• Steel and Composite Structures
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• v.46 no.6
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• pp.839-856
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• 2023

This work presents a simple four-unknown refined integral plate theory for mechanical and thermal buckling behaviors of functionally graded (FG) plates resting on Visco-Pasternak foundations. The proposed refined high order shear deformation theory has a new displacement field which includes indeterminate integral variables and contains only four unknowns in which any shear correction factor not used, with even less than the conventional theory of first shear strain (FSDT). Governing equations are deduced from the principle of minimum total potential energy and a Navier type analytical solution is adopted for simply supported FG plates. The Visco-Pasternak foundations is considered by adding the impact of damping to the usual foundation model which characterized by the linear Winkler's modulus and Pasternak's foundation modulus. The accuracy of the present model is demonstrated by comparing the computed results with those available in the literature. Some numerical results are presented to show the impact of material index, elastic foundation type, and damping coefficient of the foundation, on the mechanical and thermal buckling behaviors of FG plates.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.4
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• pp.1-10
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• 2023

As a result of climate change, non-point source pollution (NPS) from farmland with the steep slope during the rainy season is expected to have a significant impact on the water system. This study aimed to evaluate the effect of furrow mulching using alfalfa and PAM (Polyacrylamide) materials for each rainfall event, while considering the load characteristics of NPS. The study was conducted in Wanju-gun, Jeollabuk-do, in 2022, with a testbed that had a slope of 13%, sandy loam soil, and maize crops. The testbed was composed of four plots: bare soil (Bare), No mulching (Cont.), Vegetation mulching (VM), and PAM mulching (PM). Runoff was collected from each rainfall event using a 1/40 sampler and the NPS load was calculated by measuring the concentrations of SS, T-N, T-P, and TOC. During farming season, the reduction efficiency of NPS load was 37.1~59.5% for VM and 38.2~75.7% for PM. The analysis found that VM had a linear regression correlation (R²=0.28~0.86, P-value=0.01~0.1) with elapsed time of application, while PM had a quadratic regression correlation (R²=0.35~0.80, P-value=0.1). These results suggest that the selection of furrow mulch materials and the appropriate application method play a crucial role in reducing non-point pollution in farmland. Therefore, further studies on the time-series reduction effect based on the application method are recommended to develop more effective preemptive reduction technologies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3B
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• pp.241-251
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• 2006

This study analyzed the topographical characteristics by extracting property factors of stream (stream order, number of stream, stream length, mean stream length) and property factors of basin (basin area, basin length, total stream length, total number of stream, basin mean width, form factor, maximum stream order, basin density, stream frequency, relief ratio, mean elevation, mean, slope, maximum elevation) from DEM (digital elevation model) and stream network generated by 1:5,000 NGIS (national geographical information system) data for the Bukhan-river basin. In addition, topographical factors for upper, mid stream and lower stream were analyzed and the mutuality of the factors by linear and nonlinear regression curve was identified.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3A
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• pp.189-197
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• 2009

In this study, truck weight data and load effects of single truck on bridges are analyzed for development of new vehicular load model of the reliability-based bridge design code. Rational load model and statistical properties of loads are important for developing reliability-based design code. In this study, truck weight data collected at four locations are used as well as data from four locations in other studies. Truck weight data are collected from WIM or BWIM system, which are known to give reliable data. Typical truck types, dimensions and axle weight distribution are determined. Probability distributions of upper 20% total truck weight are assumed as Extreme Type I and 100 years maximum truck weights are estimated by linear regression on the probability paper. The load effects of trucks having estimated maximum weights are analyzed for span length from 10 m to 200 m.

• International Journal of Computer Science & Network Security
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• v.23 no.7
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• pp.1-8
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• 2023

An Orthogonal Frequency Division Multiplexing (OFDM) based wireless communication system has drawn wide attention for its high transmission rate and high spectrum efficiency in not only radio but also Underwater Acoustic (UWA) applications. Because of the narrow sub-carrier spacing of OFDM, orthogonality between sub-carriers is easily affected by Doppler effect caused by the movement of transmitter or receiver. Previously, Doppler compensation signal processing algorithm for Desired propagation path was proposed. However, other Doppler shifts caused by delayed Undesired signal arriving from different directions cannot be perfectly compensated. Then Receiver Bit Error Rate (BER) is degraded by Inter-Carrier-Interference (ICI) caused in the case of Multi-path Doppler channel. To mitigate the ICI effect, a modified Delay and Doppler Profiler (mDDP), which estimates not only attenuation, relative delay and Doppler shift but also sampling clock shift of each multi-path component, is proposed. Based on the outputs of mDDP, an ICI canceling multi-tap equalizer is also proposed. Computer simulated performances of one-tap equalizer with the conventional Time domain linear interpolated Channel Transfer Function (CTF) estimator, multi-tap equalizer based on mDDP are compared. According to the simulation results, BER improvement has been observed. Especially, in the condition of 16QAM modulation, transmitting vessel speed of 6m/s, two-path multipath channel with direct path and ocean surface reflection path; more than one order of magnitude BER reduction has been observed at CNR=30dB.

