Yong Hong

Altered frequency and migration capacity of CD4+CD25+ regulatory T cells in systemic lupus erythematosus

OBJECTIVES To determine the frequency and chemokine receptor-related migratory capacity of CD4(+)CD25(+) regulatory T cells (Tregs) and their association with clinical parameters in patients with SLE. METHODS The expression of CD4, CD25, FoxP3 and CCR4 was examined with flow cytometry after staining with fluorescence-conjugated antibodies in 20 patients with SLE, 20 patients with RA and 21 age- and sex-matched healthy controls. For analysis of migration capacity in 24-well chemotaxis chambers, sorted cells were stimulated with ligands of CCR4, CCL17 and CCL22 and analysed with FACScan. Correlations between the number of Tregs and CCR4(+) Treg cells and clinical parameters were analysed. RESULTS The numbers of Tregs(bright) and CCR4(+) Tregs(bright) were significantly decreased in the patients with SLE compared with healthy controls. The number of Tregs(bright) was negatively correlated with the levels of anti-dsDNA antibody and the number of CCR4(+) Tregs(bright) had a positive correlation with the levels of C(3). Percentage of migrated Tregs(bright) by CCL17 or CCL22 was significantly decreased in the patients with SLE compared with healthy controls. CONCLUSIONS These results suggest that altered frequency of Tregs and CCR4(+) Tregs(bright) and decreased migratory capacity of Tregs might be involved in the pathogenesis of SLE and indicate that targeting the Tregs can be a new therapeutic strategy in SLE.

DAMAGE DETECTION OF TRUSS-LIKE STRUCTURES USING WAVELET TRANSFORMS

This study deals with the application of wavelet transforms to the damage detection of truss-like structures. The principles of damage detection by using the wavelet transforms are interpreted and the damage detection capabilities of wave transforms for cracks are demonstrated by numerical and experimental methods. Numerical simulation in combination with the wavelet transforms provides reliable numerical results and the guided wave method using smart materials enables the experimental verification of the numerical results. The basic component elements of truss structures, i.e., beams, are studied first, and subsequently complex structures are considered. The information extracted from the simulation data by using the wavelet transforms shows considerably accurate signatures for localization of damages. In particular, the study considers the influence of structural discontinuities and loading points on damage detection of crack localization. The information extracted from the signal by using the numerical and experimental methods employing the wavelet transforms shows the robustness of the methods in detecting damages in simple and complex structures.

Estimation for Bolt Fastening Conditions of Thin Aluminum Structure Using PZT Sensors

This work presents a study on PZT impedance-based method, it is one of the NDT(Non-Destructive Technique). We study about assessment of the square-structure health condition by impedance-based technique using PZT patches, associated with longitudinal wave propagation. Health conditions of the square-structure controlled by bolt fastening condition is adjusted by torque wrench. In order to estimate the damage condition numerically, we suggest the evaluation method of impedance peak frequency shift.

Design Optimization of Composite-Insulated Telescopic Aerial Boom

Telescopic aerial boom system is used transport the object or can be used to ease working high altitude. Installation of high voltage transmission tower due to urbanization is increasing. Because working on high places such as wiring operations and electrical maintenance has increased the demand.Boom of aerial work platform are made of steel. So, necessity for safe isolation aerial work platform used for electrical work is increasing. This paper is proposed about applied to the material used in the aerial work platform boom. Insulating material was applied to the aerial work platform the last end boom in boom system. In this paper the structural analysis and formulation of the methodology for the design optimization of telescopic aerial lift boom system is presented. The main objective of the design optimization is to obtain lightweight boom system by optimizing boom cross-section shape, overlap length and plate thicknesses in the worst condition possible. The design optimization problem is formulated as minimizing the weight of the boom system. In this paper analyzes the design of the telescopic aerial boom system of applying the insulating material using the Ansys.

Structural Analysis of Boom System in 42m Aerial Platform Truck

In the study, the development of aerial platform truck of 42m boom system has been completed to be satisfied with working in much higher place. To avoid the rollover accident of vehicles while working, 3D FEA is applied to verify the 3D design, stress concentration, stress distribution, deflection, natural frequencies etc. In these analyses, traction load of Boom System, 700 Kg and traction degree analyzed to 0° ~ 85°. Analysis result, when Boom Systems angle is 0°, could know that stress concentration and deflection are obtained to maximum. We could predict that maximum point of Stress concentration is 3.275 as safety factor and deflection of Boom system end part is max. 78.5Cm. Also could know that natural frequency and mode shape of boom system are stable in correlation with aerial platform trucks operation area. With these results, the structural stability of boom system in 42m aerial platform truck is obtained, then finally trying to find an optimum design of aerial platform truck.

