Bio‐optical properties and estimation of the optically active substances in Lake Tianmuhu in summer

Bio‐optical properties in an optically complex and biologically productive region of Lake Tianmuhu were determined in three cruises from June to August 2006. The concentrations of three optically active substances, tripton C _Tripton (calculated from total suspended matter and chlorophyll‐a (Chla) and phaeophytin‐a (Pa)), phytoplankton pigment C _Chla+Pa , and chromophoric dissolved organic matter (CDOM) a _CDOM(440), were predicted from the estimated irradiance reflectance based on in situ measurements and laboratory analyses. The total relative contributions of phytoplankton, tripton, CDOM and pure water over the range of photosynthetically active radiation (PAR) (400–700 nm) were 36.1%, 24.2%, 15.9% and 23.8%, respectively. The dominant contribution of phytoplankton to the total absorption was due to high phytoplankton pigment concentration. The range and variation in irradiance reflectance and diffuse attenuation coefficient derived from a bio‐optical model, based on inherent optical properties, compared well with the measured variability. A reasonably strong relationship (R² = 0.92) was observed between irradiance reflectance at 780 nm R(780) and C _Tripton. For our data set, the best algorithm for C _Chla+Pa used the three‐band reflectance model [R ^?1(688)?R ^?1(717)]×R(747). The a _CDOM(440) could be estimated using the ratio of irradiance reflectance R(682)/R(555). The retrieval accuracy (R²) of tripton, phytoplankton pigment and CDOM was 0.92, 0.87 and 0.91, respectively, while the rms. error was 0.90 mg l^?1 (18.2%), 3.27 µg l^?1 (14.8%) and 0.073 m^?1 (15.3%), respectively. Estimation of the concentrations of the three optically active substances was reasonably accurate based on inherent optical properties measurement.     

Joint distribution of the number of vertices with given different outdegrees in Galton–Watson forest

A Galton–Watson forest consisting of N roots (or trees) and n   non-root vertices is considered. We study limit distributions of the number of vertices of a given outdegree in such a forest. In this work joint distribution of the number of vertices with the given different outdegrees _r1$r_1$ and _r2$r_2$ is considered. A local limit theorem for this characteristic is proved.     

Sniffer-Net: quantitative evaluation of smoke in the wild based on spatial–temporal motion spectrum

Smoke detection plays an essential role in the wild video surveillance systems for abnormal events warning. In this paper, we introduced a dedicated neural network structure named Sniffer-Net to simultaneously extract smoke dynamic feature robustly and evaluate the smoke concentration accurately. Firstly, we utilize an improved LiteFlowNet to estimate the global optical flow from image sequence. Meanwhile, a Marr–Hildreth method is brought up and fused into this network to distinguish and eliminate occluded regions from global flow map. Then, an evaluation module based on Context-Encoder network is put forward specially to quantify smoke concentration levels. This network, following the improved LiteFlowNet, is modified through replacing the loss function and removing the multiscale scheme and trained to infer approximate smoke optical flow behind occlusion regions. Starting from the statistical view, the irregular RGB/HSV feature spaces are converted into a specific quantitative evaluation space. As a result, the whole evaluation system is responsible to transform the distribution of irregular smoke motion feature into a quantified form of representation. In turn, this transformation endows the system with a novel numerical standard for smoke concentration evaluation. Finally, an accuracy assessment method is applied to compare the results of detected smoke concentration with the human experience prior model, which feedback the accuracy and false detection rate of system algorithm. In the experiments of five smoke datasets, our proposed smoke detection approach is superior to other state-of-the-art methods, and concentration algorithm achieves the satisfactory performance of 97.3% accuracy on some specialized dataset.

     

Evaluation of the B‐method for determining actual evapotranspiration in a boreal forest from MODIS data

