• Journal of the Microelectronics and Packaging Society
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• v.21 no.3
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• pp.25-29
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• 2014

Plasma organic thin film for PCB surface finish is a potential replacement of the conventional PCB finishes because of environment-friendly process, high corrosion-resistance and long shelf life over 1 year. In this study, solder joint properties of the plasma organic surface finish were estimated and compared with OSP surface finish. The plasma surface finish was deposited by chemical vapor deposition from fluorine-based precursors. The thickness of the plasma organic coating was 20 nm. Sn-3.0Ag-0.5Cu (SAC305) solder was used as solder joint materials. From a salt spray test, the plasma organic coating had higher corrosion resistance than the OSP surface finish. The spreadability of SAC305 on plasma organic coating was higher than that on OSP surface finish. SEM and TEM micrographs showed that the interfacial microstructure of the plasma surface finish sample were similar to that of the OSP sample. Solder joint strength of the plasma finish sample was also similar to that of the OSP finished sample.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.582-585
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• 2015

In the aging society, TKRA is steadily increased because of joint diseases. Artificial joint used in TKRA generates metal artifacts in the MRI. Metal artifact may affect diagnosis. In study, We are going to minimize the effect of metal artifact to improve the value of diagnosis by changing the sequence and the type of artificial joint(Co-Cr, Ni-Ti). 1.5T AVANTO, plastic containers and each of the artificial joint (Normal, Co-Cr, NiTi) were used. After the artificial joints fixed in a paper cup was inserted in a plastic container of cylindrical, Signal intensity was measured. To obtain strong and uniform signal intensity, the plastic container was filled with water. We changed Sequences(T1 TSE, T2 TSE, PD TSE) and obtained an Axial image. After excepting the maximum and minimum values, We calculated the average of SNR, CNR and PSNR. Consequently, The SNR, CNR value of PD TSE are measured higher than these of T1 TSE, T2 TSE and The PSNR of Co-Cr is higher than this of Ni-Ti. The SNR of Co-Cr is similar to the SNR of normal comparing this of Ni-Ti. As a result, Using sequence of PD Tse and Co-Cr alloy is considered to be useful.

• Steel and Composite Structures
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• v.26 no.2
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• pp.227-239
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• 2018

Integral abutment bridges (IABs) have no joint across the length of bridge and are therefore also known as jointless bridges. IABs have many advantages, such as structural integrity, efficiency, and stability. More importantly, IABs have proven to be have both low maintenance and construction costs. However, due to the restraints at both ends of the girder due to the absence of a gap (joint), special design considerations are required. For example, while replacing the deck slabs to extend the service life of the IAB, the buckling strength of the steel girder without a deck slab could be much smaller than the case with deck slab in place. With no deck slab, the addition of thermal expansion in the steel girders generates passive earth pressure from the abutment and if the applied axial force is greater than the buckling strength of the steel girders, buckling failure can occur. In this study, numerical simulations were performed to estimate the buckling strength of typical steel girders in IABs. The effects of girder length, the width of flange and thickness of flange, imperfection due to fabrication and construction errors on the buckling strengths of multiple and single girders in IABs are studied. The effect of girder spacing, span length ratio (for a three span girder) and self-weight effects on the buckling strength are also studied. For estimation of the reaction force of the abutment generated by the passive earth pressure of the soil, BA 42/96 (2003), PennDOT DM4 (2015) and the LTI proposed equations (2009) were used and the results obtained are compared with the buckling strength of the steel girders. Using the selected design equations and the results obtained from the numerical analysis, equations for preventing the buckling failure of steel girders during deck replacement for maintenance are presented.

