• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.302-307
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• 2016

The technology of multistage deep drawing has been widely applied in the metal forming industry, in order to reduce both the manufacturing cost and time. A battery can used for mobile phone production is a well-known example of multistage deep drawing. It is very difficult to manufacture a battery can, however, because of its large thickness to height aspect ratio. Furthermore, the production of the final parts may result in assembly failure due to springback after multistage deep drawing. In industry, empirical methods such as over bending, corner setting and ironing have been used to reduce springback. In this study, a bottoming approach using the finite element method is proposed as a practical and scientific method of reducing springback. Bottoming induces compression stress in the deformed blank at the final stroke of the punch and, thus, has the effect of reducing springback. Different cases of the bottoming process are studied using the finite element program, DYNAFORM, to determine the optimal die design. The results of the springback simulation after bottoming were found to be in good agreement with the experimental results. In conclusion, the proposed bottoming method is expected to be widely used as a practical method of reducing springback in industry.

• 재활복지
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• v.22 no.3
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• pp.209-224
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• 2018

The purpose of this study is to provide a basic data about the virtual reality rehabilitation therapy to the occupational therapist in the domestic clinical field by systematically analyzing the types and effects of the rehabilitation therapy using the virtual reality program. Research articles were retrieved from January 2007 to December 2017 using the Research Information Sharing Service (RISS), Google Scholar, and Pubmed database. The main search terms were 'Virtual Reality AND Rehabilitation' and 'Virtual reality AND Effect'. Finally, 10 foreign studies were selected as the subjects of this study. Selected studies were organized using PICO (Patient, Intervention, Comparison, Outcome) format. The results were as follows: The subjects were divided into 4 types, stroke, brain tumor, Parkinson 's disease, and kidney disease. The tools used for arbitration were three IREX (30 %), two X-box Kinect (20 %), two Nintendo Wii (20 %), one [Existing tool + VR] (10 %), one [Mobile application + VR] (10 %). As a result of the intervention, improvement of function was observed in all 10 studies from overseas, and physical function was 24 times (66 %), mental function 6 times (17 %), cognitive function 5 times (14 %), Activity of daily living 1 time (10 %). this study could be used as a basic resource to enhance the professionalism and quality of rehabilitation services and expand the scope by organizing virtual reality-based rehabilitation and its effects.

• The Journal of Korean Philosophical History
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• no.32
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• pp.161-183
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• 2011

Lee Ik(李瀷) had put emphasis on the achievements by self-regulated academic learning through doubts, and at the same time that it was all-embracing. His academic attitude had set an example among the members of Seongho school(星湖學派), and his disciples had strived to emulate his style. The greatness of Seongho(星湖)'s study had been revealed by development of Seongho school(星湖學派) right after his death. He had argued that the six strokes of I-Ching should be read having it divided into inward and outward divine signs. He had stated his view clearly that the divine signs ranging from one stroke to six strokes were not connected, same as Shao yong(邵雍)'s method, but, the three strokes of inward divine sign as well as the three strokes of outward divine signs were independent from each other. Seongho(星湖) also had raised many questions about Shifa(筮法), and Bianyao(變爻) and Zhuzi(朱子)'s Shifa(筮法), or Yixueqimeng("易學啓蒙") "Kaobianzhan("考變占")". In view of the Shifa(筮法), Seongho(星湖) had helped Dasan(茶山) to present 'Shiguafa(蓍卦法)' by proposing different divination rule from Zhuzi(朱子)'s Method of Divination by Shiyi("筮儀"). Seongho(星湖) had not professed something significantly different from Zhuzi(朱子) in his I-xue. His study on I-xue had been accomplished under his goal of achievements by self-regulated academic learning through doubts. "Shiguakao("蓍卦攷")" is also same. I-xue of Seongho(星湖) had made a great contribution to form Dasan(茶山)'s I-xue in the later years.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.447-454
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• 2020

The purpose of this study was to determine the clinical effects of blood flow regulation exercise for improving patients' health care and its usefulness as a rehabilitation model for various diseases by analyzing and examining the existing literature. A literature review of Korean academic journals published over a 10-year period, from 2010 to 2019, was conducted using words such as "blood flow regulation," "blood flow restriction," "low-intensity exercise," and "Kaatsu." Kaatsu is a blood flow regulation exercise developed in 1966 by Dr. Yoshiaki Sato of Japan. It is an efficient and effective exercise method that uses blood flow regulation bands that increase the secretion of growth hormones to develop muscles within a short time, improves blood circulation and metabolism to prevent and improve adult diseases, shortens the rehabilitation period, and improves cardiovascular function. The study participants consisted of 10 patients, of whom four were elderly, four had obesity, one was a stroke patient, and one was a trauma patient. The results of this study show that the blood flow regulation exercise, which is a low-intensity exercise, has the same effect as high-intensity exercise, which supports the evidence that it is a highly efficient exercise method for muscle development and rehabilitation of the elderly, adolescents, and patients with injuries who have difficulty in general exercising. For future studies, further reviews are necessary to verify the effectiveness of the exercise method according to blood flow regulation site and type of disease.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.1
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• pp.17-24
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• 2023

