• Steel and Composite Structures
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• v.36 no.1
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• pp.31-45
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• 2020

The purpose of this study is to develop an effective iterative two-stage method (ITSM) for structural damage identification of offshore platform structures. In each iteration, a new damage index, Modal Energy-Based Damage Index (MEBI), is proposed to help effectively locate the potential damage elements in the first stage. Then, in the second stage, the beetle antenna search (BAS) algorithm is used to estimate the damage severity of these elements. Compared with the well-known particle swarm optimization (PSO) algorithm and genetic algorithm (GA), this algorithm has lower computational cost. A modal energy based objective function for the optimization process is proposed. Using numerical and experimental data, the efficiency and accuracy of the ITSM are studied. The effects of measurement noise and spatial incompleteness of mode shape are both considered. All the obtained results show that under these influences, the ITSM can accurately identify the true location and severity of damage. The results also show that the objective function based on modal energy is most suitable for the ITSM compared with that based on flexibility and weighted natural frequency-mode shape.

• Journal of Korea Multimedia Society
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• v.24 no.10
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• pp.1380-1390
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• 2021

The video face recognition (FR) is one of the most popular researches in the field of computer vision due to a variety of applications. In particular, research using the attention mechanism is being actively conducted. In video face recognition, attention represents where to focus on by using the input value of the whole or a specific region, or which frame to focus on when there are many frames. In this paper, we propose a novel attention based deep learning method. Main novelties of our method are (1) the use of combining two loss functions, namely weighted Softmax loss function and a Triplet loss function and (2) the feasibility of end-to-end learning which includes the feature embedding network and attention weight computation. The feature embedding network has a positive effect on the attention weight computation by using combined loss function and end-to-end learning. To demonstrate the effectiveness of our proposed method, extensive and comparative experiments have been carried out to evaluate our method on IJB-A dataset with their standard evaluation protocols. Our proposed method represented better or comparable recognition rate compared to other state-of-the-art video FR methods.

• Journal of Convergence for Information Technology
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• v.10 no.5
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• pp.126-133
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• 2020

This study was conducted with a randomized control group pretest-posttest study design to investigate the effects of a combined arts education program combining choral and respiratory training on the respiratory function, stress, and quality of life of university students. Twenty-five university students were randomly assigned to the experimental group (n=13) who participated in the combined arts education program and the control group (n=12) who participated in the general arts education program. As a result, there was a significant difference in the lung capacity, respiratory strength, stress and quality of life scale before and after the experiment in the experimental group (p<0.05). In addition, the results of the rest of the tests showed significant differences (p<0.05), except for the result FEV1. Through the results of this study, the combined art education program that combines chorus and breathing training will be beneficial as a program to improve stress reduction, breathing function and quality of life of university students.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1490-1494
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• 2006

Most network equipment is an embedded system designed to execute specific function. An embedded system is an electronic control system mixing hardware and software to execute only fixed function for the purpose of system, not confuter, performing diverse function for a wide use. Early embedded system executed only simple function, combining specific function with optimization, a micro size, and low power, but it has developed to meet complex and diverse system. The purpose of this study is to realize DHCP server based on embedded system. To achieve this, embedded Linux was ported in ez Bord-M01 mounted with Intel Strong ARM SA1110 processor, and ethernet-based network was constructed for network function. In this way, this study suggests embedded DHCP server where Window and Linux client hosts are dynamically configurated as network information by dynamically assigning network information in embedded board.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1433-1440
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• 2015

In this paper, we propose an unambiguous correlation function to improve tracking performance for binary offset carrier (BOC) signals. Specifically, we divide a BOC sub-carrier into multiple rectangular pulses, and analyze that the BOC autocorrelation function is made up of the sum of several partial correlation functions. Then, we obtain two sub-correlation functions by combining two partial correlation functions and propose a novel unambiguous correlation function with no side-peak which can be regulated its width based on the combination of the sub-correlation functions and partial correlation functions. From numerical results, it is confirmed that the proposed correlation function provides a tracking performance improvement over the conventional correlation functions in terms of the tracking error standard deviation.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.2
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• pp.96-108
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• 2022

In this paper, we propose a systematic hull form variation technique which automatically satisfies the displacement constraint and guarantees a high level of fairness. This method is possible through multiple parameter correction curves. The present method is to improve the hull form variation method based on parametric modification function and consists of two sub-categories: SAC variation and section lines modification. For SAC variation, the utilization of two B-Spline curves satisfying GC¹ condition led to the satisfaction of displacement constraint and high level of fairness at the same time. Section lines modification methods involves in using two fuctions: the first is the waterplane modification function combining two cubic splines. the other function is the sectional area modification function consisting of 2nd order polynomial over the DLWL(Design Load Waterline) and 3rd order polynomial below the DLWL, This function enables not only the fundamental U-V section shape variation but also systematically modified section lines. The present method is expected to be more useful in the hull form optimization process using CFD compared to the existing method.

