• 수산해양기술연구
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• 제53권3호
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• pp.256-265
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• 2017

Seafood is attracting attention as a future food industry. In recent years, the demand for fishery equipment of mechanization, automation, and unmanned was increased due to the environment affected by seafood processing, stricter regulations on safety, decline and aging of fishery worker. Ark shell (Scapharca subcrenata) was being produced in many steps in the production process. The process has been made such as collection-landing-washing-first sort (goods/non-goods)-transports-second sort (size). It was undergone first and second steps by delivering to the consumer. Here, the first step is to sort goods to collection and the second step is to sort by size. The fishery workers need ten people in first step and six people in second step. The workload of one hour per kg is 4,247 kg/h in first step and 2,213 kg/h in second step. In addition, the goods ratio by work process was 79% in first step and 98% in the second step. In this process, a lot of fishery worker and working time is needed. Therefore, this study developed elemental techniques for an automated size sorting system considering the working process problem, time and situation for washing and sorting of ark shell.

• Ocean Systems Engineering
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• 제5권3호
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• pp.181-198
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• 2015

An OSV (Offshore Support Vessel) is being used to install a structure which is laid on its deck or an adjacent transport barge by lifting off the structure with its own crane, lifting in the air, crossing splash zone, deeply submerging, and lastly landing it. There are some major considerations during these operations. Especially, when lifting off the structure, if operating conditions such as ocean environmental loads and lifting off velocity are not suitable, the collision can be occurred due to the relative motion between the structure and the OSV or the transport barge. To solve this problem, this study performs the physics-based simulation of the lifting off step while the OSV installs the structure. The simulation includes the calculation of dynamic responses of the OSV and the structure, including the collision detection between the transport barge and the structure. To check the applicability of the physics-based simulation, it is applied to a problem of the lifting off step by varying the ocean environmental loads and the lifting off velocity. As a result, it is confirmed that the operability of the lifting off step are affected by the conditions.

• 한국운동역학회지
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• 제21권5호
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• pp.621-629
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• 2011

The purpose of this study was to analyze the kinematics of the women's triple jump event at the 2011 Daegu World a Chmpionships by comparing them to those of the 2009 Berlin World Championships. The kinematic data were gathered from two steps before take off to the landing using a 7-camera panorama system. The data were then divided into 3 phases for each of the 8 participants. Similar average results were found the final contestants in the Daegu and Berlin championships, 14.58 m and 14.51 m, respectively. The first step had a relatively short length percentage (29%) compared to the hop and jump (36% and 35%, respectively). At the take off, the horizontal velocity was the lowest for the step, followed by the hop and jump. These results were different from the results for the men, who had an order of hop, step, and jump. Overall, in a comparison of the Daegu and Berlin participants, the vertical speed at take off for the three events was reduced compared to the horizontal speed.

• 디지털융복합연구
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• 제12권9호
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• pp.465-474
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• 2014

본 연구는 배드민턴 전위와 후위에서 스트로크 이후 제2동작의 움직임에 대한 피드백을 제공함으로서 훈련의 효율성을 제고시키고자 하였다. 본 연구를 통해 다음과 같은 결론을 얻었다. 스매시의 경우 타점을 높일 수 있도록 Impact 타임을 조절해야한다. S1의 스매시는 스텝 스매시로 가장 빠른 라켓헤드의 속도를 보여 임팩트 시 강하고 효율적인 힘의 전달을 하고 있는 것으로 나타났으며, 스트로크 구사 시 Impact 시 라켓속도와 Max속도가 유사해 Impact 타임이 가장 좋은 것으로 나타났다. 1step 시 S5를 제외한 모든 선수들 착지 시 전방에 있는 오른발로 1step을 하는 것으로 홉 스텝을 이용한 첫 스텝이 이루어진 것으로 나타났다. 스트로크 시 최적의 스윙을 만들기 위해서는 팔꿈치 관절이나 손목관절의 협응 동작에 필요한 최적의 조건을 만들어 주는 것이 중요하다. 라켓의 회전반경은 크고 셔틀콕의 선속도도 빠르게 해야 한다. 스텝은 양 발의 조직적인 움직임으로 좌우 밸런스가 중요하다. 실제 경기에 있어서 step은 대부분이 2-4보 정도의 스텝으로 이루어져야하며, 상황에 따라 적절한 step 구사와 민첩성, 순발력 강화 훈련 프로그램 등이 요구된다.

• 한국항공운항학회지
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• 제19권2호
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• pp.52-57
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• 2011

The procedures of Continuous Descent Approach(CDA) is designed to minimize the thrust required during landing, thereby reducing fuel consumption, noise and emissions compared to conventional approach procedures. Widespread implementation of CDA would result in significant reductions in the environmental impact and aircraft operation costs. This paper estimated the possible economic effects from the perspective of airliners through cost-benefit analysis, provided that the CDA is introduced. It is now proposed that a more comprehensive analysis model, which includes the reduced ATC communication burden between controllers and pilots, not to mention the economic aspect, should be established for the improvement.

