基于近邻估计的年径流预测动态 联系数回归模型

集对分析理论为处理确定、不确定系统提供了新的途径,根据集对分析理论建立起来的预测联系数回归模型可以明显改善回归模型的预测精度。对于预测因子结构具有的动态性,文中将利用近邻估计,通过计算各个预测因子的变异系数,来判断预测因子在某次预测中处于强势或者弱势,进而动态地选择预报功能大的强势因子,消除对预报起负面作用的弱势因子的作用,这样很好地体现了预测因子结构中具有的动态性。基于此建立了基于近邻估计的年径流预测动态联系数回归模型（NNE-DCNR）。结果说明：用NNE-DCNR去预测年径流量,预测精度比常用预测方法有显著提高,在水文水资源的预测中具有推广应用价值     

一类非线性分形插值曲面的构造与性质

讨论了二元连续函数振幅与变差的性质,并构造了一类非线性多参数迭代函数系;证明了在一定条件下吸引子的唯一性和分形插值曲面的存在性,利用连续函数变差的性质研究了所构造的分形插值曲面的维数,并给出了此类分形插值曲面计盒维数的计算公式.     

瓯江河口入海水沙通量的变化规律

根据瓯江流域圩仁水文站1950-2008年的实测流量资料和1956-1998年的实测输沙量资料,采用水文学和数理统计学方法,分析瓯江河口入海水、沙通量的变化规律及其相关性,并对人类活动的影响进行了探讨。研究结果表明:瓯江多年平均入海流量和悬沙通量分别为442m3/s、61.9kg/s;入海水、沙通量具有明显的年际和季节变化特征,沙通量的变幅要大于水通量;瓯江洪枯季流量、输沙量悬殊,洪峰暴涨暴落,是输水、输沙最集中时期;入海水、沙通量之间具有较好的峰、谷对应关系,但1975年特大洪水导致流域侵蚀模量发生较大变化;紧水滩、石塘水库的建成和运行,对瓯江入海径流起到了明显的调节作用,水沙通量年内分配趋于均匀化。     

Multiplicative noise removal combining a total variation regularizer and a nonconvex regularizer

A novel variational model for removing multiplicative noise is proposed in this paper. In the model, a novel regularization term is elaborately designed which is inherently equivalent to a combination of the classical total variation regularizer and a nonconvex regularizer. The proposed regularization term, on the one hand, can better remove the noise in homogeneous regions of a noisy image and, on the other hand, can preserve edge details of the image during the denoising process. In order to solve the model efficiently, we design an alternating iteration process in which two coupling minimization problems are solved. For each of the two minimization problems, the existence and uniqueness of their solutions are proved under some necessary assumptions. Numerical results are reported to demonstrate the effectiveness of the proposed regularization term for multiplicative noise removal.     

基于人工鱼群的交通诱导系统最优查询研究

与齐齐哈尔市公安交通警察支队交通控制中心合作开发,并以齐齐哈尔市路况为实际进行凋研,将改进的人工鱼群算法应用于交通路径诱导系统数据库优化查淘中,算法提高了最优路径查询的效率。对人工鱼群算法进行了改进,引入贝叶斯变异算子和十字交叉变异算子,避免了算法局部寻优能力差和收敛速度慢等弊端。仿真实验表明算法是正确有效性的。     

FISH ASSEMBLAGES RESPOND TO HABITAT AND HYDROLOGY IN THE WABASH RIVER,INDIANA

Detailed relationships between fish assemblages and habitat and hydrology variation are largely unknown for large rivers. We evaluated hydrology, habitat variation and fish assemblages at 28 sites on the Wabash River, Indiana, USA, during 2005–2008. We calculated hydrologic variation with the Indicators of Hydrologic Alteration software and tested for temporal hydrologic effects on habitat variation of substrate particle size, water depth and water velocity by reducing data into principal component axes that were tested for differences among years with ANOVAs. We then tested for effects of habitat and hydrology variation on fish assemblages with canonical correspondence analysis. These analyses showed significant relationships between hydrologic variation and local habitats, and hydrology and habitat variables had significant relationships with fish assemblage structure. Our Mantel tests resulted in significant concordance among hydrology, local habitat variation and fish assemblage structure, suggesting associations of these variables. These results supported strong connections for hydraulic control over habitat variation and subsequent effects on fish assemblages. Copyright © 2011 John Wiley & Sons, Ltd.     

