Values Of Quantities Research Articles

Skeleton curve and phantom node method for the Thick Level Set approach to fracture

The Thick Level Set method (TLS) is an approach for non-local damage modeling in which the damage evolution is linked to the movement of a damage front described with the level set method. More recently, a new version of the TLS, designated as the TLSV2, has been proposed as a new concept for coupling continuum damage modeling and discrete cohesive crack modeling for failure analysis in solids. The main objective of this new framework is to profit from both modeling approaches. The continuum part allows for handling crack initiation, branching and merging, whereas the cohesive part brings the capability to handle discrete cracks with large crack opening or sliding without heavily distorted elements, and with the possibility to model stiffness recovery upon contact. In this paper, a generalized framework for the TLSV2 is introduced. Two major issues with the TLSV2 method that have not been dealt with since its inception are addressed in this study, and solutions are proposed. Firstly, the method depends on the location of skeleton curve of the level set field, on which the discontinuity in the displacement field is evaluated. The problem of locating the skeleton curve can be a complicated task, mainly because topological events may emerge as the analysis progresses, such as crack branching. The skeleton curve is determined through a combination of ball-shrinking and graph-based algorithms and then mapped onto the finite element mesh. Secondly, the cohesive forces and displacement discontinuity of the TLSV2 are modeled using the phantom node method. Furthermore, a new approach to compute the averaged values of local quantities is introduced, and model calibration is discussed. The degree of stiffness recovery under compression that is still needed for the continuum part is investigated. Numerical experiments demonstrate the accuracy and ability of the proposed model to handle simulation of failure analysis presenting complex topological crack patterns.

PCDD/Fs from a large-scale municipal solid waste incinerator under transient operations: Insight formation pathways and optimal reduction strategies

Polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) emissions from the transient operation of municipal solid waste incinerators can reach up to 690 ng/Nm3, as measured in this study. To control the extreme emissions to meet the national standard, the formation pathways of PCDD/F were investigated under transient operations (cold start-up, hot start-up, and after start-up) and normal operations. Compared with normal operations, transient operations facilitate the formation of low-chlorinated congeners rather than highly chlorinated congeners. Statistically, for transient operations, strong correlations were found among tetrachlorodibenzo-p-dioxin or tetrachlorodibenzofuran isomers. An abundant carbon matrix is an important carbon source for PCDD formation. Moreover, the comprehensive study revealed that the oxidation of deposited soot is the main source of PCDD/F emissions, relative to de novo synthesis, chlorobenzene-route synthesis, chlorophenol-route synthesis, and chlorination of dibenzo-p-dioxin/dibenzofuran. In addition, the optimal start-up procedure was constructed by analyzing main formation pathways and operating conditions. The relationship between the international toxic quantity (I-TEQ) values (CI-TEQ) and the reaction time can be assigned as CI-TEQ = 11.72t−0.65 (R2 = 0.97) for the circulating fluidized bed. The relationship of CI-TEQ = 4.61t−0.59 (R2 = 0.85) was also proven on the dataset with a grate furnace. Then, the optimal feeding rate of activated carbon was further proposed by the relationship between the reaction time and I-TEQ, and the semi-empirical equation for PCDD/Fs adsorption. Finally, the PCDD/Fs emissions can be reduced to 0.1 ng I-TEQ/Nm3 under transient operations according to the time since start-up.

Two Methods to Improve the Efficiency of Supersonic Flow Simulation on Unstructured Grids

