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The leaf area index (LAI) is an important growth indicator used to assess the health status and growth of citrus trees. Although LAI estimation based on unmanned aerial vehicle (UAV) platforms has been widely used for field crops, mainly focusing on food crops, less research has been reported on the application to fruit trees, especially citrus trees. In addition, most studies have used single-modal data for modeling, but some studies have shown that multi-modal data can be effective in improving experimental results. This study utilizes data collected from a UAV platform, including RGB images and point cloud data, to construct single-modal regression models named VoVNet (using RGB data) and PCNet (using point cloud data), as well as a multi-modal regression model called VPNet (using both RGB data and point cloud data). The LAI of citrus trees was estimated using deep neural networks, and the results of two experimental hyperparameters (loss function and learning rate) were compared under different parameters. The results of the study showed that VoVNet had Mean Squared Error (MSE), Mean Absolute Error (MAE), and R-Squared (R2) of 0.129, 0.028, and 0.647, respectively. In comparison, PCNet decreased by 0.051 and 0.014 to 0.078 and 0.014 for MAE and MSE, respectively, while R2 increased by 0.168 to 0.815. VPNet decreased by 0% and 42.9% relative to PCNet in terms of MAE and MSE to 0.078 and 0.008, respectively, while R2 increased by 5.6% to 0.861. In addition, the use of loss function L1 gave better results than L2, while a lower learning rate gave better results. It is concluded that the fusion of RGB data and point cloud data collected by the UAV platform for LAI estimation is capable of monitoring citrus trees' growth process, which can help farmers to track the growth condition of citrus trees and improve the efficiency and quality of orchard management. [ABSTRACT FROM AUTHOR]

This paper presents a general expression for the marginal distributions of the ordered eigenvalues of certain important random matrices. The expression, given in terms of matrix determinants, is compacter in representation and more efficient in computational complexity than existing results in the literature. As an illustrative application of the new result, we then analyze the performance of the multiple-input multiple-output singular value decomposition system. Analytical expressions for the average symbol error rate and the outage probability are derived, assuming the general double-scattering fading condition.

Based on the analysis of the internal control theory of Listed Companies in China and the United States, it is found that there are some differences in the definition, objectives and elements of internal control between China and the United States. The analysis shows that the internal control of Listed Companies in China is generally effective from 2013 to 2017, but it is decreasing year by year. Comparing the operation of Chinese and American listed companies in 2017, it is found that there are still significant differences in performance and internal control early warning system of different industries. The empirical results show that corporate governance level, marketization, information disclosure, internal control evaluation and weak audit links are the main reasons for the performance differences between Chinese and American listed companies. Therefore, some reasonable suggestions are put forward to improve the corporate governance mechanism and internal control efficiency. [ABSTRACT FROM AUTHOR]

It is a promising way to successfully operate the fifth generation (5G) system with Internet of Things (IoT) in potential mmWave spectrum bands. This paper investigates the intelligent co-channel coexistence between the 5G IoT system and the fixed-satellite service (FSS) system at 40 GHz. The key issue, as identified, is the accurate estimation of interference based on mmWave propagation characteristics. Our simulation results reveal that interference from the 5G IoT system into the FSS ground stations can be kept below the protection threshold by considering different deployment parameters, such as antenna patterns, height of Earth station (ES), and separation distance. [ABSTRACT FROM AUTHOR]

Natural products derived from fruits have multiple antitumor potential. However, very few have been developed for clinical therapy, due to the limited efficiency or insufficient study of their mechanism. Since lung cancer is the most common cancer in the world, there is still need to explore novel compounds but their molecular mechanisms remain elusive. In this study, a new compound Final-2 was synthesized. Final-2 exhibited antitumor activity in A549 cells by promoting apoptosis and blocking autophagy. Moreover, Final-2 significantly induced G 0 /G 1 cycle arrest and inhibited cell malignancy. Intracellular molecular targets investigation showed that Final-2 inhibited the Gluts, which resulted in downregulation of glucose metabolism and the oncogene c-Myc and Kras expression in vitro. However, according the autophagy inhibitor CQ and Kras inhibitors test, low concentration of Final-2 showed some controversial effects. In A549 xenograft mice model, 10 mg/kg and 20 mg/kg of Final-2 showed no and partial tumor inhibition, respectively. Moreover, a high dose of Final-2 induced serious liver necrosis. Therefore, the results indicated that even though Final-2 was efficient in suppressing the cancer cell growth in vitro, it failed to inhibit tumors in vivo and showed significant liver toxicity, which was its limitation as a potential antitumor drug. [ABSTRACT FROM AUTHOR]

In this paper, the buffer-constrained throughput performance of a multi-user wireless-powered communication (WPC) system is investigated, where energy harvesting follows a non-linear model. The investigation focuses on the buffer overflow performance of sending data in the downlink (DL) from the access point (AP) node to each user equipment (UE) node and that in the uplink from each UE node to the AP node, based on which the throughput performance on both directions when a buffer constraint is enforced is studied. Specifically, the buffer overflow probability at each node is analyzed, based on which the buffer-constrained throughput is studied. In addition, to ensure the throughput performance under the buffer constraint, the DL transmission power allocation policy and the required energy storage capacity at each UE are investigated. Also, the optimal channel time allocation policy is studied with the objective of maximizing the minimum buffer-constrained throughput guaranteed to each UE at the same time. To this aim, an optimization problem is first formulated and then a dichotomy-based time allocation algorithm combined with a one-dimensional search is proposed to solve this problem. The analysis and results, explicitly relating the throughput to the buffer constraint in addition to WPC characteristics, shed new light on the design and performance analysis of WPC systems. [ABSTRACT FROM AUTHOR]

The switching scheme between base band units (BBUs) and remote radio heads (RRHs) is a key point in a cloud radio access network (C-RAN). Fast BBU-RRH switching schemes will play crucial roles in future flexible C-RAN systems. In this letter, an evaluation model is proposed to analyze the performance of fast switching schemes. Based on the model, we also propose an evaluation methodology through jointly taking backlogs, idle resources, and switching costs into account. The evaluation methodology provides guidance on future design for fast switching schemes. Finally, the effectiveness of the proposed methodology is validated by simulation results. [ABSTRACT FROM PUBLISHER]

Licensed-assisted access (LAA) to unlicensed spectrum has drawn the worldwide attention from academia and industry since its emergence at the Third Generation Partnership Project in 2015. As a key technology for Long Term Evolution unlicensed spectrum deployment, LAA goes far toward solving the coexistence problems in the 5-GHz unlicensed bands. However, owing to unpredictable interference from unlicensed-band opponent systems, for example, WiFi, LAA uplink transmission may suffer from serious inefficiency in scheduling-based radio access. To tackle such an issue, this letter proposes a dynamic uplink radio access selection scheme between scheduling and random access for LAA uplink transmission. Next, in order to exploit optimum performance, an optimization game of the uplink radio access selection is formulated. Last but not least, the optimum solution of the game is proved to exist by potential game theory, laying instructive foundations for LAA uplink standardizations. [ABSTRACT FROM PUBLISHER]