• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1156-1158
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• 2010

경주용 카트에 현가장치와 차동장치가 존재하지 않으므로 선회 시에 후륜 내측 바퀴가 들리도록 애커먼 조향 기구와 큰 킹핀 경사각, 캐스터으로 설계되어 있다. 경주용 카트 드라이버는 고속으로 주행하고 빠르게 선회 시가 가능하도록 충분한 기능을 보유하도록 공학적인 해석이 필요하다. 이 논문에서는 조향기구의 설계 시 가장 중요인자인 애커먼 조향 기구를 평면에서 다양한 인자에 대하여 해석하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.328-330
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• 2004

유전자 발현은 다양한 전사 인자들의 상호 작용에 의해서 조절되어진다 이러한 전사 인자들에 존재하는 모티프는 직접적으로 조절 작용을 위한 기능을 수행한다. 또한 대부분의 경우에서 여러 모티프가 함께 유전자 발현 기작을 위하여 조절 작용을 한다. 따라서 이러한 모티프들이 어떤 조합으로 함께 전사 과정에 관여하는지 여부를 밝히는 작업은 중요한 일이다. 본 논문에서 진화 연산을 응용하여, 다양한 조건 하에 전사 과정에 중요하게 작용하는 모티프들의 조합을 알아보았고, 그 결과를 기본적인 k-Means 알고리즘 등과 비교하여 제안한 방법이 유전자들의 상관관계에 있어서 보다 우수한 결과를 보임을 알 수 있었다.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.1-15
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• 2016

The study of ecosystem service assessment has been actively researched and developed from Millennium Ecosystem Assessment(MA) and The Economics of Ecosystems and Biodiversity(TEEB). However, current assessments are limited to monetary assessments of ecosystem function and do not account for the effects of environmental factors and socioeconomic status. This study proposes methods to evaluate ecosystem service based on environmental and socioeconomic factors. The study assesses water yield function through the water yield model in InVEST Tool, and evaluates the overall ecosystem service of water yield as reflected by the amount of precipitation and population of the area. Results show that a difference exists between spatial distributions of the ecosystem function of water yield derived from natural conditions such as land cover and soil, and the spatial distribution of the ecosystem service that accounts for climate and socioeconomic factors. The value of ecosystem service increases for an area of higher population and lower precipitation with similar water yield. Thus, the ecosystem service of water yield should be evaluated not only by the water yield function, but also by climate and socioeconomic factors. The evaluation process described for this study should also be applicable to the evaluation of ecological services in other sectors.

• Food Science and Industry
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• v.53 no.4
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• pp.390-396
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• 2020

We investigated the anti-obesity effect of Gelidium elegans extract (GE) on 3T3-L1 preadipocytes and a high-fat-diet (HFD)-induced mouse model. The results of the present study demonstrated that GE prevents weight gain induced by a high-fat diet (HFD) by modulating the adenosine monophosphate-activated protein kinase (AMPK)-PR domain-containing 16 (PRDM16)-uncoupling protein-1 (UCP-1) pathway in a mice model. Moreover, in vitro results show that GE suppressed adipocyte differentiation by modulating adipogenic regulators, stimulated lipolysis by activating ATGL, and inhibited adipogenesis by downregulating various enzymes associated with triglyceride synthesis. GE was also found to upregulate AMPK phosphorylation as well as the expression of UCP1 and PRDM16 proteins, leading to measurable changes in the beige-like phenotype differentiation of 3T3-L1 cells. Taken together, these findings suggest the role of GE as a functional food ingredient extracted from Gelidium elegans to increase energy expenditure and anti-obesity efficacy.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.05a
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• pp.96-96
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• 2003

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.450-457
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• 2001

This study aimed to clarify the influencing site factors of the mesopore ratio on a pore geometry of surface soil in deciduous stands as an index of the water retention capacity. Fifteen factors including site conditions and soil properties were analyzed by spss/pc+ for the data collected during March to October of 1994. The factors influencing the mesopore ratio(pF2.7) on the surface soil were as follows; tree height, under vegetation coverage and organic matter contents of soil. And influencing factor on the ratio of mesopore in the soil surface was correlated with surface soil hardness shows high negative significance. Also, multiple regression equations for mesopore ratios of surface soil hardness, organic matter contents of soils show high significance($R^2=0.84$). In deciduous stands, it is effective in promoting development on the ratio of mesopore that forest practice for enhancing of the water resource retention capacity should be carried out when the under vegetation coverage rates of stands are maintained from 30 to 80 percentages.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04b
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• pp.615-618
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• 2001

본 논문에서는 네트워크 계층 및 어플리케이션 계층의 트래픽 분석을 수행할 수 있는 RMON2 MIB를 이용하여 LAN 세크먼트의 트래픽을 분석하는 웹 기반 RMON 에이전트 시스템을 설계하고 구현하고자 한다. 구현된 RMON 에이전트 시스템은 제어기능 설정 모듈과 패킷 수집 모듈 그리고 패킷 분석 모듈로 구성된다. 제어기능 설정 모듈은 관리자가 RMON 에이전트가 수행할 제어기능과 제어 인자들을 설정하는 기능을 수행한다. 패킷 수집 모듈은 네트워크상의 패킷을 수집하고 패킷 분석 모듈은 설정된 제어 기능에 따라 수집된 패킷으로부터 필요한 정보를 얻어 RMON MIB 에 따라 설계된 데이터베이스에 저장한다. 본 RMON 에이전트 시스템은 웹 인터페이스를 사용하여 관리자가 인터넷을 통해 제어기능 설정 및 모니터링할 수 있게 함으로써 대규모 네트워크에서 많은 RMON 에이전트 시스템들의 관리를 용이하게 할 수 있으며, PC 상에서 순수한 소프트웨어만으로 구현되었으므로 고가의 RMON 장비 없이 효율적인 네트워크 관리를 수행할 수 있다.

