• Journal of Korean Society of Steel Construction
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• v.29 no.5
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• pp.389-400
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• 2017

Based on U-shaped composite beam, the new form of AU-composite beam were developed to create economical and efficient components reducing the cost and shortening the length of construction work. Because the U-shaped sections are open and needs to be fixed by topping concrete securely. Therefore, it is required to maintain the U-shaped sections in a structure and to work in the safe condition through construction. It also requires accessories that resist the horizontal shear force for synthesis between the top and bottom of the U-shaped section. To reinforce these shortcomings, a shear connector has been developed with various purposes of steel plate anchors. In this study, the steel plate anchors were directly tested and the shear force was evaluated by the horizontal shear force. The experiment was divided into two types, depending on the applicable deck plates. As a result of the experiment, the continuous type specimens showed greater resistance in both strength and displacement than the ones of stud anchor specimen. In discontinuous type case, due to shear simulations and simple element analysis, the less increase the ratio of width to height and the more shear strength decreased. Thus, the shear strength equation of the stud anchor was modified to suggest the new shear strength based on the testing results.

• Journal of IKEEE
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• v.18 no.4
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• pp.593-602
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• 2014

One of the purposes of an artificial neural netowrk(ANNet) is to implement the largest number of functions as possible with the smallest number of nodes and layers. This paper presents a CoreNet which has a multi-leveled input value and a multi-leveled output value with a 2-layered ANNet, which is the basic structure of an ANNet. I have suggested an equation for calculating the capacity of the CoreNet, which has a p-leveled input and a q-leveled output, as $a_{p,q}={\frac{1}{2}}p(p-1)q^2-{\frac{1}{2}}(p-2)(3p-1)q+(p-1)(p-2)$. I've applied this CoreNet into the simulation model 1(5)-1(6), which has 5 levels of an input and 6 levels of an output with no hidden layers. The simulation result of this model gives, the maximum 219 convergences for the number of implementable functions using the cot(${\sqrt{x}}$) input leveling method. I have also shown that, the 27 functions are implementable by the calculation of weight values(w, ${\theta}$) with the multi-threshold lines in the weight space, which are diverged in the simulation results. Therefore the 246 functions are implementable in the 1(5)-1(6) model, and this coincides with the value from the above eqution $a_{5,6}(=246)$. I also show the implementable function numbering method in the weight space.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.599-605
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• 2012

The purpose of this study is to estimate diameter distribution, volume per hectare, and carbon stock for Quercus variabilis stand. 354 Quercus variabilis stands were selected on the basis of age and structure, the data and samples for these stands are collected. For the prediction of diameter distribution, Weibull model was applied and for the estimation of the parameters, a simplified method-of-moments was applied. To verify the accuracy of estimates, models were developed using 80% of the total data and validation was done on the remaining 20%. For the verification of the model, the fitness index, the root mean square error, and Kolmogorov-Smirnov statistics were used. The fitness index of the site index, height, and volume equation estimated from verification procedure were 0.967, 0.727, and 0.988 respectively and the root mean square error were 2.763, 1.817, and 0.007 respectively. The Kolmogorov-Smirnov test applied to Weibull function resulted in 75%. From the models developed in this research, the estimated volume and above-ground carbon stock were derived as $188.69m^3/ha$, 90.30 tC/ha when site index and stem number of 50-years-old Quercus variabilis stand show 14 and 697 respectively. The results obtained from this study may provide useful information about the growth of broad-leaf species and prediction of carbon stock for Quercus variabilis stand.

• Journal of the Korean GEO-environmental Society
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• v.15 no.9
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• pp.87-92
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• 2014

The Ground anchor is reinforcement to resist pull-out through ground that is used supports structure. The pull-out resistance of anchor is constructed by skin friction resistance from compression borehole wall in expanded wings and bearing pressure from the ground. Especially, underreamed ground anchor is reinforcement that adopts active reinforcement to prevent deformation of ground using bearing resistance generated reaming anchorage. This study is conducted to calculate bearing resistance of underreamed ground anchor. Realistic model tests were fulfilled to determine bearing resistance of anchor, and correlate results of tests to Uniaxial Compressive Strengths (UCS) of ground models that assumed weathered rock condition in 8 case. In a comprehensive series of the tests, the bearing resistances were measured by pull-out tests. The bearing resistances derived from tests have a linear correlation with UCS. We also suggest empirical equation between bearing resistance and UCS of rocks by single linear regression analyses. In test results of this study, the bearing resistances were evaluated approximately 13 times higher than UCS of the grounds, and it is qualitatively similar to numerical values of pull-out force derived from theory.