Boreal forests occupy about 11% of the terrestrial surface and represent an important contribution to global energy balance. The ground measurement of daily evapotranspiration (LE_d) is very difficult due to the limitations on experiments. The objective of this paper is to present and explore the applicability of the B‐method for monitoring actual LE_d in these ecosystems. The method shown in this paper allows us to determine the surface fluxes over boreal forests on a daily basis from instantaneous information registered in a conventional meteorological tower, as well as the canopy temperature (T _c) retrieved by satellite. Images collected by the MODIS (moderate resolution imaging spectroradiometer) on board EOS‐Terra have been used for this study. The parameters of the model were calibrated from the SIFLEX‐2002 (Solar Induced Fluorescence Experiment 2002) campaign dataset in a northern boreal forest in Finland. A study of these parameters was made on an hourly basis in order to make the method applicable, not only at midday but within an interval of 7 h around it. This is an important advance with respect to the original formulation of this approach since the overpass time of satellites can be very variable. The comparison between T _c ground measured with a thermal infrared radiometer, and T _c retrieved from land surface temperature (LST) MODIS data, showed an estimation error of ±1.4°C for viewing angles from 5 to 60°. A complete sensitivity analysis was carried out and an estimation error of about ±35%, corresponding to the interval 10.00–11.00 h UTC, was shown as the lowest in LE_d retrieval. Finally, the method was validated over the study site using 21 MODIS images for 2002 and 2003. The results were compared with eddy‐correlation ground measurements. An accuracy of ±1.0 mm/day and an overestimation of 0.3 mm/day were shown in the LE_d retrieval.     

Time–frequency distributions in the classification of epilepsy from EEG signals

In this paper we propose a novel recognition algorithm for the discrimination of epilepsy based on electroencephalogram (EEG) signals. We validate the algorithm on a benchmark dataset in order to compare the algorithm with other algorithms in the literature. More specifically, features were extracted from the bilinear time–frequency distributions (TFD) of the EEG signal. A one-against-one decomposition is used to break the multi-class problem into binary subproblems solvable with a support vector machine (SVM). The decomposition permitted binary subproblem-dependent feature libraries to be constructed from biologically inspired features derived from conditional moments calculated from EEG TFD. This results in a flexible, class-dependent feature selection based on a forward selection wrapper representing a departure from prior work which tends to utilize the same set of features to delineate all classes. We investigated the sensitivity of the classification accuracy to changes in the proportion of data used to train the algorithm. It was found that the distribution of classification accuracies was statistically similar over a range of proportions of data used to train the algorithm. This served to validate our algorithm in a statistical sense and represents a significant departure from literature, which tends to report only the best result for a given classification algorithm. To the best of our knowledge, the newly introduced algorithm is able to outperform the best reported accuracy in literature for the problem considered in this paper.     

Experimental and thermodynamic study of the role of titanium in the microstructural and thermal properties of cast Ni–Cr–C–Ti alloys

Three compositions of the {Ni–25Cr–0.25 or 0.50C–1 or 2Ti}-type were studied by thermodynamic calculations for anticipating their melting temperature ranges and their microstructures at 1200 °C. In parallel the corresponding alloys were synthesized by classical foundry and subjected to Differential Thermal Analysis and exposures at 1200 °C followed by metallographic characterization. Calculations and experiments are globally consistent concerning the melting range temperatures, the microstructures in the as-cast state and after aging at 1200 °C. Good agreement was also found concerning the carbides fractions and the matrixes’ chemical compositions.     

Optical parametric oscillators in lidar sounding of trace atmospheric gases in the 3–4 μm spectral range

Applicability of a KTA crystal-based laser system with optical parametric generation to lidar sounding of the atmosphere in the spectral range 3–4 μm is studied in this work. A technique developed for lidar sounding of trace atmospheric gases is based on differential absorption lidar (DIAL) technique and differential optical absorption spectroscopy (DOAS). The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases.     

Ion–π interaction in impacting the nonlinear optical properties of ion–buckybowl complexes

Ion–buckybowl complexes have received considerable attention in modern chemical research due to its fundamental and practical importance. Herein, we performed density functional theory (DFT) to calculate the geometical structure, binding interactions, dipole moments and the first hyperpolarizabilities (β_tot) of ion–buckybowl complexes (ions are Cl⁻ and Na⁺, buckybowls are quadrannulene, corannulene and sumanene). It is found that the stabilities of ion–buckybowl compounds primarily originate from the interaction energy, which was proved by a new isomerization energy decomposition analysis approach. Plots of reduced density gradient mirror the ion–π weak interaction has been formed between the ions and buckybowls. Significantly, the buckybowl subunits cannot effectively impact the nonlinear optical (NLO), but the kind of ion has marked influence on the second-order NLO responses. The β_tot values of Cl⁻–buckybowl complexes are all larger as compared to that of Na⁺–buckybowl complexes, which is attributed to the large charge-transfer (CT) from Cl⁻ to buckybowl. Our present work will be beneficial for further theoretical and experimental studies on the NLO properties of ion–buckybowl compounds.     

