• 대한기계학회논문집A
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• 제33권2호
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• pp.169-178
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• 2009

The presence of low adhesion at the wheel-rail contact point can result in skid of train wheels, and the skid, in turn, results in flats appearing on the wheels. Thus, anti-skid control has a crucial role for safe braking and prevention from flats that could cause a disastrous train accident. This paper presents dynamic modeling of a tilting train and the brake system of the tilting train, and analyzes the anti-skid logic used in the tilting train. The validity of the analysis is demonstrated via simulation study using Simulink for skid and re-adhesion circumstances of the tilting train.

• Food Science and Biotechnology
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• 제16권5호
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• pp.796-801
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• 2007

This study was conducted to investigate antioxidant activity and anti-immunological inflammatory effect of Allium victorialis subsp. platyphyllum extracts (AVPEs). Antioxidant activities of AVPEs were determined by free radical scavenging assay and reducing power test. Leaf-part extract had comparatively better antioxidant activity than other-part extracts. Antioxidant activity of extracts had protective effect for human umbilical vein endothelial cells (HUVECs) against superoxide anions secreted from activated neutrophils. Also, we observed AVPEs had inhibitory effects on the adherence of monocytic THP-1 to HUVEC monolayer to the basal level. Inhibitory effect on cell adhesion was caused by suppression of tumor necrosis factor-${\alpha}\;(TNF-{\alpha})-upregulated$ expression of vascular cellular adhesion molecule-1 (VCAM-1) and E-selectin in HUVECs. From these results, we expect to support the evidence of anti-immunological inflammatory effects of Allium victorialis subsp. platyphyllum (AVP) as a Korean traditional pharmaceutical.

• 한국융합학회논문지
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• 제11권10호
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• pp.363-368
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• 2020

배경; 수술 중, 후에 안과적 문제가 발생하는 경우는 매우 드물다. 이 연구는 견관절 수술 후 눈에 이상이 발견된 환자를 확인하고 그의 원인을 후향적으로 조사하였다. 방법; 2018년 1월에서 2019년 3월까지 본원에서 견관절경 수술을 받은 환자를 대상으로 후향적 연구방법을 통해 환자의 의무기록, 사용 약물들을 확인하였다. 로지스틱회귀분석을 통해 눈의 이상과 관련될 수 있는 여러 인자들을 가지고 연관성을 확인하였다. 결과; 8.5% (18/211)의 환자에서 눈의 이상이 발견되었고, 유착방지제와 안과적 합병증이 통계적 연관성을 보였다(p=0.020). 결론; 수술부위의 유착방지를 위해 사용되는 유착방지제에 젤라틴과 키토산 성분이 포함되어 알레르기 반응을 일으켜 안과적 합병증을 발생시킬 수 있을 것으로 생각된다.

• 공업화학
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• 제32권4호
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• pp.371-378
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• 2021

고체 표면의 박테리아 부착억제를 목적으로 고분자를 이용한 친수성 표면 개질 연구가 주목을 받고 있다. 부착억제기능은 세포독성이 아닌 작용으로 바이오필름 형성의 초기단계 방지를 목적으로 하며 친수성 또는 이온성 고분자가 도입된 고체 표면은 단백질, 박테리아 등 생물 개체의 부착방지에 효과적이다. 이는 표면에서의 친수층 형성으로 인한 표면 장벽 형성, 고분자 사슬에 의한 반발력과 삼투압성 응력 작용, 그리고 이온성 고분자와 세포 표면의 정전기적 상호작용에 기인한다. 부착억제를 위한 고분자의 표면 도입은 주로 표면 기능기와의 결합을 이용한 접합 방식과 자연모방 접착 기능기를 활용한 침적 방식으로 이루어지고 있다. 본 총설에서는 표면 도입 시 부착억제 기능을 보이는 대표적인 고분자의 종류, 코팅방법, 및 항균 특성을 소개하고 향후 공공시설, 산업 등으로의 대면적 응용을 위한 고려사항들을 다루고자 한다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권1호
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• pp.40-47
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• 2002