• Journal of the Korean Society for Advanced Composite Structures
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• v.5 no.2
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• pp.21-26
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• 2014

This paper introduces general concepts of jointless bridges and field construction case of semi-integral bridge with psc girder integrating end-diaphragm. The expansion joints need to satisfy thermal and safety conditions of bridges. General bridges with joints have some problems, which are frequently replacement cycle time from mechanical damage or unstable movement, maintenance cost and more. To solve these problems, Integral Abutment Bridges(IAB) have been applied overseas in the 1930s. In Korea, first IAB was constructed in the early 2000s and precast IAB systems was invented and applied lately. Kyungshin overpass bridge in Incheon is the Semi-IAB constructed, the span length is 2@35=70m and the width is 13.9m. The original plan was to use general joint bridge but design field changed with expectations for advanced economic estimation and maintenance. This changed method of B.I.B bridge construction provided not only workability, construction cost but also safety improvement at the same time.

• Advances in concrete construction
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• v.10 no.5
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• pp.455-462
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• 2020

This study investigated the effect of horizontal casting joints on the mechanical properties and structural behavior of sustainable self-compacting reinforced concrete beams (SCRCB). The experimental research consisted of two stages. The first stage used four types of concrete mixtures which were produced to indicate the effects of cement replaced with cement waste at 0%, 5%, 10%, and 15% by weight of cement content on fresh concrete properties of self-compacting concrete (SCC) such as, passing ability, filling ability, and segregation resistance. In addition, mechanical properties such as compressive, tensile, and flexural strength were also studied. The second stage selected the best mixture from the first stage and studied the effect of horizontal casting joints on the structural behavior of sustainable SCRCBs. The effect of horizontal casting joints on the mechanical properties and structural behavior were at the 25%, 50%, 75%, and 100% of sample height. Load deflection, failure mode, and theoretical analysis were studied. Results indicated that the incorporation of replacement with cement waste by 5% to 10% led to economic and environmental advantages, and the results were acceptable for fresh and mechanical properties. The results indicated that delaying the time for casting the second layer and increasing the cement waste in concrete mixtures had a great effect on the mechanical properties of SCC. The ultimate load capacity of horizontal casting joints reinforced concrete beams slightly decreased compared with the control beam. The maximum deflection of casting joint beams with 75% of samples height is similar with the control beam. The experimental results of reinforced concrete beams were substantially acceptable with the theoretical results. The failure modes obtained the best forced casting joint on the structural behavior at 50% height of casting in the beam.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.627-636
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• 2009

This study aims to provide a scientific basis for the abstract beauty of dance by analyzing the effects of controlling the breath during the walking motion of Korean dance. The objective of the study is to determine the significance of breathing during Korean dance, as it is externally expressed and technologically segmented, let alone the internal beauty of Korean dance. The results of this study show that the position of the body center and ASIS during the walking motion that uses breath was lower than that of the walking motion that does not use the breath. In addition, in each replacement of the knee joint and ankle joint, a narrow angle, in which bending is used a lot, appeared during the walking motion that uses the breath, but not during the walking gesture that does not use the breath. This occurred during the bending motion. In the first peak point, the vertical ground reaction force during the walking motion that uses the breath was higher than that during the walking motion that does not use the breath.

• Journal of muscle and joint health
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• v.7 no.2
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• pp.227-240
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• 2000

The purpose of this article was to identify trend in Arthritis research and to provide ba an approach of Arthritis research. The results of analysis of 69 Arthritis articles public year of between 1970-1999 found that most articles(27.6%, n=19) were published since few(10.1%, n=7) were before 1994. Vast majority of articles(79.8%, n=55) were printed in The Journal of Rheumatology Health, and 79.8%(n=55) of those were quantitative research, 8.7%(n=6) were qualitative research, and 14%(n=1) was methodological research. 29.0%(n=20) of quantitative research were carried in experimental design and over half(50.8%, n=35) in nonexperimental design. Having concerned the types of treatment(or intervention) used in experimental study, the most common treatment was 'exercise' (45.0%, n=9), and other less common were 'self-help education(15.0%, n=3), home care(10.0%, n=2) supportive care(10.0%, n=2), flexibility exercise combined with local heat therapy(5.0%, n=1), relaxation training(5.0%, n=1). Of the types of exercise, aquatic exercise was 30.0%(n=6). The effect of exercise on outcome variable was found to be most strong among the other types of treatment. 18 articles of nonexperimental research were correlational research. From the analysis of correlational research, 29 concepts were identified, and the relationship between depression and other variable were strongly reported. In descriptive studies, most commonly physiological variables were examined in 5 articles(29.5%). Only one study(5.9%) explored patient's perception of the causal factors and those causality. In qualitative researches, two study were carried out by the means of grounded theory. Majority of those subjects were RA patients, and the largest number of sample were 23 and the smallest was 1 In two studies, patient's perceived causality of RA was identified as a research problems, and an experience of ADL, fatigue Phenomenon, an experience of having a total knee replacement with osteoarthritis were each found in one study. Methodological research was carried out to test validity and reliability of the RA Fatigue Scale.