• Journal of Korean Neurosurgical Society
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• 제51권3호
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• pp.182-186
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• 2012

In conventional percutaneous disc surgery, introducing instruments into disc space starts by inserting a guide needle into the triangular working zone. However, landing the guide needle tip on the annular window is a challenging step in endoscopic discectomy. Surgeons tend to repeat the needling procedure to reach an optimal position on the annular target. Obturator guiding technique is a modification of standard endoscopic lumbar discectomy, in which, obturator is used to access triangular working zone instead of a guide needle. Obturator guiding technique provides more vivid feedback and easy manipulation. This technique decreases the steps of inserting instruments and takes safer route from the peritoneum.

• 한국운동역학회지
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• 제21권5호
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• pp.529-540
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• 2011

The purpose of this study was to evaluate the kinematic characteristics of $5^{th}$ and $6^{th}$ hurdle clearances during the final of the 110-m hurdles at the IAAF World Championships, Daegu 2011. To this end, the hurdling motions of the top 4 ranked male hurdlers in the competition were analyzed. A total of 12 cameras were used to record their motions, with a sampling frequency of 120 Hz. The cameras were calibrated using $11{\times}2{\times}1\;m$ control objects that covered all of the lanes (1st~8th lanes). After analyzing all the data, we arrived at the following results. In the take-off phase, all athletes revealed similar take-off times (CT), and similar distances from the take-off to hurdleto (L1) and hurdle to landing (L2). In particular, Turner, ranked $3^{rd}$, had an inconsistent L2 and may need further training to correct it. In the flight phase, Richardson, ranked $1^{st}$, showed the longest flight distance, whereas Xiang, who was ranked $2^{nd}$, showed the highest CG height from the hurdle. For the step patterns, to increase the pitch frequency, Richardson and Xiang used shorter 3-step lengths than Turner and Oliver.

• 한국운동역학회지
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• 제25권1호
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• pp.39-47
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• 2015

Objective : The purpose of this study was to investigate the velocity conversion coefficient and invariance for the optimal phase ratio on the performance of the women's triple jump. Methods : Three-dimensional kinematic data were obtained from the three finalists of the women's triple jumper competition at the 2011 Daegu IAAF World Championships. Computer simulations were performed using the biomechanical model of the triple jump to optimize the phase ratio for the longest actual distance for all athletes with altered velocity conversion coefficients. Results : Top elite triple jumpers showed better technical consistency at the phase ratio. Also, no consistent relationship was observed between the loss in horizontal velocity and the gain in vertical velocity across supporting the three phase. In addition, regardless of the magnitude A1, all athletes were optimized with jump-dominated technique. Finally, as the magnitude of A1 increased, the athletes showed better performance. The obtained overall distance jumped showed the longest actual distance when the optimal phase ratio was transferred from hop-dominated to jump-dominated(the step ratio was 30%~31%), and when the optimal phase ratio was transferred from balanced to jump-dominated(the step ratio was 27%~29%). Conclusion : Future studies need to be conducted in order to explore the active landing motion and the inclination angle of the body with the velocity conversion coefficient simultaneously at each supporting phase.

• 안보군사학연구
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• 통권3호
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• pp.121-167
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• 2005

The great strategy of China has been changing depending on the time, change of surrounding environment and personality of leaders of the time. However, the process of the change was not the drastic change but has maintained the consistency through the course of modification and development. The great strategy of Mao Ze-dong was to have the objective in 'World Great Nation' with the facilitation of the 'Surpass Strategy' and 'Autonomy, Independence and Alliance strategy' to successfully build up the political great nation, but he entrapped China's politics and economy into the point of no return by excessive war preparation under 'The Principle of Inevitable World War', striving of rapid communism and other policies. The Deng Xiao-ping era also targeted for ‘World Great Nation’ but, unlike Mao Ze-dong, he had the foundation in the 'The Principle of Evitable World War' and undertook the ‘Peace and Development Strategy’ and ‘Peaceful Coexistence' to build up the advantageous surrounding environment for China to focus on the economic construction as the core of the nation by establishing ‘The Reform and Opening Strategy’ and 'Three-step Development Strategy‘ to have the successful soft landing of the Chinese economy with the astonishing economic development. The system of leader's group of China after Deng Xiao-ping succeeded the practical and realistic spirit of Deng Xia-ping, and based on the drastically grown economic strength, the great strategy of China is on the ‘The Great Reinvigoration of Chinese Nation’. This is one step further from the strategy of 'World Great Nation' of the past that it embraces all the minority races in China, Chinese economic sphere, foreign citizens of Chinese origin as well as Chinese residing abroad. China contemplates the time of making 'The Great Reinvigoration of Chinese Nation’ in 2050, 100 anniversary of the birth of new China.

• 제어로봇시스템학회논문지
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• 제17권7호
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• pp.659-667
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• 2011

The study of bipedal robot is towards similar shape and function with human. In this paper, we propose a human-like walking pattern compatible to the flexible foot with toe and heel structure. The new walking pattern for a bipedal robot consists of ZMP, center of mass (CoM), and ankle trajectory and is drawn by considering human kinesiology. First, the ZMP trajectory moves forward without stopping at a point even in the single support phase. The corresponding CoM trajectory to the ZMP one is derived by solving differential equations. As well, a CoM trajectory for the vertical axis is added by following the idea of human motion. The ankle trajectory closely mimics the rotational motion of human ankles during taking off and landing on the ground. The advantages of the proposed walking pattern are demonstrated by showing improved stability, decreased ankle torque, and the longer step length capability. Specifically, it is interesting to know that the vertical CoM motion is able to compensate for the initial transient response.