Ethernet Ring Protection (ERP) introduced by ITU-T G.8032 Recommendation is a new type of packet-switched network protection technology, which can provide ring automatic protection switch. However, the Filtering Datab...Ethernet Ring Protection (ERP) introduced by ITU-T G.8032 Recommendation is a new type of packet-switched network protection technology, which can provide ring automatic protection switch. However, the Filtering Database (FDB) flush method adopted in the current ERP standard has the drawback of introducing a large amount of transient traffic overshoot caused by flooded Ethernet frames right after protection switching. In this article, we propose a G.8032 ERP scheme that uses FDB flush based on area to resolve this issue and investigate how the proposed scheme deals with the traffic flooding problem. The theoretical analysis and simulation show that the proposed scheme can effectively improve the performance of the Ethernet ring by decreasing the unnecessary FDB flush in comparison with the existing approaches.展开更多
The effects of soil and water conservation （SWC） on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lack...The effects of soil and water conservation （SWC） on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lacking for hilly red soil region of southern China. Experiments were conducted in the hilly red soil region of southern China for seven years in three rtmoffplots, each of which represented different SWC forest-grass measures. Principal component analysis and multiple regression techniques were used to relate the aboveground biomass （representing soil productivity） to soil properties. Based on the final regression equations, soil organic carbon content （Sot） is significantly correlated with soil productivity under the condition of forest-grass measures, whereas pH value and cation exchange capacity （Cee） are the main factors for soil productivity without SWC. Therefore, SWC plays an important role in sequestering Soc and improving soil productivity.展开更多
The active-fault-alarm （AFA） technologies and the dynamic protection mechanism of the optical network controlled by the multi-protocol label switching transport profile （MPLS-TP） are both studied in this article. ...The active-fault-alarm （AFA） technologies and the dynamic protection mechanism of the optical network controlled by the multi-protocol label switching transport profile （MPLS-TP） are both studied in this article. On this basis, an active dynamic pre-protection （ADPP） mechanism is proposed. This active dynamic pre-protection mechanism is allowed to establish a so called temporary protection path （TPP） for the work path before a potential fault occurs and to switch to TPP only after the fault occurs. It keeps the TPP flexibly only when it is in low- quality or fault state to realize dynamic protection even better and to achieve better resource utilization. Simulation results show that the proposed new mechanism has better performance in terms of the flexibility and the efficiency from the perspective of time.展开更多
Residents living in the cold areas such as Harbin generally experience a residence time of approximately 6 months in chilly winter without frequent natural ventilation. To find out the influence of a short period of v...Residents living in the cold areas such as Harbin generally experience a residence time of approximately 6 months in chilly winter without frequent natural ventilation. To find out the influence of a short period of ventilation on the indoor formaldehyde concentration inside a new building, an investigation was conducted for the instance of twice ventilation in a day through window opening. The results showed that the initial concentration of formaldehyde was 3.53 -8. 48 times as high as the concentration after 10 min ventilation. After closing the window, the indoor formaldehyde concentration increased with time and followed an exponential equation of C = C0 exp（ - b ＊ t） ＋ （ a ＋ Cu, ） [ 1 - exp（ - b ＊ t） ] with correlation coefficient （ R^2 ） of 0. 945 - 0. 999, based on the statistical analysis of 14 groups of measurement data. The developed equation can be used to estimate the emission rate of indoor formaldehyde sources and the air exchange rate of the test room simultaneously.展开更多
Andean grasslands ecosystems are fragile environments with rigorous climatologic conditions and low and variable food for the grazing. The Apolobamba area is located in the Bolivian Andean Mountains. Its high grasslan...Andean grasslands ecosystems are fragile environments with rigorous climatologic conditions and low and variable food for the grazing. The Apolobamba area is located in the Bolivian Andean Mountains. Its high grasslands provide a natural habitat for wild and domestic camelids such as vicuna(Vicugna vicugna) and alpaca(Lama pacos). The botanical diversity plays an essential role in maintaining vital ecosystem functions. The objectives of this research were to determine the seasonal changes in soil properties, to study the vegetation changes during