• Journal of Korean Association for Spatial Structures
• /
• v.15 no.3
• /
• pp.85-93
• /
• 2015

This paper presents a foundation pile to steel column connection that can resist large magnitude of moment and that can be easy installed. The developed joint has spherical shape and it is given the name HAT joint to mean Hallow half-sphere steel joint. Four types of HAT joints are developed. Namely, H-type, T-type, P-type and K-type. In this paper I will talk about the performance assessment of T-type(Tube Column) and P-type(Pile Column) of HAT joints with finite element analysis and experiment on a full scale model is presented.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1747-1751
• /
• 2003

The paper shows properties such as vickers hardness, yielding and ultimate stresses for the weld zone of the butt and the lap jointed specimens, and compare maximum loads, stress-strain curves, deformation appearance after guided bending test and fracture appearance for butt and lap jointed specimens. The research in this experiment also shows the weldability of the butt joint specimen is better than that of the lap joint specimen using FSW with $2mm^{t}$ aluminum alloy sheet in milling machine.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.315-320
• /
• 2007

An effective reinforcement method for steel tubular joints having a large chord diameter is the use of internal ring stiffeners. This paper presents the results of a numerical study on the static strength of internally ring-stiffened tubular X- and T-joints subjected to brace axial compression loading. Nonlinear finite element analyses are used to compute the joint strength. The influence of geometrical parameters has been studied and the maximum reinforcement effect of a ring stiffener has been evaluated. A strength ratio is defined. by the ratio of ring-stiffened joint strength to unstiffened joint strength, and an equation for this strength ratio is derived by regression analysis. Design optimization for ring stiffener of tubular joints is carried out using metropolis genetic algorithm.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1998.12a
• /
• pp.537-545
• /
• 1998

This paper is the research about a joint coding system of source and channel coding using VF(Variable-to-fixed length) arithmetic code and BCH code. We propose a VF arithmetic coding method with EDC( Error Detecting Capability) and a joint coding method in that the VF arithmetic coding method with EDC is combined with BCH code. By combining both the VF arithmetic code with EDC and BCH code. the proposed joint coding method corrects a source codeword with t-errors in decoding of BCH code and carries out a improvement of the EDC of a codeword with more than (t＋1)-errors in decoding of the VF arithmetic coding with EDC. We examine the performance of the proposed method in terms of compression ratio and EDC.

• Korean Journal of Child Studies
• /
• v.30 no.5
• /
• pp.155-165
• /
• 2009

This study was conducted to identify relationships between toddler-teacher joint attention and toddlers' vocabularies. Toddlers' vocabularies were assessed by the MacArthur Communicative Development Inventory-Korean (MCDI-K) modified by Kim (2006); joint attention episodes were observed by classification categories for engagement condition (Bakeman & Adamson, 1984). Data were analyzed by means, t-test and Pearson's correlations. Results were that : (1) receptive vocabulary of toddlers was about 1.1 times as high as their expressive vocabulary. (2) Coordinated joint attention was observed most frequently, followed by supported joint attention; coordinated joint attention was closely related to support joint attention. (3) The relationship between toddler-teacher joint attention and toddlers' vocabularies were significant in a positive direction.

• Structural Engineering and Mechanics
• /
• v.82 no.6
• /
• pp.801-812
• /
• 2022

To better promote the development of fabricated buildings, this paper studies the seismic behavior of precast concrete beam-column bolted joint under vertical low cyclic loading. The experimental results show that cracks appear in the beam-column joint core area. Meanwhile, the concrete and the grade 5.6 bolts are damaged and deformed, respectively. Specifically, the overall structure of the beam-column joint remains intact, and the bolts have good energy dissipation capacity. Based on the experimental study, a new method of beam-column bolted connection is proposed in simulation analysis. The simulation results show that the bolts deform in the core area of the new beam-column joint, which enhances the concrete shear capacity legitimately and protects the T-end of the beam against shear failure. To summarize, both the experimental joint and the simulated joint prolong the service life by replacing the bolts under the seismic loading. The research results provide a reference for applications of the fabricated beam-column joint.

