• Journal of the Korean Geotechnical Society
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• v.22 no.10
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• pp.165-172
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• 2006

This study describes a series of model tests on instrumented pile groups embedded in HAP-CHEN sand undergoing lateral movement. We tried to find the effect of group piles dependent on a number of factors, including the position of the pile in a group, the pile spacing, and the pile arrangement. The results of test are as follows. For the group piles, the bending moment profile for each pile is similar in shape to that of single pile, although the magnitude and the position of the maximum bending moment are different. $R_M$ (the ratio of maximum bending moment) and $R_F$ (the ratio of resistance to lateral soil movement) were found to increase with increasing pile spacing. When a pile is in a group under lateral soil movement, RM increased in the order of the middle row, front row, back row, according to the direction of lateral deformation, and the outer pile has a larger RM than the inner pile.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.50-57
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• 2004

Structural analysis and fatigue tests have been performed to develop design and evaluation technologies of automotive seat frames. Under the back moment loading condition, the numerical simulation unveiled the maximum stress up to the yield strength at the side frame bracket. To measure the stresses under the test condition, strain gauges were attached to some weakest points of the side frames. the measured strains are in good agreements with the CAE results. On the other hand, some fatigue tests have been performed using the side frame bracket specimens made of various welding types to evaluate their durabilities. From the fatigue tests and the numerical analyses, it was recommended that the bracket welding position should be moved upward.

• Korean Journal of Applied Biomechanics
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• v.27 no.3
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• pp.157-164
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• 2017

Objective: The purpose of this study was to investigate kinematic differences in back pike somersault in platform diving according to skill level and to apply the findings to improve performance. Method: Korean divers participating in this study were divided into a skilled group (age: $21.6{\pm}4.16y$, height: $1.68{\pm}0.03m$, weight: $62.0{\pm}3.94kg$, career: $12.6{\pm}5.13y$) and a less-skilled group (age: $20.6{\pm}2.7y$, height: $1.72{\pm}0.05m$, weight: $64.8{\pm}6.76kg$, career: $12.2{\pm}2.49y$) and an independent t-test was performed to analyze differences between groups at the moment of takeoff. Results: The two groups showed significant differences in displacement and velocity of center of mass (COM), takeoff angle, hip joint angle, knee joint angular velocity, and hip joint angular velocity at the takeoff (p<.05), and significant differences in displacement of COM, hip joint, and ankle joint during flight (p<.05). Conclusion: For a successful back pike, the COM should rise quickly in the vertical direction and the hip joint angle and angular velocity should increase. To improve performance, the back pike turn should be practiced on the ground before an attempt on a 10-m platform, to stretch the ankle and knee joints and enable quick flexion of the hip joint when turning in flight.

• The Journal of Korea CHUNA Manual Medicine
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• v.5 no.1
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• pp.93-100
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• 2004

Low back pain(LBP) is known as one of the diseases that produce severe pains with 80% of the whole population having experienced it and reported that, even at this moment, 20-30% of the world population is suffering from it. The writer has performed 'Conservative remedies (non-surgical procedures taken)' from $1^{st}$ of January 2003 to $31^{st}$ of December the same year for 76 cases who have been hospitalized in Jaseng Hospital and adopted as having been diagnosed either HIVD L4-5 or HIVD L5-S 1 or as having both. The clinical analysis was made through statistical researches which include : the changing degree in SLR test of the Cheongpa-Jeon(CP) taking patient group and the non-taking group, the change of VAS (Visual analogue scale) against pains, and the days of hospital treatment. The result demonstrated that the CP taking group showed higher changes in SLR test, bigger reduction In VAS changes and the days for hospitalization shorter than the group that didn't take CP.

• Journal of Korean Academy of Nursing
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• v.28 no.4
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• pp.980-991
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• 1998

The purpose of this study was to examnin the effect of slow stroke back massage(SSBM) on anxiety and immune response in patients undergoing open heart surgery and to compare the effect of 5-minutes with 10-minutes SSBM. Among the sixty-four patient subjects, twenty-one were one experimental group receiving massage for 10-minutes, twenty for the other experimental group receiving massage for 5-minutes and twenty-three for the control group. Subjects were admitted at Hospitals in Inchon and Puchon for open heart surgery. This study was carried out from October 10, 1997 to May 10, 1998. The levels of anxiety were measured by the Visual Analogue Scale(VAS), Trait anxiety scale, systolic and diastolic blood pressure, pulse rate, blood cortisol and the levels of immune response were measured by the blood T-lymphocyte and Natural killer cell. Study measurements were taken before and after SSBM on the 1st post operative day. Data were analyzed using x$^2$ test, oneway ANOVA, paired t-test, t-test and Pearson product moment correlation. The results were summarized as follows : 1. After SSBM, VAS anxiety level, systolic and diastolic blood pressure and pulse rate of the experimental group were decreased significantly than those measurements before the SSBM. After SSBM, significant difference in the VAS anxiety level, systolic blood pressure and pulse rate between the experimental and control groups were found. 2. After SSBM, the blood cortisol of the experimental and control groups were increased significantly compared with before SSBM. But the significant difference in blood cortisol between the two groups was not found. 3. After SSBM, the blood T-lymphocyte percentages of the experimental and control groups were decreased signigicantly and blood Natural killer cell percentages of the two groups were increased compared with before SSBM. But significant difference in blood T-lymphocyte and Natural killer cell percentages between the two groups was not found. 4. Significant difference in VAS anxiety level, systolic and diastolic blood pressure, pulse rate, blood cortisol, blood T-lymphocyte and Natural killer cell percentages between SSBM for 5 minutes and SSBM for 10 minutes were not found. Based upon the results, this study concludes that the slow stroke back massage for 5 minutes is a useful intervention that decreases anxiety and produces relaxation in patients undergoing open heart surgery.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.505-514
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• 2002

