Location Privacy Protection Mechanisms in Location-Sharing Service

Fei Xu,Jingsha He,Jinqiao Shi,Jing Xu,Yuqiang Zhang 보안공학연구지원센터 2012 International Journal of Multimedia and Ubiquitous Vol.7 No.2

A Cluster-Based Countermeasure against MAC Layer Attacks in IEEE 802.11 MANETs

Shi, Fei,Liu, Wei Jie,Jin, Dong Xu,Song, Joo Seok Trans Tech Publications, Ltd. 2013 Applied mechanics and materials Vol.284 No.-

<P>MANETs become a considerable interest nowadays. However, these types of networks are vulnerable to a large group of attacks, e.g., MAC layer attacks. Most of the previous researches related to security issues focus on detection of misbehaviors after it occurred. We propose a new way of thinking to evade occurrence of misbehaviors. A novel clustering algorithm is presented using analytic hierarchy process to elect clusterhead. Afterwards, the clusterhead is required to assign backoff values to originators in its transmission range, which are also the members in the corresponding cluster, rather than permitting the originators to choose backoff values. Meanwhile, the elected clusterhead also monitors whether originators obey the backoff values. With the proposed scheme, the misuse of the backoff in MAC layer in 802.11 DCF can be prevented.</P>

Moth-Flame Optimization-Based Maximum Power Point Tracking for Photovoltaic Systems Under Partial Shading Conditions

Shi, Ji-Ying,Zhang, Deng-Yu,Xue, Fei,Li, Ya-Jing,Qiao, Wen,Yang, Wen-Jing,Xu, Yi-Ming,Yang, Ting The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

This paper presents a moth-flame optimization (MFO)-based maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The MFO algorithm is a new optimization method that exhibits satisfactory performance in terms of exploration, exploitation, local optima avoidance, and convergence. Therefore, the MFO algorithm is quite suitable for solving multiple peaks of PV systems under partial shading conditions (PSCs). The proposed MFO-MPPT is compared with four MPPT algorithms, namely the perturb and observe (P&O)-MPPT, incremental conductance (INC)-MPPT, particle swarm optimization (PSO)-MPPT and whale optimization algorithm (WOA)-MPPT. Simulation and experiment results demonstrate that the proposed algorithm can extract the global maximum power point (MPP) with greater tracking speed and accuracy under various conditions.

Naringin and Naringenin Relax Rat Tracheal Smooth by Regulating BKCa Activation

Rui Shi,Jia-Wen Xu,Zi-Ting Xiao,Ruo-Fei Chen,Yi-Lin Zhang,Jia-Bi Lin,Ke-Ling Cheng,Gu-Yi Wei,Pei-Bo Li,Wen-Liang Zhou,Wei-Wei Su 한국식품영양과학회 2019 Journal of medicinal food Vol.22 No.9

Naringin and its aglycone, naringenin, occur naturally in our regular diet and traditional Chinese medicines. This study aimed to detect an effective therapeutic approach for cough variant asthma (CVA) through evaluating the relaxant effect of these two bioactive herbal monomers as antitussive and antiasthmatic on rat tracheal smooth muscle. The relaxant effect was determined by measuring muscular tension with a mechanical recording system in rat tracheal rings. Cytosolic Ca2+ concentration was measured using a confocal imaging system in primary cultured tracheal smooth muscle cells. In rat tracheal rings, addition of both naringin and naringenin could concentration dependently relax carbachol (CCh)-evoked tonic contraction. This epithelium-independent relaxation could be suppressed by BaCl2, tetraethylammonium, and iberiotoxin (IbTX), but not by glibenclamide. After stimulating primary cultured tracheal smooth muscle cells by CCh or high KCl, the intracellular Ca2+ increase could be inhibited by both naringin and naringenin, respectively. This reaction was also suppressed by IbTX. These results demonstrate that both naringin and naringenin can relax tracheal smooth muscle through opening big conductance Ca2+-activated K+ channel, which mediates plasma membrane hyperpolarization and reduces Ca2+ influx. Our data indicate a potentially effective therapeutic approach of naringin and naringenin for CVA.

