• Computational Structural Engineering : An International Journal
• /
• v.1 no.1
• /
• pp.1-9
• /
• 2001

Collapse behavior of Mission-Gothic Undercrossing under Northridge earthquake is studied by performing nonlinear time-history analysis and three-dimensional nonlinear finite element method for flared columns. Bridge structural model is characterized as three-dimensional with consideration of columns, superstructures, and abutment conditions. Three components of ground motion, corresponding to bridge's longitudinal, transverse, and vertical direction and their combinations are used to investigate bridge collapse. Studies indicate that bridge collapse is dominantly caused by transverse ground motion and the consideration of three-dimensional ground motion leads to a more accurate assessment. Failure mechanism of flared columns is analyzed applying nonlinear finite element method. Reduction of column capacity is observed due to orientation of flare. Further investigation demonstrates that the effects of flare play an important role in predicting of bridge failure mechanism. Suggestions are offered to improve the performance of bridges during severe earthquake.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.9
• /
• pp.2202-2217
• /
• 2012

The transmission opportunities between nodes in Delay Tolerant Network (DTNs) are uncertain, and routing algorithms in DTNs often need nodes serving as relays for others to carry and forward messages. Due to selfishness, nodes may ask the source to pay a certain reward, and the reward may be varying with time. Moreover, the reward that the source obtains from the destination may also be varying with time. For example, the sooner the destination gets the message, the more rewards the source may obtain. The goal of this paper is to explore efficient ways for the source to maximize its total reward in such complex applications when it uses the probabilistic two-hop routing policy. We first propose a theoretical framework, which can be used to evaluate the total reward that the source can obtain. Then based on the model, we prove that the optimal forwarding policy confirms to the threshold form by the Pontryagin's Maximum Principle. Simulations based on both synthetic and real motion traces show the accuracy of our theoretical framework. Furthermore, we demonstrate that the performance of the optimal forwarding policy with threshold form is better through extensive numerical results, which conforms to the result obtained by the Maximum Principle.

• Current Optics and Photonics
• /
• v.4 no.3
• /
• pp.210-220
• /
• 2020

Aiming at the problem that the Local Sparse Difference Index algorithm has low accuracy and low efficiency when detecting target anomalies in a hyperspectral image, this paper proposes a Weighted Collaborative Representation and Sparse Difference-Based Hyperspectral Anomaly Detection algorithm, to improve detection accuracy for a hyperspectral image. First, the band subspace is divided according to the band correlation coefficient, which avoids the situation in which there are multiple solutions of the sparse coefficient vector caused by too many bands. Then, the appropriate double-window model is selected, and the background dictionary constructed and weighted according to Euclidean distance, which reduces the influence of mixing anomalous components of the background on the solution of the sparse coefficient vector. Finally, the sparse coefficient vector is solved by the collaborative representation method, and the sparse difference index is calculated to complete the anomaly detection. To prove the effectiveness, the proposed algorithm is compared with the RX, LRX, and LSD algorithms in simulating and analyzing two AVIRIS hyperspectral images. The results show that the proposed algorithm has higher accuracy and a lower false-alarm rate, and yields better results.

• International Journal of Costume and Fashion
• /
• v.14 no.1
• /
• pp.75-93
• /
• 2014

Facing a mature domestic market and the challenges of the global consumer market, retailers in Taiwan are in pursuit of international development strategies for increasing its market opportunities as one of its key growth strategies. In the global market, the Chinese market becomes Taiwan retailers' main international development milestone due to its similarity of language, culture and historical background with China. Therefore, this research uses case study method based on Eclectic paradigm (Dunning 1981) to explore the various advantages of a Taiwanese children's clothing retailer Les Enphants, which include ownership advantage, internalization advantage, and location advantage. These advantages in turn demonstrate rationales behind Les Enphants' internationalization necessity (Why to Go), selecting China as an expansion target (Where to Go), and management and operation strategies implemented in China (How to Go). Our study highlights a successful entry and expansion model of the Taiwanese children clothing retailer, and may have solid contribution to the practical application of internationalization strategy theory.