• Composites Research
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• v.23 no.4
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• pp.44-51
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• 2010

Recently, to solve the problems associated with the neutralization and corrosion of reinforced concrete compression members, the structural configurations such as CFFT (Concrete Filled GFRP Tube) and RCFFT (Reinforced Concrete Filled GFRR Tube) have been developed and applied to main members of civil engineering structure. These members can increase structural performance in terms of structural stability, ductility as well as chemical resistance compared with conventional concrete structural members. Many researches in numerous institutions to predict the load carrying capacity of the concrete compression member strengthened with FRP materials have been conducted and they have been suggested an equation for the prediction of the load carrying capacity of the members. Through the review of the research results, it was found that their results are similar each other. Moreover, it was also found that the results are not directly applicable to our specimens since the results are largely depended upon the member configurations. Also, since the accurate design criteria for the RC members strengthened with FRP such as RCFFT have not been established properly, relevant theoretical and experimental investigations must be conducted for the application to the practical structures. In this study, structural behavior of RCFFT was evaluated through compressive and quasi-static flexural tests in order to formulate design criteria for the structural design. In addition, the RCFFT members were also investigated to examine their confinement effect and the equations capable of estimating the compressive ultimate strength and flexural stiffness of the RCFFT members were proposed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1023-1035
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• 2016

Suspended sediment concentration (SSC) is a crucial riverine parameter in terms that it can be utilized for analyzing sediment transport, stability assessment of river and structure and so on. However, in case of domestic, sediment discharge data are not enough because of using conventional sediment samplers. This study aimed at developing a practical technique for estimating suspended sediment concentration in high spatial and temporal resolution by building relationship between acoustic backscatter (or SNR) from H-ADCP with actually observed data using LISST-100X. In this regard, a dedicated correction algorithm was proposed particularly for the adapted H-ADCP (SonTek SL-3000). Then, a SNR-SSC relation was built based upon a real-scale field experiment, where both H-ADCP and LISST-100X were concurrently operated to observe SNR and SSC, respectively. The coefficient of determination for the developed regression equation of SNR-SSC relation was around 0.85~0.88, thereby the relation could be evaluated to be highly correlated. The result of this study might be potentially applied for real-time and simultaneous observation of SSC when H-ADCP could be applied.

• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.187-197
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• 2011

There are many researches about effects of consumer innovativeness on the new product adoption behavior. However most of these studies regard this construct as one dimensional concept so that the extant studies suggest very ambiguous results about the relationship between consumer innovativeness and adoption behavior. This study subdivides the construct as cognitive innovativeness and sensory one and suggest these two types of consumer innovativeness affect on the risk perception of the potential adopter differently when the consumer adopt new product. In the empirical research through regression analysis and structure equation model with 217 samples, the study shows the consumer who have high level of cognitive innovativeness are more sensitive to functional risk of new products compared to one who have high level of sensory innovativeness. On the other side, sensory innovative consumer perceive social risk more when they adopt new products than cognitive innovator who have higher level of cognitive innovativeness. The result means there are dual paths on the relationship between consumer innovativeness and new products adoption behavior. Unlike the early studies, this study shows that there's dual path in relationship between the consumer's innovativeness and new product adoption. That is the consumer who have higher sensory innovativeness perceive the social risk of new products more sensitively than functional risk but the consumer who have cognitive innovativeness perceive functional risk more. So, new product adoption behavior would be different depending on the sensory or cognitive innovativeness.