This paper describes a re-adhesion control method for the Korean High-Speed Train (KHST) with parallel induction motor drive. To keep a traction efficiency and to improve vehicle maintenance, the adhesion characteristics between wheel and rail are analyzed. Also the re-adhesion controller is designed as the subsystem of induction motor vector control. In order to verify performance of the proposed control techniques, the simulation is executed by train model and a downscaled re-adhesion control simulator is utilized. Both simulation and running test results show that good re-adhesion characteristics are obtained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2423-2425
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• 2004

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has slip state. First of all, this paper models adhesion characteristics and slip in wheeled robot. Secondly, the paper proposes estimation method of adhesion force coefficient(AFC) according to slip velocity. In order to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. The paper proposes an anti-slip control system based on an ordinary disturbance observer, that is, the re-adhesion control is achieved by reducing the driving torque enough to give maximum adhesion force coefficient. fuzzy logic controller(FLC) is petty useful with slip through that compare fuzzy with PI control for the controller performance. These procedure is implemented using a Pioneer 2-DXE parameter.

• Journal of Korean Neurosurgical Society
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• 제59권3호
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• pp.250-258
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• 2016

Objective : A common cause of failure in laminectomy surgery is when epidural, peridural, or perineural adhesion occurs postoperatively. The purpose of this study is to examine the efficacy of a temperature-sensitive, anti-adhesive agent (TSAA agent), Guardix-SG$^{(R)}$, as a mechanical barrier for the prevention or reduction of peridural scar adhesion in a rabbit laminectomy model. Methods : Twenty-six mature rabbits were used for this study. Each rabbit underwent two separate laminectomies at lumbar vertebrae L3 and L6, left empty (the control group) and applied 2 mL of the TSAA agent (the experimental group), respectively. Invasive scar formation or inflammation after laminectomy was quantitatively evaluated by measuring the thickness of the dura, the distance from the surface of dura to the scar tissues, the number of inflammatory cells in the scar tissues at the laminectomy site, and the concentration of collagen in histological sections. Results : At 6 weeks postsurgery, the dura was significantly thinner and the distance from the surface of dura to the scar tissues was greater in the experimental group than in the control group (p=0.04 and p=0.01). The number of inflammatory cells was not significantly different in the two groups (p=0.08), although the mean number of inflammatory cells was relatively lower in the experimental group than in the control group. Conclusion : The current study suggests that the TSAA agent, Guardix-SG$^{(R)}$, could be useful as an interpositional physical barrier after laminectomy for the prevention or reduction of adhesion.

• 전력전자학회논문지
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• 제8권4호
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• pp.366-374
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• 2003

본 논문에서는 최대 견인력 제어를 위해서 부하 토크 외란 관측기를 이용하여 점착력 계수를 추정하고 추정한 점착력 계수의 미분치를 PI 토크 제어하는 Anti-slip 제어를 제안한다. 부하 토크 외란 관측기는 회전자의 위치 정보와 토크 전류의 정보를 이용하여 부하 외란 토크를 추정하고, 부하 외란 토크에 철도차량 상수를 미용하여 점착력 계수를 추정한다. 또한 부하토크외란 관측기는 구조가 간단하며, 시스템의 외란 및 각종 제어이득. 시스템의 상수 변화에 대해서도 견실한 견인력 제어 특성을 가지고 있다. 이와 같은 제어 알고리즘을 구현하기 위하여 IC4M(1-Controller 4-Motor) 축소형 철도차량시스템을 이용하여 제안된 알고리즘을 시뮬레이션과 실험을 통하여 확인하였다. 또한 실제 철도차량시스템의 경우 선로 표면의 상태 변화 및 차량속도의 가감에 따른 공전속도에 대한 점착력의 관계를 축소형 철도차량시스템으로 구현하여, 실제 철도차랑시스템의 경우와 비교 분석하여 최대 견인력제어가 되도록 하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.626-631
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• 2004

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.

• 한국철도학회논문집
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• 제8권3호
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• pp.216-221
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• 2005

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the wright of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control based on disturbance observer and sensor-less vector control. The numerical simulation and experimental results point out that the proposed re-adhesion control system has the desired driving wheel torque response for the tested bogie system of electric coach. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.