• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1774-1779
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• 2014

It is known that muscle strength of human body can alter or deteriorate as aging. In this study, we present an inverse dynamics simulation to investigate the effect of muscle strength on performing the daily activities. A 3D musculoskeletal model developed in this study includes several segments of whole body, long and short muscles, ligaments and disc stiffness. Five daily activities such as standing, flexion, finger tip to floor, standing lift close and lifting flexed were simulated with varying the maximum muscle force capacities (MFC) of each muscle fascicles from 30 to $90N/cm^2$ with an increment of $30N/cm^2$. In the result, no solution can be obtained for finger tip to floor and lifting flexed with $30N/cm^2$. Even though the solution was available for standing lift close activity in case of $30N/cm^2$ capacity, many of muscle fascicles hit the upper bound of muscle strength which means that it is not physiologically possible to perform the acvities in reality. For lifing flexed, even the case of $60N/cm^2$ capaciy, represents the moderate healthy people, was not able to find the solutions, showing that 18 muscles among 258 muscle fascicles reached 100% of muscle capacity. The estimated results imply that people who have low muscle strength such as elders or rehabilitation patients were required higher muscle work to perform and maintain the same daily activities than healthy one.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.848-853
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• 2001

Electrostatic actuation was adopted for ease of fabrication. We proposed a new driving scheme that uses the vector sum of force generated by comb-finger and by parallel plate. The moving and fixed electrodes are arranged to maximize the driving force. In this paper, an electrostatic field analysis is performed by Maxwell analysis tool for micro actuators. From the analysis, a comb-parallel type micro-actuator with 4${\mu}{\textrm}{m}$ width, 6${\mu}{\textrm}{m}$ overlap and 45${\mu}{\textrm}{m}$ height could be designed. In order to compare the new type of actuator with the conventional comb type of actuator, we arranged that both types have the same area and the same number of actuators. To make a high aspect ratio structure, we are developing fabrication process using SU-8 and electro-plating.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.1
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• pp.92-106
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• 1990

Active compliance is often used in the control of robot manipulators for the implementation of complex tasks such as assembly, multi-finger fine motion, legged-vehicle adaptive control,etc. This technique balances the interactive force between the manipulator tip and its working environment with its position and velocity errors to achieve the operation of a damped spring. This paper investigates the effecft of passive compliance on system stability with regard to force feedback implementation for actively compliant motion. Usually it is understood that accurate position control require a stiff system. However, theoretical examination of control experiments on a legged suspension vehicle suggests that, if the control includes discrete-time force feedback, some passive compliance is necessssary at the legs of the vehicle for system stability. This can be an important factor to bl considered in manipulator design and control. A theoretical analysis, numerical simulation, and experimental result, confirming the above conclusion, are introduced in this paper.

• Biomedical Science Letters
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• v.13 no.1
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• pp.1-10
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• 2007

Nebulin, a giant modular protein from muscle, is thought to act as molecular ruler in sarcomere assembly. In skeletal muscle, the C-terminal ${\sim}50 kDa$ region of nebulin extends into the Z-line lattice. The most recent studies implicated highlighting its extensive isoform diversity and exciting reports revealed its expression in cardiac and non-muscle tissues containing brain. Also these novel findings are indicating that nebulin is actually a multifunctional filament system, perhaps playing roles in signal transduction, contractile regulation, and myofibril force generation, as well as other not yet defined functions. However the binding protein of nebulin and function in brain is still unknown. A novel binding partner of nebulin C-terminal region was identified by screening a human brain cDNA library using yeast two-hybrid system. Nebulin C-terminus binding protein 51 (NCBP51) was contained a RING-finger domain and identified a new isoform of RING finger protein 125 (RNF125). The interaction was confirmed using the GST pull-down assay. NCBP51 belongs to a family of the RING finger proteins and its function remains to be identified in brain. The role of nebulin and NCBP51 will be studied by loss-of-function using siRNA technique in brain.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.2
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• pp.48-59
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• 1992

In this paper, the effects of a skirt deformation on the responses of an Air Cushion Vehicle in waves are investigated. The air in the bag and in the plenum chamber is assumed to be compressible and to have a uniform instantaneous pressure distribution in each volume. The free surface deformation is determined in the framework of linear potential theory by replacing the cushion pressure with the pressure patch moving uniformly with an oscillating strength. And the bag-finger skirt is assumed to be deformed due to the pressure disturbance while its surface area remained constant. The restoring force and moment due to the deformation of bag-finger skirt from the equilibrium shape is included in the equations of hearse and pitch motions. The numerical results of motion responses due to various ratios of the bag and cushion pressure or bag-to-finger depth ratios are shown.