In this Paper, we propose a method of content-based image classification using neural network. The images for classification ate object images that can be divided into foreground and background. To deal with the object images efficiently, object region is extracted with a region segmentation technique in the preprocessing step. Features for the classification are texture and shape features extracted from wavelet transformed image. The neural network classifier is constructed with the extracted features and the back-propagation learning algorithm. Among the various texture features, the diagonal moment was more effective. A test with 300 training data and 300 test data composed of 10 images from each of 30 classes shows correct classification rates of 72.3% and 67%, respectively.

• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.7-24
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• 1977

This paper is the forth and fifth one of the study on balanced type oscillating mole drainer. In the light of the results from previous reports about the model tests, some design criteria were established and a prototype machine was set up for experimental purpose. Motion characteristics and functionof the each parts of the machine were checked and analyzed. After that, performance tests of the prototype machine were carried out in thefield. Obtained results are summarized as follows ; 1. Ten centimeter of the bullet diameter was determined so as to be able to attach it to the tractors with capacity of 30 PS to 40 PS. 2. To maintain the balance between the moments of the front shank and rear shank, the oscillating amplitude of the rear bullet was determined to be larger than that of the front bullet. At the same time , the oscillating direction of the rear bullet was designed with the inclines of ten to thirty degrees. 3. An octagonal dynamo transduced was developed for measuring the compressive force of the upper link is measuring the draft force of the machine. Acceptable linear relationship between forces and strain responses from O.D.T. was obtained. 4. Analysing the balancing mechanism of the acting part of the machine , it was found that the total draft force of the machine was equal to the difference between the sum of the draft force produced from the right and left side bending moments of the lower drawber and the compressive force on the upper link. 5. There are acceptable linear relationship between the strain and twisting moment by driving shaft, and between strain and shank moment. Above results enable us to carry out the field experiment with prototype machine. 6. When the test machine was used in the field, it was possible to reduce the oscillating acceleration by forty percent in average as compared it with the single bullet mole drainer. 7. When the test machine was used under the oscillating condition, the dratt torce was reduced by 27 percent to 59 percent as compared it with the test machine under non-oscillating condition, while the draft force was increased by 7 percent to 20 percent as compared it with the mole drainer having oscillating single bullet. The reasoning behind this fact was considered as the resistance force due to the rear shank and bullet. 8. As the amplitude and frequency of the bullet were increased, the torque was increased accordingly. This tendency could be varied with the various characteristics of the given soils. And the larger frequency and amplitute, the more increasing oscil\ulcornerlating power but decreasing draft brce were needed, and draft force was increased as the velocity was increased.9. When the amplitude of the rear bullet was designed to be larger than that of the front bullet, the minimum value of the moment was lowered and oscillating acceleration was reduced. And when the oscillating direction of the rear bullet was declined back\ulcornerwards, oscillating acceleration was increased along with the increasing angle of decli\ulcornernation. When the test machine was operated in high speed, the difference between maximum moments and minimum ones became narrow. This varying magnitude of moments appeared on the moment oscillogram seems to be correlated to the oscillating acceleration and draft force. 10. From the analysis of variance, it was found that those factors such as frequency, amplitude, and operating velocity significantly affected in the oscillating acceleration, the draft resistance, the torque, the moment, and the total power required. And interaction between frequency and amplitude affected in the oscillating acceleration. 11. Within the given situation of this study, the most preferable operating conditions of the test machine were 7 Hz in oscillating frequency, 0.54 m/sec in operating velocity, and 39.1 mm in oscillating amplitude of front and rear bullets. However, it is necessary to select the proper frequency and magnitude of oscillation depending on the soil properties of the field in which the mole drainer is practiced by use of a bal1nced type oscillating mole drainer. 12. It is recommended that a comparative study of the mole drainers would be performed in the near future using two separate balanced oscillating bullet with the one which is operated by oscillating the movable bullet in a single cylinder or other balanced type which may be single oscillating bullet with spring, damper or balancing weight, and that of thing. To expand the applicability of the balanced type oscillating mole drainer in practical use, it is suggested to develop a new mechanism which perform mole drain with vinyl pipe or filling material such as rice hull.

