• Journal of Korean Association for Spatial Structures
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• v.22 no.3
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• pp.41-48
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• 2022

The purpose of this study is to evaluate seismic performances of a modular house system developed by a simple 4-clip fastening method and double metal assembly made of lightweight metals. In order to evaluate structural and non-structural seismic performances of the system. Shaking table test was carried out with full-scale modular units, and a nonlinear pushover analysis was performed to obtain suitable seismic responses for story drifts, displacements, force resistances and dynamic properties of the system. Through 3D analysis and shaking table test, the current method of lightweight modular metal unit assembly and systems with seismic performance of a 4-clip fastening type modular house were demonstrated safe and effective to seismic design.

• Journal of information and communication convergence engineering
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• v.20 no.2
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• pp.131-136
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• 2022

The recommendation system applied in museums has been widely adopted owing to its advanced technology. However, it is unclear which recommendation is suitable for indoor museum guidance. This study evaluated a recommender system based on social-filtering and statistical methods applied to actual museum databases. We evaluated both methods using two different datasets. Statistical methods use collective data, whereas social methods use individual data. The results showed that both methods could provide significantly better results than random methods. However, we found that the trip time length and the dataset's sizes affect the performance of both methods. The social-filtering method provides better performance for long trip periods and includes more complex calculations, whereas the statistical method provides better performance for short trip periods. The critical points are defined to indicate the trip time for which the performances of both methods are equal.

• ETRI Journal
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• v.45 no.5
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• pp.811-821
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• 2023

We propose an adaptive unmanned aerial vehicle (UAV)-assisted object recognition algorithm for urban surveillance scenarios. For UAV-assisted surveillance, UAVs are equipped with learning-based object recognition models and can collect surveillance image data. However, owing to the limitations of UAVs regarding power and computational resources, adaptive control must be performed accordingly. Therefore, we introduce a self-adaptive control strategy to maximize the time-averaged recognition performance subject to stability through a formulation based on Lyapunov optimization. Results from performance evaluations on real-world data demonstrate that the proposed algorithm achieves the desired performance improvements.

• Korean Journal of Computational Design and Engineering
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• v.15 no.1
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• pp.51-59
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• 2010

People evaluate urban residential regions quite frequently and sensitively, considering issues such as locations or ease of use of in-site facilities or nearby urban facilities, and those results are bound to be reflected to real estate costs quite immediately. However, there have been frequently recurring questions regarding objectivity of evaluations in terms of results and methods reflected on indexes such as land costs for various reasons. RPMS -Residence Performance Management System- which targets currently in most cases on urban residential areas, suggests instrumental methodology of objective approach toward sensitive urban residence performance evaluation. This paper explains and suggests instrumental utilization of RPMS and its implementations, evaluation methodology and quantitative way of evaluation. In terms of implementation we explain issues such as adding target locations into new residence planning sites, quantification of properties on evaluation indexes of residential performance and/or habitability in terms of checklists, formulas for evaluation, delicate adjustment of evaluation results by setting weights on evaluation indexes, as well as reports on results. Research on appropriate weights and weight settings regarding evaluation indexes, however, exceeds the range of this paper so that this paper focuses on explaining residence performance evaluation and management methodology.

• Journal of the Korea Society of Computer and Information
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• v.25 no.2
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• pp.123-131
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• 2020

The text ranking algorithm is a representative method for keyword extraction, and its importance is emphasized highly. In this paper, we compare the performance of recent research and experiments with TF-IDF, SMART, INQUERY and CCA algorithms, which are used in text ranking algorithm.. After explaining each algorithm, we compare the performance of each algorithm based on the data collected from news and Twitter. Experimental results show that all of four algorithms can extract specific words from news data equally. However, in the case of Twitter, CCA has the best performance to extract specific words, and INQUERY shows the worst performance. We also analyze the accuracy of the algorithm through six comparison metrics. The experimental results present that CCA shows the best accuracy in the news data. In case of Twitter, TF-IDF and CCA show similar performance and demonstrate good performance.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.4
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• pp.425-434
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• 2010

