In this letter, we analyze the drawback of tail-dropping contention resolution in optical burst switched networks. Once contention occurs, we adopt modified head-dropping policy to resolve contention. This policy drop...In this letter, we analyze the drawback of tail-dropping contention resolution in optical burst switched networks. Once contention occurs, we adopt modified head-dropping policy to resolve contention. This policy drops the head of the contending burst only if the overlapping region of the two bursts is less than the whole contending burst size, otherwise drops the whole contending burst. In order to have a better support of differentiated service, a new burst assembly policy, namely, Priority-based proportional mixed burst assembly, is proposed. Simulation results show that the proposed scheme performs very well in terms of performance metrics such as the times of contention and packet loss probability.展开更多
Based on the design principles of economic rationality and safety,multiple-pivot pile anchorage approach was used as the supporting engineering of a tall building with a deep foundation ditch.The designs,such as ancho...Based on the design principles of economic rationality and safety,multiple-pivot pile anchorage approach was used as the supporting engineering of a tall building with a deep foundation ditch.The designs,such as anchor arm,single pile and the whole,were set up in accordance with the calculations of the internal force from the equivalent beam and Yamagata Kunio methods.Moreover,the rationality of the design was estimated using the stability checks.FLAC3D was used for calculating the accuracy of the design.Using FLAC3D to simulating ditch cutting and supporting processes can obtain the equivalent results as the theory analysis in the displacement of ditch surrounding wall,the stress field and stress distribution.展开更多
University College Dublin(UCD) has implemented the Output-Based Research Support Scheme(OBRSS) since 2016. Adapted from the Norwegian model, the OBRSS awards individual academic staff using a points system based on th...University College Dublin(UCD) has implemented the Output-Based Research Support Scheme(OBRSS) since 2016. Adapted from the Norwegian model, the OBRSS awards individual academic staff using a points system based on the number of publications and doctoral students. This article describes the design and implementation processes of the OBRSS, including the creation of the ranked publication list and points system and infrastructure requirements. Some results of the OBRSS will be presented, focusing on the coverage of publications reported in the OBRSS ranked publication list and Scopus, as well as information about spending patterns. Challenges such as the evaluation of the OBRSS in terms of fairness, transparency, and effectiveness will also be discussed.展开更多
As we all know, the most important factor for a high-rise building to stand is to lay a good foundation and make it safe and reliable. Before the construction of foundation, the foundation should be excavated first. I...As we all know, the most important factor for a high-rise building to stand is to lay a good foundation and make it safe and reliable. Before the construction of foundation, the foundation should be excavated first. In order to prevent soil collapse, the foundation pit needs to be reinforced, among which the safety of deep foundation pit is particularly important. If the supporting structure of deep foundation pit is unqualified or non-standard, it will cause serious consequences. Therefore, the quality and safety of deep foundation pit support structure should attract the attention of relevant construction personnel. According to different geological conditions, formulate appropriate support schemes, and apply the existing construction technology to make the foundation pit stable and safe, which lays a foundation for later construction projects.展开更多
In order to scientifically and quantitatively evaluate the stability of the perim-eter rock of the roadway in Baliancheng coal mine,this paper adopts a com prehensive method of field measurement,theoretical analysis,l...In order to scientifically and quantitatively evaluate the stability of the perim-eter rock of the roadway in Baliancheng coal mine,this paper adopts a com prehensive method of field measurement,theoretical analysis,laboratory test and numerical simulation to study the geological and structural characteristics of the perimeter rock of the roadway,the physical and mechanical properties of the perimeter rock as well as the state of the perimeter rock stress,and pro-poses a comprehensive index method for classifying the stability of the perim eter rock of the roadway.The research results show that:the top plate of 18 coal roadway is mainly medium-hard rock composite top plate of siltstone,medium-grained sandstone and coarse sandstone,and the bottom plate is softmediumhard rock composite bottom plate of medium-grained sandstone,fine-grained sandstone and coarse-grained sandstone,the coefficient of coal seam solidity is 1.28,the fissures of perimeter rock are moderately developed,the influence coefficient of mining is 2.71,and the ratio of the maximal hori zontal principal stress to the vertical stress is 1.90,the stability grade of 18 coal roadway perimeter rock belongs to medium stable perimeter rock,after adopt-ing the optimized support scheme,the overall deformation of the roadway is relatively reduced compared with the original support scheme,and the support effect of the roadway perimeter rock is good.展开更多
基金This work was partially supported by the National Natural Science Foundation of China under Grant No. 69990540.
