• 대한의용생체공학회:의공학회지
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• 제31권2호
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• pp.94-98
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• 2010

In magnetic resonance electrical impedance tomography (MREIT), a current-injection MR imaging method is adopted to produce a cross-sectional image of an electrical conductivity distribution in addition to MR images. The purpose of this study was to test the feasibility of MREIT for differentiating the canine lung parenchyma without and with pneumonia. Three normal healthy beagles and two mixed breed dogs with pneumonia were used. After attaching electrodes around the chest, we placed the dog inside our MR scanner. We injected as much as 30 mA current in a form of short pulses into the chest region. Reconstructed conductivity images of normal canine lungs exhibit a peculiar pattern of a relatively coarse salt and pepper noise. On the contrary, conductivity images of pneumonic canine lungs show significantly enhanced contrast of the lesions while the corresponding MR images show a little bit of contrast in the middle and caudal lung parenchyma due to the accumulation of pleural fluid. This preliminary study indicates that MREIT imaging of the chest may deliver unique new diagnostic information.

• 한국환경과학회지
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• 제18권7호
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• pp.755-765
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• 2009

Some sections of the exhaust system to determine the shape of the duct is to suffer the difficulties by space constraints to install new equipment of the environment post-treatment for existing operation of the power plants. In this paper the large duct in flue gas desulfurization equipments of the 500MW coal-fired power plant on the current operation is numerically analyzed from induced draft fan exit to booster up fan inlet section which is in the narrow space of the exhaust system with four times bending and is connected to emergency duct to bypass the exhaust gas on the emergency operation. The procedure and method using computational fluid dynamics are proposed to maintain the stability of the guide vane with the uniform flow and a minimum pressure loss of exhaust gas in the case of normal and emergency operation between the direction of the flow of exhaust gas duct at different.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.453-463
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• 2013

The probabilistic nature of renewable energy, especially wind energy, increases the needs for new forms of planning and operating with electrical power. This paper presents a novel approach for determining the short-term generation schedule for optimal operations of wind energy-integrated power systems. The proposed probabilistic security-constrained optimal power flow (P-SCOPF) considers dispatch, network, and security constraints in pre- and post-contingency states. The method considers two sources of uncertainty: power demand and wind speed. The power demand is assumed to follow a normal distribution, while the correlated wind speed is modeled by the Weibull distribution. A Monte Carlo simulation is used to choose input variables of power demand and wind speed from their probability distribution functions. Then, P-SCOPF can be applied to the input variables. This approach was tested on a modified IEEE 30-bus system with two wind farms. The results show that the proposed approach provides information on power system economics, security, and environmental parameters to enable better decision-making by system operators.

• 대한통합의학회지
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• 제4권4호
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• pp.77-82
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• 2016

Purpose: The purpose of this study was to investigate the therapeutic effect of non-invasive vagus nerve stimulation by transcutaneous electrical nerve stimulation application on the autonomic nervous system of human body. Methods: Participants were seventeen healthy adults. Standard deviation of all normal N-N intervals(SDNN), root mean square of successive differences(RMSSD), low frequency(LF), high frequency(HF) were compared in pre and post Mean values after intervention. Data were analyzed in Wilcoxon's signed-ranks test. Results: The results of this study is that sistolic blood pressure and pulse rate decreased mean value after non-invasive vagus nerve stimulation by transcutaneous electrical nerve stimulation. High frequency, low frequency, SDNN, RMSSD increased mean value in heart rate variability after intervention. But that is not significant except for SDNN. Conclusion: Non-invasive vagus stimulation by transcutaneous electrical nerve stimulation effect on parasympathetic nerve stimulation, and then it might be effective method for autonomic nerve balance control.

