• Steel and Composite Structures
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• v.18 no.4
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• pp.925-946
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• 2015

This paper presents a new cost-effective hybrid GFRP-Concrete deck system that the GFRP panel serves as both tensile reinforcement and stay-in-place form. In order to understand the fatigue behavior of such hybrid deck, fatigue test on a full-scale specimen under sagging moment was conducted, and a series of static tests were also carried out after certain repeated loading cycles. The fatigue test results indicated that such hybrid deck has a good fatigue performance even after 3.1 million repeated loading cycles. A three-dimensional finite element model of the hybrid deck was established based on experimental work. The results from finite element analyses are in good agreement with those from the tests. In addition, flexural fatigue analysis considering the reduction in flexural stiffness and modulus under cyclic loading was carried out. The predicted flexural strength agreed well with the analytical strength from finite element simulation, and the calculated fatigue failure cycle was consistent with the result based on related S-N curve and finite element analyses. However, the flexural fatigue analytical results tended to be conservative compared to the tested results in safety side. The presented overall investigation may provide reference for the design and construction of such hybrid deck system.

• BMB Reports
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• v.37 no.6
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• pp.671-675
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• 2004

The expression and clinicopathological significance of Quox-1 gene was studied in oral squamous cell carcinoma (OSCC). Immunocytochemistry and western blot analysis were used to examine the different expressions of Quox-1 protein in 114 OSCC specimens, 34 oral epithelial dysplasia specimens, and 16 normal oral mucosa specimens. RT-PCR and virtual Northern Blot were also used to examine the expression of Quox-1 mRNA. It was found that Quox-1 was not expressed in normal epithelium. However, as dysplastic lesions progressed Quox-1 expression increased (p < 0.01), and Quox-1 expression was not significantly different between severe dysplasia and highly differentiated OSCCs (p > 0.05). As the degree of differentiation decreased, Quox-1 positivity increased in OSCC (p < 0.01), and the rate of Quox-1 (81.58%) positivity in OSCC was higher than that in normal oral mucosa (p < 0.01). Our findings imply that the positive expression of Quox-1 is correlated with the histological classification of OSCCs. Thus, the expression of Quox-1 in OSCC may serve as a significant predicting factor of proliferative status and malignant degree, and it may also be a biological detection marker of oral mucosas initial cancer and of OSCC.

• Molecules and Cells
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• v.21 no.3
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• pp.395-400
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• 2006

Glutathione S-transferase P1 (GSTP1) plays an important role in detoxification and the metabolism of xenobiotics. Here we show that GSTP1 also regulates the MEKK1-MKK7 signaling pathway. Over-expression of GSTP1 in HEK293 cells inhibited both ${\Delta}MEKK1$- and etoposide-induced apoptosis, and inhibited procaspase-3 activation and PARP cleavage. MEKK1- induced apoptosis requires both its kinase activity and proteolytic cleavage. ${\Delta}MEKK1$ activity was inhibited by over-expression of GSTP1 in vivo and MEKK1 kinase activity was also inhibited by GSTP1 in vitro when assayed with bacterially-expressed MKK7(KM) protein as substrate. GSTP1 inhibition of etoposide-induced cell apoptosis was mainly due to its ability to suppress MEKK1 kinase activity. The glutathione-conjugating activity of GSTP1 was essential for the above effects. These findings provide insight into the mechanism by which GSTP1 protects cells from genotoxin-induced apoptosis.

• Journal of Magnetics
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• v.22 no.2
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• pp.203-213
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• 2017

Magnetically suspended control & sensitive gyroscope (MSCSG) is a novel type of gyroscope with the integration of attitude control and attitude angular measurement. To improve the precision and reduce the power consumption of Lorentz Force-type Magnetic Bearing (LFMB), the air gap flux density distribution of LFMB has been studied. The uniformity of air gap flux density is defined to qualify the uniform degree of the air gap flux density distribution. Considering the consumption, the average value of flux density is defined as well. Some optimal designs and analyses of LFMB are carried out by finite element simulation. The strength of the permanent magnet is taken into consideration during the machining process. To verify the design and simulation, a high-precision instrument is employed to measure the 3-dimensional magnetic flux density of LFMB. After measurement and calculation, the uniform degree of magnetic flux density distribution reaches 0.978 and the average value of the flux density is 0.482T. Experimental results show that the optimal design is effective and some useful advice can be obtained for further research.

• Smart Structures and Systems
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• v.12 no.3_4
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• pp.291-308
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• 2013

A novel concept of transmissibility based on a wavelet transform for structural damage detection is presented in this paper. The main objective of the research was the development of a method for detecting slight damage at the incipient stage. As a vibration-based approach, the concept of transmissibility has attracted considerable interest because of its advantages and effectiveness in damage detection. However, like other vibration-based methods, transmissibility-based approaches suffer from insensitivity to slight local damage because of the regularity of the traditional Fourier transform. Therefore, the powerful signal processing techniques must be found to solve this problem. Wavelet transform that is able to capture subtle information in measured signals has received extensive attention in the field of damage detection in recent decades. In this paper, we first propose a novel transmissibility concept based on the wavelet transform. Outlier analysis was adopted to construct a damage detection algorithm with wavelet-based transmissibility. The feasibility of the proposed method was numerically investigated with a typical six-degrees-of-freedom spring-mass system, and comparative investigations were performed with a conventional transmissibility approach. The results demonstrate that the proposed transmissibility is more sensitive than conventional transmissibility, and the former is a promising tool for structural damage detection at the incipient stage.