Purpose: In the past, detection of metabolic abnormalities in plasma amino acid (PAA) and urine organic acid (UOA) has been widely used to diagnose clinical mitochondrial diseases, such as mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). In this study, the diagnostic values of PAA and UOA were reviewed, and their effectiveness in the diagnosis of MELAS was examined retrospectively. Methods: Blood and urine samples at the time of diagnosis were collected from all clinically diagnosed MELAS patients (n=31), and PAA and UOA tests were performed. All samples were collected in a fasting state to minimize artifacts in the results. The difference in the ratio of abnormal metabolites of PAA and UOA at initial diagnosis was statistically compared between the MELAS with genetic confirmation (n=19, m.3243A>G mutation) and MELAS without genetic confirmation (n=12) groups. The MELAS without genetic confirmation group was used as control. Results: Comparison of PAA and UOA between the two groups revealed that no abnormal metabolites showed characteristic differences between gene-confirmed MELAS patients with and those without genetic confirmation. Conclusions: Abnormal values of metabolites in PAA or UOA might be useful as a screening test but are not sufficient to diagnose MELAS patients.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.57-65
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• 2023

There are differing opinions among scholars as to whether "chuseo" (ugly writing) should be considered as one of the schools in modern calligraphy. Those who do not recognize "chuseo" argue that it lacks traditional rules for stroke formation and therefore loses its distinctiveness. However, the existence and development of "chuseo" are closely related to the constant exploration and reform of modern calligraphy, as well as the increasing aesthetic awareness and changing aesthetic standards of calligraphers with changing times. As a result, there are now more people who recognize "chuseo" as a legitimate form of calligraphy. Calligraphers who lead the times learn and accumulate experiences by adhering to traditional calligraphic principles. However, there are calligraphers who discard the traditional Confucian concept of "chungyong" (中庸) and display "ugliness" in their works. Ok Heung-hwa and Jeung Sang are two such calligraphers who created their own style by incorporating ancient oracle bone inscriptions as their main focus and folk calligraphy as their bloodline. This paper aims to explore and study the definition and formation process of "chuseo" by analyzing the works of Ok Heung-hwa and Jeung Sang. At the same time, it aims to summarize the characteristics and aesthetic beauty of "chuseo".

• Korean Journal of Radiology
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• v.23 no.10
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• pp.939-948
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• 2022

Objective: Evidence supports the efficacy of coronary computed tomography angiography (CCTA)-based risk scores in cardiovascular risk stratification of patients with suspected coronary artery disease (CAD). We aimed to compare two CCTA-based risk score algorithms, Leiden and Confirm scores, in patients with diabetes mellitus (DM) and suspected CAD. Materials and Methods: This single-center prospective cohort study consecutively included 1241 DM patients (54.1% male, 60.2 ± 10.4 years) referred for CCTA for suspected CAD in 2015-2017. Leiden and Confirm scores were calculated and stratified as < 5 (reference), 5-20, and > 20 for Leiden and < 14.3 (reference), 14.3-19.5, and > 19.5 for Confirm. Major adverse cardiovascular events (MACE) were defined as the composite outcomes of cardiovascular death, nonfatal myocardial infarction (MI), stroke, and unstable angina requiring hospitalization. The Cox model and Kaplan-Meier method were used to evaluate the effect size of the risk scores on MACE. The area under the curve (AUC) at the median follow-up time was also compared between score algorithms. Results: During a median follow-up of 31 months (interquartile range, 27.6-37.3 months), 131 of MACE were recorded, including 17 cardiovascular deaths, 28 nonfatal MIs, 64 unstable anginas requiring hospitalization, and 22 strokes. An incremental incidence of MACE was observed in both Leiden and Confirm scores, with an increase in the scores (log-rank p < 0.001). In the multivariable analysis, compared with Leiden score < 5, the hazard ratios for Leiden scores of 5-20 and > 20 were 2.37 (95% confidence interval [CI]: 1.53-3.69; p < 0.001) and 4.39 (95% CI: 2.40-8.01; p < 0.001), respectively, while the Confirm score did not demonstrate a statistically significant association with the risk of MACE. The Leiden score showed a greater AUC of 0.840 compared to 0.777 for the Confirm score (p < 0.001). Conclusion: CCTA-based risk score algorithms could be used as reliable cardiovascular risk predictors in patients with DM and suspected CAD, among which the Leiden score outperformed the Confirm score in predicting MACE.

