• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.35-46
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• 2022

Recently, with the development of network technologies, as IoT and social network service applications have been actively used, a lot of graph stream data is being generated. In this paper, we propose a graph compression scheme that considers the stream graph environment by applying graph mining to the existing compression technique, which has been focused on compression rate and runtime. In this paper, we proposed Incremental frequent pattern based compression technique for graph streams. Since the proposed scheme keeps only the latest reference patterns, it increases the storage utilization and improves the query processing time. In order to show the superiority of the proposed scheme, various performance evaluations are performed in terms of compression rate and processing time compared to the existing method. The proposed scheme is faster than existing similar scheme when the number of duplicated data is large.

• Transactions of Materials Processing
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• v.14 no.7 s.79
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• pp.635-641
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• 2005

The crystal structure of magnesium was hexagonal close-packed (HCP), so its formability was poor at room temperature. But formability was improved in high temperature with increasing of the slip planes. Purpose of this paper was to know about the mechanical properties of magnesium alloy (AZ31B), before warm and hot forming process. The mechanical properties were defined by the tension and compression tests in various temperature and strain-rate. As the temperature was increased, yield·ultimate strength, K-value, work hardening exponent (n) and anisotropy factor (R) were decreased. But strain rate sensitivity (m) was increased. As strain-rate increased, yield·ultimate strength, K-value, and work hardening exponent (n) were increased. Also, microstructures of grains fined away at high strain-rate. These results would be used in simulations and manufacturing factor fer warm and hot forming process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.69-72
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• 2005

The crystal structure of magnesium is hexagonal close-packed (HCP), so its formability is poor at room temperature. But formability is improved in high temperature with increasing of the slip planes. Purpose of this paper is to know about the mechanical properties of magnesium alloy (AZ31B), before warm and hot forming process. The mechanical properties were defined by the tension and compression tests in various temperature and strain-rate. As the temperature is increased, yield${\cdot}$ultimate strength, K-value, work hardening exponent (n) and anisotropy factor (R) are decreased. But strain rate sensitivity (m) is increased. As strain-rate increased, yield${\cdot}$ultimate strength, K-value, and work hardening exponent (n) are increased. Also, microstructures of grains fine away at high strain-rate. These results will be used in simulations and manufacturing factor for warm and hot forming process.

• Journal of the Korean Society of School Health
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• v.27 no.3
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• pp.130-139
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• 2014

Purpose: The object of this study was to compare the educational effect about self-efficacy and the quality of chest compressions of Hands-only CPR and Basic CPR. Methods: It's a nonequivalent control group pre-post repeated quasi-experiment study conducted with entire fifth grade students belong to one school in H city. The study participants are 68 persons, and data were collected from December 2, 2013 to February 7, 2014. Self-efficacy was measured by 10 items, and the quality of chest compressions was measured by 5 variables which are average compression depth(mm), average rate (n/min), average count per minutes (n), abnormal placement (n), compression accuracy (%). Results: Self-efficacy of the experimental group and control group showed no significant difference but showed significant difference over time and was the highest at posttest 1 (immediately after education), the lowest at pretest (before education), middle at posttest 2 (8weeks after education) (p<.001). Experimental group was significantly higher than control group in average rate per minute. At posttest 1, experimental group was $130.0{\pm}9.38$ times, control group was $95.1{\pm}11.82$ times. At posttest2, experimental group was $124.0{\pm}14.89$ times, control group was $90.8{\pm}14.89$ times.(p<.001). Average rate (n/min) was significantly declined at control group in the quality of chest compressions over time (t=-2.400, p=.022). Average count per minute and compression accuracy were declined significantly so it were not maintained to posttest2. Conclusion: We need continuous CPR education because self-efficacy of CPR getting lower significantly over time. Hands-only CPR can't be seen as a way to increase the CPR ability of elementary school students having difficulty to perform artificial breathing. And, because the effect of education is not maintained 8wks after training, the technique centered repeated training is needed and a method which can increase compression accuracy is also needed.

