• Journal of Chest Surgery
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• 제13권2호
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• pp.118-124
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• 1980

A double aorto-coronary bypass procedure performed in 2 cases, one with a Prinzmetal`s variant angina and the other with an unstable angina, is presented. The patient with a Prinzmetal`s angina who had a high-grade obstruction of the left anterior descending and the right coronary system showed a marked postoperative improvement with complete disappearance of anginal pain. The other patient with unstable angina had obstruction of the left anterior descending as well as a marginal branch of the left circumflex artery. Following bypass of these vessels, the patient did well during the immediate postoperative period. However, he developed hypotension in the recovery room and died 6 hours postoperatively, in spite of an intensive effort at resuscitation. The most likely cause of death in this patient is a myocardial infarction.

• 대한간호학회지
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• 제21권1호
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• pp.5-15
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• 1991

The present study was undertaken in an effort to investigate the effects of alcohol on survival of mice and on their humoral and cellular immune responses, The immune responses examined were Arthus and delayed-type hyperrsnesitivity(DTH) reactions to sheep red blood cells(SRBC), contact hypersensitivity to dinitrofluorobenzend(DNFB), antibody response to thymus - dependent SRBC and to thymus -independent polyvinylpyroridone(PVP), and the recovery of Crytococcus neoformans from the liver, spleen, kidney and brain of experimentally infected mice. The administration of ethanol concentrations of 20% or less did not cause any change in survival rates as compared withs saline injected control group. In general, ethanol administration inhibited the Arthus and DTH reactions to SRBC, contact hypersensitivity to DNFB, and antibody response to both SRBC and PVP and it also decreased the resistance of mice to C. neoformans infection. Taken together, the present study stongly suggested that ethanol inhibits immune response and decrease the resistance of mice to C. neoformans infection.

• 한국생산제조학회지
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• 제23권2호
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• pp.157-163
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• 2014

In this paper, a robust MRAC (model reference adaptive control) scheme is applied to control an electrohydraulic positioning system under various loads. The inverse dead-zone compensator in the control system cancels out the dead-zone response, and an integrator added to the controller provides good position-tracking ability. LQG/LTR (linear quadratic Gaussian control with loop transfer recovery) closed-loop model is used as the reference model for learning the MRAC system. LQG/LTR provides a systematic technique to design the linear controller that optimizes the objective function using some compromise between the control effort and the system performance in the frequency domain. Different external load tests are performed to investigate the effectiveness of the designed MRAC system in real time. The experimental results show that the tracking performance of the proposed system is highly accurate, which offers considerable robustness even with a large change in the load.

• Journal of Power Electronics
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• 제14권4호
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• pp.621-631
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• 2014

To invigorate the tapped-inductor boost (TIB) topology in emerging high step-up applications for off-grid products, a lossless snubber consisting of two capacitors and three diodes is proposed. Since the switch voltage stress is minimized in the proposed circuit, it is allowed to use a device with a lower cost, higher efficiency, and higher availability. Moreover, since the leakage inductance is fully utilized, no effort to minimize it is required. This allows for a highly productive and cost-effective design of the tapped-inductor. The proposed circuit also shows a high step-up ratio and provides relaxation of the switching loss and diode reverse-recovery. In this paper, the operation is analyzed in detail, the steady-state equation is derived, and the design considerations are discussed. Some experimental results are provided to confirm the validity of the proposed circuit.

• Journal of Information Processing Systems
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• 제13권6호
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• pp.1585-1601
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• 2017

With the rapid development of computer technologies, a number of image modification methods have emerged, which have great impacts on the security of image information. Therefore, it is necessary to protect the integrity and authenticity of digital images, and digital watermarking technique consequently becomes a research hotspot. An effort is made to survey and analyze advancements of image watermarking algorithms based on singular value decomposition (SVD) in recent years. In the first part, an overview of watermarking techniques is presented and then mathematical theory of SVD is given. Besides, SVD watermarking model, features, and evaluation indexes are demonstrated. Various SVD-based watermarking algorithms, as well as hybrid watermarking algorithms based on SVD and other transforms for copyright protection, tamper detection, location, and recovery are reviewed in the last part.

