• 비파괴검사학회지
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• 제27권2호
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• pp.164-172
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• 2007

콘크리트 구조물에서 발생하는 균열은 구조물의 심각한 성능 저하와 파괴를 유발할 수 있으며, 따라서 이러한 균열 손상의 조기 탐지 및 평가, 보수는 구조물의 건전성에 있어서 매우 중요한 부분이다. 특히, 균열의 평가를 위한 많은 방법들이 제안되었으며, 그 중에서도 자기 보정 표면파 투과 기법을 이용한 균열 깊이 추정법은 다른 방법에 비하여 균열의 깊이 변화에 가장 민감한 장점이 있는 방법이다. 그러나 자기 보정 표면파 투과 기법은 주파수에 따른 투과 함수의 변동성으로 인하여 정량적인 평가는 아직 어려운 실정이다. 본 연구에서는 측정된 자기 보정 표면파 투과 함수의 스펙트럼 에너지를 이용하여 균열 깊이를 추정하는 기법을 제안하고자 하며, 이 기법의 유효성을 판단하기 위하여 다양한 균열 깊이를 가진 콘크리트 슬래브를 이용하여 실험적인 연구를 수행하였다. 연구 결과 제안된 방법이 균열 깊이 평가에 유효하게 사용할 수 있으며, 또한 기존의 방법에 비하여 보다 정확한 균열 깊이를 추정하는 방법임을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권4호
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• pp.588-595
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• 2013

Mesenchymal stem cells (MSCs) are often known to have a therapeutic potential in the cell-mediated repair for fatal or incurable diseases. In this study, canine umbilical cord MSCs (cUC-MSCs) were isolated from umbilical cord matrix (n = 3) and subjected to proliferative culture for 5 consecutive passages. The cells at each passage were characterized for multipotent MSC properties such as proliferation kinetics, expression patterns of MSC surface markers and self-renewal associated markers, and chondrogenic differentiation. In results, the proliferation of the cells as determined by the cumulative population doubling level was observed at its peak on passage 3 and stopped after passage 5, whereas cell doubling time dramatically increased after passage 4. Expression of MSC surface markers (CD44, CD54, CD61, CD80, CD90 and Flk-1), molecule (HMGA2) and pluripotent markers (sox2, nanog) associated with self-renewal was negatively correlated with the number of passages. However, MSC surface marker (CD105) and pluripotent marker (Oct3/4) decreased with increasing the number of subpassage. cUC-MSCs at passage 1 to 5 underwent chondrogenesis under specific culture conditions, but percentage of chondrogenic differentiation decreased with increasing the number of subpassage. Collectively, the present study suggested that sequential subpassage could affect multipotent properties of cUC-MSCs and needs to be addressed before clinical applications.

• Journal of Chest Surgery
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• 제39권10호
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• pp.782-785
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• 2006

복부 대동맥류의 수술에 있어서 만성 폐쇄성 폐질환은 수술 사망에 유의한 영향을 미치는 위험 인자로 알려져 있다. 따라서 수술 후 호흡기 합병증을 줄이기 위해서는 강제적 기계 호흡을 줄이고 가능한 환자의 자발 호흡을 유지하는 것이 수술 결과를 향상시킬 수 있다. 본 증례에서는 복부 통증을 주소로 내원한 77세의 남자 환자로 수술 전 검사에서 약 9 cm크기의 복부 대동맥류가 발견되었으나, 심한 만성 폐쇄성 폐질환이 동반되어 수술 후 사망률이 높을 것으로 예상된 경우에서 경막외 마취등을 통해 환자의 자발 호흡을 유지한 상태로 복부 대동맥류 절제 및 인조혈관 삽입술을 시행하여 좋은 결과를 얻을 수 있었다.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.793-803
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• 2000

