• 제목/요약/키워드: horizontal and vertical distances

검색결과 80건 처리시간 0.024초

Positional symmetry of porion and external auditory meatus in facial asymmetry

  • Choi, Ji Wook;Jung, Seo Yeon;Kim, Hak-Jin;Lee, Sang-Hwy
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제37권
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    • pp.33.1-33.9
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    • 2015
  • Background: The porion (Po) is used to construct the Frankfort horizontal (FH) plane for cephalometrics, and the external auditory meatus (EAM) is to transfer and mount the dental model with facebow. The classical assumption is that EAM represents Po by the parallel positioning. However, we are sometimes questioning about the possible positional disparity between Po and EAM, when the occlusal cant or facial midline is different from our clinical understandings. The purpose of this study was to evaluate the positional parallelism of Po and EAM in facial asymmetries, and also to investigate their relationship with the maxillary occlusal cant. Methods: The 67 subjects were classified into three groups. Group I had normal subjects with facial symmetry ($1.05{\pm}0.52mm$ of average chin deviation) with minimal occlusal cant (<1.5 mm). Asymmetry group II-A had no maxillary occlusal cant (average $0.60{\pm}0.36$), while asymmetry group II-B had occlusal cant (average $3.72{\pm}1.47$). The distances of bilateral Po, EAM, and mesiobuccal cusp tips of the maxillary first molars (Mx) from the horizontal orbital plane (Orb) and the coronal plane were measured on the three-dimensional computed tomographic images. Their right and left side distance discrepancies were calculated and statistically compared. Results: EAM was located 10.3 mm below and 2.3 mm anterior to Po in group I. The vertical distances from Po to EAM of both sides were significantly different in group II-B (p=0.001), while other groups were not. Interside discrepancy of the vertical distances from EAM to Mx in group II-B also showed the significant differences, as compared with those from Po to Mx and from Orb to Mx. Conclusions: The subjects with facial asymmetry and prominent maxillary occlusal cant tend to have the symmetric position of Po but asymmetric EAM. Some caution or other measures will be helpful for them to be used during the clinical procedures.

동양의 전통 족자와 현대의 디지털 세로 영상의 공간 구성 비교 연구 (A Comparative Study of Spatial Composition in East Asian Hanging Scrolls and Contemporary Digital Vertical Videos)

  • 손령;김유진
    • 문화기술의 융합
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    • 제10권3호
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    • pp.289-298
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    • 2024
  • 디지털 모바일 기술이 발전함에 따라 세로 영상은 뉴미디어 환경에서 중요한 영상 포맷으로 자리 잡았으며, 이는 기존의 가로 지향적인 영상 미학에 새로운 시각적 언어로써 도전장을 내밀었다. 이 연구는 동양 족자의 고유한 공간 구성 기법인 '삼원법', '일하양안 삼단식', '여백기법'과 '시서화 합일'과 같은 전통적 요소를 현대의 세로 영상 창작에 접목하여, 두 매체 간의 시각적 및 구조적 유사성과 차이점을 탐구한다. 이를 통해, 세로형 배치가 어떻게 화면의 깊이와 계층을 강화하고, 감정 표현을 심화시키며, 창작자에게 새로운 표현의 가능성을 열어주는지를 분석한다. 본 연구에서는 전통적인 동양 족자와 현대 디지털 환경에서 널리 사용되는 세로 영상 사이의 공간 구성 방식을 비교 분석함으로써 새로운 시각적 언어와 미학적 가치를 탐색하고자 한다.

스테레오 3mm 밀리미터파 영상을 이용한 은닉물체의 거리추정에 관한 연구 (Stereo 3 mm Millimeter Wave Imaging for Distance Estimation to Concealed Objects)

  • 염석원
    • 융합신호처리학회논문지
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    • 제18권1호
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    • pp.21-24
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    • 2017
  • 밀리미터파 영상시스템은 위험한 은닉 물체를 탐지하는 분야에 활용되고 있다. 능동형 시스템은 외부 RF 신호원이 필요하지만 수동형은 인체와 물체의 온도차에 의한 흑체복사 성질을 이용하므로 실내외에서 사용이 가능하다. 그러나 일반적으로 수동형 밀리미터파 영상은 온도분해능과 신호레벨이 낮고 잡음의 영향이 크다. 본 논문에서 은닉 물체까지의 거리 추정을 위한 수동형 스테레오 3mm 밀리미터파 영상에 관한 연구를 수행한다. 수평, 수직 편광 밀리미터파 영상시스템에서 획득한 두 쌍의 스테레오 영상을 이용하여 은닉물체를 k-means 클러스터링 알고리즘으로 몸체영역과 분할하고 물체의 중심 위치를 이용하여 거리를 추정한다. 실험에서 성공적으로 거리를 추정할 수 있음을 확인한다.

