• 에너지공학
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• 제10권3호
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• pp.188-194
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• 2001

정유공장으로부터 발생하는 중잔사유를 이용하는 가스화 복합발전 플랜트에 대한 공정모사를 수행하였다. 가스화 복합사이클의 발전계통을 모델링하기 위해 본 연구는 MS7001FA 가스터빈이 공기분리장치와 연계되어 있고, 공기분리장치를 위한 공기 추출과 공기분리장치로 부터의 질소희석이 이루어진다고 가정하였다 가스터빈의 폐열은 삼중압력의 페열회수 증기발생장치로부터 회수하였다. 가스터빈의 합성가스 연료는 중잔사유가 Shell 가스화 및 Sulfinol-SCOT-Claus 공정을 거쳐 발생되는 것으로 가정하였다. 공정 최적화 결과로부터, 가스화 복합사이클의 효율이, 질소 희석이 없는 경우와 있는 경우에 대해, 공기추출비 20% 또는 40∼60%에서 가장 우수했다. 그리고, 연소지의 질소희석은 NOx 저감에 매우 바람직하고 현저한 효과를 가져오나, 반면에 가스터빈의 운전조건을 써지 조건에 가깝게 이동시킴을 알 수 있었다.

• 대한치과마취과학회지
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• 제10권2호
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• pp.172-177
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• 2010

Background: Damages of trigeminal nerve, particularly inferior alveolar nerve and lingual nerve, could occur following dental procedures. In some cases, nerve damage may happen as a complication of the local anesthetic injection itself and not of the surgical procedure. Methods: From September 2006 to August 2010, 5 cases of inferior alveolar nerve and lingual nerve damages, which were assumed to happen solely due to local anesthesia, were reviewed. All cases were referred to Division of Oral and Maxillofacial Surgery, Department of Dentistry, Hanyang University Medical Center for legal authentication in the process of criminal procedure. Results: In all five cases, patients complained of altered sensation occurred in the distribution of the inferior alveolar or lingual nerve following block anesthesia. The local anesthetics were 2% lidocaine with 1 : 100,000 epinephrine and the amount of local anesthetics, which were used during injection, were varied. Most of patients experienced the electric stimulation during injection. Recovery was poor and professional supportive care was mostly absent. Conclusions: Dental practitioners should consider that the surgical procedure caused the trigeminal nerve damage, however, dental local anesthesia for inferior alveolar nerve and lingual nerve could be one of the causes for damages. The various mechanisms for nerve damages by local anesthesia are thoroughly discussed.

• 대한한의학회지
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• 제20권3호
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• pp.66-76
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• 1999

The purpose of this study was to asses the etlect of Uncaria rhynchophylla (UR). one of the oriental herbs having a capability to block calcium channels, on affecting vestibular compensation (VC) in Sprague - Dawley rats. Animals were divided into a drug treatment group receiving, UR per oral for 10 days preceding unilateral labyrinthectomy (ULX) and a control group with saline ingestion, To evaluate behavioral changes. horizontal spontaneous nystagmus (SN) and roll head tilt (RHT) were recorded by a video camem with zoom lens in the course of vestibular compensation (VC). Immunohistochemical staining was performed by conventional ABC method to visualize cFos-like immunoreactive (cFLI) neurons in the medial vestibular nuclei (MVN) and cFLI cells were counted by image analyzer. Bodyweight was increased significantly, about 35g, by UR treatment for 10 clays before ULX. Compared with the control group, the drug group showed significant reduction of RHT 6 hrs after ULX as well as fast disappearance of SN at early stages of vestibular compensation. Also, recovery of the spatial and temporal cFLI expressions in the bilateral MVN was accelerated 24 hrs after ULX. These results suggest that Uncaria rhynchophyila has a beneficial effect to ameliorate vestibular compensation in unilateral labryinthectomized rats.

