• 대한기계학회논문집
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• 제18권12호
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• pp.3253-3269
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• 1994

In this paper a new concept, named the Extended Operational Space Formulation, has been proposed for the effective analysis and real-time control of the robot manipulators with kinematic redundancy. The extended operational space consists of operational space and optimal null space. The operational space is used to describe robot end-effector motion; whereas the optimal null space, defined as the target space of the self motion manifold, is used to express the self motion for the secondary tasks. Based upon the proposed formulation, the kinematics, statics, and dynamics of redundant robots have been analyzed, and an efficient control algorithm has been proposed. Using this algorithm, one can optimize a performance measure while tracking a desired end-effector trajectory with a better computational efficiency than the conventional methods. The effective ness of the proposed method has been demonstrated with simulations.

• 대한간호학회지
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• 제45권6호
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• pp.823-833
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• 2015

Purpose: The purpose of the study was to investigate the effects of the Thera-Band exercise program following total knee arthroplasty. Methods: The research design for this study was a nonequivalent control group non-synchronized design. Participants were 30 patients for the experimental group and 30 patients for the control group. The experimental group participated in the Thera-Band exercise program in addition to conventional CPM (continuous passive motion) exercise. The control group received conventional CPM exercise only. Outcome measures were pain, knee flexion range of motion, CRP, and psychological parameters (self-efficacy and fear of falling). Data were analyzed using ${\chi}^2$-test, Fisher's exact test, t-test, and repeated measure ANOVA with SPSS/PC version 21.0. Results: There were significant improvement in self-efficacy, and decreases in pain, and fear of falling in the experimental group compared to the control group. However, no significant differences were found between the two groups for CRP and knee flexion ROM. Conclusion: The Thera-Band exercise program gave an additional benefit over the conventional CPM exercise for patients following total knee arthroplasty, and is recommended for use as an effective nursing intervention for patients after total knee arthroplasty.

• Journal of Yeungnam Medical Science
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• 제39권2호
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• pp.81-88
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• 2022

Vertigo is the sensation of self-motion of the head or body when no self-motion is occurring or the sensation of distorted self-motion during an otherwise normal head movement. Representative peripheral vertigo disorders include benign paroxysmal positional vertigo, Ménière disease, and vestibular neuritis. Vestibular neuritis, also known as vestibular neuronitis, is the third most common peripheral vestibular disorder after benign paroxysmal positional vertigo and Ménière disease. The cause of vestibular neuritis remains unclear. However, a viral infection of the vestibular nerve or ischemia of the anterior vestibular artery is known to cause vestibular neuritis. In addition, recent studies on immune-mediated mechanisms as the cause of vestibular neuritis have been reported. The characteristic clinical features of vestibular neuritis are abrupt true-whirling vertigo lasting for more than 24 hours, and no presence of cochlear symptoms and other neurological symptoms and signs. To accurately diagnose vestibular neuritis, various diagnostic tests such as the head impulse test, bithermal caloric test, and vestibular-evoked myogenic potential test are conducted. Various treatments for vestibular neuritis have been reported, which are largely divided into symptomatic therapy, specific drug therapy, and vestibular rehabilitation therapy. Symptomatic therapies include generalized supportive care and administration of vestibular suppressants and antiemetics. Specific drug therapies include steroid therapy, antiviral therapy, and vasodilator therapy. Vestibular rehabilitation therapies include generalized vestibular and customized vestibular exercises.

• 대한정형도수물리치료학회지
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• 제28권2호
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• pp.67-75
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• 2022

Background: Scapular winging is a rare disorder that is commonly caused by nerve damage of the dorsal scapular nerve, spinal accessory nerve, or the long thoracic nerve. This affects the scapulohumeral rhythm which may cause abnormal kinetic motion of the shoulder. The purpose of this case report is to describe a self-exercise oriented management incorporating shoulder strengthening to reduce symptoms in a shoulder pain patient with winging scapular. Methods: A 45 year old male patient complained of pain in his both shoulders without any trauma. Shoulders were treated with steroid injections for supraspinatus tendonitis, but although pain improved to some extent, pain and disability continued for 3 months. Both shoulders had pain, decreased active range of motions, muscles weakness, and scapular winging. The patient underwent 9 interventional sessions over 3 months and was managed mainly by self-exercise. The intervention method involved push up plus, sling, muscle strengthening, and stabilization exercises. Loads were increased as symptoms improved. Results: Clinical outcomes were measured at every session. Pain in both shoulders reduced to 0 on a numerical pain rate scale by the 4th session, and the active range of motion was fully recovered. During the 9th session, the strength of the serratus anterior had improved from grade P to G on the right side and grade G to N grade on the left. Conclusion: In this case study, the self-exercise program was effective in reducing pain, increasing active range of motion, and improving muscle strength in subjects with scapular winging.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.854-857
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• 2001

At present, colonoscopy is performed by means of quite long and flexible endoscopes and controlled manually. Although the flexibility of the distal tip allows the endoscope to follow the tortuous path of the colon, the insertion of the endoscope requires the endoscopist to exert forces on and to perform rotations of the proximal end; these actions cause discomfort to the patient. Though self-propelling colonoscopic systems has been suggested to overcome these problems, it is difficult to pass through highly curved regions of the intestine. In this paper, we introduce a steering mechanism for a self-propelling coloinlscope, the smart capsule, which has three actuator units. The mechanism is designed not only to move forward and backward but also to pass through the curved regions. We derived the governing equations of this mechanism. Active movements and motion control are developed.

