Gibbs Ensembles for Nearly Compatible and Incompatible Conditional Models

The Gibbs sampler has been used exclusively for compatible conditionals that converge to a unique invariant joint distribution. However, conditional models are not always compatible. In this paper, a Gibbs sampling-based approach-using the Gibbs ensemble-is proposed for searching for a joint distribution that deviates least from a prescribed set of conditional distributions. The algorithm can be easily scalable, such that it can handle large data sets of high dimensionality. Using simulated data, we show that the proposed approach provides joint distributions that are less discrepant from the incompatible conditionals than those obtained by other methods discussed in the literature. The ensemble approach is also applied to a data set relating to geno-polymorphism and response to chemotherapy for patients with metastatic colorectal cancer.     

自动矿浆取样机的设计与应用

主要介绍了矿山化验中人工取样存在的问题和自动链式矿浆取样机的设计原理、结构以及应用情况。     

被动式氚取样器性能的实验研究

目前被动式氘取样器在国外取得了广泛的应用,它是基于气体分子扩散或渗透原理采集空气中氘化水蒸汽（HTO）样品的一种方法。本文对被动式氘取样的工作原理从理论上进行了分析,用水所模拟实验测定了液闪计数瓶顶盖孔板直径分别为Φ2－10mm的几种取样器的扩散系数和等效取样流量,并在现场进行了初步应用。     

建立分离器流出气体均流流场的模拟试验

采用维托辛斯基曲线收敛器，在油气分流器的气出口处建立的流流场，进行了建立了流器气出口外建立的均流流场，进行了建立流场的模拟试验。模拟试验装置主要是由分流罐，扩散器、稳定筒，整流器、测量试段等组成。试验结果表明，收敛器出口处圆管截面上的气速不均匀度最大不超过２％，基本达到建立均充场的目的。     

干冰升华式孔底冷冻取样器冷源保冷方法的试验研究

针对已研制的天然气水合物孔底冷冻取样器,为进一步提高取样器干冰冷源的保冷效果,提出干冰冷源双层保冷方法.通过试验研究,证明干冰冷源双层保冷方法可大幅度提高干冰在井内的保存时间,可以将此方法应用于取样器的设计.     

新型钟控取样器的研制

针对目前井下取样器使用过程中出现的问题,研制出了QYQ-B型新式井下钟控取样器.该取样器结构简单、维护保养方便、施工成功率高,从根本上解决了漏样、窜样等问题,减少了返工损失,缩短了试油周期.经过现场多次试验,取得了较好的效果.     

基于改进型Potts模型的图像分割

在分析Opera等人提出的能量更新算法的基础上,该文提出了改进算法。对图像预分割,将对像素的处理转换为对像素团的处理,从而加快了聚类的过程。改进了算法的采样方法,用Metropolis采样替代Gibbs采样。在成功分割静态图像的基础上,实现对视频图像序列的分割。实验结果表明该算法比原算法有更佳的分割效果,而且收敛速度比原算法快30-40倍。     

入炉煤采样机系统设备的改进

介绍了张家口发电厂一期入炉煤采样机设备的特点,根据设备运行现状和存在的问题,对该采样机系统设备进行了有效的改造,收到了良好的效果.     

AYX2-1型悬移质采样器在万家埠水文站的应用

为有效解决万家埠水文站长期存在的悬移质测验难题,对该站原有测验方式进行了优化。文章介绍了AYX2-1型悬移质采样器的工作原理及其在万家埠水文站的比测试验情况,通过对2019年以来高、中、低水位级试验数据的对比分析,采样器进口流速系数和采集样品的一致性符合规范要求;依据采样器的工作原理和万家埠水文站的悬移质日常测验方案,分别针对单、断沙以及特殊水情期间的采样构建了相应取样模型,提升了取样效率和精度,可操作性强。     

An improved Markov Chain Monte Carlo method for MIMO iterative detection and decoding

Recently, a new soft-in soft-out detection algorithm based on the Markov Chain Monte Carlo （MCMC） simulation technique for Multiple-Input Multiple-Output （MIMO） systems is proposed, which is shown to perform significantly better than their sphere decoding counterparts with relatively low complexity. However, the MCMC simulator is likely to get trapped in a fixed state when the channel SNR is high, thus lots of repetitive samples are observed and the accuracy of A Posteriori Probability （APP） estimation deteriorates. To solve this problem, an improved version of MCMC simulator, named forced-dispersed MCMC algorithm is proposed. Based on the a posteriori variance of each bit, the Gibbs sampler is monitored. Once the trapped state is detected, the sample is dispersed intentionally according to the a posteriori variance. Extensive simulation shows that, compared with the existing solution, the proposed algorithm enables the markov chain to travel more states, which ensures a near-optimal performance.