• Structural Engineering and Mechanics
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• 제11권5호
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• pp.565-574
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• 2001

Experimental investigation into the behaviour of half-scale brick masonry panels were conducted under cyclic loading normal to the bed joint and parallel to the bed joint. For each cycle, full reloading was performed with the cycle peaks coinciding approximately with the envelope curve. Unloading, however, was carried out fully to zero stress level and partially to two different stress levels of 25 percent and 50 percent of peak stress. Stability point limit exhibits a unique stress-strain curve for full unloading but it could not be established for partial unloading. Common point limit was established for all unloading-reloading patterns considered, but its location depends on the stress level at which unloading is carried to. Common point curves were found to follow an exponential formula, while residual strains versus envelope strains can be expressed by a polynomial function of a single term. The relation between residual strain and envelope strain can be used to determine the stress level at which deterioration due to cyclic loading began.

• 제어로봇시스템학회논문지
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• 제10권12호
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• pp.1119-1126
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• 2004

This paper presents optimized structured treatment interruption to reduce medication and establish long-term immune response against HIV-infection. Understanding HIV-related immune system control enables better HIV therapy without using full­treatments. Discrete regimen and continuous regimen characteristics are compared. Controllability of HIV-related immune system is analyzed for better understanding of optimal control in HIV therapy. Using optimal control provides more effective therapy than the full treatment without interruption in terms of controllability analysis. Case studies indicates that the proposed therapy induces long-erm non-progression while preserving high CD4 T-helper cell count and low virus load in HIV-infected patients.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.193_194
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• 2009

본 논문은 장기 전압 안정도 분석을 위한 프로그램 개발을 목적으로 한다. 장기 전압 불안정 현상은 전력 계통에 투입되어 있는 무효전력과 관련된 제어기 중에서 그 동작특성이 수 분에서 수십 분에 이르는 제어기에 의해 발생한다. 기존에 장기 전압 안정도 분석에는 상용툴의 Full-time Domain 알고리즘을 이용하였다. 하지만 기존의 Full-time Domain 알고리즘에 의해 장기 전압 안정도 분석을 하게 되면 그 연산 시간이 매우 오래 걸릴 뿐만 아니라, 시적분에 의한 수치 에러로 인하여 정확성을 보장할 수 없다. 본 논문에서는 장기 전압안정도 분석을 하기 위해 준동적 시모의 알고리즘(Quasi-Steady-State Algorithm)을 도입하였다. 준동적 시모의 알고리즘을 적용한 프로그램을 보이고, 이에 따fms 모의를 한구전력계통에 적용하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.470-473
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• 1995

There exist two critical in application of the magnetic bearing system. One is the control axis interference caused by gyroscopic effect and the other is the vibration caused by the unbalance on the rotor. To solve both problems at the same time, first, a centralized full-state feedback controller based on the LQR control theory was designed to compensate for the gyroscopic effect. Second, disturbance rejection control input based on the observer was designed to avoid the vibration causer by the unbalanced rotor. Balancing input computer accroding to LQR and output of the observer were derived in term of rotational speed. Effectiveness of the on-line balancing was verified through numerical simulation. The developed observer-based controller was also applied to the linear and nonlinear magnetic bearing systems.

• Medical Lasers
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• 제10권4호
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• pp.246-249
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• 2021

The carbon dioxide (CO₂) laser is one of the treatment options used for xanthelasma palpebrarum. However, even if the full dermal layer is removed, the lesion can recur due to the residual lipid deposits. A 44-year-old male patient with xanthelasma on both upper eyelids was treated with a pulsed dye CO₂ laser. On the right upper eyelid, we carried out a CO₂ laser treatment until the yellowish plaque was almost invisible and the full thickness of the dermal layer was removed. On the left upper eyelid, the dermal layer was partially removed and an additional squeezing out of yellowish particles was done. The lesion treated by the squeezing out of lipid droplets showed better long-term results than the lesion treated up to the deeper dermal layer.

• Asia pacific journal of information systems
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• 제32권3호
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• pp.564-579
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• 2022

The use of on-premises technology in the business environment to create a competitive advantage is ushering in a new era known as digital transformation. As the foundation of digital transformation of enterprises, information technology still has a paradoxical effect on enterprises. This paper documents the effect of investments in IT on a firm's long-term profitability performance measures as return on assets (ROA), as well as tests whether the earlier entrant and the later entrant are different in IT investment performance. Using a sample of China's public firms IT investment data between 2016 and 2019, the result indicates that IT investment in firms have a positive effect on firm performance in full sample, but not in the financial industry firms. When it comes to the different investment time, the result shows no significant difference between the earlier entrant firm and the later entrant firm in the full sample, but not in the case of software industry sample. This should help alleviate the concerns that some have expressed about the viability of digital transformation given the highly publicized IT investment and implementation problems at some firms.

