Linear discriminant analysis (LDA) is a popular method among pattern recognition algorithms of machine olfaction. However, “Small Sample Size” (SSS) problem would occur while using LDA algorithm with traditional Fisher criterion if the within-class scatter matrix is singular. In this paper, maximum scatter difference (MSD) criterion and LDA were combined to solve SSS problem, so that three kinds of Chinese herbal medicines from different growing areas were accurately classified. At the same time, the classification result was enhanced. It works out that only a few samples of Anhui Atractylodes are classified incorrectly, however, the classification rate reaches 97.8%.

In machine olfaction or electronic nose, sensor optimization is important to enhance pattern recognition efficiency and reduce redundant information. Highly correlated response of one sensor to two different odors implies less contribution of this sensor to the classification of these two odors. Variance difference is a significant index to measure the similarity of sensor responses. A sensor optimization method based on variance difference is proposed in this paper; both the average value of variance difference and cluster analysis of variance difference matrix were considered to identify several possible sensor subsets. Six Chinese herbal medicines and linear discrimination analysis (LDA) were applied to test the classification results in order to determine the best subset. LDA results indicated that the optimized sensor subset performed well in classification of the six Chinese medicines. The proposed sensor array optimization method could be applied to other kinds of odors classification as a novel method.

Nowadays, wireless network technology in smart home is rapid gaining popularity duo to its flexible integration into everyday life. The paper introduces a method that adopts 433MHZ communication to establish the wireless network in smart home system based on Si4421 wireless modules. The paper designed the overall idea of how to establish the wireless network, it mainly talk about the wireless module, including both software and hardware. The difficulty lies in the realization of the custom wireless communication protocol. The Si4421 wireless module was tested in data communication and control in smart home system which can work efficiently and reliably, it proved that the wireless module is perfectly suitable for the wireless network construction in smart home with small size package, low consumption, low cost, and strong ability to leap obstacles.

Efforts to prepare for a growing number of elderly patients, reducing the escalation of healthcare costs, and avoiding hospitals emergency room overcrowding are some of the driving forces for adopting wireless healthcare monitoring systems. However, due to the open-to-air commination nature of multilayer wireless networks, it is important to consider reliability, accuracy, security and privacy of such data transmission. We have developed a low-cost and wireless telehealthcare system for monitoring of basic physiological parameters and automatically transmitting the measured data to an electronic patient record. It employs off the shelf wireless products and a secure web-based application which have been tested in a hospital with satisfactory outcomes.

A new feedback optimization design method based on arithmetic sequence is proposed to design free-form optical systems for an extended LED source. Taken LED lens designed by this method as an example, we find that the design process is simple and high regional illuminance uniformity and high light output efficiency could be simultaneously achieved.