• 한국지반환경공학회 논문집
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• 제17권12호
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• pp.27-34
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• 2016

많은 급경사 보강성토 또는 보강토벽 구조물의 장점은 토지 이용의 효율성이나 현장에서 사용하는 공법 비용들의 경제성 때문에 점점 높아지고 있다. 보강토체의 인장력을 이용한 기존 보강토옹벽 공법들은 자연사면의 경사보다 훨씬 급경사에 설계할 수 있도록 발전해 왔다. 지반개량재를 사용하여 급경사의 전면벽체를 보강한 방법은 최근에 상당히 효율적인 토지 사용을 위해 많이 공사되고 있다. 본 연구는 지오그리드를 매설한 뒷채움 흙과 지반개량재로 보강한 전면벽체로 구성한 복합보강토 옹벽을 소개한다. 급경사를 이루고 있는 전면벽체의 안정성을 위해 현장시공 계측과 수치해석으로 비교 검증과 분석하였다. 또한 현장계측은 14개월 동안의 변위측정으로 안정성에 대한 관측으로 수치해석과 비교하였다. 현장시험 시공에서 일반적인 수직하중에 의한 수평거동은 최대 15mm(대략 0.2%)가 발생하였지만 안전범위인 0.5% 이내를 보여주고 있다. 이러한 결과들을 토대로 최대수평변위의 안정성의 신뢰도와 지반개량재 벽면공의 타당성에 대한 가능성을 검증하였다.

• 한국운동역학회지
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• 제15권4호
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• pp.85-95
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• 2005

The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle during One Hand Backhand Stroke and Two Hand Backhand in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head direction were defined. 1. In three dimensional maximum linear velocity of racket head the X axis and Y axis(horizontal direction) showed $-11.04{\pm}2.69m/sec$, $-9.31{\pm}0.49m/sec$ before impact, the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball. It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. The stance distance between right foot and left foot was mean $75.4{\pm}5.86cm$ during one hand backhand stroke and $72.6{\pm}4.67cm$ during two hand backhand stroke. 2. The three dimensional anatomical angular displacement of trunk in interna rotation-external rotation showed most important role in backhand stroke. and is follwed by flexion-extension. the three dimensional anatomical angular displacement of trunk did not show significant difference between one hand backhand stroke and two hand backhand stroke but the three dimensional anatomical angular displacement of trunk was bigger than one hand backhand stroke. 3. while backhand stroke, the flexion-extension and adduction-abduction of right shoulder joint showed significant different between one hand backhand stroke and two hand backhand stroke. the three dimensional anatomical angular displacement of right shoulder joint showed more flex and abduct in one hand backhand stroke. 4. The three dimensional anatomical angular displacement of left shoulder showed flexion, adduction, and external rotation at impact. after impact, The angular displacement as adduction-abduction of left shoulder changed motion direction as abduction. angular displacement of left shoulder as flexion-extension showed bigger than the right shoulder.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.413-420
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• 2012

Purpose: The purpose of this setback genioplasty study is to develop a prediction method for the calculated osteotomy angle using horizontal and vertical changes as well as to evaluate the proportion of hard and soft tissue changes. Methods: Twelve patients who had received setback genioplasty with other maxillofacial surgery were examined. Three lateral cephalograms were taken just before surgery, immediately after surgery, and 3 months later surgery. A reference line was established to the reference point of the inner most point of the lingual symphysis cortex, incisor tip, and 2nd molar cusp tip. Measuring was conducted from pogonion (Pg), menton (Me), labrale inferius (Li), Mentolabial fold, soft tissue pogonion (Pg'), and soft tissue menton (Me') to the reference lines. Results: In setback genioplasty, the skeletal Pg moved posteriorly 5.07 mm. The ratios of soft tissue to hard tissue movement were 36% posteriorly and 62% inferiorly at Pg', 67% posteriorly and 104% inferiorly at Me', and 34% anteriorly and 164% posteriorly at Li. In reduction & setback genioplasty, skeletal Pg moved posteriorly 4.63 mm and skeletal Me moved superiorly 3.63 mm. The ratios of soft tissue to hard tissue movement were 76% posteriorly and 18% superiorly at Pg', 68% posteriorly and 42% superiorly at Me', and 44% anteriorly, 124% posteriorly at Li. The calculated mean slope angle, based on ${\Delta}H/{\Delta}V$ ratio, was 61.25 and the measured mean slope angle was 60.17. Thus, the calculated and measured slope angles have a similarity. Conclusion: In setback genioplasty, soft tissue moves posteriorly and inferiorly. In particular, at the Me' and Pg', the inferior movement of the soft tissue is greater than the posterior movement. Also, the predictable results (measured slope angle) after operation can be achieved by the calculated slope angle. Thus, the relationship of soft and hard tissue changes must be considered as the results are predictable.

