The exhaust smoke dispersion for a generic frigate is investigated numerically through the numerical solution of the governing fluid flow, energy, species and turbulence equations. The main objective of this work is t...The exhaust smoke dispersion for a generic frigate is investigated numerically through the numerical solution of the governing fluid flow, energy, species and turbulence equations. The main objective of this work is to obtain the effects of the yaw angle velocity ratio and buoyancy on the dispersion of the exhaust smoke The numerical method is based on the fully conserved control-volume representation of the fully elliptic Navier-Stokes equations. Turbulence is modeled using a two-equation （k-ε） model The flow visualization tests using a 1/100 scale model of the frigate in the wind tunnel were also carried out to determine the exhaust plume path and to validatc the computational results. The results show that down wash phenomena occurs for the yaw angles between ψ=10° and 20°. The results with different exhaust gas temperatures show that the buoyancy effect increases with the increasing of the exhaust gas temperature. However, its effect on the plume rise is less significant in comparison with its momentum. A good agreement between the predictions and experiment results is obtained.展开更多
Moment invariants firstly introduced by M. K Hu in 1962, has some shortcomings. After counting a large number of statistical distribution information of Chinese characters,the authors put forward the concept of inform...Moment invariants firstly introduced by M. K Hu in 1962, has some shortcomings. After counting a large number of statistical distribution information of Chinese characters,the authors put forward the concept of information moments and demonstrate its invariance to translation,rotation and scaling.Also they perform the experiment in which information moments compared with moment invaiants for the effects of similar Chinese characters and font recognition.At last they show the recognition rate of 88% by information moments,with 70% by moment inariants.展开更多
OBJECTIVE To evaluate the efficacy and adverse effects ofgemcitabine versus pegylated liposomal doxorubicin in patientswith progressive or recurrent ovarian cancer.METHODS We conducted a systematic literature search t...OBJECTIVE To evaluate the efficacy and adverse effects ofgemcitabine versus pegylated liposomal doxorubicin in patientswith progressive or recurrent ovarian cancer.METHODS We conducted a systematic literature search toidentify all randomized controlled trials comparing gemcitabineand pegylated liposomal doxorubicin for progressive orrecurrent ovarian cancer. Trial data were reviewed and extractedindependently by 2 reviewers. We evaluated the quality of theincluded studies using the Handbook 5.0 recommend standardsand then analyzed data by Cochrane Collaboration's RevMan 5.0.RESULTS Two trials which included a total of 348 patients wereanalyzed. The results of meta-analysis showed that gemcitabineimproved disease control rates significantly better than pegylatedliposomal doxorubicin. A greater number of patients receivinggemcitabine experienced neutropenia compared with patientsreceiving pegylated liposomal doxorubicin; however, hand-footsyndrome and mucositis were more severe in patients receivingpegylated liposomal doxorubicin.CONCLUSION Gemcitabine provided a limited advantagecompared with pegylated liposomal doxorubicin. There existsan urgent need for more high-quality, multicenter, adequaterandomized, controlled clinical trials for comparing gemcitabinewith pegylated liposomal doxorubicin in patients withprogressive/recurrent ovarian cancer.展开更多
In the context of this paper, a small scale, medium precision, stabilized pan/tilt platform is developed as a prototype, which is used to compare various stabilization algorithms experimentally. The overall performanc...In the context of this paper, a small scale, medium precision, stabilized pan/tilt platform is developed as a prototype, which is used to compare various stabilization algorithms experimentally. The overall performance of the system depends on rigid body dynamics, structural dynamics, servo control loops, stabilization control algorithm, sensor fusion algorithm and sensory feedback such as from the IMU （inertial measurement unit）. In the case that the response bandwidth of the overall system is high enough, the same hardware can also achieve active vibration isolation. All of these design aspects are investigated in the paper via numerical models and with their experimental verification.展开更多
基金the financial support received from the Scientific Research Projects Office of Istanbul Technical University,stanbul, Turkey for the project titled as ‘Numerical and Experimental Investigation of Exhaust Smoke Dispersion for Naval Ships’
文摘The exhaust smoke dispersion for a generic frigate is investigated numerically through the numerical solution of the governing fluid flow, energy, species and turbulence equations. The main objective of this work is to obtain the effects of the yaw angle velocity ratio and buoyancy on the dispersion of the exhaust smoke The numerical method is based on the fully conserved control-volume representation of the fully elliptic Navier-Stokes equations. Turbulence is modeled using a two-equation （k-ε） model The flow visualization tests using a 1/100 scale model of the frigate in the wind tunnel were also carried out to determine the exhaust plume path and to validatc the computational results. The results show that down wash phenomena occurs for the yaw angles between ψ=10° and 20°. The results with different exhaust gas temperatures show that the buoyancy effect increases with the increasing of the exhaust gas temperature. However, its effect on the plume rise is less significant in comparison with its momentum. A good agreement between the predictions and experiment results is obtained.
基金supported by the Specical Fund of Taishan Scholar of Shandong Province
文摘Moment invariants firstly introduced by M. K Hu in 1962, has some shortcomings. After counting a large number of statistical distribution information of Chinese characters,the authors put forward the concept of information moments and demonstrate its invariance to translation,rotation and scaling.Also they perform the experiment in which information moments compared with moment invaiants for the effects of similar Chinese characters and font recognition.At last they show the recognition rate of 88% by information moments,with 70% by moment inariants.
文摘OBJECTIVE To evaluate the efficacy and adverse effects ofgemcitabine versus pegylated liposomal doxorubicin in patientswith progressive or recurrent ovarian cancer.METHODS We conducted a systematic literature search toidentify all randomized controlled trials comparing gemcitabineand pegylated liposomal doxorubicin for progressive orrecurrent ovarian cancer. Trial data were reviewed and extractedindependently by 2 reviewers. We evaluated the quality of theincluded studies using the Handbook 5.0 recommend standardsand then analyzed data by Cochrane Collaboration's RevMan 5.0.RESULTS Two trials which included a total of 348 patients wereanalyzed. The results of meta-analysis showed that gemcitabineimproved disease control rates significantly better than pegylatedliposomal doxorubicin. A greater number of patients receivinggemcitabine experienced neutropenia compared with patientsreceiving pegylated liposomal doxorubicin; however, hand-footsyndrome and mucositis were more severe in patients receivingpegylated liposomal doxorubicin.CONCLUSION Gemcitabine provided a limited advantagecompared with pegylated liposomal doxorubicin. There existsan urgent need for more high-quality, multicenter, adequaterandomized, controlled clinical trials for comparing gemcitabinewith pegylated liposomal doxorubicin in patients withprogressive/recurrent ovarian cancer.
文摘In the context of this paper, a small scale, medium precision, stabilized pan/tilt platform is developed as a prototype, which is used to compare various stabilization algorithms experimentally. The overall performance of the system depends on rigid body dynamics, structural dynamics, servo control loops, stabilization control algorithm, sensor fusion algorithm and sensory feedback such as from the IMU （inertial measurement unit）. In the case that the response bandwidth of the overall system is high enough, the same hardware can also achieve active vibration isolation. All of these design aspects are investigated in the paper via numerical models and with their experimental verification.
