基于NWP和改进神经网络的短啦风电功率预测研究

风电场功率预测对电力系统稳定运行起着决定性作用。首先对传统BP神经网络进行改进,以某一风电场获取的2月1日-10日的天气预报（NWP）数据和功率数据作为改进后BP神经网络的训练数据,对神经网络进行训练;其次以2月11号3小时的数值天气预报数据作为改进后BP神经网络的输入数据,对未来3小时的输出功率进行预测。预测过程和结果显示,改进后的BP神经网络在满足低预测误差的同时,能够提高BP神经网络的稳定性和收敛速度。     

大学生交友误区探析

朋友在一个人生命中是不可或缺的人物,真正的朋友可以在难过时分担忧伤,开心时分享快乐.本文主要阐述了当前大学生交友过程中容易形成的误区,并引导他们要走出交友的误区,交上真正的朋友.     

基于小型语料库的大学英语写作错误分析

小型语料库和大型语料库的结合能使教师从英语学习者的共性中找到适合本校英语学习者的具体特点。以语料库为手段对大学生不同学习阶段的英语作文中的错误进行分析,对于把握学习者在不同学习阶段中的写作错误的共性和规律有重要意义,从而进行针对教学。     

Named entity recognition in Turkish: A comparative study with detailed error analysis

Named entity recognition aims to detect pre-determined entity types in unstructured text. There is a limited number of studies on this task for low-resource languages such as Turkish. We provide a comprehensive study for Turkish named entity recognition by comparing the performances of existing state-of-the-art models on the datasets with varying domains to understand their generalization capability and further analyze why such models fail or succeed in this task. Our experimental results, supported by statistical tests, show that the highest weighted F1 scores are obtained by Transformer-based language models, varying from 80.8% in tweets to 96.1% in news articles. We find that Transformer-based language models are more robust to entity types with a small sample size and longer named entities compared to traditional models, yet all models have poor performance for longer named entities in social media. Moreover, when we shuffle 80% of words in a sentence to imitate flexible word order in Turkish, we observe more performance deterioration, 12% in well-written texts, compared to 7% in noisy text.     

一种基于单片机的智能电子天平系统

介绍了一种基于80C31处理器的智能电子天平系统的工作原理，包括系统的硬件原理及软件流程框图，并较系统地进行了误差分析。本系统应用了电磁力反馈平衡零位法原理，采用单片微处理器进行实时控制和数据处理，实现了天平的电子化、数字化、智能化。     

PH-spline approximation for Bézier curve and rendering offset

In this paper, a G¹, C¹, C² PH-spline is employed as an approximation for a give Bézier curve within error bound and further renders offset which can be regarded as an approximate offset to the Bézier curve. The errors between PH-spline and the Bézier curve, the offset to PH-spline and the offset to the given Bézier curve are also estimated. A new algorithm for constructing offset to the Bézier curve is proposed. Project supported by the National Natural Foundation of China (No. 60073023) and the National Basic Research Program (973) of China (No. 2002CB312101)     

On constructing symmetrical reversible variable-length codes independent of the Huffman code

Reversible variable length codes (RVLCs) have received much attention due to their excellent error resilient capabilities. In this paper, a novel construction algorithm for symmetrical RVLC is proposed which is independent of the Huffman code. The proposed algorithm's codeword assignment is only based on symbol occurrence probability. It has many advantages over symmetrical construction algorithms available for easy realization and better code performance. In addition, the proposed algorithm simplifies the codeword selection mechanism dramatically.     

线性模型中相关附加信息全部损失的条件(英文)

通过讨论回归系数的混合估计和Bayes估计的相关附加信息全部损失的条件,本文给出了线性模型中选择相关附加样本应遵守的一个原则,并研究了两个应用问题。     

RTP-based broadcast streaming of high definition H.264/AVC video: an error robustness evaluation

In this work, we present an evaluation of the performance and error robustness of RTP-based broadcast streaming of high-quality high-definition (HD) H.264/AVC video. Using a fully controlled IP test bed (Hillestad et al., 2005), we broadcast high-definition video over RTP/UDP, and use an IP network emulator to introduce a varying amount of randomly distributed packet loss. A high-performance network interface monitoring card is used to capture the video packets into a trace file. Purpose-built software parses the trace file, analyzes the RTP stream and assembles the correctly received NAL units into an H.264/AVC Annex B byte stream file, which is subsequently decoded by JVT JM 10.1 reference software. The proposed measurement setup is a novel, practical and intuitive approach to perform error resilience testing of real-world H.264/AVC broadcast applications. Through a series of experiments, we evaluate some of the error resilience features of the H.264/AVC standard, and see how they perform at packet loss rates from 0.01 % to 5%. The results confirmed that an appropriate slice partitioning scheme is essential to have a graceful degradation in received quality in the case of packet loss. While flexible macroblock ordering reduces the compression efficiency about 1 dB for our test material, reconstructed video quality is improved for loss rates above 0.25%.     

一类非线性离散Bihari-Type型不等式解的估计

本文建立了一类具有n项非线性离散Bihari-Type型不等式解的估计,并用实例给出了解的估计.