• Geomechanics and Engineering
• /
• v.18 no.3
• /
• pp.225-234
• /
• 2019

A numerical stepwise approach for cavity expansion problem in strain-softening rock or soil mass is investigated, which is compatible with Mohr-Coulomb and generalized Hoek-Brown failure criteria. Based on finite difference method, plastic region is divided into a finite number of concentric rings whose thicknesses are determined internally to satisfy the equilibrium and compatibility equations, the material parameters of the rock or soil mass are assumed to be the same in each ring. For the strain-softening behavior, the strength parameters are assumed to be a linear function of deviatoric plastic strain (${\gamma}p^*$) for each ring. Increments of stress and strain for each ring are calculated with the finite difference method. Assumptions of large-strain for soil mass and small-strain for rock mass are adopted, respectively. A new numerical stepwise approach for limited pressure and plastic radius are obtained. Comparisons are conducted to validate the correctness of the proposed approach with Vesic's solution (1972). The results show that the perfectly elasto-plastic model may underestimate the displacement and stresses in cavity expansion than strain-softening coefficient considered. The results of limit expansion pressure based on the generalised H-B failure criterion are less than those obtained based on the M-C failure criterion.

• Smart Structures and Systems
• /
• v.23 no.3
• /
• pp.279-293
• /
• 2019

To ensure high quality data being used for data mining or feature extraction in the bridge structural health monitoring (SHM) system, a practical sensor fault diagnosis methodology has been developed based on the similarity of symmetric structure responses. First, the similarity of symmetric response is discussed using field monitoring data from different sensor types. All the sensors are initially paired and sensor faults are then detected pair by pair to achieve the multi-fault diagnosis of sensor systems. To resolve the coupling response issue between structural damage and sensor fault, the similarity for the target zone (where the studied sensor pair is located) is assessed to determine whether the localized structural damage or sensor fault results in the dissimilarity of the studied sensor pair. If the suspected sensor pair is detected with at least one sensor being faulty, field test could be implemented to support the regression analysis based on the monitoring and field test data for sensor fault isolation and reconstruction. Finally, a case study is adopted to demonstrate the effectiveness of the proposed methodology. As a result, Dasarathy's information fusion model is adopted for multi-sensor information fusion. Euclidean distance is selected as the index to assess the similarity. In conclusion, the proposed method is practical for actual engineering which ensures the reliability of further analysis based on monitoring data.

• Structural Engineering and Mechanics
• /
• v.70 no.5
• /
• pp.623-637
• /
• 2019

This paper analyzes the non-stationary vibration and super-harmonic resonances in nonlinear dynamic motion of viscoelastic nano-resonators. For this purpose, a new coupled size-dependent model is developed for a plate-shape nano-resonator made of nonlinear viscoelastic material based on modified coupled stress theory. The virtual work induced by viscous forces obtained in the framework of the Leaderman integral for the size-independent and size-dependent stress tensors. With incorporating the size-dependent potential energy, kinetic energy, and an external excitation force work based on Hamilton's principle, the viscous work equation is balanced. The resulting size-dependent viscoelastically coupled equations are solved using the expansion theory, Galerkin method and the fourth-order Runge-Kutta technique. The Hilbert-Huang transform is performed to examine the effects of the viscoelastic parameter and initial excitation values on the nanosystem free vibration. Furthermore, the secondary resonance due to the super-harmonic motions are examined in the form of frequency response, force response, Poincare map, phase portrait and fast Fourier transforms. The results show that the vibration of viscoelastic nanosystem is non-stationary at higher excitation values unlike the elastic ones. In addition, ignoring the small-size effects shifts the secondary resonance, significantly.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.1
• /
• pp.399-408
• /
• 2022

