• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.485-490
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• 2004

Sawtooth mixing device used in a non-premixed burner is evaluated for flame stabilization and NO$_{x}$ reduction. Three mixers with different blade angles are tested. Methane is delivered through the fuel jet and air passes through the co-flow annulus. The flame mode changes (attached flame, lifted flame and extinction) against the fuel flow speed are measured, and the stability diagram is drawn. Moreover, by traversing thermocouple and sampling probe in the flame, the distribution of temperature and NO$_{x}$ mole fraction are measured. With the change in blade angle, flame shape, flame stabilization, the distribution of temperature and NO$_{x}$ mole fraction are changed considerably.rably.

• The Journal of Korean Physical Therapy
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• v.27 no.6
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• pp.419-424
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• 2015

Purpose: This study aimed to evaluate the effects of lumbar stabilization exercise on the abdominal muscle-back muscle ratio in white-collar workers. Methods: Forty white-collar workers without any pain who worked at an information technology (IT) company located in the Gyeonggi province were included in this study. Of these, 20 subjects were randomly allocated to the lumbar stabilization exercise group, whereas the remaining 20 were randomly allocated to the control group. The lumbar stabilization exercise group performed a 40-minute-long exercise once a week for 8 weeks. The strength of the abdominal and back muscles was measured using the CENTAUR 3-D Spatial Rotation Device (BFMC, Germany). Data analysis was conducted using SPSS 18.0 for Windows. The Paired t-test was performed to compare the values measured before and after exercise within each group. The independent sample t-test was performed to analyze the differences between the 2 groups. The statistical significance for all the analyses was set at .05. Results: The strength of the abdominal muscles after the exercise significantly differed between the lumbar stabilization exercise group and the control group (p<0.05). However, the increase in the abdominal muscle-back muscle ratio was significant in only the lumbar stabilization exercise group (p<0.05), but not in the control group (p>0.05). Conclusion: The improvement of the abdominal muscle-back muscle ratio through lumbar stabilization exercise may have positive effects on lumbar stabilization. Moreover, lumbar stabilization exercise is considered beneficial for the prevention of back pain and musculoskeletal diseases.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2043-2045
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• 2002

When the input is small, increase of the input leads to a corresponding increase of output, but when the input reaches a certain level, its further increase does produces little or no increase of the output. When this phenomenon happens, the device is said to be in saturation. Occurence of saturation amounts to reducing the gain of the device as the input signals are increased. An extreme case of saturation is the on-off or relay nonlinearity. On-off nonlinearitics have effects similar to those of saturation nonlinearities. Furthermore they can lead to "chattering" in the physical systems doc to their discontinuous nature. This paper presents stabilization method of saturation nonlinearity system using deadzone describing function etc.. And computer simulation results show that saturation nonlinearity can be eliminated due to deadzone nonlinearity.

• The Journal of Korean Physical Therapy
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• v.26 no.1
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• pp.21-26
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• 2014

Purpose: This study examined the effect of trunk stabilization exercise upon the lumbar stabilization and foot pressure on an unstable surface with back pain. Methods: The subjects of the study were 10 patients who showed the symptom of back pain with excessive lumbar curve. This study was 4 weeks, 30 minutes per session, three times a week for a total of 12 times as a result of exercise radiation imaging device and foot pressure analyzer. Results: The sacrohorizontal angle was statistically significant(p<0.05). Comparison of the difference between static right and left foot pressure ratio analysis was statistically significant(p<0.05). Dynamic right and left foot pressure comparisons for the difference was statistically significant in the analysis (p<0.05). Conclusion: Trunk stabilization exercise and the reduction of the excessive sacrohorizontal angle, and static and dynamic foot pressure imbalance reduced left and right.

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.3
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• pp.39-48
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• 2014

Purpose : The purpose of this study was to identify the effect of lumbar stabilization exercise (LSE) and isometric lumbar strengthening exercise (ILSE) on lumbar strength and lumbar extension range in healthy young adults. Method : Ten healthy young adults (six males and four females) volunteered to carry out the LSE and ILSE program for two weeks. The subjects were randomly allocated to two groups: the LSE group (n=5) and the LSE plus ILSE group (n=5). The LSE consisted of 20 minutes of exercise related to lumbar stabilization, and the ILSE was composed of five minutes of isometric stabilization exercise with a specific device. Each group exercised three times per week for two weeks. Assessment tools were made using the subjects' isometric lumbar strength and lumbar extension range before and after the interventions. Results : Statistical analysis revealed significant differences in isometric lumbar strength and the lumbar extension range between before and after the interventions in each group (p<.05). Also, the lumbar extension range improved significantly in the LSE plus ILSE group compared to the LSE group; however, there was no statistically significant difference in the two groups' isometric lumbar strength (p>.05). Conclusion : The findings suggest that ILSE might be feasible in clinical settings by offering benefits for lumbar function. Future studies will be continued.

