Location Based Service (LBS) is gaining popularity. As one fundamental LBS service, range search returns all Point of Interests (POIs) within a user-specified range. However, people also leave their location privacy at risks when using range search. How to provide a high-quality range search service while protecting users' location privacy is a challenging problem. Most existing approaches use space-filling curves and cloaked region method to provide privacy-preservation location services, but these methods cannot return the accurate results. In this paper, we propose a set of Circular Shifting Encryption Protocols (CSEP) based on homomorphism and circular shift for location privacy protection of range search. CSEP leverages homomorphic encryption to encrypt users' locations, and LBS servers compute distances on cyphertext. In this way, LBS server can return POIs within the specified range, while learning nothing about the user's real location. To accommodate the different query range and the private protection degree of users, we propose a circular shifting encryption method to reduce the redundancy and increase the degree of privacy protection. We implement a prototype of CSEP, and evaluate it with real POI set of a large-scale production LBS. Experimental results show that CSEP can provide reliable privacy protection and accurate range search, with reasonable compute overhead and communication overhead.

Despite the simplicity of the scheme of treating interference as noise (TIN), it was shown to be sum-capacity optimal in the Gaussian interference channel (IC) with very-weak (noisy) interference. In this paper, the two-user IC is altered by introducing an additional transmitter that wants to communicate with one of the receivers of the IC. The resulting network thus consists of a point-to-point channel interfering with a multiple access channel (MAC) and is denoted by PIMAC. The sum-capacity of the PIMAC is studied with main focus on the optimality of TIN. It turns out that TIN in its naive variant, where all transmitters are active and both receivers use TIN for decoding, is not the best choice for the PIMAC. In fact, a scheme that combines both time division multiple access and TIN (TDMA-TIN) strictly outperforms the naive-TIN scheme. Furthermore, it is shown that in some regimes, TDMA-TIN achieves the sum-capacity for the deterministic PIMAC and the sum-capacity within a constant gap for the Gaussian PIMAC. In addition, it is shown that, even for very-weak interference, there are some regimes where a combination of interference alignment with power control and TIN at the receiver side outperforms TDMA-TIN. As a consequence, on the one hand, TIN in a cellular uplink is approximately optimal in certain regimes. On the other hand, those regimes cannot be simply described by the strength of interference.

For the present hospital management information system which lacked of data availability situation, this study was designed and implemented comprehensive query system of patients. The system can provide various forms of statistical analysis of patients for hospital administrators. After the system implementing in the hospital, it can effectively improved the utilization of data, help managers make decisions and made hospital's information technology and management to higher level.

For the present hospital management information system which lacked of data availability situation, this study was designed and implemented comprehensive query system of patients. The system can provide various forms of statistical analysis of patients for hospital administrators. After the system implementing in the hospital, it can effectively improved the utilization of data, help managers make decisions and made hospital's information technology and management to higher level.