• Journal of Chest Surgery
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• v.38 no.10 s.255
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• pp.680-684
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• 2005

Background: With the increasing age of the population, coronary artery bypass grafting in the elderly patients is becoming common. Off-pump coronary artery bypass grafting (OPCAB) has been proven to be less morbidity and to facilitate early recovery. The elderly patients may have benefits by avoiding the adverse effects of the cardiopulmonary bypass. The purpose of this study is to evaluate our results of OPCAB in elderly patients. Material and Method: A retrospective chart review was carried out for 12 patients aged over 80 years who underwent isolated OPCAB from January 2001 and March 2004. Data were collected risk factors for disease, extent of coronary disease, and in-hospital outcomes. Postoperative graft patiency was evaluated in 9 patients by multi-slice computed tomography. Result: Eleven patients had triple vessel disease or left main disease. Four patients were suffered from preoperative CVA, and 4 patients had chronic obstructive pulmonary disease. Two patients had myocardial infarction (MI), among them 1 patient was suffered from pulmonary edema after preoperative MI. There was no perioperative death, perioperative MI, and no ventricular arrhythmia. Also there was no perioperative stroke and renal failure. But there was one deep sternal infection who recovered by treating of muscle flap. Atrial fibrillation was newly developed in 1 patient, but was well controlled by medication. Mean intubation time was $15.9\pm4.4(8\~20hrs)$ hrs and mean ICU stay was $2.9\pm0.8(2\~4 days)$ days. Mean hospital day was $21.6\pm14.3(13\~56 days)$ days. Postoperative mean CK-MS was $11.3\pm14.1\;ng/mL$. Early postoperative graft patency rate was $100\%(24/24)$. Follow-up was completed in all patients. In this time, there was no patients with angina or death. Conclusion: The results of this study suggest that OPCAB reduces morbidity and favors hospital outcomes. Therefore, OPCAB is safe, reasonable and might be preferable operative strategy in elderly patients.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.749-754
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• 2004

Off-pump coronary artery bypass grafting (Off-Pump CABG) has been proven to have less morbidity and to facilitate early recovery. High-risk surgical patients may have benefitted by avoiding the adverse effects of the cardiopulmonary bypass. We compared the effectiveness of Off-Pump CABG with that of coronary artery bypass using cardiopulmonary bypass (On-Pump CABG) in high-risk patients. Material and Method: 682 patients (424 Off-Pump CABG and 258 On-Pump CABG) underwent isolated coronary artery bypass grafting between January 2001 and June 2003. Patients who were considered high risk were selected High risk is defined as the presence of one or more of nine adverse prognostic factors. Data were collected from 492 patients in Off-Pump CABG and 100 in On-Pump CABG for risk factors, extent of coronary disease, and in-hospital outcomes. Result： Off-Pump CABG group and On-Pump CABG group did not show differences in their preoperative risk factors. We used more arterial grafts in Off-Pump CABG group (p < 0.05). Postoperative results showed that operative mortality (0.5% in Off-Pump CABG versus 2.0% in On-Pump CABG), renal failure (2.6% in Off-Pump CABG versus 7.0% in On-Pump CABG), and perioperative myocardial infarction (1.5% in Off-Pump CABG versus 1.0% in On-Pump CABG) did not differ significantly. However, Off-Pump CABG had shorter mean operation time (p<0.05), lower mean CK-MB level (p <0.05), lower rate of usage of inotropics (p < 0.05), shorter mean ventilation time (p <0.05), lower perioperative stroke (0% versus 2.0%), and shorter length of stay (p < 0.05) than On-Pump CABG. On-Pump CABG had more distal grafts (p<0.05) than Off-Pump CABG. Although Off-Pump CABG and On-Pump CABG did not show statistical differences in mortality and morbidity was more frequent in CABG. Conclusion: Off-Pump CABG reduces morbidity and favors hospital outcomes. Therefore, Off-Pump CABG is safe, reasonable and may be a preferable operative strategy for high-risk patients.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.322-327
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• 2004

Coronary artery bypass grafting on the beating heart is no longer a new methods for any cardiac surgeon. We evaluated the application of the off-pump coronary artery bypass procedure relative to safety and efficiency as measured by postoperative complication and operative mortality. Material and Method: We used our retrospective database to compare the patients having off-pump coronary surgery (n=100) with those having on-pump coronary surgery (n=100) between June, 1999 and August, 2002. Patients whom underwent associated valvular or aortic aneurysmal operation were excluded. Result: Neither groups showed any differences in the patient's risk factors and extent of coronary disease. Off-pump CABG group did not have significantly less mean operation time (295$\pm$73 min vs 323$\pm$83 min, p=ns) and mean hospital day (15.34$\pm$6.02 day vs 13.80$\pm$4.95 day, p=ns). However, off-pump CABG group had significantly shorter mean ventilation time (17.3$\pm$11.27 hour vs 24.98$\pm$16.1 hour, p＜0.05). No patients were converted to on-pump CABG in off-pump CABG. Intraoperative hemodynamic instability in off-pump CABG were 6 cases, of whom 2 cases were in lateral wall approach and 4 cases in right coronary anastomosis. Postoperative mortality was 1 case in off-pump CABG and 2 cases in on-pump CABG. Intra-aortic ballon pump (IABP) was applied in 1 case with off-pump CABG and in 2 cases with on-pump CABG. No patients presented postoperative cerebral infarction ＆ stroke in off-pump CABG but 2 patients in on-pump CABG. Postoperative arrhythmia presented in 4 cases with off-pump CABG and in 6 cases with on-pump CABG. Acute renal failure (ARF) was complicated in 3 cases with off-pump CABG and in 2 cases with on-pump CABG. Conclusion: This study documented the immediate safety and efficiency of the off-pump CABG procedure.