• Journal of Distribution Science
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• v.14 no.12
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• pp.141-151
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• 2016

Purpose - Salesperson perceptions of the fairness and accuracy of a performance evaluation system were examined by managerial and professional employees of large organization. The performance evaluation process is central to many personal decisions such as attitude for job and sales performance. This study investigates the relationship between perceived evaluation fairness, job satisfaction, organizational commitment, and sales performance. The main purpose of this study is to develop and empirically test a comprehensive model of salespersons' perceived evaluation fairness on sales performance. For this purpose, we identified the structural relationship between perceived evaluation fairness, job satisfaction, organizational commitment, and sales performance. Also we investigate the mediating effects on job satisfaction and organizational commitment between perceived evaluation fairness and sales performance. Research design, data, and methodology - To empirically test these relationships, data were collected by in-depth interviews from sales managers and questionnaire surveys from 300 salespersons who work for sales area (credit card company, insurance company). Demographically, the overall sample was 91.6% female, 77.9% 30s and 40s, and 34% college educated, with an average tenure with their present organizations of 4 years. The questionnaire was composed of total 20 items dealing with frequency, quality, and consequences of perceived evaluation fairness, job satisfaction, organizational commitment, and sales performance. To test the research hypotheses, collected data analyzed by confirmatory factor analysis (CFA) and structure equation model (SEM). Results - Through extensive and rigorous literature review process of related literature(Perceived evaluation fairness, Job satisfaction, Organizational commitment, Sales performance), research model and research hypothesis was set up. This study obtains the following research results. First, perceived evaluation fairness has a positive effect on job satisfaction, whereas the effects of perceived evaluation fairness on organizational commitment and sales performance did not show statistically significant result. Second, job satisfaction and organizational commitment have complete mediating roles to the relationship between perceived evaluation fairness and organizational commitment, and relationship between perceived evaluation fairness and sales performance. Conclusions - Based on the results, salespersons' perceived evaluation fairness is one of the key independent variable for making high job satisfaction, organizational commitment, and sales performance. Finally the theoretical, managerial implication and research limitations are mentioned in the discussion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.479-485
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• 2006

The double gate(DG) MOSFET is a promising candidate to further extend the CMOS scaling and provide better control of short channel effect(SCE). DGMOSFETs, having ultra thin undoped Si channel for SCEs control, ale being validated for sub-20nm scaling. A novel analytical transport model for the subthreshold mode of DGMOSFETs is proposed in this paper. The model enables analysis of short channel effect such as the subthreshold swing(SS), the threshold voltage roil-off$({\Delta}V_{th})$ and the drain induced barrier lowering(DIBL). The proposed model includes the effects of thermionic emission and quantum tunneling of carriers through the source-drain barrier. An approximative solution of the 2D Poisson equation is used for the distribution of electric potential, and Wentzel-Kramers-Brillouin approximation is used for the tunneling probability. The new model is used to investigate the subthreshold characteristics of a double gate MOSFET having the gate length in the nanometer range $(5-20{\sim}nm)$ with ultra thin gate oxide and channel thickness. The model is verified by comparing the subthreshold swing and the threshold voltage roll-off with 2D numerical simulations. The proposed model is used to design contours for gate length, channel thickness, and gate oxide thickness.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.703-707
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• 2009

In order to evaluate applicability of cylindrical slit type block breakwater to the field water, which was designed from the previous physical model study, it is analyzed the calmness of harbor area by the numerical model experiment. For a small fishery port in southern coast of Korea a SWAN model using the wave action balance equation was formulated. The reflection and transmission coefficients induced by the physical model test were introduced to the numerical model. The model response with cylindrical slit type breakwater was compared with the impermeable breakwater case and the possibility of water quality improvement through the water circulation by the new structure was investigated. For numerical simulation, parameters of deepwater design wave from the prediction report II for overall deepwater design wave by KORDI were used and wind parameters from the 50years return period observed for 37years(1970~2006) were adopted in the numerical model. The response of west breakwater in Mijo port applying the NE and NNE waves, which were dominant in this area, was analyzed. It was found that the transmission characteristic of designed cylindrical slit breakwater was well presented in the numerical model.