• 한국전기전자재료학회논문지
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• 제37권1호
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• pp.79-87
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• 2024

This paper is a study on the optimal microdroplet generation conditions in indirect charging electrostatic spraying. Unlike the direct charging method, which applies power to the nozzle, the indirect charging method applies power to the discharge electrode between the nozzle and the collection electrode. Therefore, an electrically simplified system can be obtained by minimizing the insulation part a stable spray pattern can be obtained with a wide spray angle, and a stable spray pattern can be obtained with a wide spray angle. To conduct the study, an indirect charging type electrostatic spray visualization system was constructed and the static characteristics of the microdroplets were analyzed through image processing of the spray shape of the microdroplets. The total number of microdroplets and the number of microdroplets per power consumption are confirmed according to the changes in the distance between the discharge electrode and the collection electrode, the flow rate, and the applied voltage, which affect the generation of microdroplets, and using this, the optimal generation conditions are derived and the corresponding microdroplet size distribution was analyzed. As a result of the experiment, it was confirmed that the optimal generation condition was at a flow rate of 15 to 20 mL/min and a voltage of -22.5 to -25 kV in terms of the number of microdroplets, and at a flow rate of 15 to 20 mL/min and a voltage of -20 kV in terms of energy consumption efficiency.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.40-40
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• 2023

Atopic dermatitis is a chronic inflammatory skin diseases caused by skin barrier dysfunction. Allium victoralis var. Platyphyllum (AVP) is a perennial plant used as vegetable and herbal medicine. The purpose of this study was to suggest that AVP is a new cosmetic material by examining the effects of AVP on the skin barrier and inflammatory response. A bibliometric network analysis was performed through keyword co-occurrence analysis by extracting author keyword from 69 articles retrieved from SCOPUS. We noted the anti-inflammatory activity shown by the results of clustering and mapping from network visualization analysis using VOSviewer software tool. HPLC-UV analysis showed that AVP contains 0.12 ± 0.02 mg/g of chlorogenic acid and 0.10 ± 0.01 mg/g of gallic acid. AVP at 100 ㎍/mL was shown to increase the mRNA levels of filaggrin and involucrin related to skin barrier function by 1.50-fold and 1.43-fold, respectively. In the scratch assay, AVP at concentrations of 100 ㎍/mL and 200 ㎍/mL significantly increased the cell migration rate and narrowed the scratch area. In addition, AVP suppressed the increase of inflammation-related factors COX-2 and NO and decreased the release of β-hexosaminidase. This study suggests that AVP can be developed as a functional cosmetic material for atopy management through skin barrier protection effects, anti-inflammatory and anti-itch effects.

• Applied Microscopy
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• 제45권4호
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• pp.225-229
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• 2015

Transition metal dichalcogenides (TMDs) are a class of two-dimensional (2D) materials that have attracted growing interest because of their promising applications. The properties of TMDs strongly depend on the crystalline structure and the number and stacking sequence of layers in their crystals and thin films. Though electrical, mechanical, and magnetic studies of 2D materials are being conducted, there is an evident lack of direct atom-by-atom visualization, limiting insight on these highly exciting material systems. Herein, we present our recent studies on the characterization of 2D layered materials by means of aberration corrected scanning transmission electron microscopy (STEM), in particular via high angle annular dark field (HAADF) imaging. We have identified the atomic arrangements and defects in 2H stacked TMDs, 1T stacked TMDs, distorted 1T stacked TMDs, and vertically integrated heterojunctions of 2D TMDs crystals.

• 인터넷정보학회논문지
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• 제21권3호
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• pp.41-51
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• 2020

EDISON is a web-based platform that provides easy and convenient use of simulation software on high-performance computers. One of the most important roles of a computational science platform, such as EDISON, is to post-process and represent the simulation results data so that the user can easily understand the data. We interviewed EDISON users and collected requirements for post-processing and represent of simulation results, which included i) flexible data representation, ii) supporting various data representation components, and iii) flexible and easy development of view template. In previous studies, it was difficult to develop or contribute data representation components, and the view templates were not able to be shared or recycled. This causes a problem that makes it difficult to create ecosystems for the representation tool development of numerous simulation software. EDISON-VIEW is a framework for post-processing and representing simulation results produced from the EDISON platform. This paper proposes various methods used in the design and development of the EDISON-VIEW framework to solve the above requirements and problems. We have verified its usefulness by applying it to simulation software in various fields such as material, computational fluid dynamics, computational structural dynamics, and computational chemistry.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1115-1119
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• 2005

The paper proposes the elastic modulus evaluation technique of a cantilever beam by vibration analysis based on time-average electronic speckle pattern interferometry (TA-ESPI) with non-contact and nondestructive and Euler-Bernoulli equation. General approaches for the measurement of elastic modulus of thin film are Nano indentation test, Bulge test and Micro-tensile test and so on. They each have strength and weakness in the preparation of test specimen and the analysis of experimental result. ESPI has been developed as a common measurement method for vibration mode visualization and surface displacement. Whole-field vibration mode shape (surface displacement distribution) at a resonance frequency can be visualized by ESPI. And the maximum surface displacement distribution from ESPI is a clue to find the resonance frequency at each vibration mode shape. And the elastic modules of test material can be easily estimated from the measured resonance frequency and Euler-Bernoulli equation. The TA-ESPI vibration analysis technique is able to give the elastic modulus of materials through the simple processing of preparation and analysis.

