• PNF and Movement
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• 제3권1호
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• pp.1-15
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• 2005

Objective : The purpose of this study was to evaluate the influence of a community based group exercise intervention on motor functional capacity. To evaluate the immediate(post-treatment) effects after 6-weeks exercise program on the group exercise intervention(PNF and Circuit exercise). Methods : Subjects-Included persons with stroke who were living in the community. Thirty-seven subjects were randomly assigned to the PNF, Circuit exercise and control group participated in a repeated measures design that evaluated the subjects with pre-treatment, post-treatment(6 weeks). Functional ability outcome measures assessed the motor assessment scale(MAS) and EMG. Both treatment groups participated in exercise cJass three times a week for 6 weeks. Group programs focused on balance, functional motor capacity and walking ability. The PNF program was modified PNF pattem and techniques with emphasis on functional tasks when possible, as well as stretching of the more affected limb particularly in the more affected shoulder. The Circuit program with subjects completing practice at a selies of work station as well as participating in walking races and relay with other members of the group. Results : Compared with the control group, the treatment group had larger improvements in the motor function ability after 6 weeks treatment and Post-treatment test scores were more significant than the pre-treatment score. 1. Motor function were assessed by using MAS, sit to stand, walking and upper function were assessed pre-treatment versus post-treatment measures revealed a statically significant(p<.05). There were significant differences between the groups. Compared with the control group, the treatment group had larger improvements. 2. In the treatment groups, demonstrated difference in the electromyographic activation of biceps, triceps, quadriceps and tibialis anterior muscles on the paretic side in the response to the reaching arm movement and stepping motion in stance. The difference in muscle activation improvement were not statically significant. Conclusion : The results of this study showed that the PNF and Circuit group exercise intervention can improve motor functional ability. This study suggests that the PNF and Circuit exercise programs is appropriate for community-based group exercise principles. It leads to gain and maintain potential function for disabled persons after stroke in the community.

• The Korean Journal of Pain
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• 제18권2호
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• pp.118-123
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• 2005

Background: A nerve ligation injury may produce a tactile allodynia. The effects of intrathecally delivered lamotrigine on allodynia induced due to fifth and sixth lumbar spinal nerves ligation in rats, using lumbar intrathecal catheters were examined. Methods: Sprague-Dawley rats (body weight 160-180 g) were prepared by tightly ligating the fifth and sixth left lumbar spinal nerves, with the implantation of a chronic intrathecal catheter for drug administration. Mechanical allodynia and allodynic threshold were measured using von Frey filaments and the updown method, respectively. After the baseline hind paw withdrawal thresholds had been obtained, lamotrigine (10, 30, 100 and $300{\mu}g$) was administered intrathecally. Thereafter, the dose-response curves and 50% effective dose ($ED_{50}$) were obtained. Motor dysfunction was assessed by observing the righting/stepping reflex responses and abnormal weight bearing. Results: Intrathecal administration of lamotrigine produced a dose-dependent antiallodynic action ($ED_{50}=61.7{\mu}g$). Mild motor weakness was observed with $300{\mu}g$ lamotrigine, but no severe motor impairment was found. Conclusions: It is suggested that intrathecal lamotrigine could produce moderate antagonism of mechanical allodynia at the spinal level in a rat neuropathic pain model with minimal motor weakness.

• 인지과학
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• 제23권1호
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• pp.109-132
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• 2012