• Wind and Structures
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• v.32 no.2
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• pp.143-159
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• 2021

The 246.8-m-tall Beijing Olympic Tower (BOT) is a new landmark in Beijing City, China. Its unique architectural style with five sub-towers and a large tower crown gives rise to complex dynamic characteristics. Thus, it is wind-sensitive, and a double-stage pendulum tuned mass damper (DPTMD) has been installed for vibration mitigation. In this study, a finite-element analysis of the wind-induced responses of the tower based on full-scale measurement results was performed. First, the structure of the BOT and the full-scale measurement are introduced. According to the measured dynamic characteristics of the BOT, such as the natural frequencies, modal shapes, and damping ratios, an accurate finite-element model (FEM) was established and updated. On the basis of wind measurements, as well as wind-tunnel test results, the wind load on the model was calculated. Then, the wind-induced responses of the BOT with the DPTMD were obtained and compared with the measured responses to assess the numerical wind-induced response analysis method. Finally, the wind-induced serviceability of the BOT was evaluated according to the field measurement results for the wind-induced response and was found to be satisfactory for human comfort.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.1-7
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• 2020

In this study, a multichannel gas-liquid microextraction system is designed by integrating the automatic elution of extraction line and multichannel gas-purging liquid phase microextraction. The system uses an injection pump and inert gas to push the extraction solvent to a sample bottle of a gas-phase color autosampler and then implements multichannel gas-liquid microextraction and gas chromatography-mass spectrometry. The system also employs a three-way integrated micro-high-temperature heater, syringe pump, and microflow controller to realize the simultaneous processing of multiple groups of samples, thus improving the sample pretreatment speed and reproducibility and reducing human error. Autoinjection experiments were implemented with polycyclic aromatic hydrocarbon standard samples. The experiments show that the average recovery rate of the system exceeds 70%, and the relative standard among the channels is less than 15%.

• Structural Engineering and Mechanics
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• v.77 no.1
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• pp.19-35
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• 2021

Existing methods to estimate the probability of seismic pounding occurrence of adjacent buildings do not account for nonlinear behavior or only apply to simple lumped mass systems. The present study proposes an efficient method based on subset simulation for fragility and risk assessment of seismic pounding occurrence between nonlinear adjacent buildings neglecting pounding effects with application to finite element models. The proposed method is first applied to adjacent buildings modeled as elastoplastic systems with substantially different dynamic properties for different structural parameters. Seismic pounding fragility and risk of adjacent frame structures with different floor levels is then assessed, paying special attention to modeling the non-linear material behavior in finite element models. Difference in natural periods and impact location are identified to affect the pounding fragility simultaneously. The reliability levels of the minimum code-specified separation distances are also determined. In addition, the incremental dynamic analysis method is extended to assess seismic pounding fragility of the adjacent frame structures, resulting in higher fragility estimates for separation distances larger than the minimum code-specified ones in comparison with the proposed method.

• Steel and Composite Structures
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• v.42 no.3
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• pp.299-313
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• 2022

Steel-concrete-steel composite structures with bidirectional webs (SCSBWs) are used in large-scale projects and exhibit good mechanical performances and constructional efficiency. The shear behaviors of SCSBW deep beam members in key joints or in locations subjected to concentrated forces are of concern in design. To address this issue, experimental program is investigated to examine the deep-beam shear behaviors of SCSBWs, in which the cracking process and force transfer mechanism are revealed. Compared with the previously proposed truss model, it is found that a strut-and-tie model is more suitable for describing the shear mechanism of SCSBW deep beams with a short span and sparse transverse webs. According to the experimental analyses, a new model is proposed to predict the shear capacities of SCSBW deep beams. This model uses strut-and-tie concept and introduces web shear and dowel action to consider the coupled multi mechanisms. A stress decomposition method is used to distinguish the contributions of different shear-transferring paths. Based on case studies, a simplified model is further developed, and the explicit solution is derived for design efficiency. The proposed models are verified using experimental data, which are proven to have good accuracy and efficiency and to be suitable for practical application.

• Fourth Industrial Review
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• v.2 no.2
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• pp.39-46
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• 2022

Purpose - This study analyzes the investment environment of South Korea by using the rating scale of Robert B Stobaugh, Jr, and draws conclusion implication. Research design, data, and methodology - The study conducted a survey on according to the political stability, capital repatriation, foreign ownership allowed, discrimination and controls, foreign vs domestic businesses, currency stability, willingness to grant tariff protection, availability of local capital, and annual inflation for last 5 years. The score of these eight aspects will be given based on the current situation in South Korea and the sum of the scores will be calculated. Result - China-Korea economic and trade relations are in a stage of transformation and upgrading, and the level of economic and trade cooperation in various fields is reaching a new level. It is hoped that Chinese enterprises will grasp business opportunities, strengthen research and analysis of the Korea market and achieve mutually beneficial cooperation. Conclusion - The investment environment of South Korea is superior according to the political stability, capital repatriation, foreign ownership allowed, discrimination and controls, foreign vs domestic businesses, currency stability, willingness to grant tariff protection, availability of local capital, and annual inflation for last 5 years.