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Spectroscopic Evaluation of Effects of Heat Treatments on the Structures and Emulsifying Properties of Caseins
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作者 ZHANG Hao WANG Peng-jie +4 位作者 LEI Xin-gen YANG Hong-ju ZHANG Lu-da REN Fa-zheng ZHENG Li-min 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2013年第5期1275-1280,共6页
The effects of heat treatment(heating temperature and pH) on the structures and emulsifying properties of caseins were systematically studied by spectroscopy.Heat treatment from 60to 100℃resulted in an increase in th... The effects of heat treatment(heating temperature and pH) on the structures and emulsifying properties of caseins were systematically studied by spectroscopy.Heat treatment from 60to 100℃resulted in an increase in their fluorescence intensity,hydrodynamic diameter,turbidity and emulsifying activity index,but decreased the size polydispersity of caseins.In the pH range of 5.5to 7.0,the fluorescence intensity,hydrodynamic diameter,turbidity and emulsifying properties decreased with increased heating pH,but the size polydispersity of caseins increased with increased pH.The relationship between the surface fluorescence intensity and emulsifying activity was also investigated,revealing a correlation coefficient of 0.90.These results suggested that heat treatment could be used to modify the structures and emulsifying properties of caseins by appropriately selecting heating conditions. 展开更多
关键词 CASEINS Heat treatment STRUCTURES Emulsifying properties Fluorescence spectrometry Dynamic light scattering TURBIDITY
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Fishing Effort Estimation of Trawlers Based on Vessel Monitoring System Data
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作者 LI Dan LU Feng +8 位作者 XU Shuo WANG Yu XUE Muhan NI Hanchen FANG Hui ZHANG Man MA Zhenhua CHEN Zuozhi XU Jian 《农业机械学报》 北大核心 2025年第2期523-532,共10页
Estimating trawler fishing effort plays a critical role in characterizing marine fisheries activities,quantifying the ecological impact of trawling,and refining regulatory frameworks and policies.Understanding trawler... Estimating trawler fishing effort plays a critical role in characterizing marine fisheries activities,quantifying the ecological impact of trawling,and refining regulatory frameworks and policies.Understanding trawler fishing inputs offers crucial scientific data to support the sustainable management of offshore fishery resources in China.An XGBoost algorithm was introduced and optimized through Harris Hawks Optimization(HHO),to develop a model for identifying trawler fishing behaviour.The model demonstrated exceptional performance,achieving accuracy,sensitivity,specificity,and the Matthews correlation coefficient of 0.9713,0.9806,0.9632,and 0.9425,respectively.Using this model to detect fishing activities,the fishing effort of trawlers from Shandong Province in the sea area between 119°E to 124°E and 32°N to 40°N in 2021 was quantified.A heatmap depicting fishing effort,generated with a spatial resolution of 1/8°,revealed that fishing activities were predominantly concentrated in two regions:121.1°E to 124°E,35.7°N to 38.7°N,and 119.8°E to 122.8°E,33.6°N to 35.4°N.This research can provide a foundation for quantitative evaluations of fishery resources,which can offer vital data to promote the sustainable development of marine capture fisheries. 展开更多
关键词 TRAWLER vessel position data machine learning fishing effort
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MPMS-SGH:Multi-parameter Multi-step Prediction Model for Solar Greenhouse
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作者 JI Ronghua WANG Wenxuan +2 位作者 AN Dong QI Shaotian LIU Jincun 《农业机械学报》 北大核心 2025年第7期265-278,共14页
Accurately predicting environmental parameters in solar greenhouses is crucial for achieving precise environmental control.In solar greenhouses,temperature,humidity,and light intensity are crucial environmental parame... Accurately predicting environmental parameters in solar greenhouses is crucial for achieving precise environmental control.In solar greenhouses,temperature,humidity,and light intensity are crucial environmental parameters.The monitoring platform collected data on the internal environment of the solar greenhouse for one year,including temperature,humidity,and light intensity.Additionally,meteorological data,comprising outdoor temperature,outdoor humidity,and outdoor