Actual Reflection Research Articles

The geometry evolution of Early Paleozoic carbonate platform in the southwestern Tarim Basin, China: evidence from sequence stratigraphic analysis and seismic forward modeling

Deciphering the evolution of spatial geometry of carbonate platforms in deeply buried successions is still a challenge due to the low resolution of seismic data and the constraints of drilling wells. In this study, by combining a seismic forward model, we systematically delineated the external morphology and internal architecture of seismic reflection and established a depositional model of a carbonate platform. The Lower Paleozoic strata display the high-amplitude reflection in the Lower-Middle Cambrian interval and the low-amplitude reflection in the Upper Cambrian-Middle Ordovician interval. The high-amplitude reflection interval thins or wedges out towards the center of the present Southwest Depression section, and thickens to the north and south. Inside of the high-amplitude interval, the seismic reflection terminated at the top reflector. Seismic forward modeling was performed to examine the validity of possible hypothetical models in the studied area. The modeling results show that the simulated stratigraphic patterns are comparable to a ramp or depression geometry which is well fit to the characteristics of actual seismic reflections. Such a ramp or depression geometry is built upon the changes in sea level and climate during the Cambrian period. This study emphasizes the potential of the integration of sequence stratigraphic analyses and seismic forward modeling as a seismic workflow for retrieving the stratigraphic architecture and platform geometry.

2022 개정 전문 교과 교육과정의 디지털 역량 분석 연구: 보건·복지 교과(군)을 중심으로

Objectives The purposes of this study were to analyze the current status of digital competencies reflected in the general major (17 subjects) curriculum among the 2022 revised health & welfare specialized subjects. Methods In order to achieve the research objectives, the degree of reflection related to digital competency reflected in the health and welfare subject (group) curriculum items (1. personality and goals, 2. content system and achievement standards, 3. teaching and learning, 4 evaluation) was analyzed using the curriculum mapping (CCM) method based on the DigComp 2.2 Framwork announced by the EU-JRC (2022). And the actual reflection cases were analyzed using a qualitative method. Results Among the 2022 revised health and welfare specialized courses, “2. Communication and Collaboration” was the highest at 26.7%, followed by “1. Information and data literacy” (22.0%), “3. Digital content creation” (18.7%), and “5. Problem solving” (18.3%). And “4. Safety” (14.4%) was the lowest, so it is judged that it is necessary to supplement related contents through teaching and learning activities. Conclusions In order for prospective professionals to adapt to the digitalized work environment in the health and welfare sector and implement the digital capabilities necessary to perform related jobs, it is necessary to develop training programs that can improve teachers' digital capabilities and research related to the establishment of teaching and learning environments.

Global 30 m seamless data cube (2000–2022) of land surface reflectance generated from Landsat 5, 7, 8, and 9 and MODIS Terra constellations

Abstract. The Landsat series constitutes an unparalleled repository of multi-decadal Earth observations, serving as a cornerstone in global environmental monitoring. However, the inconsistent coverage of Landsat data due to its long revisit intervals and frequent cloud cover poses significant challenges to land monitoring over large geographical extents. In this study, we developed a full-chain processing framework for the multi-sensor data fusion of Landsat 5, 7, 8, and 9 and MODIS Terra surface reflectance products. Based on this framework a global 30 m resolution daily seamless data cube (SDC) of land surface reflectance was generated, spanning from 2000 to 2022. A thorough evaluation of the SDC was undertaken using a leave-one-out approach and a cross-comparison with NASA's Harmonized Landsat and Sentinel-2 (HLS) products. The leave-one-out validation at 425 global test sites assessed the agreement between the SDC with actual Landsat surface reflectance values (not used as input), revealing an overall mean absolute error (MAE) of 0.014 (the valid range of surface reflectance values is 0–1). The cross-comparison with HLS products at 22 Military Grid Reference System (MGRS) tiles revealed an overall mean absolute deviation (MAD) of 0.017 with L30 (Landsat 8-based 30 m HLS product) and a MAD of 0.021 with S30 (Sentinel-2-based 30 m HLS product). Moreover, experimental results underscore the advantages of employing the SDC for global land cover classification, achieving a sizable improvement in overall accuracy (2.4 %–11.3 %) over that obtained using Landsat composite and interpolated datasets. A web-based interface has been developed for researchers to freely access the SDC dataset, which is available at https://doi.org/10.12436/SDC30.26.20240506 (Chen et al., 2024).