• 한국태양에너지학회 논문집
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• 제40권2호
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• pp.25-36
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• 2020

The Korean government has a plan to mandate zero-energy buildings in 2020 for public and 2025 for private buildings. In order to design a zero-energy building, insulation and airtightness, which are the most basic elements of passive house technology, are required, and the government has been accomplished this through step-by-step strengthening of related standards. In passive house with high thermal insulation and airtightness performance, the heat introduced into the building through solar radiation can be stored for a long time to keep the inside warm during winter. On the other hand, during summer, heat introduced into the building cannot be easily released to outside, so it is necessary to actively block solar radiation and high temperature outdoor air to prevent an increase of indoor temperature. Therefore, this study aims to derive an appropriate operation condition of passive house to maintain the indoor temperature at an suitable level according to the ventilation methods and solar shading conditions. As a result, under the conditions that the outdoor temperature was 28℃ or less, the ventilation using a heat recovery ventilation system at daytime and natural ventilation at nighttime were selected for the most appropriate operation method. In addition, in the case of solar shading, it was found that blocking solar radiation at daytime using the blind and open the blind at nighttime to ensure natural ventilation were selected for the most appropriate solar shading condition.

• 대한족부족관절학회지
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• 제18권3호
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• pp.115-118
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• 2014

Purpose: The purpose of this study is to report on the result of repairing Achilles tendon using absorbable suture under nerve block. Materials and Methods: We retrospectively reviewed 20 patients with acute Achilles tendon rupture who were followed up for at least six months after the operation. We repaired Achilles tendon using two absorbable sutures using the Krackow technique for the proximal stump and the Kessler technique for the distal stump. A programmed postoperative management including non-weight bearing with a short leg cast for four weeks after the operation was applied for all patients. We evaluated clinical results using American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS) for satisfaction, range of motion of ankle, functional recovery rate, and the starting time of single heel raise. Results: The mean VAS score for satisfaction and AOFAS score was 9.2 and 93.0, respectively. The affected ankle showed a mean dorsiflexion rate of 90% and plantar-flexion rate of 94% compared to the uninjured side. The single heel raise could start at a mean of 3.5 months after the operation. Conclusion: Treatment of Achilles tendon rupture with absorbable suture material using the hybrid suture technique of proximal Krackow and distal Kessler showed sufficient stability and minimal chronic inflammatory reaction.

• 정보보호학회논문지
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• 제29권5호
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• pp.1153-1165
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• 2019

최근 국방 분야를 포함한 국가정보통신망 및 주요 기반시설 등에 대한 해킹 위협이 증가하고 있다. 국방정보시스템은 망분리를 통해 외부로부터의 위협에 대응하고 있으나, 해킹 성공시 전 평시 군사작전에 큰 영향을 미치게 된다. 오늘날 사이버 공격과 위협은 예측 불가능한 수준으로 높아지고 있어 해킹 위협을 완전히 차단하고 예방하는 것은 현실적으로 불가능하다. 따라서 본 연구에서는 국방정보시스템의 사이버 공격 징후가 예상되거나 발생했을 경우 신속한 대응 및 시스템의 생존성을 보장하고 지속성을 유지할 수 있는 능력인 '사이버복원력(Cyber Resilience)'의 수준을 평가할 수 있는 성숙도모델을 제시하였다. 제시된 성숙도모델을 통해 국방정보시스템의 사이버복원력 수준을 평가하고 부족한 분야를 식별 및 보완함으로써 국방정보시스템의 사이버보안 수준을 향상시키는데 기여할 수 있을 것으로 기대된다.

• Physical Therapy Rehabilitation Science
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• 제3권1호
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• pp.7-12
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• 2014

Objective: The purpose of this study was to investigate the effects of a three dimensional balance trainer in combination with a video-game system and visual feedback on balance recovery and gait function in subacute stroke patients. Design: Randomized controlled trial. Methods: Twenty-three subacute stroke patients were assigned to either an experimental (n=12) or a control group (n=11) using a random permuted block design and sealed envelopes. The experimental group received additional 3-dimensional balance training combined with visual feedback and a game program for 30 min/day, 5 days/week for 4 weeks. Both groups received 30-min of conservative physical therapy sessions based on neurodevelopmental therapy. Before and after the 20 sessions, walking abilities were evaluated by the the GaitRite system and balances were evaluated using the Berg Balance Scale (BBS). The Trunk Impairment Scale (TIS) was used to assess trunk muscle performances. Results: After the 4-week intervention, BBS and TIS scores were significantly increased in both groups (p<0.05), and increases in these scores were significantly greater in the experimental group (p<0.05). After the 4-week intervention, gait speed and cadence were significantly increased in both groups (p<0.05), and as was observed for BBS and TIS scores, changes of gait speed and cadence were significantly greater in the experimental group (p<0.05). Conclusions: The study shows that the 3-dimensional balance trainer combined with visual biofeedback and a video-game system provides a therapeutic means for improving balance and gait ability in subacute stroke patients.