The anomalous behavior and properties of Ni–Co films codeposited in the sulfamate-chloride electrolyte

In this paper, we have studied the effect of controlled parameters on the anomalous behavior and property of the codeposited nickel-cobalt (Ni–Co) films in the complex sulfamate-chloride bath. The variation of current densities and temperature resulted in different Co atomic percentage (Co at%) of the deposited films as well as the morphology and microhardness. Co at% in Ni–Co films gradually decreased with increasing current density and temperatures with variation from approximately 25 to 15%. The Co participation could also inhibit grain growth of the deposited films. The Ni–Co film codeposited at lower current density or temperature would have the higher hard Co content and smaller grain which results in the higher microharness and smooth morphology.     

The evolution of knowledge-based engineering from a design research perspective: Literature review 2012–2021

Knowledge-based engineering (KBE) is a research field, which evolved in the 1980s within the context of artificial intelligence (AI), computer aided design (CAD) and computer programming. KBE is often referred to methods, processes and tools for knowledge reuse and design automation promising time and cost benefits in engineering design and originally especially in aerospace and automotive industry. Despite the long period of existence, theoretical foundations of KBE are weak and scientific literature is quite dispersed. About a decade ago, a review by Verhagen et al. collected the state of research and identified future research challenges, which has gained impact within the KBE research community. Therefore, within our review we aim at analysing the evolution of those research challenges in KBE literature during the last decade and further provide an overview of current shortcomings from a design research perspective. The analysis comprises 160 publications from the period of 2012 to 2021. Key findings from the review show, that the challenges from 2012 remain unsolved. We further derived that reuse and adoption of KBE approaches from literature is impeded by (1) a missing conceptualization of KBE research, (2) insufficient links from knowledge source to automation and (3) a tendency of insufficient distinction of the application area.     

Assessment of stand‐wise stem volume retrieval in boreal forest from JERS‐1 L‐band SAR backscatter

JERS‐1 L‐band SAR backscatter from test sites in Sweden, Finland and Siberia has been investigated to determine the accuracy level achievable in the boreal zone for stand‐wise forest stem volume retrieval using a model‐based approach. The extensive ground‐data and SAR imagery datasets available allowed analysis of the backscatter temporal dynamics. In dense forests the backscatter primarily depended on the frozen/unfrozen state of the canopy, showing a ～4 dB difference. In sparse forests, the backscatter depended primarily on the dielectric properties of the forest floor, showing smaller differences throughout the year. Backscatter modelling as a function of stem volume was carried out by means of a simple L‐band Water Cloud related scattering model. At each test site, the model fitted the measurements used for training irrespective of the weather conditions. Of the three a priori unknown model parameters, the forest transmissivity coefficient was most affected by seasonal conditions and test site specific features (stand structure, forest management, etc.). Several factors determined the coefficient's estimate, namely weather conditions at acquisition, structural heterogeneities of the forest stands within a test site, forest management practice and ground data accuracy. Stem volume retrieval was strongly influenced by these factors. It performed best under unfrozen conditions and results were temporally consistent. Multi‐temporal combination of single‐image estimates eliminated outliers and slightly decreased the estimation error. Retrieved and measured stem volumes were in good agreement up to maximum levels in Sweden and Finland. For the intensively managed test site in Sweden a 25% relative rms error was obtained. Higher errors were achieved in the larger and more heterogeneous forest test sites in Siberia. Hence, L‐band backscatter can be considered a good candidate for stand‐wise stem volume retrieval in boreal forest, although the forest site conditions play a fundamental role for the final accuracy.     

Quantification of interacting runtime qualities in software architectures: Insights from transaction processing in client–server architectures

ContextArchitecture is fundamental for fulfilling requirements related to the non-functional behavior of a software system such as the quality requirement that response time does not degrade to a point where it is noticeable. Approaches like the Architecture Tradeoff Analysis Method (ATAM) combine qualitative analysis heuristics (e.g. scenarios) for one or more quality metrics with quantitative analyses. A quantitative analysis evaluates a single metric such as response time. However, since quality metrics interact with each other, a change in the architecture can affect unpredictably multiple quality metrics.ObjectiveThis paper introduces a quantitative method that determines the impact of a design change on multiple metrics, thus reducing the risks in architecture design. As a proof of concept, the method is applied on a simulation model of transaction processing in client server architecture.MethodFactor analysis is used to unveil latent (i.e. not directly measurable) quality features represented by new variables that reflect architecture-specific correlations between metrics. Separate Analyses of Variance (ANOVA) are then applied to these variables, for interpreting the tradeoffs detected by factor analysis in terms of the quantified metrics.ResultsThe results for the examined transaction processing architecture show three latent quality features, the corresponding groups of strongly correlated quality metrics and the impact of architecture characteristics on the latent quality features.ConclusionThe proposed method is a systematic way for relating the variability of quality metrics and the implied tradeoffs to specific architecture characteristics.     