• Progress in Medical Physics
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• v.21 no.2
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• pp.153-164
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• 2010

To determine the clinical target volumes considering vascularity and cellularity of tumors, the software was developed for mapping of the analyzed biological clinical target volumes on anatomical images using regional cerebral blood volume (rCBV) maps and apparent diffusion coefficient (ADC) maps. The program provides the functions for integrated registrations using mutual information, affine transform and non-rigid registration. The registration accuracy is evaluated by the calculation of the overlapped ratio of segmented bone regions and average distance difference of contours between reference and registered images. The performance of the developed software was tested using multimodal images of a patient who has the residual tumor of high grade gliomas. Registration accuracy of about 74% and average 2.3 mm distance difference were calculated by the evaluation method of bone segmentation and contour extraction. The registration accuracy can be improved as higher as 4% by the manual adjustment functions. Advanced MR images are analyzed using color maps for rCBV maps and quantitative calculation based on region of interest (ROI) for ADC maps. Then, multi-parameters on the same voxels are plotted on plane and constitute the multi-functional parametric maps of which x and y axis representing rCBV and ADC values. According to the distributions of functional parameters, tumor regions showing the higher vascularity and cellularity are categorized according to the criteria corresponding malignant gliomas. Determined volumes reflecting pathological and physiological characteristics of tumors are marked on anatomical images. By applying the multi-functional images, errors arising from using one type of image would be reduced and local regions representing higher probability as tumor cells would be determined for radiation treatment plan. Biological tumor characteristics can be expressed using image registration and multi-functional parametric maps in the developed software. The software can be considered to delineate clinical target volumes using advanced MR images with anatomical images.

• Journal of Life Science
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• v.26 no.1
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• pp.129-139
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• 2016

Exercise increases the expression and interaction of major neurotrophic factors such as brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF) at both central and peripheral tissues, which contributes to improved brain and neural plasticity and cognitive function. Previous findings have been to understand the effect of light or moderate intensity aerobic exercise on neurotrophic factors and cognitive function, not that of high intensity aerobic exercise. However, recent findings suggest that high intensity interval training is a safe, less time-consuming, efficient way to improve cardiorespiratory fitness and weight control, thus American College of Sport Medicine (ACSM)’s guidelines for exercise prescription for various adult populations also recommend the application of high intensity interval training to promote their overall health. High intensity interval training also enhances the expression of BDNF, IGF-1, and VEGF at the brain and peripheral tissues, which improves cognitive function. Increased frequency of intermittent hypoxia and increased usage of lactate as a supplementary metabolic resource at the brain and neural components are considered a putative physiological mechanism by which high intensity interval training improves neurotrophic factors and cognitive function. Therefore, future studies are required to understand how increased hypoxia and lactate usage leads to the improvement of neurotrophic factors and what the related biological mechanisms are. In addition, by comparing with the iso-caloric moderate continuous exercise, the superiority of high intensity interval training on the expression of neurotrophic factors and cognitive function should be demonstrated by associated future studies.

• Journal of Life Science
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• v.34 no.7
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• pp.520-530
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• 2024

Tumor suppressor genes (TSGs) play a crucial role in maintaining cellular homeostasis. When the function of these genes is lost, it can lead to cellular plasticity that drives the development of various cancers, including small-cell lung cancer (SCLC), which is known for its aggressive nature. SCLC is primarily driven by numerous loss-of-function mutations in TSGs, often involving genes that encode epigenetic regulators. These mutations pose a significant therapeutic challenge as they are not directly targetable. However, understanding the molecular changes resulting from these mutations might provide insights for developing tumor intervention strategies. We propose that despite the heterogeneous genomic landscape of SCLC, the effects of mutations in patient tumors converge on a few critical pathways that drive malignancy. Specifically, alterations in epigenetic regulators lead to transcriptional dysregulation, pushing mutant cells toward a highly plastic state that makes them immune evasive and highly metastatic. This review will highlight studies showing how an imbalance of epigenetic regulators with opposing functions leads to the loss of immune recognition markers, effectively hiding tumor cells from the immune system. Additionally, we will discuss the role of epigenetic regulators in maintaining neuroendocrine features and how aberrant transcriptional control promotes epithelial-to-mesenchymal transition during tumor development. Although these pathways seem distinct, we emphasize that they often share common molecular drivers and mediators. Understanding the connection among frequently altered epigenetic regulators will provide valuable insights into the molecular mechanisms underlying SCLC development, potentially revealing preventive and therapeutic vulnerabilities for SCLC and other cancers with similar mutations.