文摘In this letter, we analyze the drawback of tail-dropping contention resolution in optical burst switched networks. Once contention occurs, we adopt modified head-dropping policy to resolve contention. This policy drops the head of the contending burst only if the overlapping region of the two bursts is less than the whole contending burst size, otherwise drops the whole contending burst. In order to have a better support of differentiated service, a new burst assembly policy, namely, Priority-based proportional mixed burst assembly, is proposed. Simulation results show that the proposed scheme performs very well in terms of performance metrics such as the times of contention and packet loss probability.
基金Supported by Project of the National High Technology Research and Development Program of China(No.2003AA602250)
文摘Based on the design principles of economic rationality and safety,multiple-pivot pile anchorage approach was used as the supporting engineering of a tall building with a deep foundation ditch.The designs,such as anchor arm,single pile and the whole,were set up in accordance with the calculations of the internal force from the equivalent beam and Yamagata Kunio methods.Moreover,the rationality of the design was estimated using the stability checks.FLAC3D was used for calculating the accuracy of the design.Using FLAC3D to simulating ditch cutting and supporting processes can obtain the equivalent results as the theory analysis in the displacement of ditch surrounding wall,the stress field and stress distribution.
文摘University College Dublin(UCD) has implemented the Output-Based Research Support Scheme(OBRSS) since 2016. Adapted from the Norwegian model, the OBRSS awards individual academic staff using a points system based on the number of publications and doctoral students. This article describes the design and implementation processes of the OBRSS, including the creation of the ranked publication list and points system and infrastructure requirements. Some results of the OBRSS will be presented, focusing on the coverage of publications reported in the OBRSS ranked publication list and Scopus, as well as information about spending patterns. Challenges such as the evaluation of the OBRSS in terms of fairness, transparency, and effectiveness will also be discussed.
文摘As we all know, the most important factor for a high-rise building to stand is to lay a good foundation and make it safe and reliable. Before the construction of foundation, the foundation should be excavated first. In order to prevent soil collapse, the foundation pit needs to be reinforced, among which the safety of deep foundation pit is particularly important. If the supporting structure of deep foundation pit is unqualified or non-standard, it will cause serious consequences. Therefore, the quality and safety of deep foundation pit support structure should attract the attention of relevant construction personnel. According to different geological conditions, formulate appropriate support schemes, and apply the existing construction technology to make the foundation pit stable and safe, which lays a foundation for later construction projects.
文摘In order to scientifically and quantitatively evaluate the stability of the perim-eter rock of the roadway in Baliancheng coal mine,this paper adopts a com prehensive method of field measurement,theoretical analysis,laboratory test and numerical simulation to study the geological and structural characteristics of the perimeter rock of the roadway,the physical and mechanical properties of the perimeter rock as well as the state of the perimeter rock stress,and pro-poses a comprehensive index method for classifying the stability of the perim eter rock of the roadway.The research results show that:the top plate of 18 coal roadway is mainly medium-hard rock composite top plate of siltstone,medium-grained sandstone and coarse sandstone,and the bottom plate is softmediumhard rock composite bottom plate of medium-grained sandstone,fine-grained sandstone and coarse-grained sandstone,the coefficient of coal seam solidity is 1.28,the fissures of perimeter rock are moderately developed,the influence coefficient of mining is 2.71,and the ratio of the maximal hori zontal principal stress to the vertical stress is 1.90,the stability grade of 18 coal roadway perimeter rock belongs to medium stable perimeter rock,after adopt-ing the optimized support scheme,the overall deformation of the roadway is relatively reduced compared with the original support scheme,and the support effect of the roadway perimeter rock is good.
