• Journal of international Conference on Electrical Machines and Systems
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• 제1권2호
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• pp.23-29
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• 2012

The control of stator flux, torque angle, excitation torque, reluctance torque and total torque of the direct torque control (DTC) for a permanent magnet synchronous motor (PMSM) are studied in this paper. Simplified expressions to represent the changes of these variables due to the application of a voltage vector are given. Finally, a voltage vector selection area and the implementation of a voltage vector selection strategy are proposed.

• 한국정밀공학회지
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• 제25권9호
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• pp.86-94
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• 2008

A total stroke of an opening or closing motion of a hinge mechanism in a folder-type mobile phone is composed of two portions. In the first portion, human fingers act a force to open or close the folder. In this portion, the rotating folder compresses the coil spring installed in the mechanism. In the last portion, this compressed coil spring generates a torque to rotate the folder. The main merit of this study is that we have designed a hinge mechanism to be operated by a uniform torque in the first portion of the total stroke. The uniform torque means that it is constant along the folder's swing angle. This mechanism will give softer feeling to human fingers. A pair of contours in the mechanism plays an important role. It transforms rotation into translation in the first portion; on the other hand, it transforms translation into rotation in the last portion. In this study, we have developed an algorithm to obtain the pair of contour curves. We divided the total contour curves into finite sub-intervals. Assuming that the curves in every sub-interval are parabolas, we have obtained the coefficients of them by solving systems of nonlinear equations recursively.

• The Journal of Advanced Prosthodontics
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• 제13권3호
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• pp.136-143
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• 2021

Purpose. This study aimed to evaluate the effect of repeated use of an implant handpiece under an implant placement torque (35 Ncm) and overloading torque condition (50 Ncm) on an output torque. Materials and Methods. Two types of implant handpiece systems (Surgicpro/X-DSG20L [NSK, Kanuma, Japan] and SIP20/CRB46LN [SAESHIN, Daegu, South Korea]) were used. The output torque was measured using a digital torque gauge. The height and angle (x, y, and z axes) of the digital torque gauge and implant handpiece were adjusted through a jig for passive connection. The experiment was conducted under the setting torque value of 35 Ncm (implant placement torque) and 50 Ncm (overloading torque condition) and 30 times per set; a total of 5 sets were performed (N = 150). For statistical analysis, the difference between the groups was analyzed using the Mann-Whitney U test and the Friedman test was used to confirm the change in output torque (α=.05). Results. NSK and SAESHIN implant handpieces showed significant differences in output torque results at the setting torques of 35 Ncm and 50 Ncm (P<.001). The type of implant handpiece and repeated use influenced the output torque (P<.001). Conclusion. There may be a difference between the setting torque and actual output torque due to repeated use, and the implant handpiece should be managed and repaired during long-term use. In addition, for successful implant results in dental clinics, the output torque of the implant handpiece system should be checked before implant placement.

• 한국기계가공학회지
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• 제9권3호
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• pp.8-18
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• 2010

A total stroke of an opening or closing motion of a hinge mechanism for a folder-type mobile phone is composed of two portions. In the first portion, human fingers act a torque to open or close the folder. In this portion, the rotating folder compresses the coil spring installed in the hinge mechanism. In the last portion, this compressed coil spring generates a torque to rotate the folder. In this study, we have developed an algorithm to design a hinge mechanism to be operated by an arbitrary continuous torque in the first portion of the total stroke. Consequently, we can design hinge mechanisms that satisfy various demands of consumers. A pair of contours installed in the mechanism plays an important role. It transforms the folder's rotational motion into translation to compress the coil spring in the first portion; on the other hand, it transforms translational motion into the folder's rotation in the last portion. Using this algorithm we have designed the pair of the contour curves operated by an arbitrary continuous torque.