• 대한후두음성언어의학회지
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• 제32권1호
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• pp.1-8
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• 2021

Human vocal cords vibrate as quickly as 100-250 times per second, so it is impossible to observe them with normal endoscopic diagnostic equipment. High-speed videolaryngoscopy (HSV) allows the visualization of non-periodic vibratory motion of vocal fold beyond the limitation of videostroboscopy. New developed post-processing methods that converts HSV to two-dimensional videokymography (2D VKG) using U-medical image-processing software can provide quantitative information on vocal fold mucosa vibration. Multifunctional laryngeal examination system is composed of 3 kinds of examinations such as HSV, 2D scanning digital kymography (2D DKG) and line scanning digital kymography (DKG). Evaluation of entire vocal cord vibratory pattern in each cord is possible using 2D DKG and a faster and more reliable quantitative information can be obtained. As this system is used in clinical and research, it is expected to bring much advances to the diagnosis of voice disorders. In this review, I will introduce the principles and advantages on examination of the vocal fold vibration, which is in the spotlight recently, and proceed with the literature review.

• The Journal of Korean Physical Therapy
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• 제34권3호
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• pp.98-103
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• 2022

Purpose: New therapeutic approaches have emerged to improve gait ability in patients with brain damage, such as action observation learning (AOT), auditory cueing, motor imagery etc. We attempted to investigate the effects of AOT with auditory cueing (AOTAC) on gait function in patients with stroke. Methods: The eighteen stroke patients with a unilateral hemiparesis were randomly divided into three groups; the AOTAC, AOT, and control groups. The AOTAC group (n=8) received training via observing a video that showed normal gait with sound of footsteps as an auditory cue; the AOT group (n=6) receive action observation without auditory stimulation; the control group (n=5) observed the landscape video image. Intervention time of three groups was 30 minutes per day, five times a week, for four weeks. Gait parameters, such as cadence, velocity, stride length, stance phase, and swing phase were collected in all patients before and after each training session. Results: Significant differences were observed among the three groups with respect to the parameters, such as cadence, velocity, stride length, and stance/swing phase. Post-hoc analysis indicated that the AOTAC group had a greater significant change in all of parameters, compared with the AOT and control groups. Conclusion: Our findings suggest that AOTAC may be an effective therapeutic approach to improve gait symmetry and function in patients with stroke. We believe that this effect is attributable to the change of cortical excitability on motor related to cortical areas.

• 무역학회지
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• 제47권1호
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• pp.63-77
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• 2022

As customer needs for eco-friendly transportation services increase, strategies of major global shipping companies are being established to meet them. Even if logistics costs increase, more and more shippers are choosing shipping companies that fulfill their social responsibilities through decarbonization, and against this backdrop, global shipping companies want to strengthen corporate social responsiveness and reduce shipping environmental costs. In the post-corona era after COVID-19, it is necessary to review the latest Green Shipping management strategies of shipping companies emerging as a new normal for the shipping and logistics industries. This study aims to explore trends in the latest Green Shipping management strategies of global shipping companies pursuing environmental load suppression in the shipping and logistics fields. Among the previous studies, some studies analyzed the green shipping policies of major shipping countries, but they did not deal with the latest policies over time, and few previous study has conducted a fact-finding analysis on the latest Green Shipping management strategies of major shipping companies at the corporate level. This study attempted to analyze securities reports by major domestic and international shipping companies and to present the latest Green Shipping management strategies by shipping companies.

• Asian-Australasian Journal of Animal Sciences
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• 제23권9호
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• pp.1184-1189
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• 2010

