• 제목/요약/키워드: Main Axis

검색결과 537건 처리시간 0.028초

한국 남자 창던지기 선수들의 순위별 창의 운동학적 특성 (The Kinematic Characteristics of Javelin in Korean Male Javelin Throwers Following Rank)

  • 김태삼;류지선;박재명
    • 한국운동역학회지
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    • 제23권2호
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    • pp.99-108
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    • 2013
  • The purpose of this study was to analyze the kinematic characteristics of javelin to compare the characteristics between world elite athletes and local male athletes. The subjects selected 9 athletes out of total 13 athletes recorded more than 65 m in the preliminary and main competition participated in the 93rd National Sports Festival held in 2012. Three-Dimensional motion analysis using a system of 4 video cameras(Sony HXR-MC2000) at a sampling frequency of 60 fields/s was performed for this study. The Kwon3D 3.1 was used to obtain the three dimensional coordinates about the top, grip, end of javelin. And the kinematic factors of javelin calculated using Matlab2009a program. The resultant speed of javelin that affects directly to the record of performance showed 26.08 m/s indicated lower speed of about 2-3 m/s than world elite athletes. The release point appeared to have been made at the high of $1.79{\pm}0.07$ m of 99.8% of the height of the athletes. In terms of release angle, it was indicated average $33.0{\pm}3.81^{\circ}$ lower release angle compared to the world elite athletes. The attitude angle(up & down tilt angle, X axis) related to javelin indicated average $38.5{\pm}4.96^{\circ}$, its related attack angle average $5.5{\pm}5.11^{\circ}$, and yaw angle(sideslip, side attack angle) average $15.7{\pm}8.48^{\circ}$.

Investigating the effects of ultra-rapid, rapid vs. final precise orbit and clock products on high-rate GNSS-PPP for capturing dynamic displacements

  • Yigit, Cemal O.;El-Mowafy, Ahmed;Bezcioglu, Mert;Dindar, Ahmet A.
    • Structural Engineering and Mechanics
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    • 제73권4호
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    • pp.427-436
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    • 2020
  • The use of final IGS precise orbit and clock products for high-rate GNSS-PPP proved its effectiveness in capturing dynamic displacement of engineering structures caused by earthquakes. However, the main drawback of using the final products is that they are available after approximately two weeks of data collection, which is not suitable for timely measures after an event. In this study, the use of ultra-rapid products (observed part), which are available after a few hours of data collection, and rapid products, which are available in less than 24 hrs, are investigated and their results are compared to the more precise final products. The tests are designed such that harmonic oscillations with different frequencies and amplitudes and ground motion of a simulated real earthquake are generated using a single axis shake table and the PPP was used to capture these movements by monitoring time-change of the table positions. To evaluate the accuracy of PPP using ultra-rapid, rapid and final products, their results were compared with relative GNSS positioning and LVDT (Linear Variable Differential Transformer) data, treated as reference. The results show that the high-rate GNSS-PPP solutions based on the three products can capture frequencies of harmonic oscillations and dynamic displacement with good accuracy. There were slight differences between ultra-rapid, rapid and final products, where some of the tested events indicated that the latter two produced are more accurate and provide better results compared to the ultra-rapid product for monitoring short-term dynamic displacements.