• Journal of the Korea Society of Computer and Information
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• v.23 no.9
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• pp.107-112
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• 2018

Smart livestock has been proposed as a solution to increase farmers' income and new recruitment of livestock farmers. In this paper, a standardization Plan of breeding management device and collected information for smart livestock cattle was proposed. l Sophisticatedly, basic information will be established for all six types of livestock breeding management device: military automatic feeder, calf automatic feeder, smart milk cooler, feed bin to be able to measure feed residue, smart scale, and biometric information collection device. The standardization, common use, and stabilization of major livestock management device and collected information were suggested to solve the problems caused by in existing breeding management device.

• Journal of Korean Neurosurgical Society
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• v.58 no.5
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• pp.412-418
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• 2015

Objective : To investigate the effects of posterior implant rigidity on spinal kinematics at adjacent levels by utilizing a cadaveric spine model with simulated physiological loading. Methods : Five human lumbar spinal specimens (L3 to S1) were obtained and checked for abnormalities. The fresh specimens were stripped of muscle tissue, with care taken to preserve the spinal ligaments and facet joints. Pedicle screws were implanted in the L4 and L5 vertebrae of each specimen. Specimens were tested under 0 N and 400 N axial loading. Five different posterior rods of various elastic moduli (intact, rubber, low-density polyethylene, aluminum, and titanium) were tested. Segmental range of motion (ROM), center of rotation (COR) and intervertebral disc pressure were investigated. Results : As the rigidity of the posterior rods increased, both the segmental ROM and disc pressure at L4-5 decreased, while those values increased at adjacent levels. Implant stiffness saturation was evident, as the ROM and disc pressure were only marginally increased beyond an implant stiffness of aluminum. Since the disc pressures of adjacent levels were increased by the axial loading, it was shown that the rigidity of the implants influenced the load sharing between the implant and the spinal column. The segmental CORs at the adjacent disc levels translated anteriorly and inferiorly as rigidity of the device increased. Conclusion : These biomechanical findings indicate that the rigidity of the dynamic stabilization implant and physiological loading play significant roles on spinal kinematics at adjacent disc levels, and will aid in further device development.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.665-670
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• 2005

This paper introduces the propulsion system(Motor Block) stabilization test result for Korean High Speed Railway(HSR). The developed propulsion system using high power semiconductor, IGCT(Integrated Gate Commutated Thyristor) consists of two PWM converter and VVVF inverter. In this paper, overall configuration of propulsion system is briefly described and stabilization tests are made to verify the developed propulsion system. The presented test results shows beatless control method of inverter output current at the 200km/h and performance test of BCH.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.71.4-71
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• 2001

This paper presents swing up and stabilization control of an underactuated two-link robot called the Pendubot. This device is a two-link planar robot with an actuator at the shoulder, but no actuator at the elbow. The controller swings up first link from its open loop stable equilibrium point to the unstable equilibrium point and then, catches the unactuated second link to balance it there. Two control algorithms are used for this task. Proportional Derivative Control technique is used to design the swing up control. The linear model of Pendubot is obtained by linearizing the nonlinear dynamic equations about the desired equilibrium point and LQR technique is used to design a stabilization controller.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.4
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• pp.399-405
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• 2009

The focal plane image stabilization for a satellite camera is one of the an effective method which can increase the satellite camera's image quality by removing the motion disturbance of a focal plane. The objectives of this article are to introduce the concept of the focal plane image stabilization and determine the best driving conditions of the actuator for the response and thrust. Under various driving condition the experiments have been performed to investigate the response and thrust characteristics of the piezoelectric driven stick-slip actuator of the focal plane image stabilizing device. From experiments, the best driving frequency and duty ratio for the magnesium slider are 70 kHz and 27%, respectively.