• Journal of the Chungcheong Mathematical Society
• /
• v.21 no.2
• /
• pp.287-292
• /
• 2008

We introduce jointly weak subnormal operators. It is shown that if $T=(T_1,T_2)$ is subnormal then T is weakly subnormal and if f $T=(T_1,T_2)$ is weakly subnormal then T is hyponormal. We discuss the flatness of weak subnormal operators.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.10
• /
• pp.1078-1088
• /
• 2012

In this paper, we present research experimental results about the different thickness T-joint welding of the high power continuous wave(CW) Nd:YAG laser for the secondary battery of a vehicle. Although the conventional method used for the secondary battery is a argon TIG welding, we utilize a laser welding to improve Tungsten Inert Gas(TIG) welding's weakness. The laser, which has a couple of advantage such as aspect ratio, low Heat Affected Zone(HAZ), good welding quality and fast productivity utilized in this work is a CW Nd:YAG laser. In order to observe laser welding sections, we used a optical microscope. Through the analysis of the metallographic, hardness, aspect ratio, and heat input, we obtained the desired data in condition of 1800 W laser beam power and 1.8 m/min and 2.0 m/min laser beam travel speeds. In order to compare electric resistances of the argon TIG welding and laser welding, we made an actual battery and the electric resistance of the laser welding is reduced by 40~45% comparing with the argon TIG welding.

• Journal of muscle and joint health
• /
• v.31 no.1
• /
• pp.1-11
• /
• 2024

Purpose: This study aimed to evaluate the effects of an arthritis self-management program on elderly women living alone in the community. Methods: This study recruited 36 individuals, who participated in the program once a week for six weeks at two community centers. The program consisted of muscle strengthening and flexibility exercises, health education on muscles and joints, and joint dance for aerobic exercise. The data collected were analyzed using the paired t-test and Wilcoxon rank test. Results: After six weeks, participants showed significant improvements in pain (t=3.03, p=.005), difficulties in activities of daily living (t=2.77, p=.010), health-related quality of life (t=-2.63, p=.014), flexibility of right shoulder (z=-2.42, p=.015), and balance (right leg, t=-2.63, p=.036; left leg, z=-2.36, p=.018). Conclusion: The results showed that the arthritis self-management program effectively improved outcomes for elderly women living alone. Thus, this program could be incorporated into various programs for elderly people living alone.

• Journal of muscle and joint health
• /
• v.3 no.1
• /
• pp.37-49
• /
• 1996

The joint diseases threaten modern people's healthy life. They bring about a long pain, an anasarca, loss of joint function or even deformation and rigidity of joint, limiting people's ordinary activities much. The chronic joint patients may be subject to some hypochondria caused by anxiety for their life, social isolation, financial problem and physical disability. Therefore, this population should continue to be duely taken care of by medical personnels. In particular, nurses should adequately help these people to recover and improve their health through suitable adaptations. With such basic conceptions in mind, this study was aimed at reviewing these patients' conditions in their ordinary life before and after a plastic operation for artificial joint replacement as well as their satisfaction with their life. For this purpose, those patients who underwent some plastic operations for artificial joint replacement at university hospitals in Seoul from January 2, 1993 to June 30, 1995 were selected as the population of this study. Among them, 87 people were randomly sampled to answer a questionnaire designed specially. For the surveying tools, Jette's (1980) scale was applied to address the sample people's inconveniences experienced and supports received in their ordinary life, while the scale of Wood, Wylie & Sheafer was used to measure their satisfaction with their life. The collected data were analyzed for percentiles, means, SD, t-test and Pearson's correlations. The results of survey can be summarized as follows ; As a result of t-test the frequencies of other people's support before and after the plastic operation, it was disclosed that those who underwent the operation were supported less frequently. In addition, as a result of t-testing their satisfaction with life before and after the operation, it was found that the operation increased their satisfaction with life significantly. Meanwhile, as a result of t-test inconveniences, frequencies of supports and life satisfaction before and after the plastic operation for artificial knee replacement, it was disclosed that only the inconveniences were significantly reduced after the operation. In contrast, the t-test the variables before and after the plastic operation for artificial hip replacement, it was found that only the frequencies of other people's supports were significant reduced after the operation. Furthermore, the differences 6 months, one year and two years after the plastic operation for artificial joint replacement were t-tested on the variables. As a result, it was disclosed that people's inconvenience, frequencies of supports and life satisfaction were not improved 6 months after the operation but their frequencies of supports decreased significantly one year after, while their inconveniences and life satisfaction were significantly improved two years after. As a result of analyzing the variables with Pearson's correlations, inconveniences and frequency of supports were negatively correlated significantly with the life satisfaction. In conclusion, the plastic operation for artificial joint replacement significantly improved people's living inconveniences, reduced their frequency of other people's support and enhanced their satisfaction with life. To break don the plastic operation for artificial knee replacement improved patients' inconveniences, while the plastic operation for artificial hip replacement not only improved patients' inconveniences but reduced the frequencies of other people's support also. Finally, the finding that the plastic operation for artificial joint replacement brought about the improvement two years after suggests that this period is needed for the patients to adapt themselves to the post-operation conditions.