消费的信息成本和信息收益

由于消费者和供应商之间存在着信息不对称,消费者的消费行为就存在着信息成本问题,文章力图从商品的同质和异质两个方面去分析消费交易活动的信息成本和信息收益,并进一步提出供应商降低信息不对称程度的措施。     

八数码问题的搜索算法比较

搜索策略是人工智能研究的主攻方向之一,采用不同的搜索策略在求解问题的过程中也会存在差异.通过对于八数码的搜索求解分析,采用盲目搜索中的广度优先搜索算法和启发式搜索中的A*算法进行实现,将广度优先搜索算法与A*算法进行比较,从而评价这两种搜索算法的优劣性.     

Error analysis of non-spherical raindrops on precipitation measurement

Radar cross section (RCS) of non-spherical raindrops is calculated by using the software CST based on finite integral method and compared with RCS of spherical raindrops. The revised factor of non-spherical raindrops is obtained. The radar reflectivity with precipitation change of four distribution models of M-P, Gamma, JD and JT combining the revised factor is gotten using trapezoidal integration. When the influence of non-spherical raindrops is considered, the accuracy of precipitation measurement of four distribution models can be separately improved 8.77%, 8.47%, 10.53% and 8.04% in the case of rain intensity is 100 mm/h.     

Searching high gray scale FPD scanning matrix based on PSO

With the increase of gray scale and flat panel display (FPD) size, subspace bitwise scanning strategy can be replaced traditional scanning method to cut down frame frequency. However, the direct searching strategy (DSS) becomes unfeasible to obtain corresponding high gray scale scanning matrix. Thus, particle swarm optimization (PSO) is introduced to accelerate searching for high gray scale weights scanning matrix (WSM) with its parallelism and global optimization feature. Finally a WSM of 256 gray scales is found out successfully with Matlab, which both gray linearity and scanning efficiency are satisfied.     

“教育模式”的华丽外衣

当下,基础教育界所诮“模式”不断涌现。小少地方教育部门和学校都举着实施新课程的大鹿,创立种种“模式”,似乎有了“模式”就跟上新课稗市奏了,就有特色亮点了,也就口,以提高知名度了。在百度搜索“杜郎口模式”     

为女巫欢呼

三、飞翔的女巫"这两天把附近几个城市都玩遍了。"小璇边开着车边说,"今天要找一个新鲜一点儿的地方。""去炫一点儿的城市,去香港吧。""还是去美国好。""美国的领空不会让咱们飞行的,他们有雷达。"蓝脸和猫头鹰争执不休的时候,小璇开着车正在城市里穿梭,     

优化问题的新步长法则

The step-size procedure is very important for solving optimization problems. The Armijo step-size rule, the Armijo-Goldstein step-size rule and the Wolfe-Powell step-size rule are three well-known line search methods. On the basis of the above three types of line search methods and the idea of the proximal point methods, a new class of step-size rules was proposed. Instead of a single objective function f, f ＋1/2（x - xk）^TBk（x-Xk） was used as the merit function in iteration k, where Sk is a given symmetric positive definite matrix. The existence of the steplength for the new rules was proved. Some convergence properties were also discussed.     

一个新的两点梯度法

构造一个新的解无约束优化问题的两点梯度法,类似共轭梯度法,在构造搜索方向时,充分利用上次迭代点的信息·采用强Powell-Wolf搜索准则产生步长,在较弱条件下,算法总体收敛,并且至少线性收敛·数值实验表明,在计算量和结果精度方面明显优于最速下降法·     

利用结构稀疏性的超宽带探地雷达检测成像算法

针对目前压缩感知(compressive sensing,CS)算法应用在超宽带探地雷达(ground penetrating radar,GPR)高分辨率检测成像过程中,传统稀疏字典的设计以及匹配追踪算法存在精确度不足的问题,提出块稀疏正交匹配追踪(block sparse orthogonal matching pursuit,BSOMP)算法,并引入地埋异质体检测成像研究。根据目标检测体在离散化后网格点之间反射回波具有相关性,以实际情况为基础创建稀疏字典,最终实验结果表明BSOMP能够实现对均匀介质探测体的精确成像。     

进藏游客旅游信息搜索行为研究

信息搜索是旅游活动的重要内容,贯穿整个旅游活动的始终。本文以世界旅游目的地——西藏为对象,重点研究进藏旅游者的信息搜索行为,从旅游信息源、内容搜索偏好、搜索行为特征、搜索者特征等四个方面进行阐述,以期为西藏旅游信息建设提供参考。