• 지구물리와물리탐사
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• 제7권4호
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• pp.245-250
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• 2004

단일 채널 해양 탄성파탐사 자료의 2차원 탄성파 단면도에 수평거리 보정을 적용하여 탄성파 단면도의 수평축을 거리 단위로 표현하였다. 수평축을 거리 단위로 표시함으로써 탐사선의 운항 속력이 변할 경우 나타나는 수평 거리 왜곡 현상을 상당히 해소할 수 있었다. 수평거리 보정을 위하여 탄성파 자료의 각 트레이스에 저장된 GPS 위치 정보와 자료 취합 윈도우를 이용하였다. 자료 취합 윈도우의 최소 길이는 탐사선의 속력과 발파 간격에 의해 결정하였으며, 최대 길이는 1차 프레넬대 반경을 이용하여 결정하였다. 자료 취합 윈도우의 길이를 결정함에 있어 수평 해상도와 중합의 효과를 동시에 고려하였다. 수평거리 보정 과정을 적용하여 실제 지층구조와 유사하다고 생각되는 2차원 탄성파 단면도를 작성할 수 있었다.

• Imaging Science in Dentistry
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• 제46권2호
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• pp.77-85
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• 2016

Purpose: To analyze the relative position of the mandibular foramina (MnFs) in patients diagnosed with skeletal class III malocclusion. Materials and Methods: Computed tomography (CT) images were collected from 85 patients. The vertical lengths of each anatomic point from the five horizontal planes passing through the MnF were measured at the coronoid process, sigmoid notch, condyle, and the gonion. The distance from the anterior ramus point to the posterior ramus point on the five horizontal planes was designated the anteroposterior horizontal distance of the ramus for each plane. The perpendicular distance from each anterior ramus point to each vertical plane through the MnF was designated the horizontal distance from the anterior ramus to the MnF. The horizontal and vertical positions were examined by regression analysis. Results: Regression analysis showed the heights of the coronoid process, sigmoid notch, and condyle for the five horizontal planes were significantly related to the height of the MnF, with the highest significance associated with the MnF-mandibular plane (coefficients of determination ($R^2$): 0.424, 0.597, and 0.604, respectively). The horizontal anteroposterior length of the ramus and the distance from the anterior ramus point to the MnF were significant by regression analysis. Conclusion: The relative position of the MnF was significantly related to the vertical heights of the sigmoid notch, coronoid process, and condyle as well as to the horizontal anteroposterior length of the ascending ramus. These findings should be clinically useful for patients with skeletal class III mandibular prognathism.

• 한국안광학회지
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• 제9권2호
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• pp.251-255
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• 2004

만20세에서 30세사이의 남녀 60명(120안)을 대상으로 자각적 굴절검사를 실시하여 원거리 완전 교정된 상태에서 프리즘 분리법을 이용하여 원거리&근거리 수평사위를 측정하였다. 총 120안중 근시안 64안(53%), 정시안 56(47%)이었다. 원거리 수평사위는 외사위 24명(40%), 내사위 24명(40%), 정위 12명(20%)이었다. 근거리 수평사위는 외사위 39명(65%), 내사위 14명(23.3%), 정위 7명(11.7%)이었다.

• Journal of information and communication convergence engineering
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• 제10권2호
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• pp.181-186
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• 2012

Telematics services include automatic location tracking for emergency rescue, which is available for use in case of a car accident due to falling off roadways. This paper presents a simulation study on how far a car will fall before it hits the ground if it drops off of a roadway due to an accident or a natural disaster. The greatest horizontal distance the falling car can travel is presented in this paper, based on the assumption that air resistance as well as the direction and degree of acceleration due to gravity is negligible. This paper also presents the depth of the dent caused by the car sinking into the ground, the time it took for the car to fall free, and the velocity at which it travelled and horizontal distance it traveled. In this paper, the damage done to cars that crash into the ground and the dangers thereof are graphically represented.

