• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.772-779
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• 2005

The objectives of this study were to examine problems with using F$_1$ data by simulation, association of marker loci and QTL from crosses of inbred parental lines and to enumerate the preliminary characterization of genetic superiority within inbred parental lines. In this study, the association between markers for QTL used as covariates and estimates of variance components due to effects of lines was investigated through computer simulation. The effects of size of population to develop inbred lines and initial frequencies and magnitudes of effects of QTL were also considered. Results show that estimates of variance components due to line effects are influenced by including marker information as covariates in the model for analysis. Estimates of line variance were increased by adding marker information into the analysis, because negative covariances between effects associated with the markers and the remaining effects associated with other loci existed. However, the fit of the model as indicated by the log likelihood improved by adding more markers as covariates into the analysis. Marker assisted selection will be beneficial when markers explain unexplained genetic difference during selection procedure. Markers can be used to identify QTLs affecting traits, and to select for favorable QTL alleles. To efficiently use genetic markers, location of markers at the genome must be identified. The estimates of variance due to effects of with and without marker information used as covariates in the analysis were investigated. The estimates of line variances were always increased when markers were included as covariates for the model because a negative covariance were existed.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.69-75
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• 2015

PURPOSES : The objective of this study is to evaluate the effectiveness of a geogrid reinforced subbase of permeable flexible pavement structures with respect to permanent deformation. METHODS : Experimental trials employing a repeated triaxial load test scheme were conducted for both a geogrid reinforced subbase material and a control specimen to obtain the permanent deformation properties based on the VESYS model. Along with this, a finite element-based numerical analysis was conducted to predict pavement performance with respect to the rutting model incorporated into the analysis. RESULTSAND CONCLUSIONS : The results of the experimental study reveal that the geogrid reinforcement seems to be effective in mitigating permanent deformation of the subbase material. The permanent deformation was mostly achieved in the early stages of loading and then rapidly reached equilibrium as the number of load applications increased. The ultimate permanent deformation due to the geogrid reinforcement was about 1.5 times less than that of the control specimen. Numerical analysis showed that the permeable, flexible pavement structure with the geogrid reinforced subbase also exhibits less development of rutting throughout the service life. This reduction in rutting led to a 20% decrease in thickness of the subbase layer, which might be beneficial to reduce construction costs unless the structural adequacy is not ensured. In the near future, further verification must be conducted, both experimentally and numerically, to support these findings.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.7
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• pp.22-34
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• 2020

Three-dimensional (3D) computer-aided design (CAD) models require different levels of detail (LODs) depending on their purpose. Therefore, it is beneficial to automatically simplify 3D CAD assembly models to meet the desired LOD. Feature-based 3D CAD assembly models typically have the lowest and highest feasible limits of LOD during simplification. In order to help users obtain a feasible simplification result, we propose a method to simplify feature-based 3D CAD assembly models by determining the lowest and highest limits of LOD. The proposed method is verified through experiments using a simplification prototype implemented as a plug-in type module on Siemens NX.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.403-412
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• 2018

In this study, a three-dimensional variational(3DVAR) data assimilation system was developed for the operational numerical weather prediction(NWP) system at the Republic of Korea Air Force Weather Group. The Air Force NWP system utilizes the Weather Research and Forecasting(WRF) meso-scale regional model to provide weather information for the military service. Thus, the data assimilation system was developed based on the WRF model. Experiments were conducted to identify the nested model domain to assimilate observations and the period appropriate in estimating the background error covariance(BEC) in 3DVAR. The assimilation of observations in domain 2 is beneficial to improve 24-h forecasts in domain 3. The 24-h forecast performance does not change much depending on the estimation period of the BEC in 3DVAR. The results of this study provide a basis to establish the operational data assimilation system for the Republic of Korea Air Force Weather Group.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.401-406
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• 2001

When propagating the thickness direction of composite laminates ultrasound waves interacts strongly with the orientation and sequence of the plies in a layup. Also the layup orientation greatly influences its properties in a composite laminate. If one ply of the layup orientation is misaligned, it could result in the part being rejected and discarded. Now, most researchers cut a small coupon from the waste edge and use a microscope to optically verify the ply sequences on important parts. Those may add a substantial cost to the product since the test is both labor hard and performed after the part is cured. A nondestructive technique would be very beneficial, which could be used to test the part after curing and require less time than the optical test. Therefore we have developed, reduced, and implemented a novel ply-by-ply vector decomposition model for composite lam mates fabricated from unidirectional plies. This model decomposes the transmission of a linearly polarized ultrasound wave into orthogonal components through each ply of a laminate. It is found that a high probability shows between the model and tests developed in characterizing cured layups of the laminates.

