• Earthquakes and Structures
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• 제15권5호
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• pp.453-462
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• 2018

Damages to buildings affected by a near-fault strong ground motion are largely attributed to the vertical component of the earthquake resulting in column failures, which could lead to disproportionate building catastrophic collapse in a progressive fashion. Recently, considerable interests are awakening to study effects of earthquake vertical components on structural responses. In this study, detailed modeling and time-history analyses of a 12-story code-conforming reinforced concrete moment frame building carrying the gravity loads, and exposed to once only the horizontal component of, and second time simultaneously the horizontal and vertical components of an ensemble of far-field and near-field earthquakes are conducted. Structural responses inclusive of tension, compression and its fluctuations in columns, the ratio of shear demand to capacity in columns and peak mid-span moment demand in beams are compared with and without the presence of the vertical component of earthquake records. The influences of the existence of earthquake vertical component in both exterior and interior spans are separately studied. Thereafter, the correlation between the increase of demands induced by the vertical component of the earthquake and the ratio of a set of earthquake record characteristic parameters is investigated. It is shown that uplift initiation and the magnitude of tensile forces developed in corner columns are relatively more critical. Presence of vertical component of earthquake leads to a drop in minimum compressive force and initiation of tension in columns. The magnitude of this reduction in the most critical case is recorded on average 84% under near-fault ground motions. Besides, the presence of earthquake vertical components increases the shear capacity required in columns, which is at most 31%. In the best case, a direct correlation of 95% between the increase of the maximum compressive force and the ratio of vertical to horizontal 'effective peak acceleration (EPA)' is observed.

• 한국운동역학회지
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• 제17권2호
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• pp.207-216
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• 2007

The purpose of this study was to biomechanical analysis Judo's Kuzushi throwing motion in order to increase the effectiveness of Nage-waja(throwing technique). The Tori was a Judo player with 18 years experience(4th degree) while the Uke was a player with 2 years experience(1st degree). The kinematic data was captured using the Vicon motion system (7 cameras) and the kinetics were recorded by force plates(2 AMTI). The following were the results; While leaning to the front the subject's trunk's angle was $14.5^{\circ}$, the lower limbs angle was $23.8^{\circ}$, knee angle was $179.6^{\circ}$ and the vertical reaction of the left leg was 325.42N(BW 0.34) and the right leg was 233.7N(BW 0.47). While leaning back the subject's trunk's angle was $11.3^{\circ}$, the lower limbs angle was $4.1^{\circ}$, knee angle was $1761^{\circ}$ and the vertical reaction of the left leg was 299.53N(BW 0.43) and the right leg was 441.7N(BW 0.64). While leaning to the left the subject's trunk's angle was $30.8^{\circ}$, the lower limbs angle was $2.7^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 711N(BW 1.03) and the right leg was 9.2N(BW 0.01). While leaning to the right the subject's trunk's angle was $36.5^{\circ}$, the lower limbs angle was $10.4^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 13.2N(BW 0.02) and the right leg was 694.7N(BW 1.01). While leaning to the left front corner the subject's trunk's angle was $19.8^{\circ}$ (front) and $15.1^{\circ}$ (left), the lower limbs angle was $17.8^{\circ}$ (front) and $2.4^{\circ}$ (left), knee angle was $177.8^{\circ}$ (front) and $173.9^{\circ}$(left), and the vertical reaction of the left leg was 547.4N(BW 0.8) and the right leg was 117.8N(BW 0.17). While leaning to the right front corner the subject's trunk's angle was $15.4^{\circ}$ (front) and $17.7^{\circ}$ (right), the lower limbs angle was $21.1^{\circ}$, (front) and $5.7^{\circ}$ (right), knee angle was $175.5^{\circ}$ (front) and $178.9^{\circ}$(right), and the vertical reaction of the left leg was 53N(BW 0.08) and the right leg was 622.4N(BW 09). While leaning to the left rear corner the subject's trunk's angle was $9.2^{\circ}$ (back) and $13.8^{\circ}$ (left), the lower limbs angle was $2^{\circ}$, (back) and $5.7^{\circ}$ (left), knee angle was $175.5^{\circ}$ (back) and $172.8^{\circ}$(left), and the vertical reaction of the left leg was 698.2N(BW 1.02) and the right leg was 49.6N(BW 0.07). While leaning to the right rear corner the subject's trunk's angle was $8.9^{\circ}$ (back) and $19.6^{\circ}$ (right), the lower limbs angle was ${0.6^{\circ}}_"$ (back) and $3.1^{\circ}$ (right), knee angle was $174.6^{\circ}$ (back) and $175.6^{\circ}$(right), and the vertical reaction of the left leg was 7.2N(BW 0.01) and the right leg was 749.4N(BW 1.09). It was observed that during the Judo motion Kuzushii the range of the COM varied from $26.5{\sim}39.9cm$. It was concluded that the upper body leaned further than the lower body as there was knee extension. There was high left leg reaction forces while leaning to the left and likewise for the right side. It was therefore deduced that the Kuzushi was a more effective throwing technique for the left side.

