• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.919-920
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• 2010

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.4
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• pp.686-692
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• 2013

Today, environmental issues have become a matter of worldwide concern. In particular, automobile industries engage in considerable research and investment to develop high-efficiency and ecofriendly cars. Most ecofriendly cars use natural gas or hydrogen gas instead of fossil fuels. In this regard, low-weight and high-pressure vessels have gradually been developed to increase the driving distance of a car. However, most pressure vessels installed in cars develop many defects over time owing to shocks sustained when the car is being driven. Such defects can cause the explosion of the pressure vessel. Therefore it is important to prevent such explosions due to internal defects. The use of shearography for measuring the internal defects of objects afford many advantages. It is a non-contact and non-destructive method, and it is not limited by the object shape. In this study, the internal defect deformation and strain of an aluminum liner that is used in a CNG bus for the fuel storage tank is measured using shearography. It is important to measure the strain and deformation in order to detect defects and repair the pressure vessel. To verify the accuracy of the shearography measurement method, the measurement results of shearography, out-of-plane ESPI, and FEM are compared quantitatively.

• Tuberculosis and Respiratory Diseases
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• v.78 no.2
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• pp.85-91
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• 2015

Background: In sepsis patients, target mean arterial pressures (MAPs) greater than 65 mm Hg are recommended. However, there is no such recommendation for patients receiving mechanical ventilation. We aimed to evaluate the influence of MAP over the first 24 hours after intensive care unit (ICU) admission on the mortality rate at 60 days post-admission in patients showing acute hypoxemic respiratory failure under mechanical ventilation. Methods: This prospective, multicenter study included 22 ICUs and compared the mortality and clinical outcomes in patients showing acute hypoxemic respiratory failure with high (75-90 mm Hg) and low (65-74.9 mm Hg) MAPs over the first 24 hours of admission to the ICU. Results: Of the 844 patients with acute hypoxemic respiratory failure, 338 had a sustained MAP of 65-90 mm Hg over the first 24 hours of admission to the ICU. At 60 days, the mortality rates in the low (26.2%) and high (24.5%) MAP groups were not significantly different. The ICU days, hospital days, and 60-day mortality rate did not differ between the groups. Conclusion: In the first 24 hours of ICU admission, MAP range between 65 and 90 mm Hg in patients with acute hypoxemic respiratory failure under mechanical ventilation may not cause significantly differences in 60-day mortality.

• Sleep Medicine and Psychophysiology
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• v.21 no.2
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• pp.51-60
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• 2014

A 'circadian rhythm' is a self-sustained biological rhythm (cycle) that repeats itself approximately every 24 hours. Circadian rhythms are generated by an internal clock, or pacemaker, and persist even in the absence of environmental time cues, collectively termed 'zeitgebers.' Although organisms generate circadian rhythms internally, they are entrained by environmental stimuli, particularly the light-dark cycle. Measurement of the endogenous melatonin rhythm provides relatively reliable surrogate way of assessing the timing of the internal circadian clock. Also, core body temperature and cortisol can be used as markers of circadian rhythms. The sleep-wake cycle, body temperature, and melatonin rhythm have a stable internal phase relationship in humans and other diurnal species. They play an important role in controlling daily behavioral rhythms including task performance, blood pressure, and synthesis and secretion of several hormones. In this review, we address not only the properties, methods of measurement, and markers of circadian rhythms, but also the physiological and psychological importance of human circadian rhythms.

• Tuberculosis and Respiratory Diseases
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• v.65 no.3
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• pp.222-224
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• 2008

Spontaneous pneumomediastinum is defined as a clinical syndrome that's characterized by the presence of air in the mediastinal space, which is not due to an old previous injury or surgery. The condition is caused by a sustained increase in the intraalveolar and intrabronchial pressure with extravasated air dissecting along the perivascular spaces of the mediastinum. This is an uncommon complication of sports activity. The most common symptom is chest pain. This diagnosis should be considered for younger people who present with pleuritic chest pain or dyspnea and a characteristic crackling feel (known as subcutaneous crepitation) when touching of the skin covering the chest wall or neck, and they look otherwise well with normal vital signs. Usually no treatment is required, but the mediastinal air will be absorbed faster if the patient inspires high concentrations of oxygen. We present here a case of spontaneous pneumomediastinum that occurred during a Taekwondo match, along with a review of the relevant literature.

