Earticle

This study investigated the muscular activity of the lower muscles during variation of Nordic exercises following changes of the Nordic angles and the base slope angles. Twenty-one healthy participants were par-ticipated in this study. Participants performed six variations of Nordic exercises including two Nordic angles positions and three base slope angles. Each Nordic exercise defined as Nordic angle 10°, 15° and base slope angle 0°, 10°, 15°. During the Nordic exercises, erector spine, glu-teus maximus, biceps femoris, gastrocnemius activities and subjective difficulties (Borg RPE score) were measured. The activities of all mus-cles and subjective difficulties were significantly greater with the 15° of Nordic exercise compared to the 10° of Nordic exercise, regardless of base slope angles. There were significant differences in gluteus maxi-mus, biceps femoris, gastrocnemius, and the Borg RPE score between three base slope conditions (P<0.05). The Borg RPE score and activities of the gluteus maximus were increased with the increases of base slop angles from 0° to 15°. Conversely, the activities of the gastrocnemius and biceps femoris were decreased with the increases of base slop angles from 0° to 15°. Present study indicates that application of the greater Nordic angle during the Nordic exercise is advantageous for activating lower extremity muscles. Using the base slopes during the Nordic exercise could be used for selective activation of the lower muscles. High base slope angles inducing greater knee flexion could maximize the exercise effects for activating gluteal muscles rather than lower leg muscles such as biceps femoris and gastrocnemius.

산지가 많이 분포하는 우리나라는 지형 특성상 도로, 철도, 건축물 등을 건설하는 과정에서 깎기비탈면이 발생하는 경우가 많다. 건설 과정에서 생성된 깎기비탈면의 상단부에는 기존 산지의 한 부분인 상부 자연사면이 위치하게 된다. 깎기비탈면의 안정성을 평가할 때, 상부 자연사면의 경사가 비탈면 안정성에 미치는 영향에 대해서는 많은 연구가 이루어지지 않았다. 본 연구에서는 깎기비탈면 상단부에 위치한 상부 자연사면이 경사 및 해석 범위에 따라 달라지는 안전율의 변화를 검토해보고 안정해석에 반영하기 위한 방안을 논의해보고자 한다. 상부 자연사면의 형상이 비탈면의 안정성에 미치는 영향을 검토하기 위하여 간단한 비탈면 모형을 가정하고 상부 자연사면의 경사 및 해석 범위를 조정하여 안정해석을 수행하였다. 해석 결과, 깎기비탈면의 안전율을 적합하게 도출하기 위해서는 상부 자연사면의 경사를 일정 부분 포함해야 하는 것으로 나타났다. 본 연구에서는 사질토 특성의 비탈면의 경우, 최소 12m 이상, 점성토 특성의 비탈면의 경우 18m 이상을 안정해석 범위에 포함하여야 한다.

Because of very mountainous topography features in Korea, cutting slope tends to be generated during the construction of road, railroad and the building structure. A natural slope is usually on the top of cutting slope created during construction. As for evaluating the stability of cutting slope, the effect of a natural slope on slope stability has not yet much been studied. This study thus is intended to review the safety of natural slope on cutting slope that may vary depending on slope and analysis scope and then seeks the way of incorporating it into stability analysis. A stability analysis was conducted on a simple model assumption while adjusting the slope and analysis scope in a bid to evaluate the effect of natural slope pattern on slope stability. Consequently, a certain part of natural slope should be included to adequately estimate the safety level of cutting slope. This study suggests that at least 12m should be included for sandy soil slope in the scope of stability analysis, while 18m for cohesive soil slope.