Topology analysis of manufacturing service supply–demand hyper-network considering QoS properties in the cloud manufacturing system

Cloud Manufacturing (CMfg), a new manufacturing paradigm, enables an opportunity for manufacturing enterprises to respond to a wide variety of demands. The CMfg concept integrates the distributed resources and capacities in a shared economy, transfers them to the virtual manufacturing services with various quality of service (QoS) properties. These services are invoked to collaborate in producing customized demands with specific functional and non-functional properties. The operational perspective of the service-demand matching problem is considered more in the literature; however, it is a challenging problem in the CMfg ecosystem. This paper evaluates the service-demand matching problem from a structural perspective to facilitate resilience and configurable system working well in the operational interactions. Therefore, a CMfg hyper-network-based model is proposed which is enriched with QoS properties. It employs the available capacities in all small and medium enterprises (SMEs) and large companies. The service-demand matching problem is a complex issue; so, it is impossible to analyze it with the current approaches. Here, the CMfg structure is examined through topological characteristics. It helps decision-makers to provide a robust and resilient service-demand matching model. It also proposes some investment opportunities for the SME. The proposed model and its capabilities are discussed through a real case study about the COVID-19 ventilator manufacturing systems in CMfg ecosystem.     

The application of a binary division procedure to the classification of forest subcategories using MODIS time-series data during 2000–2010 in China

Forests account for more than 23% of China’s total area. As the most important terrestrial ecosystem, forests have tremendous ecological value. However, it remains difficult to classify forest subcategories at the national scale. In this study, a newly developed binary division procedure was used to categorize forest areas, including their spatiotemporal dynamics, during the period 2000–2010. Time-series images acquired using the Moderate Resolution Imaging Spectroradiometer (MODIS), together with auxiliary data on land use, climate zoning, and topography, were utilized. Hierarchical classification and zoning were combined with remote-sensing auto-classification. Based on the forest extent mask, the state-level forest system was divided into four classes and 18 subcategories. The method achieved an acceptable overall accuracy of 73.1%, based on a comparison to the sample points of China’s fourth forest general survey data set. In 2010, the total forest area was 1.755 × 10⁶ km², and the total area of and shrubs was 4.885 × 10⁵ km². The total area of woodland increased by 2536.25 km² during the decade 2000–2010. The shrub subcategories exhibited almost no change during this time period; however, significant changes in forest area occurred in the mountainous region of Northeast China as well as in the hilly regions of Southern China. The main transformations took place in cold-temperate and temperate mountainous deciduous coniferous forest, subtropical deciduous coniferous forest, subtropical evergreen coniferous forest, and temperate and subtropical deciduous broadleaved mixed forests. The binary division procedure proposed herein can be used not only to rapidly classify more forest subcategories and monitor their dynamic changes, but also to improve the classification accuracy compared with global and national land-cover maps.     

De-coding Our Scholarship: The State of Research in Computers and Writing from 2003–2008

Since its inception, the field of computers and writing has responded to rapid technological advancements that affect the research, practice, and teaching of writing. A potential consequence of addressing these advancements in teaching and practice, however, may be a reduced focus on foundational, empirical research. To examine the state of research in the field of computers and writing, we assessed the types of research published in four journals (Computers and Composition print, Computers and Composition Online, Kairos, and College Composition and Communication (CCC)) from late 2003/early 2004 to the end of 2008. We explored the state of research by investigating research approaches, design, and modes of inquiry over time. Within this context, we considered author gender, collaboration, and employment of interdisciplinary and mixed methods. We applied criteria from MacNealy (1998) to classify 26% of the computers and writing articles we analyzed as rigorous empirical research. We found a preference for qualitative research designs (56% of articles were qualitative) and, to a lesser degree, mixed methods (29%). While providing a sense of the state of the field as it matures, we conclude by presenting discussion questions on the role of research, research drivers, and ways to increase the quality of research and research reporting. We urge the field to consider the kinds of research we do, teach, and value.     