• 한국항해항만학회지
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• 제34권3호
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• pp.195-203
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• 2010

본 논문은 통합채광시스템의 동력학 해석을 다루고 있다. 통합채광시스템은 채광선, 수직양광관, 중간 저장 장소인 버퍼, 유연관, 자항식집광기로 구성되어 있다. 자항식집광기와 버퍼는 6자유도의 강체로 가정하였으며, 수직양광관과 유연관의 동적거동 해석을 위해 집중질량 매개방법을 이용한 이산화 모델을 적용하였다. 채광선에 대한 운동은 포함시키지 않았지만 경계조건을 통하여 채광선의 움직임을 표현하였다. 연약한 해저면을 주행하는 차량에는 연약지반 역학 모델을 적용시켰다. 수직양광관-버퍼, 버퍼-유연관, 유연관-자항식집광기의 연결에는 회전구속과 볼 구속조건을 사용하였다. 연성 동력학 모델의 운동방정식을 유도하기 위해 국부좌표계를 사용하였으며, 4개의 오일러 매개변수를 사용하여 각 시스템의 자세를 표현하였다. 통합 채광시스템의 운동 방정식 해를 구하기 위해서 증분-반복법을 적용하였으며, 시간영역 적분기는 newmark-${\beta}$를 사용하였다. 통합 채광시스템의 동적 거동 해석을 수치해석을 통해 분석하였다.

• 한국해양공학회지
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• 제31권3호
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• pp.202-207
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• 2017

This paper presents the results of an experimental study on the motions and mooring characteristics of a floating vertical axis wind turbine system. Based on a comparison of regular wave experiment results, the motions of structures with different types of mooring are almost the same. Based on the tension response results of a regular wave experiment with a catenary mooring system, the mooring lines in front of the structure have a larger tension effect than the back of the structure by the drifted offset of the structure. The dynamic response spectrum of the structure in the irregular wave experiments showed no significant differences in response to differences in the mooring system. As a result of the comparison of the tension response spectra, the mooring lines have a larger value with a drifted offset for the structure, as shown in the previous regular wave experiment. The results of the dynamic response of the structure under irregular wave and wind conditions showed that the heave motion response is influenced by the coupled effect with the mooring lines of the surge and pitch motion due to the drifted offset and steady heeling. In addition, the mooring lines in front of the structure have a very large tension force compared to the mooring lines in back of the structure as a result of the drifted offset of the structure.

• 한국해양공학회지
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• 제25권4호
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• pp.7-11
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• 2011

The installation phase for a topside module suggested can be divided into 9 stages, which include start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the topside module from a transport barge to a crane vessel takes place in the first three stages, from start to lifting, while the transfer of the module onto a floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with significant wave height (1.52m), with suggested force equilibrium diagrams. The effects of the hydrodynamic interactions between the crane vessel and barge during the lifting stage have been considered. The internal forces caused by the load transfer and ballasting are derived for the lifting phases. The results of these internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the lifting phases, the internal force induced pitch motion is too small to show its influence. However, the effect of the internal force on the wave-induced heave responses in the lifting phases is noticeable in the irregular sea condition because the transfer mass-induced draught changes in the floating structure are observed to have higher amplitudes than the external force induced responses.

• Journal of Biosystems Engineering
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• 제43권3호
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• pp.194-201
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• 2018

Purpose: The objective of this study was to propose a formula for the theoretical grain mean transport velocities of an elliptically moving oscillator by modifying the grain mean transport velocity formula applied to linear motion and to compare the calculated values with the experimental values of grain mean transport velocity. Methods: The values of the throwing index ($K_v$) and the maximum horizontal velocities for various positions on the elliptical oscillator were obtained using kinematic analysis. To obtain the actual grain transport velocity, the mean transport velocities of perilla grains at six positions on the sieve surface were measured using a high-speed camera and compared with the theoretical values. The cam with an eccentric bearing on the oscillator was designed to be eccentric by 1.6 cm so that the lengths of the major axis of the elliptical motion were 3.2-3.6 cm. The material used in the experiments was perilla grain. Results: The experimental result was consistent with the theoretical value calculated using the proposed formula ($R^2$ is 0.80). It is considered that the angle difference between the maximum accelerations in the directions vertical and horizontal to the sieve has as much influence on the grain mean transport velocity as the value of Kv itself. Conclusions: It was possible to theoretically obtain the grain mean transport velocities through a screening device in elliptical motion by modifying the formula of the grain mean transport velocities used in linear motion.