The paper presents two methods to improve the efficiency of supersonic flow simulation using arbitrarily shaped unstructured grids. The first method promotes increasing the numerical solution convergence rate and is based on the geometric multigrid method for initialization of the flow field. The method is used to obtain the initial field of distributed physical quantity values, which maximally corresponds to the converged solution. For this purpose, the problem simulation is performed on a series of coarse grids beginning from the coarsest one in this series. Upon completion of simulations, the solution obtained is interpolated to a finer grid and used for initialization of simulations on this grid. The second method allows increasing the numerical solution accuracy and is based on statically adapting the computational grid to the flow specifics. The static adaptation algorithm provides automatic refinement of the computational grid in the region of specific features of flow, such as shock waves typical for supersonic flows. This algorithm provides a better description of the shock-wave front owing to the local grid refinement, with the local refinement region being automatically selected. Results of using these methods are demonstrated for the two supersonic aerodynamics problems: the simulation of the bow shock strength at a given distance under axially symmetric body Seeb-ALR and a mock-up aircraft Lockheed Martin 1021. It is shown that in both cases, the numerical solution convergence rate is increased owing to the use of the geometric multigrid method for initialization and a higher quality and a higher accuracy of solution is gained owing to the local grid refinement (using static adaptation means) near the shock-wave front.

Automated system for regulating the thermal parameters of cord heat treatment furnaces with optimization of the gas-to-air ratio at a certain value

The system of automation which allows to control autonomous use of gas with preserva-tion of quality of technological process is resulted. The given algorithm, corresponding programs, technical means of automation system carry out regulation of air expenses at any values of quantity of fuel (gas). The gas-to-air ratio is determined experimentally from the analysis of exhaust gases for a specific type of furnace. The control algorithm is implemented using a microprocessor controller, and includes: PID control - law (proportional-integral-differential), linearization, which processes the input values of gas and air and reduces measurement errors of flow sensors and especially in the initial part of the sensor range; piecewise linear approximation, which allows: to implement the specified dependence of the ratios, flexibility and the ability to adjust and change the parameters of the control circuits, which adapts the control system to specific production conditions. The controllers can be configured both at the lower level of the distributed ACS TP and communicate with the upper level through the digital serial communication channel, and used as a stand-alone device. The meter of the measured and calculated parameters of the corresponding physical quantities displays them on the matrix board of its front panel. A computer with a printer located on the panel shop is connected to the meters. Devel-oped programs that implement control algorithms written in Delphi 3.0 using BDE (Bor-landDatabaseEnqine). Technological programs and a set of documentation for the operation of the system have also been developed. The system is focused on daily work in conjunction with meter gauges. Instrument read-ings are taken at intervals of one to one hundred and twenty minutes, depending on the settings made on the front panel. Information from the meters is stored in the database "Infoterm.db", as well as in the archival database "Archive.db". Moreover, the database "Infoterm.db" is released from the data every day before the launch of system programs. The technological program for heat meters is made on the basis of preliminary calcula-tions of measuring diaphragms from the manufacturer with observance of metrological and technological conditions (metrological certification, etc.). If necessary, the software is configured.

Current-voltage curves of planar heterojunction perovskite solar cells – Novel expressions based on Lambert W function and Special Trans Function Theory

IntroductionAt the present time, much attention has been focused on new types of solar cells, called perovskite solar cells. They are highly efficient devices with more than 25% power conversion efficiency. However, perovskite solar cell performance has not yet been fully explored. ObjectivesWe aimed to mathematically investigate the analytical modeling of current–voltage curves of planar heterojunction perovskite solar cells using Perovich Special Trans Function Theory (STFT). Furthermore, we proposed novel analytical closed-form solutions for short-circuit current and open-circuit voltage of these cells in terms of STFT. We evaluated the safety for laying the theoretical foundation by comparing the accuracy of the proposed expressions by the known methods. MethodsA novel hybrid metaheuristic algorithm, called particle swarm optimization (PSO) – evaporation rate water cycle algorithm (ERWCA), is proposed to determine equivalent circuit parameters of the perovskite solar cell. A novel objective function is introduced for estimating the parameters for that purpose too. ResultsIt was shown that STFT is very applicable and efficient for representing current–voltage expressions of perovskite solar cells. STFT provides a more accurate solution and requires fewer order members than the solutions provided by the conventional Taylor series. Based on these expressions and numerical calculations, it is verified that the characteristic values ​​of variables (short-circuit current, no-load voltage, efficiency, and fill factor) were not accurately calculated in the literature. Also, parameters of equivalent circuits of these cells were not accurately estimated. The equivalent circuit parameters were determined using the algorithm proposed in this work, which fit the verified values ​​of characteristic quantities much better than the literature. ConclusionThis work lays the foundation for developing the planar-structured perovskite solar cell models, in which the proposed estimation method and expressions are highly effective and provide excellent results.

