• Journal of the Korean Ceramic Society
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• v.36 no.10
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• pp.1132-1138
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• 1999

• Smart Structures and Systems
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• v.15 no.3
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• pp.505-522
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• 2015

Variation of temperature is a primary environmental factor that affects the behavior of structures. Therefore, understanding the mechanisms of normal temperature-induced variations of structural behavior would help in distinguishing them from anomalies. In this study, we used the structural health monitoring data of the Shanghai Yangtze River Bridge, a steel girder cable-stayed bridge, to investigate the mechanisms of thermally induced vertical deflection ($D_T$) at mid-span of such bridges. The $D_T$ results from a multisource combination of thermal expansion effects of the cable temperature ($T_{Cab}$), girder temperature ($T_{Gir}$), girder differential temperature ($T_{Dif}$), and tower temperature ($T_{Tow}$). It could be approximated by multiple linear superpositions under operational conditions. The sensitivities of $D_T$ of the Shanghai Yangtze River Bridge to the above temperatures were in the following order: $T_{Cab}$ > $T_{Gir}$ > $T_{Tow}$ > $T_{Dif}$. However, the direction of the effect of $T_{Cab}$ was observed to be opposite to that of the other three temperatures, and the magnitudes of the effects of $T_{Cab}$ and $T_{Gir}$ were found to be almost one order greater than those of $T_{Dif}$ and $T_{Tow}$. The mechanisms of the thermally induced vertical deflection variation at mid-span of a cable-stayed bridge as well as the analytical methodology adopted in this study could be applicable for other long-span cable-stayed bridges.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.96-106
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• 1995

오늘날의 화훼산업에 있어 생산물의 품질을 결정짓는 요인은 여러 측면에서 생각해 볼 수 있겠지만, 생산자적 측면에서는 화색, 화형, 일률적인 초장 등이 무엇보다 중요하다고 판단된다 최근 화훼산업이 단일종으로 대형화, 전문화되어 감에 따라 하우스 내에서 생장을 조절하여 상품을 획일화 균일화시키고, 출하날짜 등을 맞추기 위한 여러 종류의 기술들이 필요해지고 있다.(중략)

• Computers and Concrete
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• v.26 no.3
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• pp.227-237
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• 2020

Strain rate investigations are needed to calibrate strain-rate-dependent material models and numerical codes. An appropriate material model, which considers the rate effects, need to be used for proper numerical modeling. The plastic concrete cut-off wall is a special underground structure that acts as a barrier to stop or reduce the groundwater flow. These structures might be subjected to different dynamic loads, especially earthquake. Deformability of a structure subjected to dynamic loads is a principal issue which need to be undertaken during the design phase of these structures. The characterization of plastic concrete behavior under different strain rates is essential for proper designing of cut-off walls subjected to dynamic loads. The Cowper-Symonds model, as one of the most commonly applied material models, complies well with the behavior of a plastic concretes in low to moderate strain rates and will be useful in explicit dynamics simulations. This paper aims to present the results of an experimental study on mechanical responses of one of the most useful types of plastic concrete and Cowper-Symonds constant determination procedures in a wide range of strain rate from 0.0005 to 107 (1/s). For this purpose, SHPB, uniaxial, and triaxial compression tests were done on plastic concrete samples. Based on the results of quasi-static and dynamic tests, the dynamic increase factors (DIF) of this material in different strain rates and stress state conditions were determined for calibration of the Cowper - Symonds material models.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1488-1493
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• 2019

The rising cases of multidrug-resistant Acinetobacter baumannii (Ab) and the lack of effective drugs call for quick attention. Here, based on a Tn7 transposon and Xer/dif system, we constructed a stable, selectable marker-free autoluminescent Ab capable of producing visible light without extra substrates. Utilization of this autoluminescent reporter strain has the potential to reduce the time, effort and costs required for the evaluation of activities of anti-Ab drug candidates in vitro.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.131-135
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• 1995