• 대한치과교정학회지
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• 제39권2호
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• pp.95-104
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• 2009

본 연구는 self-tapping screw의 특징적 구조인 cutting flute의 길이 및 형태 변화에 따른 미니 임플랜트의 식립 및 제거 토크를 비교해보기 위해 시행되었다. 외경, 내경, 길이 및 pitch 등 다른 조건이 모두 동일하고 cutting flute의 형태만 다른 세 종류의 미니 임플랜트를 사용하였다(A군; 2.6 mm 길이의 flute가 형성된 그룹, B군; 3.9 mm의 길이이면서 직선형의 flute를 갖는 그룹, C군; 3.9 mm의 길이이면서 나선형의 flute를 갖는 그룹). 골밀도를 균일하게 하기 위해 실험용 인공골(Sawbones Inc., USA)을 사용하였으며, 수직력 및 회전속도를 일정하게 하기 위해 구동식 토크시험기를 이용하였다. 그 결과 다음과 같은 결론을 얻었다. 총 삽입 시간은 2 mm 두께의 피질골 시편에서는 세 군간에 차이를 보이지 않으나, 4 mm 두께의 피질골 시편에서는 C군 > B군 > A군 순으로 짧은 삽입 시간을 보였다. 최대 삽입 토크는 2 mm 두께의 시편에서는 A군이 다른 두 군에 비해 높은 값을 보이나, 4 mm 두께의 피질골 시편에서는 C군 > A군 > B군 순으로 높은 값을 보였다. 최대 제거 토크는 2 mm 두께의 피질골 시편에서는 세 군 사이에 차이가 없으나, 4 mm 두께의 피질골 시편에서는 C군이 다른 두 군에 비해 높은 값을 보여주었다. 이상의 결과로 보아 피질골이 두꺼운 부위에 미니 임플랜트를 식립할 경우 cutting flute의 길이 및 형태 또한 고려하여 미니 임플랜트를 선택하는 것이 바람직하다.

• 한국운동역학회지
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• 제16권4호
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• pp.105-113
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• 2006

The purpose of this study was to analyze the joint torque of triple segmental system in golf driver swing. For this purpose, joint torque were calculated. In order to determine the load on the lumbar region, a triple segmental system was set for wrist, left shoulder and lumbar, torque working on the lumbar region were estimated. For this study, a total of 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint torque was generated in the direction opposite the target on wrist and shoulder during down swing, while in the direction towards the target on the lumbar region. During impact and release, the torque on the wrist joint was converted from the direction opposite the target to the direction towards the target, while the torque on the lumbar region was generated vice versa. The joints on the club-arm-shoulder were generated in the opposite direction at the beginning of down swing when the torque on the thorax-pelvis began to be generated, and then, the torque on the thorax-pelvis began to lower, while that on the club-arm-shoulder began to increase. Thus, a rapid decrease of the torque on the lumbar region linked to the low trunk acted to increase moment and joint torque on the arm-club region.

• 한국산업정보학회논문지
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• 제28권4호
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• pp.35-43
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• 2023

차세대 전기자동차에서는 전비 향상 및 주행 성능 개선을 위하여 각 휠에 의해 직접적으로 토크를 제어하는 인 휠 모터 시스템에 대한 연구가 진행되고 있다. 이에 따라 본 논문에서는 전기자동차 구동용 인 휠 모터에 적용되는 토크 벡터링 시스템에서 각 휠에 가해지는 토크를 분배하는 알고리즘에 대한 연구를 수행하였다. 차량의 주행 및 조향에 따른 실제 차량 특성 파라미터를 적용한 차량 모델을 구현하기 위해 MATLAB Simulink 환경에서 시뮬레이션을 진행하였으며 제안된 알고리즘에 따라 토크 분배가 이뤄지는 것을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권1호
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• pp.49-53
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• 2011