The VNF Cybersecurity Dataset for Research (VNFCYBERDATA)

Virtualisation has received widespread adoption and deployment across a wide range of enterprises and industries throughout the years. Network Function Virtualisation (NFV) is a technical concept that presents a method for dynamically delivering virtualised network functions as virtualised or software components. Virtualised Network Function (VNF) has distinct advantages, but it also faces serious security challenges. Cyberattacks such as Denial of Service (DoS), malware/rootkit injection, port scanning, and so on can target VNF appliances just like any other network infrastructure. To create exceptional training exercises for machine or deep learning (ML/DL) models to combat cyberattacks in VNF, a suitable dataset (VNFCYBERDATA) exhibiting an actual reflection, or one that is reasonably close to an actual reflection, of the problem that the ML/DL model could address is required. This article describes a real VNF dataset that contains over seven million data points and twenty-five cyberattacks generated from five VNF appliances. To facilitate a realistic examination of VNF traffic, the dataset includes both benign and malicious traffic.

A single reflective surface reveals contextual cue-weighting in spatial hearing

Prominent among the factors supporting accurate sound localizatoin in reverberant scenes is the dominance of sound onsets, which carry binaural cues matching the direct sound rather than its echoes. Aspects of onset dominance can be demonstrated synthetically via localization of paired sounds separated by a brief delay (the “precedence effect”)–a rather extreme simplification of reverberation but a useful one for dissecting the roles of single reflections. In 1985, Brad Rakerd and Bill Hartmann published a precedence-like study [JASA 78(2), 524–533] using actual acoustic reflections induced by a single reflective surface positioned within an otherwise-anechoic space. Figure 3 of that paper shows that the effects on localization depend in a complex way on the direction and proximity of the sound source and its reflections. The impacts on binaural acoustic cues are similarly complex. Localization could be predicted by combinations of these cues only if each cue was weighted by its plausibility (i.e., likelihood given the sensory context). With this 1985 study, Rakerd and Hartmann, thus, revealed a second critical factor for accurate spatial hearing in reverberation: the context-dependent weighting of multiple imperfect sensory cues.

Hard X-ray HfO2/Al2O3 multilayers fabricated by atomic layer deposition

Multilayer is a widely used X-ray optics that can be designed and optimized for specific X-ray application. Atomic layer deposition (ALD) has unique advantage in coating homogeneous ultra-thin film on both flat and curved substrates, which shows great potential in the fabrication of X-ray multilayer with small period. In this paper, hard X-ray HfO2/Al2O3 multilayers on Si substrate prepared by ALD were investigated. The X-ray (0.154 nm) reflectivity of HfO2/Al2O3 multilayer with 3.44 nm period, 60 bilayers is 24 %. Atomic force microscope results show that surface roughness of HfO2/Al2O3 multilayer with total thickness more than 200 nm is slightly larger than that of the substrate. High resolution transmission electron microscope images reveal that amorphous HfO2/Al2O3 material pair forms multilayer with sharp interfaces even for 1.69 nm period. Further study indicates that lowering substrate roughness can reduce the deviation between actual and theoretical X-ray reflectivity. These results demonstrate that for multilayer-based hard X-ray optics, ALD-grown HfO2/Al2O3 is a promising candidate.