본 연구는 제주지역의 철골 산형라멘구조에 대해서 보의 경간길이, 건물처마높이 등을 변수로 하였을 때 효율적인 지붕경사각을 제시하고자 하였다. 본 논문에서 연구의 범위는 제주지역에 해당하는 풍하중, 강재는 , 지점은 힌지로 제한하였다. 구조해석은 벽에 가새가 없는 산형철골프레임구조가 연직하중과 횡력을 받는 경우에 대해서 MIDAS Gen/w프로그램을 이용하여 수행하였으며, 그 결과 얻은 결론은 다음과 같다. 첫째, 지붕의 경사각이 클수록 조합응력비는 크게 나타났다. 이러한 결과는 풍하중에 비해 지붕의 고정하중 및 활하중이 매우 작아서 나타나는 결과로 판단된다. 따라서 경제적인 설계를 위해서는 지붕경사각을 작게 하는 것이 효율적인 것으로 나타났다. 둘째, 보의 경간길이와 지붕경사각에 따른 부재의 조합응력비 증가율에 대한 연구결과, 보의 경간길이가 증가함에 따라서 지붕경사각의 증가에 따른 영향은 더 작아지는 것으로 판단된다. 셋째, 건물의 처마높이와 지붕경사각에 따른 부재의 조합응력비 증가율에 대한 연구결과, 건물의 처마높이가 증가함에 따라서 지붕경사각의 증가에 따른 영향은 더 작아지는 것으로 판단된다.

This paper presents a study on an efficient angle of roof slope of the steel gable frame structures in Jeju Island. In this paper, the study is limitted to the steel gable frame structures which has hinge support, steel yield strength of SS400 and wind load of Jeju Island. The Steel gable frame structures with varying span length of beam, eaves hight of structures and angle of roof slope were analyzised. An analysis of the steel gable frame structures without wall-braces was carried out by MIDAS Gen/w program. The conclusions obtained from this study on an efficient angle of roof slope of the steel gable structures in Jeju Island are as follows. First, The larger an angle of roof slop is the higher the combined strength ratio, the lower an angle of roof slop is the more economical. This result is come from which the dead and live load of roof are very light. Second, It is found that the longer the span length of beam is the lower an increasing rate of combined strength ratio according to increase angle of roof slope. Third, It is found that the higher an eaves hight of structures is the lower an increasing rate of combined strength ratio according to increase angle of roof slope.

본 연구에서는 유동학적 토석류 모델에서 이용되는 하상에서 유사의 균형농도식을 구성하는 인자들 중에서 하상경사, 입자밀도, 내부마찰각이 유사의 균형농도에 미치는 영향을 검토하였다. 입자의 밀도는 유사농도에 큰 영향을 주지 않은 반면, 하상경사는 큰 영향을 주었으며, 하상경사가 30°를 넘어서면 유사농도는 급격히 증가하다가 37°정도에서 -50이하로 크게 감소한 후 0으로 수렴하였다. 또한 내부마찰각조건에 따른 유사농도를 계산한 결과, 하상경사 5°에서는 큰 차이가 없으나, 내부마찰각이 작아질수록 하상경사의 영향을 크게 받으며 증가하고 있었다. 특히 내부마찰각이 20°에서 30°의 범위와 하상경사가 20°에서 30°로 존재하는 범위에서는 체적농도가 극한치로 발산하는 결과를 얻을 수 있었다. 따라서 토석류모델을 현장에 적용할 때는 하상경사와 내부마찰각의 일정 범위에 대한 체적농도의 값을 미리 설정해 두고 적용하는 방법을 통해서 전체적으로 보다 안정적인 계산을 하는 것이 필요하다고 판단되었다.

In this study, we investigated the effects of the debris flow model parameters such as bed slope, soil density and internal friction angle on mean volumetric concentration. While the soil density showed little effect on mean concentration under the condition from 2.5 to 3.0, the bed slope greatly influenced on mean concentration. The mean concentration was increased steeply in high bed slope over 30° and dropped to -50 in bed slope of 37° and converged to zero. In lower bed slope of 5°, friction angle showed minor effects on mean concentration. However, in high bed slope, as friction angle got smaller, the mean concentration increased steeply. Especially, at the range of 20° to 30° of friction angle and bed slope, the mean concentration jumped discontinuity. For the stable simulation in field case, it was thought that a proper mean concentration value should be applied in particular range of bed slope and friction angle.