In winter, most of the energy for a greenhouse crop is supplied during the night. Since watermelon is grown under high night temperature, the experiments were set up to investigate night temperature influence on watermelon in order to obtain the best economic output. Day temperatures ranged from $25^{\circ}C$ and 3$0^{\circ}C$ ; night temperatures ranged from 2$0^{\circ}C$ to 3$0^{\circ}C$ at 5$^{\circ}C$ interval. Two cultivars of watermelon(Citrullus vulgaris S. ‘Binna’ and ‘Kamro’) treated with 30/3$0^{\circ}C$ yielded maximum leaf areas, flowers and leaf numbers. 30(14h)/25(10h)$^{\circ}C$ or 30(12h)/25(12h)$^{\circ}C$ grown plants had higher germination ratio and more dry weight and chlorophyll than those of 30/3$0^{\circ}C$ which were the highest temperature integral. Although 25/$25^{\circ}C$ and 30/2$0^{\circ}C$ regime are same average temperature, the growth of watermelons at 30/2$0^{\circ}C$ was significantly higher than 25/$25^{\circ}C$. ‘Binna’ was growing more than ‘Kamro’ at the same temperature. Leaf area ratio(LAR) was reduced with increasing DIF temperature from 30/3$0^{\circ}C$ to 30/2$0^{\circ}C$, but leaf weight ratio(LWR) was increased.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.6
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• pp.557-564
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• 2007

The effect of wave and current interactions on regular wave transformation over a submerged elliptic shoal is investigated based on numerical simulations of the Vincent and Briggs experiment [Vincent, C.L., Briggs, M.J., 1989. Refraction-diffraction of irregular waves over a mound. Journal of Waterway, Port, Coastal and Ocean Engineering, 115(2), pp. 269-284]. The numerical simulations are conducted by constituting two numerical model systems: a combination of SWAN(a wave model) plus SHORECIRC(a current model) and a combination of REF/DIF 1(a wave model) plus SHORECIRC. A time dependent phase-resolving wave-current model, FUNWAVE, is also utilized to simulate the experiment. In the simulations, the breaking-induced currents defocus waves behind the shoal and bring on a wave shadow zone that shows relatively low wave height distributions. The computed results of the two model systems agree better with the measurements than the computed results obtained by neglecting wave-current interaction do. However, it is found that the radiation stresses for standing waves are misevaluated in the wave models. In addition, the results of FUNWAVE show very good agreement with the measurements. The agreement indicates that it is necessary to take into account the effect of breaking-induced current on wave refraction when wave-breaking occurs over a submerged shoal.

• Therapeutic Science for Rehabilitation
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• v.11 no.3
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• pp.65-80
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• 2022

Objective : This study examined the psychometric properties of the 12-item Coping Orientation to Problems Experienced Scale (COPE) using Rasch analysis. COPE is one of the instruments used to measure stress-coping skills. Methods : The study participants were 480 community-dwelling older adults. We tested the instrument's unidimensionality assumption using principal component analysis (PCA). Item fit was examined using infit-and-outfit mean-square (MnSq) and standardized fit statistics (ZSTD). The precision and item difficulty hierarchies of the instrument were examined. The item-difficulty hierarchy was investigated to identify the easy and difficult items. We tested differential item functioning (DIF) for sex and age groups. Results : PCA revealed that the instrument met the unidimensionality assumption (eigenvalue = 1.78). Among the 12 items, item 2 was removed because of misfit (Infit MnSq = 1.33, Infit ZSTD = 5.05, Outfit MnSq = 1.56, Outfit ZSTD = 7.15). The remaining 11 items demonstrated a conceptual item-difficulty hierarchy. The person strata value was 3.10, which is equivalent to a reliability index value of 0.81. There was no DIF for the sex and age groups (DIF contrast <0.27). Conclusion : The findings indicated that the revised COPE-11 has adequate item-level psychometric properties and can accurately measure stress coping skills.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.444-446
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• 1994

This paper describes the design of a digital multifunction controller for the intelligent high voltage customer switchboard and proposes a relaying algorithm for high impedance faults using back-propagation neural network. The hardware design uses the three microprocessors and global memory architecture to achive real time operation and control 4 feeders. The controller uses a 64-point radix-4 DIF FFT algorithm to measure the harmonic and relay parameters. Synthesized fault current waveforms are used to train and test the back - propagation network.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.11a
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• pp.58-61
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• 2004