Introduction: This study compared the strength of osseointegration as determined by the resistance to reverse torque rotation of three different hydroxyapatite coated implants in the rabbit femur model. Materials and Methods: Three hydroxyapatite coated implants (HAPTITE), Tapered Screw-Vent (TSV) and BioTite-H - were used. A total of 40 implants were placed in the femur of 20 adult male rabbits. The animals were divided into two groups. In group A (n=10); one HAPTITE was placed into each right femur and one TSV was placed into each left femur. In group B (n=10); one HAPTITE was placed into each right femur and one BioTite-H was placed into each left femur. Five rabbits of each group were sacrificed at 4 and 8 weeks. The implants were removed by reverse torque rotation using a digital torque-measuring device. A total of 40 implants in 20 rabbits were used for the removal torque measurements. Results: In the Group A, 4 weeks after implant placement, the mean removal torque for the HAPTITE and TSV was $70.7{\pm}31.6$ N cm and $28.9{\pm}15.1$ N cm, respectively. Eight weeks after implant placement, the mean removal torque for the HAPTITE and TSV was $87.9{\pm}26.2$ N cm and $54.9{\pm}22.4$ N cm, respectively. In the Group B, 4 weeks after implant placement, the mean removal torque for the HAPTITE and BioTite-H was $58.0{\pm}29.6$ N cm and $37.7{\pm}14.1$ N cm, respectively. Eight weeks after implant placement, the mean removal torque for the HAPTITE and BioTite-H was $91.4{\pm}47.1$ N cm and $30.8{\pm}9.8$ N cm. HAPTITE showed a higher removal torque than the other implants. Conclusion: These results suggest that HAPTITE increases the strength of osseointegration significantly as determined by the resistance to reverse torque rotation.

• 대한물리치료과학회지
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• 제3권2호
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• pp.951-961
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• 1996

Isokinetic exercise is dynamic, but the spped of movement must be regulated so that the resistance is in ratio to the force applied at each point throughout the full range of motion. The purpose of this study is to comparise with trunk flexors & extensors of isokinetic evaluation of pre-exercise and post-exercise in operated laminectomy & disectomy patients. 7 subjects were examined at $120^{\circ}$/sec and $60^{\circ}$/sec each 15 days. The results were as follows; 1. Peak torque of extensors on $60^{\circ}$/sec showed significant difference statistically(p<0.05), but peak torque of flexors on $60^{\circ}$/sec showed no significant difference statistically. 2. Trunk flexors/extensors ratio of peak torque of $60^{\circ}$/sec showed no significant difference ststistically. 3. Peak torque % B.W of extensors on $60^{\circ}$/sec showed significant difference statistically(p<0.05), but peak torque % B.W of flexors on $60^{\circ}$/sec showed no significant difference statistically. 4. TAE of extensors on $60^{\circ}$/sec showed significant difference statistically (p<0.05), but TAE of flexors on $60^{\circ}$/sec showed no significant difference. 5. Total work of flexors & extensors on $60^{\circ}$/sec showed significant difference statistically (p<0.05). 6. Average power of flexors & extensors on $120^{\circ}$/sec showed significant difference statistically(p<0.05). 7. Endurance ratio of flexors & extensors on $120^{\circ}$/sec showed no significant difference statistically. 8. Set total work of flexors & extensors on $120^{\circ}$/sec showed significant difference statistically(p<0.05). 9. TAE of extensors on $120^{\circ}$/sec showed significant difference statistically(p<0.05), TAE of flexors on $120^{\circ}$/sec showed no significant difference statistically. 10. Total work of flexors & extensors on $120^{\circ}$/sec showed significant difference statistically (p<0.05).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.397-399
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• 1999

This paper deals with the torque characteristics of a AFPM motor excited by permanent magnets. According to relative angle difference of two rotor, torque characteristics are studied. According to varied angle of two rotor, torque ripple and, total torque of AFPM motor is different. For minimum torque ripple, angle of two rotor of AFPM motor are investigated. For this study, we used to Maxwell EM 3D program. A prototype AFPM motor have been assembled and driving power supply are made. Characteristics of magnetical and electrical characteristic are investigated.