• Physical Therapy Rehabilitation Science
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• v.5 no.4
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• pp.163-169
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• 2016

Objective: The purpose of this study was to investigate the effects of vibration resistance exercise (VRE) in patients with tennis elbow on strength, range of motion (ROM), function, pain and quality of life (QOL). Design: Randomized controlled trial. Methods: Twenty-seven participants were randomly assigned to either the VRE group (n=9), weight resistance exercise (WRE) group (n=9) or control group (n=9). Each group underwent hot compress for 15 minutes and electrotherapy for 15 minutes. The VRE group underwent exercises using a vibrating ball for 5 minutes. The WRE group underwent exercises using dumbbells for 5 minutes. All participants were evaluated on wrist extension strength using a hand-held dynamometer, grip strength level through an electric dynamometer, and ROM through a smartphone goniometer application before and after intervention. Patient-rated tennis elbow evaluation, Visual Analogue Scale and Short Form 8 were measured by questionnaires. Results: There were showed significant differences among the VRE, WRE and control group in wrist extensor muscle and hand grip strength, ROM, elbow function, pain and QOL after intervention (p<0.05). The VRE group showed a greater significant improvement in wrist extensor muscle strength and elbow function compared with the others (p<0.05). The VRE and the WRE groups had a more significant improvement in wrist extensor muscle and hand grip strength, ROM and pain compared with the control group (p<0.05). However, there were no significant differences in QOL among the three groups. Conclusions: Combining VRE with thermotherapy and electrotherapy appears to be more effective in improving wrist extension strength, ROM, elbow function, QOL in tennis elbow patients.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.1
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• pp.1-10
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• 2022

Deep neural networks are widely used to solve various problems. In a fully connected neural network, the nonlinear activation function is a function that nonlinearly transforms the input value and outputs it. The nonlinear activation function plays an important role in solving the nonlinear problem, and various nonlinear activation functions have been studied. In this study, we propose a combined parametric activation function that can improve the performance of a fully connected neural network. Combined parametric activation functions can be created by simply adding parametric activation functions. The parametric activation function is a function that can be optimized in the direction of minimizing the loss function by applying a parameter that converts the scale and location of the activation function according to the input data. By combining the parametric activation functions, more diverse nonlinear intervals can be created, and the parameters of the parametric activation functions can be optimized in the direction of minimizing the loss function. The performance of the combined parametric activation function was tested through the MNIST classification problem and the Fashion MNIST classification problem, and as a result, it was confirmed that it has better performance than the existing nonlinear activation function and parametric activation function.

• Environmental and Resource Economics Review
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• v.13 no.3
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• pp.337-366
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• 2004

Contingent Valuation Method (CVM), as non-market valuation approach, has been criticized on that respondents may not realistically reflect their budget constraints in answering willingness to pay (WTP) for hypothetical CV questions. This paper empirically estimates the income calibration factor associated with CV responses through combining travel cost method and contingent valuation method in a utility-theoretic framework. The joint model of recreation demand function and contingent WTP function was applied to an important case study on the Man Kyoung River system, whose water quality is at issue because of the Sae Alan Kum reclamation project. Relevant economic variables such as price, income and water quality had significant influence as anticipated by the economic theory. Equally important, the income calibration factor was not significantly different from one, suggesting that the systematic discrepancies of CV responses relative to the actual behavior was not detected at least in terms of budget exaggeration. Overall, this study supports the notion that carefully designed CVM studies can provide informative data on individuals' willingness to pay for environmental quality changes.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.1257-1268
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• 2015

Multi-functional devices was originally an equipment performing image processing, but function transmitting image data digitized by combining fax function and function of network are added and it was rapidly developed. Also, functions of internet application, application expansion, remote sharing and image treatment were added to multi-functional devices. But, multi-functional devices can cause security vulnerability such as data exposure, eavesdropping, etc. because of the threatening by network connection. Therefore, common criteria of multi-functional devices are necessary, but there is no protection profile for multi-functional devices now. Therefore, concrete standards of evaluation are not applied to evaluate secure for products, so it was difficult to maintain uniformity of evaluation quality. Therefore, this paper developed protection profile for multi-functional devices based on common criteria of evaluation so as to analyze threats of multi-functional devices and use secure multi-functional devices.