• Journal of English Language & Literature
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• v.58 no.6
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• pp.1001-1021
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• 2012

This paper is concerned with John Ashbery's poetics of difficulty, questioning in particular the nature of communication in his difficult poems. Ashbery has an idea of poetry as 'information' to be transmitted to the reader. Meaning, however, is to be created by a series of selections among equally probable choices. Ashbery's poetry has been characterized by resistance to the interpretive system of meaning. But the resistance itself, as I will argue, can be an effective medium of communication as the communicated message is not simply transmitted but 'selected' and thus created by the reader. In Ashbery's poetry, disruptive 'noise' elements can be processed as constructive information. What is normally considered a hindrance or noise can be reversed and added to the information. In Ashbery's poems, random ambiguities or noises can be effectively integrated into the final structure of meaning. Such a stochastic sense of information transfer has been embodied in Ashbery's idea of creating a network of verbal elements in his poetry, analogous to the interconnecting web of hypertext, the most dynamic medium 'information technology' has brought to us. John Ashbery, whose poems are simultaneously incomprehensible and intelligent, employs ambiguities or noise in his poetry, with an attempt to reach through linear language to express nonlinear realities. It is therefore my intention to examine Ashbery's poetics of difficulty, from a perspective of communication transmission, using the theories of information technology and the principles of hypertext theory. Ashbery's poetry raises precisely the problem confronted in the era of communication and information technology. The paper will also show how his aesthetics of difficulty reflects the culture of our uncertain times with overflowing information. With his difficult enigmatic poems, Ashbery was able to move ahead of the technological advances of his time to propose a new way of perceiving the world and life.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.459-461
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• 2022

One of the big differences between Network-on-Chip (NoC) and the existing parallel processing system based on an off-chip network is that data packet routing is performed using a centralized control scheme. In such an environment, the best-effort packet routing problem becomes a real-time assignment problem in which data packet arriving time and processing time is the cost. In this paper, the Hungarian algorithm, a representative computational complexity reduction algorithm for the linear algebraic equation of the allocation problem, is implemented in the form of a hardware accelerator. As a result of logic synthesis using the TSMC 0.18um standard cell library, the area of the circuit designed through case analysis for the cost distribution is reduced by about 16% and the propagation delay of it is reduced by about 52%, compared to the circuit implementing the original operation sequence of the Hungarian algorithm.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.484-492
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• 2023

The structural behaviour of concrete beam was examined by the three points bending test after the completion of the electrochemical chloride extraction (ECE), rather than bond strength mostly measured in previous studies. It was found that the flexural rigidity of concrete was lowered by the ECE, but the strength was enhanced in terms of the maximum load.The flexural rigidity, in the linear elastic range, was reduced by the loss of effective cross-section area. In fact, the inertia moment was substantially subjected to 70 % loss of the cross-section by the tensile strain at the condition of the failure. However, a lower rate of the inertia moment reduction was achieved by the ECE, implying the higher resistance to the cracking, but the higher risk of deformation.

• The Korean Journal of Applied Statistics
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• v.36 no.5
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• pp.489-499
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• 2023

As sharing of analyst reports became widely available, reports generated by analysts have become a useful tool to reduce difference in financial information between market participants. The quantitative information of analyst reports has been used in many ways to predict stock returns. However, there are relatively few domestic studies on the prediction power of text information in analyst reports to predict stock returns. We test stock return predictability of text in analyst reports by creating variables representing the TONE from the text. To overcome the limitation of the linear-model-assumption-based approach, we use the random-forest-based F-test.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.39-52
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• 2023

In this study, project information of government-funded research institute in the food field was collected and analyzed to systematically identify the factors affecting the process of transferring technological achievements of public research institute to the private sector. This study hypothesized that human resources, financial resources, and technological characteristics as input factors of R&D projects affect output factors, such as research papers or patents produced by R&D projects. Moreover, these outputs would serve as drivers of the technology transfer as one of the R&D outcomes. Linear Regression Analysis and Poisson Regression Analysis were conducted to empirically and sequentially investigate the relationship between input factors and output and outcome of R&D projects and the results are as follows: First, the principle investigator's career and participating researcher's size as human resource factors have an influence on both the number of SCI (science citation index) papers and patent registration. Second, the research duration and research expenses for the current year have an influence on the number of SCI papers and patent registrations, which are the main outputs of R&D projects. Third, the technology life cycle affects the number of SCI papers and patent registrations. Lastly, the higher the number of SCI papers and patent registrations, the more it affected the number of technology transfers and the amount of technology transfer contract.