平面广告设计中的象征研究

一、平面广告中的象征现象 平面广告是以平面视觉形象向大众传达某种意义的一种广告类型意义体现了人与社会、自然、他人、自己的种种复杂交错的文化关系，历史关系心理关系时间关系。意义的传达、探寻与阐释是人类的本性需求．它实际上是人类认识自己、认识世界的活动的最主要方面，因而是人类最基本的活动之一。     

Automatic feature selection for unsupervised clustering of cycle-based signals in manufacturing processes

Recent developments in sensing and computer technology have resulted in most manufacturing processes becoming a data-rich environment. A cycle-based signal refers to an analog or digital signal that is obtained during each repetition of an operation cycle in a manufacturing process. It is a very important class of in-process sensing signals for manufacturing processes because it contains extensive information on the process condition and product quality (e.g., the forming force signal in forging processes). In contrast with currently available supervised classification approaches that heavily depend on the training dataset or engineering field knowledge, this paper aims to develop an automatic feature selection method for the unsupervised clustering of cycle-base signals. First, principal component analysis is applied to the raw signals. Then a new method is proposed to select information containing principal components to allow clustering to be performed. The dimension of the problem can be significantly reduced through the use of these two steps. Finally, a model-based clustering method is applied to the selected principal components to find the clusters in the cycle-based signals. A numerical example and a real-world example of a forging process are used to illustrate the effectiveness of the proposed method. The proposed technique is an important data pre-processing technique for the monitoring and diagnostic system development using cycle-based signals for manufacturing processes.     

中空纤维膜氢回收系统在制氢装置的应用

简述了中空纤维膜分离原理、开车步骤，分析了中空纤维膜氢回收系统标定数据，指出存在的问题，并进一步对比分析了加氢干气直接作为制氢原料和用中空纤维膜氢回收系统的非渗透气作为制氢原料的优缺点．