빔 구조물의 손상평가를 위한 임피던스 기술의 응용

홍동표,홍용,왕고평,김병진,김영문,이재정,김재열 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

This paper presents a primary study for a new method of enhancing measurement using impedance analysis method, which is widely used for structure health monitoring. Many of skyscrapers, bridges, tunnels, which have been built up several years, and nearly reached their operating life due to aging crack, material deterioration, and so on. therefore, the health monitoring technique has obtained considerable attention. The goal of this research is to show basic information to evaluate structural health condition using piezoelectric sensors. The piezoelectric materials have various merits. It is easy to shape various forms and can be embedded on the materials more conveniently. Moreover, the excitation frequency can be changed and the piezoelectric sensors cost less. All these features make the piezoelectric-based system applicable to structural healthy monitoring. This work presents a study for the development of a practical and quantitative technique for assessment of the structural health condition by piezoelectric impedance-based technique associated with longitudinal wave propagation. To estimate the damage condition numerically, we suggest the evaluation method Cov (Covariance) and CC (Correlation Coefficient) in this paper.

City-Wide Smart Healthcare Appointment Systems Based on Cloud Data Virtualization PaaS

Ping He,Penghai Wang,Jiechun Gao,Bingyong Tang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.2

While the cloud computing benefits healthcare IT modernization, it introduces new challenges for data integration, which is crucial for information sharing, data mining and business intelligence applications. Data virtualization brings a new strategy and related technologies to cope with these challenges, particularly suitable for cloud data services and SaaS (Software-as-a-Service) applications. The paper discussed a unique architecture and related technologies to implement the data virtualization for cloud data. The paper also demonstrated how this technology can be used in the real-world applications, and a city-wide healthcare appointment system has been implemented for example.

Study on Fault Detection and Diagnosis of the Edge-Transmission Ball Mill System

Wang, Gao Ping,Hong, Yong,Hong, Dong Pyo,Yang, Sung Mo,Kim, Young Moon Trans Tech Publications, Ltd. 2007 Key Engineering Materials Vol.353-358 No.3

<P>Pieces of large-scale equipment such as a ball mill system are subjected to heavy and alternate loads under the worst working conditions, which result in higher fault rates. However, since such equipment exerts important functions to the economy and industry, it isn’t recommendable to halt production in order to detect the defects under unconfirmed faults. We explore a reliable and practical fault diagnosis scheme for the ball mill system that is widely used in the building material industry. With utilizing the signal acquisition and process system of vibration, the field testing and analysis are performed based on the violent vibration of an edge-transmission Φ3×11m ball mill system. The primary diagnosis that is based on the configuration of the transmission system and foundation stiffness is found, and a feasible resolution scheme is obtained, so that the optimal and economic reform scheme is determined. The detailed scheme has been adopted by the production industry. This study that is based on the fault diagnosis of the edgetransmission ball mill system has a comprehensive significance of theory and reality. This provides a larger basis for vibration inspection and fault diagnosis in building material industries.</P>

Quantitative Estimation of the Fastening Condition of a Bolt with Using Piezoceramic (PZT) Sensors

Wang, Gao Ping,Hong, Yong,Lee, Jae Jung,Hong, Dong Pyo,Kim, Young Moon,Kim, Jae Yeol Trans Tech Publications, Ltd. 2007 Key Engineering Materials Vol.353-358 No.3

<P>We present a study on the development of a practical and quantitative technique for the assessment of the structural health condition with using piezoceramic (PZT) sensors. The electroimpedance- based technique with the PZT patches is very sensitive for evaluation of the incipient and small damage in a high frequency range, and however the commonly traditional modal analysis method is effective only for considerably larger damages in low frequency range. The paper presents the performance of the performance of the electro-impedance-based technique in detecting and characterizing real-time damage on the specimen that is an aluminum plate fastened with bolts and nuts by different torques. By using the special arrangement of the PZT sensors, the required longitudinal wave is generated through the specimen. A large number of experiments are conducted and the different conditions of the specimen, i.e. the location of loosening bolts and the loosening extent of bolts are simulated, respectively. Since fixing and loosening the loosened bolt is controlled by a torque wrench, we can control exactly the experiment of the different torques. Compared with the simulated healthy condition, we can find whether or not there is a damage in the specimen with using an impedance analyzer with the PZT sensors. Several indices are discussed and used for assessing the different simulated damages. As for the location of bolt loosening, the RMSD is found to be the most appropriate index for numerical assessment and as well the RMSD shows strongly linear relationship for assessing the extent of the bolt loosening. The possibility of repeatability of the pristine condition signatures is also presented and the appropriate frequency range and interval are uniquely selected through large numbers of experiments. The analytical results strongly show the sensibility and reliability of the electro-impedance based technique.</P>

