• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.327-329
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• 2000

This paper present the characteristic improvements of one-coil coin type vibration Motor. Rotor is consist of coreless coil and 4 segment commutator. Magnet is 4 pole, z direction magnetized. This one-coil coin type vibration motor has simple mechanical structure and good efficiency. So production cost is lower than other having 2 or more coils coin type motor but it has the weak points. That is small vibration magnitude and dead zone. Modifying the shape of rotor, vibration magnitude is increased. To avoid the dead zone we attached more magnetic body on rotor. As result we show the optimal position of magnetic body.

• 한국정밀공학회지
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• 제26권6호
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• pp.114-121
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• 2009

Mobile phone is a representative personal communication tool among wireless communication devices. Recently, with the miniaturization and light-weight trend of mobile phone, the vibration motor has been replaced by coin type. The required performances of coin type vibration motor needed by user are long life, higher vibration, and thin thickness. Also the most important factor determines the performance of vibration motor is long-term reliability, which is mainly related to PCB plating technique for commutator. In this study, three types of fault were categorized to analyze the cause for malfunction of vibration motor. And, hardness and surface morphology on plating surface are also investigated to optimize the plating method and plating conditions. As a result, new plating method and conditions were proposed to increase the durability of PCB commutator.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.218-223
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• 2008

Cell-phone becomes a necessary communication device in modern society. However, a paging signal by a sound transducer often acts as an unpleasant noise, thus necessitating a paging signal by a vibration motor. The conventional flat type vibration motor uses three-phase windings with three phase coils. In this article, a new design of a vibration motor using a V connection with two phase coils is presented, increasing mass productivity. For electromagnetic field analysis, due to the motor symmetry, two-dimensional modeling can be implemented for fast computation, and performance is predicted by the finite element method. The winding distribution angle turns out to be the most important design parameter for the elimination of dead points, and a new coil configuration is suggested which has no adverse effect on motor size and weight. Experimental tests of vibration confirm the validity of the proposed design.

• The Journal of Korean Physical Therapy
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• 제17권2호
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• pp.67-87
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• 2005

Impaired sensorimotor function of the hand ipsilateral to a unilateral brain damage has been reported in a variety of motor task. however, it is still the controversial issue because of the difficulty of detection in clinical situation, patients' variability(time after onset, contralateral upper extremity severity, other cognitive functions including apraxia), and the performed various motor task. The purpose of this study is to determine the presence of ipsilateral motor deficit following unilateral brain damage in three different specific tasks(hand tapping, visual tracking and coin rotation) compared with healthy age-sex matched control group using the same hand and to investigate the lateralized motor control in each hemispheric function. Findings revealed that stroke patients with unilateral brain damage experienced difficulties with rapid-simple repetitive movement, visuomotor coordination, complex sequencing movement on ipsilateral side. Also, Comparison of the left-hemispheric stroke groups and the right-hemispheric stroke groups revealed that patients with a left-hemisphere damage tended to be more variable in performing all of the three tasks. These results show that stroke patient with left hemisphere damage has more ipsilateral motor deficit, and the left hemisphere contributes to the processing of motor control that necessary for the executing actions with ipsilateral hand.

• 기술혁신연구
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• 제23권4호
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• pp.245-287
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• 2015

아키텍처 혁신은 급진적 혁신과 달리 기술적 불연속성의 정도는 낮지만 제품 아키텍처의 변경을 통한 기술적 성능개선 폭은 큰 혁신으로 이해되고 있다. 신생 산업의 초기, 급진적 혁신 제품의 개발에 성공한 기업은 이후, 열등한 아키텍처 효율성 문제를 극복하지 않으면 더 이상 기술적 성능 개선이 둔화되는 시점에 도달하게 된다. 이 지점에서는 급진적 혁신 단계에서의 열등하지만 창의성이 깃든 제품 아키텍처의 창출 경험은 오히려 아키텍처 혁신의 장애물로 작용하게 될 수 있다. 본 연구는 아키텍처 혁신 전후의 시장 요구변화와 이에 대한 기술적 해결 전략을 단계모델의 관점과 문제해결 모델의 관점이 결합된 분석틀의 구축을 통해 이해해보고자 하였다. 한국의 중소기업 자화전자(주)는 산업 초창기 휴대폰에 장착되는 진동모터의 급진적 혁신에 성공 후 아키텍처 혁신과 연관된 장애물들을 극복함으로써 마침내 자신이 개발한 진동모터의 본격적 확산에 성공할 수 있었다. 본 연구는 진동모터의 개발과정에 대한 능동적 참여관찰을 통해 단일 사례를 종단적으로 깊이 연구함으로서, 이 과정이 어떻게 진행되었는지를 이해하고자 하였다.