• 한국수학교육학회지시리즈A:수학교육
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• 제48권3호
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• pp.287-302
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• 2009

This study investigated how 5th grade students found and understood triangle congruence conditions (SSS, SAS, ASA). In particular, this study focused on children's processes of discovering triangle congruence conditions and the obstacles which they encountered in the process of making sense of these conditions. Our data indicates that inquiring the cases in which less than three factors of triangle are given is helpful for children to guess triangle congruence conditions and understand the minimal characteristic of these conditions. And the degree of difficulty of discovering each congruence condition is different. Children discovered SAS condition and ASA condition easily, but it was hard for them to discover and understand that SSS was also a triangle congruence condition because they connected the length of a given side with the use of a scaled ruler not a compass.

• Imaging Science in Dentistry
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• 제50권4호
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• pp.365-371
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• 2020

While silent sinus syndrome (SSS) is familiar to otolaryngologists and ophthalmologists, it is a rare clinical entity in dentistry and is likely to be underdiagnosed due to dentists' lack of awareness of this condition. SSS presents a diagnostic challenge to dentists, as patients typically have no history of trauma or sinusitis. The characteristic feature of SSS is a gradual retreat of the maxillary sinus walls, resulting in enophthalmos and hypoglobus. Multidetector (multislice) computed tomography is the imaging modality of choice for SSS and other paranasal sinus diseases. Cone-beam computed tomography promises to be an alternative low-dose imaging modality. This report describes 3 cases of SSS in adults, who had no identified clinical symptoms except diminutive and opacified maxillary sinuses, as well as the inward bowing of the sinus walls as noted on cone-beam computed tomographic imaging.

• Smart Structures and Systems
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• 제15권3호
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• pp.577-592
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• 2015

Damage quantification is a major goal of the SHM community. Methodologies to introduce a quantity for actual condition of a structure into the assessment process are desired. The idea that the condition of a structure is represented in the character of its dynamic response is fully accepted by the SHM community. The VCLIFE methodology quantifies condition analyzing input from monitoring.

• Neonatal Medicine
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• 제18권2호
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• pp.395-398
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• 2011

굴기능부전증후군은 매우 드물지만 신생아에서도 발생할 수 있으며 소아 환자의 경우 대부분 선천심장병이 있거나 심장수술 후에 발생한다. 그러나 이와 같은 심질환의 선행 요인이 없는 신생아에서도 발생할 수 있기 때문에 이에 대한 인지가 필요하다. 굴기능부전증후군은 대부분 특발성으로 발생하며 증상도 다양하고 24시간 심전도 검사상에서도 다양한 형태로 관찰된다. 본 증례에서는 초극소저체중출생아에서 선천심장병 없이 발생한 굴기능부전증후군에 대해 보고하였다. 환아는 심전도상 굴느린맥과 함께 심방세동이 동반된 느린맥과 빠른맥이 반복되어 관찰되었으며 무호흡, 산소포화도의 저하, 청색증의 징후를 나타냈다. 증상이 있는 굴기능부전증후군의 경우 대부분 심장박동조율기의 삽입이 필요하나 본 환아는 당시 체중 750 g으로 심장박동조율기의 삽입에 실패하여 약물 치료를 시작하였다. Isoproterenol과 atropine으로 치료하면서 환아의 체중이 1,500 g을 넘어서자 증상과 심전도상의 호전을 보였다. 향후 본 환아에서처럼 심장박동조율기의 삽입이 어려운 소아 환자의 경우에 대한 치료 체계에 대해 많은 연구가 필요하다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권2호
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• pp.155-159
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• 2020

Chronic maxillary atelectasis (CMA) is a progressive alteration in the volume of the maxillary sinuses that may result in facial asymmetry. CMA in asymptomatic patients is known as silent sinus syndrome (SSS) and is a rare entity, especially in pediatric patients. This study reports a case of SSS in a pediatric patient who received an early diagnosis through cone-beam computed tomography (CBCT). An asymptomatic 12-year-old female patient in orthodontic treatment presented with opacification of the left maxillary sinus on a panoramic radiograph. Clinically, the patient had discrete hypoglobus and enophthalmos. CBCT and nasal video-endoscopy revealed ostiomeatal obstruction with bone deformity, leading to diagnosis of SSS. Endonasal endoscopic maxillary sinusotomy was performed. Two years later, the patient remained asymptomatic, and a second CBCT exam confirmed a stable condition. This case highlights the role of optimal radiographic interpretation for early diagnosis of maxillofacial alterations in pediatric patients.

