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An inclined sidewall scattering structure with air cavity characterized by a metal bottom and flat parallel top (Bottom_metal) is proposed to enhance the light extraction efficiency (LEE) for AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs). Compared to the reported sidewall metal inclined sidewall (Sidewall_metal) structure, the Bottom_metal structure can greatly enhance the LEE of DUV...
In this paper, we investigate the electron injection efficiency in terms of different polarities and different polarization charge densities at the ${\rm{GaN/ InGaN}}$ interface. We find that the growth orientation for the ${\rm{GaN/ InGaN}}$-type last quantum barrier is essentially vital, i.e., the ${\rm{GaN/ InGaN}}$-type last quantum barrier is not able to effectively reduce the electron leakage...
A new packet-selection based transmission scheme is proposed on a dual-hop link with buffer aided amplify-and-forward relay, where the relay with a buffer can record the channel information of source-relay hop and store the received packets. In order to satisfy the constraint of equivalent end-to-end SNR, the relay may pick up a packet in the buffer to transmit, with consideration of the channel statuses...
Considering the characteristics of ERA based wireless sensor networks architecture and the specific demand of tropical agriculture, this paper proposes a scheme which can be used in high temperature, multiple rain and so on, design and implementation wireless sensor network system of tropical agriculture. ERA is a new type of embedded architecture with the use of reconfigurable architecture, and the...
This paper presented the mathematical models of load three-phase equilibrium optimal allocation in low-voltage power network, studied the commonly used graphical modeling method based on the painted electric writing diagram of low-voltage power network. Using Visio 2003 we developed a practical auxiliary system of calculating the line loss in low-voltage network and load optimal allocation. It is...
In the phase measurement of three-phase electricity signal, the measurement accuracy based on traditional FFT algorithm is restricted by harmonic components. Even though it can be corrected by some spectrum correction algorithm, such as FFT+DFT spectrum continuous refining method, phase difference method and so on, these correction algorithms are based on FFT results. So the precision is very limited...
Mobile Internet access becomes a major research focus with the increase of mobile phones. This paper introduced and summarized a variety of wireless technologies supporting mobile Internet access. Firstly, the current progressing wireless access technologies were valued on their strengths and weaknesses. Then the newest mobility support researches and progresses over IP layer, such as MIP, NEMO, SIP...
In this paper the order conditions for Runge-Kutta (RK) methods are presented based on Butcher's B-series theory. New concepts of internal orders vector and stage orders of RK methods are proposed. The internal and stage orders of some classical RK methods are examined. Two new methods with improved internal orders are constructed. The results of numerical experiments show the competence of the new...
Like traditional server farm, DHT-based server farm has high requirement on load balancing. Traditional solutions to balance load in DHTs either can not satisfy the requirement of server farm, or incur a high overhead. This paper presents a novel load balancing algorithm designed for server farm. Compared with the traditional virtual nodes algorithm, our algorithm generates the virtual IDs in the...
It is an important and urgent task to achieve remote container monitoring and management when the containers are being transported anytime, anywhere. For this purpose, this paper first proposes a wireless networking system suitable for collecting and transmitting the status and location information of the transported containers. The proposed wireless networking system integrates RFID, sensors, ZigBee,...
China's networks and railways develop rapidly, which urgently requires mobile Internet access. However there exist challenges on network integration of access schemes, on network applications of the transition period, on high cost of all-coverage access, on high bit error rate, on frequent interruption, and on traffic explosion. The proposed multi-homing hierarchy DTN-based train mobile Internet access...
Chinese broadband network is developing rapidly but still far from all coverage for countryside areas, the island of information. Current distance education content is of large multi-media with large bandwidth. So it is critical for education platform to deliver the massive content timely and effectively, yet low-cost, even to the terminals without broadband coverage. Analyzed current mobile Internet...
Access to Internet is still a challenge in the area without fully network-coverage. Limited to a predictable environment (such as trains), the problem can be simplify and be solved partially with the proposed general k-anycast routing and Delay and Disruption Tolerant Networking (Ganycast). How to forward the packets efficiently is core issue of Ganycast. Access router information matrixes were proposed...
K-anycast in disruption tolerant network (DTN) can multi-path custody transfer packets for the area without fully network-coverage Internet access, after gotten circumstance information. In this paper, connection judgment logic is proposed for distinguishing mobile circumstance. Probabilistic routing protocols have poor performance in the mobile node cyclical movement environment, so TTL equivalent...
Mobile Internet access is for the ubiquitous Internet, facing traffic explosion, frequent interruption and network partitioning. DTN-based Ferry Prefetch Scheme (DFP) was designed to increase quality of service on area without broadband wireless networks coverage. Based on bit paradox, Pareto effect and strong substitutability of local resources, DFP proposed a cache overlay layer for media distributaries,...
Utility function recently has been adopted in network studies to describe quality of service. However, the existing utility functions focus only on the effect of power or throughput, so are not suitable to delay and disruption tolerant networking (DTN), where delay and disruption have major impacts on the utility and cannot be ignored. This paper proposes a corresponding sigmoid utility function,...
Quality of Services optimal models often based on the utility function maximization. However the services in Delay and Disruption Tolerant Networking (DTN) have different characters on delay and disruption. So a novel utility function was made to analyze resource pre-fetching and post-fetching in DTN and to prove the relational Pareto improvement and substitutability. Then users' competitions were...
The thesis briefly introduced data mining and clustering theories. Also through K-Means, ADSL voice multiplex customers are clustered, which caused over 240,000 customers divided into 8 clusters. Further analysis showed that the 8 clusters had distinct differences in basic characters and surfing the net. However, these differences could help X telecom Co. to design pointed sales strategies respectively,...
DHT (Distributed Hash Table) algorithms are very efficient for distributed data storage and retrieval. As one kind of P2P overlay, DHT overlay also has the advantages of high reliability, high scalability and low cost. DHT has not only been applied to form user nodes' overlays, but also been proposed to form DHT-based server farms, such as DHT-based SIP server farm, HSS server farm, DNS server farm,...
The fundamental theory of topological optimization was enunciated in this paper, and topological optimization method provided by ANSYS software was used to optimize the structure of rear platen of injection molding machine. The optimal structure was found out and it provides the theoretical base for further improving the platenpsilas structure.
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