the wet and dry seasons and the influence of soil properties and camelid densities on the vegetation in the Apolobamba grasslands. Four zones with different vicuna populations were selected to be studied. The following soil parameters were determined: total organic carbon, total nitrogen, available phosphorous, cation exchange capacity, exchangeable cations, pH and texture. The vegetation season changes were studied through botanical identification, above-ground biomass, plant cover and species richness. Results showed that some soil properties such as C/N ratio, CEC, silt and clay percentages kept stable against the seasonal changes. Generally, soil nutrients were relatively higher during the dry season in the surface and subsurface. The results did not point out the predominant vegetation growth during the wet season. The seasonal vegetation growth depended on each species. Thegood soil fertility corresponded to the highest plant cover. Soil fertility presented no influence on the above-ground biomass of the collected species. The negative influence of camelid grazing on soil properties could not be assessed. However, overgrazing could affect some plant species. Therefore, protection is needed in order to preserve the biodiversity in the Andean mountain grasslands.展开更多
Using the highly entangled six-qubit genuine state we present a quantum private comparison(QPC)protocol, which enables two users to compare the equality of two bits of their secrets in every round comparison with the ...Using the highly entangled six-qubit genuine state we present a quantum private comparison(QPC)protocol, which enables two users to compare the equality of two bits of their secrets in every round comparison with the assistance of a semi-honest third party(TP). The proposed protocol needs neither unitary operations nor quantum entanglement swapping technology, both of which may consume expensive quantum devices. Single particle measurements and Bell-basis measurements, which are easy to implement with current technologies, are employed by two users and TP in the proposed protocol, respectively. The proposed protocol can withstand all kinds of outside attacks and participant attacks. Moreover, none of information about the two users' private secrets and the comparison result is leaked out to TP.展开更多
基金supported partially by National Science and Technology Major Project of the Ministry of Science and Technology of China under Grant No.2011ZX03005-004-03 a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions-Information and Communication Engineering,Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China under Grant No.10KJA510037+1 种基金 Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology（Nanjing University of Posts and Telecommunications）,Ministry of Education under Grant No.NYKL201108 Natural Science Foundation of Nanjing University of Posts and Telecommunications under Grant No.NY209002
文摘Ethernet Ring Protection (ERP) introduced by ITU-T G.8032 Recommendation is a new type of packet-switched network protection technology, which can provide ring automatic protection switch. However, the Filtering Database (FDB) flush method adopted in the current ERP standard has the drawback of introducing a large amount of transient traffic overshoot caused by flooded Ethernet frames right after protection switching. In this article, we propose a G.8032 ERP scheme that uses FDB flush based on area to resolve this issue and investigate how the proposed scheme deals with the traffic flooding problem. The theoretical analysis and simulation show that the proposed scheme can effectively improve the performance of the Ethernet ring by decreasing the unnecessary FDB flush in comparison with the existing approaches.
基金Project(40971170) supported by the National Natural Science Foundation of ChinaProject(NCET-09-330) supported by the Program for New Century Excellent Talents in University of China
文摘The effects of soil and water conservation （SWC） on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lacking for hilly red soil region of southern China. Experiments were conducted in the hilly red soil region of southern China for seven years in three rtmoffplots, each of which represented different SWC forest-grass measures. Principal component analysis and multiple regression techniques were used to relate the aboveground biomass （representing soil productivity） to soil properties. Based on the final regression equations, soil organic carbon content （Sot） is significantly correlated with soil productivity under the condition of forest-grass measures, whereas pH value and cation exchange capacity （Cee） are the main factors for soil productivity without SWC. Therefore, SWC plays an important role in sequestering Soc and improving soil productivity.
基金Supported by the National High Technology Research and Development Program of China（No. 2009AA01Z255, 2009AA01A345）, the National Basic Research Program of China（No. 2007CB310705 ） and the National Natural Science Foundation of China（No. 60932004）.
