• 한국항행학회논문지
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• 제15권6호
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• pp.1008-1014
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• 2011

본 논문에서는 WLAN 대역과 WiMax 대역에서 통신을 가능하게 하기 위한 다중대역 프랙탈 마이크로스트립 패치 안테나를 설계 및 제작하였다. 제안된 안테나는 다중공진을 위해 공진주파수, 임피던스정합, 극성 및 방사패턴을 훌륭히 제어할 수 있으며 다중 독립 주파수를 만족시키기 위한 세 개의 반원의 프랙탈 패치를 삽입하였다. 제안된 구조는 반원의 프랙탈 구조가 연속적으로 이루어져 있는 형태의 안테나로써 하나의 반원이 하나의 대역을 나타내고 있다.

• 한국전자파학회논문지
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• 제16권9호
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• pp.932-940
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• 2005

본 논문에서는 UWB 통신 시스템에서 사용될 수 있는 CPW 급전 구조를 이용한 평면형 반원 형태의 UWB 안테나를 설계, 제작 및 측정하였다. UWB 통신 주파수 대역(3.1 GHz${\~}$10.6 GHz) 내에 IEEE 802.1la(5.15 GHz${\~}$5.825GHz) WLAN 대역이 포함되어 있어 상호 간섭 문제가 발생할 수 있기 때문에 이 주파수 대역을 차단시킬 필요가 있다. 따라서 본 논문에서는 노치 기능을 갖는 세 종류의 rectangular 슬롯, hat-shaped 슬롯, circle- shaped 슬롯 UWB 안테나를 제안하였다. 제안한 안테나는 슬롯의 길이와 폭을 변화시켜 주파수 조정이 가능하다. 측정결과, IEEE 802.1la WLAN 대역을 제외한 나머지 대역에서는 무지향성을 갖는 평탄한 이득을 얻었으며, 시뮬레이션 결과도 잘 일치함을 확인하였다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.205-210
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• 2005

In this paper, a planar half-circle shape ultra-wideband(UWB) antenna fed by CPW is designed, fabricated and measured for UWB communications. Within the UWB band(3.1 GHz $\sim$ 10.6 GHz), 5.15 GHz $\sim$ 5.825 GHz frequency band is used by IEEE 802.lla WLAN applications. It may be necessary to notch out this band to avoid interference with IEEE 802.lla WLAN. Therefore, we have proposed three kinds of UWB antennas having a notch function, such as a rectangular slot, a hat-shaped slot, a circle-shaped slot. The notch frequency of the proposed antenna can be adjusted by controlling the slot length or slot width. From the measured results, the proposed antennas show a good gain flatness except the IEEE 802.lla WLAN frequency band and have a reasonable agreement with simulated results.

• 건축역사연구
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• 제17권2호
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• pp.47-66
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• 2008

This research was to analyze the border signal-fire which is the main facility of military protective duty for safety of sea side in chosun dynasty. The results of this research were described separately as follows. 1. Five types of site plan of signal-fire were observed, which is circle, half-circle, oval, round-rectangular. The majorities were circle type in eastern area. 2. Plan configuration of signal-fire stand which is separated with circle, rectangular type roughly was constructed with circle type generally. The height of signal-fire stand was about $2{\sim}3m$. The diameter of signal-fire stand was $8{\sim}10m$. Building base that protect ground moisture and infilteration of rainfall was found in 9 border singal-fire, the height of it was about $0.3m{\sim}2.5m$. 3. Trench was mainly circle type and average width was $3{\sim}4m$. However the depth was almost observed as 1m, originally, it was estimated it has more depth. 4. The height of protective wall remained until present was about 1m, the depth was about average 2.5m. 5. The storage of border signal-fire has rectangular dimension, several types of $1.8{\times}1.2m{\sim}5.7{\times}4.4m$, square(間) of $1{\times}1{\sim}2{\times}1$. The building material was stone and located below or near the signal-fire stand.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2003년도 추계학술대회 논문집
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• pp.55-58
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• 2003

In this paper the numerical method with a zonal embedded grid system for an incompressible flow within a circular container is presented. The algorithm is validated by its application to some typical flow models including the spin-up flow inside a half-circle geometry.

• 대한수학회논문집
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• 제36권4호
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• pp.829-833
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• 2021

We investigate the Möbius transformation action of PSL(2, ℝ) on the set of mutually distinct ordered triple points of ℝ ∪ {∞}.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.535-538
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• 2005

The purpose of this work is to study a process organization on space cognition by visio-auditory stimulation. We develop the system of visuo-auditory stimulation and Humans responses measurement to observe the relationship between the sensory and the motor system fur the localization of visual and auditory target direction in the space. The experiments is performed in a soundproof chamber, 2163 red, green and yellow LED(Luminescent Diode, Brightness: $20cd/m^2$ 1 degree apart each other)arrayed in front of half-circle panel were used and 57 Speaker(5 degree apart each other) arrayed in the hidden of half-circle panel. Physiological parameters such as EOG (Electro-Oculography), head movement and their synergic control are measured by BIOPAC system and Optotrak Certus. This result shows that the response latency time of the perception motion in the center is laster than the periphery of panel. These results can be used in the study of characterizing the spatial cognition.