• 한국환경과학회지
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• 제22권11호
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• pp.1529-1538
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• 2013

Disasters like mountain landslides and collapse in cutting areas claim many a life and cause economic losses, involving much effort and expenses for their recovery. This study has surveyed and analyzed incident of disasters that had occurred on the sloping sides in Korea for the past 13 years in an effort to relieve damage caused by disasters on the sloping sides. The analysis confirms that while the major cause of disasters on the sloping side was storms in the past, frequency of disasters on sloping sides caused by local downpour is steadily on the rise. In addition, while disasters were concentrated in Gangwon Province, a mountainous region of the country, frequency of disasters occurring on the sloping sides is steadily increasing recently on the sloping sides in downtown areas in Seoul, Gyeonggi-do and so forth, attributing a large percentage of disasters to sloping sides. Data surveyed and analyzed in this study are thought to be applicable as basic data for the establishment of effective measures for the prevention of disasters occurring on the sloping sides in the days to come.

• 한국콘텐츠학회논문지
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• 제9권9호
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• pp.235-242
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• 2009

이 연구는 생물테러리즘을 위기로 인식하고 생물테러리즘을 위기관리별로 어떻게 관리할 것인가에 대한 관리방안을 연구하는데 그 목적이 있다. 9.11 테러 이후 발생한 탄저균 테러는 전 세계에 생물병원체에 의한 공포감을 인식시켜 주었으며, 그 위험성이 강조된 사례이다. 본 연구결과 생물테러리즘 위기는 4단계로 구분하여 관리할 때 완화 및 예방단계에서는 테러리즘의 기준을 정하고, 대비를 하기 위하여 테러관련 법을 제정하고, 조기발견을 위한 감시체계를 확보해야 한다. 대비단계에서는 초동조치 팀을 편성하고 교육훈련을 통해 대응하는 요령을 숙달시켜야 하며, 각종 자원을 확보해야 한다. 대응단계에서는 숙달된 초동조치팀이 즉각 투입되어 현장 정리 및 확산을 방지해야 하며, 복구단계에서는 평가체제를 구축하여 조기에 정상적인 생활로 복귀할 수 있도록 조치해야 한다.

• 한국수소및신에너지학회논문집
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• 제21권6호
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• pp.570-579
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• 2010

Since the temperature of waste heat source is relatively low, it is difficult to maintain high level of efficiency in power generation when the waste heat recovery is employed in the system. In an effort to improve the thermal efficiency and power output, use of ammonia-water mixture as a working fluid in the power cycle becomes a viable option. In this work, the performance of ammonia-water mixture based Rankine cycle is thoroughly investigated in order to maximize the power generation from the low temperature waste heat. In analyzing the power cycle, several key system parameters such as mass fraction of ammonia in the mixture and turbine inlet pressure are studied to examine their effects on the system performance. The results of the cycle analysis find a substantial increase both in power output and thermal efficiency if the fraction of ammonia increases in the working fluid.

• Journal of Korean Neurosurgical Society
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• 제37권4호
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• pp.300-302
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• 2005

The authors report a case of hyperacute, massive hemorrhage in the left basal ganglia with severe midline shift that was treated successfully by the ultrasound-monitored free hand aspiration technique. Every effort was made to shorten time until removal of considerable amount of the hematoma and minimize duration of cerebral herniation, avoiding additional irreversible neurological deficit. A burr hole aspiration technique was preferred to standard craniotomy procedure, and any time-consuming procedures such as stereotactic frame application were abandoned. A burr hole was localized on the basis of computed tomography images simply and quickly with a ruler, and safety of the aspiration procedure was augmented by real-time ultrasound monitoring. Such minimally invasive technique relieved cerebral herniation successfully while avoiding time consumption and the morbidity of major craniotomy procedure. Early resuscitation of the patient with cerebral herniation in this case resulted in excellent recovery of the patient's neurological deficit. The patient's mentality started to improve rapidly and was clear six months after the surgery.

• 식물분류학회지
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• 제41권3호
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• pp.182-193
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• 2011

As a part of the on-going effort to conserve endangered Scrophularia takesimensis Nakai in Korea, its genetic structure and diversity from 3 population, consisted of 14 subpopulations in Ulleung Island were analyzed using RAPD band patterns. Out of 60 primers tested, 33 generated amplified bands with its genome, including 149 polymorphic and 67 monomorphic bands. The highest number (146) was found in northern population, especially, 64 in HY subpopulation; the smallest (40) in eastern population. An examination of its genetic structure with AMOVA revealed that about 60% of all variations could be assigned to among subpopulations within populations. Population differentiation among populations and subpopulations is seriously going now because of habitat fragmentation due to human activities, such as road and small port construction. Although the habitats of S. takesimensis in Ulleung Island, Korea are disappeared at an alarming rate, significant levels of genetic variation still exist at species level, and population level, especially northern population. Therefore, three conservation strategies should be needed urgently; 1) preservation of populations as it stands, 2) establishment of recovery plan to connect population and subpopulations genetically, and 3) long-term monitoring.