Neutropenia during the First Cycle of Induction Chemotherapy Is Prognostic for Poor Survival in Locoregionally Advanced Nasopharyngeal Carcinoma: A Real-World Study in an Endemic Area

Cheng Xu,Shi-Ping Yang,Yuan Zhang,Ling-Long Tang,Guan-Qun Zhou,Xu Liu,Yan-Ping Mao,Rui Guo,Wen-Fei Li,Lei Chen,Ai-Hua Lin,Ying Sun,Jun Ma 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose The purpose of this study was to investigate the effect of neutropenia during the first cycle of induction chemotherapy (IC-1) on survival in locoregionally advanced nasopharyngeal carcinoma (LANPC). Materials and Methods Eligible patients (n=545) with LANPC receiving IC+concurrent chemoradiotherapy were included. Based on nadir neutrophil after IC-1, all patients were categorized into three groups: no/grade 1-2/grade 3-4 neutropenia. Five-year overall survival (OS) and disease-free survival (DFS) were compared between groups and subgroups stratified by IC regimen. We also explored the occurrence of IC-1–induced myelosuppression events and the minimal value of post-treatment neutrophil-to-lymphocyte ratio (post-NLRmin). Univariate/multivariate analyses were performed to investigate the effect of IC-1–induced neutropenia, timing of neutropenia, number of myelosuppression events, and high post-NLRmin on OS/DFS. Results Grade 1-2/grade 3-4 neutropenia were associated with poorer OS/DFS than no neutropenia (all p < 0.05); OS/DFS were not significantly different between patients experiencing grade 1-2 vs. 3-4 neutropenia. Neutropenia had no significant effect on OS/DFS in patients receiving docetaxel–cisplatin–5-fluorouracil (TPF). Grade 1-2 (grade 3-4) neutropenia negatively influenced OS/DFS in patients receiving cisplatin–5-fluorouracil (PF) (PF and docetaxel– cisplatin [TP]; all p < 0.05). Neutropenia, two/three myelosuppression events, and high post-NLRmin ( 1.33) was most frequent on days 5-10, second and third week of IC-1, respectively. After adjustment for covariates, IC-1–induced neutropenia, two/three myelosuppression events, and post-NLRmin  1.33 were validated as negative predictors of OS/DFS (all p < 0.05); timing of neutropenia had no significant effect. Conclusion Occurrence of neutropenia, number of myelosuppression events, and high post-NLRmin during PF/TP IC-1 have prognostic value for poor survival in LANPC.

Damage and stiffness research on steel shape steel fiber reinforced concrete composite beams

Chao Xu,Kai Wu,Ping zhou Cao,Shi qi Lin,Teng fei Xu 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.6

In this work, an experimental research has been performed on Steel Fiber-Steel Reinforced Concrete (SFSRC)specimens subjected to four-point bending tests to evaluate the feasibility of mutual replacement of steel fibers and conventional reinforcement through studying failure modes, load-deflection curves, stiffness of characteristic points, stiffness degradation curves and damage analysis. The variables considered in this experiment included steel fiber volume percentage with and without conventional reinforcements (stirrups or steel fibers) with shear span depth ratios of S/D=2.5 and 3.5. Experimental results revealed that increasing the volume percentage of steel fiber decreased the creation and propagation of shear and bond cracks, just like shortening the stirrups spacing. Higher crack resistance and suturing ability of steel fiber can improve the stability of its bearing capacity. Both steel fibers and stirrups improved the stiffness and damage resistance of specimens where stirrups played an essential role and therefore, the influence of steel fibers was greatly weakened. Increasing S/D ratio also weakened the effect of steel fibers. An equation was derived to calculate the bending stiffness of SFSRC specimens, which was used to determine mid span deflection; the accuracy of the proposed equation was proved by comparing predicted and experimental results.

Metabolomic analysis of biochemical changes in the tissue and urine of proteoglycan-induced spondylitis in mice after treatment with moxibustion

Xiao Xu,Ya-Nan Shi,Rong-Yun Wang,Cai-Yan Ding,Xiao Zhou,Yu-Fei Zhang,Zhi-Ling Sun,Zhi-Qin Sun,Qiu-Hua Sun 한국한의학연구원 2021 Integrative Medicine Research Vol.10 No.1

Background: Moxibustion is widely used in East Asian countries to manage the symptom of rheumatic diseases. The aim of this study was to identify potential metabolic profiles of moxibustion on relieving ankylosing spondylitis (AS) mice through UHPLC-Q-TOF/MS metabolomic study. Methods: Thirty-two female Balb/c mice were randomized into healthy control (HC), AS model, moxibustion at acupuncture points (MA) in AS model, and moxibustion at non-acupuncture points (MNA) AS model groups. Moxibustion was administered daily at GV4, bilateral BL23 and bilateral ST36 acupuncture points for four weeks in the MA group. The overall health status, the thickness of hind paws and the tissue concentrations of IL-1β, PGE2, IL-6 and TNF-α were assessed. The UHPLC-Q-TOF/MS was used to explore the perturbations of endogenous metabolites in tissue and urine of AS model mice intervened by moxibustion. Results: Compared with the AS group, the overall health status was significantly improved after 4-week moxibustion intervention (p < 0.05). The results also showed that MA significantly reduced the levels of paw thickness and decreased the levels of four cytokines in the tissue (p < 0.01). Thirty-seven endogenous metabolites identified by the OPLS-DA were considered to be contributing to therapeutic effects of moxibustion. Moreover, metabolic pathway analysis further revealed that the identified metabolites were mainly involved in TCA cycle, Lipid metabolism, Amino Acid metabolism, Intestinal flora metabolism and Purine metabolism. Conclusions: UHPLC-Q-TOF/MS based metabolomics approach, as a novel and powerful tool, can help us to gain the insights into potential mechanisms of action of moxibustion for AS.