• Atmosphere
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• v.30 no.2
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• pp.103-113
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• 2020

In this study, we analyzed and developed the monitoring system in order to confirm the effect of observations on forecast sensitivity on ensemble-based data assimilation. For this purpose, we developed the Ensemble Forecast Sensitivity to observation (EFSO) monitoring system based on Local Ensemble Transform Kalman Filter (LETKF) system coupled with Korean Integrated Model (KIM). We calculated 24 h error variance of each of observations and then classified as beneficial or detrimental effects. In details, the relative rankings were according to their magnitude and analyzed the forecast sensitivity by region for north, south hemisphere and tropics. We performed cycle experiment in order to confirm the EFSO result whether reliable or not. According to the evaluation of the EFSO monitoring, GPSRO was classified as detrimental observation during the specified period and reanalyzed by data-denial experiment. Data-denial experiment means that we detect detrimental observation using the EFSO and then repeat the analysis and forecast without using the detrimental observations. The accuracy of forecast in the denial of detrimental GPSRO observation is better than that in the default experiment using all of the GPSRO observation. It means that forecast skill score can be improved by not assimilating observation classified as detrimental one by the EFSO monitoring system.

• Journal of Veterinary Clinics
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• v.35 no.3
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• pp.83-87
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• 2018

The aim of this study was to evaluate the biomechanical behavior of xenogenic bone plate system (equine bone) using a three-dimensional finite element ulna fracture model. The model was used to calculate the Von Mises stress (VMS) and stress distribution in fracture healing periods with metallic bone plate and xenogenic bone plate systems, which are installed while the canine patient is standing. Bone healing rate (BHR) (0%) and maximum VMS of the xenogenic plate was similar to the yield strength of equine bone (125 MPa). VMS at the ulna and fracture zones were higher with the xenogenic bone plate than with the metallic bone plate at BHRs of 0% and 1%. Stress distributions in fracture zone were higher with the xenogenic bone plate than the metallic bone plate. This study results indicate that the xenogenic bone plate may be considered more beneficial for callus formation and bone healing than the metallic bon plate. Xeonogenic bone plate and screw applied in clinical treatment of canines may provide reduced stress shielding of fractures during healing.

• Journal of Information Technology Applications and Management
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• v.21 no.2
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• pp.49-79
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• 2014

The adoption of technology has always been of interest to academicians and practitioners of the field of Management Information System. This is so because without proper and adequate adoption, technology-no matter how beneficial or advanced it may be-will be of little value to users. Numerous researches, such as the researches of the Technology Acceptance Model (TAM) or the Unified Theory of Acceptance and Use of Technology (UTAUT), had been conducted to understand the human nature in association with the adoption or rejection of technologies that have bombarded the users. The coming of smart technologies (i.e., smart phones and devices), however, seems to have fundamentally changed the environment for adoption. The ubiquity combined with mobility of technology, especially when it comes to mobile apps, seem to make the old PC era of two-stage-pre and post-adoption models obsolete. A new model of adoption that identifies the determinants of technology acceptance and continuance is needed for the smart age. To this end, this paper undertakes an empirical study, by analyzing 229 users of Social Networking Service (SNS) mobile apps, to identify the role of user experience on the multi-stage adoption of technology, and provides results that User Experience (UX) plays the crucial role of bridging the separate stages of pre and post adoption of technologies. The paper concludes by providing practical implications of the new model as it relates to mobile apps and technologies, and recommendations for further studies to get a better understanding of technology adoption in the smart age.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.170-180
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• 2000

The surface-drainage system, which consists of bio-swale and detention-infiltration Basins and carries out the function of temporary detention-infiltration of runoff, is defined as the "natural drainage system". It is an environmentally sound and economically beneficial practice to reduce run-off by retaining it in swales as much as possible and letting run-off infiltrate into the ground. In order to estimate appropriate capacity of swales, it is necessary to know how long will it take for certain depths of water to infiltrate. The ponding times, or infiltration times, of various depths and of various soil textures, could be estimated with the Green-Ampt Infiltration Model. Included soil textures are loamy sand, sandy loam, loam, silty loam, sandy clay loam and clay loam. Ponding depths are from 10cm to 100cm intervals. Newton-Raphson method is used for the solution of the Green-Ampt equation by a computer program. The computer program was written with the FORTRAN Developer 4.0 v.. Selected ponding depth is acceptable when the sum of the ponding time and the breeding time of mosquitoes is less than the tolerance period of innundation of grasses and trees.and trees.

• Geomechanics and Engineering
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• v.21 no.1
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• pp.73-84
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• 2020

In the seismic design of bridges, formation of plastic hinges plays an important role in the dissipation of seismic energy. In the case of conventional fixed-base bridges, the plastic hinges are allowed to form in the superstructure alone. During seismic event, such bridges may be safe from collapse but the superstructure undergoes significant plastic deformations. As an alternative design approach, the plastic hinges are guided to form in the soil thereby utilizing the inevitable yielding of the soil. Rocking foundations work on this concept. The formation of plastic hinges in the soil reduces the load and displacement demands on the superstructure. This study aims at evaluating the seismic response of bridge pier supported on rocking shallow foundation. For this purpose, a BNWF model is implemented in OpenSees platform. The capability of the BNWF model to capture the SSI effects, nonlinear behavior and dynamic loading response are validated using the centrifuge and shake table test results. A comparative study is performed between the seismic response of the bridge pier supported on the rocking shallow foundation and conventional fixed-base foundation. Results of the study have established the beneficial effects of using the rocking shallow foundation for the seismic response analysis of the bridge piers.