• Journal of Institute of Control, Robotics and Systems
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• v.6 no.9
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• pp.796-802
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• 2000

A master-slave system for teleoperation is usually used to control the robor's motion on remote place such as abyss, outer space etc.. When the slave robot is a humanoid one, it can make a better performance if the configuration of the master arm is similar to that of the slave arm and of the human. The master arm proposed in this paper has a type to be put on the human arm, that is, the exoskeleton type, and has a combination of serial joint and parallel mechanism imitating the human's arm structure of muscles and bones, so called hybrid mechanism so that it can follow arm's movement effectively. But it is easy to solve the forward kinematis of the parallel structure because relating equations are implicit functions. In order to solve that, the virtual joint angle corresponding to human arm's joint is introduced and a sequential computation step is employed in calculating virtual joint angles and the posture of the end effector. Also validity is checked up through computational simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.12
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• pp.1145-1151
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• 2013

Kinematic modeling is a prerequisite for motion planning and the control of mobile robots. In this paper, we proposed a new method of kinematic modeling for a type of mobile robot based on differential motion transformation. The differential motion implies a small translation and rotation in three-dimensional space in a small time interval. Thus, transformation of the differential motion gives the velocity relationship, i.e., Jacobian between two coordinate frames. Since the theory of the differential motion transformation is well-developed, it is useful for the systematic velocity kinematic modeling of mobile robots. In order to show the validity for application of the differential motion transformation, we obtained velocity kinematic models for a type of exemplar mobile robot including spherical ballbots.

• Physical Therapy Korea
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• v.9 no.4
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• pp.45-52
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• 2002

이 연구의 목적은 수직착지시 성에 따른 슬관절 가동범위의 차이를 알아보는 것이다. 연구 대상자는 20대의 건강한 성인 48명(남자 25명, 여자 23명)이었다. 연구 대상자에게 40 cm 높이에서 한발로 뛰어내리도록 하고, 2차원 동작측정 기구인 CMS-HS를 이용하여 수직착지시 슬관절의 굴곡각도, 최대 슬관절 굴곡각도, 슬관절의 가동 범위, 각속도를 측정한 후, 남 여 두 집단간의 차이를 알아보았다. 이때 사용한 분석방법은 독립적인 두 표본 t-검정이었으며 축차적(stepwise) 다변량회귀분석을 이용하여 체중과 신장을 조절한 상태에서 남여 간에 차이가 있는지를 분석하였다. 그 결과 수직착지시 슬관절의 굴곡각도에서는 유의한 차이를 보이지 않았으나, 최대 슬관절 굴곡각도, 슬관절의 가동 범위, 각속도에는 유의한 차이가 있었다(p<.05). 체중과 신장이 조절된 조건 하에서 여자는 수직착지시 최대 슬관절의 굴곡각도와 슬관절의 가동범위가 남자보다 작았다. 이러한 결과를 통하여 수직착지시 여자가 남자보다 슬관절 손상의 빈도가 높은 이유 중의 하나는 여자가 슬관절을 덜 굴곡시킴으로 인해 바닥의 충격을 더 많이 받기 때문이라는 가능성을 발견하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.12
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• pp.105-112
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• 2020

The increase in the edentulous jaw which occurs in the aged population has led to personal dental health concerns. In the case of dental implant surgery, the duration of a patient's recovery depends on the surgical plan and their physicical ability. A device may be required to assist a physician in controlling vibration reduction of free-hand drilling and prescribing a good treatment plan that is suitable for the patient's condition. In this work, an artificial tooth-root implant assistant manipulator was studied. The structure and the vibration analysis of the dynamic restraint manipulator that is for drilling the alveolar bone in the mandible bone were performed, and the structural stability was analyzed. Further, a virtual prototype of an artificial tooth-root implant assisted manipulator was fabricated and tested. Hence, the state of the Remote Center of Motion (RCM) point and the driving state of the manipulator were confirmed. Furthermore, the drilling experiments were performed by using materials similar to a human jawbone in order to evaluate the performance of the drilling process that is operated using the assistant manipulator.

• The Journal of Korean society of community based occupational therapy
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• v.10 no.1
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• pp.31-38
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• 2020

Objective : The purpose of this study is to investigate the effects of bilateral chewing exercise applied for 6 weeks on occlusion force and masseter muscle thickness in the elderly living in the community. Methods : This study recruited 25 community residents. All participants performed bilateral chewing exercise using equipment developed for the purpose of oral chewing exercise. The chewing exercise was divided into isometric and isotonic type and applied for about 20 minutes a day, five times a week for six weeks. For the evaluation, the masseter muscle thickness and the maximum occlusion force were measured three times at three week intervals using a portable ultrasound instrument and an occlusion force gauge. Results : As a result of the change in masseter muscle thickness, baseline, 3 weeks later, and 6 weeks later referred to 7.51±0.43, 7.63±0.44, and 7.83±0.46, respectively (F=3.819, p<.05). The post hoc test resulted in a significance between baseline and 6 weeks later (p=0.023). Similarly, as a result of the change in occlusion force, baseline, 3 weeks later, and 6 weeks later referred to 265±9.22, 268±9.57, and 271.59±10.16, respectively (F=3.031, p<.05). The post hoc test resulted in a significance between baseline and 6 weeks later (p=0.048). Conclusion : This study confirmed that bilateral chewing exercise was effective for increasing masseter muscle thickness and occlusion force in the elderly. Therefore, bilateral chewing exercise can be applied as a therapeutic exercise method for improving oral function.