The purpose of this study was to investigate the results of putting stroke which are face angle at impact, swing path of club, and green slope. For this study, a pendulum putting machine and a movable plate were used. Ball rolling distance was set at 1.2m. The control group(CG) does not have an angle and for example, the face angle is 0 degree, the swing path is 0 degree and the green slope is 0 degree. Nine experimental groups have one other condition. The origin of the coordinate was set at the corner of the plate and the ball was set on(70,0). In this study, x stands for direction, y stands for distance, and x+y unites a distance and a direction. Results suggested that the slope of the green was exposed to affect the big effect on the direction of move of the ball the most. The face angle has an effect on the direction of the ball in case one is big(more than 2 degrees). However, small angle did not change the direction of ball movement. The distance of the ball is almost constant(less than ±5cm) in spite of the transformation of the club. In the case of a distance and a direction, the slop of the green affected the big effect most. The face angle of 3 degrees affected big effect.

Solar radiation through a window has a big effect on the heating, cooling load and lighting load of a building. This study aims to present the proper slope and optimal orientation range of a window in the southern area by reviewing the interior daylighting time and inflow point. This study simulated the slope change of 0o, 5o, 10o, 15o, and 20o each to the outside and the orientation division of W, S-45o-W, S, S-45o-E, E for this. As a result, the proper slope of a window was reviewed to be 10o and the optimal orientation of a window was reviewed to be S.

purpose: Changes in the femoral posterior condylar offset (PCO), tibial posterior slope angle (PSA), and joint line height (JLH) after cruciate-retaining total knee arthroplasty (CR-TKA) were evaluated to determine their influence on the flexion angle. materials and methods: A total of 125 CR-TKAs performed on 110 patients were retrospectively reviewed. Pre- and postoperative PCO, PSA, and JLH were compared using correlation analysis. Independent factors affecting the postoperative flexion angle of the knee were analyzed.results: The PCO was 28.2±2.0 mm (range, 24.5 to 33.1 mm) preoperatively and 26.7±1.8 mm (range, 22.2 to 31.2 mm) postoperatively (r=0.807, p<0.001). The PSA was 10.4°±4.9° (range, 1.6° to 21.2°) preoperatively and decreased to 4.9°±2.0° (2.2° to 10.7°) postoperatively (r=?0.023, p=0.800). The JLH was 16.2±3.0 mm (range, 10.2 to 27.5 mm) preoperatively and 16.1±2.6 mm (range, 11.1 to 24.8 mm) postoperatively (r=0.505, p<0.001). None of the independent factors affected the flexion angle (p>0.291). conclusions: Although the PCO and JLH did not change significantly after CR-TKA, the PSA decreased by 5.5° with a small range of variation. Restoration of the PCO and JLH could promote optimization of knee flexion in spite of the decreased PSA after CR-TKA.

Purpose: The purpose of this study was to evaluate the correlation between the posterior tibial slope and the maximal angle of flexion after total knee arthroplasty. Materials and Methods: Seventy nine cases (63 patients, 60 females and 3 males), which received total knee arthroplasty with the Nexgen LPS system from Jan 2001 to Jan 2004, were enrolled. We divided all cases into two subsets in two ways. Firstly, group A (up to 10°, 44 cases) and group B (over 10°, 35 cases) were divided according to the mean value of the postoperative posterior tibial slope. Secondly, group α (up to -4°, 39 cases) and group β (over -4°, 40 cases) were divided according to the mean difference between the preoperative posterior tibial slope and the postoperative posterior tibial slope. We compared the maximal angle of flexion between group A and group B, group α and group β, respectively. Results: There was no significant difference between group A and group B, and also between group α and group β in terms of maximal angle of flexion. Conclusions: There was no significant correlation between the postoperative posterior tibial solpe and the maximal angle of flexion.

