• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.137-147
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• 2014

Purpose : The purpose of this study is to verify the accuracy of dose delivery according to the patient's breathing cycle in Gated Volumetric Modulated Arc Therapy Materials and Methods : TrueBeam STxTM(Varian Medical System, Palo Alto, CA) was used in this experiment. The Computed tomography(CT) images that were acquired with RANDO Phantom(Alderson Research Laboratories Inc. Stamford. CT, USA), using Computerized treatment planning system(Eclipse 10.0, Varian, USA), were used to create VMAT plans using 10MV FFF with 1500 cGy/fx (case 1, 2, 3) and 220 cGy/fx(case 4, 5, 6) of doserate of 1200 MU/min. The regular respiratory period of 1.5, 2.5, 3.5 and 4.5 sec and the patients respiratory period of 2.2 and 3.5 sec were reproduced with the $QUASAR^{TM}$ Respiratory Motion Phantom(Modus Medical Devices Inc), and it was set up to deliver radiation at the phase mode between the ranges of 30 to 70%. The results were measured at respective respiratory conditions by a 2-Dimensional ion chamber array detector(I'mRT Matrixx, IBA Dosimetry, Germany) and a MultiCube Phantom(IBA Dosimetry, Germany), and the Gamma pass rate(3 mm, 3%) were compared by the IMRT analysis program(OmniPro I'mRT system software Version 1.7b, IBA Dosimetry, Germany) Results : The gamma pass rates of Case 1, 2, 3, 4, 5 and 6 were the results of 100.0, 97.6, 98.1, 96.3, 93.0, 94.8% at a regular respiratory period of 1.5 sec and 98.8, 99.5, 97.5, 99.5, 98.3, 99.6% at 2.5 sec, 99.6, 96.6, 97.5, 99.2, 97.8, 99.1% at 3.5 sec and 99.4, 96.3, 97.2, 99.0, 98.0, 99.3% at 4.5 sec, respectively. When a patient's respiration was reproduced, 97.7, 95.4, 96.2, 98.9, 96.2, 98.4% at average respiratory period of 2.2 sec, and 97.3, 97.5, 96.8, 100.0, 99.3, 99.8% at 3.5 sec, respectively. Conclusion : The experiment showed clinically reliable results of a Gamma pass rate of 95% or more when 2.5 sec or more of a regular breathing period and the patient's breathing were reproduced. While it showed the results of 93.0% and 94.8% at a regular breathing period of 1.5 sec of Case 5 and 6, it could be confirmed that the accurate dose delivery could be possible on the most respiratory conditions because based on the results of 100 patients's respiratory period analysis as no one sustained a respiration of 1.5 sec. But, pretreatment dose verification should be precede because we can't exclude the possibility of error occurrence due to extremely short respiratory period, also a training at the simulation and careful monitoring are necessary for a patient to maintain stable breathing. Consequently, more reliable and accurate treatments can be administered.

• Science of Emotion and Sensibility
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• v.2 no.2
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• pp.43-52
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• 1999

정서는 생리적 반응을 수반하는 주관적인 경험이다. 뇌파와 자율신경계 반응의 차이에 의한 기본정서 구분 연구는 보고된 바가 없다. 본 연구에서는 1) 여섯 기본정서를 뚜렷하게 유발하는 정서자극을 선정하고, 이를 사용하여 2) 기본정서를 구분할 수 있는 심리생리적 복합 지표 모델을 개발하고자 하였다. 국제정서사진체계에서 여섯 기본정서 (행복, 슬픔, 분노, 혐오, 공포, 놀람) 각각을 신뢰롭게 유발하는 여섯 쌍의 슬라이드를 선택하였다. 슬라이드 제시에 의하여 유발되는 뇌파, 심전도, 호흡, 피부전기반응을 기록하여 분석/비교하였다. 주요결과를 요약하면 다음과 같다. 첫째, 뇌파의 상태적 출현량, 심박률, 호흡률, 피부전도반응은 안정상태와 정서상태간의 비교에서 유의미한 차이가 나타났다. 둘째, 뇌파분석결과에서는 theta (F4, 01), slow alpha (F3, F4), fast alpha (O2), fast beta (F4, O2)파의 상대적 출현량 변화값이 일부 정서들간에 유의미한 차이가 있었다. 셋째, 자율신경계 분석결과에서는 심박률, 호흡률, 피부전도반응이 일부 정서들간에 유의미한 차이를 보여주었다. 이들 결과를 토대로 기본정서를 특정적으로 구분할 수 있는 심리생리적 복합 지표 모델을 구성하였다. 네 기본정서 (공포, 혐오, 슬픔, 분노)는 뇌파와 자율신경계 반응패턴에 의한 구분이 가능하였으나, 행복과 놀람은 본 연구에서 사용한 심리생리지표에 의한 최종 구분이 불가능하였다. 여섯 기본정서를 모두 구분할 수 있는 적절한 지표를 찾아내는 후속연구가 필요하다.