• Korean Journal of Mathematics
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• 제11권1호
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• pp.35-43
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• 2003

We study the weak convergence to Fractional Brownian motion and some examples with applications to traffic modeling. Finally, we get loss probability for queue-length distribution related to self-similar process.

• 한국항해항만학회지
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• 제34권3호
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• pp.195-203
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• 2010

본 논문은 통합채광시스템의 동력학 해석을 다루고 있다. 통합채광시스템은 채광선, 수직양광관, 중간 저장 장소인 버퍼, 유연관, 자항식집광기로 구성되어 있다. 자항식집광기와 버퍼는 6자유도의 강체로 가정하였으며, 수직양광관과 유연관의 동적거동 해석을 위해 집중질량 매개방법을 이용한 이산화 모델을 적용하였다. 채광선에 대한 운동은 포함시키지 않았지만 경계조건을 통하여 채광선의 움직임을 표현하였다. 연약한 해저면을 주행하는 차량에는 연약지반 역학 모델을 적용시켰다. 수직양광관-버퍼, 버퍼-유연관, 유연관-자항식집광기의 연결에는 회전구속과 볼 구속조건을 사용하였다. 연성 동력학 모델의 운동방정식을 유도하기 위해 국부좌표계를 사용하였으며, 4개의 오일러 매개변수를 사용하여 각 시스템의 자세를 표현하였다. 통합 채광시스템의 운동 방정식 해를 구하기 위해서 증분-반복법을 적용하였으며, 시간영역 적분기는 newmark-${\beta}$를 사용하였다. 통합 채광시스템의 동적 거동 해석을 수치해석을 통해 분석하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권2호
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• pp.136-144
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• 2014

The existing conventional motion controller does not perform well in the presence of nonlinear properties, uncertain factors, and servo lag phenomena of industrial actuators. Hence, a feasible and effective fuzzy self-tuning proportional integral derivative (PID) and feed-forward control scheme is introduced to overcome these problems. In this design, a fuzzy tuner is used to tune the PID parameters resulting in the rejection of the disturbance, which achieves better performance. Then, both velocity and acceleration feed-forward units are added to considerably reduce the tracking error due to servo lag. To verify the capability and effectiveness of the proposed control scheme, the hardware configuration includes digital signal processing (DSP) which plays the main role, dual-port RAM (DPRAM) to guarantee rapid and reliable communication with the host, field-programmable gate array (FPGA) to handle the task of the address decoder and receive the feed-back encoder signal, and several peripheral logic circuits. The results from the experiments show that the proposed motion controller has a smooth profile, with high tracking precision and real-time performance, which are applicable in various manufacturing fields.

• 제어로봇시스템학회논문지
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• 제5권4호
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• pp.454-461
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• 1999

A concrete floor trowel machine, developed in the U.S in 1990's, consists of only two rotary trowels, and doesn't need any other mechanism for motion such as wheels. When the machine flattens a concrete floor with its rotary trowels, the machine can move in any direction by utilizing the unbalanced friction forces occurring between the rotary wheels and the floor when the trowels are tilted in appropriate directions. In order to automate the trowels machine, this paper proposed the self-propulsive concrete finishing trowel robot which has twin trowels. For the control of the robot, this paper discussed the following. Firstly, the dynamics model of the driving frictional force applied on each trowel from the floor is derived. Secondly, the relationship between the driving force for the robot and the control variable of the robot is derived. Finally, the basic motion of the robot are realized by using the obtained relationship. This paper figures out how the concrete floor finishing robot with tow trowels moves and will contribute to realizing it.

• 로봇학회논문지
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• 제11권4호
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• pp.193-204
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• 2016

This paper presents an anthropomorphic finger prosthesis for amputees whose proximal phalanx is mutilated. The finger prosthesis to be proposed is able to make the amputees to perform the natural motion such as flexion/extension as well as self-adaptive grasping motion as if normal human finger does. The mechanism of finger prosthesis with three degrees-of-freedom (DOFs) consists of two five-bar and one four-bar linkages. Two passive components composed of torsional spring and mechanical stopper and only one active joint are employed in order to realize an underactuation. Each passive component is installed into the five-bar linkage. In order to activate the finger prosthesis, it is required for the user to flex and extend the remaining proximal phalanx on the metacarpophalangeal (MCP) joint, not an electric motor. Thus the finger prosthesis conducts not only the natural motion according to his/her intention but also the grasping motion through the deformation of springs by the object for human finger-like behavior. In order to reveal the operation principle of the proposed mechanism, kinematic analysis is performed for the linkage design. Finally both simulations and experiments are conducted in order to reveal the design feasibility of the proposed finger mechanism.