• Journal of muscle and joint health
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• v.25 no.2
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• pp.122-134
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• 2018

Purpose: The purpose of this study was to develop a 12-week structured exercise program (12-week-SEP) and evaluate its effects on pain, physical function and quality of life in patients with total hip arthroplasty (THA). Methods: A nonequivalent control group non-synchronized design was utilized to examine the effects of the 12-week-SEP on patients' outcomes after THA. A total of 46 adult patients (experimental group=25, control group=21) who had THA were recruited for the study. The 12-week-SEP consisted of education, exercise (muscle strengthening and progressive walking), and feedback. Data were analyzed by SPSS/WIN 21.0 using the $x^2$ test and repeated measures ANOVA. Results: The mean age of the participants was 60.9 years and 25 men (54.5%) and 21 women (45.7%) were included in the study. There were significant intervention effects on pain reduction and increased physical function but no effects on quality of life. Conclusion: The 12-week-SEP provided pain relief and enhanced physical function in patients underwent THA. Clinical application of the 12-week-SEP can improve postoperative nursing practices for patients with THA. Future research with larger sample is of necessity to obtain greater generalizability of the empirical evidences of the 12-week-SEP.

• Journal of muscle and joint health
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• v.25 no.2
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• pp.61-74
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• 2018

Purpose: The purpose of this study was to examine the factors affecting changes in Korean Knee Score (KKS) and ranges of motion (ROM) of the knee after the structured exercise programs for the patients with total knee arthroplasty. Methods: This was a retrospective study using electronic medical records from January 2015 to February 2017, and the subject of this study was a total of 124 out of 434 patients underwent total knee replacement operation. They took part in a structured step-by-step exercise program conducted by orthopedic nurses, and then were evaluated for KKS and Knee ROM for 12 weeks after operation. Results: Post-intervention scores increased significantly in the KKS subdomains including pain and symptoms (t=-22.31, p<.001), function (t=-20.68, p<.001), evaluation of floor life (t=-14.18, p<.001), socioemotional function (t=-28.94, p<.001) over time. As for the change in the ROM, knee extension (t=9.23, p<.001) and knee flexion (t=4.04, p<.001) showed a statistically significant changes over time. Conclusion: This study illuminated the factors affecting the changes in pain and symptom, physical function, evaluation of floor life, socioemotional function and range of motion after structured exercise training programs for knee arthritis patients.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.1
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• pp.1-6
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• 2009

The usefulness and accuracy of computer-assisted surgery have been evaluated clinically in many orthopedic fields, such as, joint replacement arthroplasty, cruciate ligament reconstruction, and pedicle screw placemen. Recently several preliminary reports have been issued on the application of navigation to bone tumor surgery. The main advantage of navigation-assisted bone tumor surgery is that it provides highly accurate three-dimensional radiological information for intraoperative guidance. In particular, distances from tumors to resection margins can be precisely determined using intraoperative three-dimensional images. Accordingly, the technique allows preservation of function to be maximized by minimizing unnecessary resection. However, surgeons should recognize that the accuracies of navigation systems in bone tumor surgery have some hidden pitfalls. Here, based on our clinical results, we describe the surgical techniques used and include some cautionary notes.