• Korean Journal of Applied Biomechanics
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• v.34 no.1
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• pp.25-33
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• 2024

Objective: The purpose of this study was to compare the lower extremity muscle activity and knee joint load according to movement speed conditions during the barbell back squat. Method: Nine males with resistance training experience participated in this study. Participants performed the barbell back squat in three conditions (Standard, Fast, and Slow) differing movement speed. During the barbell back squat, muscle activity of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris long head (BFL), semitendinosus (ST), gluteus maximus (GM), gastrocnemius (GCN), and tibialis anterior (TA) was collected using an 8 channel wireless EMG system. The peak flexion angle of the lower extremity joints and the peak resultant joint force in each direction of the knee joint were calculated using eight motion capture cameras and ground reaction force plates. This study was to used the Friedman test and the Wilcoxon signed rank test, to compare lower extremity muscle activity and peak resultant joint force at knee joint according to movement speed conditions during the barbell back squat, and the statistical significance level was set at .01. Results: In the downward phase of the barbell back squat, the RF and TA showed the higher muscle activity in the fast condition, and in the upward phase, RF, VL, VM, BFL, ST, GM, and TA showed the higher muscle activity in the fast condition. As a results, analyzing of the load on the knee joint, in the downward phase, and in the upward phase, the higher peak compressive force of the knee joint was showed in the fast condition. Conclusion: The barbell back squat with fast movement speed was more effective due to increased muscle activity of lower extremity, but one must be careful of knee joint injuries because the load on the knee joint may increase during the barbell back squat with fast movement speed.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.6
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• pp.283-292
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• 2015

In the moment frame subjected to earthquake loads, beam-column joint is structurally important for ductile behavior of a system. ACI Committee 352 proposed guidelines for designing beam-column joint details. The guidelines, however, need to be updated because of the lack of data regarding several factors that may improve the performance of joints. The purpose of this study is to investigate the seismic performance of reinforced concrete exterior joints with high-strength materials and unbonded tendons. Three specimens with different joint shear demand-to-strength ratios were constructed and tested, where headed bars were used to anchor the beam bars into the joint. All specimens showed satisfactory seismic behavior including moment strength of 1.3 times the nominal moment, ductile performance (ductility factor = at least 2.4), and sufficiently large dissipated energy.

• Journal of The Korea Institute of Healthcare Architecture
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• v.12 no.2
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• pp.59-67
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• 2006

The purpose of this study is to present the research data to improve the quality of triangular ward in general hospital in Korea. Drawing documents analysis were used to examine the condition of ward. This study in focused on patient room and atrium according to connection type of triangular ward, allocation of NS, module and direction of patient room. The results of this study is as follows; Triangular ward has two joint pattern(conner and conner, side and side). Conner and conner joint pattern is good at planning of lighting than side and side joint pattern. Triangular ward can has different module system in each side. Allocation of NS is important factor which is focused on patient relationship or ward control.

• Proceedings of the KWS Conference
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• 1995.10a
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• pp.145-148
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• 1995

To provide better understanding of a solder joint design criteria, mathematical models have been developed to calculate the shape of the solder fillets formed between the pad and lead. The effects of parameters such as solder volume and pad dimensions are described with this model. In this study, a systematic way to determine the design criteria of the SMT from the predicted 3D solder joint profile is proposed. The solder joint profile is calculated using the available 3D FEM code which minimizes the system energy due to the surface tension and gravity. The solder joint profiles of gullwing-type lead such as QFP and SOP are calculated for design parameters, and acceptable ranges are obtained. The result shows that the pad length is the most significant factor compared with the pad width and pad area.

