Multibeam Satellite Frequency/Time Duality Study and Capacity Optimization

Lei, Jiang,Vazquez-Castro, Maria Angeles The Korea Institute of Information and Commucation 2011 Journal of communications and networks Vol.13 No.5

In this paper, we investigate two new candidate transmission schemes, non-orthogonal frequency reuse (NOFR) and beam-hopping (BH). They operate in different domains (frequency and time/space, respectively), and we want to know which domain shows overall best performance. We propose a novel formulation of the signal-to-interference plus noise ratio (SINR) which allows us to prove the frequency/time duality of these schemes. Further, we propose two novel capacity optimization approaches assuming per-beam SINR constraints in order to use the satellite resources (e.g., power and bandwidth) more efficiently. Moreover, we develop a general methodology to include technological constraints due to realistic implementations, and obtain the main factors that prevent the two technologies dual of each other in practice, and formulate the technological gap between them. The Shannon capacity (upper bound) and current state-of-the-art coding and modulations are analyzed in order to quantify the gap and to evaluate the performance of the two candidate schemes. Simulation results show significant improvements in terms of power gain, spectral efficiency and traffic matching ratio when comparing with conventional systems, which are designed based on uniform bandwidth and power allocation. The results also show that BH system turns out to show a less complex design and performs better than NOFR system specially for non-real time services.

Multibeam Satellite Frequency/Time Duality Study and Capacity Optimization

Jiang Lei,María Ángeles Vázquez-Castro 한국통신학회 2011 Journal of communications and networks Vol.13 No.5

In this paper, we investigate two new candidate transmission schemes, non-orthogonal frequency reuse (NOFR) and beamhopping (BH). They operate in different domains (frequency and time/space, respectively), and we want to know which domain shows overall best performance. We propose a novel formulation of the signal-to-interference plus noise ratio (SINR) which allows us to prove the frequency/time duality of these schemes. Further,we propose two novel capacity optimization approaches assuming per-beam SINR constraints in order to use the satellite resources (e.g., power and bandwidth)more efficiently.Moreover, we develop a general methodology to include technological constraints due to realistic implementations, and obtain the main factors that prevent the two technologies dual of each other in practice, and formulate the technological gap between them. The Shannon capacity (upper bound) and current state-of-the-art coding and modulations are analyzed in order to quantify the gap and to evaluate the performance of the two candidate schemes. Simulation results show significant improvements in terms of power gain, spectral efficiency and traffic matching ratio when comparing with conventional systems,which are designed based on uniform bandwidth and power allocation. The results also show that BH system turns out to show a less complex design and performs better than NOFR system specially for non-real time services.

Study on the micro-scale simulation of wind field over complex terrain by RAMS/FLUENT modeling system

Lei Li,Li-Jie Zhang,Ning Zhang,Fei Hu,Yin Jiang,Chun-Yi Xuan,Wei-Mei Jiang 한국풍공학회 2010 Wind and Structures, An International Journal (WAS Vol.13 No.6

A meteorological model, RAMS, and a commercial computational fluid dynamics (CFD) model, FLUENT are combined as a one-way off-line nested modeling system, namely, RAMS/FLUENT system. The system is experimentally applied in the wind simulation over a complex terrain, with which numerical simulations of wind field over Foyeding weather station located in the northwest mountainous area of Beijing metropolis are performed. The results show that the method of combining a meteorological model and a CFD model as a modeling system is reasonable. In RAMS/FLUENT system, more realistic boundary conditions are provided for FLUENT rather than idealized vertical wind profiles, and the finite volume method (FVM) of FLUENT ensures the capability of the modeling system on describing complex terrain in the simulation. Thus, RAMS/FLUENT can provide fine-scale realistic wind data over complex terrains.

D-InSAR Monitoring Method of Mining Subsidence Based on Boltzmann and Its Application in Building Mining Damage Assessment

Lei Wang,Chaoqun Teng,Kegui Jiang,Chuang Jiang,Shangjun Zhu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.1