ENVIRONMENTAL DETERMINANTS OF WATER QUALITY IN BOREAL RIVERS BASED ON PARTITIONING METHODS

Quantitative studies of the relationships between river water quality and environmental variables are needed to improve understanding of the impacts of natural and human factors on aquatic environments. However, multicollinearity between environmental variables can hinder the identification of key factors when water quality–environment relationship is studied using traditional regression methods. This study utilized two alternative statistical methods, variation and hierarchical partitioning, to address these difficulties in studies of river water quality. Using these methods, we explored the effects of catchment physiography, climate and land use variables on total phosphorus and nitrogen, pH, water colour and dissolved oxygen during the years 1995–2005 in 32 boreal rivers in Finland. Catchment physiography and land use explained most of the variation in water quality, especially in phosphorus, nitrogen and water colour data. The strong correlations (r_s > 0.8) between agricultural land use and phosphorus and nitrogen concentrations indicate that water quality is highly affected by agriculture in boreal regions. By determining the environmental drivers of different water quality variables, we can estimate the water quality of different catchments in response to environmental changes and identify areas that are sensitive to global changes. Our study shows that novel statistical methods integrated with geographic information system data and techniques provide deeper insights into water quality–environment relationships than traditional regression, and these should be considered when developing, for example, conservation planning for rivers. Copyright © 2011 John Wiley & Sons, Ltd.     

渭河上游河川径流演变特性分析

为了研究渭河上游径流演变特性,以林家村等5个水文站近50 a的实测径流序列为基础,采用Mann-Kendall趋势分析法(M-K法)和R/S法分析了径流演变趋势。结果表明：渭河上游径流年内分配在20世纪50年代较为集中,60~90年代相对均匀;径流年际变化较大;径流量总体呈下降趋势,且趋势性较为显著。研究成果为渭河流域水资源开发利用、调度管理和生态环境保护提供一定参考。     

A national cross-sectional study in the Danish wood and furniture industry on working postures and manual materials handling

Musculoskeletal disorders constitute a major problem in the wood and furniture industry and identification of risk factors is needed urgently. Therefore, exposures to different work tasks and variation in the job were recorded based on an observation survey in combination with an interview among 281 employees working in wood working and painting departments. A questionnaire survey confirmed high frequencies of symptoms from the musculoskeletal system: The one-year prevalence of symptoms from the low back was 42% and symptoms from the neck/shoulder was 40%. The exposure was evaluated based on: (1) classification of work tasks, (2) work cycle time, (3) manual materials handling, (4) working postures, and (5) variation in die job. Among the employees 47% performed feeding or clearing of machines, 35% performed wood working or painting materials, and 18% performed various other operations. Among the employees 20% had no variation in their job while 44% had little variation. Manual materials handling of 375 different burdens was observed, which most often occurred during feeding or clearing of machines. The weight of burdens lifted was 0·5-87·0 kg, where 2% had a weight of more than 50 kg. Among the lifting conditions 30% were evaluated as implying a risk of injury. An additional risk factor was the high total tonnage lifted per day, which was estimated to range from 132 kg to 58 800 kg. Working postures implied a risk of injury due to prolonged forward and lateral flexions of the neck, which was seen most frequently during wood working or painting materials. These data substantiate the finding that work tasks mainly during feeding or clearing of machines imply a risk of injury to the low back and a risk of injury to the neck and shoulder area mainly during wood working or painting materials. Optimal strategies for job redesign may be worked out by using these data in order to prevent occupational musculoskeletal disorders.     

Psychological impact of air velocity variations in a ventilated room

Two experiments investigated the psychological impact of two velocity conditions (constant low velocity (V1) and variations of low and high velocity (V2)) in two temperature conditions (Experiment 1: an air temperature increase from 21°C to 24°C; Experiment 2: an air temperature increase from 25°C to 27°C) in females and males, aged 16 to 18 years, under realistic classroom conditions during an exposure period of 80 min. It was predicted that the V2 room condition compared to the V1 room condition would be more beneficial for subjects' perceived room temperature and air quality, self-reported affect and cognitive performance. The results obtained showed no significant effects on cognitive performance. However and as predicted, in Experiment 1, the subjects in the V2 compared to those in the V1 room condition felt that the air temperature decreased (while it de facto increased) and reported a constant level of high activation. In Experiment 2, the subjects in the V2 room condition felt that the air temperature increased less and reported that their unactivated unpleasantness increased less and activated pleasantness decreased less than it did for subjects in the V1 room condition. All this indicates, as was suggested by Wigö et al. (2002 Wigö, H., Knez, I. and Sandberg, M. 2002. Effects of velocity variations in ventilated room on comfort, affect and cognitive performance. Proceedings of 9th International Conference on Indoor Air Quality and Climate, 4: 635–640.  [Google Scholar]), that a cooling effect, induced by air velocity variations, might be beneficial for subjects in a ventilated room and that their perceived pleasantness of the indoor climate could be met at a higher room temperature than otherwise.