• Journal of Veterinary Clinics
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• v.35 no.5
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• pp.247-249
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• 2018

A 3-year-old black Thoroughbred colt weighing 500 kg was admitted to the Equine Hospital of Korea Racing Authority (KRA) due to the chronic gait abnormality of the hindlimbs. The history revealed that the patient had run and fallen onto the fence of the farm about at the age of 1 year old and the lameness had been worsening insidiously since the accident. The degree of lameness was 2/5 in accordance with the AAEP lameness grading system in both hindlimbs at hand walking and trot. The lameness was exacerbated at lunging clockwise and counterclockwise on both hindlimbs. The definitive diagnosis of the bilateral osteoarthritis of coxofemoral joint was established using radiography under general inhalation anesthesia. The prognosis was considered to be poor with low expectancy for racing and the colt was expelled from the racecourse eventually. The clinicians are required to consider the possibility of osteoarthritis of coxofemoral joint presented with chronic hindlimb lameness although it is rare. This is the first report on the bilateral osteoarthritis coxofemoral joint in Republic of Korea.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.117-120
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• 1996

In this paper, a new approach to acquire the cross-sentional image for automatic solder joint inspection of double-sided PCB using X-ray source is presented. We designed the apparatus with fixed X-ray source to realize the cross-sectional image by tunning object and detector synchronously. The cross-sectional images are captured at several view angle of X-ray source, the geometric image distortions caused by view angle and the shape of image intensifier are compensated. The precision variation of cross-sectional image by the change of view angle was investigated. Also we acquired the cross-sectional image to the solder joint of double-sided PCB and reconstructed the shape of solder joint.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.233-239
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• 2003

Three dimensional joint motion data were obtained using X-ray and precise magnetic sensors. Six metal markers were inserted on the femur and the tibia to set the coordinate system. Two magnetic position sensors were used to record motion data and these positions were transformed into the knee motion. The quadriceps muscle was extended in an automatic manner by an extraction machine. Results of the knee joint motion were the same as the clinical data. The proposed method is found to be reasonable in describing the knee motion so that these motion data can be used to simulate the normal knee joint.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1907-1909
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• 1996

In this paper, ultrsonic detection properties at a premolde joint utilized in a 23kV cables are studied. In a experiment a artificial defect within a joint and a measuring system are builded for generating discharges, gathering data about a detection properties, respectively. The experiment results show that one point detection is not allowed for monitoring a global status of a joint discharges and a detection sensitivity is less than 100pC. And also the attenuation and wave speed at the material of joint insulator are obtained.

• The Journal of Korean Physical Therapy
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• v.12 no.3
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• pp.433-444
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• 2000

The purpose is paper was to discuss current concepts related to anatomic stabilizing structures of the shoulder joint complex and their clinical relevance to shoulder instability. The clinical syndrome of shoulder instability represents a wide spectrum of symtoms and signs which may produce various levels of dysfunctions, from subtle subluxations to gross joint instability. The glenohumeral joint attains functional stability through a delicate and intricate interaction between the passive and active stabilizing structures. The passive constraints include the bony geometry, glenoid labrum, and the glenohumeral joint capsuloligaments structure. Conversely, the active constraints, also referred to as active mechanism, include the shoulder complex musculature, the projprioceptive system, and the musculoligamentous relationship. The interaction of the active and passive mechanism which provide passive and active glenohumeral joint stability will be throughtly discussed in this paper

• Korean Journal of Applied Biomechanics
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• v.27 no.1
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• pp.67-74
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• 2017

Objective: The purpose of this study was to apply a general linear model in statistics to marker position vectors used to study human joint rotational motion in biomechanics. Method: For this purpose, a linear model that represents the effect of the center of hip joint rotation and the rotation of the marker position on the response was formulated. Five male subjects performed hip joint functional motions, and the positions of nine markers attached on the thigh with respect to the pelvic coordinate system were acquired at the same time. With the nine marker positions, the center of hip joint rotation and marker positions on the thigh were estimated as parameters in the general linear model. Results: After examining the fitted model, this model did not fit the data appropriately. Conclusion: A refined model is required to take into account specific characteristics of longitudinal data and other covariates such as soft tissue artefacts.