Fibulin2: a negative regulator of BMSC osteogenic differentiation in infected bone fracture healing

Li Shi-Dan,Xing Wei,Wang Shao-Chuan,Li You-Bin,Jiang Hao,Zheng Han-Xuan,Li Xiao-Ming,Yang Jing,Guo De-Bin,Xie Xiao-Yu,Jiang Ren-Qing,Fan Chao,Li Lei,Xu Xiang,Fei Jun 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Bone fracture remains a common occurrence, with a population-weighted incidence of approximately 3.21 per 1000. In addition, approximately 2% to 50% of patients with skeletal fractures will develop an infection, one of the causes of disordered bone healing. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) plays a key role in disordered bone repair. However, the specific mechanisms underlying BMSC dysfunction caused by bone infection are largely unknown. In this study, we discovered that Fibulin2 expression was upregulated in infected bone tissues and that BMSCs were the source of infection-induced Fibulin2. Importantly, Fibulin2 knockout accelerated mineralized bone formation during skeletal development and inhibited inflammatory bone resorption. We demonstrated that Fibulin2 suppressed BMSC osteogenic differentiation by binding to Notch2 and inactivating the Notch2 signaling pathway. Moreover, Fibulin2 knockdown restored Notch2 pathway activation and promoted BMSC osteogenesis; these outcomes were abolished by DAPT, a Notch inhibitor. Furthermore, transplanted Fibulin2 knockdown BMSCs displayed better bone repair potential in vivo. Altogether, Fibulin2 is a negative regulator of BMSC osteogenic differentiation that inhibits osteogenesis by inactivating the Notch2 signaling pathway in infected bone.

Design optimization and development of SMC composite tray

Cun-fei Wang,Zeng-fu Yang,Chengwang Shi,Xiaodong Li,Xu-feng Zhang 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.2

In the engineering application, trays are easy to break down to result in anchorage failure in the composite anchoring systems. Therefore, the research carried out the force analysis with mechanics of materials to observe the main stress concentration anddeformation of the tray. From the findings of the force analysis, the structure and key parameters of the tray were optimizedwith reference of the existing tray design. Besides, the study turns to the finite element software to simulate and analyze thetray. The results manifest that tray failure during the support mainly results from the expansion and deformation of the taperhole squeezed by the nut, which causes the tray taper hole to rupture and crackle extend, thus leading to its crack. What’smore, the tray breaks for the compression of the tray edge by the surrounding rock. The maximum deformation at the largeend of the optimized tray tapered hole was reduced from 33.8 mm to 4.7 mm, approximately 86% with the shear stress reducedfrom 781.67 Mpa to 258.83 Mpa, about 66.8%. Using Sheet Molding Compound (SMC) to mould trays with new structure andconducting the test of tray bearing capacity, it can be found that its bearing capacity is up to 250 KN. After the taper hole ofthe tray is locally strengthened, its bearing capacity is increased to 304 KN.

Moth-Flame Optimization-Based Maximum Power Point Tracking for Photovoltaic Systems Under Partial Shading Conditions

Ji-Ying Shi,Deng-Yu Zhang,Fei Xue,Ya-Jing Li,Wen Qiao,Wen-Jing Yang,Yi-Ming Xu,Ting Yang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

This paper presents a moth-flame optimization (MFO)-based maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The MFO algorithm is a new optimization method that exhibits satisfactory performance in terms of exploration, exploitation, local optima avoidance, and convergence. Therefore, the MFO algorithm is quite suitable for solving multiple peaks of PV systems under partial shading conditions (PSCs). The proposed MFO-MPPT is compared with four MPPT algorithms, namely the perturb and observe (P&O)-MPPT, incremental conductance (INC)-MPPT, particle swarm optimization (PSO)-MPPT and whale optimization algorithm (WOA)-MPPT. Simulation and experiment results demonstrate that the proposed algorithm can extract the global maximum power point (MPP) with greater tracking speed and accuracy under various conditions.