최근 체화된 인지 접근에 따르면 행위의 이해는 추상적인 기호 처리가 아니라 그 행위와 관련된 감각-운동 정보의 심적 모사(mental simulation)를 통해 이루어진다고 주장되고 있다. 이 주장을 지지하는 증거로서 제시된 운동공명효과(motor resonance effect)는 관찰되는 행위와 현재 수행하는 행위 사이의 유사성에 의해 행위자의 운동 반응에 일어나는 간섭 혹은 촉진 효과를 말한다. 본 연구에서는 이러한 운동공명효과가 복잡한 사회적 행위를 지각하는 상황에서도 일어나는지 그리고 사회적 행위의 해석 관점에 따라 그 효과가 어떻게 달라지는 지를 알아보고자 하였다. 이를 위하여 어떤 행위자가 세 가지 신체 부위(팔, 발, 입)를 사용하여 다른 사람과 다투는 행위 장면을 그림으로 묘사하고, 각 그림을 행위자의 관점에서 기술하거나(예, 간호사가 의사를 때렸다/밟았다/물었다), 피행위자의 관점에서 기술하여(예, 의사가 간호사에게 맞았다/밟혔다/물렸다), 행위 사건 지각의 관점을 조절하였다. 실험 1에서는 실험참가자로 하여금 제시된 그림과 문장이 일치하면 페달을 밟거나 혹은 버튼을 누르는 행동 반응을 하도록 지시함으로써, 발 행위의 운동공명효과를 측정하였고, 실험 2에서는 마이크와 버튼을 이용하여 입 행위에 대한 운동공명효과를 측정하였다. 실험 1의 결과, 페달을 밟는 발 행동 반응이 발 행위 장면을 행위자의 관점에서 능동적으로 해석한 경우 다른 행위 지각 조건에 비해 빨라졌으며, 피행위자 관점에서 수동적으로 해석한 경우에는 오히려 느려졌다. 이와 유사하게, 실험 2에서는 마이크에 '합'이라는 소리를 내는 입 행동 반응이 입 행위 장면을 행위자가 상대방을 무는 행위로 능동적으로 해석한 경우 빨라졌으며, 같은 장면이라도 피행위자 관점에서 기술하였을 때는 오히려 느려졌다. 본 연구의 결과는 일상생활에서 사회적 행위를 지각하는 과정에서도 운동공명효과는 일어날 수 있다는 것과, 그러나 그 효과 또한 행위 사건을 해석하는 관점에 따라 조절될 수 있다는 점을 시사한다.

• 한국정밀공학회지
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• 제22권12호
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• pp.77-86
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• 2005

This paper is about the development of Automatic FPC(flexible printed circuit) punching instrument for the improvement of working condition and cost saving. FPC is used to detect the contact position of keyboard and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, The punching accuracy is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used fur the sake of cost down instead of using high quality vision systems for the factory automation. Test algorithms and programs showed good results to the designed automatic punching system and led to the increasement of productivity and huge cost down to law material like FPC by avoiding bad quality.

• 한국정밀공학회지
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• 제32권8호
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• pp.687-692
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• 2015

LAM (Laser-Assisted Machining) is an effective method for processing difficult-to-cut workpieces. The focal length of a LAM system is changed by the change of the workpiece shape during laser preheating; this problem is solved by changing the lens of the laser module. Linear- and rotary-type lens changers were developed to change the laser lens of a LAM system. The linear-type lens changer is operated by a motor with a ball-screw, and the rotary type is operated by a stepping motor. The natural frequency and structural stability of the laser lens changers were confirmed by using a finite element analysis; in addition, the functions of the lens changers were verified by measuring the iterative accuracy. The measured results show that the rotary-type lens changer is more accurate than the linear-type changer.

• 제어로봇시스템학회논문지
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• 제20권3호
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• pp.323-332
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• 2014

Stepper motor is widely used in positioning applications due to its durability and high torque to inertia ratio as well as low cost and ability to be easily controlled with open-loop. Due to increased resolution of position control and improved stability of motion control, microstepping has drawn attention in industry since it was introduced in 1970s. With the increase in computational power and decrease in cost of embedded processors in recent years, drives and control systems for stepper motors have become more sophisticate than ever. Thus, closed-loop control methods have been developed to improve the performance of the stepper motors. In this paper, we review not only basic principles of conventional control methods used for stepper motors but also that of microstepping control. In addition, we surveyed recent development in nonlinear control methods applied to stepper motors. The nonlinear control methods are presented in the view of Lyapunov stability. Nonlinear torque disturbance observer, sliding mode control, and nonlinear phase compensation are also presented.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제23회 추계학술대회 논문집
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• pp.251-254
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• 2004

하이브리드 로켓은 고체, 액체 로켓과 비교하여 많은 장점을 가지고 있다. 하이브리드 로켓은 액체 로켓에 비해 구조적으로 단순하고 비용도 저렴하지만 액체 로켓과 유사한 $I_{sp}$를 발휘한다. 또한 고체 로켓에서는 불가능한 엔진 소화$\cdot$재점화가 가능한 장점을 가지고 있다. 하이브리드 로켓의 추력은 산화제의 유량에 비례하여 증가한다. 본 연구에서는 소형 하이브리드 로켓을 설계 제작하여 실험을 수행하였다. 전체 시스템은 하이브리드 로켓 연소기, 점화장치, 유량 조절장치 그리고 데이터 획득 장치로 구성하였다 산화제의 유량을 조절하기 위해 니들 밸브와 스텝 모터를 결합하였다.