Procedures for treatment of molar furcation invasion defects range from open flap debridement, apically repositioned flap surgery, hemisection, tunneling or extraction, to regenerative therapies using bone grafting or guided tissue regenerative therapy, or a combination of both. Several clinical evaluations using regenerative techniques have reported the potential for osseous repair of treated furcation invasions. Regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances therefore, purpose of this study was to evaluated histologically self-curing glass-ionomer cement and light-curing glass-ionomer cement as a barrier in the treatment of a bi-furcated maxillary premolar. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on maxillary third(P3), forth(P4) and fifth(P5) premolar. 2 month later experimental group were self-curing glassionomer cement and light-curing glassionomer cement. After 4, 8 weeks, the animals were sacrificed by vascular perfusion. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. Results were as follows. 1. In all experiment group, there were not epithelial down growth and glass ionomer cement were encapsulated connective tissue. 2. In 4 weeks experiment I group slighly infiltrated inflammatory cells but not disturb the new bone or new cementum formation. 3. In 8 weeks, experiment groups I, II were encapsulated fine connective tissue. 4. Therefore glass-ionomer cement filling to the grade III maxillary furcations with multiple root anatomy and multiple furcation entrances were possible clinical methods and this technique is useful method for Maxillary furcation involvement.

• BMB Reports
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• 제55권4호
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• pp.175-180
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• 2022

Peptides are gaining substantial attention as therapeutics for human diseases. However, they have limitations such as low bioavailability and poor pharmacokinetics. Periostin, a matricellular protein, can stimulate the repair of ischemic tissues by promoting angiogenesis. We have previously reported that a novel angiogenic peptide (amino acids 142-151) is responsible for the pro-angiogenic activity of periostin. To improve the in vivo delivery efficiency of periostin peptide (PP), we used proteins self-assembled into a hollow cage-like structure as a drug delivery nanoplatform in the present study. The periostin peptide was genetically inserted into lumazine synthase (isolated from Aquifex aeolicus) consisting of 60 identical subunits with an icosahedral capsid architecture. The periostin peptide-bearing lumazine synthase protein cage nanoparticle with 60 periostin peptides multivalently displayed was expressed in Escherichia coli and purified to homogeneity. Next, we examined angiogenic activities of this periostin peptide-bearing lumazine synthase protein cage nanoparticle. AaLS-periostin peptide (AaLS-PP), but not AaLS, promoted migration, proliferation, and tube formation of human endothelial colony-forming cells in vitro. Intramuscular injection of PP and AaLS-PP increased blood perfusion and attenuated severe limb loss in the ischemic hindlimb. However, AaLS did not increase blood perfusion or alleviate tissue necrosis. Moreover, in vivo administration of AaLS-PP, but not AaLS, stimulated angiogenesis in the ischemic hindlimb. These results suggest that AaLS is a highly useful nanoplatform for delivering pro-angiogenic peptides such as PP.

• 한국간호교육학회지
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• 제14권2호
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• pp.167-175
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• 2008

Purpose: The purpose of this study was to explore the structure and characteristics of male college nursing students' personality-based career attitudes. Method: The Q-methodology was used to identify factors in male nursing students' personality-based career attitudes. A Q sample was collected from literature reviews (Kim & Kim, 2005). The subjects consisted of 30 male nursing students. Result: The results of the study show that male nursing students can be categorized into four types. The five factors extracted all had eigen values greater than 1.0 and explained approximately 50.84% of the variation in responses (32.62, 7.59, 5.70 and 4.93% respectively). The categories were labeled 'Repair intention style', 'Belief intention style', 'Stability intention style', and 'Self-regulation intention style'. Conclusion: Through a process that analyzes subjective structure, male nursing students' personality based career attitudes create occupational consciousness, professional accomplishment and professional ethics as a nursing profession. Content of curriculum and development of a reasonable and realistic course consultation program should be done.