Complete ¹H-NMR and <SUP>13</SUP>C-NMR spectral assignment of five malonyl ginsenosides from the fresh flower buds of Panax ginseng

Yu-Shuai Wang,Yin-Ping Jin,Wei Gao,Sheng-Yuan Xiao,Yu-Wei Zhang,Pei-He Zheng,Jia Wang,Jun-Xia Liu,Cheng-He Sun,Ying-Ping Wang 고려인삼학회 2016 Journal of Ginseng Research Vol.40 No.3

Background: Ginsenosides are the major effective ingredients responsible for the pharmacological effects of ginseng. Malonyl ginsenosides are natural ginsenosides that contain a malonyl group attached to a glucose unit of the corresponding neutral ginsenosides. Methods: Medium-pressure liquid chromatography and semipreparative high-performance liquid chromatography were used to isolate purified compounds and their structures determined by extensive one-dimensional- and two-dimensional nuclear magnetic resonance (NMR) experiments. Results: A new saponin, namely malonyl-ginsenoside Re, was isolated from the fresh flower buds of Panax ginseng, along with malonyl-ginsenosides Rb1, Rb2, Rc, Rd. Some assignments for previously published ¹H- and <SUP>13</SUP>C-NMR spectra were found to be inaccurate. Conclusion: This study reports the complete NMR assignment of malonyl-ginsenoside Re, Rb₁, Rb₂, Rc, and Rd for the first time.

A Bidirectional Three-level DC-DC Converter with a Wide Voltage Conversion Range for Hybrid Energy Source Electric Vehicles

Ping Wang,Chendong Zhao,Yun Zhang,Jing Li,Yongping Gao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

Overexpression of Twist and Matrix Metalloproteinase-9 with Metastasis and Prognosis in Gastric Cancer

Gao, Xing-Hui,Yang, Xue-Qin,Wang, Bi-Cheng,Liu, Shao-Ping,Wang, Fu-Bing Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Objective: Twist, a basic helix-loop-helix transcription factor, plays a key role in the metastatic progression of human cancer. Matrix metalloproteinase (MMP)-9 is an endopeptidase that digests basement membrane type IV collagen, therefore being possibly related to tumor progression. It has been reported that Twist and matrix metalloproteinase-9 (MMP-9) are expressed in gastric cancers. However, the exact roles of Twist and MMP-9 in tumor metastasis and prognosis remain unclear. The aim of this study was to casts light on this question. Methods:Twist and MMP-9 expression in tissue sections of 37 gastric carcinomas was evaluated with immunohistochemistry. The staining results were compared with clinicopatholgic features and to patients' outcome. Results: Twist positive expression was significantly increased in gastric cancer cases with lymph node metastasis (P=0.023). But no correlations were found between MMP-9 overexpression and clinicopathologic features, such as recurrence, TNM stage, and lymph node metastasis. Overall survival (OS) was significantly correlated with recurrence, serosa invasion, TNM stages, distant metastasis, and MMP-9 (P=0.027, 0.021, 0.000, 0.024 and 0.036, respectively). Disease-free survival (DFS) was prominently related to recurrence location, serosa invasion and TNM stages (P=0.000, 0.038 and 0.003, respectively). In the Cox regression multivariate analysis, TNM stage, distant metastasis and MMP-9 were significantly associated with prognosis of gastric cancer (P=0.002, 0.019, and 0.032, respectively). Conclusions: This study showed Twist positive expression to be significantly correlated with lymph node metastasis in gastric cancer. MMP-9 overexpression is associated with OS, suggesting that MMP-9 is a prognostic indicator for survival in patients with gastric cancer.

Coupling Effect Analysis for Hybrid Piezoelectric and Electromagnetic Energy Harvesting from Random Vibrations

Ping Li,Shiqiao Gao,Huatong Cai,Huamin Wang 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

Through establishing the electroelastic model of hybrid piezoelectric(PE) and electromagnetic(EM) energy harvesting from randomvibrations, normalized expressions of mean amplitude, voltage, current, power and their spectral density (SD) are derived, and effectsof electromechanical coupling strength on harvester’s performances are studied by numerical calculation and experimental test. It isfound that the stronger coupling effect, the smaller amplitude and working space required, and the bigger mean voltage, current andpower output until up to their maximums. Furthermore, variation extent of mean voltage, current and power with the PE and EMload increasing varies with the coupling strength. Besides, coupling strength changes the SD distributing in frequency domain. In theweak coupling, maximal SD of voltage, current and power are at the natural frequency of harvester. However, with the coupling effectstrengthening, the frequency corresponding to peak spectral density is bigger than the natural frequency , and the 3dB bandwidth ofharvester is much larger accordingly; moreover, the bandwidth decreases with EM load increasing while it rises firstly and fall laterwith PE load increasing, which reaches the maximum at the optimal load. The analysis results can provide certain criteria for hybridpiezoelectric-electromagnetic energy harvester design.