• PNF and Movement
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• v.18 no.1
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• pp.35-44
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• 2020

Purpose: The purpose of this study was to investigate the effect of the simultaneous abdominal drawing-in maneuver (ADIM) on the muscle activity of the ipsilateral trunk and leg during proprioceptive neuromuscular facilitation (PNF) leg flexion, adduction, and external rotation with knee flexion (D1) patterns. Methods: The participants were 20 healthy adult males and females (18 males and 2 females). The maneuvers were performed by a physical therapist who fully understands the PNF leg patterns (D1) and their application in clinical practice. The participants were trained and allowed to practice for 15 minutes prior to applying ADIM, to ensure adequate learning as evidenced by the pressure biofeedback unit. In this study, we measured the muscle activity of the trunk and leg when the PNF leg pattern (D1) was performed by the physical therapist either sustaining or releasing the ADIM. Muscle activity was measured on the right transverse abdominis muscle (TRA), the external abdominal oblique muscle (EO), the internal abdominal oblique muscle (IO), the erector spinae muscle (ES), the vastus medialis oblique muscle (VMO), the vastus lateralis oblique muscle (VLO), and the tibialis anterior muscle (TA) and compared using the mean values from averaging three repeated measurements. Results: The muscle activity of the transversus abdominis, the external abdominal oblique, the internal abdominal oblique, the vastus medialis oblique, and the vastus lateralis oblique was significantly greater (p < 0.05), and the muscle activity of the erector spinae was significantly less (p < 0.05) during PNF leg pattern (D1) when the ADIM contraction was sustained compared to when it was not. Conclusion: These results suggest that sustaining ADIM during PNF leg pattern (D1) training increases the trunk and leg muscle activity, resulting in more effective training.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.135-146
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• 1993

Background: In acute pulmonary embolism it has been postulated that the constriction of bronchi and pulmonary artery secondary to neurohumoral response plays an important role in cardiopulmonary dysfunction in addition to the mechanical obstruction of pulmonary artery. Serotonin is considered as the most important mediator. Positive end expiratory pressure (PEEP) stimulates $PGI_2$ secretion from the vascular endothelium, but its role in acute pulmonary embolism is still in controversy. Methods: To study the cardiopulmonary effect and therapeutic role of Ketanserin, selective antagonist of 5-HT2 receptor, and PEEP in acute pulmonary embolism experimental acute pulmonary embolism was induced in dogs with autologous blood clot. The experimental animals were divided into 3 groups, that is control group, Ketanserin injection group and PEEP application group. Results: Thirty minutes after embolization, mean pulmonary arterial pressure and pulmonary vascular resistance increased and cardiac output decreased. $PaO_2,\;P\bar{v}O_2$ and oxygen transport decreased and physiological shunt and $PaCO_2$ increased. After injection of Ketanserin, comparing with control group, mean pulmonary arterial pressure, pulmonary vascular resistance and physiological shunt decreased, while cardiac output, $PaO_2$ and oxygen transport increased. All these changes sustained till 4 hours after embolization. After PEEP application pulmonary vascular resistance, $PaO_2$ and $PaCO_2$ increased, while physiological shunt, cardiac output and oxygen transport decreased. After discontinuation of PEEP, mean pulmonary arterial pressure and pulmonary vascular resistance decreased and were lower than control group, while $PaO_2$ and cardiac output increased and higher than control group. $PaCO_2$ decreased but showed no significant difference comparing with control group. Conclusion: It can be concluded that Ketanserin is effective for the treatment of acute pulmonary embolism. With PEEP hemodynamic status deteriorated, but improved better than control group after discontinuation of PEEP. Thus PEEP may be applied carefully for short period in acute pulmonary embolism if the hemodynamic status is tolerable.