• 수산해양기술연구
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• 제31권1호
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• pp.84-92
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• 1995

군산대학교 실습선 해림 3호의 조종성능을 파악하기 n이하여 GPS 보다 그 측립정도가 더 높은 DGPS를 이용하여 종회권 측정을 행하고, 이를 재래식 측정방법인 부표방입반법과 비교 검토하였으며, 그 결과를 요약하면 다음과 같다. 1. DGPS에 의한 선회권측정의 정도를 파악하기 위하여 육상에서 50m의 선회시험을 행한 결과 측위오차는 1.5m 이내 였다. 2. DGPS에 의한 선회권측정은 속력별, 타각별, 좌우선회별로 각각 그 특성이 잘 나타낼 수 있도록 정확하게 측정 할 수 있었다. 3. 부표방위반법에 의한 선회권측정은 타각을 크게 하여 그 선회권이 작을 때는 DGPS의 것과 같이 비교적 정확하게 측정할 수 있으나, 타각을 작게하여 선회권이 클 때는 방위오차가 크기 때문에 정확하게 측정할 수 없었다. 4. DGPS에 의한 해림 3호의 선회경(DT)은 타각 35。~5。일 때, 미속에서는 선박의 수선간장 (Lpp)상의 2.6~15.0배, 반속에서는 2.8~16.6배, 전속에서는 3.1~17.4배로 나타났었고, 부표방위반법에 의한 선회경은 각각 2.4~9.5배, 2.6~9.6배, 3.2~12.2배로 나타났었다

• 한국의류산업학회지
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• 제6권1호
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• pp.17-22
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• 2004

The purpose of this study was to obtain the basic element of patterns, which is the motif, from the existing art works and use it to create and simulate a variety of patterns to show the practical use of the computer. Natural dyed works of geometric shapes like squares and 1/4 of circles, each dyed with a different natural dyes, were produced and motifs were extracted. Then using the 4D box in Adobe Photoshop v.6.0, the developing pattern change and simulation effects when using different patterns and different repetition settings were examined. Observations were made as the motifs were replicated. Different patterns like a diagonal line, a square and a circle appeared. In order to find out the effects according to the changes, the motifs from work's square portions, circle centre, and the composition of eight motifs were extracted and used. The repeated patterns according to the extracted motifs simply showed that in the case of just repeating and arranging, square patterns appeared. By replicating and arranging, the motif and the allophone were matched and patterns with regular lines were formed, like a twill, pointed twill line. By setting the direction to Y and X in the repetition methodes, a typical half-drop arrangement or a brick pattern arrangement were formed according to 1/4, 2/4, 3/4, 1/3, or 2/3 in changes. Also the steepness of the slope changes quickly or in turn slowly as the rhombus shape appears. However in the case of a composed motif, an ogee pattern appeared. Lastly, by 3-D mapping patterns like a slant line, pointed twill patterns, diamond patterns, and the repeat patterns of a motif with a circle and a line combined, and a circle motif, an optical illusion could be observed.

• Clinics in Shoulder and Elbow
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• 제22권4호
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• pp.216-219
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• 2019

Background: Progression of the tear size and erosion of the greater tuberosity (femoralization) in the supraspinatus tear makes it difficult to repair or increases the risk of a re-tear. This study examined the proximal articular surface and greater tuberosity of the humeral head in plain radiography. Methods: Two-hundred forty-seven cases, whose anteroposterior (AP) radiographs were taken correctly, were included from 288 cases, in whom the status of the supraspinatus had been confirmed by surgery. After downloading the plain AP radiograph as DICOM, the radius of the circle apposed at the superior half of the articular surface of the head, and the distance between the circle and the farthest point of the greater tuberosity ('height' of the greater tuberosity) were calculated using the software (TechHime, Korea). MRI checked the number of torn tendons and degree of muscular atrophy. Results: The following were encountered: 93 intact supraspinatus, 50 partial-thickness tears, and 104 full-thickness tears. In the analysis using the 93 intact cases, the average radius of the rotation center was 25.3 mm in male and 22.3 mm in female. The average height of the greater tuberosity from the circle with the same rotation center was 4.3 mm in male and 4.2 mm in female with no statistical significance. The correlation between the reparability of supraspinatus and height of the greater tuberosity, fatty infiltration, and muscular atrophy was confirmed. Conclusions: The height of the greater tuberosity from the circle with the same rotation center was 4.3 mm in male and 4.2 mm in female. This height was strongly correlated with muscular atrophy and fatty infiltration of the supraspinatus tendon.