The existing operation and maintenance system of photovoltaic power station can analyze partial equipment problems, but due to the data storage, processing and transmission capacity can hardly meet the requirements of a large number of operation data acquisitions and processing of photovoltaic power station, the operation status of photovoltaic power station cannot be comprehensively evaluated. This paper proposes to analyze the overall efficiency and key link efficiency of the photovoltaic system through long-term monitoring, extract the efficiency model parameters of the key components and important links of the photovoltaic power station, and establish the performance evaluation implementation process. At the same time, based on different actual detection conditions, photovoltaic fault diagnosis is carried out by time domain reflectometry, prediction theory comparison and sensor optimization.
Mobile social network service has gained worldwide popularity among users nowadays. This paper proposes a campus-oriented and opened mobile social networking system for university students and faculties, to build a reliable trust relationship network on campus. It utilizes the campus wireless network and mobile devices to provide dynamic location-based social network services for users anytime and anywhere. This paper designs a system architecture based on Widget/Server mode. The system combines traditional social networking functions with context-aware technology, and precisely recommends friends based on Friend of a Friend ontology description.The future applications of campus mobile social networking system are also discussed.
Uncertainty evaluation of dynamic repeated measurement is usually a difficult problem. Different from conventional methods, we used a novel method to evaluate the dynamic repeated measurement uncertainty in this paper: (1) When calculating an expectation function, we use a high order Legendre orthogonal polynomial fitting instead of the least squares method, so as to eliminate morbidity phenomenon that sometimes appeared in the application of the conventional method. (2) Using the measurement data and the accurate expectation function, we analyze some statistical characteristics of the dynamic repeated measurement random errors, according to these, we use a random number generator to generate lots of random numbers simulating the random errors in all discrete sampling points and acquire a large size of dynamic repeated measurement simulation data. (3) We get the dynamic repeated measurement uncertainty of all discrete sampling points in terms of calculating standard deviation. Finally, using a special example, we derived some evaluation results from this novel method, the conventional Bessel method and the conventional Grey System method, respectively. This novel evaluation method is proved by the identical results of the three methods.
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