• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4411-4417
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• 2012

The present study proposes the optimization of wing structure base on reduced model which assures the solution accuracy and computational efficiency. Well-constructed reduced model assures the accurate result in the eigenvalue problem, dynamic analysis or sensitivity of design optimization. Reduced system is classified into the reduce-order model based on structural modes and the reduced system based on degrees of freedom. Because this study uses the reduced system based on degrees of freedom, it is important to select the dominant degrees of freedom properly. For this work, robust selection method, two-level selection scheme, is employed and IRS(Improved Reduced System) is applied to construct the final reduced system. In the optimization process based on the reduced system, all of the equivalent stress, eigenvalue and design sensitivities are calculated from the reduced system. Through a numerical example, it is shown that the present optimization methodology based on the reduction method can provide an optimal results for objective function satisfying constraint condition.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.8 no.2
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• pp.131-139
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• 2013

Objectives : The purpose of this study is to investigate the efficacy of conservative treatment on Achondroplasia patient who has low back pain with radiation. Methods : The patient was treated by conservative treatment including acupuncture, pharmaco acupuncture, chu-na manipulation, herbal medicine. Numeric rating scale(NRS), Oswestry disability index(ODI) were used to evaluate pain reduction. Physical examination also used to compare with admission state and discharge state. Results : After 1 month admission treatment, NRS decreased 9 to 6, ODI dcreased 56 to 42, ROM improved as normal person. Conclusions : It was efficient that Achondroplasia patient who has low back pain with radiation treated as conservative treatment including acupuncture, pharmaco acupuncture, chu-na manipulation, herbal medicine. But It was just one case and treatments were carried out in Integrative Package. So further studies are required to compare that which treatment is efficient.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.273-276
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• 1996

In the Total Artificial Heart (TAH) and Ventricular Assist Device (VAD), the size implanting the internal controller into human body is very serious problem. Hence, we need the size reduction of that controller for safe implantation. Using PSD302 chip for microcontroller-based applications, we could decrease the number of components in the digital control board and miniaturize the digital control board. We could replace a ROM, RAM, and a latch with that single chip, so the size of the newly developed board could be half the previous board.

• Journal of Information Technology Applications and Management
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• v.29 no.1
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• pp.47-57
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• 2022

The purpose of this study is to analyze the current status of augmented reality picture books, which have been steadily developed since 2010, as a genre of electronic picture books, and to reveal how children's immersion in augmented reality picture books differs from paper picture books. To this end, 30 augmented reality picture books on the market were analyzed according to genre, life theme, implementation method, and augmented reality scene ratio. As a result of the study, it was found that the genre of picture books was in the order of information fairy tales, daily fairy tales, and historical fairy tales, and there were no traditional or fantasy fairy tales. Animals and plants accounted for about half of the life topics, and in some cases, there were only a few or no other life topics. In the augmented reality implementation scene, it consisted of only one page in the early days, but all pages are now possible to implement augmented reality due to technology development, production cost reduction, and improved hardware performance of smartphones. It was found that the augmented reality implementation method used CD-ROM in the early days, but gradually became possible to implement using only mobile phones and tablets that were easy for readers to access. In addition, after presenting four picture books to eight 5-year-old infants, the immersion time was measured and the immersion behavior was observed. As a result, augmented reality picture books showed higher immersion[immersion time, immersion behavior] than paper picture books, but compared by literature genre, life fairy tales were higher in paper picture books and natural fairy tales in augmented reality picture books. It was higher when presenting augmented reality picture books after presenting paper picture books according to the order of presentation of picture book types. The results of this study suggest that more diverse life topics and augmented reality picture books in the genre of children's literature should be developed to increase the utilization of augmented reality picture books. In addition, considering that there are differences in immersion between types, literary genres, and reading experience [presentation order], it is expected to increase the educational effect by using picture books complementarily.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.434-439
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• 2013

This study was conducted to compare the dental plaque reduction using various mouthwashes with Quantitative Light induced Fluorescence-Digital (QLF-D). A survey on 20 students was carried out. The students who were at Shingu College. Experimental group was gargled 20 ml of Listerine during 30 seconds and 15 ml of Hexamedine during 60 seconds. Control group was gargled distilled water during 30 second. The data were analyzed with t-test using SPSS 20.0 program. The ratios of control group and experimental group were reduced. Degree of ${\Delta}R30$ and ${\Delta}R70$ Listerine group was a significant difference (p>0.05). Degree of Simple Plaque Score and ${\Delta}R30$ Hexamedine group was a significant difference (p>0.05). There was no significant difference in the distilled water gargle group (p<0.05). The result of this study has the effect of two mouthwashes reduced dental plaque. The evaluation data of this study will be used in clinical application and research about QLF-D.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.555-565
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• 2006