• The Journal of Advanced Prosthodontics
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• 제3권1호
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• pp.51-55
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• 2011

BACKGROUND. Mandibular displacement is a common complication of condylar fracture. In the mandibular displacement due to condylar fracture, it is difficult to restore both esthetics and function without using orthognathic surgery. CASE DESCRIPTION. This clinical report described a full mouth rehabilitation in the patient with bilateral condylar fractures and displaced mandible using bilateral sagittal split ramus osteotomy (BSSRO) and simultaneous dental implant surgery. Mandibular position was determined by model surgery through the diagnostic wax up and restoration of fractured teeth. The precise amount of the mandibular shift can be obtained from the ideal intercuspation of remaining teeth. CLINICAL IMPLICATION. Mandibular displacement by both condylar fractures can be successfully treated by orthognathic surgery. Determination of occlusal plane and visualization from diagnostic wax up are mandatory for mandibular repositioning of model surgery. Stable occlusion and regular recall check up are needed for long-term outcome.

• Journal of Digestive Cancer Research
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• 제5권1호
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• pp.44-49
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• 2017

Background: 최근 제안된 조기위암에 대한 미세침습 치료법은 내시경점막하박리술(endoscopic submucosal dissection, ESD)혹은 종양 부위를 전층 절제(endoscopic full-thickness gastric resection, EFTGR)을 통해 위 절제를 최소화하고 동시에 복강경을 통해 감시림프절 절제(sentinel lymph node dissection, SLND)를 시행함으로써 그 가능성을 제시했었고, 이들을 각각 ESN (endoscopic submucosal dissection with laparoscopic sentinel lymph node dissection), Hybrid-NOTES (endoscopic full-thickness gastric resection with laparoscopic sentinel lymph node dissection)라고 명명하였다. 본 고에서는 림프절 전이 위험성이 높은 조기위암에 대해 이 두 치료법을 시행받은 환자들의 장기 추적 결과를 평가하고자 한다. Methods: 이 후향적 연구는 2009년 1월부터 2013년 5월 중에 ESN 혹은 Hybrid-NOTES를 시행받은 환자들이 포함되었다. Results: 총 42명의 환자들이 연구에 포함되었고, ESN 21명, Hybrid-NOTES 21명이 각각 등록되었다. ESN을 시행받은 21명 중 4명, Hybrid-NOTES를 시행받은 5명은 이 미세침습수술 후 추가 수술을 받아야 했다. 아직까지 이 수술 후 사망 환자는 없지만 ESN을 시행받은 1명의 환자에서 림프절 전이가 발견되어 항암치료를 받고 있다. Conclusion: 조기위암의 미세침습 수술인 ESN 혹은 Hybrid-NOTES는 좋은 장기 추적 결과를 보여주었다. 이 방법들은 향후 림프절 전이 위험성이 높은 조기위암에서 ESD와 gastrectomy 사이에 속한 환자들에게 좋은 치료법이 될 수 있을 거라고 생각된다.

• 한국지반공학회지:지반
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• 제12권3호
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• pp.63-72
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• 1996

판앵커들은 각종 해양공사와 해양구조물의 유지관리작업에 빈번히 사용되고 있다. 판앵커가 연약한 점토에 근입되었을 때 지속적인 허용하중을 받게 되면 Creep현상이 발생될 수도 있다. 본 논문은 얕은 원형앵커가 순극한 상향인발력보다 작은 순하중을 지속적으로 받았을 때 시간이 경과함에 따라 발생되는 크리프효과를 연구한 실내모델실험 결과를 기술하였다. 실내모델시험 결과를 바탕으로 순하중과 상향변위율 및 경과시간사이의 상관관계식을 제시하였다.

• 대한치과의사협회지
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• 제50권7호
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• pp.384-393
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• 2012

Successful treatment of a badly broken down tooth with pulpal disease depends not only on good endodontic therapy, but also on good prosthetic reconstruction of the tooth after endodontic therapy is completed. The ideal treatment of endodontically treated teeth has been widely and controversially discussed. Endocrown is a restorative option for endodontically treated teeth. Endocrown design incorporates the core and short post into the crown as a single restoration. The preparation of endocrown consists of a circular equigingival butt-joint margin and central retention cavity of the entire pulp chamber instead of employing intraradicular posts. This design significantly increases the surface area of the preparation available for cementation. It is particularly useful in young patient teeth for long-term provisional restoration and in teeth with short clinical crowns. This technique represents a promising and conservative method for the treatment of endodontically treated teeth that require long-term protection and stability. Endocrown can be considered as a feasible alternative to full crowns or composite overlays for the restoration of non vital teeth.