• 방사선산업학회지
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• 제2권1호
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• pp.43-51
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• 2008

방사선처리기술은 현재 멸균, 폴리머가교, 식품조사, 생고무가황 등 산업적으로 많은 곳에서 이용되고 있다. 현재 감마선과 전자선을 이용한 것은 방사선처리기술의 대표적인 기술이다. 이 논문의 목적은 최근의 방사선 기술을 이해하기 위해 외국의 방사선기술 동향을 살펴보고 산업현장 작업자가 방사선 관련 기술이 친숙해지기를 목적으로 그들에게 유용한 정보를 제공하기 위함이다. 본 조사를 통해 방사선이용기술이 지속적으로 성장함을 알 수 있었고, 또한 이 기술을 이용하면 제품의 다양성을 줄 수 있다는 사실도 알아냈다.

• 한국산업융합학회 논문집
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• 제18권2호
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• pp.99-109
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• 2015

This study proposes a new approach to analyze the impedance and the elasticity of a serial chain of spring-damper system, areal-time collision-free trajectory generation algorithm is proposed. The reference points on a trajectory connected by the spring-damper system have a mechanism for self-position adjustment to solve a collision problem by the impedance, and the local adjustment of each reference point is propagated through the elasticity to a real robot at the end of the spring-damper system. As a result, the overall trajectory consisting of the reference points becomes free of collision with environmental obstacles and efficient having the shortest distance as possible. In this process,, the reference points connected by the spring-damper system take role of virtual robot as global guidance for a real robot, and a cooperative is carried out by the system of robots. A control technology is proposed to implement for mobile robot.

• 한국산업융합학회 논문집
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• 제23권2_2호
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• pp.233-244
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• 2020

A double-parked car is the one that is parked in a crowded parking lot with its transmission gear in neutral position and its auxiliary brake released. A double-parked car can be moved by pushing it but doing so is very difficult and dangerous. In a previous study, we proposed an omni-directional mobile robot for moving a double parked car. In that study we adopted Mecanum wheels. Even though the proposed robot showed successful results, it has some drawbacks such as dependency on a load condition, complexity in control, inefficiency in power use, etc. To overcome those drawbacks, we propose a differential drive robot with ordinary two tire wheels. The proposed robot consists of two parts, one is a wheel part and the other is a body part. By selectively connecting or disconnecting those two parts with the aid of an electric brake, the proposed robot is able to have omni-directional mobility.

• 한국산업융합학회 논문집
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• 제18권3호
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• pp.139-149
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• 2015

In this paper, we describe a new approach to perform real-time implementation of an robust controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for robot manipulator consisting of dual arm with eight degrees of freedom at the joint space and cartesian space.

• Elastomers and Composites
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• 제43권2호
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• pp.63-71
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• 2008

종래의 고무는 대부분 수송 수단인 타이어의 재료로 사용되어 왔으며, 타이어 산업이 곧 고무 산업이라는 인식이 깊다. 본 고에서는 고무를 포함하는 고분자 엘라스토머의 새로운 응용 분야를 조명하고자 한다. 외부의 자극에 반응하는 엘라스토머의 탄성력을 이용하는 액추에이터(actuator), 종이접기의 기술을 이용하여 프로그램된 엘라스토머 이차원 구조를 삼차원으로 변환 시키는 오리가미(origami), 그리고 리소그라피 기술을 이용하여 제조된 엘라스토머 마이크로 렌즈 등의 최신 연구 분야에서의 고분자 엘라스토머의 활용을 알아보고자 한다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.234-239
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• 2002

Acoustic sounds generated by a uniform flow around a two-dimensional circular cylinder at Re=200 are simulated using finite difference lattice Boltzmann method. A third-order-accurate up-wind scheme is used for spartial derivatives, and a second-order-accurate Runge-Kutta scheme is used for time marching. The results show that in capturing very small acoustic pressure fluctuation with same frequency of Karman vortex street compared with the pressure fluctuation around a circular cylinder. The propagation velocity of acoustic sound is presented that acoustic which approaches tire upstream due to Doppler effect in the uniform flow slowly propagates, while that for the downstream quickly propagates. It is also apparent that the size of sound pressure is proportional for central distance $r^{-1/2}$ of the cylinder.