Development of a non-local approach for life prediction of notched specimen considering stress/strain gradient and elastic-plastic fatigue damage

In this study, a non-local approach is developed for the fatigue life prediction of notched specimens, considering stress/strain gradient and elastic-plastic fatigue damage. The damage coupled constitutive models are presented to model the mechanical behavior of material. The critical plane method and triaxiality factor are employed to determine the location of the couple point. The gradient values of mechanical quantities are then computed, and the modified coefficients in damage models are acquired. The numerical simulations are implemented to compute the damage evolution process and predict fatigue life. Meanwhile, the coupling effects between stress field and damage field are considered. The predicted results are verified by experimental data, and also compared with the local method. Finally, the influence of stress concentration factor, shape of notch, and cyclic variation of stress/strain gradient are further investigated.

Economics of Oil Seed Exports in India: An Application of Holt-Forecasts

This article intended to examine the export performance of oil seed crops in India from 1987 to 2019 using the Compound Annual Growth Rate (CAGR), Cuddy-Della Valle instability index, as well as forecast export quantity and value to 2025. The analysis focuses mainly on two major oil seed crops: groundnut and soyabean. The research of oil seed crop export growth trends over time revealed a positive growth rate for both export quantity and export unit value. The potential for Indian oil seed crop in the world market during the post-liberalization period were shown by the strong growth rates of soyabean goods combined with high export instability indices. When compared to soyabean, the annual growth rate of groundnut was the lowest, with instability showing a wide range across the entire period. Holt models were created in this paper to estimate oil seed export quantity and prices, with the top models chosen by comparing Akaike Information Criteria (AIC), Mean Absolute Percent Error (MAPE). Further, groundnut export quantity and price forecasts showed positive development throughout the forecast period, whereas, soyabean export price forecasts showed a 0.01 percent increase from 2021 to 2025. To improve the worldwide performance of the Indian oil seed industry, the government should make appropriate amendments to oil seed export policies and domestic supportive measures, as well as adopt appropriate value adds and market diversification strategies.

Molecular dynamics simulation or structure refinement of proteins: are solvent molecules required? A case study using hen lysozyme

In protein simulation or structure refinement based on values of observable quantities measured in (aqueous) solution, solvent (water) molecules may be explicitly treated, omitted, or represented by a potential of mean-solvation-force term, depending on protein coordinates only, in the force field used. These three approaches are compared for hen egg white lysozyme (HEWL). This 129-residue non-spherical protein contains a variety of secondary-structure elements, and ample experimental data are available: 1630 atom–atom Nuclear Overhauser Enhancement (NOE) upper distance bounds, 213 3 J-couplings and 200 S2 order parameters. These data are used to compare the performance of the three approaches. It is found that a molecular dynamics (MD) simulation in explicit water approximates the experimental data much better than stochastic dynamics (SD) simulation in vacuo without or with a solvent-accessible-surface-area (SASA) implicit-solvation term added to the force field. This is due to the missing energetic and entropic contributions and hydrogen-bonding capacities of the water molecules and the missing dielectric screening effect of this high-permittivity solvent. Omission of explicit water molecules leads to compaction of the protein, an increased internal strain, distortion of exposed loop and turn regions and excessive intra-protein hydrogen bonding. As a consequence, the conformation and dynamics of groups on the surface of the protein, which may play a key role in protein–protein interactions or ligand or substrate binding, may be incorrectly modelled. It is thus recommended to include water molecules explicitly in structure refinement of proteins in aqueous solution based on nuclear magnetic resonance (NMR) or other experimentally measured data.

Characterization of grazing behaviour microstructure using point-of-view cameras.