This study presents the alternative evaluation technique for the high-rise building structural system. The alternative evaluation of the structural system is performed in three steps, that is, preliminary evaluation, main evaluation and detailed evaluation. The evaluation categories are composed of structural performance, economic feasibility and term of work. Each categories are composed of detailed items to evaluate of its own. In preliminary evaluation, qualitative evaluation based on experimental knowledge is performed. In main and detailed evaluations, quantitative evaluations based on numeric data are performed. The weighted-sum method is applied to integrate the evaluated results of each items and its importance. The applicability of the proposed method was verified by applying it to the practical buildings and simulate the procedures.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1924-1934
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• 2011

This paper is concerned with the robustness evaluations of the guidance controller for a bimodal tram which is being developed by the Korea Railroad Research Institute (KRRI). The bimodal tram is an all-wheel steered multiple-articulated vehicle as a new kind of transportation vehicle. This vehicle has to be equipped with an automatic guidance system. In [1], such a controller has been recently proposed. However, since the performance is affected by weight change of the vehicle due to number of the passenger, model parameter uncertainties depending on the state of friction and the elasticity of the tire, and a typhoon, the controller designed must be examined with these conditions. As expected, because the vehicle dynamics is highly nonlinear, for the sake of investigating the robustness of the controller we compose two simulation ways based on the vehicle models which are implemented by the ADAMS and the MATLAB/LabVIEW toolboxes. Different uncertainties and a typhoon disturbance have been considered for the simulation conditions. Simulation results are shown.

• Earthquakes and Structures
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• v.11 no.4
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• pp.701-721
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• 2016

Base isolation is a well-established passive strategy for seismic response control of buildings. In this paper, an efficient framework is proposed for reliability-based design optimization (RBDO) of isolated buildings subjected to uncertain earthquakes. The framework uses reduced function evaluations method, as an efficient tool for structural reliability analysis, and an efficient optimization algorithm for optimal structural design. The probability of failure is calculated considering excessive base displacement, superstructure inter-storey drifts, member stress ratios and absolute accelerations of floors of the isolated building as failure events. The behavior of rubber bearing isolators is modeled using nonlinear hysteretic model and the variability of future earthquakes is modeled by applying a probabilistic approach. The effects of pulse component of stochastic near-fault ground motions, fixity-factor of semi-rigid beam-to-column connections, values of isolator parameters, earthquake magnitude and epicentral distance on the performance and safety of semi-rigidly connected base-isolated steel framed buildings are studied. Suitable RBDO examples are solved to illustrate the results of investigations.

• Journal of the Ergonomics Society of Korea
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• v.32 no.1
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• pp.69-75
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• 2013

Objective: This study proposes an alarm display and compares it with the one(alarm tile display) widely used in main control rooms(MCRs) of nuclear power plants. Background: Catching up with the rapid development of computer technologies, advanced MCRs has been required. Using modern technologies of computers and visual displays, we have a lot of potential to improve user performance and satisfaction as well as safety in MCRs. Method: The alarm bar display has been proposed to reduce some potential problems of the alarm tile display in this study. Human factors evaluations were conducted to compare both types of displays. Two interfaces of bar alarm and tile alarm were simulated on the desktop computer for the user-involved experiment. Eight students participated in the experiment with the within-subject design. Results: The alarm bar was slightly better in terms of situation awareness, and preferred to understand alarm dynamics. The alarm tile was slightly or significantly better in other measures. Conclusion: Both alarm displays have their own advantages and disadvantages. Therefore, combining benefits of both displays can be used to optimize the design of alarm displays. Application: The proposed display is expected to compensate the existing displays for certain purposes.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.8
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• pp.1099-1110
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• 1998

The perceived quality is a concept considered from the consumer's perspective. So it is differ from the objective determination of product quality. Thus the consumer perception of quality is a subjective judgement of an individual and an overall feeling on the characteristics which includes the product's reliability, performance and so on. In terms of product perception, consumers utilize the product cues in evaluating the product's quality before the purchase and the cues reflecting the quality can be classifisied into intrinsic and extrinsic ones. When the quality perception is limited to the purchase situation, purchase decision dependent on surrogate indicators such as price, are inclined to increase due to the lack of information. Therefore in this study the perceived quality of apparel is controled to the purchase situation in order to examine the consumer's reaction to the price cues and for the convenience of the exploratory investigation. As a result of the empirical study, consumers show differences in quality and value perceptions to the product with the same price depending on the perception whether the price is high or low. The apparel quality evaluation process goes through the steps of "product attributes - perceived quality - perceived value - purchase intention".