• Structural Engineering and Mechanics
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• 제23권3호
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• pp.293-308
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• 2006

This paper presents a complete and consistent formulation to study the seismic response of a free-standing ship supported by an arrangement of n keel blocks which are all located in a dry dock. It is considered that the foundation of the system is subjected to both horizontal and vertical in plane excitation. The motion of the system is classified in eight different modes which are Rest (relative), Sliding of keel blocks, Rocking of keel blocks, Sliding of the ship, Sliding of both keel blocks and the ship, Sliding and rocking of keel blocks, Rocking of keel blocks with sliding of the ship, and finally Sliding and rocking of keel blocks accompanied with sliding of the ship. For each mode of motion the governing equations are derived, and transition conditions between different modes are also defined. This formulation is based on a number of fundamental assumptions which are 2D idealization for motion of the system, considering keel blocks as the rigid ones and the ship as a massive rigid block too, allowing the similar motion for all keel blocks, and supposing frictional nature for transmitted forces between contacted parts. Also, the rocking of the ship is not likely to take place, and the complete ship separation from keel blocks or separation of keel blocks from the base is considered as one of the failure mode in the system. The formulation presented in this paper can be used in its entirety or in part, and they are suitable for investigation of generalized response using suitable analytical, or conducting a time-history sensitivity analysis.

• Ocean Systems Engineering
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• 제10권1호
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• pp.87-110
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• 2020

Catamaran has recently been a choice to support a typical vertical axis turbine in floating tidal current energy conversion system. However, motion responses associated with the catamaran can reduce the turbines efficiency. The possibility to overcome this problem isto change the catamaran parameter by varying and simulating the demi-hull separations to have lower motion responses. This simulation was undertaken by Computational Fluid Dynamic (CFD) using potential flow analysis. Cases of demi-hull separation were considered, with ratios of demi-hull separation (S) to the breadth of demi-hull (B), ^S/_B of 3.45, 4.95, 6.45, 7.2 and 7.95. In order to compare to the previous works in the literature, the regular wave was set with wave height of 0.8 m. Furthermore, the analysis was carried out by irregular waves with significant wave height, H_s, of about 0.09 to 1.5 m and the wave period, T, of about 1.5 to 6 s or corresponding to the wave frequency, ω, of about 1.1 to 4.2 rad/s. The wave spectrum was derived from the equation of the International Towing Tank Conference (ITTC). For the case of turbines-loaded catamaran under consideration, the new finding is that the least significant amplitude response can be satisfied at the ratio ^S/_B of 7.2. This study indicates that selecting a right choice of demi-hull separation ratio could contribute in reducing motion responses of the tidal current turbines-loaded catamaran.

• 복식문화연구
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• 제6권2호
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• pp.66-76
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• 1998

In order to investigate the effect of shoulder pad affecting the arm movement, eleven women volunteers of standard body whose age is from eighteen to twenty-four(x±1σ) were chosen and this experiment had done according to front-vertical motion, side-vertical motion and horizontal motion of upper limps for tow different materials of shoulder pad(sponge, non-woven) and four different thickness of shoulder pad(0.6cm, 0.8cm, 1.2cm). On the base of this, this study, when putting on shoulder pad, try to find the reform method of shoulder part pattern. The results are as follows. 1. When puting on shoulder pad to blouse pattern to rise shoulder pad for rate of two-third per thickness is seemingly the best for sensory evaluation. So, when putting on shoulder pad, we understand that in order to improve sensory evaluation. So, when putting on shoulder pad, we understand that in order to improve sensory evaluation of clothes, when that, rising shoulder pad for ate of two-third per thickness is the best. 2. From the results of measure of functional volume and physiological value for functionality evaluation according to thickness and material, motion of shoulder pad, 1.2 cm thickness and non-woven material is evaluated the worst for functionality. 3. From the results of sensory evaluation and functionality evaluation of material of shoulder pad, sponge material is superior for functionality but not for sensory evaluation, non-woven material is superior for sensory evaluation non-woven material is superior for sensory evaluation but not for functionality. So, think that it had better use sponge material for functional clothes, non-woven material for aesthetical clothes. 4. From the results of functionality of clothes, when putting on shoulder pad, the worst discomfortable parts are the armpit part and the shawl part, functionality of these part shoulder be reformed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.447-454
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• 1999

The compressive capacity and the soil plugging resistance of single open-ended pipe pile were completely decreased in the previous study on the behavior of shorter single pile during simulated seaquake induced by the vertical component of earthquake. But the capacity of single open-ended pipe pile with greater penetration and the capacity of piles group with shorter penetration were expected to be stable after seaquake motion. In this study, first, 2-piles or 4-piles are driven into the calibration chamber included in saturated fine medium sand with several simulated penetrations, and the compressive load test for each piles group was performed. Then, about 95 % compressive load of the ultimate capacity was applied on the pile head during the simulated seaquake motion. Finally, In confirm the reduction of pile capacity during the simulated seaquake motion, the compressive load test for each single pile or piles group after seaquake motion was performed. During the simulated seaquake, the compressive capacity of open-ended pipe piles with greater penetration ( 〉about 27 m) was not degraded even in deep sea deeper than 220 m and soil plug within open-ended pipe pile installed in deep sea was stable after seaquake motion. Also, in the case of 2-piles or 4-pile groups, the compressive capacity after seaquake motion was not degraded at all regardless of pile penetration depth beneath seabed, sea water depth and seaquake frequency.