Virus neutralization assays for human respiratory syncytial virus using airway organoids

Neutralizing antibodies are considered a correlate of protection against severe human respiratory syncytial virus (HRSV) disease. Currently, HRSV neutralization assays are performed on immortalized cell lines like Vero or A549 cells. It is known that assays on these cell lines exclusively detect neutralizing antibodies (nAbs) directed to the fusion (F) protein. For the detection of nAbs directed to the glycoprotein (G), ciliated epithelial cells expressing the cellular receptor CX3CR1 are required, but generation of primary cell cultures is expensive and labor-intensive. Here, we developed a high-throughput neutralization assay based on the interaction between clinically relevant HRSV grown on primary cells with ciliated epithelial cells, and validated this assay using a panel of infant sera. To develop the high-throughput neutralization assay, we established a culture of differentiated apical-out airway organoids (Ap-O AO). CX3CR1 expression was confirmed, and both F- and G-specific monoclonal antibodies neutralized HRSV in the Ap-O AO. In a side-by-side neutralization assay on Vero cells and Ap-O AO, neutralizing antibody levels in sera from 125 infants correlated well, although titers on Ap-O AO were consistently lower. We speculate that these lower titers might be an actual reflection of the neutralizing antibody capacity in vivo. The organoid-based neutralization assay described here holds promise for further characterization of correlates of protection against HRSV disease.

Study of Optical Performance and Structure of Yb/Al (1.5 wt.% Si) and Yb/Al (Pure) Multilayers Designed for the 73.6 nm Range

Yb/Al multilayer films exhibit excellent theoretical reflectivity in the 54–90 nm wavelength range. This study attempted to incorporate 1.5% wt.% of Si impurities into Al to suppress the crystallization of Al, reduce interfacial roughness, and enhance the actual reflectivity of the prepared Yb/Al multilayer films. Internal microstructure changes in the film layers before and after Si impurity doping were investigated using GIXRR, AFM, and XRD techniques. The reflectivity of two types of multilayer films, Yb/Al (1.5 wt.% Si) and Yb/Al (pure), was tested to evaluate the effect of Si impurity on film performance. The reflectivity of Yb/Al (1.5 wt.% Si) multilayers compared to Yb/Al (pure) multilayers increased by approximately 4%.

Railway Signal Electronic Control System Based on BP Neural Network

Railway signal system is the core system of railway command train operation. After the installation of the system equipment is completed, a comprehensive test shall be carried out through joint debugging and joint testing, and the applicability of the system to the design requirements shall be generally evaluated according to the test results. This paper focuses on the research of railway signal electronic control system. Based on BP neural network, fault information can be quickly and accurately identified in a relatively short time, and accurate electronic signal control can be realized in a complex system environment. The final result of the study shows that the difference in delay error of railway signal transmission under BP neural network technology is small, there are some subtle differences in 5 different modes, but the impact is small, in mode 1, the target time value is 0.236s, The actual reflection time is 0.322s, it can be seen that the error is controlled within 0.2s, which is feasible. Through the analysis of delay error of railway signal electronic control system, BP neural network has certain advantages in railway signal transmission.

New measurements of the hemispherical albedo of cometary analogues: Influence on the amplitude of the change of cometary brightness during its outburst

The paper presents new experimental results of measurements of the hemispherical albedo of a potential comet analogue and an analysis of its influence on the change in the cometary brightness. Measurements of the spectral properties of the tested analogues were performed using a Cary 5000 spectrometer in the wavelength range from 200 to 2500 nm. Two samples were used as a dust analogue: a mixture of sand and ash (sample A) and a mixture of sand and charcoal (sample B), respectively. The obtained hemispherical albedo values for the tested samples ranged from 1.20% to 32.25%. In particular, for sample B, the obtained hemispherical albedo values are comparable to the actual reflectance for comet 67P. Based on the obtained spectral properties of the tested samples, a thermodynamic model of cometary activity was developed and used, among others, to calculate the power absorbed by the tested analogue and the sublimation flux occurring through the porous structure of the fine-grained dust present on the cometary surface. The obtained results were used to calculate the change in the cometary brightness during its outburst, the upper limit of which was equal to 5.36 magnitude.

