• 제목/요약/키워드: Area integral function

검색결과 34건 처리시간 0.023초

좌표계 연성에 의한 동력전달계 포함 차량 운동 시뮬레이션 연구 (The study of a Vehicle Dynamic Simulation Including Powertrain About the Coordinate System Connectivity)

  • 정일호;양홍익;윤지원;박태원;한형석
    • 한국정밀공학회지
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    • 제22권5호
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    • pp.130-137
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    • 2005
  • Recently, the importance of CAE research is growing with the advances of the automotive and computer industry. In addition, multi-body dynamics and powertrain analysis are the most important factors in improving the vehicle design. Since engine torque with curve-data was used for analyzing full car simulation in the multi-body dynamics system for many years, it is impossible to assess the concurrent analysis of the engine and powertrain element included in a real full car system. In powertrain, since vehicle are usually modeled as a simple mass and a inertia, they can not be seen as real cars. Moreover, it is hard to obtain additional dynamics data other than the longitudinal velocity value in movement. Because of the reason that was previously discussed, it is necessary to consolidate the two parts as one routine program for design and development through the coordinate system connectivity, and presented here is a program named O-DYN. Using an object-oriented language C++, this program has a good structure with the valuable characteristics of objectivity, inheritance, and reusability. The reliability of this multi-body dynamics program is examined by DADS, which is the general dynamics program, using DAE solver and PECE integral function with the common coordinator separation method. As a result, we can obtain a better solution and total dynamics data in either area through this process. This program will be useful for analyzing full car simulation with powertrain.

2차원 어류 서식처 모의를 이용한 격리된 구하도의 연결성 복원에 따른 서식지 개선 평가 (Evaluation of Habitat Improvement Using Two-Dimensional Fish Habitat Modeling after the Connectivity Restoration in an Isolated Former Channel)

  • 김석현;김다나;조강현
    • Ecology and Resilient Infrastructure
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    • 제2권2호
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    • pp.137-146
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    • 2015
  • 하천 본류와 구하도 사이의 횡적 연결성은 하천-홍수터 생태계에서 생태적 기능을 유지하는데 매우 중요하다. 본 연구는 2차원 평균수심 유한요소 모형인 River2D를 사용하여 만경강에서 직강화로 인해 격리된 구하도의 연결성을 가상으로 복원하고 평수기와 홍수기 조건에서 어류 서식처 변화를 평가하였다. 평가 대상 어종은 정수성 어종인 붕어 (Carassius auratus)와 유수성 어종인 피라미 (Zacco platypus)를 선정하였다. 물리서식처모의 결과에 의하면, 연결성 복원 전후의 붕어와 피라미의 가중가용면적 (weighted usable area, WUA)은 복원 후에 증가하였으며 양방향 복원이 일방향 복원보다 어류 서식처 복원에 효과적이었다. 또한 가중가용면적의 증가율은 평수기보다 홍수기에 더 높았다. 특히 피라미의 경우 홍수기에 구하도의 연결성이 양방향 복원되었을때 구하도 내의 가중가용면적이 복원 전 대비 약 4배로 크게 증가할 것으로 예측되었다. 본 연구 결과 만경강에서 본류와 구하도의 연결성이 복원되었을 때 정수성 어류와 유수성 어류의 서식처가 모두 증가할 것으로 예상되며, 일방향 복원보다 양방향 복원이 더 효과적인 것으로 나타났다. 또한 복원된 구하도는 홍수기 때 어류의 피난처 역할을 할 것으로 기대되었다.