• Smart Structures and Systems
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• 제19권2호
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• pp.203-211
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• 2017

This paper provides a numerical solution for multiple confocal elliptic dissimilar cylinders. In the problem, the inner elliptic notch is under the traction free condition. The medium is composed of many confocal elliptic dissimilar cylinders. The transfer matrix method is used to study the continuity condition for the stress and displacement along the interfaces. Two cases, or the infinite matrix case and the finite matrix case, are studied in this paper. In the former case, the remote tension is applied in y- direction. In the latter case, the normal loading is applied along the exterior elliptic contour. For two cases, several numerical results are provided.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.160-161
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• 2005

It is important to manage artificial fish reefs with installation for restoration. The instruments of survey for artificial reefs condition(location, amount etc.) is Side Scan Sonar and Multi-beam sonar. The efficient and economic survey of the artificial reefs facility is the complete survey of the SSS(Side Scan Sonar) in all area first and then the survey of the artificial reefs by MBES(Multi Beam Echo Sounder) in the finding area.

• Smart Structures and Systems
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• 제15권3호
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• pp.751-767
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• 2015

A new procedure is proposed for assessing probabilistic condition of structures considering effect of measured data uncertainty. In this procedure, multiple Finite Element (FE) models are identified by using weighting vectors that represent the uncertainty conditions of measured data. The distribution of structural parameters is analysed using a Principal Component Analysis (PCA) in relation to uncertainty conditions, and the identified models are classified into groups according to their similarity by using a K-means method. The condition of a structure is then assessed probabilistically using FE models in the classified groups, each of which represents specific uncertainty condition of measured data. Yeondae bridge, a steel-box girder expressway bridge in Korea, is used as an illustrative example. Probabilistic condition of the bridge is evaluated by the distribution of load rating factors obtained using multiple FE models. The numerical example shows that the proposed method can quantify uncertainty of measured data and subsequently evaluate efficiently the probabilistic condition of bridges.

• 대한수학교육학회지:수학교육학연구
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• 제15권2호
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• pp.131-145
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• 2005

이 논문은 중고등학교 학생들과 예비수학교사를 대상으로 삼각형의 결정조건과 합동조건에 대한 이해의 양상의 일단을 조사하고, 삼각형의 결정조건과 합동조건에 대해 교수학적으로 분석한 것이다. 연구 결과의 일부를 제시하면 다음과 같다. 첫째, 삼각형의 6요소 구하기 학습 지도시 중학교에서 배운 삼각형의 결정조건이 지닌 의미를 재음미할 기회를 제공해야 한다. 둘째, 무엇을 삼각형의 결정조건으로 볼 것인가는 결정조건을 탐구하는 맥락에 따라 달리 판단될 수 있는 문제이다. 셋째, 삼각형의 결정조건이 지닌 최소필수성을 인식할 수 있게 하는 교재 구성과 학습 지도가 필요하다. 넷째, 합동에서 '대응'의 중요성을 인식하게 하는 학습 지도가 필요하며, 삼각형의 합동조건에서 '대응하는' 이라는 표현이 지닌 문제점을 해소하는 방안을 모색할 필요가 있다.

• Smart Structures and Systems
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• 제22권2호
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• pp.231-237
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• 2018

A significant data problem is encountered with condition monitoring because the sensors need to measure vibration data at a continuous and sometimes high sampling rate. In this study, compressive sensing approaches for condition monitoring are proposed to demonstrate their efficiency in handling a large amount of data and to improve the damage detection capability of the current condition monitoring process. Compressive sensing is a novel sensing/sampling paradigm that takes much fewer data than traditional data sampling methods. This sensing paradigm is applied to condition monitoring with an improved machine learning algorithm in this study. For the experiments, a built-in rotating system was used, and all data were compressively sampled to obtain compressed data. The optimal signal features were then selected without the signal reconstruction process. For damage classification, we used the Variance Considered Machine, utilizing only the compressed data. The experimental results show that the proposed compressive sensing method could effectively improve the data processing speed and the accuracy of condition monitoring of rotating systems.