Characterizing sub-glacial hydrology using radar simulations

Abstract. The structure and distribution of sub-glacial water directly influences Antarctic ice mass loss by reducing or enhancing basal shear stress and accelerating grounding line retreat. A common technique for detecting sub-glacial water involves analyzing the spatial variation in reflectivity from an airborne radar echo sounding (RES) survey. Basic RES analysis exploits the high dielectric contrast between water and most other substrate materials, where a reflectivity increase ≥ 15 dB is frequently correlated with the presence of sub-glacial water. There are surprisingly few additional tools to further characterize the size, shape, or extent of hydrological systems beneath large ice masses. We adapted an existing radar backscattering simulator to model RES reflections from sub-glacial water structures using the University of Texas Institute for Geophysics (UTIG) Multifrequency Airborne Radar Sounder with Full-phase Assessment (MARFA) instrument. Our series of hypothetical simulation cases modeled water structures from 5 to 50 m wide, surrounded by bed materials of varying roughness. We compared the relative reflectivity from rounded Röthlisberger channels and specular flat canals, showing both types of channels exhibit a positive correlation between size and reflectivity. Large (> 20 m), flat canals can increase reflectivity by more than 20 dB, while equivalent Röthlisberger channels show only modest reflectivity gains of 8–13 dB. Changes in substrate roughness may also alter observed reflectivity by 3–6 dB. All of these results indicate that a sophisticated approach to RES interpretation can be useful in constraining the size and shape of sub-glacial water features. However, a highly nuanced treatment of the geometric context is necessary. Finally, we compared simulated outputs to actual reflectivity from a single RES flight line collected over Thwaites Glacier in 2022. The flight line crosses a previously proposed Röthlisberger channel route, with an obvious bright bed reflection in the radargram. Through multiple simulations comparing various water system geometries, such as canals and sub-glacial lakes, we demonstrated the important role that topography and water geometry can play in observed RES reflectivity. From the scenarios that we tested, we concluded the bright reflector from our RES flight line cannot be a Röthlisberger channel but could be consistent with a series of flat canals or a sub-glacial lake. However, we note our simulations were not exhaustive of all possible sub-glacial water configurations. The approach outlined here has broad applicability for studying the basal environment of large glaciers. We expect to apply this technique when constraining the geometry and extent of many sub-glacial hydrologic structures in the future. Further research may also include comprehensive investigations of the impact of sub-glacial roughness, substrate heterogeneity, and computational efficiencies enabling more complex and complete simulations.

Validation of a Model Estimating the Budget Impact of Video Capsule Endoscopy for Surveillance of Crohn’s Disease in an Italian Center

Background: Crohn’s disease is a chronic ailment affecting the gastrointestinal tract. Mucosal healing, a marker of reduced disease activity, is currently assessed in the colonic sections using ileocolonoscopy and magnetic resonance enteroscopy. Video capsule endoscopy (VCE) offers visualization of the entire GI mucosae. Objective: To validate a Crohn’s disease model estimating the budget impact of VCE compared with the standard of care (SOC) in Italy. Methods: A patient-level, discrete-event simulation was developed to estimate the budget impact of VCE compared with SOC for Crohn’s disease surveillance over 5 years in the Italian setting. Input data were sourced from a physician-initiated study from Sant’Orsola-Malpighi Hospital in Bologna, Italy, and the literature. The care pathway followed hospital clinical practice. Comparators were the current SOC (ileocolonoscopy, with or without magnetic resonance enteroscopy) and VCE. Sensitivity analysis was performed using 500-patient bootstraps. A comparative analysis regarding clinical outcomes (biologics use, surgical interventions, symptom remission) was performed to explore the validity of the model compared with real-world data. Cumulative event incidences were compared annually and semi-annually. Bayesian statistical analysis further validated the model. Results: Implementing VCE yielded an estimated €67 savings per patient per year, with savings in over 55% of patients, compared with SOC. While annual costs are higher up to the second year, VCE becomes cost saving from the third year onward. The real-world validation analysis proved a good agreement between the model and real-world patient records. The highest agreement was found for biologics, where Bayesian analysis estimated an 80.4% probability (95% CI: 72.2%-87.5%) that a decision maker would accept the result as an actual reflection of real-world data. Even where trend data diverged (eg, for surgery [43.1% likelihood of acceptance, 95% CI: 33.7%-52.8%]), the cumulative surgery count over 5 years was within the margin of error of the real-world data. Conclusions: Implementing VCE in the surveillance of patients with Crohn’s disease and small bowel involvement may be cost saving in Italy. The congruence between model predictions and real-world patient records supports using this discrete-event simulation to inform healthcare decisions.