Effect of PCL-b-PEG Oligomer Containing Ionic Elements on Phase Interfacial Properties and Aggregated Structure of PLA/PCL Blends

Ping Wang,Shang Gao,Xinliang Chen,Li Yang,Tian Cao,Bingyu Fan,Jin Liu,Xianhai Hu 한국고분자학회 2022 Macromolecular Research Vol.30 No.7

The polycaprolactone (PCL)-b-polyethylene glycol (PEG) oligomer (Oli) and its derivative containing ionic elements (ILs) were used as interfacial compatibilizers and regulators, and the polylactic acid (PLA)/PCL/Oli and PLA/PCL/ILs blends were prepared by solution blending. The effects of Oli and ILs on the phase interfacial properties, aggregated structure, crystallization and mechanical properties of PLA/PCL blends were systematically studied. The results show that the ILs with strong interfacial emulsification ability can improve the dispersion of PCL in PLA matrix, and enhance the two-phase interfacial adhesion. When the content of ILs is 5 %, ion clusters can form and alleviate the restricted crystallization of PCL, and promote the segment movement of PLA through the non-covalent bonding of ionic elements. So the crystallization ability of PLA and PCL improve simultaneously. ILs have a strong regulatory effect on the phase interfacial morphology and aggregated structure of PLA/PCL blends, and the PLA/PCL blends containing high content of 5 % ILs can significantly improve the mechanical properties of PLA/PCL blends.

Clinical Observation on Recombinant Human Endostatin Combined with Chemotherapy for Advanced Gastrointestinal Cancer

Gao, Shao-Rong,Li, Lu-Ming,Xia, Hai-Ping,Wang, Guang-Ming,Xu, Hong-Yan,Wang, Ai-Rong Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.9

Objective: To explore the clinical efficacy and toxic and side effects of recombinant human endostatin (rhendostatin/endostar) combined with chemotherapy in the treatment of advanced gastric cancer. Materials and Methods: A total of 70 patients with advanced gastrointestinal adenocarcioma confirmed by histopathology and/or cytological examination were divided into group A (37 patients) and group B (33 patients). Patients in group A were given intravenous drip of 15 mg endostar added into 500 mL normal saline, once every other day until the cessation of chemotherapy or patients' maximal tolerance to chemotherapy. Patients in group B received chemotherapy alone. Two groups selected the same chemotherapy regimens. FOLFIRI scheme: 90-min intravenous drip of $180mg/m^2$ irinotecan, intravenous drip of $200mg/m^2$ calcium folinate (CF) and $400mg/m^2$ 5-fluorouracil (5-Fu) on d1, and continuous intravenous pumping of 2 $400mg/m^2$ 5-Fu for 46 h. FOLFOX4 scheme: intravenous injection of $85mg/m^2$ oxaliplatin (L-OHP), $200mg/m^2$ calcium folinate (CF) and $400mg/m^2$ 5-FU on d1 for 2 h, and then continuous intravenous pumping of 2 $400mg/m^2$ 5-Fu for 46 h. XELOX scheme: oral administration of 1 $500mg/m^2$ xeloda (or tegafur 50~60 mg) in twice during d1~14 and intravenous drip of $135mg/m^2$ L-OHP on d1 for 2 h. The modified FOLFOX scheme: intravenous injection of $135mg/m^2$ L-OHP on d1 for 2 h, $200mg/m^2$ CF and 1.0 g tegafur during d1~5. Whereas, control Group B received chemotherapy regimens which were same as Group A, but no addition of endostar. Before chemotherapy, patients were given intravenous injection of 8 mg ondansetron, intramuscular injection of 10 mg metoclopramide and 20 mg diphenhydramine for prevention of vomiting, protection of liver and stomach as well as symptomatic supportive treatment. One cycle was 21 d, 4~6 cycles in total. The efficacy was evaluated every 2 cycles. Results: 32 patients in Group A could be evaluated, and the response rate (RR) and disease control rate (DCR) were 59.38% and 78.13%, respectively. 31 patients in Groups could be evaluated, and the RR and DCR were 32.26% and 54.84%, respectively. The differences between 2 groups were significant. The toxic effects include myelosuppression, gastrointestinal reaction, fatigue, cardiotoxicity and peripheral neurotoxicity. Conclusions: Preliminary observations show that endostar (once every other day) combined with chemotherapy is effective in the treatment of advanced gastrointestinal cancer, with low toxic effects, good tolerance, deserving further study.