory compaction value (VCV) was not strong. Therefore, the target value of VCV cannot be used to diagnose the E v   d compaction quality of soil-rock filler. This paper analyzes the roller measurement VCV value and in situ measurements E v   d value separately. Results reveal the difference between the VCV mean measured in the last two passes and the standard deviation of the measured VCV mean in the last pass are used as the main basis for the actual compaction quality. In addition, the E v   d mean in the last rolling can be used as an auxiliary judgment basis for the quality control of the compaction.

scholarly journals The 2015–2016 Carbon Cycle As Seen from OCO-2 and the Global <i>In Situ</i> Network

2019 ◽  
Author(s):  
Sean Crowell ◽  
David Baker ◽  
Andrew Schuh ◽  
Sourish Basu ◽  
Andrew R. Jacobson ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Total Carbon ◽  
Transport Models ◽  
New Information ◽  
Global Coverage ◽  
The Difference ◽  
The Tropics

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within ensemble spread, in situ observations and satellite retrievals constrain a similar global total carbon sink of 3.7 ± 0.5 PgC, and 1.5 ± 0.6 PgC per year for global land, for the 2015–2016 annual mean. This agreement breaks down on smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.

Analysis of Quality of Services in Higher Education Institutions

2020 ◽  
pp. 349-365
Author(s):  
Ivana Jošanov-Vrgović ◽  
Ana Jovičić Vuković ◽  
Nataša Papić-Blagojević ◽  
Dragana Bolesnikov
Keyword(s):  
Higher Education ◽  
Higher Education Institutions ◽  
Perceived Quality ◽  
Competitive Environment ◽  
Quality Of Services ◽  
High Quality ◽  
Main Factors ◽  
The Difference ◽  
To Receive

An overview of domestic and foreign literature shows that the concept of quality of services at higher education institutions (HEIs) is the focus. Quality of service is one of the main factors of competitive advantage. Perceived quality of services in HEIs can be defined as the difference between what students expect to receive and their perceptions of what they really get. If HEIs get acquainted with students' expectations, they will have the opportunity to adjust their behavior to what is expected of them, and thus to positively influence on the students' perceived quality of services. Globalization has created a more competitive environment and opened market for HEIs. It affected on ensuring high quality in HEIs. The quality of HEIs is of key importance for a society because the students, employers, and society have the benefits of it, and quality education contributes to economic development of the country.

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