• 품질경영학회지
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• 제21권2호
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• pp.1-16
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• 1993

Early generations of products had little to no inherent capability to test themselves. The technologies involved often required only visual inspection and limited probing to troubleshoot the system once it was turned over to maintenance personnel. However, as the complexity of military and commercial systems grew, symptoms of failure became less noticeable to the operator. Therefore, the procedure to access, inspect, repair and replace a component became complicated, the requirements for personnel skill and testing equipment increased. and it took too long of a time to maintain a system. Meanwhile, the need for availability became more mission-critical and maintenance become very expensive. The obvious solution was to design in-system circuits or devices to self-test the primary system, the Built-In-Test(BIT) was born. This approach has continued right on up through present systems and is an integral part of systems now being designed. The object of this paper is to present a state-of-the-art research for filtering out the BIT diagnosis mistakes using Bayesian analysis and develop the algorithm for Redundant systems with BIT to improve BIT diagnosis.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권3호
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• pp.224-230
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• 2016

Purpose: Military maintenance involves corrective and preventive actions carried out to keep a system in or restore it to a predetermined condition. This research develops an optimal maintenance cycle for aviation oil testing equipment with acceptable reliability level and minimum maintenance cost. Methods: The optimal maintenance policy in this research aims to satisfy the desired reliability level at the lowest cost. We assume that the failure process of equipment follows the power law non-homogeneous Poisson process model and the maintenance system is a minimal repair policy. Estimation and other statistical procedures (trend test and goodness of fit test) are given for this model. Results: With time varying failure rate, we developed reliability-based maintenance cost optimization model. This model will reduce the ownership cost through adopting a proactive reliability focused maintenance system. Conclusion: Based on the analysis, it is recommended to increase the current maintenance cycle by three times which is 0.5 year to 1.5 years. Because of the system's built-in self-checking features, it is not expected to have any problems of preventative maintenance cycle.

• Journal of Dental Anesthesia and Pain Medicine
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• 제17권1호
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• pp.13-20
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• 2017

Cleft palate is one of the most common congenital malformations of the oral and maxillofacial region, with an incidence rate of around 0.1%. Early surgical repair is the only method for treatment of a cleft lip and palate. However, because of the use of inhalation anesthesia in children and the physiological characteristics of the cleft palate itself combined with the particularities of cleft palate surgery, the incidence rate of postoperative emergence agitation (EA) in cleft palate surgery is significantly higher than in other types of interventions. The exact mechanism of EA is still unclear. Although restlessness after general anesthesia in children with cleft palate is self-limiting, its effects should be considered by clinicians. In this paper, the related literature on restlessness after surgery involving general anesthesia in recent years is summarized. This paper focuses on induction factors as well as prevention and treatment of postoperative restlessness in children with cleft palate after general anesthesia. The corresponding countermeasures to guide clinical practice are also presented in this paper.

• 한국통신학회논문지
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• 제22권10호
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• pp.2123-2135
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• 1997

고집적 SRAM을 구성하고 있는 일반적인 메모리 셀을 이용하여 저항성 단락을 MOSFET의 게이트-소오스, 게이트-드레인, 소오스-드레인에 적용시키고, 각 단자에서 발생 가능한 개방 결함을 고려하여 그 영향에 따른 메모리의 자장노드의 전압과 VDD에서의 정전류를 PSPICE 프로그램으로 분석하였다. 해석 결과를 고려하여 메모리의 기능성과 신뢰성을 향상시키기 위해 기능 테스트와 IDDQ 테스트에 동시에 적용할 수 있는 O(N)의 복잡도를 갖는 테스트 알고리즘을 제안하였다. 테스트의 질과 효율을 좀 더 향상시키기 위해 메모리에서 발생되는 고장을 검출하는 BIST 회로와 정전류의 비정상적인 전류의 흐름을 발생시키는 결함을 검출하는 BICS를 설계하였다. 또한 구현한 BIST/BICS 회로는 고장 메모리의 수리를 위해 고장 및 결함의 위치를 검출할 수 있다.