• Journal of Photoscience
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• 제9권2호
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• pp.518-520
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• 2002

Photodynamic therapy (PDT) is a treatment modality based on photochemical reaction and the resultant cytotoxic reactive oxygen species. The platelet thrombus formation leading to stasis observed in vivo during PDT is called vascular shut down (VSD) effect. To investigate the mechanism of the VSD effect, we observed Human Umblical Vein Endothelial Cell (HUVEC) injury induced by photochemical reaction. We observed cell retraction and blebbing after PDT. It seems that the injury was not fetal and only morphological change. Then, the cytoplasm was stained by Calcein-AM and subendothelial area was evaluated from fluorescence microscopy. The rate of subendothelial area after PDT increased significantly. Second, we investigated interaction between neutrophils and HUVEC. Human promyelocytic leukemia cells (HL-60) were differentiated into neutrophil by incubation with all-trans retinoic acid. Calcein-AM labeled neutrophil adhesion to HUVEC was evaluated from fluorescence microscopy. PDT-induced neutrophil adhesion to HUVEC depended more on the exposure of subendothlial area than on neutrophil activation. This result suggests that there is a certain interaction between neutrophil and HUVEC during PDT.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.433-438
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• 2004

In this paper, we at first describe the linear age-dependent population system. In addition, we introduce the nonlinear population system. Using these age-dependent population systems, we evaluate the stability of these age-dependent population systems and determine the optimal birth rates that realize a target distribution which relaxes an aging population. In this paper, we focus on Japan's population and we use the amount of demographic statistics of Japan in year 2000.

• 시스템엔지니어링학술지
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• 제11권2호
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• pp.137-146
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• 2015

This paper addresses the definition of the driver's functions for an automated vehicle of level 3, as defined by the Society of Automotive Engineers. By combining the constituent systems surrounding the automated vehicles in specific use cases, their interactions could be refined in a stepwise approach. This approach enables traceability of interactions between drivers, automated driving systems, and other constituent systems.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.145.1-145.1
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• 2007

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2001년도 Bulletin of The 5th Asian Design Conference International Symposium on Design Science
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• pp.26.2-26
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• 2001

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2001년도 Bulletin of The 5th Asian Design Conference International Symposium on Design Science
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• pp.1.2-1
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• 2001

• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 추계 학술발표회 논문집
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• pp.49-53
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• 2005

• Asian Journal of Atmospheric Environment
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• 제12권1호
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• pp.78-86
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• 2018

Filter-based sampling techniques are the conventional way to collect particulate matter, but particles collected and entangled in the filter fibers are difficult to be removed and thus not suited for the following cell- and animal-based exposure experiments. Collecting aerosol particles in powder form using a cyclone instead of a filter would be a possible way to solve this problem. We developed a hybrid virtual-impactor/cyclone high-volume fine and coarse particle sampler and assessed its performance. The developed system achieved 50% collection efficiency with components having the following aerodynamic cut-off diameters: virtual impactor, $2.4{\mu}m$; fine-particle cyclone, $0.18-0.30{\mu}m$; and coarse-particle cyclone, $0.7{\mu}m$. The virtual impactor used in our set-up had good $PM_{2.5}$ separation performance, comparable to that reported for a conventional real impactor. The newly developed sampler can collect fine and coarse particles simultaneously, in combination with exposure testing with collected fine- and coarse-particulate matter samples, should help researchers to elucidate the mechanism by which airborne particles result in adverse health effect in detail.

• Earthquakes and Structures
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• 제8권4호
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• pp.889-913
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• 2015

Structural vibration characteristics of a semi-active base-isolated building were investigated using seismic observation records including those of the 2011 Great East Japan earthquake (Tohoku earthquake). Three different types of analyses were conducted. First, we investigated the long-term changes in the natural frequencies and damping factors by using an ARX model and confirmed that the natural frequency of the superstructure decreased slightly after the main shock of the Tohoku earthquake. Second, we investigated short-term changes in the natural frequencies and damping factors during the main shock by using the N4SID method and observed different transition characteristics between the first and second modes. In the second mode, in which the superstructure response is most significant, the natural frequency changed depending on the response amplitude. In addition, at the beginning of the ground motion, the identified first natural frequency was high possibly as a result of sliding friction. Third, we compared the natural frequencies and damping factors between the conditions of a properly functional semi-active control system and a nonfunctional system, by using the records of the aftershocks of the Tohoku earthquake. However, we could not detect major differences because the response was probably influenced by sliding friction, which had a more significant effect on damping characteristics than did the semi-active dampers.

• Asian Journal of Atmospheric Environment
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• 제9권2호
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• pp.137-145
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• 2015

This study focused on the measurement of the actual charging state of ambient aerosol particles, which is important for understanding the intricate process of adverse health effects caused by particulate matter (PM). The net electrostatic charging state of $PM_{2.5}$ collected on filter media was measured in this study. The Faraday cage method and surface potential measurements were used in this study. The results showed that the polarities of the net charging state measured using these two methods were in agreement for 42 out of 48 samples (87.5%), and 36 samples (75%) were negatively charged. The filters were not significantly charged by friction between the filters and air not containing PM. Charge addition to or leakage from the filters was not observed over a two-month storage period. Net charging state of $PM_{2.5}$ collected on the filters was concluded to be negative in most cases, based on data's support of the assumption that aerosol charging state is not altered by the process of PM collection using filter.