Monitoring and predicting mining area subsidence caused by coal mining help effectively control geological disasters. Information regarding small surface deformations can be obtained using a differential interferometric synthetic aperture radar (D-InSAR), which exhibits high monitoring accuracy and can cover large areas; thus, D-InSAR are being applied for mining area settlement monitoring. However, mining areas are prone to large gradient deformations in short durations; obtaining information regarding such deformations is outside the scope of D-InSAR monitoring. To adapt to the characteristics of D-InSAR monitoring, this study selected a Boltzmann function model with a slow boundary convergence rate to address the problem of probabilistic integration methods exhibiting a high boundary convergence rate. The three-dimensional surface deformation of the mining area can be accurately obtained. According to the projection relationship between D-InSAR line of sight (LOS) directional deformation, subsidence, and horizontal movement, a D-InSAR monitoring equation for mining subsidence assisted by Boltzmann is derived. This equation is combined with the shuffled frog leaping algorithm (SFLA) to obtain the parameters to be estimated from the equation. The D-InSAR LOS deformation information of the 13121 working face in the Huainan mining area was obtained from July 14 to October 30, 2019. The proposed method was then used to obtain the predicted parameters of the working face under insufficient mining. The predicted parameters of mining subsidence were calculated to obtain the predicted parameters when it was fully mined. Then, the revised parameters were used to predict the subsidence and horizontal movement of the mining area and compared with the actual leveling observations. The results show that the mean square error of predicted subsidence is 97.1 mm, which is about 3.09% of the maximum subsidence value; the mean square error of predicted horizontal movement is 46.1 mm, which is about 4.1% of the maximum horizontal movement value. The predicted results of the aforementioned method were used to analyze the damage to the buildings above the working face and determine the damage level of the buildings to provide a reference for the demolition and maintenance of the Zhaimiao village.

Effect of Embelin on TRAIL Receptor 2 mAb-induced Apoptosis of TRAIL-resistant A549 Non-small Cell Lung Cancer Cells

Jiang, Lei,Hao, Jin-Li,Jin, Mu-Lan,Zhang, Yun-Gang,Wei, Ping Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Introduction: Some non-small cell lung cancer (NSCLC) tumor cells are insensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) -based therapy. This study was conducted to examine the effect of embelin on the sensitivity of the A549 NSCLC cell line to TRAIL receptor2 (TRAILR2) monoclonal antibodies and to investigate the potential mechanisms. Materials and Methods: A549 cells were treated with embelin, TRAILR2 mAb or a combination of both. Cell viability was measured using ATPlite assay and apoptosis rates were determined by flow cytometry with AnnexinV-FITC and propidium iodide staining, with the expression levels of proteins analyzed by Western blotting. Results: The cell survival rate of separate treatments with 100 ng/ml TRAILR2 antibody or 25 uM embelin were $81.5{\pm}1.57%$ and $61.7{\pm}2.84%$, respectively. Their combined use markedly decreased cell viability in A549 cells to $28.1{\pm}1.97%$ (P<0.05). The general caspase inhibitor Z-VAD-FMK could inhibit the embelin-enhanced sensitivity of A549 cells to TRAILR2 mAb ($75.97{\pm}3.17%$)(P<0.05). Both flow cytometry and cell morphological analysis showed that embelin was able to increase TRAIL-induced apoptosis in A549 cells. Combined treatment with embelin and TRAILR2 mAb augmented the activation of initiator caspases and effector caspase. In addition, A549 cells showed increasing levels of TRAILR2 protein and decreasing levels of Bcl-2, survivin and c-FLIP following the treatment with embelin+TRAILR2 mAb. Conclusions: Embelin could enhance TRAIL-induced apoptosis in A549 cells. The synergistic effect of the combination treatment might be due to modulation of multiple components in the TRAIL receptor-mediated apoptotic signaling pathway, including TRAILR2, XIAP, survivin, Bcl-2 and c-FLIP.

Comparison of landslide susceptibility maps using random forest and multivariate adaptive regression spline models in combination with catchment map units

Lei Chu,Liang-Jie Wang,Jiang Jiang,Xia Liu,Kazuhide Sawada,Jinchi Zhang 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.2

Landslide susceptibility mapping (LSM) is a critical tool for mitigating the damages caused by geologic disasters. The selection of map units and mathematical models greatly affects the efficiency of LSM. To obtain the most appropriate combination of map units and mathematical models, four scales of catchment map units (CMUs) were analyzed and random forest (RF) and multivariate adaptive regression spline (MARSpline) models were applied in Gero City, Japan. The percentage of correctly identified landslides and the areas under the relative operating characteristic (ROC) curve were used to evaluate the model performances. The results indicate that the RF model had higher prediction accuracy than the MARSpline model, especially when the size of the CMU was 0.09 km2. A relatively high percentage of landslides fell into the high and very high landslide susceptibility classes (73%) and the lowest percentage of landslides fell into the very low landslide susceptibility classes (0.82%). The prediction-area (P-A) plots indicated that the prediction rates were higher for the RF model than the MARSpline model. The results of this study also suggest that the model accuracy can be increased if the appropriate CMU size is used. Therefore, the potential benefits of using the RF model in combination with the appropriate CMU size should be further explored using additional landslide-conditioning factors and other models.