• 한방재활의학과학회지
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• 제30권4호
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• pp.143-154
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• 2020

Objectives To analyze the prognosis of patients with low back pain according to the severity of abnormal lumbar lordotic angle and Ferguson's angle. Methods Data from electronic medical record of a total of 199 patients hospitalized in Korean medicine hospital were analyzed. With the sagittal view of lumbar spine X-ray, lumbar lordotic angle was defined as the angle between the superior endplate of L1 with the inferior endplate of L5. Ferguson's angle was defined as the angle between the superior surfaces of the sacral with a horizontal line. 'Measure Cobb's Angle Tool' of 'INFINITT PACS' was used to measure both angles. Lumbar lordotic angle and Ferguson's angle were subdivided into five sections. The number of days from onset and the duration of hospitalization were analyzed in each section. Results Severe hypolordotic lumbar lordotic angle group were found to have longer medical history and hospitalization duration than the control group. The ratio of long-term hospitalization (over 15 days) and chronic medical history (over 180 days) of patients with severe hypolordotic Ferguson's angle were significantly higher than the control group. The ratio of patients with chronic medical history (over 180 days) was significantly higher in severe hyperlordotic Ferguson's angle group than the control group. Conclusions Severe hypolordotic lumbar lordotic angle was related to patient's prognosis. Both severe hyperlordotic and severe hypolordotic Ferguson's angle were found to be related to patient's prognosis. However, a moderate loss of lumbar lordotic angle and Ferguson's angle was not related to prognosis of low back pain patients.

• 한국운동역학회지
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• 제15권3호
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• pp.161-173
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• 2005

Recently among several tennis techniques forehand stroke has been greatly changed in the aspect of spin, grip and stance. The most fundamental factor among the three factors is the stance which consists of open, square and closed stance. The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle according to open stance patterns during forehand stroke in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVlEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head angle were defined 1. In three dimensional maximum linear velocity of racket head the X axis showed $11.41{\pm}5.27m/s$ at impact, not the Y axis(horizontal direction) and the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. the stance distance between right foot and left foot was mean $74.2{\pm}11.2m$. 2. The three dimensional anatomical angular displacement of shoulder joint showed most important role in forehand stroke. and is followed by wrist joints, in addition the movement of elbow joints showed least to the stroke. The three dimensional anatomical angular displacement of racket increased flexion/abduction angle until the impact. after impact, The angular displacement of racket changed motion direction as extension/adduction. 3. The three dimensional anatomical angular displacement of trunk in flexion-extension showed extension all around the forehand stroke. The angular displacement of trunk in adduction-abduction showed abduction at the backswing top and adduction around impact. while there is no significant internal-external rotation 4. The three dimensional anatomical angular displacement of hip joint and knee joint increased extension angle after minimum of knee joint angle in the forehand stroke, The three dimensional anatomical angular displacement of ankle joint showed plantar flexion, internal rotation and eversion in forehand stroke. it could be suggest that the plantar pressure of open stance during forehand stroke would be distributed more largely to the fore foot. and lateral side.

• 한국운동역학회지
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• 제15권3호
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• pp.95-104
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• 2005