• Archives of Plastic Surgery
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• v.34 no.2
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• pp.269-273
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• 2007

Purpose: High-pressure injection(HPI) injury is an injury caused by accidental injection of substances by industrial equipment. HPI injury of the hand is a serious injury that can be potentially devastating. There have been a number of publications on the results of its treatment and its functional outcome of these hands. Unfortunately, the clinical outcomes were unsatisfactory following an initial treatment approach of digital expression of the injection material, elevation, soaks, dressing changes, and antibiotics. Methods: A 43-year-old right handed man sustained a high pressure injection injury to the tip of the left index finger. The injected material was industrial paint thinner. Tissue necrosis was noted at the pulp of the finger. Several debridements and irrigation were required. A pedicled chest flap transfer was performed on the eighteenth day after injury as the dorsal nail complex remained viable. This is a retrospective review of our experience with high-pressure finger injection injury caused by paint. A literature review, retrospective chart and radiologic review were presented. Results: Follow-up length was about 1 year. The injuried hand was left nondominant hand, the index. Patient complaints were cold intolerance, paresthesia, contact pain, and impairment of activities of daily living. Conclusion: The outcome of high-pressure injection injuries of the hand is affected by many factors. The time between injury and operative treatment has been regarded as a key determinant by a number of authors. The nature of the injected material is probably more important. It has been noted by many authors that injuries with paints have a worse outcome than those with oil or grease. This study confirms the fact that high-pressure injection injury caused by paint thinner to the hand is a significant problem. Virtually a patient suffers sequelae of this injury. The injury has significant repercussions for future function and reintegration into the work force.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.117-124
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• 2017

Objective: The purpose of this study was to examine the effect of changes in degrees of freedom of the fingers (i.e., the number of the fingers involved in tasks) on the task performance during force production and releasing task. Method: Eight right-handed young men (age: $29.63{\pm}3.02yr$, height: $1.73{\pm}0.04m$, weight: $70.25{\pm}9.05kg$) participated in this study. The subjects were required to press the transducers with three combinations of fingers, including the index-middle (IM), index-middle-ring (IMR), and index-middle-ring-little (IMRL). During the trials, they were instructed to maintain a steady-state level of both normal and tangential forces within the first 5 sec. After the first 5 sec, the subjects were instructed to release the fingers on the transducers as quickly as possible at a self-selected manner within the next 5 sec, resulting in zero force at the end. Customized MATLAB codes (MathWorks Inc., Natick, MA, USA) were written for data analysis. The following variables were quantified: 1) finger force sharing pattern, 2) root mean square error (RMSE) of force to the target force in three axes at the aiming phase, 3) the time duration of the release phase (release time), and 4) the accuracy and precision indexes of the virtual firing position. Results: The RMSE was decreased with the number of fingers increased in both normal and tangential forces at the steady-state phase. The precision index was smaller (more precise) in the IMR condition than in the IM condition, while no significant difference in the accuracy index was observed between the conditions. In addition, no significant difference in release time was found between the conditions. Conclusion: The study provides evidence that the increased number of fingers resulted in better error compensation at the aiming phase and performed a more constant shooting (i.e., smaller precision index). However, the increased number of fingers did not affect the release time, which may influence the consistency of terminal performance. Thus, the number of fingers led to positive results for the current task.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.317-318
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• 2012

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.596-605
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• 1994

An efficient measurement and evaluation system for hand tool tasks will provide a practical solution to the problem of designing and evaluating manual tool tasks in the workplace. Few studies on the biomechanical analysis of hand postures and tool handling tasks exist because of the lack of appropriate measurement techniques for hand force. A measurement system for the finger forces and joint angles for analysis of manual tool handling tasks was developed in this study. The measurement system consists of a force sensing glove made from twelve Force Sensitive Resistors and an angle-measuring glove (Cyberglove$\^$TM/, Virtual technologies) with eighteen joint angle sensors. A biomechanical model of the hand using the data from the measurement system was also developed. Systems of computerized procedures were implemented integrating the hand posture measurement system, biomechanical analysis system, and the task analysis system for manual tool handling tasks. The measurement system was useful in providing the hand force data needed for an existing task analysis system used in CTD risk evaluation. It is expected that the hand posture measurement developed in this study will provide an, efficient and cost-effective solution to task analysis of manual tool handling tasks. These tasks are becoming increasingly important areas of occupational health and safety of the country.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.04a
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• pp.390-394
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• 1994

In many cases, tasks are unpredictable and therefore not doable by special-purpose or pro-programble robots. So master/slave type robot hands which combine human perceptions with conventional robot hands are required as robot end effector. These also can be applied to hazardous worksites such as outer space, deep sea and nuclear power plant. In this study, master/slave type robot fingers with 3 joints each are designed and constructed. To control force accurately, TDT(tension difference type) torque sensors are constructed and attached toeachjoints of slave finger and new force reflecting control algorithm is suggested. Finally, experimental results show that the new control algorithm can be successfully applied.