Grazing patterns, intake structure, and diet selection are dynamic responses to animals’ feeding environment. This study uses video sequences from animal-borne cameras to capture time- and scale-dependent grazing behaviour variables related to sward explanatory conditions. We observed grazing ‘through’ the sheep’s eyes using point-of-view (POV) cameras coupled with event logging software. Time-specific sward features were measured by sampling ‘really’ grazed patches identified by applying a global navigation satellite system (GNSS) precision-grazing approach. Sward variables on a Mediterranean native sward were measured for two years during the active spring plant-growth cycle. Overall, the results demonstrate that POV cameras were able to capture grazing behaviour fine-tuning to changes in sward characteristics. Sheep compensate for the decrease in sward quantity and nutritive value by increasing the size and duration at each behavioural scale (i.e., meal, bout, and station) while increasing the bout rate and decreasing the station rate. Diet composition also changed as sward matured. The proportion of forbs in the diet remained high in early and late spring, and forbs and legumes were preferred to grasses in early spring. Grazing selectivity was more pronounced in late spring, with sheep favouring the middle stratum of the sward’s vertical structure, preferring green vegetative material, while enlarging the feeding niches’ span and spending more time at each niche, consequently reducing the station rate. Although data collected by individual animal-borne POV cameras were representative of the flock behaviour, they may underestimate the total grazing time outside major meals. The results indicate that the use of animal-borne video cameras is suitable for assessing variations in sheep grazing behaviour patterns in complex swards.

Quasiprobabilities of work and heat in an open quantum system

We discuss an approach to determine averages of the work, dissipated heat, and variation of internal energy of an open quantum system driven by an external classical field. These quantities are measured by coupling the quantum system to a quantum detector at different times. This approach allows us to preserve the full quantum features of the evolution. From the measured phase, we are able to obtain a quasicharacteristic function and a quasiprobability density function for the corresponding observables. Despite the fact that these quasiprobability density functions are not the results of direct measurements, they reproduce the expected value of the physical quantities. Analogously to the Wigner function, the negative regions of these quasiprobability density functions are directly related to pure quantum processes which are not interpretable in classical terms. We use this feature to show that in the limit of fast dissipation, the quantum features vanish and interpret this as the emergence of the classical limit of the energy exchange process. Our analysis explains and confirms the behavior observed in recent experiments performed on IBMQ devices [P. Solinas et al., Phys. Rev. A 103, L060202 (2021)]. The possibility to discriminate between classical and quantum features makes the proposed approach an excellent tool to determine if, and in which conditions, quantum effects can be exploited to increase the efficiency in an energy exchange process at the quantum level.

The overcontact binary SS arietis

New radial velocity and photometric data for SS Ari have been obtained and analysed using the 2003 versions of the Wilson-Devinney code. Values for fundamental quantities have been obtained: M1 = 0.510 (15) M ʘ, M 2 = 1.521 (26) M ʘ, R1 = 0.87 (2) Rʘ, R2 = 1.42 (2) Rʘ, L1 = 0.88 (8) L ʘ, and L 2 = 2.13 (21) L ʘ. In addition to the values provided by the Wilson-Devinney output, luminosities have been computed directly using photometry from APASS, the Gaia distance, and estimates of the interstellar absorption. Although the two sets of luminosities compare well, the accuracy of the latter set is limited by the uncertainty in the APASS magnitudes. Although the TYC magnitudes for the comparison star are more precise, they produce higher luminosities (but still within error limits). In any case, the good agreement between the luminosities determined by the two methods suggests that they, and all other results in this paper, might be more reliable than previous values in the literature. Inserting the parameters into a Log(L)-Log(Teff) plot for each star using data from Yakut and Eggleton (2005) suggests that the more massive star is somewhat over-luminous and therefore evolved, whereas its companion is under-luminous. Analysis of the period behaviour with the aid of an eclipse timing difference (OC) plot reveals that the double sine relationship Kim et al. (2003) is no longer valid. A new LiTE relationship adding two companion stars has been obtained, but, in view of the fact the putative period of one of them is in the range of ∼600 years, the relationship must be regarded as very tentative indeed.