• Journal of Preventive Medicine and Public Health
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• v.44 no.3
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• pp.131-139
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• 2011

Objectives: Masked hypertension is associated with metabolic risks and increased risk of cardiovascular disease. The purpose of this study was to identify the frequency of and risk factors of masked hypertension in Korean workers. Methods: The study was conducted among 121 employees at a hotel in Gyeongju, Korea, from December 2008 to February 2009. We measured blood pressure (BP) both in the clinic and using 24-hour ambulatory BP monitors for all subjects. Hypertension was defined independently by both methods, and subjects were classified into four groups: true normotension, masked hypertension, white coat hypertension, and sustained hypertension. Results: The frequency of masked hypertension in our study group was 25.6%. Compared with true normotension, the factors related to masked hypertension were male gender (odds ratio [OR], 10.7; 95% confidence interval [CI], 1.41 to 81.09), aging one year (OR, 0.88; 95% CI, 0.78 to 0.99), clinic BP 120-129 /80-84 mmHg (OR, 8.42; 95% CI, 1.51 to 46.82), clinic BP 130-139 / 85-89 mmHg (OR, 12.14; 95% CI, 1.80 to 81.85), smoking (OR, 5.51; 95% CI, 1.15 to 26.54), and increase of total cholesterol 1 mg / dL (OR, 1.05; 95% CI, 1.02 to 1.08). In males only, these factors were clinic BP 120-129/ 80-84 mmHg (OR, 15.07; 95% CI, 1.55 to 146.19), clinic BP 130-139/ 85-89 mmHg (OR, 17.16; 95% CI, 1.56 to 189.45), smoking (OR, 11.61; 95% CI, 1.52 to 88.62), and increase of total cholesterol 1 mg/dL (OR, 1.05; 95% CI, 1.01 to 1.09). Conclusions: The frequency of masked hypertension was high in our study sample. Detection and management of masked hypertension, a known strong predictor of cardiovascular risk, could improve prognosis for at-risk populations.

• Journal of Energy Engineering
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• v.14 no.2 s.42
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• pp.153-158
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• 2005

In order to investigate the short-term performance of polyethylene electrofusion joints, the mechanical tests and stress analysis have been conducted to the artificially defected weld joints. The defects of lack of fusion with a square-type were fabricated with 10, 20, 30, 40, 50, 60$\%$ size of the width of heat-ing wire zone, respectively. In this defect sires range, both tensile and bending test results showed the dependence of defect size to the electrofusion joints performance, but both sustained pressure and crush test results didn't. The numerical stress analysis results including the soil and internal pressures, tensile and bend-ing stresses clearly showed the dependence of fusion defect size. Based on both mechanical test and stress analysis results, the maximum acceptable defect size in polyethylene electrofusion joints is discussed.

• Journal of architectural history
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• v.8 no.4 s.21
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• pp.95-112
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• 1999

This Study starts from a recognition that the architecture is based on the process demanded by substantial needs as well as pure theoretical logic system. So this study aims at proposing another point of view differentiating process and principle of architecture from pure theoretical logic system in the creative process of the Governor's Palace by analyzing drawings in chronological order. Even though the Governor's Palace had not been built because of discord between authorities of India and Le Corbusier, it is undoubtedly one of the best proposals which contains very concepts and ideas of later Le Corbusier's architectural intentions. In the first design stage, overall conception of the building was carried out in the sketches and drawings till Jan, 1954 and in the second stage, the elaboration of the project was pursued till Mar. 1995. The scheme tends to begin too large and general in character, becoming tighter and more complex under pressure from the client and adjustments required by the design process itself. For example, scale reduction, division and development of internal circulation system and applying his early 'Five Points'. So new solutions are searched by oscillating between compromise modifications and radically different solutions in contracting the first ideas. From all these, it is concluded that the early doctrine (Five Points) are adjusted and extended towards another stage by the use of restricted pilotis, the concept of fenetre en longueur transformed into a sub stricture of facade, sustained concept of le plan libre, les toits jardins extended towards concept of the urban area. And these formal intentions of the Governor's Place has been carried through other contemporary projects like Mill Owner's Association in 1954 and Villa Shodan in 1952.