• Korean Security Journal
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• no.31
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• pp.187-207
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• 2012

The purpose of this study was to analyze the punching movement at the horseback riding stance, one of the basic movements in Taekwondo, with 3D images and further the kinetic variables such as time, velocity, angle, angular velocity, and angular acceleration according to the types. It also aimed to examine the characteristics of each type and suggest instructional methods for the right punching movement. For those purposes, three members from the College Taekwondo Poomse Demonstration Squad were put to the test. The research findings led to the following conclusions: 1. Performance Time of the Punching Movement : In Section 1, Type 1 and 2 recorded $0.24{\pm}0.07s$ and $0.42{\pm}0.08s$, respectively, for the punching movement at the horseback riding stance. While Type 1 took less performance time in the punching movement, Type 2 took less time for take back according to each section's percentage in the total performance time. 2. Variables of Linear Velocity and Linear Acceleration : Each type recorded different linear velocity for each aspect, but the highest linear velocity represented the moment of impact for each type. Type 2 recorded the highest linear velocity in Aspect 4, which was the moment of impact. 3. Variable of Joint Angle : There were no big outer differences in the joint angle during the punching movement between Type 1 in the aspect of impact and Type 2, but the individuals assumed dynamic positions in the punching movement of Type 2 with more diverse changes to the joint angle. 4. Variables of Angular Velocity and Angular Acceleration During the punching movement of Type 1, the Aspect 3 in the moment of impact recorded angular velocity of $0.79{\pm}0.02deg/s$, $0.91{\pm}0.04deg/s$, and $5.24{\pm}0.09deg/s$ at the pelvis, shoulder, and wrist respectively. During the punching movement of Type 2, the Aspect 3 in the moment of impact recorded angular velocity of $1.32{\pm}0.03deg/s$, $0.21{\pm}0.03deg/s$, and $4.98{\pm}0.08deg/$ at the shoulder, wrist, and pelvis, respectively. In the Aspect 3 in the moment of impact in Type 2, the angular acceleration at the right wrist joint was $176.24{\pm}1.11deg/s^2$, which was bigger than that in the moment of impact in Type 1.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.3-44
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• 1999

This paper discusses the lateral behavior of single and group piles in homogeneous and non-homogeneous(two layered) soil. In the single pile, the model tests were conducted to investigate the effects on ratio of lower layer height to embedded pile length, ratio of soil modules of upper layer to lower layer, boundary rendition of pile head and tip, embedded pile length, pile construction condition, ground condition with saturate and moisture state in Nak-Dong river sand. Also, in the group pile, the model tests were to investigate the effects on spacing-to-diameter ratio of pile, pile array, ratio of pile spacing, boundary condition of pile head and tip, eccentric load and ground condition. The maximum bending moment and deflection induced in active piles were found to be highly dependent on the relative density, pile construction condition, boundary condition of pile head and tip. Based on the results obtained, it was found that the decrease of lateral bearing capacity in saturated sand was in the range of 31% - 53% as compared with the case of dry sand. Also, in the group pile, a spacing-to-diameter of 6.0 seems to be large enough to eliminate the group effect for the case of relative density of 61.8%, and 32.8%, and then each pile in such a case behaves essentially the same as a single pile. In this study, the program is developed by using the modified Chang method which used p - y method and the exact solution of governing equation of pile and it can be used to calculate the deflection, bending moment and soil reaction with FDM in non-homogeneous soil. In comparing the modified Chang method with field test results, the predict results shows better agreement with measured results in field tests.

• Korean journal of applied entomology
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• v.31 no.2
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• pp.182-189
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• 1992

The influnces of 9 kinds of solvents on the toxicities against several insect species, phytotoxicity and solubility of compounds were evaluated by means of leaf dipping and spray methods. In case of the spray application, density and vapor pressure seemed to be a contributing factor to lethal toxicity against brown planthopper and diamond-back moth, respectively; the bigger the property of density and the smaller the vapor pressure gave the stronger toxicity. It appeared that the toxicity of solvents was not correlated with anyone of physical properties such as boiling point, dipole moment, dielectric constant, surface tension and viscosity. Spray treatment gave more toxicity to insects than leaf dipping treatment. Although dielectric constant and dipole moment seemed to be contributing factors to phytotoxic damage to rice seedling and bean plants, respectively, no general correlation between phytoxicity and the other physical properties was found. Leaf dipping application caused stronger phytotoxicity than spray application. It is concluded that 5% acetone solution may be most suitable to test chemicals because of its favorable solubility of compounds, lower toxicity to insects, and lower phytotoxicity.