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성토폭의 확장에 의한 지중응력 결정법 연구 (Study on the Method of Determination of Vertical Stress Due to Extension of Embankment Width)

  • 이승현;김응석
    • 한국산학기술학회논문지
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    • 제16권10호
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    • pp.6846-6851
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    • 2015
  • 본 연구에서는 성토체의 확장에 의해 성토체 하부지반으로 전달되는 연직응력 증분량을 계산할 수 있는 식을 탄성론에 근거하여 유도하였다. 연직응력 증분량 산정식의 유도과정에서는 평면기점의 개념을 적용하여 유도과정을 단순화하였다. 연직응력 증분량 산정식에 의한 계산결과를 수치해석결과와 비교해 보았을 때 성토체 하부지반으로의 깊이가 커질수록 산정식과 수치해석결과 사이의 차이가 감소하였다. 수평방향 거리에 따른 연직응력 증분량을 수치해석결과와 산정식에 의한 결과를 통해 비교해 볼 때 대체적으로 산정식에 의해 예측된 연직응력 증분량이 수치해석에 의한 증분량보다 약간 커서 보수적인 결과를 보임을 알 수 있었다.

Three-dimensional analysis of the distal movement of maxillary 1st molars in patients fitted with mini-implant-aided trans-palatal arches

  • Miresmaeili, Amirfarhang;Sajedi, Ahmad;Moghimbeigi, Abbas;Farhadian, Nasrin
    • 대한치과교정학회지
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    • 제45권5호
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    • pp.236-244
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    • 2015
  • Objective: The aim of this study was to investigate three-dimensional molar displacement after distalization via miniscrews and a horizontal modification of the trans-palatal-arch (TPA). Methods: The subjects in this clinical trial were 26 Class II patients. After the preparation of a complete set of diagnostic records, miniscrews were inserted between the maxillary 2nd premolar and 1st molar on the palatal side. Elastic modules connected to the TPA exerting an average force of 150-200 g/side parallel to the occlusal plane were applied. Cone-beam computed tomography was utilized to evaluate the position of the miniscrews relative to the adjacent teeth and maxillary sinus, and the direction of force relative to molar furcation. The distances from the central point of the incisive papilla to the mesiopalatal cusps of the 1st maxillary molars and the distances between the mesiopalatal cusps of the left and right molars were measured to evaluate displacement of the maxillary molars on the horizontal plane. Interocclusal space was used to evaluate vertical changes. Results: Mean maxillary 1st molar distalization was $2.3{\pm}1.1mm$, at a rate of $0.4{\pm}0.2mm/month$, and rotation was not significant. Intermolar width increased by $2.9{\pm}1.8mm$. Molars were intruded relative to the neighboring teeth, from 0.1 to 0.8 mm. Conclusions: Distalization of molars was possible without extrusion, using the appliance investigated. The intrusive component of force reduced the rate of distal movement.

화재확산 저감을 위한 랙크 내 수평차단막 적용에 관한 연구 (Application of Horizontal Barrier on a Rack to Reduce Fire Spread)

  • 여인환;조규환
    • 한국화재소방학회논문지
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    • 제31권4호
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    • pp.71-79
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    • 2017
  • 적재밀도가 높으며 수직적인 적재형태를 가지는 랙크식 창고는 화재발생 시 그 피해가 매우 심각하다. 이에 미국, 일본에서는 자국의 랙크식 창고 실정에 맞는 In-Rack 스프링클러 및 수평차단막 등을 적용하여 화재확산을 최소화하는데 노력하고 있으나 국내의 경우, 그와 관련한 연구 및 제도가 전무한 실정이다. 이에 본 연구에서는 발화위치 및 수평차단막 설치간격에 따른 화재특성 확인을 위해 국내 랙크식 창고 실정을 반영한 표준랙크를 대상으로 축소모델 화재시험을 수행하였다. 그 결과, 수평차단막의 설치간격을 밀접하게 또는 빈번하게 할수록 약 30%씩의 수직 화재확산 억제성능이 발휘되는 것을 확인하였다. 아울러 수평차단막을 경계로 상하부의 온도를 측정한 결과, 차단막이 설치된 경우가 그렇지 않은 경우에 비해 온도분포가 약 2~4배 이상 높은 것으로 나타나 수평차단막의 설치가 In-Rack 스프링클러의 조기 작동에 도움을 줄 것으로 판단된다.

Discrepancy of the location of depression on the soft tissue and the bone in isolated zygomatic arch fracture

  • Yong Jig Lee;Dong Gil Han;Se Hun Kim;Jeong Su Shim;Sung-Eun Kim
    • 대한두개안면성형외과학회지
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    • 제24권1호
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    • pp.18-23
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    • 2023
  • Background: When performing reduction of zygomatic arch fractures, locating the inward portion of the fracture can be difficult. Therefore, this study investigated the discrepancy between the locations of the depression on the soft tissue and bone and sought to identify how to determine the inward portion of the fracture on the patient's face. Methods: We conducted a retrospective review of chart with isolated zygomatic arch fractures of type V in the Nam and Jung classification from March 2013 to February 2022. For consistent measurements, a reference point (RP), at the intersection between a vertical line passing through the end point of the root of the ear helix in the patient's side-view photograph and a transverse line passing through the longest horizontal axis of the external meatus opening, was established. We then measured the distance between the RP and the soft tissue depression in a portrait and the bone depression on a computed tomography (CT) scan. The discrepancy between these distances was quantified. Results: Among the patients with isolated zygomatic arch fractures, only those with a fully visible ear on a side-view photograph were included. Twenty-four patients met the inclusion criteria. There were four types of discrepancies in the location of the soft tissue depression compared to the bone depression: type I, forward and upward discrepancy (7.45 and 3.28 mm), type II, backward and upward (4.29 and 4.21 mm), type III, forward and downward (10.06 and 5.15 mm), and type IV, backward and downward (2.61 and 3.27 mm). Conclusion: This study showed that discrepancy between the locations of the depressions on the soft tissue and bone exists in various directions. Therefore, applying the transverse and vertical distances measured from a bone image of the CT scan onto the patient's face at the indicated RP will be helpful for predicting the reduction location.