• 대한화학회지
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• 제65권4호
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• pp.254-259
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• 2021

The purpose of this work is the development of a method for an effective, less expensive, rapid, and simultaneous determination of three phenolic compounds (caffeic acid, gallic acid, and quercetin) widely present in food resources and known for their antioxidant powers. The method relies on partial least squares (PLS) calibration of UV-visible spectroscopic data. This model was applied to simultaneously determine, the concentrations of caffeic acid (CA), gallic acid (GA), and quercetin (Q) in six herb infusion extracts: basil, chive, laurel, mint, parsley, and thyme. A wavelength range (250-400) nm, and an experimental calibration matrix with 21 samples of ternary mixtures composed of CA (6.0-21.0 mg/L), GA (10.0-35.2 mg/L), and Q (6.4-17.5 mg/L) were chosen. Spectroscopic data were mean-centered before calibration. Two latent variables were determined using the contiguous block cross-validation procedure after calculating the root mean square error cross-validation RMSECV. Other statistic parameters: RMSEP, R², and Recovery (%) were used to determine the predictive ability of the model. The results obtained demonstrated that UV-visible spectrometry and PLS regression were successfully applied to simultaneously quantify the three phenolic compounds in synthetic ternary mixtures. Moreover, the concentrations of CA, GA and Q in herb infusion extracts were easily predicted and found to be 3.918-18.055, 9.014-23.825, and 9.040-13.350 mg/g of dry sample, respectively.

• 한국정보통신학회논문지
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• 제23권7호
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• pp.801-806
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• 2019

최근 각 대학에서 소프트웨어교육을 강조하여 교양과목에 많이 편성하고 있다. 하지만 학생들은 프로그래밍 학습을 어려워하거나 프로그래밍 학습 동기가 부족하거나 배우려고 하는 의욕이 없는 경우가 많다. 본 연구에서 회복탄력성을 알아보고자 하는 이유는 프로그래밍 학습의 실패를 극복하여 포기하지 않고 다시 학습을 진행할 수 있는 회복하는 힘을 가질 수 있도록 지도하기 위함이다. 본 연구에서는 스크래치를 학습하는 학생 집단과 파이썬을 학습하는 학생 집단을 대상으로 회복탄력성 사전-사후 검사를 진행하였다. 연구결과로는 스크래치는 학생들이 다소 쉽게 받아들이고 열심히 하려는 모습을 보였지만, 파이썬은 상대적으로 스크래치보다 어려움이 있었음을 알 수 있었다. 본 연구를 통하여 프로그래밍 학습을 지속할 수 있는 요인을 파악하는데 도움이 될 것이라고 기대한다.

• Journal of Power Electronics
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• 제19권4호
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• pp.881-893
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• 2019

This paper proposes a practical sliding-mode controller design for shaping the impedances of cascaded boost-converter power decoupling circuits for reducing the second order harmonic ripple in photovoltaic (PV) current. The cascaded double-boost converter, when used as power decoupling circuit, has some advantages in terms of a high step-up voltage-ratio, a small number of switches and a better efficiency when compared to conventional topologies. From these features, it can be seen that this topology is suitable for residential (PV) rooftop systems. However, a robust controller design capable of rejecting double frequency inverter ripple from passing to the (PV) source is a challenge. The design constraints are related to the principle of the impedance-shaping technique to maximize the output impedance of the input-side boost converter, to block the double frequency PV current ripple component, and to prevent it from passing to the source without degrading the system dynamic responses. The design has a small recovery time in the presence of transients with a low overshoot or undershoot. Moreover, the proposed controller ensures that the ripple component swings freely within a voltage-gap between the (PV) and the DC-link voltages by the small capacitance of the auxiliary DC-link for electrolytic-capacitor elimination. The second boost controls the main DC-link voltage tightly within a satisfactory ripple range. The inverter controller performs maximum power point tracking (MPPT) for the input voltage source using ripple correlation control (RCC). The robustness of the proposed control was verified by varying system parameters under different load conditions. Finally, the proposed controller was verified by simulation and experimental results.