• Journal of the Korean Chemical Society
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• v.28 no.4
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• pp.217-230
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• 1984

The MINDO/3 method was used in determination of transition states and activation barriers for various 1,2-, 1,3- and 1,5-sigmatropic hydrogen rearrangements involving systems with central carbon atom. It was found that, besides the consideration of orbital symmetry, steric effect, aromaticity, and orbital interactions were found to dictate the stability of the transition state. For systems with hetero atoms, lone pair orbitals tend to ease orbital distortion required at the transition state by participating in hydrogen transfer process and were found to lower the activation barrier accordingly. Comparison of the relative barrier heights with those obtained by using more sophisticated ab initio MO calculations showed that the MINDO/3 results give qualitatively the same tendency of the relative order of the activation barriers.

• Journal of IKEEE
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• v.24 no.1
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• pp.154-160
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• 2020

This paper presents a grid current control algorithm for a grid connected inverter (GCI) system in a stationary reference frame. When a Proportional Integral (PI) controller at a stationary reference frame is used in a GCI system, steady state error and phase lags are presented because AC signals are controlled at a stationary reference frame. In this paper, a feedforward controller is applied to the PI controller to compensate the steady state error and phase lags by improving command tracking performance. In addition, disturbance rejection control is applied to the PI controller to protect the GCI system by eliminating disturbance, grid voltage in a GCI system, when a grid fault such as line-to-line fault, happens. The proposed GCI current control algorithm is analyzed in a frequency domain and a simulation model of the proposed GCI current control system is developed for verification of the performance.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.101-106
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• 2018

We examined refractive error, the corrected visual acuity, phoria and fusional reserve of 114 healthy myopes and hyperopia who had no strabismus, no ocular and physical diseases. We evaluated the occurrence of asthenopia according to phoria and fusional reserve. 41 out of 114 subjects which exophoria was 69% and esophoria was 5.5%, orthophoria was 26% made a complaint against asthenopia. The subjects who had exophoria of $0-6{\Delta}$ in the range of normal state was 61.4%, while the subjects who had exophoria of $7{\Delta}$ or more in the range of abnormal state was 38.6%. Reducing fusional reserve was associated with increasing phoria. The fusional reserve twice or more than phoria were 27.2%, and twice or under were 72.8%. Futhermore, AC/A ratio for heterophoria was found from 1.0 to 12.6 and its relationship to asthenopia of phoria could not be determined.

• Journal of IKEEE
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• v.24 no.3
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• pp.877-882
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• 2020

This paper presents performance comparison study of current control methods for grid connected inverter (GCI) system. Different current control methods have been developed for GCI systems and each controller has its own advantages and limitations. Steady state and transient dynamic performance of the GCI current controllers are compared in this paper. The performance of the proposed command feedforward control (CFFC) and disturbance rejection control (DRC) is analyzed before and after application to all GCI current controllers. The proposed CFFC and DRC control algorithms is analyzed in a frequency domain and the simulation and experiment models of each GCI current control methods are developed for verification of the performance.

• Journal of Korean society of Dental Hygiene
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• v.17 no.4
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• pp.555-564
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• 2017

Objectives: The purpose of the study is to investigate the oral health assessment and satisfaction according to recognition and beneficiary oral health projects for oral health promotion of the elderly. Methods: The subjects were elderly over 65 years old in Jeonbuk province. The study instrument was structured questionnaire including general characteristics, oral care condition, recognition of project, satisfaction of project, geriatric oral health assessment index, life satisfaction. For data analysis, the study used independent t-test, one way ANOVA and Pearson correlation analysis. Results: The subjects of this study were well aware of the perceived health status of oral health projects. Satisfaction scaling project was the highest in the satisfaction of the received projects. People who recognized the oral health project had a high oral health assessment index. People who benefit from oral health project showed higher satisfaction in life. Conclusions: As for the elderly's perception on oral health care, they showed higher oral health assessment index and life satisfaction.