• 한국콘텐츠학회논문지
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• 제11권7호
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• pp.30-37
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• 2011

본 연구는 3D 뷰 콘텐츠 개발을 위한 3D 콘텐츠 기반 작업 프로세스 시뮬레이션을 개발하였다. 이를 위하여 3D 뷰 기술에 대한 표현기법을 기술하였고, 자동차 및 PC 조립 공정을 가상시나리오에 따라 작업자를 도와주는 기술을 3D 뷰를 통하여 보여준다. 또한 3D 정보가시화를 위하여 3D MAX를 이용한 콘텐츠 모델링하는 기능들인 좌표설정, 모델링에 재질 입히기, 랜더링, 그리고 3D object 파일을 이용한 Max Script로 Customizing하여 3D 모델링하는 과정을 개발하였다.

• 한국콘텐츠학회논문지
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• 제11권7호
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• pp.497-507
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• 2011

본 논문은 건축자재들을 컴포넌트와 패턴으로 조립하여 패턴 단위로 건축설계가 효율적으로 이루어질 수 있도록 하는 스틸하우스 설계 인터페이스를 개발한다. 또한 이 기술을 이용하여 건축의 공정에 설계, 분석, 변경정보, 조립 등의 건축설계를 시뮬레이션을 통하여 건축의 손쉬운 변경과 비용을 효과적으로 절감하기 위한 기술을 지원하는 조립 건축설계 시스템 개발을 목적으로 한다. 특히 설계자와 사용자도 패턴을 이용하여 쉽게 건축물을 변경시킬 수 있으며 변경에 따라 필요한 자재들의 패턴 정보와 변경된 건축물의 설계도가 자동 생성된다. 또한 개인의 숙련도나 지식 가시화를 통해 발생할 수 있는 지식검색 역시 구현 목표로 한다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.460-467
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• 2011

중속 디젤 엔진에 적용된 연료 펌프의 스필 포트 및 플런저 벽면에서 발생하는 캐비테이션 손상 원인을 규명하기 위해, 연료 펌프의 스필 포트 내부에서 일어나는 캐비테이션 유동 현상에 대한 가시화를 수행 하였다. 이를 위해 기존 연료 펌프를 개조하여 사파이어 가시창을 제작, 설치하고, 고속 카메라와 Nd-YAG 레이져 및 산업용 내시경을 이용한 다양한 가시화 방법을 모색하였다. 취득한 영상의 분석 결과 연료의 분사 과정 동안 네 가지 형태의 특징적인 캐비테이션 현상이 목격되며, 특히 연료 압송 과정의 종료 직전과 직후 에서 발생하는 분수 형태와 제트 형태의 캐비테이션이 손상의 지배적인 원인으로 판명되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 학술대회 논문집 전문대학교육위원
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• pp.183-186
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• 2007

Realistic deformation of computer simulated anatomical structures is computationally intensive. As a result, simple methodologies not based in continuum mechanics have been employed for achieving real time deformation of virtual reality. Since the graphical interpolations and simple spring models commonly used in these simulations are not based on the biomechanical properties of tissue structures, these "quick and dirty"methods typically do not accurately represent the complex deformations and force-feedback interactions that can take place during surgery. Finite Element(FE) analysis is widely regarded as the most appropriate alternative to these methods. However, because of the highly computational nature of the FE method, its direct application to real time force feedback and visualization of tissue deformation has not been practical for most simulations. If the mathematics are optimized through pre-processing to yield only the information essential to the simulation task run-time computation requirements can be drastically reduced. To apply the FEM, We examined a various in verse matrix method and a deformed material model is produced and then the graphic deformation with this model is able to force. As our simulation program is reduced by the real-time calculation and simplification because the purpose of this system is to transact in the real time.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.253-256
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• 1995

Polymers have been one of the emerging biomedical materials in the area of biomedical research which are applicable to the human body. For human applications, noninvasive characterization of the biomedical polymers has been one of the important topics, and is valuable information. Among others, the swelling rate is one of the important measurements needed for the hydrophilic polymers. NMR imaging has been a suitable method for the noninvasive study of such a material since it is sensitive to many physical and biochemical changes of the specimens. In addition, NMR techniques possess many useful intrinsic properties such as the relaxation and diffusion effects. The present study has provided a noble and noninvasive method of measuring the process of swelling as well as volumetric changes occurred in polymers and drug delivery processes in a drug delivery system (DDS) together with changes of released drug. This gives information, relating with both water ingress process, volumetric changes of polymer specimens and the visualization of sequential drug delivery process. Also, this study provides more reliable method to ascertain the time dependent swelling process compared to the conventional method. The important aspects is that the proposed method is truly noninvasive and is able to ascertain time dependent processes.