• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 춘계학술대회
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• pp.136-138
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• 1994

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.105.2-105.2
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• 2016

For the rational design and facile fabrication of novel nanostructures, we present a new approach to generating arrays of three-dimensionally tunable nanostructures by exploiting light-matter interaction. To create controlled three-dimensional (3D) nanostructures, we utilize the 3D spatial distribution of light, induced by the light-matter interaction, within the matter to be patterned. As a systematic approach, we establish 3D modeling that integrates the physical and chemical effects of the photolithographic process. Based on a comprehensive analysis of structural formation process and nanoscale features through this modeling, we are able to realize three-dimensionally tunable nanostructures using facile photolithographic process. Here we first demonstrate the arrays of three-dimensionally controlled, stacked nanostructures with nanoscale, tunable layers. We expect that the promising strategy would open new opportunities to produce the arrays of tunable 3D nanostructures using more accessible and facile fabrication process for various biomedical applications ranging from biosensors to drug delivery devices.

• 대한의용생체공학회:의공학회지
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• 제27권2호
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• pp.64-72
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• 2006

The present study introduces a new cortical patch-based source model for EEG/MEG cortical source imaging to consider anatomical constraints more precisely. Conventional source models for EEG/MEG cortical source imaging have used coarse cortical surface mesh or sampled small number of vertices from fine surface mesh, and thus they failed to utilize full anatomical information which nowadays we can get with sub-millimeter modeling accuracy. Conventional ones placed a single dipolar source on each cortical patch and estimated its intensity by means of various inverse algorithms; whereas the suggested cortical patch-based model integrates whole cortical area to construct lead field matrix and estimates current density that is assumed to be constant in each cortical patch. We applied the proposed and conventional models to realistic EEG data and compared the results quantitatively. The quantitative comparisons showed that the proposed model can provide more precise spatial descriptions of neuronal source distribution.

• Molecules and Cells
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• 제45권2호
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• pp.53-64
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• 2022

Three-dimensional cultures of human neural tissue/organlike structures in vitro can be achieved by mimicking the developmental processes occurring in vivo. Rapid progress in the field of neural organoids has fueled the hope (and hype) for improved understanding of brain development and functions, modeling of neural diseases, discovery of new drugs, and supply of surrogate sources of transplantation. In this short review, we summarize the state-of-the-art applications of this fascinating tool in various research fields and discuss the reality of the technique hoping that the current limitations will soon be overcome by the efforts of ingenious researchers.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.700-704
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• 2015

As pH is a widely used index in chemical, medical, and environmental applications, research on pH sensors has been active in recent years. This study obtained RGB values by measuring the reflected light from a liquid sample to detect fine changes in pH, and performed mathematical modeling to investigate the relationship between the detected optical signal and pH value. Also, the trends in pH changes were easily identified by analyzing RGB values and displaying them in the color coordinate for easy visualization of data. This method implemented a user-friendly system that can measure and analyze in real time. This system can be used in many fields such as genetic engineering, environmental engineering, and clinical engineering, because it not only can measure pH but also replaces a colorimeter or turbidimeter.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.402-408
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• 2006

The choice of suitable hip implant is one of important factors in the total hip arthroplasty (THA). In clinical view point, an improper adaptation of hip implant might induce abnormal stress distribution to the bone, which can shorten the lifespan of replaced hip implant. Currently, interest in the custom-designed hip implants has increased as studies reveal the significance of geometric shape of patient's femur in modeling and designing the implants. In this study, we have developed custom-designed hip implant models with various sizes, and analyzed the stress distribution in the bone and bone cement using the Finite Element Method. It was found that minimizing the gap between implant stem and femoral cavity is crucial to minimize the stress concentration in the bone.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.64-65
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• 1998

The aim of this work is to develop computerized 2-D radiation therapy planning system. The algorithms to compute dose for photon, electron, radioisotope have been developed, and dose distributions were superimposed on CT or MR images. Using object oriented modeling the structure of program has been designed for the efficient user-interface. Finally, a prototyp of 2-D radiation therapy planning system has been successfully applied in clinical cases for the demonstration.

• 순환기질환의공학회:학술대회논문집
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• 순환기질환의공학회 2006년도 제6회 학술대회
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• pp.24-26
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• 2006

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.82-83
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• 1996

In this paper, we present a simplified model for complicance determination of the moving-actuator type totally implantable artificial heart (TAH). The modeling equations are derived from the mechanics and geometry of the TAH components. The interventricular pressure and volume are computed for determining the compliance of the interventricular space using this model. The model is capable of generating realistic hemodynamic variables such as the left atrial pressure and interventricular pressure and is proved to be acceptable. This model can be used as an initial step for analyzing characteristics of the moving-actuator type TAH.

• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.182-202
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• 2022

PURPOSE. The aim of this study is to summarize various biomechanical aspects in evaluating the long-term stability of dental implants based on finite element method (FEM). MATERIALS AND METHODS. A comprehensive search was performed among published studies over the last 20 years in three databases; PubMed, Scopus, and Google Scholar. The studies are arranged in a comparative table based on their publication date. Also, the variety of modeling is shown in the form of graphs and tables. Various aspects of the studies conducted were discussed here. RESULTS. By reviewing the titles and abstracts, 9 main categories were extracted and discussed as follows: implant materials, the focus of the study on bone or implant as well as the interface area, type of loading, element shape, parts of the model, boundary conditions, failure criteria, statistical analysis, and experimental tests performed to validate the results. It was found that most of the studied articles contain a model of the jaw bone (cortical and cancellous bone). The material properties were generally derived from the literature. Approximately 43% of the studies attempted to examine the implant and surrounding bone simultaneously. Almost 42% of the studies performed experimental tests to validate the modeling. CONCLUSION. Based on the results of the studies reviewed, there is no "optimal" design guideline, but more reliable design of implant is possible. This review study can be a starting point for more detailed investigations of dental implant longevity.