• 치과방사선
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• 제25권2호
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• pp.501-511
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• 1995

The purpose of this study was to evaluate the position and shape of mental foramen in periapical radiographs. For this study, periapical radiographs of premolar areas were obtained from the 200 adults. Accordingly, the positional and shape changes of mental foramen were evaluated. The authors obtained radiographs according to changes in radiation beam direction in periapical radiographs of premolar areas, and then evaluated the positional and shape changes of mental foramen. The following results were obtained: 1. Shapes of mental foramen were observed elliptical(34.3％), round or oval(28.0％), unidentified(25.5％) and diffuse(12.2％) type in descending order of frequency. 2. Horizontal positions of mental foramen were most frequently observed at the 2nd premolar area(55.3％), the area between the 1st premolar and 2nd premolar(39.6％), the area between the 2nd premolar and 1st molar(3.4％), the 1st premolar area(1.0％), the area between the canine and 1st premolar(0.7％) in descending order of frequency. 3. Vertical positions of mental foramen were most frequently observed at the inferior to apex(67.1％), and at apex(24.8％), overlap with apex(6.4％), superior to apex(1.7％) in descending order of frequency. 4. Shapes of mental foramen were more obviously observed at the upward 10° positioned periapical radiographs. And according to the changes of horizontal and vertical position, they were observed similar to normally positioned periapical radiographs.

• 한국항공우주학회지
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• 제39권8호
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• pp.689-701
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• 2011

본 연구에서는 착빙 환경 요소와 결빙 형상 파라미터의 관계를 자가조직도와 분산분석을 활용하여 분석하였다. 결빙 형상에 영향을 미치는 외기 조건으로 자유류 속도, 대기온도, 대기중 물방울 함유량(LWC), 액적의 평균 직경(MVD)을 선정하였다. 그리고 결빙 형상의 특징이 되는 파라미터로 최대 두께, 결빙한계(Icing limit), 결빙 진행 방향, 결빙면적을 선정하였다. 자가 조직도의 결과는 결빙형상 파라미터에 관계가 있는 외기 조건에 대한 정성적인 관계를 제시하였고 분산분석의 결과는 형상 파라미터에 대한 외기 조건의 영향력의 상대적인 크기와 순위를 정량적으로 제시하였다.

• 한국융합학회논문지
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• 제10권11호
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• pp.173-179
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• 2019

DICOM 영상은 인체의 진단과 치료에 중요한 역할을 하고 있으며 설계모델링은 목적에 따라 형상을 3차원으로 계획하는 기술이다. 본 연구는 이러한 두 가지 기술을 융합하여 외이도의 형태적 변화에 대한 횡단면, 부피, 표면적의 관계를 관찰하고자 하였다. 실험은 인체의 단면 획득 의료영상기술을 적용하여 19귀의 외이도를 추출한 3차원 형상을 스테레오리소그래피, 3-매틱(matic) 프로그램으로 센터라인 생성 및 분할 기술을 적용하였다. 그 결과 외이도의 횡단면 구조는 타원형(38.5%), 반원형(28.2%), 혼재형(17.9%), 네모형(10.2%), 주름형(5.1%)등 다양한 형태가 나타났다. 또한 외이도 길이가 길수록 위상별 횡단면 면적은 크게 나타났으며 부피와 표면적은 고막방향으로 갈수록 감소하였지만 그 감소율은 상대적으로 낮게 나타났다. 이는 외이도의 형태가 고막방향으로 갈수록 불규칙한 구조로 되어 있음을 나타냈다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제18권3호
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• pp.29-39
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• 2012

Window and shading designs have a great influence on energy consumption and daylighting in buildings. As far as energy is concerned, small window area is advantageous. But it is not good to the patient healing in hospital. So it is important to find out the optimum window shape which is favorable for both energy consumption and patient healing. In this study, annual energy consumption and daylight illumination levels were analyzed according to the window shapes and shading devices for a multi-beded patient room in hospitals. The simulations were conducted for 19 different cases by COMFEN 4.0 computer simulation program. The results of this paper are as follows. First, window to wall area ratio and shading devices have great influences on annual energy consumption. But it is a problem in that they decrease significantly daylight level in bed room. Second, considering the same energy consumption, reducing the width of window rather than the hight of window is desirable for the secure of daylight level. Third, increase of the number of horizontal shade is not desirable in south face of the building for the energy consumption and daylight level. Fourth, sun shade is not necessary in north face of the building for the energy consumption and daylight level.