Asymptotic Behavior and Typicality Properties of Runlength-Limited Sequences

This paper studies properties of binary runlength-limited sequences with additional constraints on their Hamming weight and/or their number of runs of identical symbols. An algebraic and a probabilistic (entropic) characterization of the exponential growth rate of the number of such sequences, i.e., their information capacity, are obtained by using the methods of multivariate analytic combinatorics, and properties of the capacity as a function of its parameters are stated. The second-order term in the asymptotic expansion of the rate of these sequences is also given, and the typical values of the relevant quantities are derived. Several applications of the results are illustrated, including bounds on codes for weight-preserving and run-preserving channels (e.g., the run-preserving insertion-deletion channel), a sphere-packing bound for channels with sparse error patterns, and the asymptotics of constant-weight sub-block constrained sequences. In addition, the asymptotics of a closely related notion -- $ q $-ary sequences with fixed Manhattan weight -- is briefly discussed, and an application in coding for molecular timing channels is illustrated.

Stability research of Xiaoer Ganmaoning Oral Liquid based on chromatographic peak matching and image sensory evaluation

The high performance liquid chromatography(HPLC) characteristic chromatogram of Xiaoer Ganmaoning Oral Liquid(oral liquid for short) was established. The medicinal materials corresponding to characteristic peaks, their index components and ranges of similarity with the reference chromatograms were clarified. The similarity between the characteristic chromatograms of 10 batches of the oral liquid and the reference chromatogram was higher than 0.994. Eighteen characteristic peaks were identified, which were derived from different medicinal materials including Scutellariae Radix, Arctii Fructus, Lonicerae Japonicae Flos, Gardeniae Fructus and Forsythiae Fructus. Further, 11 characteristic peaks were assigned by the comparison with reference substances as chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, isochlorogenic acid A, isochlorogenic acid C, baicalin, baicalein, wogonin, scutellarin, forsythiaside A and arctiin. Also, the characteristic chromatogram of precipitate in the oral liquid was established, and the similarity between characteristic chromatograms of 10 batches of the precipitate and the reference chromatogram was higher than 0.940. The 14 characteristic peaks originating from the precipitate and those from the oral liquid were consistent in retention time, and the content of all index components in the precipitate was lower than 5% of that in the oral liquid. Moreover, the stability of precipitate during the accelerated stability test was explored with filtration and Matlab-based image sensory evaluation. The precipitate mass and precipitation degree both increased over the stability test duration significantly. The stability of the oral liquid was used as a model system in this study to establish the integrated quality control system which related to medicinal materials, preparations and precipitate with HPLC characteristic chromatograms and image sensory evaluation, which lays a foundation for the exploration of the quantity value transfer of the oral liquid.

Development of metrological support for nucleic acid measurements

Measurements of nucleic acid have become an essential part of analytical applications in many fields including life science, medicine, veterinary medicine and biotechnology. Peculiarities of these measurements are largely determined by the uniqueness of quantity and analyte definitions. Quantitative PCR, applied for routine nucleic acids measurements, is a relative method demanding external calibrators with quantity values traceable to corresponding reference materials. Direct nucleic acid measurements became possible after introduction of the digital PCR (dPCR) method. Ensuring accurate, comparable and traceable to SI nucleic acids measurements is the focus of Nucleic Acid Analysis Working Group of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology. A number of pilot and key comparisons carried out by Working Group have shown that application of dPCR allows participating National Metrological Institutes to obtain comparable results of measurements of the sequence copy number concentrations and copy number ratios.

Fe- and SiFe-pillared clays from a mineralogical waste as adsorbents of ciprofloxacin from water

Considering the problem of the massive use of pharmaceuticals that find their way to the watercourses, pillared clays obtained from mineral clays have a great potential for their application in the removal of these pollutants by adsorption. In this work, Fe and SiFe-pillared clays were obtained from a mineral-industry waste, characterized and their removal capacity for ciprofloxacin (CPX) from aqueous media was evaluated. The Fe- and SiFe-pillared clay precursors were dried by two methods: freeze-drying and stove-drying. The influence of drying method on the structure and adsorptive properties of the pillared materials were studied. The pillared clays characterization showed higher hydrophobicity, sedimentation capacity, and porosity than the raw material. The adsorbed quantity values of CPX were comparable for all materials. The adsorption isotherm fits suggested the presence of heterogeneous adsorption sites for the pillared clays whereas the raw material shows homogeneous adsorption sites. The results showed that the drying method had a greater influence on Fe-PILC than on SiFe-PILC. In particular, the quantity of adsorbed CPX was constant at different pH values for freeze-drying Fe-PILC and the adsorption kinetic was faster than the other adsorbents at basic pH values. The analysis of the CPX-adsorbent adsorption complexes allowed to propose the formation of a mononuclear bidentate complex at pH 10.