Progress of Composite Fabrication Technologies with the Use of Machinery

  • Choi, Byung-Keun;Kim, Yun-Hae;Ha, Jin-Cheol;Lee, Jin-Woo;Park, Jun-Mu;Park, Soo-Jeong;Moon, Kyung-Man;Chung, Won-Jee;Kim, Man-Soo
    • International Journal of Ocean System Engineering
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    • 제2권3호
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    • pp.185-194
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    • 2012
  • A Macroscopic combination of two or more distinct materials is commonly referred to as a "Composite Material", having been designed mechanically and chemically superior in function and characteristic than its individual constituent materials. Composite materials are used not only for aerospace and military, but also heavily used in boat/ship building and general composite industries which we are seeing increasingly more. Regardless of the various applications for composite materials, the industry is still limited and requires better fabrication technology and methodology in order to expand and grow. An example of this is that the majority of fabrication facilities nearby still use an antiquated wet lay-up process where fabrication still requires manual hand labor in a 3D environment impeding productivity of composite product design advancement. As an expert in the advanced composites field, I have developed fabrication skills with the use of machinery based on my past composite experience. In autumn 2011, the Korea government confirmed to fund my project. It is the development of a composite sanding machine. I began development of this semi-robotic prototype beginning in 2009. It has possibilities of replacing or augmenting the exhaustive and difficult jobs performed by human hands, such as sanding, grinding, blasting, and polishing in most often, very awkward conditions, and is also will boost productivity, improve surface quality, cut abrasive costs, eliminate vibration injuries, and protect workers from exposure to dust and airborne contamination. Ease of control and operation of the equipment in or outside of the sanding room is a key benefit to end-users. It will prove to be much more economical than normal robotics and minimize errors that commonly occur in factories. The key components and their technologies are a 360 degree rotational shoulder and a wrist that is controlled under PLC controller and joystick manual mode. Development on both of the key modules is complete and are now operational. The Korean government fund boosted my development and I expect to complete full scale development no later than 3rd quarter 2012. Even with the advantages of composite materials, there is still the need to repair or to maintain composite products with a higher level of technology. I have learned many composite repair skills on composite airframe since many composite fabrication skills including repair, requires training for non aerospace applications. The wind energy market is now requiring much larger blades in order to generate more electrical energy for wind farms. One single blade is commonly 50 meters or longer now. When a wind blade becomes damaged from external forces, on-site repair is required on the columns even under strong wind and freezing temperature conditions. In order to correctly obtain polymerization, the repair must be performed on the damaged area within a very limited time. The use of pre-impregnated glass fabric and heating silicone pad and a hot bonder acting precise heating control are surely required.

뇌졸중(腦卒中) 환자(患者)의 신체적(身體的).심리적(心理的).사회적(社會的) 적응도(適應度)에 관(關)한 연구(硏究) (A Study on the Degree of Physical, Psychological and Social Adaptation of CVA Patients)

  • 황현숙;박경숙
    • 기본간호학회지
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    • 제3권2호
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    • pp.213-233
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    • 1996
  • This study was made on 274 apoplectics patients who received the rehabilitation therapy and tests on physical, psychological and social adaptations as outpatients in 23 general hospitals in the Seoul and Kyungi area. The basic data on degree of improvement of apoplectic patients studied from rehabilitation therapy. Data was collected over a period of 63 days, from February 21st till April, 23, 1996. The assigned physical therapist conducted direct interviews with patients after he answered the distributed questionnaires for each individual patient. The colleted data was processed by the $SPCC/C^+$ method. The results of the tests conducted to meascne the the degree of ADL dependency, depression and social activity corresponding to the physical, psychological, and social adaptation. The details are ; 1) The test to meascne the degree of ADL dependency, corresponding to the study of physical adaptation of CVA patients, indicated a mean score of 2.57(ideal score is 1.0) with a standard deviation of ${\pm}0.75$. The worst score was 3.95 while the best score was a perfect 1.0, representing a severe range of dependency. The distribution was centered with a median of 2.65 and a mode of 2.68. 2) The test to meascne the degree of depression which corresponds to the level of psychological adaptation yielded a mean of 2.99 which is higher than the normal limit of 2.45. The standard deviation was ${\pm}0.52$ and the worst score and the best score were 4.35 and Respectirdy. The distribution was centered with a median of 3.00 and a mode of 3.00. 3) The test to meascne the degree of social activities for the level of social adaptation indicated a very low mean score of 26.52 (perfect score is 144), with the standard deviation of ${\pm}16.23$. Some patients scored as high as 100, but others scored as low as 3. The distribution of social activities at a very low level was shifted to the left with a median of 24.00 and a mode of 20.00. 4) Factors influencing the level of physical, psychological and social adaptation are as follows : Factors significantly influencing the level of physical adaptation measured by ADL dependency are age, personal guardian, payer of medical expenses, and paralysis of the right arm, right leg and facial paralysis. Factors significantly influencing the level of psychological adaptation measured by the degree of depression, are age, marital status, education, medical history of individual and family, speech impediment, and facial paralysis. Factors significantly influencing the level of social adaptation measured by the degree of social activity are age, marital status, education, employment status, and the burden of medical expense. 5) The Corelationship is significant(9.00), between ADL dependeing as degree of physical adaptation and depreseion as degree of psychologial adaptation. ADL dependency is proportional to depression. But social activity is inversely protional to ADL dependeny and depression. In conclusion, the increased care for physical function of the patients is not the only necessary means to better facilitate the appropriate adaptation of CVA patients. The introduction of a solid rehabilitation program for psychological and social adaptation will also play the integral part of the treatment of CVA patients.

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