• Smart Structures and Systems
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• 제20권3호
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• pp.385-396
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• 2017

The recent advancements in sensing technologies allow us to record measurements from target structures at multiple locations and with relatively high spatial resolution. Such measurements can be used to develop data-driven methodologies for condition assessment, control, and health monitoring of target structures. One of the state-of-the-art technologies, Fiber Optic Strain Sensors (FOSS), is developed at NASA Armstrong Flight Research Center, and is based on Fiber Bragg Grating (FBG) sensors. These strain sensors are accurate, lightweight, and can provide almost continuous strain-field measurements along the length of the fiber. The strain measurements can then be used for real-time shape-sensing and operational load-estimation of complex structural systems. While several works have demonstrated the successful implementation of FOSS on large-scale real-life aerospace structures (i.e., airplane wings), there is paucity of studies in the literature that have investigated the potential of extending the application of FOSS into civil structures (e.g., tall buildings, bridges, etc.). This work assesses the feasibility of using FOSS to predict operational loads (e.g., wind loads) on chain-like structures. A thorough investigation is performed using analytical, computational, and experimental models of a 4-story steel building test specimen, developed at the University of Southern California. This study provides guidelines on the implementation of the FOSS technology on building-like structures, addresses the associated technical challenges, and suggests potential modifications to a load-estimation algorithm, to achieve a robust methodology for predicting operational loads using strain-field measurements.

• Smart Structures and Systems
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• 제20권4호
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• pp.427-440
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• 2017

One of the suitable structural damage detection methods using vibrational characteristics are damage-index-based methods. In this study, a damage index for identifying damages in plate structures using frequency response function (FRF) data has been provided. One of the significant challenges of identifying the damages in plate structures is high number of degrees of freedom resulting in decreased damage identifying accuracy. On the other hand, FRF data are of high volume and this dramatically decreases the computing speed and increases the memory necessary to store the data, which makes the use of this method difficult. In this study, FRF data are compressed using two-dimensional principal component analysis (2D-PCA), and then converted into damage index vectors. The damage indices, each of which represents a specific condition of intact or damaged structures are stored in a database. After computing damage index of structure with unknown damage and using algorithm of lookup tables, the structural damage including the severity and location of the damage will be identified. In this study, damage detection accuracy using the proposed damage index in square-shaped structural plates with dimensions of 3, 7 and 10 meters and with boundary conditions of four simply supported edges (4S), three clamped edges (3C), and four clamped edges (4C) under various single and multiple-element damage scenarios have been studied. Furthermore, in order to model uncertainties of measurement, insensitivity of this method to noises in the data measured by applying values of 5, 10, 15 and 20 percent of normal Gaussian noise to FRF values is discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4287-4306
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• 2016

Network resilience provides an effective way to overcome the problem of network failure and is crucial to Internet protocol (IP) network management. As one of the main challenges in network resilience, recovering from link failure is important to maintain the constancy of packets being transmitted. However, existing failure recovery approaches do not handle the traffic engineering problem (e.g., tuning the routing-protocol parameters to optimize the rerouting traffic flow), which may cause serious congestions. Moreover, as the lack of QoS (quality of service) restrictions may lead to invalid rerouting traffic, the QoS requirements (e.g., bandwidth and delay) should also be taken into account when recovering the failed links. In this paper, we first develop a probabilistically correlated failure model that can accurately reflect the correlation between link failures, with which we can choose reliable backup paths (BPs). Then we construct a mathematical model for the failure recovery problem, which takes maximum rerouting traffic as the optimizing objective and the QoS requirements as the constraints. Moreover, we propose a heuristic algorithm for link failure recovery, which adopts the improved k shortest path algorithm to splice the single BP and supplies more protection resources for the links with higher priority. We also prove the correctness of the proposed algorithm. Moreover, the time and space complexity are also analyzed. Simulation results under NS2 show that the proposed algorithm improves the link failure recovery rate and increases the QoS satisfaction rate significantly.