This paper aims to evaluate the effects of Critical work factors on Work Motivation and Job Satisfaction of young Vietnamese employees. The four most essential work aspects were consisting of the Work environment, Employee empowerment, Salary, and Promotion opportunities. To empirically evaluate the proposed research model, the authors assemble data through conducting questionnaire interviews with young employees working in Vietnamese firms. A sample of 216 respondents was constructed using the PLS-SEM program to highlight the testing of thirteen hypotheses. The testing results indicate that four Critical work factors positively impact the job motivation of young employees, especially two factors as Salary and Promotion opportunities. Surprisingly, the hypothesis regarding the positive direct relationship between Promotion opportunities and Job satisfaction is not supported. Meanwhile, the rest influence factors have a significant connection with the Vietnamese worker's job satisfaction. The mediation role of Work motivation was also tested by examining the indirect positive relationship between four Critical work factors and Job satisfaction. This paper is the first study that focuses on young employees; hence, these research findings provide Vietnamese human resource managers some suggestions for reference, which can be considered the dynamic factors on the young Vietnamese employees.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.4
• /
• pp.828-837
• /
• 2024

Vancomycin (VAN) and metronidazole (MTR) remain the current drugs of choice for the treatment of non-severe Clostridioides difficile infection (CDI); however, while their co-administration has appeared in clinical treatment, the efficacy varies greatly and the mechanism is unknown. In this study, a CDI mouse model was constructed to evaluate the therapeutic effects of VAN and MTR alone or in combination. For a perspective on the intestinal ecology, 16S rRNA amplicon sequencing and non-targeted metabolomics techniques were used to investigate changes in the fecal microbiota and metabolome of mice under the co-administration treatment. As a result, the survival rate of mice under co-administration was not dramatically different compared to that of single antibiotics, and the former caused intestinal tissue hyperplasia and edema. Co-administration also significantly enhanced the activity of amino acid metabolic pathways represented by phenylalanine, arginine, proline, and histidine, decreased the level of deoxycholic acid (DCA), and downregulated the abundance of beneficial microbes, such as Bifidobacterium and Akkermansia. VAN plays a dominant role in microbiota regulation in co-administration. In addition, co-administration reduced or increased the relative abundance of antibiotic-sensitive bacteria, including beneficial and harmful microbes, without a difference. Taken together, there are some risks associated with the co-administration of VAN and MTR, and this combination mode should be used with caution in CDI treatment.

• International conference on construction engineering and project management
• /
• 2011.02a
• /
• pp.318-323
• /
• 2011

Illegal and unethical behaviors of the construction industry affect people's lives and health more than the same problems of the other industries. Among these behaviors, the construction industry is mostly criticized for bribery scandals. According to the survey of the Ministry of Justice in Taiwan over the past years, bribery cases involving public engineering projects and governmental procurements account for a rather large portion of the indicted corruption cases. Transparency International's "Bribe Payer Index" indicates people in construction-related industries are the most likely to pay bribes. Poor construction quality directly and indirectly caused by bribery poses a great threat to public safety, organizational reputation and economic development. However, there is a limited number of existing research on the bribery problem of the construction industry. This study is an empirical attempt to explore bribery intention and its affecting factors among the construction organizations in Taiwan by conducting a questionnaire survey. The theory of planned behavior was used in this study to build its research model (covering elements of attitude, subjective norm, perceived behavior control, and intention). Totally 431 valid samples were returned. To explore the factors affecting bribery intention, this study adopted Pearson's correlation analysis to discuss about the connections among the questionnaire respondents' attitudes to bribery, subjective norms, perceived behavior control, and bribery intention. A multi-regression analysis was then conducted to test if the planned behavior theory can effectively predict bribery intention. The research found (1) according to the results of Pearson's correlation analysis, the respondents' bribery intention, attitudes, subjective norms, and perceived behavior control are positively correlated with one another; (2) according to the results of the multi-regression analysis, bribery intention can be explained through attitudes, subjective norms, and perceived behavior control with an adjusted R² value of 0.591, meaning 59.1% of the bribery intention's variances can be explained through the three dimensions. In addition, each of the three dimensions has a significant influence on the respondents' behavior intentions.