• Journal of Korea Multimedia Society
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• v.25 no.5
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• pp.730-738
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• 2022

Based on visual Thinking theory, VR(virtual reality) game changes the traditional form of memory and maps the content into game elements to realize the immersive spatial memory mode. This paper analyzes the influencing factors of game design and system function construction. This paper proposes a hypothesis: with the help of visual thinking theory, VR game is helpful to improve learners' visual memory, and carries out research. The experiment sets different levels of game through empirical research and case analysis of memory flip game. For example, when judging two random cards. If the pictures are the same, it will be judged as the correct combination; if they are different, the two cards will be restored to the original state. The results are analyzed by descriptive statistical analysis and AMOS data analysis. The results show that game content using the concept of "Memory Palace", which can improve the accuracy of memory. We conclude that the use of spatial localization characteristics in flip games combining visual thinking can improve users' memory by helping users memorize and organize information in a Virtual environment, which means VR games have strong feasibility and effectiveness in improving memory.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.2
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• pp.135-144
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• 2022

An antidiabetic drug, rosiglitazone is a member of the drug class of thiazolidinedione. Although restrictions on use due to the possibility of heart toxicity have been removed, it is still a drug that is concerned about side effects on the heart. We here examined, using Chinese hamster ovary cells, the action of rosiglitazone on Kv1.5 channels, which is a major determinant of the duration of cardiac action potential. Rosiglitazone rapidly and reversibly inhibited Kv1.5 currents in a concentrationdependent manner (IC₅₀ = 18.9 μM) and accelerated the decay of Kv1.5 currents without modifying the activation kinetics. In addition, the deactivation of Kv1.5 current, assayed with tail current, was slowed by the drug. All of the results as well as the usedependence of the rosiglitazone-mediated blockade indicate that rosiglitazone acts on Kv1.5 channels as an open channel blocker. This study suggests that the cardiac side effects of rosiglitazone might be mediated in part by suppression of Kv1.5 channels, and therefore, raises a concern of using the drug for diabetic therapeutics.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.655-658
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• 2021

The purpose of multimodal medical image fusion (MMIF) is to integrate images of different modes with different details into a result image with rich information, which is convenient for doctors to accurately diagnose and treat the diseased tissues of patients. Encouraged by this purpose, this paper proposes a novel method based on a two-scale decomposer and detail preservation model. The first step is to use the two-scale decomposer to decompose the source image into the energy layers and structure layers, which have the characteristic of detail preservation. And then, structure tensor operator and max-abs are combined to fuse the structure layers. The detail preservation model is proposed for the fusion of the energy layers, which greatly improves the image performance. The fused image is achieved by summing up the two fused sub-images obtained by the above fusion rules. Experiments demonstrate that the proposed method has superior performance compared with the state-of-the-art fusion methods.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.656-658
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• 2022

The purpose of infrared and visible image fusion is to integrate images of different modes with different details into a result image with rich information, which is convenient for high-level computer vision task. Considering many deep networks only work in a single scale, this paper proposes a novel image fusion based on three-scale dense network to preserve the content and key target features from the input images in the fused image. It comprises an encoder, a three-scale block, a fused strategy and a decoder, which can capture incredibly rich background details and prominent target details. The encoder is used to extract three-scale dense features from the source images for the initial image fusion. Then, a fusion strategy called l₁-norm to fuse features of different scales. Finally, the fused image is reconstructed by decoding network. Compared with the existing methods, the proposed method can achieve state-of-the-art fusion performance in subjective observation.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.53-57
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• 2009

Purpose: To study the relationship of N.P.C, heterophoria and near convergence and divergence by amount of the refractive error. Methods: All subjects have no ocular disease and their mean age is 22.7. All 39 subjects examined about refractive error, near point of convergence (NPC), heterophoria, near convergence and divergence. Results: Classified by low refractive state, middle refractive state, and high refractive state compared with the expected value of Morgan. NPC had been measured within low and middle refractive state eight all the 8cm. However, high refractive state measured 9.64 cm. Low and middle refractive state for the classification by near phoria. Near esophoria groups was smallest by near divergence and exophoria groups was smallest by near convergence. Conclusions: Near convergence were largest with esophoria while near divergence were largest with exophoria.