The purpose of the present study is to evaluate the biological stability of the zirconia/alumina composite abutment by histologic and radiographic examination in clinical cases. 17 partially edentulous patients (5 men and 12 women, mean age 47) were treated with 37 implants. The implants were placed following the standard two-stage protocol. After a healing period of 3 to 6 months, zirconia/alumina composite abutments were connected. All radiographs were taken using paralleling technique with individually fabricated impression bite block, following insertion of the prosthesis and at the 3-, 6-, 12 month re-examinations. After processing the obtained images, the osseous level was calculated using the digital image in the mesial and distal aspect in each implant. An ANOVA and t-test were used to test for difference between the baseline and 3-, 6-, 12 months re-examinations, and for difference between maxilla and mandible. Differences at P <0.05 were considered statistically significant. For histologic examination, sample was obtained from the palatal gingiva which implant functioned for 12 months. Sections were examined under a light microscope under various magnifications. Clinically, no abutment fracture or crack as well as periimplantitis was observed during the period of study. The mean bone level reduction(${\pm}standard$ deviation) was 0.34 rom(${\pm}\;0.26$) at 3-months, 0.4 2mm(${\pm}\;0.30$) at 6-months, 0.62 mm(${\pm}\;0.28$) at 12-months respectively. No statistically significant difference was found between baseline and 3-, 6-, 12-months re-examinations (p > 0.05). The mean bone level reduction in maxilla was 0.33(${\pm}0.25$) at 3-months, 0.36(${\pm}0.33$) at 6-months, 0.56(${\pm}0.26$) at 12-months. And the mean bone level reduction in mandible was 0.35(${\pm}0.27$) at 3-months, 0,49(${\pm}0.27$) at 6-months, 0.68(${\pm}0.30$) at 12-months. No statistical difference in bone level reduction between implants placed in the maxilla and mandible. Histologically, the height of the junctional epithelium was about 2.09 mm. And the width was about 0.51 mm. Scattered fibroblasts and inflammatory cells, and dense collagen network with few vascular structures characterized the portion of connective tissue. The inflammatory cell infiltration was observed just beneath the apical end of junctional epithelium and the area of direct in contact with zirconia/alumina abutment. These results suggest the zirconia/alumina composite abutment can be used in variable intraoral condition, in posterior segment as well as anterior segment without adverse effects.

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.138-147
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• 2018

Purpose: A narrowband hyperspectral imaging sensor of high-dimensional spectral bands is advantageous for identifying the reflectance by selecting the significant spectral bands for predicting crop yield over the broadband multispectral imaging sensor for each wavelength range of the crop canopy. The images acquired by each imaging sensor were used to develop the models for predicting the Chinese cabbage yield. Methods: The models for predicting the Chinese cabbage (Brassica campestris L.) yield, with multispectral images based on unmanned aerial vehicle (UAV), were developed by simple linear regression (SLR) using vegetation indices, and forward stepwise multiple linear regression (MLR) using four spectral bands. The model with hyperspectral images based on the ground were developed using forward stepwise MLR from the significant spectral bands selected by dimension reduction methods based on a partial least squares regression (PLSR) model of high precision and accuracy. Results: The SLR model by the multispectral image cannot predict the yield well because of its low sensitivity in high fresh weight. Despite improved sensitivity in high fresh weight of the MLR model, its precision and accuracy was unsuitable for predicting the yield as its $R^2$ is 0.697, root-mean-square error (RMSE) is 1170 g/plant, relative error (RE) is 67.1%. When selecting the significant spectral bands for predicting the yield using hyperspectral images, the MLR model using four spectral bands show high precision and accuracy, with 0.891 for $R^2$, 616 g/plant for the RMSE, and 35.3% for the RE. Conclusions: Little difference was observed in the precision and accuracy of the PLSR model of 0.896 for $R^2$, 576.7 g/plant for the RMSE, and 33.1% for the RE, compared with the MLR model. If the multispectral imaging sensor composed of the significant spectral bands is produced, the crop yield of a wide area can be predicted using a UAV.

• Journal of Biomedical Engineering Research
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• v.38 no.1
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• pp.9-15
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• 2017

Recently, flexible cages have been introduced in an attempt to absorb and reduce the abnormal load transfer along the anterior parts of the spine. They are designed to be used with the pedicle screw systems to allow some mobility at the index level while containing ROM at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the flexible cage when combined with pedicle screws with flexible rods. The post-operated models were constructed by modifying the L4-5 of a previously-validated 3-D FE model of the intact lumbar spine (L2-S1): (1) Type 1, flexible cage only; (2) Type 2, pedicle screws with flexible rods; (3) Type 3, interbody fusion cage plus pedicle screws with rigid rods; (4) Type 4, interbody fusion cage plus Type 2; (5) Type 5, Type 1 plus Type 2. Flexion/extension of 10 Nm with a compressive follower load of 400N was applied. As compared to the Type 3 (62~65%) and Type 4 (59~62%), Type 5 (53~55%) was able to limit the motion at the operated level effectively, despite moderate reduction at the adjacent level. It was also able to shift the load back to the anterior portions of the spine thus relieving excessively high posterior load transfer and to reduce stress on the endplate by absorbing the load with its flexible shape design features. The likelihood of component failure of flexble cage remained less than 30% regardless of loading conditions when combined with pedicle screws with flexible rods. Our study demonstrated that flexible cages when combined with posterior dynamic system may help reduce subsidence of cage and degeneration process at the adjacent levels while effectively providing stability at the operated level.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.113-123
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• 2011

Recently, the global warming problem has arised around world, many nations has set up a various regulations for decreasing $CO_2$. In particular, $CO_2$ emissions reduction effect is very powerful in transport part, so there is a rising interest about development of green car, or electric vehicle in auto industry. For this reason, it is important to make a strategy for charging infra and forcast electric power demand, but it hasn't introduced about demand forecasting electric vehicle. Thus, this paper presents a demand forecasting for electric vehicles using choice based multigeneration diffusion model. In this paper, it estimates innovation coefficient, immitation coefficient in Bass model by using hybrid car market data and forecast electric vehicle market by year using potential demand market through SP(Stated Preference) experiment. Also, It facilitates more accurate demand forecasting electric vehicle market refelcting multigeneration diffusion model in accordance with attribute progress in development of electric vehicle. Through demand forecasting methodology in this paper, it can be utilized power supply and building a charging infra in the future.