B2C E-commerce Logistic channel structure in China

The B2C e-commerce is fast developed in China, but the logistic activities are relatively lagged behind. So many of the B2C ecommerce corporations choose to run the logistic service on their own. The advantages and disadvantages of carrying on self-built logistic service are discussed. The research is to illustrate the choice of B2C corporations to carry on logistics service in China and to show the reason why choosing tree topology logistic network could be cost saving

Energy-saving Potential Study on Telecommunication Base Station Free Cooling With a Thermosyphon Heat Exchanger in China

The energy consumption of air conditioning for a telecommunication base station (TBS) in China can be significantly decreased when an air to air thermosyphon heat exchanger is used for free cooling in low atmosphere temperature days. The model for the typical TBS in China was established and the air conditioning energy consumption was analyzed for the cities with climatic data in China. Taking the sandwich steel panel envelope with the thickness of 50 mm for an example, the energy consumption of an air conditioner combined with a thermosyphon heat exchanger in a TBS and the energy-saving potential for using ambient energy were calculated, and were shown on the map of China by different colors according to the energy-saving rates. The static payback periods were also presented. The results demonstrate that the operation mode of the combined system of an air conditioner and a thermosyphon heat exchanger for controlling the indoor temperature can bring enormous energysaving potential for a TBS in different Chinese cities except the southern areas

A frequency-offset estimation algorithm combines code and time features for the remote reception of a weak satellite signal

Remote control technology has greatly expanded the intelligence and automation of industry. Satellite signals are important to keep in contact with the facilities and devices in remote areas. However, satellite channels suffer from multi-scale attenuation to achieve reliable communications, which cannot provide sufficient accuracy and suitable complexity for the frequency-offset estimation of a weak signal. Therefore, this paper focused on a frequency-offset estimation method for a weak signal from a distant, poor satellite channel. First, we built a model of a distant satellite channel with mirror power reflection, considering large fading and multi-path fading simultaneously. Second, we described M-Walsh pilots and a signal vector matrix as they relate to satellite signals. Initially, we analysed the performance of different frequency-offset estimation methods in the satellite environment as opposed to the ground environment. We proposed compact M-Walsh pilots locking correlation to improve the estimation accuracy, which enhanced the frequency tracking. We further proposed equivalent weighting estimation allocation to help improve the balance of accuracy and complexity in the algorithm. Simulations and tests demonstrated that the new algorithm enhanced the root-mean-square-error frequency-offset estimate by 36.2% and the bit-to-error rate) performance by 29.5%

A frequency-offset estimation algorithm combines code and time features for the remote reception of a weak satellite signal

Remote control technology has greatly expanded the intelligence and automation of industry. Satellite signals are important to keep in contact with the facilities and devices in remote areas. However, satellite channels suffer from multi-scale attenuation to achieve reliable communications, which cannot provide sufficient accuracy and suitable complexity for the frequency-offset estimation of a weak signal. Therefore, this paper focused on a frequency-offset estimation method for a weak signal from a distant, poor satellite channel. First, we built a model of a distant satellite channel with mirror power reflection, considering large fading and multi-path fading simultaneously. Second, we described M-Walsh pilots and a signal vector matrix as they relate to satellite signals. Initially, we analysed the performance of different frequency-offset estimation methods in the satellite environment as opposed to the ground environment. We proposed compact M-Walsh pilots locking correlation to improve the estimation accuracy, which enhanced the frequency tracking. We further proposed equivalent weighting estimation allocation to help improve the balance of accuracy and complexity in the algorithm. Simulations and tests demonstrated that the new algorithm enhanced the RMS (root mean square error) frequency-offset estimate by 36.2% and the Bit to Error Rate performance by 29.5%

Follicular dendritic cell sarcoma: a report of six cases and a review of the Chinese literature

<p>Abstract</p> <p>Goals</p> <p>The main purpose of this study is to broaden the clinicopathological spectrum and increase recognition of follicular dendritic cell sarcoma (FDCS) through analysis of the clinical and pathological features of 50 cases.</p> <p>Methods</p> <p>The clinicopathological features of total 50 cases of FDCS were analyzed including a review of 44 cases reported in Chinese literature before October 2009 and six original cases from the pathology files conducted by the authors.</p> <p>Results</p> <p>The youngest patient came under observation in this study is only seven years old. Including the cases contributed by the authors, our literary review indicated that male dominated the tumor cases (M: F = 3: 2). 28 cases (56%) present with this disease in extranodal sites. Tumor cells demonstrated positive staining for the follicular dendritic cell markers CD21 (47/49), CD35 (43/45), CD23 (20/23) and CD68 (23/25). In situ hybridization for Epstein-Barr virus-encoded RNA was performed in 10 cases. Nevertheless, EBV expression was absent in all these cases. The follow-up analysis of all cases shows that 26 (81.2%) patients were alive and disease free; 6 (18.8%) patients were alive with recurrent disease or metastasis; and nobody had died of this disease at the time of last follow-up.</p> <p>Conclusions</p> <p>The diagnosis of the FDCS is based on the findings of morphology and immunohistochemistry. The FDCS occurred in China should be viewed and treated as a low-grade sarcoma, and the role of the EBV in the pathogenesis of this tumor is still uncertain. There is a possibility that the tumor might be racial or geographic correlated, because most cases were reported from Eastern Asia area; it's particular the case of the liver or spleen tumor.</p

Carbon Emission Cost Affects Location Decision: CO2 Efficient Area Yields to the Less Efficient

Due to the global warming problem, it is more urgent than ever to take carbon emission problem seriously. It is needed to take carbon emission cost into consideration. Gravity method is used to do location selection. Three aspects of work have been done. First, the carbon emission cost of a certain kind of truck is calculated. Second, the comparison between considering and not considering carbon emission is done. Third, a distance parameter is added to transfer straight-line distance to real distance. The research gets the result in two cases: case 1 single mode transportation tools are used, the best site has no changes with total cost rising case 2 multi-mode transportation tools are used, the best site coordination has changed with cost rising in general except extraordinary case. At the end, we show the application of the model. The carbon emission cost affects the location modeling, the cost like carbon dioxide tax will drive the location center to move a little bit in the direction of the CO2 efficient area towards less efficient area.nbs