Challenges of Vietnamese Agricultural Cooperatives in the 21st Century:The Link Between Efficiency and Legality

The article shows that the situation of agricultural cooperatives in the world in general and agricultural cooperatives in Vietnam in particular are facing certain challenges in the context of globalization in the 21st century.The article points out limitations on:the nature,principles of democratic member control and principles of surplus distribution of the International Cooperative Alliance,as well as Vietnamese law in cooperative management.

Twin Prime Distribution Problem

The distribution of twin prime numbers is discussed. The research method of corresponding prime number distribution is proposed. The distribution of prime numbers corresponding to integers and composite numbers is discussed. Through the corresponding prime distribution rate of integers and composite numbers, it is found that the corresponding prime distribution rate of composite numbers approaches the corresponding prime distribution rate of integers. The distribution principle of corresponding prime number of composite number is proved. The twin prime distribution theorem is obtained. The number of twin prime numbers is thus obtained. It provides a practical way to study the conjecture of twin prime numbers.

A research on development of agritourism in China-a case study of Beijing

Agritourism is a new kind of industry which combined agriculture with tourism and started from the 1970s with the development of agricultural economy and meeting the demand of touring consumption. It is an important way to exploit natural resources sufficiently, change the simplistic structure and promote the high efficient agriculture. It provides a new space for people to enjoy themselves and appreciate rural scenery. In light of its function, it can be classified into sightseeing, dietetics, shopping, recreation, leisure, health and vocationing. At present, most agritourism is concentrated at the suburbs of big cities, comparative developed regions along the seashore, scenic spots nationalities inhabited areas and regions of special agriculture. Beijing is a metropolis where tourism is comparatively well developed with advantageous conditions. Agricultural landscape is the theoretical base of agritourism. So it is important to construct agricultural landscape and artificial landscape is the premise to develop agritourism.

Sampled-data based average consensus with measurement noises: convergence analysis and uncertainty principle

In this paper, sampled-data based average-consensus control is considered for networks consisting of continuous-time first-order integrator agents in a noisy distributed communication environment. The impact of the sampling size and the number of network nodes on the system performances is analyzed. The control input of each agent can only use information measured at the sampling instants from its neighborhood rather than the complete continuous process, and the measurements of its neighbors＇ states are corrupted by random noises. By probability limit theory and the property of graph Laplacian matrix, it is shown that for a connected network, the static mean square error between the individual state and the average of the initial states of all agents can be made arbitrarily small, provided the sampling size is sufficiently small. Furthermore, by properly choosing the consensus gains, almost sure consensus can be achieved. It is worth pointing out that an uncertainty principle of Gaussian networks is obtained, which implies that in the case of white Gaussian noises, no matter what the sampling size is, the product of the steady-state and transient performance indices is always equal to or larger than a constant depending on the noise intensity, network topology and the number of network nodes.