Trade Competitiveness and Trend Pattern of Plantation Crop Exports in India

The foremost focus of this study is to scan the export performance of plantation sector in India for the years 1987-2019 using the CGAR, Cuddy-Della Valle instability index and index number. The analysis mainly draws conclusion on the selected major plantation crop tea, coffee, and cocoa. The analysis of growth trends of plantation crop exports during the overall period registered positive growth rate for export quantity and export unit value. The high growth rates of cocoa products together with high instability indices in the export revealed the prospects for Indian plantation sector in the global market during the post liberalization period. Incase of tea and coffee showed annual growth rate at minimum and instability indicating low to medium range during the overall period. While the trend analysis with the help of index number showed fluctuations in export quantity and export value throughout the study period which may be due to changing policies and its execution at different periods of time. The result indicated that India must give much effort to increase the export share of plantation crop and other value-added plantation products like green tea, toasted coffee grain, cocoa paste etc. to augment the foreign earnings.

Impact of Washing Processes on RNA Quantity and Quality in Patient-Derived Colorectal Cancer Tissues.

Background: Colorectal cancer (CRC) is a common and lethal cancer worldwide. Extraction of high-quality RNA from CRC samples plays a key role in scientific research and translational medicine. Specimen collection and washing methods that do not compromise RNA quality or quantity are needed to ensure high quality specimens for gene expression analysis and other RNA-based downstream applications. We investigated the effect of tissue specimen collection and different preparation processes on the quality and quantity of RNA extracted from surgical CRC tissues. Materials and Methods: After surgical resection, tissues were harvested and prepared with various washing processes in a room adjacent to the operating room. One hundred fourteen tissues from 36 CRC patients were separately washed in either cold phosphate-buffered saline reagent (n = 34) or Dulbecco's modified Eagle's medium (DMEM; n = 34) for 2-3 minutes until the stool was removed, and unwashed specimens served as controls (n = 34). Six tissue specimens were washed and immersed in DMEM for up to 1 hour at 4°C. Before RNA extraction, all specimens were kept in the stabilizing reagent for 3 months at -80°C. RNA was extracted, and the concentration per milligram of tissue was measured. RNA quality was assessed using the RNA integrity number (RIN) value. Results: Different washing processes did not result in significant differences in RNA quantity or RIN values. In the six tissues that were washed and immersed in DMEM for 1 hour, RIN values significantly decreased. The quality of the extracted RNA from most specimens was excellent with the average RIN greater than 7. Conclusions: RNA is stable in specimens washed in different processes for short periods, but RIN values may decrease with prolonged wash times.

The Estimation of Lipid Peroxidation and Osmotic Fragility of Human Red Blood Cell Induced by Pesticides Residues Detected in Some Vegetables Crops

Background: Many studies have reported the contamination by pesticides in a variety of matrices, such as food, water and soil, which despite their use, health risk of pesticides residues on food and in drinking water for the general population has been raised. The aim of this study is to quantify the pesticides residues of Abamectin and Imidacloprid in some vegetable samples; to study the in vitro effects of the both pesticides on the lipid peroxidation and hemolytic activity and finally, based on the mathematical models we estimate the values equivalent to the concentrations of pesticide residues detected in the vegetable samples. Methods: The extraction of pesticide residues from vegetable samples we use the FaPEx kits. Agilent Technologies 1260 infinity high performance liquid chromatography having UV/visible detector was used for the identification and quantification of pesticides residues. The results of this study proved the presence of pesticide residues in vegetable tested with higher values comparing with their corresponding MRLs. Result: The mean of the quantity of Abamectin detected in the vegetables samples ranged from 1.93 to 4.11 mg/kg for the green pepper (Capsicum annuum spp) and courgette (Cucurbita pepo), respectively. In addition, the Imidacloprid is just detected in the cucumber (Cucumis sativus) samples and the mean value of quantity is 24.09 mg/kg and corresponding MRL is 0.05 mg/kg. The in vitro study of the effects of the both pesticides on lipid peroxidation and hemolytic activity demonstrate significant effects of the different concentrations of the both pesticides on the both activities. The estimation by mathematical models of malondialdehyde quantity and hemolytic activity equivalent to the concentrations of the pesticides residues detected in vegetables samples proved the non-toxicity effects of these residues.