EPB tunneling in cohesionless soils: A study on Tabriz Metro settlements

  • Rezaei, Amir H.;Shirzehhagh, Mojtaba;Golpasand, Mohammad R. Baghban
    • Geomechanics and Engineering
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    • 제19권2호
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    • pp.153-165
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    • 2019
  • A case study of monitoring and analysis of surface settlement induced by tunneling of Tabriz metro line 2 (TML2) is presented in this paper. The TML2 single tunnel has been excavated using earth pressure balanced TBM with a cutting-wheel diameter of 9.49 m since 2015. Presented measurements of surface settlements, were collected during the construction of western part of the project (between west depot and S02 station) where the tunnel was being excavated in sand and silt, below the water table and at an average axis depth of about 16 m. Settlement readings were back-analyzed using Gaussian formula, both in longitudinal and transversal directions, in order to estimate volume loss and settlement trough width factor. In addition to settlements, face support and tail grouting pressures were monitored, providing a comprehensive description of the EPB performance. Using the gap model, volume loss prediction was carried out. Also, COB empirical method for determination of the face pressure was employed in order to compare with field monitored data. Likewise, FE simulation was used in various sections employing the code Simulia ABAQUS, to investigate the efficiency of numerical modelling for the estimating of the tunneling induced-surface settlements under such a geotechnical condition. In this regard, the main aspects of a mechanized excavation were simulated. For the studied sections, numerical simulation is not capable of reproducing the high values of in-situ-measured surface settlements, applying Mohr-Coulomb constitutive law for soil. Based on results, for the mentioned case study, the range of estimated volume loss mostly varies from 0.2% to 0.7%, having an average value of 0.45%.

무릎관절 전치환술 환자에게 적용한 무릎 안정화 운동이 균형과 보행능력에 미치는 영향 (Effect of Knee Stabilization Exercise on Balance and Walking Ability in Patients with Total Knee Replacement)

  • 박근홍;김태원;송형봉
    • 대한정형도수물리치료학회지
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    • 제27권2호
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    • pp.69-76
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    • 2021
  • Background: Degenerative arthritis accounts for a large portion of the elderly, causing a lot of inconvenience in daily life. Total knee replacement (TKR) are performed to relieve pain in the knee joint. The purpose of this study was to determine whether knee joint stabilization exercises are effective in improving balance and walking ability in degenerative arthritis patients who have undergone TKR. Methods: A total of 30 TKR patients participated in this study. They were assigned to two groups. The experimental group, the group that underwent knee stabilization exercises, joint mobilization and general physical therapy. On the other hand, and the controlled group, the group that underwent joint mobilization and general physical therapy. All exercises were conducted thrice a week, for four weeks. The main balance outcomes were evaluated using the posture balance training system, while walking ability was assessed using a wireless 3-axis accelerometer. Results: The experimental group had significantly higher scores in postural stability testing (PST), limits stability testing, and waling ability. The post-intervention evaluation, there were significant differences in all variables between the two groups. However, no significant difference was noted in the foam eyes closed test in PST. Conclusion: This study suggests that knee joint stabilization exercises effectively improve the balance and walking ability of TKR patients. Thus, it could be presented as useful in clinical practice.

고무튜브 몰드 프리캐스트 콘크리트 유공 슬래브 개발에 관한 실험적 연구 (Experimental Study on the Development of Void Precast Concrete Slab using Rubber Tube Mold for Inner Core)

  • 배규웅;홍성엽
    • 한국건축시공학회지
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    • 제21권4호
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    • pp.293-303
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    • 2021
  • 국내 PC공장은 PC 유공 슬래브를 생산하기 위해 자동화 설비를 도입하거나 매입물 삽입을 통해 중공 단면을 구현하지만 PC공장의 과다한 초기투자비용이 생산원가의 증가라는 주요 원인으로 작용하기에 다른 대안이 필요한 상황이다. 따라서 본 연구에서는 PC 유공 슬래브 부재 생산시 고무 튜브를 내부 속빈 공간을 형성하는 거푸집으로 사용함으로써 다양한 중공 형상의 성형 및 대단면화, 초경량화, 신속생산 대응 가능을 통한 생산성 확보에 기여하고자 한다.