• 한국기계가공학회지
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• 제20권2호
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• pp.38-44
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• 2021

To cater to the transition from single-color to multicolor/multi-material printing, this paper proposes a cartridge-replacing type multi-nozzle Fused Depositon Modeling(FDM) three-dimensional (3D) printer. In the test printing run, tool change failure/wobble/layer shift occurred. It was confirmed that improper support was the cause of this tool change failure. As a solution, spline and electromagnetic cartridges were designed. Wobble was caused by machine vibration and the motor stepping out. To minimize wobble, an additional Z-axis was installed, and the four-point bed leveling method was used instead of the three-point bed leveling method. The occurrence of layer shift was ascribed to the eccentricity of the Z-axis lead screw. Therefore, slit coupler was replaced with an Oldham type. In addition to the mechanical supplementation, the control environment was integrated to prevent accidents and signal errors due to wire connections. Before the final test printing run, a rectifier circuit was added to the motor to secure precise control stability. The final test printing run confirmed that the wobble/layer shift phenomenon was minimized, and the maximum error between layers was reduced to 0.05.

• 인지과학
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• 제27권4호
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• pp.573-597
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• 2016

최근 행위 개념의 신경적 표상에 대한 fMRI나 EEG 연구들은 행위 개념의 처리가 감각-운동 정보의 모사(simulation)를 불러일으킨다고 주장한다. 이와 아울러 행위동사나 행위 문장 이해가 현재 수행해야 하는 행위를 간섭하거나 촉진시킨다는 행동연구들도 존재한다. 그러나 행위 개념 처리와 현재 행동 수행간의 실시간 상호작용이 감각-운동정보의 모사를 매개로 하는지, 또 다른 기전에 바탕을 두는지 아직까지 분명하지 않다. 본 연구에서는 행위 언어 지각이 어떻게 현재 행위 수행에 영향을 주는지 그 기저에 있는 신경 메커니즘을 시공간적으로 탐색하고자 시간해상도가 높은 뇌파 측정과 다중전류원분석이라는 뇌파분석 기법을 사용하였다. 이를 위하여 실험참가자에게 단서 자극 색상에 따라 손으로 버튼 누르기 행동과 발로 페달 밟기 행동을 해야 하는 단서-운동반응 과제를 수행하도록 하였고, 단서가 제시되기 직전에 반응 행위자체를 기술하는 행위동사(즉, 눌러라, 밟아라, 멈춰라)를 청각적으로 제시하여 행위동사와 반응 행동 간의 의미 일치성에 따른 상호작용을 관찰하였다. 반응시간 분석 결과, 손으로 버튼을 누르는 반응행위와 발을 이용하여 페달을 밟는 반응행위 모두에서 행위동사와 반응행위가 일치하는 경우 촉진효과가 관찰되었고, 불일치에 따른 간섭효과는 손 행위에서 나타났다. 전류원 파형 분석결과, 행위동사와 반응행위간의 의미일치성 효과는 행위 동사 처리 기간에는 베르니케 영역, 운동단서 제시 시점에선 전대상회와 보조운동영역, 운동수행 시점에서는 보조운동영역과 일차운동피질에서 통계적으로 유의한 차이가 관찰되었다. 현재 결과로는 행위동사가 특정 운동피질을 활성화시켜 이를 매개로 현재 행위에 영향을 준다고 하기보다, 뒤따르는 행위를 예측하고 이를 준비하는 과정에 영향을 미쳐, 촉진/간섭효과를 가져오는 것으로 보인다. 마지막으로 본 연구가 가지는 행위 개념의 신경학적 표상에 대한 함의와 연구 방법론상 한계에 대해 논의하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권2호
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• pp.127-131
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• 2004

A low-cost, simple strip reader system using a linear movement mechanism of CD-ROM deck has been developed to characterize a lateral flow membrane-based immunochromatographic assay. The test strip reader was assembled by a CD-ROM deck and home-made optical head especially designed for immunoassays. The optical head for detecting reflected light from the test strip surface consists of green light-emitting diode, large area silicon photodiode, and anodized aluminum mounting block providing a slit structure for cutting light from the LED. The stepping motor of the deck was operated in the full step mode, whose distance of each reading point is about 0.15mm. The performance of the strip reader was tested by analysis of HBV(hepatitis B virus) antigen test kit. This strip reader can be useful for inexpensive, disposable, and membrane-based assays that provide visual evidence of the presence of an analyte in a liquid sample.