This work was conducted to examine the variation of immunoglobulins (Igs) in serum, immune milk, normal milk and colostrum upon implantation of a new Antigen Releasing Device (ARD). The core of each ARD housed an immunostimulating complex (ISCOM) that was made of adjuvant Quil A and type XIII lipase from a Pseudomonas sp. Each ARD was coated with polylactic acid, known as polylactide, that controls antigen release. Twenty lactating Chinese Holstein cows were divided into 2 groups (n = 10): test group and control group. All cows in the test group were implanted with a single injection in the right iliac lymph node with 3 types of ARDs, which were designed to release the antigens at d 0, 14 and 28 post-implantation. Blood and milk samples were collected from both groups, and colostrum samples were also collected from other post-partum cows in the same farm. Concentrations of $IgG_1$, IgA and IgM in whey and serum were measured by sandwich ELISA. The results showed that the $IgG_1$, IgA and IgM concentrations in serum and whey from the test group were higher than from the control group. Among the three Igs measured, the $IgG_1$ concentration in serum was significantly higher at d 40 after ARD implantation, and the $IgG_1$ concentration in whey peaked at d 9, 17 and 30, which corresponded with release of the antigen. Based on Pearson's correlation between Ig concentration and production parameters, IgA concentration in normal milk was positively correlated with lactation period, which reflected IgA changes during the lactation period in immune milk. In colostrum, $IgG_1$, IgA and IgM decreased abruptly from d 0 to 3, and then decreased slightly. In conclusion, serum $IgG_1$ concentration can be affected by controlled release of the ARD, while whey IgA levels are primarily affected by lactation period. These results may be useful in future studies designed to regulate concentrations of Igs in immune milk.

• 한국초등수학교육학회지
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• 제15권1호
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• pp.19-38
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• 2011

본 연구의 목적은 개방형 수학 문제 해결 과정에서 수학 영재교육 대상 학생과 일반 학생의 문제해결 전략과 그 해결 과정에서 보이는 행동 특성을 비교 분석하는 것이다. 이 분석을 토대로 일반 수학 수업에서의 영재교육 대상 학생들을 위한 창의성을 강조한 수업의 가능성을 탐구하였다. 이를 위해 수학 영재교육 대상 학생집단과 일반 학생 집단을 다단계 군집표집하여 수학 영재교육 대상 학생 55명과 일반 학생 100명을 선정하여 다양한 해법이 가능한 개방형 문제를 6개월 동안 제시하여 해결 전략 및 행동 특성을 분석하였다. 행동특성은 수업 관찰과 활동지 분석 및 개별 면담을 사용하였다. 연구결과 수학 영재 교육 대상 학생들이 일반 학생들에 비하여 다양한 전략을 보여 주었으나 많은 수학 영재교육 대상 학생도 고차원적 조작 능력이 미흡하였다. 또한 수학 영재교육 대상 학생의 행동 특성은 일반에 비하여 집착력이 강하고 다양한 해법을 추구하는 면에서 뛰어났다. 그런데 과제의 특성에 따라서 반응의 양상이 다르게 나타나므로 수학 영재교육 대상 학생의 수준과 능력에 맞게 다양한 유형의 과제를 개발하여 제시할 필요가 있다.

• 시큐리티연구
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• 제9호
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• pp.133-153
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• 2005

산업화와 도시화에 따른 각 계층의 다양한 경호서비스 수요를 충족시켜 줄 수 있는 연구와 효율적인 운영방안이 절실히 필요한 시점이다. 경호업체들 중 상당수의 업체들이 부실경영과 자본력의 압박, 인력관리능력부족 등으로 인하여 인프라를 구축하지 못하고 파산하거나 영세성을 면치 못하고 있다. 민간경호업무의 효율적인 운영방안을 다음과 같이 제시하고자 한다. 첫째, 제도적 관점을 통한 운영 방안으로 새로운 민간경호만의 법 제정과 국가적 차원에서 보다 많은 지원이 필요하고, 영세 업체간의 구조조정과 인수합병을 실시, 최저가격제도로 운영하여야 한다. 둘째, 민간경호시장 구조적 측면에서 운영방안으로 경호원을 위한 전문교육기관 설치, 적정수준의 보수확보와 후생복지제도의 확충, 경호에 대한 사회적 인식변화에 노력함과 경호업체의 특성과 능력에 따라 한 분야의 전문영역을 개발해 나가야 한다. 셋째, 민간경호업무 운영시스템 구축을 통한 운영방안으로 우수한 경호인력의 확보, 끊임없는 홍보 마케팅 전략 수립과 시행시스템 구축, 의뢰자에게 높은 신뢰성 구축, 평상시 경호원교육훈련 시스템 구축, 사후 경호의뢰자 관리 시스템 구축, 개별업체의 특성에 맞는 시스템을 구축하여야 한다.