Management of Pulmonary Hypertension Due to Brachycephalic Obstructive Airway Syndrome in a Dog

  • Song, Yunji;Kim, Yeji;Kim, Jihyun;Kim, Kwon-Neung;Oh, Songju;Kim, Ha-Jung
    • 한국임상수의학회지
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    • 제39권5호
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    • pp.240-245
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    • 2022
  • A 15-year-old, neutered male, Shih-Tzu, was presented at the Chonnam National Veterinary Medical Teaching Hospital for evaluation of acute onset of persistent coughing, exercise intolerance, and abnormal heart sound. On thoracic auscultation, a split-second heart sound and a wheezing sound were detected on both sides of the chest walls. On physical examination, the dog's body condition score (BCS) was 7/9, and had stenotic nares. Thoracic radiographs revealed right-sided enlargement of the cardiac silhouette (vertebral heart score (VHS) 11.2; reference interval = 8.9-10.1), mild main pulmonary artery (MPA) bulging, mild interstitial infiltration, and hepatomegaly. The electrocardiogram showed right axis deviation, suggesting right ventricular hypertrophy. The echocardiographic study showed moderate pulmonary hypertension and moderate tricuspid regurgitation. There were no findings of a tracheobronchial disease, pulmonary thromboembolism, congenital shunt, left heart disease, or parasitic disease. Based on clinical signs and diagnostic findings, the dog was diagnosed with pulmonary hypertension secondary to brachycephalic syndrome. To rectify respiratory exacerbating factors, the dog was recommended weight control by restricting dietary intake and managing concurrent Cushing's syndrome. Treatments included sildenafil, pimobendan, furosemide, and ramipril. After five months of taking medications and weight control, the severity of pulmonary hypertension improved from moderate to mild. The clinical signs of the patient, including coughing and exercise intolerance, improved a lot. For 5 months of follow-up, the patient has not reported further recurrence of respiratory distress.

Conformer 모델을 이용한 물체 표면 재료의 특성에 따른 가속도 신호 기반 햅틱 질감 인식 (Acceleration signal-based haptic texture recognition according to characteristics of object surface material using conformer model)

  • 김형국;정동기;김진영
    • 한국음향학회지
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    • 제42권3호
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    • pp.214-220
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    • 2023
  • 본 논문에서는 합성곱 신경망과 트랜스포머의 장점을 결합한 Conformer 모델을 이용하여 물체 표면의 질감특성을 나타내는 햅틱 가속도 신호로부터 질감 인식 성능을 향상시키는 방식을 제안한다. 제안한 방식에서는 사람이 스타일러스와 같은 도구를 이용하여 물체 표면과 접촉하는 동안 충격음과 진동에 의해 발생한 3축 가속도 신호를 1차원 가속도 데이터로 결합하고, 오디오 신호와 유사성을 갖는 햅틱 가속도 신호로부터 로그 멜-스펙트로그램을 추출한다. 그리고 추출된 로그 멜-스펙트로그램에 Conformer 모델을 적용하여 다양한 물체의 질감을 인식하는 데 있어 주요한 지역적 및 전역적인 주파수 특징을 학습한다. 제안된 모델의 성능 평가를 위해 60개의 재질로 구성된 Lehrstuhl für Medientechnik(LMT) 햅틱 질감 데이터세트를 실험한 결과 제안된 방식이 기존 방식들보다 물체 표면 재료의 질감을 효과적으로 잘 인식할 수 있음을 보였다.

The effect of typhoon translation speed and landfall angle on the maximum surge height along the coastline

  • Qian, Xiaojuan;Son, Sangyoung
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2021년도 학술발표회
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    • pp.153-153
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    • 2021
  • Storm Storm event is one of major issues in South Korea due to devastating damage at its landfall. A series of statistical study on the historical typhoon records consistently insist that the typhoon translation speed (TS) is on slowdown trend annually, and thus provides an urgent topic in assessing the extreme storm surge under future climate change. Even though TS has been regarded as a principal contributor in storm surge dynamics, only a few studies have considered its impact on the storm surge. The landfall angle (LA), another key physical factor of storm surge also needs to be further investigated along with TS. This study aims to elucidate the interaction mechanism among TS, LA, coastal geometry, and storm surge synthetically by performing a series of simulations on the idealized geometries using Delft3D FM. In the simulation, various typhoons are set up according to different combinations of TS and LA, while their trajectories are assumed to be straight with the constant wind speed and the central pressure. Then, typhoons are subjected to make landfall over a set of idealized geometries that have different depth profiles and layouts (i.e., open coasts or bays). The simulation results show that: (i) For the open coasts, the maximum surge height (MSH) increases with increasing TS. (ii) For the constant bed level, a typhoon normal to the coastline resulted in peak MSH due to the lowest effect of the coastal wave. (iii) For the continental shelf with different widths, the slow-moving typhoon will generate the peak MSH around a small LA as the shelf width becomes narrow. (iv) For the bay, MSH enlarges with the ratio of L/E (the length of main-bay axis /gate size) dropping, while the greatest MSH is at L/E=1. These findings suggest that a fast-moving typhoon perpendicular to the coastline over a broad continental shelf will likely generate the extreme storm surge hazard in the future, as well as the slow-moving typhoon will make an acute landfall over a narrow continental shelf.