• 한국해양학회지
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• v.21 no.2
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• pp.73-84
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• 1986

Photometric Winkler titration provides high precision enough to use the oxygen method in moderately productive waters In short incubation (2-4hr), about $2{\mu\textrm{g}}C/\ell/h$ can be differentiated by the photometric titration. The oxygen and $^{14}C$ methods resulted in good agreement with each other in the diurnal primary production measurements. Despite small descrepancies the severe underestimation of $^{14}C-technique$ was not observed in short-term incubation. Size-fractionated production studies indicated the importance of nanoplanktonic production in the coastal water (62-88%). Bacterial respiration may lead to significant underestimation in estimating net photosynthesis in the oxygen method. In spite of some problems associated with the ecological application of antibiotics, it seems feasible to use Gentamycin in separating planktonic respiration from that of total community.

• The korean journal of orthodontics
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• v.41 no.3
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• pp.164-173
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• 2011

Objective: The purpose of this study was to perform gender-wise analysis of the related cephalometric factors affecting Korean patients with obstructive sleep apnea (OSA). Methods: We examined 118 adults who had visited the Sleep Disorder Clinic Center in Keimyung university, Daegu, Korea, and evaluated them by using poly-somnography (PSG) and lateral cephalograms. The patients were divided into 4 groups (male simple snorers, male OSA patients, female simple snorers, and female OSA patients) according to AHI (apnea-hypopnea index) and sex. Results: The position of the hyoid bone in the female OSA group was inferior to that in the female simple snorer group. Multiple regression analysis showed that tongue length and soft palate width were significant determinants for the severity of AHI in male OSA patients. However, inferior position of the hyoid was a significant determinant only in women. Conclusions: From a cephalometric point of view, OSA in male and female adult patients may be characterized by different pathogeneses. In particular, in female OSA patients, they might be managed by individualized treatments such as hormone replacement therapy in addition to conventional treatment.

• Journal of Life Science
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• v.20 no.12
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• pp.1867-1871
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• 2010

The purpose of this study was to investigate the effects of 12 weeks of abdominal breathing exercises, through AB spur, on weight and BMI, % body fat, and waist-hip ratio in healthy college students. The subjects consisted of 20 obese young college students, and all of whom had no other health complications. The subjects were shown in detail the proper way to utilize the equipment and practice abdominal breathing in a laboratory setting. They were told to wear the AB spur for at least six hours a day in order to induce abdominal breathing exercise. Because the subjects were students, most of the abdominal breathing exercises took place while they were sitting in lectures at school, and they wore the equipment for 12 weeks. At 4, 8, and 12 weeks after the subjects started using the AB spur, there were significant decreases in weight, % body fat, BMI, and waist-hip ratio (p<0.05). In conclusion, the results of the stud suggest that abdominal breathing exercise may be a good weight loss method, as well as a beneficial way to decrease obesity factors, in obese college students.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.389-394
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• 2014

This study was conducted to find out the soil $CO_2$ emission characteristic due to rain fall pattern and intensity changes. Using Automatic Opening and Closing Chambers (AOCCs), we have measured annual soil respiration changes in Pinus koraiensis plantation at Seoul National University experimental forest in Mt. Taehwa. In addition, we have monitored heterotrophic respiration at trenching sites ($4{\times}6m$). Based on the one year data of soil respiration and heterotrophic respiration, we observed that 24% of soil respiration was derived from root respiration. During the rainy season (end of July to September), soil respiration at trenching site and trenching with rainfall interception site were measure during portable soil respiration analyzer (GMP343, Vaisala, Helsinki, Finland). Surprisingly, even after days of continuous heavy rain, soil water content did not exceed 20%. Based on this observation, we suggest that the maximum water holding capacity is about 20%, and relatively lower soil water contents during the dry season affect the vital degree of trees and soil microbe. As for soil respiration under different rain intensity, it was increased about 14.4% under 10 mm precipitation. But the high-intensity rain condition, such as more than 10 mm precipitation, caused the decrease of soil respiration up to 25.5%. Taken together, this study suggests that the pattern of soil respiration can be regulated by not only soil temperature but also due to the rain fall intensity.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.4
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• pp.285-295
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• 2021

Sleep plays an important role in maintaining overall human health. There is increasing interest regarding the impact of sleep related disorders on metabolic diseases. Obstructive sleep apnea (OSA) is a common health problem, and in the last decade, the emergence of increasing obesity rates has further led to a remarkable increase in the prevalence of OSA, along with more prominent metabolic diseases. Obesity is the strongest risk factor for OSA. However, OSA is also known to cause obesity, suggesting an interaction between OSA and obesity. Although the underlying mechanisms leading to OSA-induced metabolic diseases are probably multi-factorial and are yet to be fully elucidated, the activation of inflammation and oxidative stress and the dysregulation of appetite-regulating hormones have emerged as important pathophysiological components of metabolic dysfunction and obesity observed in patients with OSA. Here, we will review the current state of research regarding the association of OSA with metabolic diseases and the possible pathophysiological mechanisms by which OSA could lead to such diseases. This will enhance our understanding of the potential interactions between OSA and obesity and between OSA and metabolic dysfunction.