• The Korean Journal of Emergency Medical Services
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• v.7 no.1
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• pp.43-54
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• 2003

The purpose of this study was to evaluate the accuracy of CPR skills and the satisfaction of CPR Training targeted for college students. Also, this study made comparative study of nursing students and non-nursing students. The sample consisted of 248 students(132 nursing students, 116 non-nursing students). CPR Training was designed by two components which were a lecture and demonstration by one professor and individual practice by instructors. As tool of measurement estimation satisfaction of CPR Training questionnaires were developed based on educated contents. The accuracy of CPR skills were checked by SkillReporter CPR training manikin. Collected data were computerized and analyzed by SPSS-WIN program. The results were as follows : 1. The skills of CPR were cardiac compression 92.79 times/min, correct cardiac compression rate 90.85%, ventilation 9.93 times/min, correct ventilation rate 79.34%. 2. The mean of the accuracy of CPR skills were 2.94(SD .87). 3. When errors were analyzed, the highest item was stomach distension(51.2%) of ventilation skills and too little(70.6%) of cardiac compression skills. 4. The mean of the satisfaction of CPR training were 2.87(SD .17), the highest item of the satisfaction of CPR Training was practice. 5. We found significant statistical differences based on the accuracy and the error, non-nursing students were high in correct cardiac compression per minute(t=3.615, p=.000) and ventilation too much(t=4.292, p=.000), nursing students were high in correct ventilation rate(t=-3.885, p=.000) and cardiac compression too shallow) t=-2.842, p=.005).

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.52-58
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• 2005

Purpose: To analyze the overall clinical outcome, overall assessment, and patient's satisfaction rate of subtalar arthrodesis using the cannulated compression screw. Materials and Methods: This study is based on 17 patients, 17 feet who underwent subtalar arthrodesis using the cannulated compression screw from March, 1997 to March, 2004 with at least 1 year follow-up. The average follow-up period was 33.0 months (12 to 72 months). Functional results were assessed using the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot (AOFAS) score, and Visual Analysis Scale (VAS) pain score, patients' returning to previous occupation and patients' satisfaction rate were also evaluated. Results: The mean AOFAS scores at final follow-up were 80.4 points (range $66{\sim}92$). The satisfactory rates were as follow. Thirteen patients (76.4%) were at least satisfied with surgical result at final follow-up. Patients' VAS pain score was average 2.8 points ($1{\sim}6$). Fourteen (82.3%) patients returned to previous job at mean postoperative period of 11.3 months (range 3-18 months). Patients' work efficiency after returning to previous occupation was 68.7% (range $33{\sim}100%$). There were 9 complications which were 3 cases of sural nerve injury, 1 case of valgus malunion, and 5 cases of the hindfoot residual pain. Conclusion: We obtained the satisfactory functional results with relatively high patient satisfaction rate of 76%. So we conclude that subtalar arthrodesis using the cannulated compression screw is a reliable method for addressing the painful end-stage subtalar osteoarthritis and unreconstructible comminuted calcaneal fractures. However we also found out that average 11 months were necessary for patients to return to their job.

• Journal of Biosystems Engineering
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• v.16 no.1
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• pp.37-48
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• 1991

Rice plants are subjected to various forces such as natural force of wind and mechanical force of cultivating machines. Rheological behavior of the rice stem can be expressed in terms of three variables : stress, relaxation and time. The objectives of this study are to examine stress relaxation, creep and recovery characteristics on the rice stem in case of axial and radial loading. Stress relaxation with time was studied on three levels of loading rate and on four levels of applied stress. The results were summarized as follows : 1. The hysterisis losses of the rice stem distinctly observed at the radial compression in comparison with axial compression. The hysterisis loss implied that the stem to absorbed energy without being deformed beyond the yield point. 2. Ageneralized Maxwell model consisting of three elements gave a good description of the relaxation behavior of the rice stem. Rate of loading was more significant on the observed relaxation behavior within the short relaxation time, but there were little influences of rate of loading on the relaxation time. 3. The stress relaxation intensity and the residual stress increased in magnitude as the applied stress increased, but the relaxation time was little affected by the applied stress. 4. The coefficients of the stress relaxation model showed much differences in the radial compression and the axial compression, especially the higher relaxation stress of the third element was observed in the radial compression. 5. The behaviors of rice stem in creep and recovery test also might be represented by a four element Burger's model. But the coefficients of the creep model were different from those of the recovery model. 6. The steady-state phenomena of creep appeared at the stress larger than 20 MPa in Samkang and 1.8 MPa in Whajin. 7. The elastic modulus of the stem showed the range from 40 to 60 MPa. It could be considered, as a result, the rice stems had viscoelastic properties.