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심곡서원의 풍수 환경연구 (A Study on the Feng Shui Environment of Simgok Seowon)

  • 최덕수;박정해
    • 산업진흥연구
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    • 제8권3호
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    • pp.163-174
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    • 2023
  • 심곡서원은 조선 중기의 학자이며 정치가였던 조광조의 뜻을 기리기 위해 세운 서원이다. 풍수적 길지에 자리하고 있는데, 주산은 무곡금성체로, 원와혈을 맺고 있으며 안산은 탐랑목성체이다. 제향 공간을 혈처에 배치한 제향중심 서원이며, 사당을 중심으로 좌청룡과 우백호, 주작과 현무가 혈처를 잘 보호하고 있다. 사우를 중심으로 배치된 전형적인 중심 축선형 공간 배치이다. 강당을 전면에 배치하고 제향 공간인 사당을 후면에 배치하는 전학후묘의 형태이다. 사당을 중심으로 좌측에 천원지방의 원리를 응용한 연지를 조성하여 유식 공간과 미기후의 조절 기능, 화재시 소화의 기능을 담당한다. 건축물의 좌향과 방위, 위치 등을 결정하는 데 있어 풍수가 중요한 역할을 한다. 따라서 지형이나 바람 그리고 물의 흐름과 방위 등으로부터 자연환경과 인간의 상관관계를 정확히 파악하여 자연과 사람이 하나 되는 풍수적 공간구성은 천인합일의 미학정신의 구현이라 할 수 있다.

육상 창던지기 기록에 미치는 운동학적 요인의 탐색: 다차원적 다중회귀를 활용한 성과 예측 변수 분석 (Investigation of Biomechanical Factors in Track and Field Javelin Performance: A Multidimensional Analysis of Predictive Variables through Multiple Regression Analysis)

  • Ho-Jong Gil;Jin Joo Yang;Jong Chul Park;Young Sun Lee;Jae Myoung Park
    • 한국운동역학회지
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    • 제33권4호
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    • pp.175-184
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    • 2023
  • Objective: The purpose of this study is to investigate the effects of human motion and javelin kinematics during the energy transfer in javelin throwing on records, and to provide evidence-based training insights for athletes and coaches to enhance records. Method: Three javelin throw athletes (age: 22.67 ± 0.58 years, height: 178.33 ± 7.37 cm, weight: 83.67 ± 1.15 kg) were recruited for this study. Each athlete attempted ten maximum record trials, and the kinematic data from each performance were analyzed to determine their influence on the records. The Theia3d Markerless system was used for motion analysis. Results: Key factors were modeled and identified at each moment. In E1, main variables were COM Y (𝛽 8.162, p<.05) and COM velocity Z (𝛽 -72.489, p<.05); in E2, COM X (𝛽 -17.604, p<.05); in E3, COM X (𝛽 -18.606, p<.05), COM velocity Y (𝛽 38.694, p<.05), and COM velocity X (𝛽 66.323, p<.05). For the javelin throw dynamics in E3, key determinants were Attitude angle and Javelin velocity in the Y-axis. Conclusion: The study reveals that controlled vertical movement, center of mass management during braking, and enhanced pelvic rotation significantly improve javelin throw performance. These kinematic strategies are critical for record enhancement in javelin throwing.