• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.446-452
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• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes a voltage control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1448-1450
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• 2004

Now a day, the Korean National Railroad is laking new agewith the opening of KTX (Korea Train Express). Korean National Railroad is planning using the GSM-r for put KTX and existing equipment to a good. GSM-R is radio communication method selected by ERTMS (European Rail Traffic Management System). So a new algorithm for train movement is necessary to radio communication form. This paper is come up with an algorithm for like that situation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.543-550
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• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes an adaptive control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• 한국항행학회논문지
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• 제19권1호
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• pp.41-47
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• 2015

최근 국내에서 A-SMGCS (advance surface movement ground control systems) 레벨 IV단계를 구현하기 위한 연구가 활발히 진행 중에 있다. 전체 A-SMGCS 시스템의 안전을 확보하기 위하여 안전성 평가가 필요하며, 유로컨트롤에서는 A-SMGCS의 안전성 평가를 위하여 기능별 위험요소 평가, 예비시스템 안전성 평가, 그리고 시스템 안전성 평가를 수행하도록 권고하고 있다. 본 논문에서는 기능별 위험요소 평가 방법을 통하여 전체 A-SGMCS의 위험요소를 식별한다. 따라서 A-SMGCS레벨 IV시스템에 대하여 29가지 위험 요소를 식별하고 각 위험요소의 심각도를 평가하는 자료로 활용할 것이다.

• 방송공학회논문지
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• 제22권2호
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• pp.234-239
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• 2017

본 논문에서는 비디오 영상내 사물의 움직임의 방향과 크기의 변화를 이용한 새로운 서술자를 정의하고 이를 기반으로 하여 실시간으로 폭력 영상을 검출하는 방법을 제안한다. 새로 정의된 서술자는 폭력 행위의 움직임의 크기 및 방향 변화량이 일반적인 움직임에 비해 매우 크다는 관찰에 착안한 것이다. 일정한 프레임 동안의 서술자 값으로 이루어진 서술자 특징 벡터를 얻었고, 이것은 SVM(Support Vector Machine)으로 학습된 분류기를 통하여 폭력행위와 비폭력행위를 구별하는 데에 사용되었다. 제안하는 방법의 성능을 검증하기 위해 ViF(Violent Flow) 알고리즘과 세 종류의 데이터셋을 이용하여 비교 실험을 수행하였고, 모든 경우에서 더 우수한 성능을 보임을 확인하였다.

• Physical Therapy Rehabilitation Science
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• 제10권3호
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• pp.257-262
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• 2021

Objective: Patients with stroke generally diminished ankle range of motion, which decreases balance and walking ability. This study aimed to determine the effect of ankle self-mobilization with movement (s-MWM) on ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index in patients with chronic stroke. Design: Randomized controlled trial design Methods: Twenty-four post-stroke patients participated in this study. The participants were randomized into the control (n = 12) and self-MWM groups (n = 12). Both groups attended standard rehabilitation therapy for 30 minutes per session. In addition, self-MWM group was performed 3 times per week for 8 weeks. All participants have measured ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index in before and after the intervention. Results: After 8 weeks of training, self-MWM group showed greater improvement in ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index than in the control group (p<0.05). Further, self-MWM group had significantly improvement in all dependent variables compared to the pre-test (p<0.05). Conclusions: Our investigation demonstrates that self-MWM is beneficial for improving functional ability. Also, self-MWM was superior to control with respect to improving ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.270-272
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• 2005

In this paper, we proposed a new method detecting actions of some components driven by the coil excitation. Nuclear power reactors are typically controlled by the movement of several neutron-absorbing control rods into or out of the reactor core. For moving control rods, we use an electromagnetic-jack-typed mechanism, which is called Control Rod Drive Mechanism. This mechanism moves control rods by the step composed of sequential actions of components. In case any mechanical problems happen in the mechanism, the orders for the control rod movement from the higher system cannot be performed properly. This abnormal state must be monitored and the sequential actions of the components can be the monitoring target. The actions of components generate some deviations in the profiles of the currents flowing into the coils in the mechanism. We focused on this phenomena and devised a new method of detecting the actions of the components in Control Rod Drive Mechanism by using the wavelet transform for observing the current profile.

• 한국태양에너지학회 논문집
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• 제33권2호
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• pp.84-92
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• 2013

Blinds are a common type of shading device and are increasingly operated automatically to overcome the limitations of manual operation. Automated blinds need to be controlled to maximize benefits of daylight in the point of occupant comfort and energy consumption. However, the previous control methods could cause occupant's distractions by the undesirable control time interval and amount of blind movement. A few researches suggested the control concept for minimizing occupant's distractions by automatic blind control, but they did not provide optimal control algorithm to be useful in practice. In this paper, we propose an optimal control algorithm for automated blinds that can maximize not only visual comfort but also sunlight penetration into buildings based on occupants' preferences on blind movement and sunlight. The proposed control algorithm can prevent solar glare on workplane and minimize occupant's distractions to maximize occupants' visual comfort.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.555-558
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• 2003

When a fault relating to the urgent alarm occurs, we must prevent control rods from dropping and make one of two grippers in Control Rod Drive Mechanism (CRDM) grip the drive rod laking a control rod assembly. If a gripper with any problem is ordered to grip the drive rod, the gripper which cannot latch the rod stably will fail to take the rod. On the purpose of escaping this bad case, we order two grippers to hold the drive rod and enhance the reliability of holding control rods. This action is called the double hold. In the middle of the movement of the drive rod, the latching of the drive rod can cause friction between a gripper and the drive rod. This state may give damage to both the gripper and the drive rod. In this paper, we have devised the method which can have two grippers hold the drive rod more stably, without damaging the equipment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.684-689
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• 2007

The aim of this study is to examine the change of the osteoclastic activity in the surrounding bone with or without tooth movement after corticotomy by histologic study. Eighteen male Sprague Dawley rats with an average body weight of 300 g(range 250-350 g) were used. The rats were divided into three groups of six animals. They were operated corticotomy-assisted tooth movement and killed after 1 week, 2 weeks, and 3 weeks after tooth movement. Corticotomy was done in the surrounding of the both upper first molar. A split mouth design was used by referring to the contralateral side as control. After flap suturing, the upper left first molar was moved anteriorly by closed coil spring. The force applied was 1 N. The average of tooth movement of the 1 week group was $0.24{\pm}0.09mm,\;0.20{\pm}0.26mm$ in 2 weeks group and $0.41{\pm}0.39mm$ in 3 weeks group, respectively. The difference between the 1 week and the 2 weeks groups was very small to compare with the 3 weeks group. In the treatment group, the average numbers of cells that positively reacted to TRAP were 14.5 in the 1 week group, 12.0 in the 2 weeks group, and 6.0 in the 3 weeks group. In the control group, the numbers were 8.3 in the 1 week group, 12.8 in the 2 week group, and 1.5 in the 3 week group, respectively. The amount of tooth movement of the 3 week group was about twice as large as those of the 1 week and 2 week groups. From the standpoint of histology, the average number of cells that positively reacted to TRAP was initially larger in the treatment group than in the control group, similar in both group in 2 weeks, and became less in the treatment group in 3 weeks. Additionally, in the control group, their activity of osteoclast was higher in 2 weeks than in 1 week, and decreased rapidly in 3 weeks.