Mixed Broadcast Techniques of Leisure Information in Vehicular Ad-Hoc Networks

Telecommunication Systems - Vehicle-to-vehicle communication and probabilistic broadcast are important means for information dissemination in vehicular ad-hoc networks (VANETs). In contrast to...     

Cobalt Recovery by the Chlorination-Volatilization Method

Metallurgical and Materials Transactions B - This communication presented the chlorination-volatilization of cobalt using calcium chloride. Effects of variables on the cobalt volatilization rate...     

An energy-aware routing protocol for wireless sensor network based on genetic algorithm

Energy saving and effective utilization are an essential issue for wireless sensor network. Most previous cluster based routing protocols only care the relationship of cluster heads and sensor nodes but ignore the huge difference costs between them. In this paper, we present a routing protocol based on genetic algorithm for a middle layer oriented network in which the network consists of several stations that are responsible for receiving data and forwarding the data to the sink. The amount of stations should be not too many and not too few. Both cases will cause either too much construction cost or extra transmission energy consumption. We implement five methods to compare the performance and test the stability of our presented methods. Experimental results demonstrate that our proposed scheme reduces the amount of stations by 36.8 and 20% compared with FF and HL in 100-node network. Furthermore, three methods are introduced to improve our proposed scheme for effective cope with the expansion of network scale problem.     

Viscosity of CaO–MgO–Al2O3–SiO2 melts containing SiC particles

The influence of SiC particle on viscosity of CaO–MgO–Al₂O₃–SiO₂ melts was investigated by the rotating-cylinder method. It was found that temperature dependence of viscosity could be described by the Arrhenius law for systems with or without SiC particle addition. The activation energies of liquid–solid mixtures were mainly determined by liquid phase. Temperature had little influence on the relative viscosity (defined as the viscosity ratio of solid–liquid mixture to pure liquid). Viscosity and relative viscosity increased as decreasing rotation speed and increasing volume fraction of SiC solid particle. For the same volume fraction of SiC particle, relative viscosity was affected by the liquid slag compositions. The relative viscosity was smaller when composition of liquid slag had a larger CaO/SiO₂ ratio or MgO/Al₂O₃ ratio. Meanwhile, it was found that the smaller SiC particle will lead to a larger relative viscosity.     

计算机在催化剂催化活性评价中的应用

催化剂的加氢裂化一抑焦活性是影响渣油悬浮床加氢工艺工业化的一个关键因素，因此在催化剂复配筛选过程中，采取一种合理公正的方法来评价催化剂的活性就显得更为重要。由于催化剂浓度与其加氢裂化一抑焦活性之间符合二次曲线关系，因此本文利用最小二乘法拟合了反映它们之间关系的二次曲线方程，并计算出催化活性最大处的浓度。为了使所编的程序简洁、高效，本文采用了C语言作为编程语言。     

More efficient location tracking in PCS systems using a noveldistributed database system

In personal communication services (PCS), the complete location information and subscribers' profiles are kept in a database called the home location register (HLR). Another database, the visitor location register (VLR), is used to store partial location information. When a mobile user is called, the system queries the HLR to determine the location of the called party. Distributed databases have been introduced to improve the efficiency of querying the HLR. This paper presents an alternative means of constructing a distributed database. The proposed database design employs fixed pointers to link distributed data. Each database contains a portion of the system's information as well as several pointers. The pointers identify the location of real data, enabling the system to obtain the required information efficiently. The database of the proposed design is markedly smaller than the fully distributed databases since each database of the proposed design stores only partial information. Subscriber information is stored only in one database, thus allowing a single database, rather than multiple databases, to be updated. The single update presented herein notably reduces the signal traffic load. If the caller is in the registration area of some HLR, which holds the called party's information, the response time is significantly decreased since the transactions are served only by the local database. This phenomenon is referred to as the calling locality. The proposed method effectively shares the database and the network loading that originates from several databases' tracking mobile users in a PCS system. According to the results presented, this method is highly effective for systems with a heavy load and high calling locality. The single update feature of the proposed design reduces the traffic in the signaling link and the processing load of a database. However, the proposed method includes no fault tolerance and therein differs from the fully distributed design     

First proof-of-principle experiment with the post-accelerated isotope separator on-line beam at BRIF: measurement of the angular distribution of $$^{23}$$ Na + $$^{40}$$ Ca elastic scattering

Nuclear Science and Techniques - Non-evaporable getter (NEG) films are an integral part of many particle accelerators. These films provide conductance-free evenly distributed pumping, a low thermal...     

Minimization of delay and collision with cross cube spanning tree in wireless sensor networks

Wireless Networks - The wireless sensor network (WSN) is a system containing the event detection and the data gathering abilities. The data gathering mechanism is the fundamental but important...