• The Journal of Asian Finance, Economics and Business
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• 제6권2호
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• pp.55-62
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• 2019

China has become the second largest economy since 2010. China's economy is supported by the rapid growth of its automobile industry. The rapid growth of the automobile and tire industry will increase the natural rubber (NR) demand as its primary raw materials. Although as a significant producer, China cannot fulfill the consumption by its domestic production. Thus China relies heavily on import from Southeast Asia countries as the primary producers of natural rubber in the world. China and Southeast Asia are dependent on their economy in terms of the availability of natural rubber as raw materials. But the economic slowdown in China since 2008 is expected to affect the international trading between China and Southeast Asia countries. This research aims to analyze the determinants of NR export from Southeast Asia to China using panel data analysis. The results show NR price, exchange rate, and China's economic slowdown significantly affect NR export to China, while Southeast Asian NR production has no significant effect. China as the main importer of NR from Southeast Asia has a big role in growing NR export in Southeast Asia. If China's economy doesn't improve soon, it will affect the economy in Southeast Asia.

• 한국수소및신에너지학회논문집
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• 제22권3호
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• pp.409-414
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• 2011

건물용 고분자연료전지는 저탄소 녹색산업화에 기여할 수 있는 대표적인 신재생에너지원으로, 정부 주도의 보급사업을 통해 초기 시장창출이 이루어지고 있다. 고분자연료전지 산업화 촉진을 위해서는 분리판을 비롯한 구성 부품의 상용화 기술개발과 저가화가 필수적이다. 탄소복합체 몰딩분리판의 적용은 고분자연료전지 상용화를 앞당기는데 기여할 것이다. 한국타이어에서 개발한 복합체 몰딩분리판은 고분자연료전지 스택 부품으로서의 요구 특성과 성능을 모두 만족시키는 것으로 나타났다. 한국타이어는 분리판 상용화 기술개발과 지속적인 생산능력 확보를 통해 국산 연료전지의 가격 및 성능 경쟁력 향상을 위해 최선의 노력을 다하고 있다.

• 한국기계가공학회지
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• 제9권1호
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• pp.25-34
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• 2010

Fretting damage reduces fatigue life of the material due to low amplitude cyclic sliding and changes in the contact surfaces of strongly connected machine and structures such as bolt, key, fixed rivet and connected shaft, which have relative slip of repeatedly very low frequency amplitude. In this study, the fretting fatigue behavior of 7050-T7451 aluminum alloys used mainly in aircraft and automobile industry were evaluated. The plain fatigue test and fretting fatigue test under cyclic bending load carried out commercial bending fatigue tester and specially devised equipments to cause fretting damage. From these experimental work, the following results obtained: (1) The plain fatigue limit for stress ratio R=-l was about 151MPa. (2) In case of fretting fatigue, fatigue limit for stress ratio R=-l about 72MPa, the fatigue limit for R=0 about 81MPa, and the fatigue limit for R=0.3 about 93MPa. (3) The fatigue limit reduction rates by the fretting damage were about 52%(R=-1), 46%(R=0) and 38%(R=0.3) respectively. (4) The fatigue limit reduction rate decreased with stress ratio increase. In fretting bending test, as stress ratio increased, occurrence of initial oblique crack by fretting decreased or phased out, so that fracture surfaces were formed by plain fatigue crack occurrence, and such tendency was notable as stress amplitude increased. (5) Tire tracks and rubbed scars were observed in the fracture surface and contacted surface.

• 한국수소및신에너지학회논문집
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• 제29권6호
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• pp.570-577
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• 2018

Composite pressure vessels made through filament winding are widely used in various fields. Numerous studies regarding composite pressure vessels have been conducted in the automotive industry to improve the space efficiency of trunks as well as the fuel efficiency. Compared with steel liquefied petroleum gas (LPG) vessels used in the conventional LPG vehicles, the use of type 4 composite pressure vessels has advantages in terms of reduction of the weight of vehicles. This study focused on development of type 4 composite pressure vessels that can be installed in the spare tire well. Those type 4 composite pressure vessels are designed with torispherical dome shapes instead of geodecis dome shapes because of the space limitation. To reduce deformation due to the stresses in the axial direction of the vessels, thereby securing the safety of the container, the reinforcing bar concept was applied. A structural analysis software, ABAQUS, confirmed the effect of the reinforcing bar on the axial deformation through the type 4 composite pressure vessel. As a result, the final winding angle of the composite layer was analyzed by applying $26^{\circ}/28^{\circ}/26^{\circ}/28^{\circ}/26^{\circ}/88^{\circ}$ The tensile stress was 939.2 MPa and the compressive stress was 249.3 MPa.