• Archives of Plastic Surgery
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• 제37권3호
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• pp.277-280
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• 2010

Purpose: The resection of locally advanced or recurred breast cancers frequently result in large chest wall defects and it leads to a great challenges to cover. Generally simple skin grafts are not a practical option for patients because of their poor cosmetic appearance and prognosis. The latissimus dorsi and rectus abdominis musculocutaneous flap have traditionally been recommended for closure of these large defects. Though the cosmetic result of reconstruction using these flaps is often excellent, but has significant drawbacks. Therefore, we thought that chest wall reconstruction using the external oblique musculocutaneous flap can be an alternative method for extensive chest wall defect related to large, locally advanced breast carcinoma. Methods & Results: We present a case of a 50-year-old Korean female, refered to our department with a left breast tumor for 10 months. CT demonstrate a large tumor on the left anterior chest wall and multiple nodules of varying size in the cervical areas and liver. FDG-PET showed areas of hot uptake throughout the left chest wall, mediastinum and liver. Biopsy was consistent with invasive ductal carcinoma (Grade III). The initial tumor was considered inoperable, so a series of chemotherapy was initiated. Though the size of the breast mass was slightly decreased, the patient continued to suffer from purulent discharge, unpleasant odor and contact bleeding of the mass, the salvage mastectomy was performed. Conclusion: We could reconstruct $23{\times}16\;cm$ sized large chest wall defect, resulting from the resection of a locally advanced breast carcinoma, using an external oblique musculocutaneous flap successfully. Immediate postoperatively checked flap was healthy. Overall result was good without any significant complications and discharged 3 weeks after operation.

• 재활간호학회지
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• 제5권1호
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• pp.27-37
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• 2002

During acute stages of hospitalized stroke patients, family caregivers face many challenges. They often experience emotional distress, social isolation, and financial constraints. However, the burden of caregiving of stroke patients in acute stages has never been studied properly. The purpose of this study was to investigate the factors related to the caregivers' burden with acute stroke. The subjects were 123 acute stroke patients and their caregivers who were admitted to neurology and neurosurgery units at Dan Kook University Hospital in Chung-Nam area. An interview was performed with the use of standardized questionnaire which included data pertaining to the patients/caregivers characteristics, caregiver burden (Modified Zarit's Burden Scale), and social support (Personal Resource Questionnaire). Our results showed that the mean burden score was 3.11, indicating high level of burden. Among the sub-domain scores, financial burden was the highest. In univariate analysis, the factors related to caregiver burdens were: inability to communicate between patients and caregiver(p<.001); low cognitive function of the patients(p<.001); low level of ADL(p<.001); the gender of caregiver(p<.001); the current employment status of caregivers(p<.01); the presence of social support for caregiver(p<.001); and the availability of alternative caregivers(p<.001). In multiple regression analysis, social support for family caregivers (87%), low level of patient's cognition (2%), availability of 2nd caregiver (1%), and gender of caregiver (female, 0.4%) were significant explanatory factors of overall burden. The caregivers' burden in acute stages during hospitalization following stroke was high. Recognition of high levels of caregivers' burden and those relating factors affecting caregiver burden may allow us to develop different nursing strategies to unload the level of burden for caregivers in acute stages of stroke.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2006년도 제23차 정기총회 및 학술발표회
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• pp.7-16
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• 2006

Poultry products including meat and eggs constitute a major protein source in the American diet and disease - causing pathogens represent major challenges to the poultry industry. More than 95 % of pathogens enter the host through the mucosal surfaces of the respiratory, digestive and reproductive tracts and over the past few decades, the two main mechanisms used to control diseases have been the use of vaccines and antibiotics. However, in the poultry industry, there are mounting concerns over the ability of current vaccines to adequately protect against emerging hyper - virulent strains of pathogens and a lack of suitable, cost effective adjuvants. Thorough investigation of the immunogenetic responses involved in host-pathogen interactions will lead to the development of new and effective strategies for improving poultry health, food safety and the economic viability of the US poultry industry. In this paper, I describe the development of immunogenomic and proteomic tools to fundamentally determine and characterize the immunological mechanisms of the avian host to economically significant mucosal pathogens such as Eimeria. Recent completion of poultry genome sequencing and the development of several tissue-specific cDNA libraries in chickens are facilitating the rapid application of functional immunogenomics in the poultry disease research. Furthermore, research involving functional genomics, immunology and bioinformatics is providing novel insights into the processes of disease and immunity to microbial pathogens at mucosal surfaces. In this presentation, a new strategy of global gene expression using avian macrophage (AMM) to characterize the multiple pathways related to the variable immune responses of the host to Eimeria is described. This functional immunogenomics approach will increase current understanding of how mucosal immunity to infectious agents operates, and how it may be enhanced to enable the rational development of new and effective strategies against coccidiosis and other mucosal pathogens.