• Journal of Korean Elementary Science Education
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• v.43 no.2
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• pp.301-321
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• 2024

This study aims to elucidate the historical origins of the long-term demand for the integration of "science subject classes" and "science-related events" within the context of science education for teachers. During the 1970s, science education in elementary schools faced a dual challenge marked by the tension between implementing the third curriculum, which emphasized fundamental science, and the "Pan-National Scientification Movement," which focused on technology education. The Ministry of Education was compelled to integrate the sudden demands of the Yushin regime into the ongoing third curriculum. As these demands emerged from dual policy directives, activities related to elementary science education were subsequently categorized into formal science subject classes and extracurricular science-related events. Although the movement did not directly alter the curriculum, it instigated modifications in personnel structure, activity spaces, and evaluation systems within schools. The introduction of the Pan-National Scientification Movement in elementary schools resulted in changes including the establishment of a new "science lead teacher system," the creation of a dedicated "science corner," and the implementation of a "science badge system." Although the movement was abruptly introduced, it ostensibly contributed to the advancement of the inquiry-oriented approach promoted by the third curriculum. Paradoxically, this advancement was facilitated by the integration of the consequences of the movement into schools' autonomous, extracurricular activities spearheaded by frontline education offices and schools. Although the movement represented a government-driven policy at a particular juncture in time, the manner in which science education practitioners responded to urgent governmental mandates, while preserving the integrity of the long-established third curriculum framework, involved dividing education activities into subject-specific classes and extracurricular science activities. Examining how science education practitioners in the 1970s proactively addressed these challenges offers valuable insights for the science education community in adapting to the current rapidly evolving educational landscape.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.273-284
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• 2020

This paper proposes a method of designing and controlling delta robots with low-cost DC motors, which are widely used in the automation process. Simulation was performed by interpreting the mechanics and dynamics of the delta robot, and based on this analysis, low-cost DC motor was selected. Experiments were conducted to obtain characteristic values of motors and the current-position cascade control system was designed and implemented. In order to verify the feasibility of the proposed system, the experiment to check that the end-effector of the delta robot follows the target path was progressed. Through the experiment, the limitations of using low-cost motors were overcome by designing compensation algorithms and the performance of the position control was verified.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.418-428
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• 2020

The aim of this study was to investigate the effect of resistance exercise(RE) on beta-amyloid(Aβ) metabolism, neuronal cell death, and cognitive function in the transgenic mice model of Alzheimer's disease(AD). Fourteen transgenic(tg) mice and fourteen non-transgenic(non-tg) mice were divided into four groups: (1)non-tg-control(NTC, n=7) (2)non-tg-RE(NTRE, n=7) (3)tg-control(TC, n=7), and (4)tg-RE(TRE, n=7). The groups with RE were performed to progressive RE on ladder equipment for 8 weeks. The groups with RE were performed to progressive RE on ladder equipment for 8 weeks. After then, the cognitive function was measured by using the water maze test, and Aβ metabolism-related proteins, neuronal cell death, and SIRT1/PGC-1α pathway were also measured. Here, we found escape latency and time were significantly increased in the TC compared to the NTC group, but it was significantly reduced in the TRE group, indicating RE may ameliorate cognitive dysfunction. Next, we found an increased in Aβ protein of TC compared to NTC, but it was significantly reduced in the TRE group following RE. In neuronal cell death, Bcl-2 was also significantly decreased and Bax was significantly increased in the TC compared to the NTC group, but RE can increase Bcl-2 and reduce Bax, which may elevate the ratio of Bcl-2/Bax. We further found a decrease in the level of ADAM10 and RARβ protein was significantly increased whereas increased in ROCK1 and BACE1 expression level was significantly reduced following RE in the TRE compared to the TC group. In addition, the level of SIRT1/PGC-1α proteins was decreased in the TC group compared to NTC group, but, these markers were significantly increased in the TRE group following RE. Therefore, our finding indicated that RE may ameliorate cognitive deficits by reducing Aβ protein and neuronal cell death via regulating SIRT1/PGC-1α, amyloidogenic pathway, and non-amyloidogenic pathway, which may play a role in an effective strategy for AD.

• Korean Journal of Occupational Health Nursing
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• v.3
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• pp.71-85
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• 1993

The objective of this study is to describe the frequency of workplace health promotion activites. For this objective, questionaire was requested to 648 trainees of Korea Industrial Safety Corporation. Respondents' positions were safety manager, health care manager, or representatives of employee. Major findings are as follows: 1) Of responding workplaces, 66.2% supported the activities related to promote employees' health. The support rate was higher of Manufacturing and Tranport than others. And the lager workplaces had the higher support rate. 2) Most frequent activity is exercise program. But the prevalence of smoking cessation, stress management, nutrition education and women health care was very low. Major contents of support were to pay the cost of these activites and to equip the places or the facilities. 3) 24.9% had the non-smoking policy in the workplace. 98.6% equiped the places and facilities for employees. Mean number of facilities across all workplaces was 2.96 and that of exercise circles was 3.60. In conclusion, it was suggested that the stratege was needed to develop the Korean model for workplace health promotion on the basis of exisiting activites.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.253-260
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• 2015

There are many efforts to mechanize the process for underwater port construction due to the severe and adverse working environment. This paper presents an underwater construction robot to level rubbles on the seabed for port construction. The robot is composed of a blade and a multi-functional arm to flatten the rubble mound with respect to the reference level at uneven terrain and to dig and dump the rubbles. This research analyzes the kinematics of the blade and the multi-functional arm including track and swing motions with respect to a world coordinate assigned to a reference depth sensor. This analysis is conducted interfacing with the position and orientation sensors installed at the robot. A hydraulic control system is developed to control a track, a blade and a multi-functional arm for rubble leveling work. The experimental results of rubble leveling work conducted by the robot are presented in land and subsea. The working speed of the robot is eight times faster than that of a human diver, and the working quality is acceptable. The robot is expected to have much higher efficiency in deep water where a human diver is unable to work.