• Geomechanics and Engineering
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• 제13권4호
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• pp.701-714
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• 2017

The effect of nearby cohesionless sloping ground on the uplift capacity of horizontal strip plate anchor embedded in sand deposit with horizontal ground surface has been studied numerically. The numerical analysis has been carried out by using the lower bound theorem of limit analysis with finite elements and linear optimization. The results have been presented in the form of non-dimensional uplift capacity factor of anchor plate by changing its distance from the slope crest for different slope angles, embedment ratios and angles of soil internal friction. It has been found that the decrease in horizontal distance between the edge of the anchor plate and the slope crest causes a continuous decrease in uplift capacity of anchor plate. The optimum distance is that distance between slope crest and anchor plate below which uplift capacity of an anchor plate has been found to decrease with a decrease in normalized crest distance from the anchor plate in presence of nearby sloping ground. The normalized optimum distance between the slope crest and the anchor plate has been found to increase with an increase in slope angle, embedment ratio and soil internal friction angle.

• 대한안전경영과학회지
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• 제16권4호
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• pp.371-378
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• 2014

Manual materials handling tasks are the main risk factors for the work-related musculoskeletal disorders. Many assistant tools for manual materials handling are being used in various kind of industries. One of them is a 4-wheeled cart which is widely used in manufacturing factories, hospitals, etc. The major force required to control the 4-wheeled cart is pushing and pulling. There are two types of handles being used for the 4-wheeled cart : vertical type (two vertical handles), and horizontal type (one horizontal handle). This study tried to investigate the pushing forces and subjective discomforts (hand/writst, shoulder, low back, and overall) of the two handle types with different handle height and distance conditions. Twelve healthy male students (mean age = 23.4 years) participated in the experiment. The independent variables were handle angle (horizontal, vertical), handle height (low, medium, high), and handle distance (narrow, medium, wide). The full factorial design was used for the experiment and the maximum pushing forces were measured in 18 different conditions ($2{\times}3{\times}3$). Analysis of variance (ANOVA) procedure was conducted to test the effects of the independent variables on the pushing force and discomfort levels. Handle height and angle were found to be the critical design factors that affect the maximal pushing forces and subjective discomfort. In the middle height, subjects exerted higher pushing forces, and experience lower discomfort levels compared to the high, and low height. There was no statistical influence of the handle distance to the pushing forces and subjective discomfort levels. It was found out that the effects of the handle angle (horizontal and vertical) on both pushing force and subjective discomfort were statistically significant (p < 0.05). The vertical handle revealed higher pushing force and lower discomfort level than the horizontal handle. The reason for that was thought to be the different postures of the hand when grasping the handles. The horizontal handle induced pronaton of the hand and made hand posture more deviated from the neutral position.

• Asian Journal of Atmospheric Environment
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• 제9권1호
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• pp.22-30
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• 2015

This study evaluated road shape and roadside barrier impact on near-road air pollution dispersion using FLUENT computational fluid dynamics (CFD) model. Simulated road shapes are three types, namely at-grade, depressed, and filled road. The realizable k-${\varepsilon}$ model in FLUENT CFD code was used to simulate the flow and dispersion around road. The selected concentration profile results were compared with the wind tunnel experiments. The overall concentration profile results show good agreement with the wind tunnel results. The results showed that noise barriers, which positioned around the at-grade road, decrease the horizontal impact distance (In this study, the impact distance was defined as the distance from road surface origin coordinate to the position whose mass fraction is 0.1.) lower 0.33~0.65 times and change the vertical air pollution impact distance larger 2.0~2.27 times than those of no barrier case. In case of filled road, noise barriers decrease the horizontal impact distance lower 0.24~0.65 times and change the vertical air pollution impact distance larger 3.33~3.55 times than those of no barrier case. The depressed road increase 1.53~1.68 times the vertical air pollution impact distance. It contributes the decrease of horizontal air pollution impact distance 0.32~0.60 times compare with no barrier case.

• 치과방사선
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• 제23권2호
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• pp.207-211
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• 1993

The auther has evaluated the panoramic image of the mandibular condyle according to its horizontal codylar angle(0°, 10°, 20°, 30°, 40°) and intercondylar distance( 9.5, 11.0, 12.5, 14.0㎝). The Results were as follows: 1. In all horizontal condylar angle, the farther the intercondylar distance was, the smaller the horizontal length in radiogram was. 2. The increased the horizontal condylar angle was, the longer in horizontal direction and the shorter in vertical direction the image of superior condylar surface was. 3. In case of large horizontal condylar angle, the real mesial surface of condyle was projected to the posterior surface on radiograph.