Purpose: To evaluate the effect of femoral condylar offset and posterior tibial slope on maximal flexion angle of the knee in posterior cruciate ligament (PCL)-sacrificing total knee arthroplasty (TKA, Medial-Pivot Knee System). Materials and Methods: Forty-five knees in 35 patients who could be followed up more than 1 year after PCL-sacrificing TKA were evaluated retrospectively. We measured and analyzed the preoperative and postoperative maximal flexion angle, posterior femoral condylar offset difference, posterior femoral condylar offset ratio difference, and tibial slope. Results: The mean maximal flexion angle after TKA was 118.44o±9.8o and significantly related to postoperative tibial slope (11.78o±6.2o) in correlation analysis (R=0.451, p=0.002). There was no statistical relationship between the postoperative maximal flexion angle and the posterior femoral condylar offset difference (3.24±3.862 mm, R=0.105, p=0.493) and posterior femoral condylar offset ratio difference (0.039±0.029 mm, R=-0.163, p=0.284). Conclusions: The maximal flexion angle of the knee after PCL-sacrificing TKA was significantly related to the postoperative tibial slope. Therefore, posterior tibial slope can be considered as a factor that affects maximal flexion angle after PCL-sacrificing TKA.

The purpose of the current study was to optimize shrimp-pot design to allow greater control over the size of captured individuals for the purposes of shrimp resource management. Tank experiments were conducted to determine the optimal slope length and slope angle by analyzing the sizes of shrimp that entered 25 model pots with combinations of five different slope lengths and five different angles. Shrimp size was measured using carapace length. The results showed that as the slope angle of the pot increased, the size of individuals that entered the pot increased. Furthermore, as the slope length increased, each of the five different slope angles of the pot increased, and the size of individuals entering also increased. The data indicated that the optimum pot design for reducing the capture of immature individuals had a $75^{\circ}$ slope angle and a 35.4 cm slope length.

기존의 연구에서 삼각형 돌출부의 크기 즉 돌출부 길이 및 돌출부 경사각 변화에 따른 전단거동 및 파괴 형상 특성에 대한 광범위한 실험적 연구는 부족하였다. 본 연구에서는 직접전단시험기를 사용하여 삼각형 돌출부의 전단거동에 있어서 돌출부의 길이 및 경사각 특성이 표면 돌출부의 파괴 형상 특성에 미치는 영향을 규명하고자 한다. 이를 위하여 돌출부 길이는 4가지로 변환하였고, 수직응력은 3가지로, 그리고 돌출부 경사각은 3개의 각도로 변환하면서 총 36회의 시험을 수행하였다. 시험을 수행한 시편은 3차원 형상측정기를 사용하여 파괴 형상 특성을 정량적으로 분석하였다. 이러한 시험을 통하여, 수직응력 변화에 따른 돌출부의 파괴 형상 특성을 조사하였다. 또한 각각의 경사각에서 돌출부의 길이를 변화시켜 시험을 수행함으로써, 특정 수직응력 하에서 돌출부가 파괴되는 길이 및 높이를 정의하였다.

Most of previous studies have insufficiently investigated the shear behavior and fracturing characteristics, experimentally in respect to the change of size of tooth-shaped surface asperity such as length and slope angle in a broad range. This study investigates the influence of the length and slope angle of a tooth-shaped surface asperity on the fracturing characteristics and the interface shear strength by using direct shear test apparatus. A total of 36 interface direct shear tests were conducted by changing the three types of slope angle of surface asperity, four type of length, and three types of normal stress. The shape of fractured surface after the test was quantified by using a three-dimensional surface roughness measurement apparatus. Through the experimental test results, the characteristics of fractured shape of surface asperity according to the normal stress were investigated. In addition, fractured length and height were quantified at each slope angle of surface asperity under a certain normal stress condition.