文摘The active-fault-alarm （AFA） technologies and the dynamic protection mechanism of the optical network controlled by the multi-protocol label switching transport profile （MPLS-TP） are both studied in this article. On this basis, an active dynamic pre-protection （ADPP） mechanism is proposed. This active dynamic pre-protection mechanism is allowed to establish a so called temporary protection path （TPP） for the work path before a potential fault occurs and to switch to TPP only after the fault occurs. It keeps the TPP flexibly only when it is in low- quality or fault state to realize dynamic protection even better and to achieve better resource utilization. Simulation results show that the proposed new mechanism has better performance in terms of the flexibility and the efficiency from the perspective of time.
基金Sponsored by the Scientific and Technically Key Project of Heilongjiang Province(Grant No.GC04C213).
文摘Residents living in the cold areas such as Harbin generally experience a residence time of approximately 6 months in chilly winter without frequent natural ventilation. To find out the influence of a short period of ventilation on the indoor formaldehyde concentration inside a new building, an investigation was conducted for the instance of twice ventilation in a day through window opening. The results showed that the initial concentration of formaldehyde was 3.53 -8. 48 times as high as the concentration after 10 min ventilation. After closing the window, the indoor formaldehyde concentration increased with time and followed an exponential equation of C = C0 exp（ - b ＊ t） ＋ （ a ＋ Cu, ） [ 1 - exp（ - b ＊ t） ] with correlation coefficient （ R^2 ） of 0. 945 - 0. 999, based on the statistical analysis of 14 groups of measurement data. The developed equation can be used to estimate the emission rate of indoor formaldehyde sources and the air exchange rate of the test room simultaneously.
基金the Spanish Agency of Cooperation and Development (AECID)
文摘Andean grasslands ecosystems are fragile environments with rigorous climatologic conditions and low and variable food for the grazing. The Apolobamba area is located in the Bolivian Andean Mountains. Its high grasslands provide a natural habitat for wild and domestic camelids such as vicuna(Vicugna vicugna) and alpaca(Lama pacos). The botanical diversity plays an essential role in maintaining vital ecosystem functions. The objectives of this research were to determine the seasonal changes in soil properties, to study the vegetation changes during the wet and dry seasons and the influence of soil properties and camelid densities on the vegetation in the Apolobamba grasslands. Four zones with different vicuna populations were selected to be studied. The following soil parameters were determined: total organic carbon, total nitrogen, available phosphorous, cation exchange capacity, exchangeable cations, pH and texture. The vegetation season changes were studied through botanical identification, above-ground biomass, plant cover and species richness. Results showed that some soil properties such as C/N ratio, CEC, silt and clay percentages kept stable against the seasonal changes. Generally, soil nutrients were relatively higher during the dry season in the surface and subsurface. The results did not point out the predominant vegetation growth during the wet season. The seasonal vegetation growth depended on each species. Thegood soil fertility corresponded to the highest plant cover. Soil fertility presented no influence on the above-ground biomass of the collected species. The negative influence of camelid grazing on soil properties could not be assessed. However, overgrazing could affect some plant species. Therefore, protection is needed in order to preserve the biodiversity in the Andean mountain grasslands.
基金Supported by National Natural Science Foundation of China under Grant No.61402407
文摘Using the highly entangled six-qubit genuine state we present a quantum private comparison(QPC)protocol, which enables two users to compare the equality of two bits of their secrets in every round comparison with the assistance of a semi-honest third party(TP). The proposed protocol needs neither unitary operations nor quantum entanglement swapping technology, both of which may consume expensive quantum devices. Single particle measurements and Bell-basis measurements, which are easy to implement with current technologies, are employed by two users and TP in the proposed protocol, respectively. The proposed protocol can withstand all kinds of outside attacks and participant attacks. Moreover, none of information about the two users' private secrets and the comparison result is leaked out to TP.