Exploring and Characterizing Patient Multibehavior Engagement Trails and Patient Behavior Preference Patterns in Pathway-Based mHealth Hypertension Self-Management: Analysis of Use Data.

BackgroundHypertension is a long-term medical condition. Mobile health (mHealth) services can help out-of-hospital patients to self-manage. However, not all management is effective, possibly because the behavior mechanism and behavior preferences of patients with various characteristics in hypertension management were unclear.ObjectiveThe purpose of this study was to (1) explore patient multibehavior engagement trails in the pathway-based hypertension self-management, (2) discover patient behavior preference patterns, and (3) identify the characteristics of patients with different behavior preferences.MethodsThis study included 863 hypertensive patients who generated 295,855 use records in the mHealth app from December 28, 2016, to July 2, 2020. Markov chain was used to infer the patient multibehavior engagement trails, which contained the type, quantity, time spent, sequence, and transition probability value (TP value) of patient behavior. K-means algorithm was used to group patients by the normalized behavior preference features: the number of behavioral states that a patient performed in each trail. The pages in the app represented the behavior states. Chi-square tests, Z-test, analyses of variance, and Bonferroni multiple comparisons were conducted to characterize the patient behavior preference patterns.ResultsMarkov chain analysis revealed 3 types of behavior transition (1-way transition, cycle transition, and self-transition) and 4 trails of patient multibehavior engagement. In perform task trail (PT-T), patients preferred to start self-management from the states of task blood pressure (BP), task drug, and task weight (TP value 0.29, 0.18, and 0.20, respectively), and spent more time on the task food state (35.87 s). Some patients entered the states of task BP and task drug (TP value 0.20, 0.25) from the reminder item state. In the result-oriented trail (RO-T), patients spent more energy on the ranking state (19.66 s) compared to the health report state (13.25 s). In the knowledge learning trail (KL-T), there was a high probability of cycle transition (TP value 0.47, 0.31) between the states of knowledge list and knowledge content. In the support acquisition trail (SA-T), there was a high probability of self-transition in the questionnaire (TP value 0.29) state. Cluster analysis discovered 3 patient behavior preference patterns: PT-T cluster, PT-T and KL-T cluster, and PT-T and SA-T cluster. There were statistically significant associations between the behavior preference pattern and gender, education level, and BP.ConclusionsThis study identified the dynamic, longitudinal, and multidimensional characteristics of patient behavior. Patients preferred to focus on BP, medications, and weight conditions and paid attention to BP and medications using reminders. The diet management and questionnaires were complicated and difficult to implement and record. Competitive methods such as ranking were more likely to attract patients to pay attention to their own self-management states. Female patients with lower education level and poorly controlled BP were more likely to be highly involved in hypertension health education.

A Feature Extraction Method for Non-intrusive Load Identification

When some household appliances are running, the electrical quantities such as active power and reactive power will change slowly for a long time, which will affect the feature extraction of event-based non-intrusive load identification, resulting in low accuracy of load identification results. In view of this situation, a feature extraction method is proposed. Its core idea is that there is a certain law in the change of active power and reactive power in a very short time, and the curve can be fitted to speculate the values of these electrical quantities in the next time, so as to eliminate the influence. Based on this, a feature extraction method applied to non-intrusive load identification is realized. The test results show that this method can effectively improve the accuracy of non-intrusive load identification feature extraction data, and has good application value.