• Journal of The Korean Association For Science Education
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• v.29 no.6
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• pp.712-729
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• 2009

This study aims to research high school students' misconception of botanic photosynthesis and respiration, and as the measure of rectifying the misconception, to develop the teaching program based on Driver's conceptual change model, applying it to classes and observing the effect. Selected as the research subject was sixty-six students in 1st year of a highschool located in Busan who had chosen Biology Learning as discretionary subject, with their conceptual level on botanic photosynthesis and respiration researched through tests in drawing and descriptive writing. As a consequence of applying drawing as a way of classifying the levels of students' misconception on photosynthesis and respiration, many students' drawings included their misconception caused by textbooks or scientists, but after application of Driver's conceptual change model, they drew scientific drawings including the fundamental factors of botanic photosynthesis and respiration such as light, carbon dioxide, water, glucose, oxygen, leaf, chloroplast, mitochondria, stoma, and energy. Likewise, as a result of the descriptive writing test implemented for researching the students' conception on the various aspects of botanic photosynthesis and respiration, many students in the pretest showed misconception on the point of time and location at which botanic photosynthesis and respiration occur, botanic nutrient, the role of a leaf in photosynthesis, and the relation between botanic photosynthesis and respiration, but after teaching based on Driver's conceptual change model, their misconceptions on photosynthesis and respiration were rectified to a high degree.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.125-131
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• 2005

Purpose : For stereotactic radiosurgery (SRS) of a tumor in the region whose movement due to respiration is significant, like Lung lower lobe, the gated therapy, which delivers radiation dose to the selected respiratory phases when tumor motion is small, was performed using the Respiratory gating system and its clinical effectiveness was evaluated. Materials and Methods : For two SRS patients with a tumor in Lung lower lobe, a marker block (infrared reflector) was attached on the abdomen. While patient' respiratory cycle was monitored with Real-time Position Management (RPM, Varian, USA), 4D CT was performed (10 phases per a cycle). Phases in which tumor motion did not change rapidly were decided as treatment phases. The treatment volume was contoured on the CT images for selected treatment phases using maximum intensity projection (MIP) method. In order to verify setup reproducibility and positional variation, 4D CT was repeated. Results : Gross tumor volume (GTV) showed maximum movement in superior-inferior direction. For patient #1, motion of GTV was reduced to 2.6 mm in treatment phases ($30{\sim}60%$), while that was 9.4 mm in full phases ($0{\sim}90%$) and for patient #2, it was reduced to 2.3 mm in treatment phases ($30{\sim}70%$), while it was 11.7 mm in full phases ($0{\sim}90%$). When comparing two sets of CT images, setup errors in all the directions were within 3 mm. Conclusion : Since tumor motion was reduced less than 5 mm, the Respiratory gating system for SRS of Lung lower lobe is useful.

• Tuberculosis and Respiratory Diseases
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• v.49 no.6
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• pp.715-723
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• 2000

Background : Obstructive sleep apnea syndrome (OSAS) affects systemic blood pressure and cardiac function. The development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac rhythm, suggests that recurrent hypoxia and arousals from sleep may increase a sympathetic nervous system activity. Continuous positive airway pressure (CPAP) therapy has been found to be an effective treatment of OSAS. However, only a few studies have investigated the cardiovascular and sympathetic effects of CPAP therapy. We evaluated influences of nasal CPAP therapy on the cardiovascular system and the sympathetic activity in patients with OSAS. Methods : Thirteen patients with OSAS underwent CPAP therapy and were monitored using polysomnography, blood pressure, heart rate, presence of arrhythmia and the concentration of plasma catecholamines, before and with CPAP therapy. Results: The apnea-hypopnea index (AHI) was significant1y decreased (p<0.01) and the lowest arterial oxygen saturation level was elevated significantly after applying CPAP (p<0.01). Systolic blood pressure tended to decrease after CPAP but without statistical significance. Heart rates during sleep were not significantly different after CPAP. However, the frequency and number of types of arrhythmia decreased and sinus bradytachyarrhythmia disappeared after CPAP. Although there was no significant difference in the level of plasma epinephrine concentration, plasma norepinephrine concentration significantly decreased after CPAP (p<0.05). Conclusion : CPAP therapy decreased the apnea-hypopnea index, hypoxic episodes and plasma norepinephrine concentration. In addition, it decreased the incidence of arrhythmia and tended to decrease the systemic blood pressure. These results indicate that CPAP may play an important role in the prevention of cardiovascular complications in patients with OSAS.