Experimental study of thermodynamic properties and phase equilibria in Na2CO3–K2CO3 system

Sodium and potassium carbonates and their mixtures are important for different applications, e.g. for latent thermal energy storage, die-casting processes and molten carbonate fuel cells. In this work the phase diagram and thermodynamic properties of Na₂CO₃–K₂CO₃ system were studied by differential thermal analysis, differential scanning calorimetry and high temperature X-ray diffraction. Three carbonate mixtures (56, 25 and 75 mol% of Na₂CO₃) have solid-solid transition in a wide temperature range between 648 K and 823 K. The high temperature XRD analysis has shown that this transition is a continuous process of changing of the unit cell volume without structural changing of the hexagonal lattice. This phenomenon has also been observed on the measured heat capacity curves. The obtained experimental results were compared with calculations performed using the previous thermodynamic datasets. The comparison of these results shows that further thermochemical assessment of this system needs to be performed to achieve better agreement with the available experimental data.     

HCO-TERNARY: A FORTRAN code for calculating P–V–T–X properties and liquid vapor equilibria of fluids in the system H2O–CO2–CH4

The equation of state (EOS) for the system H₂O–CO₂–CH₄ was programmed in a FORTRAN code which allows for its utilization in several modes. In one mode, specifically designed for mathematical modeling of two-phase, two-component flow, the code accepts as independent variables (1) pressure and (2) the composition of the gas phase. Other modes allow for the calculation of phase equilibria and/or the molar volumes of H₂O and binary mixtures, with pressure and temperature as the input variables (just pressure in the case of H₂O). Another mode is used to calculate phase equilibria for ternary mixtures, with pressure, temperature and the mole fraction of water in the gas phase as input variables. The algorithms for automatic convergence utilized in each mode are described.The code was tested extensively against experimental data from the literature. Some of these data were applied in the development of the EOS, and others were published subsequently. Analyses of the performance of the code and EOS for the modes described above, in the range 50–1000°C, 0–1000 bar, are presented. P–T–X regions of best applicability of the code and EOS are also identified.     

Analysis of collocated AIRS and MODIS data: a global investigation of correlations between clouds and atmosphere in 2004–2012

We used collocated observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS) to investigate correlations between cloud parameters and atmospheric stability. We focus on low clouds and specifically investigate the cloud parameters cloud cover and cloud optical thickness from MODIS. The selected atmospheric parameters from AIRS are maximum relative humidity (MRH), lower tropospheric stability (LTS), and water vapour gradient (QTS). The correlations were tested for temporal and regional variation on a global scale and over a time frame of 10 years. Cloud cover and MRH show weak correlations and strong variations on both the temporal and spatial scales. However, cloud cover and lower tropospheric stability show a high correlation in areas with low maritime clouds. The correlation is relatively stable, but slightly increased for the years 2009–2012. Correlations between cloud cover and QTS show a similar behaviour, but slightly stronger variations on the spatial and temporal scales, with better correlations in the East Pacific and from 2004 to 2012. The correlations with cloud optical thickness are weaker in all three cases. A more detailed analysis of the Southeast Pacific shows the influence of El Niño Southern Oscillation (ENSO) on most parameters, but a relatively stable behaviour for the connection of cloud fraction and LTS. Based on the analysis, we suggest that relative humidity is an insufficient approach to link atmospheric properties and low cloud cover. However, we find good correlations with respect to LTS and QTS. LTS in particular indicates low temporal fluctuations, even in the case of influence by ENSO.     

Automatic Extraction of Rules for Anaphora Resolution of Japanese Zero Pronouns in Japanese–English Machine Translation from Aligned Sentence Pairs

This paper proposes a method to extract rules for the anaphora resolution of Japanese zero pronouns in Japanese–English MT from aligned sentence pairs. After aligned sentence pairs unsuitable for rule extraction because of analysis errors or free translations are automatically rejected, zero pronouns in the Japanese sentences and the English translation equivalents of their antecedents are extracted from the remaining Japanese and English aligned sentence pairs using ten hand-developed alignment rules. This method identifies all Japanese zero pronouns whose translation equivalents are not explicitly expressed in an English sentence, this method identifies these as unalignable. Then, resolution rules for the remaining zero pronouns are automatically extracted using the aligned pairs, equivalent word/phrase pairs extracted from the aligned sentence pairs, and the syntactic and semantic structures of the Japanese sentences. This method was implemented in a Japanese–English MT system, ALT-J/E. 98.4% of all pairs were automatically aligned correctly in a window test, and 94.0% in a blind test. Furthermore, extracted rules for zero pronouns with deictic references created automatically from sentence pairs correctly resolved 99.0% of the zero pronouns in a window test and 85.0% of the zero pronouns in a blind test.