EFFECT OF THE SHAPE OF IMPINGEMENT PLATE ON THE VAPORIZATION AND FORMATION OF FUEL MIXTURE IN IMPINGING SPRAY

  • Kang, J.J.;Kim, D.W.;Choi, G.M.;Kim, D.J.
    • International Journal of Automotive Technology
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    • 제7권5호
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    • pp.585-593
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    • 2006
  • The effect of the shape of the side wall on vaporization and fuel mixture were investigated for the impinging spray of a direct injection(DI) gasoline engine under a variety of conditions using the LIEF technique. The characteristics of the impinging spray were investigated under various configurations of piston cavities. To simulate the effect of piston cavity configurations and injection timing in an actual DI gasoline engine, the parameters were horizontal distance from the spray axis to side wall and vertical distance from nozzle tip to impingement plate. Prior to investigating the side wall effect, experiments on free and impinging sprays for flat plates were conducted and these results were compared with those of the side wall impinging spray. For each condition, the impingement plate was located at three different vertical distances(Z=46.7, 58.4, and 70 mm) below the injector tip and the rectangular side wall was installed at three different radial distances(R=15, 20, and 25 mm) from the spray axis. Radial propagation velocity from spray axis along impinging plate became higher with increasing ambient temperature. When the ambient pressure was increased, propagation speed reduced. High ambient pressures tended to prevent the impinging spray from the propagating radially and kept the fuel concentration higher near the spray axis. Regardless of ambient pressure and temperature fully developed vortices were generated near the side wall with nearly identical distributions, however there were discrepancies in the early development process. A relationship between the impingement distance(Z) and the distance from the side wall to the spray axis(R) was demonstrated in this study when R=20 and 25 mm and Z=46.7 and 58.4 mm. Fuel recirculation was achieved by adequate side wall distance. Fuel mixture stratification, an adequate piston cavity with a shorter impingement distance from the injector tip to the piston head should be required in the central direct injection system.

남한 지진의 지속시간과 H/V 비율 (The Duration and H/V ratio of the Ground Motion in Southern Korea)

  • 최호선;박창업;조남대
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2002년도 춘계 학술발표회 논문집
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    • pp.42-50
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    • 2002
  • The duration and H/V ratio(the amplitude ratio of the horizontal to vertical components) of ground motions caused by earthquakes in southern Korea are analyzed. Total 329 seismograms of horizontal component recorded at hypocentral distances of 10 to 350 km from 27 earthquakes with local magnitude 2 to 4 are used for the analysis. Simplified relation between the duration of ground motion( $T_{d}$) and the ratio($\chi$) of Arias intensity( $I_{A}$) and squared maximum acceleration($\alpha$$_{max}$$^{2}$) is determined to be $T_{d}$ = 3.423$\chi$$^2$+ 8.200$\chi$ + 0.029, which is useful for the estimation of the duration in southern Korea. There are three distinct distance ranges with different linear variations of the duration in hypocentral distance. They are distance intervals of 10~80km, 80~140km, and the distance greater than 140km. The duration in southern Korea shows clear proportionality to the local magnitude at magnitudes greater than 3.1. The value 1.37 of the H/V ratio obtained in southern Korea is similar to the value 1.4 of ENA(Eastern North America). The H/V ratio in southern Korea increases in the frequency range from 0.3 to 10Hz. The duration and H/V ratio of ground motions derived in this study could be used in the stochastic simulation of strong ground motion.ion.n.n.

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삼변측량에 의한 3차원 위치결정에 관한 연구 (A Study on the Determination of 3-Dimensional Position by Trilateration)

  • 박운용;이종출;김희규
    • 한국측량학회지
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    • 제7권1호
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    • pp.1-9
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    • 1989
  • 현재까지의 3차원 위치결정은 수평수직 조정에 의해서 분리 시행되어 오고 있는 실정이다. 본 연구에서는 단지 한 미지점에서 세 기지점에 대한 세 경사거리만을 측정하여 미지점의 3차원 좌표를 동시에 결정코자 함에 그 목적이 있다. 또한 본 연구에서는 잉여관측에 대한 조정문제를 관측방정식과 조건방정식에 의해 해결하였고, 아울러 이 두 해석기법의 특징을 고찰하였다.

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