• Journal of the Korean Institute of Gas
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• v.16 no.3
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• pp.42-47
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• 2012

In this paper, alternative natural refrigerant R290(Propane), R600(Butane), R717(Ammonia), R1270(Propylene) for freon refrigerant R22 were used working fluids for 2-stage compression and 1-stage expansion refrigeration system. The operating parameters considered in this study included evaporation temperature, condensation temperature, subcooling degree, superheating degree, mass flow rate ratio of inter-cooler. The main results were summarized as follows : The COP of 2-stage compression and 1-stage expansion refrigeration system increases with the increasing subcooling degree and mass flow rate ration of inter-cooler, but decreases with the increasing evaporating temperature, condensing temperature and superheating degree. Therefore, subcooling degree, mass flow rate ratio of inter-cooler of 2-stage compression and 1-stage expansion refrigeration system using natural refrigerants have an effect on COP of this system. The COP of natural refrigerants was higher than the COP of freon R22 in this study, so points to be considered are the security, the attached facilities for natural refrigerants than COP.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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• pp.407-416
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• 2008

Purpose: The aim of the present study is to evaluate the effect of repetitive distraction and compression on new bone formation during distraction period. Materials and methods: Sixteen healthy rabbits, weighing about 2.5kg, were used in this experiment. A unilateral mandibular osteotomy was performed in the left mandible and the distractor(Track 1 $plus^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany) was fixed with four screws (Cross driver screw $TI^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany). After 4 days, the mandibles were distracted at a rate of 0.6mm/day for 10 days to obtain the amount of 6mm distraction in the control group(n=4). In the experimental group A(n=6), they were distracted at a rate of 1.2mm/day for 5 days and then compression of 0.6mm length and distraction of 0.6mm per 12 hours were carried out as counter direction for 5 days, relatively. In the experimental group B(n=6), distraction of 1.2mm length and compression of 0.6mm length per 12 hours were repeated for 10 days to obtain the amount of 6mm distraction finally. The experimental animals were sacrificed at 2 and 4 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E and Masson- Trichrome staining and then, measured Bone Deposition Rate with TOMORO $ScopeEye^{TM}$ ver. 3.5(Olympus, Japan), Results: Histologically, new bone formation was examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. On the histomorphometric analysis, Bone Deposition Rate was higher in the experimental group A$(50.67{\pm}4.36%)$ than in the control group$(45.94{\pm}3.97%)$ and in the experimental group B$(42.68{\pm}5.70%)$. These data showed significant differences statistically(p<0.05). Conclusion: These results show that the distraction osteogenesis using repetitive compression and distraction force in the early consolidation period may be effective for new bone formation.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.420-432
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• 2017

This study examined user needs for compression pant development for women with pes planus in their 50s and 60s. A total of 355 women aged 50 to 69 participated in the survey and interview. Questions were asked if they had pes planus, the using condition of foot orthotic, inconveniences during gait, and wearing condition of compression pants. The results showed that 42 (11.8%) women had pes planus. Orthotic insole and arch support were used most frequently. The most uncomfortable aspect of foot orthotic (n=146) was that it was difficult to use unless they were going outside. Participants with pes planus responded that they felt discomfort on the inner area of propodium, metatarsus, ankle, and knee during gait. The purchase and wearing rate of compression pants were not high; however, compression pants were purchased with specific needs and purposes. Respondents mainly wore the compression pants for sports activities. M size was the most frequently worn size. They preferred high waist type leggings and there was a need to increase the compression strength of the waist, thigh, knee and ankle. Additionally, the ease of donning and doffing were discussed.