• 한국농공학회지
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• 제31권2호
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• pp.104-115
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• 1989

In an effort to clarify the wetted patterns of sandy loam soil under trickle irrigation conditions, the distance of wetted zone, infiltration capacity and soil wetted patterns, etc. were measured by gypsum block as soil moisture sensor located every 5 cm vertically and horizontaly in the soil bin under the such conditions as a). irrigation rates set to 2, 4, 6, 8 liters per hour b). total amount of water applied fixed to 14.62 liters per soil bin c) the hearing force of soil measured by plate penetrometer ranging from 1.04 to 1.22kg/cm$_2$ The results can be summarized as follows ; 1. The wetted distance in horizontal direction(H), the wetted distance in vertical direction(D), the horizontal infiltration capacity (iH) and the vertical infiltration capacity(in)could by explained as a function of time t. 2. The horizontal wetted distance (H) is explained by an exponetial function H= a$.$ t where b was found ranging from 021 to 026 under surface trickle irrigation, which was considered a lotlower than the classical value of 0.5 and these measurements were indifferent to the increasing irrigation rates. 3. As for the surface trickle irrigation where horizontal infiltration capacity(iH) is explained as iH = A $.$ t h, the coefficient A increases with respect to irrigation rates within the limits of 0.89~1.34. 4. In terms of surface trickle irrigation of the ratio of Dm Which is maximum vertical wetted distance to Hm, which is maximum horizontal wetted distance, found to be within range of 1.0 to 1.21. It was also noted that the value of Dm decreses when irrigation rates increases while the value of Hm changes the opposite direction. 5. The optimum location of sensors from emitter for surface trickle irrigation should he inside of hemisphere whose lateral radius is 28~30cm long and vertical radius is 10~12cm long. The distance between emitters should be within 60cm long. 6. In the study of vertical wetted distance( D) where D= a $.$ tb, the exponential coefficient b ranged from 0.61 to 0.75 in surface trickle irrigation, and from 0A9 to 0.68 for subsurface trickle irrigation. These measurements showed an increasing tendency to with respect to irrigation rates. 7. In case of vertical infiltration capacity( in), where iD= A $.$ t 1-h, the coefficient A for surface trickle irrigation found to be within range of 0.16 to 0.19 and did not show any relationships with varying degree of irrigation rates. However, the coefficient was varying from 0.09 to 0.22 and showed a tendency to increase vis-a-vis irrigation rates for subsurface trickle irrigation, in contrast. 8. In the observation of subsurface trickle irrigation, it was found that Dm/Hm ratio was within 1.52 to 1.91 and showed a decreasing tendency with respect to increasing rates of irrigation. 9. The location of sensors for subsurface trickle irrigation follows same pattern as above, with vertical distance from emitter being 10~17cm long and horizontal 22~25cm long. The location of emitter should be 50 cm. 10.The relationship between VS which is the volume of wetted soil and Q which is the total amount of water when soil is reached field capacity could be explained as VS= 2.914Q0.91and the irrigation rates showed no impacts on the above relationship.

• 조명전기설비학회논문지
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• 제27권4호
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• pp.73-80
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• 2013

Breakdown characteristics of air in the vertical arrangement of line conductor and plane electrode in case of combustion flame on the plane electrode are examined by the application of AC. and DC voltages to the gap. In order to investigate the effect of paraffin flame on the breakdown characteristics of air, flashover voltages are measured according to the variation of the gap length and the horizontal distance between the flame and the line conductor. As the result of the experiment, flashover voltages are substantially lowered down to 29.8% in case of the AC voltage, and 16.1% in case of the negative DC voltage, when in the presence of the flame. from 100% when in the absence of flame. Flashover voltages of air in the range of smaller than 3㎝ at the horizontal distance are increased in the proportion of the gap length and the horizontal distance in case of both AC and negative DC voltages. But before the flashover occurs, the flame is extinguished by such corona wind that is produced from the line conductor when the gap length and the horizontal distance reach to a certain degree. The effect of relative air density and the phenomenon of thermal ionization are analysed as the reduction factors of flashover voltages, due to high temperature of the flame.