light intensity,was gathered during the same time frame.The characteristics and interrelationships among these parameters were investigated by a thorough analysis.The analysis revealed that environmental parameters in solar greenhouses displayed characteristics such as temporal variability,non-linearity,and periodicity.These parameters exhibited complex coupling relationships.Notably,these characteristics and coupling relationships exhibited pronounced seasonal variations.The multi-parameter multi-step prediction model for solar greenhouse(MPMS-SGH)was introduced,aiming to accurately predict three key greenhouse environmental parameters,and the model had certain seasonal adaptability.MPMS-SGH was structured with multiple layers,including an input layer,a preprocessing layer,a feature extraction layer,and a prediction layer.The input layer was used to generate the original sequence matrix,which included indoor temperature,indoor humidity,indoor light intensity,as well as outdoor temperature and outdoor light intensity.Then the preprocessing layer normalized,decomposed,and positionally encoded the original sequence matrix.In the feature extraction layer,the time attention mechanism and frequency attention mechanism were used to extract features from the trend component and the seasonal component,respectively.Finally,the prediction layer used a multi-layer perceptron to perform multi-step prediction of indoor environmental parameters(i.e.temperature,humidity,and light intensity).The parameter selection experiment evaluated the predictive performance of MPMS-SGH on input and output sequences of different lengths.The results indicated that with a constant output sequence length,the prediction accuracy of MPMS-SGH was firstly increased and then decreased with the increase of input sequence length.Specifically,when the input sequence length was 100,MPMS-SGH had the highest prediction accuracy,with RMSE of 0.22℃,0.28%,and 250lx for temperature,humidity,and light intensity,respectively.When the length of the input sequence remained constant,as the length of the output sequence increased,the accuracy of the model in predicting the three environmental parameters was continuously decreased.When the length of the output sequence exceeded 45,the prediction accuracy of MPMS-SGH was significantly decreased.In order to achieve the best balance between model size and performance,the input sequence length of MPMS-SGH was set to be 100,while the output sequence length was set to be 35.To assess MPMS-SGH’s performance,comparative experiments with four prediction models were conducted:SVR,STL-SVR,LSTM,and STL-LSTM.The results demonstrated that MPMS-SGH surpassed all other models,achieving RMSE of 0.15℃for temperature,0.38%for humidity,and 260lx for light intensity.Additionally,sequence decomposition can contribute to enhancing MPMS-SGH’s prediction performance.To further evaluate MPMS-SGH’s capabilities,its prediction accuracy was tested across different seasons for greenhouse environmental parameters.MPMS-SGH had the highest accuracy in predicting indoor temperature and the lowest accuracy in predicting humidity.And the accuracy of MPMS-SGH in predicting environmental parameters of the solar greenhouse fluctuated with seasons.MPMS-SGH had the highest accuracy in predicting the temperature inside the greenhouse on sunny days in spring(R^(2)=0.91),the highest accuracy in predicting the humidity inside the greenhouse on sunny days in winter(R^(2)=0.83),and the highest accuracy in predicting the light intensity inside the greenhouse on cloudy days in autumm(R^(2)=0.89).MPMS-SGH had the lowest accuracy in predicting three environmental parameters in a sunny summer greenhouse. 展开更多
关键词 solar greenhouse environmental parameter time series multi-step prediction
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High-Precision Fish Pose Estimation Method Based on Improved HRNet
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作者 PENG Qiujun LI Weiran +1 位作者 LIU Yeqiang LI Zhenbo 《智慧农业(中英文)》 2025年第3期160-172,共13页