Damage Detection and Quantitative Assessment for the Cracked Beam Structures

Beam structures are a common form in many large structures, and therefore the real-time condition monitoring and active control of beams will improve the reliability and safety of many structures. However, the incipient damage, i.e. cracks, is not easy to be detected with using the traditional methods, such as modal analysis, etc. Piezoceramic (PZT) sensors offer special opportunities for the health monitoring of structures constructed by beams. The change of mechanical impedance of structures along with the occurrence of damage is sensitively indicated by the change of electro-impedance of PZT sensors. This paper presents work done on developing and utilizing PZT sensors to detect and quantitatively assess the extent and locations of cracks occurred in simulated structures. The PZT sensors are conducted particularly to generate the longitudinal wave along the beam specimen, and systematic experiments conducted on statistical samples of incrementally damaged specimens were used to fully understand the method, the cracks with different length and location are simulated to indicate the feasibility of the detection and assessment. To estimate the damage conditions numerically, in this paper, we propose the evaluation method of impedance peak frequency shift F and CC (Correlation Coefficient), Cov (Covariance). The results of experiments verify that the impedance peak frequency shift Δ F uniformly assesses the location of cracks, and as well CC. and Cov assesses the size of cracks efficiently. The study presents the method that is satisfied for much higher frequencies, alternate power, and minute damages.

Composite-Insulated Boom FEM Analysis for the Application of Aerial Work Platform

Telescopic aerial boom system is used transport the object or can be used to ease working high altitude. Installation of high voltage transmission tower due to urbanization is increasing. Because working on high places such as wiring Operations and electrical maintenance has increased the demand. Boom of aerial work platform are made of steel. So, necessity for safe isolation aerial work platform used for electrical work is increasing. This paper is proposed about applied to the material used in the aerial work platform boom. Insulating material was applied to the aerial work platform the last end boom in boom system. In this paper aerial work platform boom is characterized by apply insulating material and lightweight through self-load reduction and isolation. In this paper analyzes the design of the telescopic aerial boom system of applying the insulating material using the ansys. Then design was verified through comparison of the insulation telescopic aerial lift system and Mass-produced existing telescopic aerial boom system.

Design Optimization of the Aerial Lift Boom through the Finite-Element Analysis (FEA)

The multi-stage boom consisting of several booms is used in order to develop the aerial platform truck that can be used in a working radius that is higher and safe. Because the length increases compared with the width or the height of the structure, the intensity and rigidity are lowered along with the safety. Accordingly, a countermeasure is needed. Therefore, in this research, when designing of the high ground work difference Boom System, the safety the stress of the considered boom the analyze method and experimental method tries to be evaluated through the comparison. The finite-element analysis(FEA) compared the Strain value which is obtained through the resolution value and actual experiment by using the Ansys,that is the general purpose program, and proved this safety.

The Response Characteristics of Various Impact Patterns on the Smart Bumper of Automotives

In this paper, a pendulum system is constructed to perform the fundamental research which is concentrated on the various frequency patterns of impact-object simulation tests. We confirmed the application possibility for the method of discriminable pattern recognition whether impact-object is human-like or not via frequency analysis using smart sensors. Therefore a specific experimental data are compared and analyzed with the obtained database within a short time period. The impact analysis system, which is based on the above processing, can be developed and then used to recognize the impact information measured by smart sensors.

Detection of Various Damages Based on Piezoceramic Optical Fiber Sensor

A piezoelectric ultrasonic sensing system based on an optical fiber has been developed for detection of various damages. The ultrasonic wave generated from a piezoelectric actuator is guided and propagated in the optical fiber and then sensed by a piezoelectric sensor located at the other end of the fiber. The sensed signal can be influenced by environmental and physical changes around the optical fiber. In this study, the sensitivity of the optical fiber sensor is experimentally studied. Various patterns of damage, such as cracks, loosen bolts, holes, are more common forms in real structures. In particular, detection method of the damage with respect to various depths of the crack is presented in this paper.