Validation of a Model Estimating the Budget Impact of Video Capsule Endoscopy for Surveillance of Crohn's Disease in an Italian Center.

Background: Crohn's disease is a chronic ailment affecting the gastrointestinal tract. Mucosal healing, a marker of reduced disease activity, is currently assessed in the colonic sections using ileocolonoscopy and magnetic resonance enteroscopy. Video capsule endoscopy (VCE) offers visualization of the entire GI mucosae. Objective: To validate a Crohn's disease model estimating the budget impact of VCE compared with the standard of care (SOC) in Italy. Methods: A patient-level, discrete-event simulation was developed to estimate the budget impact of VCE compared with SOC for Crohn's disease surveillance over 5 years in the Italian setting. Input data were sourced from a physician-initiated study from Sant'Orsola-Malpighi Hospital in Bologna, Italy, and the literature. The care pathway followed hospital clinical practice. Comparators were the current SOC (ileocolonoscopy, with or without magnetic resonance enteroscopy) and VCE. Sensitivity analysis was performed using 500-patient bootstraps. A comparative analysis regarding clinical outcomes (biologics use, surgical interventions, symptom remission) was performed to explore the validity of the model compared with real-world data. Cumulative event incidences were compared annually and semi-annually. Bayesian statistical analysis further validated the model. Results: Implementing VCE yielded an estimated €67 savings per patient per year, with savings in over 55% of patients, compared with SOC. While annual costs are higher up to the second year, VCE becomes cost saving from the third year onward. The real-world validation analysis proved a good agreement between the model and real-world patient records. The highest agreement was found for biologics, where Bayesian analysis estimated an 80.4% probability (95% CI: 72.2%-87.5%) that a decision maker would accept the result as an actual reflection of real-world data. Even where trend data diverged (eg, for surgery [43.1% likelihood of acceptance, 95% CI: 33.7%-52.8%]), the cumulative surgery count over 5 years was within the margin of error of the real-world data. Conclusions: Implementing VCE in the surveillance of patients with Crohn's disease and small bowel involvement may be cost saving in Italy. The congruence between model predictions and real-world patient records supports using this discrete-event simulation to inform healthcare decisions.

Unlocking the Mysteries of the Mishrif Formation: Seismic Data Reinterpretation and Structural Analysis for Reservoir Performance Optimization in the Garraf Oil Field, Southern Iraq

The seismic survey is based on the reflected wave’s inherent nature from the interface among layers, which depends on the layer's density and velocity. This is called acoustic impedance and is used to resolve the confusion associated with the stratigraphic structure of the Mishrif formations in the Garraf oil field. The seismic section of the Garraf oil field in Thi-Qar Province, south of Iraq, was analyzed and interpreted. Considering the most important petroleum accumulation reservoir in the Garraf oil field, to update the structural images of the Mishrif Formation. A seismic study of the actual amplitude reflections, temporal maps, and three-dimensional depositional models demonstrated that the Mishrif Formation generate hydrocarbon from an individual structural trap in the presence of oil. Numerous abrupt discontinuities were observed in the seismic reflectors of the reservoir units of the Mishrif Formation, suggesting either a reef or a fault. The correct probability can be shown by establishing a historical match between the reservoir model and the actual behavior of the reservoir or by running a 3D vertical seismic profile log (VSP), which is more precise than the seismic survey previously used to explore faults.