To know the proper setup posture for the various clubs, changes of setup variables according to the change of golf club length was investigated. Swing motions of three male low handicappers including a professional were taken using two high-speed videocameras. Four clubs iron 7, iron 5, iron 3 and driver (wood 1) were selected for this experiment. Three dimensional motion analysis techniques were used to get the kinematical variables. Mathcad and Kwon3D motion analysis program were used to analyze the position, distance and angle data in three dimensions. The variables divided into three categories 1) position and width of anterior-posterior direction 2) position and width of lateral direction 3) angles and evaluated based on the theories of many good golf teachers. Major findings of this study were as follows. 1.The stance (distance between ankle joints) was increased as the length of the club increased but the increasing width was not large. It ranges from 5cm to 10cm and professional player showed small changes. 2. Forward lean angle of trunk was decreased (more erected) as the length of the club increased. It ranges from 30 degrees for iron7 to 25 degrees for driver. 3. Angle between horizontal and right shoulder were increased as the length of the club increased. It ranges from 10 degrees to 20 degrees and professional player showed small changes. 4. Anterior-posterior position of the shoulders were located in front of the foot for all clubs and the difference between the shoulder and knee position was decreased as the length of the club increased. 5. Anterior-posterior position of grip (hand) was located almost beneath the shoulders (2.5cm front) for iron7, but it increased to 10cm for the driver. This grip adjustment makes the height of the posture increased only 5cm from iron7 to driver. 6. Lateral position of grip located at 5cm left for the face of iron7, but it located at the right side (behind) for the face of driver. 7. Lateral position of the ball located at the 40%(15cm) of stance from left ankle for iron7 and located at the 10% (5cm) of stance for driver. 8. Head always located at the right side of the stance and the midpoint of the eyes located at the 37% of stance from the right ankle for all clubs. This means that the axis of swing always maintained consistently for all clubs. 9. Left foot opened to the target for all subject and clubs. The maximum open angle was 25 degrees. Overall result shows that the changes of the setup variables vary only small ranges from iron7 to driver. Paradoxically it could be concluded that the failure of swing result from the excessive changes of setup not from the incorrect changes. These findings will be useful for evaluating the setup motion of golf swing and helpful to most golfers.

• 수산해양기술연구
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• 제43권1호
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• pp.49-61
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• 2007

Otter boards in the trawl are the one of essential equipments for the net mouth to be spread to the horizontal direction. Its performance should be considered in the light of the spreading force to the drag and the stability of towing in the water. Up to the present, studies of the otter boards have focused mainly on the drag and lift force, but not on the stability of otter boards movement in 3 dimensional space. In this study, the otter board is regarded as a rigid body, which has six degrees of freedom motion in three dimensional coordinate system. The forces acting on the otter boards are the underwater weight, the resistance of drag and spread forces and the tension on the warps and otter pendants. The equations of forces were derived and substituted into the governing equations of 6 degrees of freedom motion, then the second order of differential equations to the otter boards were established. For the stable numerical integration of this system, Backward Euler one of implicit methods was used. From the results of the numerical calculation, graphic simulation was carried out. The simulations were conducted for 3 types of otter boards having same area with different aspect ratio(${\lambda}=0.5,\;1.0,\;1.5$). The tested gear was mid-water trawl and the towing speed was 4k't. The length of warp was 350m and all conditions were same to each otter board. The results of this study are like this; First, the otter boards of ${\lambda}=1.0$ showed the longest spread distance, and the ${\lambda}=0.5$ showed the shorted spread distance. Second, the otter boards of ${\lambda}=1.0$ and 1.5 showed the upright at the towing speed of 4k't, but the one of ${\lambda}=0.5$ heeled outside. Third, the yawing angles of three otter boards were similar after 100 seconds with the small oscillation. Fourth, it was revealed that the net height and width are affected by the characteristics of otter boards such as the lift coefficient.

• 한국측량학회지
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• 제40권4호
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• pp.325-332
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• 2022

우주 측지 기술 사이의 상대적인 위치 관계를 설명하는 벡터를 결정하기 위해서는 VLBI IVP (Very Long Baseline Interferometry Invariant Point)의 위치를 정밀하게 계산하여야 한다. 이를 위해 일반적으로 VLBI 안테나에 반사 타겟을 부착한 후 필라들로부터 경사 거리, 수평각, 수직각을 관측한다. 그 다음 단계에서는 관측값과 미지수를 연결하는 수학 모델을 이용하여 조정 계산을 수행하게 된다. 따라서 계산된 미지수는 관측값의 정밀도에 영향을 받게 된다. 이때 특히 문제가 되는 것은 반사 타켓이 일반적인 측량 정밀도를 확보하기 어려운 곳에 위치하고 있다는 점이다. 즉, 반사 타겟의 방향을 조정하여 측량 기기에 정확하게 맞출 수 없다는 것이다. 따라서 이러한 부분은 관측 오차에 또 다른 형태로 나타날 것이며 조정 계산 시 오차 모델링에 오류를 발생시킬 수도 있다. 본 연구에서는 조정 계산 후 계산된 잔차의 특성에 대한 분석을 수행하였다. 먼저 관측 타입별 통계 분석을 통해 정규성을 검정하였으며 분산에 차이가 있는 지에 대한 검정도 실시하였다. 관측 타입별로 등분산 검정을 한 경우 분산이 서로 다른 것으로 나타났다. 각 필라에 대해 관측 타입별 등분산 검정을 했을 때 경사 거리와 수평 및 수직각 사이에는 분산에 차이가 있는 것으로 나타났다. 따라서 결합 측량으로부터 최적의 결과를 얻기 위해서는 관측 오차에 대해 보다 세분화된 모델링이 필요한 것으로 나타났다.

