Improving the integration of piece wise linear representation and weighted support vector machine for stock trading signal prediction

The integrated piecewise linear representation (PLR) and weighted support vector machine (PLR-WSVM) has shown success in the prediction of stock trading signals. Meanwhile drawbacks of PLR-WSVM exist particularly in a real world setting. For example, the profitability using PLR-WSVM is unstable, it is not reasonable to specify same threshold value for all stocks in PLR, and critical errors in trading signals may significantly reduce the profit. In this paper, we conduct a set of improvements to PLR-WSVM. First, most of absolute technical indicators in input variables are substituted with relative indicators since the relative indicators are generally more helpful in predicting trading signals. Second, a four-class prediction problem is converted into a two-class problem in which one class is a turning point (TP) and the other is an ordinary point. And prior domain knowledge is exploited to identify either buying or selling signals from TPs. Thirdly, a delay-one-day strategy (DODS) is proposed to further correct the predicted trading signals. DODS reduces the critical errors occurring to PLR-WSVM. Finally, a procedure for selecting a threshold in PLR is provided. The threshold is automatically selected by a given percentage of TPs in a training set. The percentage of TPs is easier to understand by investor compared with the threshold. We conduct experimental study over 20 stocks, and the results confirm the expected performance of the improved PLR-WSVM. More importantly, the improved PLR-WSVM provides steady profits in average over the stocks of interest with accepted retracements.     

COSINE软件包中子动力学程序KIND的点堆动力学模块设计

围绕实现点堆动力学程序工程化设计的问题，简介了COSINE软件包的点堆动力学计算模块。关于点堆算法的选取，本文对比了显式方法和去刚性算法计算各种典型瞬态问题的结果。结果表明，上述两种算法能充分满足设计可靠性的要求。关于反应性模型的设计，本文简介了全面覆盖各种反应性引入形式和反馈形式的设计思想。此外，还简介了本模块内置的热工模型。本文点堆动力学模块的设计具有良好的可靠性和灵活性。     

宽厚板工程厂房柱肩梁节点设计

介绍了宽厚板工程主轧跨42m柱距、450t位吊车厂房柱肩梁节点计算模型，节点截面设计形式，节点构造及其焊缝形式等，为大柱距、大吨位吊车厂房柱肩梁节点设计提供了参考。     

Enhanced control strategies for a hybrid battery/photovoltaic system using FGS-PID in grid-connected mode

This paper suggests improved control strategies using Fuzzy Gain Scheduling of Proportional-Integral-Derivative (FGS-PID) controller for a hybrid Photovoltaic (PV) and Battery Energy Storage (BES) system under different weather conditions. The proposed scheme is implemented using a two-level control system structure, combining the benefits of the PID as well as the fuzzy logic controller (FLC) for maximum power point tracking (MPPT). Ziegler-Nichols tuning method is also employed to select the initial values of PID gains. Within the period of steady-states and transients, FGS-PID adopts the gains to ensure the stability of the control scheme. It also damps out transient fluctuations and reduces settling time. Also, BES could be employed to provide a stable and reliable power from the output of PV sources to loads. It can enhance the performance of the entire power system during the grid-connected mode. The simulation results under Matlab/Simulink show that the suggested control strategies are robustness, fast transient response and proper steady-state performance in the grid-connected mode in comparison other presented methods.     

对城市道路平面交叉设计的探讨

从交通组织设计的角度出发，广泛参照国内外先进的理论与方法，结合平时工作积累的经验，从交叉口危险点、通行能力、渠化设计的角度进行分析探讨，并提出了一些思路，以供参考。     

This month ‘Technik ist alles’

The objective of this prospective cohort study was to evaluate if peak or cumulative musculoskeletal discomfort may predict future low-back, neck or shoulder pain among symptom-free workers. At baseline, discomfort per body region was rated on a 10-point scale six times during a working day. Questionnaires on pain were sent out three times during follow-up. Peak discomfort was defined as a discomfort level of 2 at least once during a day; cumulative discomfort was defined as the sum of discomfort during the day. Reference workers reported a rating of zero at each measurement. Peak discomfort was a predictor of low-back pain (relative risk (RR) 1.79), neck pain (RR 2.56), right or left shoulder pain (RR 1.91 and 1.90). Cumulative discomfort predicted neck pain (RR 2.35), right or left shoulder pain (RR 2.45 and 1.64). These results suggest that both peak and cumulative discomfort could predict future musculoskeletal pain.     

变工况条件下Bang-Bang控制与常规PID控制的集成设计与分析

将Bang-Bang控制与常规PID控制集成,研究了一种适用于大范围工况变化的变工况控制方法。对于非线性二阶系统,采用相轨迹法求解Bang-Bang控制的一次最优切换点;通过设置切换动作的最短响应时间来计算变工况控制的启动阈值。实例仿真结果表明:以变工况控制作为补充的集成控制方案,对全范围的工况变化具有良好的控制效果。     

一种新型泄油口外置式溢流阀组的研究

为了提高先导压力稳定性,针对溢流阀组原理及问题进行分析,并研究了一种新型的泄油口外置式溢流阀组结构。通过测试结果对比可知,该结构溢流阀组显著提高了系统使用性能及稳定性,并降低了能量损失。