Designing and Tailoring Optical Properties: Theory and Simulation of Photonic Band Gaps in Photonic Materials

Theoretical calculations and numerical simulations play a crucial role in analyzing material properties and devising effective research strategies. In this study, the photonic band gap (PBG) of polymethyl methacrylate (PMMA) and polystyrene (PS) photonic crystals was successfully predicted using theoretical calculations and numerical simulations. The agreement between the predicted results and the actual reflection peaks reached an impressive level of 99%. Utilizing SEM images, the prediction of reflection peaks in acrylamide (AM)—based photonic hydrogels was conducted using theoretical formulas and Rsoft 2019–Bandsolve software v2019.09. The relationship between the actual reflection peaks and compressive strains in AM-based photonic hydrogels featuring 251 nm PMMA PCs exhibited a remarkable similarity of over 96% with the theoretical and simulated results. In conclusion, an exploration was conducted into the relationship between reflection peaks and compressive strains for AM-based 270 nm PMMA photonic hydrogels, allowing the prediction of the actual reflection peaks under compression. The consistency observed between theoretical/simulated reflection peaks and actual reflection peaks validates the efficacy of this approach in evaluating the optical properties of photonic materials and predicting their responsive effects. This method offers a straightforward and expeditious solution for the design and fabrication of photonic materials.

Rule-making by executive authorities: problems of theory and practice

The article examines problematic issues of rule-making by executive authorities, which are aimed at improving and ensuring the effectiveness of rule-making activities, which is an effective condition for the successful formation of the legal system of Ukraine, taking into account the state-legal reform, as well as the current level of its development.
 When implementing state-legal reform, the needs of rule-making have their own peculiarity, since the legal regulation of social relations cannot be imagined without normative-legal acts of executive authorities. As a result, it can be seen that the main task in this area is to improve and optimize the forms of implementation of their rule-making activities and to determine the degree of legal influence on social relations.
 In Ukraine, until recently, due attention was not paid to the problems of sub-legal norm-making. In some areas, they were covered only fragmentarily. As a result, the practice of implementing rule-making activities remains ineffective, since the activities of executive authorities are largely disorganized, and the creation of a new system is extremely slow and contradictory.
 It was determined that rule-making is a special activity of the state, in the person of specially authorized subjects of power, which are aimed at the normative consolidation of public needs and interests and the provision of appropriate conditions for the realization of the rights and freedoms of citizens and their effective protection, which is carried out by creating a system internally agreed normative legal acts with the aim of increasing the effectiveness of regulation of social relations in Ukraine.
 It is noted that the most fully reveal the content and purpose of the rule-making activity of the executive authorities, its main principles and special features, which contribute to the actual reflection of social regularities in legal prescriptions.
 Proposals regarding the improvement of legal regulation of the rule-making activity of the executive authorities were provided.

Economic-threshold-based classification of soybean aphid, Aphis glycines, infestations in commercial soybean fields using Sentinel-2 satellite data

The soybean aphid (SBA), Aphis glycines Matsumura (Hemiptera: Aphididae), is a significant insect pest of soybean, Glycine max (L.) Merrill (Fabales: Fabaceae), and field treatment decisions for this pest are based on average field populations. Previous studies indicated that ground- and drone-based red-edge and near-infrared remote sensing can be used to detect plant stress caused by SBA infestations in soybean. However, it remains to be determined if remote sensing for SBA can be expanded to field or landscape scale using satellite-based platforms. Thus, this research was conducted in three steps to determine the potential of using Sentinel-2 satellite data for the classification of SBA infestations in soybean fields using simulated and actual Sentinel-2 satellite spectral reflectance. In the first step, as a proof of concept, hyperspectral data from cage studies were used to simulate Sentinel-2 bands and vegetation indices (VIs), conducted in nine trials at multiple locations between 2013 and 2021. The effects of SBA from caged plants on simulated data were evaluated with random intercept linear mixed models. The satellite simulation indicated a significant effect of SBA on the spectral reflectance of caged soybean plants (p < 0.05) for four satellite bands (5, 6, 7, and 8A) and five VIs (NDVI, GNDVI, SAVI, OSAVI, and NDRE). In the second step, actual Sentinel-2 spectral reflectance and corresponding aphid counts of commercial soybean fields, collected from 2017 to 2019, were obtained. The relationship between SBA counts and Sentinel-2 spectral reflectance from commercial soybean fields were evaluated with general linear models. A significant effect of SBA was observed for three satellite bands (6, 7, and 8A) and three VIs (NDVI, SAVI, and OSAVI). In the third step, linear support vector machine (LSVM) models for the classification of SBA infestations as above or below a previously determined economic threshold of 250 aphids per plant were developed using simulated Sentinel-2 bands and VIs from the caged plots, and were tested on actual Sentinel-2 data from commercial soybean fields. The best LSVM model for the classification of aphids in soybean reached 91% accuracy, 85.7% sensitivity, and 93.3% specificity. Thus, simulations with caged plots can be used as an indication of the potential of using satellite data for the detection of plant stresses on a larger scale. Furthermore, this study advances decision-making for SBA, and the developed LSVM model can be used to update regional and local monitoring for the management of SBA.