• 한국정보과학회논문지:정보통신
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• 제35권6호
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• pp.482-496
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• 2008

인터넷 라우터에서의 패킷 분류는 들어오는 모든 패킷에 대하여 패킷이 입력되는 속도와 같은 속도로 수행되어야 하는데, 여러 헤더 필드에 대해 다차원 검색을 수행하여야 하므로, 라우터 설계에 있어 가장 어려운 문제중의 하나이다. 계층적 패킷 분류 구조는 하나의 필드 검색이 끝날 때마다 검색 영역이 현저하게 줄어듦으로 매우 효율적이다. 그러나 계층적 구조들은 빈 노드와 역추적이라는 두가지 문제를 내재하고 있다. 본 논문에서는 두가지 문제를 동시에 해결하는 새로운 계층적 패킷분류 구조를 제안한다. 역추적 문제는 셋-프루닝 기법을 이용하여 해결하였으며, 이진 검색트리를 적용하여 빈노드를 제거하였다. 시뮬레이션 결과 제안된 알고리즘은 메모리 요구량의 증가 없이 검색 성능을 현저히 향상시킴을 확인하였다. 또한 셋-프루닝에 있어 제한된 룰의 복사를 적용하는 최적화 기법을 제안한다.

• 한국콘텐츠학회논문지
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• 제14권11호
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• pp.196-204
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• 2014

본 연구는 지역아동센터에서 근무하는 사회복지사의 전문성 인식이 조직헌신에 미치는 영향을 실증적으로 분석하고자 하였다. 연구대상은 전라남도 소재의 지역아동센터에서 근무하는 사회복지사를 대상으로 설문조사를 실시하였으며, 회수된 설문지 중 결측값을 제외한 286부를 분석자료로 활용하였다. 분석결과, 전문성 인식은 중간 점수 이상의 수준을 보였으며, 서비스에 대한 신념이 가장 높게 나타났다. 전문성 인식과 조직헌신 간에는 정(+)의 상관관계가 있는 것으로 나타났으며, 특히 직업에 대한 소명의식과 조직헌신 간의 상관관계가 가장 높은 것으로 나타났다. 다중회귀분석 결과, 전문성 인식의 각 하위변인인 직업에 대한 소명의식, 전문조직의 활용이 조직헌신에 영향을 미치는 것으로 나타났으며, 직업에 대한 소명의식이 가장 큰 영향을 미치는 것으로 나타났다. 이와 같은 분석결과를 바탕으로 지역아동센터 사회복지사의 전문성 인식 및 조직헌신의 향상 방안과 후속연구의 과제를 제언하였다.

• 한국학교수학회논문집
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• 제15권3호
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• pp.467-486
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• 2012

본 연구는 새터민 청소년들의 수학학습 적응 실태를 파악하고 수학학습 적응에 영향을 미치는 요인들을 분석함으로써 수학학습 적응력 신장을 위한 개선방향을 찾으려는 데 그 목적이 있다. 이를 위해 새터민 대안학교에 재학 중인 새터민 학생 43명을 대상으로 12개월 동안의 참여관찰과 수학학습 적응에 관한 설문조사를 실시하였다. 새터민 청소년들은 탈북 과정 중에서 제대로 제도화된 교육과정을 받지 못함에 따라 기초 수리능력의 부족과 낮은 학력수준으로 인한 인지적 요인뿐 아니라 수학교과에 대한 자아개념, 수학교과에 대한 학습 습관, 수학불안, 수학교과 인식 등의 정의적 영역, 그리고 수업 변인 등 환경적 영역의 요인들이 수학학습 적응에 있어서 다각적으로 영향을 미침을 알 수 있었다.

• 만화애니메이션 연구
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• 통권14호
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• pp.15-35
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• 2008

이글은 만화교육에서 인문학적 관점이 강조된 만화읽기와 토론의 의미를 여러 각도에서 살펴봄으로써 그 필요성을 강조하는 연구이다. 서론에선 먼저 기왕의 만화교육이 기능교육에 치우쳐 만화가 사람에게 갖는 의미작용에 대한 연구가 소홀히 함으로써 만화산업의 흐름에 적절히 대응하지 못하고 있다고 문제를 제기하면서, 문화적 측면과 학문적 측면이 보완된 만화교육의 필요성과 함께 주목해야할 만화교육방법으로 만화읽기와 토론을 제시한다. 본론에선 만화읽기와 토론이 강조될 이유로 여섯 가지 범주에서 문화적 의미와 학문적 의미를 짚어보았다. 구체적으론 만화읽기와 만화창작의 상호연관성, 만화에 대한 사회적 편견 극복과제, 만화의 미적특성에 대한 연구, 문화민주화정책과 만화교육의 역할, 한국사회에서 '탈식민'이란 극복과제, '대중성'확보의 내용적 시각정립 등이다.