산사면에서 우곡간 침식과정을 연구하기 위하여 복합방울인공강우기 중 단일크기강우기를 이용하여 인공강우 실험을 실시하였다. 실험지역은 여주화강암으로 동일 기반암이나, 토양입도특성이 다른 두 지역을 선정하였다. 인공강우는 사면경사 10도와 20도에서 각각 실시되었으며, 강우 중에 실시간으로 토양수분변화를 모니터링 하였으며 연구결과는 다음과 같다. 첫 번째, 점토질 성분이 높은 곳과 경사가 큰 곳에서 보다 많은 유출과 토양침식이 발생하였다. 이는 sealing 및 crusting 효과가 점토질 성분이 많을수록, 경사가 급한 곳일수록 커짐을 의미한다. 두 번째, 토양수분변화와 투수율 변화와의 관계는 역의 관계가 추정된다. 세번째, 지표유출은 누적강우에너지 73~235(J/m2/10min)의 범위에서 형성된 것으로 나타났으나, 지표유출 형성과 관련하여서는 자연강우에서의 실험이 요구된다.

Rainfall simulating performed to know the processes of interrill erosion on mountainous slope using by single-sized drop simulator. The two areas simulated by rainfall were laid on same bedrock as Yeoju Granite, but their soil characters are different. Rainfall simulating performed on 10 and 20 slope degree, respectively, and also soil water monitored contemporary with rainfall simulating. We suggest like below from simulating results; First, the runoff and soil loss increased as mud content and slope degree increasing, i.e. the effects of sealing and crusting made more runoff and soil loss on high mud content and steep slope angle, repectively. Second, the relationship with the change of soil water and infiltration rate were shown negative function but needs additional research to know more about this relationship. The last, runoff generated between 73 and 235(J/m2/10min) of comulative rainfall energy, but the experiments under natural rainfall and other rainfall simulator are needed to discuss rainfall energy how to contribute on runoff generation.

Objective: The purpose of this study was to analyze kinematic variables according to ground slope angle during golf putting. Method: 26 collegiate golfers (age: 22.54±2.15 kg, height: 174.64±6.07 cm, weight: 71.35±9.27 kg, handicap: 5.11±4.50) were participated, and 8 motion capture cameras (250 Hz), Nexus, and Kwon3DXP software were used to collect data. It was performed repeated measures ANOVA and Bonferroni adjustment. Alpha set at .05. Results: Body alignments were not significantly different at address. Putter head trajectory and loft angle were significantly different, and AP direction of acceleration of putter head was significantly different. However, ML and SI direction of acceleration of putter head were not significantly different. Conclusion: Therefore, it was identified that ground slope angle was affected the kinematic variables during putting, and it will be performed that correlation analysis between putting success rate and kinematic variables according to ground slope angle during golf putting.

본 연구는 국내에서 산자태 발생빈도가 매우 높은 편마암 풍화토를 대상으로 산사태 모형실험장치를 이용하여 강우강도 및 사면경사에 따른 간극수압 변화의 관계를 파악하기 위하여 수행되었다. 본 연구에서는 강우강도와 사면경사의 변화에 따른 다양한 실험조건하에서 일정 시간 간격으로 간극수압, 사면붕괴양상 및 변위 등을 각각 측정하였다. 실험결과에 따르면, 강우강도에 따른 간극수압의 관계는 강우강도가 클수록 간극수압 증가시간이 빠르며, 모형 토조의 위치별 간극수압 증가시간도 사면 상부에서 가장 빠른 것으로 측정되었다. 이를 표준사를 이용한 실험결과(채병곤 외, 2006)와 비교해 볼 때, 편마암 풍화토는 강우의 침투속도가 표준사에 비해 느린 것을 알 수 있으며, 이로 인해 사면하부로의 강우이동이 상대적으로 원활하지 않아 사면 상단부에서 간극수압의 증가가 빠른 것으로 해석된다. 한편, 간극수압의 증가는 사면의 경사가 작은 경우 먼저 발생하는 것으로 나타났다. 이러한 현상 역시 편마암 풍화토의 느린 강우 침투속도에 기인하는 것으로 생각된다.

