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Both low temperature and light energy are important reasons for the decline in cucumber yield in winter of east and north China, therefore optimal utilization of light energy is critical for raising cucumber yield. In this study, Three-Dimensional (3D) cucumber canopy models were used to quantify the effects of weak light on dry matter production. Three 3D cucumber canopies were reconstructed with 20, 25, 30 leaves per plant respectively by using parametric modeling method. Light interception in these three 3D canopies from 8:00 to 15:00 on 4 Nov, 2015 was simulated by using the Radiosity-Graphic combined Model (RGM) with an hourly time step. CO2 assimilation per unit area was calculated using the FvCB photosynthetic model. As a result, the effects of light intensity and CO2 concentration on the photosynthetic rate were considered. The leaf photosynthesis simulation result showed that during the daytime in winter, the limiting factor affecting the photosynthesis rate in winter was light intensity. Especially in the morning, the CO2 concentration in the greenhouse was significantly higher than other moments. Increasing the light intensity or canopy light interception at this time should be very beneficial to the increase in yield production. It could be concluded that 25-leaf canopy was a more suitable canopy structure to autumn and winter canopy photosynthetic yields, through the comparative analysis of photosynthetic characteristics in these three virtual 3D canopies. This study also provides an important management basis for the optimal use of light in the greenhouse in winter of east China.

In the east of China, low temperature and light energy in winter are the main factors for the decline in cucumber yield, as well as in greenhouses without supplementary light. Optimal utilization of light energy is critical to increase cucumber yield. In this study, experimental measurements were conducted in two scenarios, April to May (Apr-May) and November to December (Nov-Dec) 2015, respectively, to analyze leaf development, dry matter accumulation, and yield of cultivated cucumber. Statistical analysis showed that leaves grew in Nov-Dec had larger leaf area and lower dry matter than leaves grew in Apr-May. This revealed that the dry matter accumulation rate per unit area was lower in winter. To be precise, the yield 0.174 kg/m2 per day in Nov-Dec was 35.3% lower than the yield in Apr-May. Environmental monitoring data showed that there was no significant difference in the average temperature between two scenarios, but the light intensity in Nov-Dec was only 2/3 of that in Apr-May. Three-dimensional (3D) cucumber canopy models were used in this study to quantify the effects of weak light on dry matter production in Nov-Dec. Three 3D canopies of cucumber were reconstructed with 20, 25, and 30 leaves per plant, respectively, by using a parametric modeling method. Light interception of three canopies from 8:00 to 15:00 on 4 November 2015 was simulated by using the radiosity-graphic combined model (RGM) with an hourly time step. CO2 assimilation per unit area was calculated using the FvCB photosynthetic model. As a result, the effects of light intensity and CO2 concentration on the photosynthetic rate were considered. The leaf photosynthesis simulation result showed that during the daytime in winter, the RuBP regeneration-limited assimilation Aj was always less than the Rubisco-limited assimilation Ac. This means that the limiting factor affecting the photosynthesis rate in winter was rather light intensity. As the CO2 concentration in the greenhouse was utmost in the morning, increasing the light intensity and therefrom increasing the canopy light interception at this time will be highly beneficial to increase the yield production. Through a comparative analysis of photosynthetic characteristics in these three virtual 3D canopies, the 25-leaf canopy was the best-performed canopy structure in photosynthetic production in winter. This study provides an insight into the light deficiency for yield production in winter and a solution to make optimal use of light in the greenhouse.

In order to withstand and recovery from multi-faults in elastic optical networks, we propose a novel multi-fault localization mechanism based on ant colony optimization and mixed line-rates. Multi-faults localization has been proved to be a NP-complete problem in wavelength switched optical networks, and all existing multi-faults localization algorithms require time that is super polynomial in the input size. Furthermore, multi-faults localization in elastic optical networks gets new features that the affected high-bit-rate services will play a greater role than the affected low-bit-rate services. In order to handle the mixed line-rates, we introduce the dependency metric which is used to describe dependency between alarms and likely causes. We establish the linear programming model for multi-faults localization and propose an objective function while considering the mixed line-rates. We implement the ant colony optimization based multi-faults localization mechanism on the stateful PCE-based multi-domain elastic optical networks test bed. The numerical results show that ant colony optimization based multi-faults localization mechanism has low flooding time and alarm packets, high success rate compared with the existing localization algorithms. We choose the best configuration of ant colony optimization based multi-faults localization by adjusting the parameters.

We consider the following inverse eigenvalue problem: to construct a special kind of matrix (real symmetric doubly arrow matrix) from the minimal and maximal eigenvalues of all its leading principal submatrices. The necessary and sufficient condition for the solvability of the problem is derived. Our results are constructive and they generate algorithmic procedures to construct such matrices.

A real symmetric unipotent matrix P is said to be n×n generalized reflection matrix. A real matrix A is said to be a generalized reflexive matrix with respect to generalized reflection matrix dual (P, Q) if A = PAQ. This paper involves related inverse eigenvalue problems of generalized reflexive matrices and their optimal approximation. Necessary and sufficient conditions for the solvability of the problem are derived, the general expression of the solution is given. The optimal approximate solution is also provided.