• Earthquakes and Structures
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• 제23권5호
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• pp.445-462
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• 2022

To investigate and evaluate the seismic damage behaviors of steel reinforced recycled concrete (SRRC) filled circular steel tube composite columns, in this study, the cyclic loading tests of 11 composite columns was carried out by using the load-displacement joint control method. The seismic damage process, hysteretic curves and performance indexes of composite columns were observed and obtained. The effects of replacement rates of recycled coarse aggregate (RCA), diameter thickness ratio, axial compression ratio, profile steel ratio and section form of profile steel on the seismic damage behaviors of composite columns were also analyzed in detail. The results show that the failure model of columns is a typical bending failure under the combined action of horizontal loads and vertical loads, and the columns have good energy dissipation capacity and ductility. In addition, the replacement rates of RCA have a certain adverse effect on the seismic bearing capacity, energy consumption and ductility of columns. The seismic damage characteristics of composite columns are revealed according to the failure modes and hysteretic curves. A modified Park-Ang seismic damage model based on the maximum displacement and cumulative energy consumption was proposed, which can consider the adverse effect of RAC on the seismic damage of columns. On this basis, the performance levels of composite columns are divided into five categories, The interlayer displacement angle and damage index are used as the damage quantitative indicators of composite columns, and the displacement angle limits of composite columns at different performance levels under 80% assurance rate are calculated as 1/105, 1/85, 1/65, 1/28, and 1/25 respectively. On this basis, the damage index limits corresponding to each performance level are calculated as 0.045, 0.1, 0.48, 0.8, and 1.0 respectively. Finally, the corresponding relations among the performance levels, damage degrees, interlayer displacement angles and damage indexes of composite columns are established. The conclusions can provide reference for the seismic design of SRRC filled circular steel tube composite columns, it fills the vacancy in the research on seismic damage of steel reinforced recycled concrete (SRRC) filled circular steel tube composite columns.

• 한국지반공학회논문집
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• 제25권10호
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• pp.17-30
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• 2009

지하에 공동을 건설하는 터널 공사의 경우 초기 응력의 집중 및 발파와 같은 시공단계에서의 과도한 에너지의 적용으로 인하여 주변 암반에 손상을 발생시킨다. 이러한 손상의 발생은 터널에 작용하는 하중 및 터널 주변 암반의 흐름조건에 상당한 영향을 끼친다. 이러한 이유로 터널 주변에 발생하는 손상구간에 대하여 다양한 연구가 수행되었다. 본 연구에서는 유사암석으로 제작된 공동이 존재하는 절리모델의 이축압축실험을 통하여 공동주변의 손상발생을 연구하였다. 절리면은 수평면과 $30^{\circ}$, $45^{\circ}$, $60^{\circ}$의 조건으로 형성되었으며, 초조강시멘트 재료를 이용하여 유사절리모델을 제작하였다. 이축압축 실험결과 공동주변에서는 절리면에 수직한 방향으로 인장균열의 발생이 관측되었으며, 균열의 진행으로 인하여 암반블록이 형성되었으며, 진행하는 인장균열이 다른 절리면에 도달하여 암반블록이 완전히 형성된 경우 탈락하는 과정을 보였다. 이러한 인장균열의 진전은 절리면의 각도에 따라 상이한데 절리면의 각도가 클수록 안정적이며 진행성의 균열 진전 양상이 관측되었다. 이러한 인장균열의 발달은 절리면으로 구성된 암편을 보로 가정 할 경우 공동의 곡률로 인한 기하학적 형상의 불규칙성으로 인하여 모멘트가 작용하는 것으로 판단된다. 이상의 실험결과를 입자요소해석 방법을 기반으로 하는 PFC 2D를 이용하여 모사하였다. 해석결과 실험에서 관측한 바와 같이 절리면 각도가 작을수록 손상대의 폭은 넓어지며 인장균열의 진행에 의한 암반블록의 형성이 관측되었다. 또한 상호작용이 발생하는 균열을 조사한 결과 수치해석에서도 절리면의 각도가 작은 조건에서 진행성의 파괴가 나타났다.