This study was conducted to characterize on the relationships among rainfall intensity, slope angle and pore water pressure in the gneissic weathered soil by landslide laboratory flume tests. Under the several test conditions dependent on rainfall intensity and slope angle, the authors measured pore water pressure, failure and displacement of slope on a regular time interval. According to the test results, the increasing times of pore water pressures have direct proportional trends to the rainfall intensity. The pore water pressure was increased earlier at the head part of slope than the toe part. Compared with the test results of Chae et al(2006), the results of this study explain that the seepage velocity in the gneissic weathered soil is slower than that in the standard sands. It results in faster and ear-lier increase of pore water pressure at the head part of slope due to slow flow of water in the gneissic weathered soil. In case of the relationship between slope angle and pore water pressure, gentle slope angle has faster increase of pore water pressure than steeper slope angle. It is also thought to be due to slow seepage velocity and flow velocity in the gneissic weathered soil.

본 연구의 목적은 콘크리트 U형 벤치 플륨관 수로에 설치되는 수로 탈출 경사로의 경사각에 따른 개구리 행동 특성을 분석하여 탈출 경사로 기준 각도를 제언하는 것이다. 실험 장치는 현장에서 적용되는 콘크리트 수로 탈출장치와 형태 및 재질을 유사하게 제작하였다. 경사로 실험을 위해 논 습지에 서식하는 한국산개구리를 선정하였다. 경사로에서 보여지는 개구리의 주요 행동은 '뛰기', '걷기', '미끄러짐'이었으며, 경사각에 따른 행동 결과를 기록한 후 통계 분석하였다. 경사각은 20°-60° 범위에서 10° 간격으로 5개의 경사각을 설정하여 비교·분석하였다. 연관성 검증은 카이제곱 검증 방법을 사용하였다. 분석결과 30°와 40°는 통계적으로 유의한 차이가 없었다. 이는 '생태통로 설치 및 관리지침'의 30° 이하의 설치 기준에 있어, 현장에서 이를 40°까지 일부 허용해 줄 수 있는 근거로 활용될 수 있는 결과이다. 하지만 수로 탈출 경사로가 한국산개구리뿐 아니라 다양한 소형 야생동물을 대상으로 하고 있다는 점에서 추가 연구가 필요할 것이다.

The purpose of this study is to propose the angle-limit of the escape ramp by analyzing the frog behavior characteristics according to the inclination angle of the waterway escape ramp installed in the concrete U-bench plume pipe channel. Forthe experiment, an escape test device was manufactured with the same shape and number of materials applied in the field. And Rana coreana living in paddy wetlands were sel selected. The main behaviors of frogs on the slope were 'jumping', 'crawling' and 'slipping', and afterrecording the behavioralresults according to the inclination angle, statistical analysis was conducted using the chi-square test method. As a result of the analysis, there was no statistically significant difference between 30° and 40°. This result is an evidence for expanding the standard of inclination angle 30° suggested in the 'Guidelines for Installation and Management of Ecological Pathways' to a maximum of 40°. However, further research is required in that the escape ramp targets not only Korean frogs but also various small wild animals. However, considering that various wild animals are affected by artificial canals, additional studies using various target wild animals are needed.

This study is an experimental research for the dispersion behavior and impact characteristics of debris flow according to change of slope. Large scale experimental setup for the debris flow was established to simulate the artificial rainfall and control the ground slope. Parameters such as materials of debris flow, slope, and length of slope were used for the experiments. After the experiments, it was found that the speed of ground material components was increased about 28~47%. It was found that speed can be increased by increasing the particle size. Furthermore, maximum/final loads for ground material components were increased 89% for the coarse aggregate and 68% for the fine aggregate comparing with sand.

Occupational disease among typists such as Carpal Tunnel Syndrome(CTS) and tendonitis has increased along with rapid expansion of office automation. During typing, the posture can be defined as forearm pronation, ulnar abduction, wrist extension and finger flexion. The CTS results from awkward posture between forearm-wrist-hand and the keyboard arrangement. Therefore, ergonomic principles should be emphasized in keyboard design. The objective of the study is to improve keyboard design by analyzing anatomical posture of forearm and hand during typing. An experimental study was performed to investigate relationships between a keyboard and typing performance. Results showed that typing performance is dependent to angles and slopes of a keyboard. Statistical analysis indicated that the suggested ergonomic keyboard improved typing speed significantly(17%).