Physically based illumination correction for sub-centimeter spatial resolution hyperspectral data

Vegetation biophysical- and chemical traits, defined on the basis of leaf area, can be retrieved from their spectral reflectance. Ultra high resolution hyperspectral images, such as ones collected from drones, allows measuring the spectra of individual leaves. The reflectance signal of such data is calibrated with respect to the top-of-canopy (TOC) irradiance, as the local illumination conditions on leaf surfaces are largely unknown and can vary significantly from the TOC conditions. We developed an inversion algorithm that uses the PROSPECT leaf radiative transfer model and the theory of spectral invariants to retrieve the actual leaf reflectance from TOC-calibrated hyperspectral images. Compared with more traditional canopy reflectance models, this approach accounts for the spatial variation in leaf-level irradiance visible in sub-centimeter-resolution images and is computationally more efficient. We used simulated and measured leaf and canopy reflectance data to validate the approach and found the retrieved leaf reflectances to match closely the actual reflectances (relative RMSD was 12% for simulated data on the average and below 10% for measured data). The proposed method provides an efficient approach for illumination correction, enabling reliable, physically based applications for monitoring vegetation biochemical and biophysical properties from ultra-high-resolution spectral imagery.

Medical Application of Big Data: Between Systematic Review and Randomized Controlled Trials

In terms of medical health, we are currently living in the era of data science, which has brought tremendous change. Big data related to healthcare includes medical data, genome data, and lifelog data. Among medical data, public medical data is very important for actual research and medical policy reflection because it has data on a large number of patients and is representative. However, there are many difficulties in actually using such public health big data and designing a study, and conducting systematic review (SR) on the research topic can help a lot in the methodology. In this review, in addition to the importance of research using big data for the public interest, we will introduce important public medical big data in Korea and show how SR can be specifically applied in research using public medical big data.

Large Scale Slave Revolts in Ancient Greece: An Issue of Absence or an Absence of Issue

In the modern perception of the Ancient World the massive slave revolts loom largely. To the modern mind, infused, through education and mass media, with notions of sanctity of personal freedom and shamefulness of servitude, there is natural and immediate connection between the institution of slavery and armed, violent resistance to it. Ancient slaves were kept in obviously shameful and degrading state of bondage, therefore they revolted – they must have. In fact, however, large scale slave revolts are actually quite rare in world history and, in the case of Ancient Greece, all examples that one could point to are late and (at least superficially) marginal. If we limit our scope to Classical Greece (5th and 4th centuries BC), the slave revolt is virtually non-existent, unless we choose to widen the definition of slaves to include the helots of Sparta and the penests of Thessaly. This paper assumes that Messenian (helot) revolts are a separate (though perhaps related) phenomenon to slave revolts, and focus only on the latter. There are only three known cases of anything resembling a slave revolt (four, if we add the problematic case of the slave uprising of Drimacus, in the 3nd century BC Chios), and they seem rather minute in their scope and achievement, especially when compared to the contemporary massive slave wars of Roman Sicily and Italy. The paper argues that this absence is not an illusion, created, as one might argue, through a lack of interest or organized silence on the part of ancient authors, but the actual reflection of historical reality. Prospects of success for such endeavor were minimal, while the dangers involved were overwhelming. Specific conditions required for large scale slave uprisings were rarely met in Ancient Greece and consequently the phenomenon itself was rare.