The Input-output’s Control Strategy of the Fashion Company

Lei Jiang,Shouzhong Hu,Bingqiang Tian 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.1

This paper deals with the problems of control strategy of the fashion company. The input-output model is founded based on the singular stochastic dynamic Leontief input-output model. A new mathematic method is applied to study the singular systems without converting them into general linear systems. The parameter uncertainties are considered and are assumed to be time-invariant and Markovian jumping. A new stability criterion for singular system is given to ensure the robust stability of singular input-output model in terms of linear matrix inequality. Finally, the corresponding computer control algorithm is provided.

Predictors of Cerebrospinal Fluid Leak Following Dural Repair in Spinal Intradural Surgery

Lei Jiang,Alexandru Budu,Muhammad Shuaib Khan,Edward Goacher,Angelos Kolias,Rikin Trivedi,Jibin Francis 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: We aim to compare the effectiveness of dural closure techniques in preventing cerebrospinal fluid (CSF) leaks following surgery for intradural lesions and seek to identify additional factors associated with CSF leaks. Surgical management of spinal intradural lesions involves durotomy which requires a robust repair to prevent postoperative CSF leakage. The ideal method of dural closure and the efficacy of sealants has not been established in literature. Methods: We performed a retrospective analysis of all intradural spinal cases performed at a tertiary spine centre from 1 April 2015 to 29 January 2020 and collected data on patient bio-profile, dural repair technique, and CSF leak rates. Multivariate analysis was performed to identify predictors for postoperative CSF leak. Results: A total of 169 cases were reported during the study period. There were 15 cases in which postoperative CSF leak was reported (8.87%). Multivariate analysis demonstrated that patient age (odds ratio [OR], 0.942; 95% confidence interval [CI], 0.891–0.996), surgical indication listed in the “others” category (OR, 44.608; 95% CI, 1.706–166.290) and dural closure with suture, sealant and patch (OR, 22.235; 95% CI, 2.578–191.798) were factors associated with CSF leak. Postoperative CSF leak was associated with the risk of surgical site infection with a likelihood ratio of 8.704 (χ² (1) = 14.633, p < 0.001). Conclusion: Identifying predictors for CSF leaks can assist in the counselling of patients with regard to surgical risk and expected postoperative recovery.

Fast Recovery Routing Algorithm for Software Defined Network based Operationally Responsive Space Satellite Networks

( Lei Jiang ),( Jing Feng ),( Ye Shen ),( Xinli Xiong ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.7

An emerging satellite technology, Operationally Responsive Space (ORS) is expected to provide a fast and flexible solution for emergency response, such as target tracking, dense earth observation, communicate relaying and so on. To realize large distance transmission, we propose the use of available relay satellites as relay nodes. Accordingly, we apply software defined network (SDN) technology to ORS networks. We additionally propose a satellite network architecture refered to as the SDN-based ORS-Satellite (Sat) networking scheme (SDOS). To overcome the issures of node failures and dynamic topology changes of satellite networks, we combine centralized and distributed routing mechanisms and propose a fast recovery routing algorithm (FRA) for SDOS. In this routing method, we use centralized routing as the base mode.The distributed opportunistic routing starts when node failures or congestion occur. The performance of the proposed routing method was validated through extensive computer simulations.The results demonstrate that the method is effective in terms of resoving low end-to-end delay, jitter and packet drops.

Preparation and Characterization of a Novel Hyperbranched Poly(aryl ether ketone) Terminated with Cobalt Phthalocyanine to be Used for Oxidative Decomposition of 2,4,6-Trichlorophenol

Lei Lei,Yunhe Zhang,Xiujie Li,Jianxin Mu,Guibin Wang,Zhenhua Jiang,Shuling Zhang 한국고분자학회 2010 Macromolecular Research Vol.18 No.4

A novel hyperbranched poly(aryl ether ketone) terminated with cobalt phthalocyanine (CoPc-T-HPAEK)was prepared using 1,3,5-tris[4-(4-fluorobenzoyl) phenoxy] benzene (B3), as a ‘core’ molecule, 4,4'-(hexafluoroisopropylidene)diphenol (6F-BPA) as an A2 monomer, and cobalt phthalocyanine as an end-capping reagent. CoPc-THPAEK showed good solubility, thermal stability and catalytic activity in the oxidative decomposition of 2,4,6-trichlorophenol (TCP) under H2O2 or KHSO5. Moreover, the oxidative effect of KHSO5 was superior to that of H2O2,and the catalytic activity of CoPc-T-HPAEK was much higher than that of linear poly(aryl ether ketone) terminated with cobalt phthalocyanine (CoPc-T-LPAEK) and linear poly(aryl ether ketone) with a cobalt phthalocyanine pendant unit (CoPc-S-LPAEK).