• 패션비즈니스
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• 제10권5호
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• pp.105-121
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• 2006

Body measurement was first made with the subjects of 193 males in their 20s residing in the Ningbo area, Zhejiang Province in China. In this first report, lower body shapes were classified and discriminated by using anthropometric measurement indices and lower body analysis. The following sums up the research: 1. Compared with the average values of Korean males in their 20s, the Chinese subjects were characterized with thinner waist, more flat hip, and smaller midthigh. 2. The subjects of Chinese males in their 20s showed three types of lower bodies: H-Round Type (25.91%)-thick waist-abdomen, round cross-section waist-abdomen, and small waist-hip difference. A-Trapezoid Type (34.72%)-small width of omphalion waist-abdomen, average cross-section waist-abdomen, and large waist-hip difference. A-Balance Type (39.38%)-average width of omphalion waist-abdomen, flat cross-section waist-abdomen, and large waist-hip difference. 3. Seven useful variables for the categorization of the subjects' lower body types were chosen through stepwise discriminant analysis, and the hit ratio of discrimination was 96.89%.

• 음성과학
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• 제3권
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• pp.83-92
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• 1998

Vowels are classified by vocal tract shapes. These shapes form constriction points along the tract, which have an influence on such vocal tract resonance as $F_l,\;F_2,\;F_3$, and so on. This study reviews the perturbation theory of the tract and determines the corresponding formant frequencies from modified vocal tracts using vocal tract area function. Then, formant variation is observed from the theory. Finally, each set of $F_l,\;F_2,\;and\;F_3$ frequency is input to a speech synthesis software to make a vowel sound. Auditory impression of each sound without any modification of its vocal tract shape is almost the same as the corresponding phonetic symbol. Formant frequencies of $F_l,\;F_2,\;F_3$ vary according to the perturbation theory. Generally, constriction along the node causes formant values to decrease while constriction along the anti-node cause it to increase. Vocal tracts modified by more than $3\;cm^2$ change vowel qualities of /a/ and /i/ into those of f /v/ and /$\varepsilon$/, respectively. This study will be helpful in simulating sounds from modified vocal tracts before any operation. Further studies are desirable to compare vocal tract shapes of various languages and their sounds together.

• Smart Structures and Systems
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• 제23권2호
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• pp.195-205
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• 2019

An accurate non-model-based method for delamination identification of laminated composite plates is proposed in this work. A weighted mode shape damage index is formulated using squared weighted difference between a measured mode shape of a composite plate with delamination and one from a polynomial that fits the measured mode shape of the composite plate with a proper order. Weighted mode shape damage indices associated with at least two measured mode shapes of the same mode are synthesized to formulate a synthetic mode shape damage index to exclude some false positive identification results due to measurement noise and error. An auxiliary mode shape damage index is proposed to further assist delamination identification, by which some false negative identification results can be excluded and edges of a delamination area can be accurately and completely identified. Both numerical and experimental examples are presented to investigate effectiveness of the proposed method, and it is shown that edges of a delamination area in composite plates can be accurately and completely identified when measured mode shapes are contaminated by measurement noise and error. In the experimental example, identification results of a composite plate with delamination from the proposed method are validated by its C-scan image.

• 한국수학사학회지
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• 제37권3호
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• pp.59-75
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• 2024

This study aims to analyze Joseon mathematical knowledge and its application to real world. The mathematical knowledge refers to measuring the area of plane figures, known as square-shaped land(方田). Its application is land surveys(量田) conducted for taxation purposes. Specifically, this study analyzes the correlation between the related contents in representative mathematical books of the Joseon Dynasty, such as MuksaJipsanbub (17th century), Guiljib (18th century), and SanhakIbmun (18th century), and the shapes and areas of plane figures presented in GwangmuYangan (20th century). The analysis reveals both differences and similarities in the measured area between mathematical books and real world land surveys. While most results of the land survey align with the results obtained from mathematical methods, differences arise due to variations in real measurement of lengths and given conditions in the problems. Additionally, various aspects such as the focus on rectangles in land surveys, the proportionality and relativity of lengths, types of approximation, composed shapes, the purpose of problem solving, and reasoning of unspecified shapes or measures are discussed.

• 호남수학학술지
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• 제32권1호
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• pp.53-60
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• 2010

The concept of discrete curvature is a discretization of the curvature. Many literatures introduce discrete curvatures derived from arc length of circular arcs. We propose a new concept of discrete curvature of a polygon at each vertex, which is derived from area of fan shapes. We estimate the error of the discrete curvature and compare the discrete curvature with old one.

• 한국주거학회논문집
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• 제25권5호
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• pp.43-50
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• 2014

This study assesses thermal environment of detached housing area by classifying buildings types with codes based on spatial characteristics and forms of the detached housing area and applying heat island alleviation measures, especially focused on FBCs (Form-Based Codes). We analyzed shapes and materials of outdoor space with 3D-CAD, which can affect the surface temperature of the case studies, focusing on heat island alleviation measures, and performed space design by applying relevant climate factors to a simulation. As to the 3D surface temperature and HIP distribution, low-temperature distribution was shown in the case studies when we applied heat island alleviation measures. FBCs (Form- Based Codes) is being developed for the purpose of creating new urban environment. This study is significant because it pays attention to the effects of surface temperatures on accumulation of sensible heat and reviews heat island alleviation measures with outdoor space shapes/materials in order to lower surface temperatures, aiming at improved pleasantness of the detached housing area.