[Objective]Fish pose estimation(FPE)provides fish physiological information,facilitating health monitoring in aquaculture.It aids decision-making in areas such as fish behavior recognition.When fish are injured or def... [Objective]Fish pose estimation(FPE)provides fish physiological information,facilitating health monitoring in aquaculture.It aids decision-making in areas such as fish behavior recognition.When fish are injured or deficient,they often display abnormal behaviors and noticeable changes in the positioning of their body parts.Moreover,the unpredictable posture and orientation of fish during swimming,combined with the rapid swimming speed of fish,restrict the current scope of research in FPE.In this research,a FPE model named HPFPE is presented to capture the swimming posture of fish and accurately detect their key points.[Methods]On the one hand,this model incorporated the CBAM module into the HRNet framework.The attention module enhanced accuracy without adding computational complexity,while effectively capturing a broader range of contextual information.On the other hand,the model incorporated dilated convolution to increase the receptive field,allowing it to capture more spatial context.[Results and Discussions]Experiments showed that compared with the baseline method,the average precision(AP)of HPFPE based on different backbones and input sizes on the oplegnathus punctatus datasets had increased by 0.62,1.35,1.76,and 1.28 percent point,respectively,while the average recall(AR)had also increased by 0.85,1.50,1.40,and 1.00,respectively.Additionally,HPFPE outperformed other mainstream methods,including DeepPose,CPM,SCNet,and Lite-HRNet.Furthermore,when compared to other methods using the ornamental fish data,HPFPE achieved the highest AP and AR values of 52.96%,and 59.50%,respectively.[Conclusions]The proposed HPFPE can accurately estimate fish posture and assess their swimming patterns,serving as a valuable reference for applications such as fish behavior recognition. 展开更多
关键词 AQUACULTURE computer vision fish pose estimation key point attention mechanism
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Improved differential evolution algorithm for resource-constrained project scheduling problem 被引量:4
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作者 Lianghong Wu Yaonan Wang Shaowu Zhou 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第5期798-805,共8页
An improved differential evolution(IDE)algorithm that adopts a novel mutation strategy to speed up the convergence rate is introduced to solve the resource-constrained project scheduling problem(RCPSP)with the obj... An improved differential evolution(IDE)algorithm that adopts a novel mutation strategy to speed up the convergence rate is introduced to solve the resource-constrained project scheduling problem(RCPSP)with the objective of minimizing project duration Activities priorities for scheduling are represented by individual vectors and a senal scheme is utilized to transform the individual-represented priorities to a feasible schedule according to the precedence and resource constraints so as to be evaluated.To investigate the performance of the IDE-based approach for the RCPSP,it is compared against the meta-heuristic methods of hybrid genetic algorithm(HGA),particle swarm optimization(PSO) and several well selected heuristics.The results show that the proposed scheduling method is better than general heuristic rules and is able to obtain the same optimal result as the HGA and PSO approaches but more efficient than the two algorithms. 展开更多
关键词 differential evolution algorithm project soheduling resource constraint priority-based scheduling.
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Discrete-time Indefinite Stochastic LQ Optimal Control: Infinite Horizon Case 被引量:3
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作者 QI Jun-Jun ZHANG Wei-Hai 《自动化学报》 EI CSCD 北大核心 2009年第5期613-617,共5页
关键词 随机系统 LQ 浙近线 自动化
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线性奇异时滞系统的观测器设计 被引量:1
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作者 冯俊娥 张维海 程兆林 《自动化学报》 EI CSCD 北大核心 2005年第3期372-378,共7页
Two kinds of observers for linear singular time-delay systems, namely functional observers and full-order observers, are considered in this paper. For the former, observers with and without internal delay are consider... Two kinds of observers for linear singular time-delay systems, namely functional observers and full-order observers, are considered in this paper. For the former, observers with and without internal delay are considered. For the latter, observers without internal delay is given. The corresponding design steps for various observers, which are all normal linear time-delay systems, are presented. Numerical examples are given to illustrate the methods. 展开更多
关键词 奇异时滞系统 观测器 设计 线性
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