• 한국철도학회논문집
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• 제3권1호
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• pp.19-26
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• 2000

The rail temperature is important to preserve the joint gap for standard length of rail and to determine the installation temperature which has direct influence on the rail buckling and failure in welded part for continuous welded rail(CWR), Therefore, we have measured and investigated various characteristics of rail temperature for each kind of rail. As the results of this, the correlation between the atmosphere temperature and the rail temperature which is commonly used by Korean Railway should be reconsidered. Also, the daily highest '||'&'||' lowest rail temperature was occurred when each temperature is higher and when it's lower. For the light rail, the rail temperature by the sun-light increases quickly and decreases late. But the time where the highest temperature is attained is same. There are some differences between the shade and sunny place about 3.0∼4.0$\^{C}$. The temperature of rail web is almost close to the conversion rail temperature for rail expansion. The wind of 1 m/s has an influence on the rail temperature around 5$\^{C}$.

• 전기전자학회논문지
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• 제9권1호
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• pp.47-56
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• 2005

본 연구에서는 불확실성과 부하 변동 하에 브러쉬없는 직접구동 전동기의 정확한 사전결정 추적성능을 제공하기 위한 새로운 개선된 강인한 가변구조 추적 제어기를 설계하였다. 리칭 페이즈를 제거하기 위한 특수 적분 슬라이딩 변은 서보 전동기의 초기 위치부터 이상 슬라이딩 모드와 가상 이상 슬라이딩 궤적을 정의한다 . 영이 아닌 슬라이딩 면에 의하여 발생되는 추적오차를 유도하였다. 외란 관측기를 갖는 연속 입력을 제안하여 불확실성과 부하 변동 하에 사전 결정 가상 이상 슬라이딩 궤적을 사전 값 내에 추적하도록 한다. 제안된 알고리듬의 유용성을 부하 변동 하에 브러쉬없는 직접구동 전동기에 대한 비교 시뮬레이션으로 입증한다.

• 한국전자거래학회지
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• 제19권1호
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• pp.15-42
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• 2014

클라우드 스토리지 서비스는 미래 모바일 및 인터넷 서비스의 핵심적인 인프라 서비스가 될 가능성이 높다. 클라우드 스토리지 서비스와 관련된 많은 기업들은 지속적인 투자를 하고 있으며, 가입자 확보를 위해 노력하고 있다. 이러한 서비스를 제공하는 기업들이 신규 가입자를 확보하고 기존 가입자를 유지하기 위해 사용자들의 서비스 사용의도가 무엇인지 확인할 필요가 있다. 따라서 본 연구에서는 클라우드 스토리지 서비스의 지속적 사용의도에 대한 실증적 연구 수행을 위해 외생 변수를 추가한 확장된 TAM 모형을 기반으로 사용자 수용의도와의 관계를 규명하고자 한다. 연구 결과, 개인의 혁신성, 자기효능감, 기능적 속성, 심리적 전환 비용과 같은 요인이 클라우드 스토리지 서비스의 지속적 사용의도에 영향을 주는 것으로 검증되었으며, 향후 클라우드 스토리지 서비스를 제공하는 기업들의 전략 수립을 위한 방향성을 제공해 줄 수 있을 것으로 기대한다.

• 한국구조물진단유지관리공학회 논문집
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• 제20권2호
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• pp.40-48
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• 2016

본 연구는 지진이 발생할 경우 장대레일교량에 있어 레일과 상판 간의 종방향 상호작용에 미치는 영향을 검토하기 위한 것으로, 해석모델에 여러 하중조합과 함께 지진하중을 적용함으로써 대상 철도교량 레일에서의 축방향 부가응력과 레일-상판 간 상대변위의 변화를 산출하였다. 해석 결과, 본 연구 대상 철도교량의 경우 철도시설공단에서 제시하고 있는 표준응답스펙트럼을 적용할 때 레일부가응력은 대부분의 하중조합에 대해 허용기준 내의 값을 보이고 있는 반면, 레일-상판 상대변위는 공단에서 제시하는 허용기준을 초과하고 있는 것으로 나타났다. 따라서 레일-상판 상대변위가 레일부가응력에 비해 상대적으로 더 허용기준을 만족시키기 어렵다는 것을 알 수 있었으며, 아울러 고베 대지진과 같은 큰 규모의 지진이 발생하면 레일부가응력과 레일-상판 상대변위는 허용기준을 충족시키지 못하므로 이에 대한 적절한 내진 대비가 필요하다.

• 한국구조물진단유지관리공학회 논문집
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• 제27권6호
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• pp.39-46
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• 2023

이 연구에서는 차세대 고속철의 증가하는 주행속도에 따라 600 km/h 까지 10 km/h 간격으로 고속철 PSC 박스 연속교량의 교량받 침에 대한 동적거동을 수치해석하였다. 경부 고속철 구간의 40미터 단경간과 2경간 연속 PSC 박스교를 연구대상으로 프레임모형을 구성하였 으며, 38자유도의 관성질량 차량모형 및 교량과 궤도의 불규칙성을 포함한 상호작용력을 고려하였다. 주행속도별 교량받침의 종방향 변위와 누적이동거리와 변위속도를 산정하여 교량의 동적거동 추이분석과 비교하였다. 또한 마찰판의 내구성능평가를 위한 장기마찰시험 기준을 적 용하였다.

• International Journal of Korean Welding Society
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• 제4권1호
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• pp.30-37
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• 2004

There have been continuous efforts on automating welding processes. This automation process could be said to fall into two categories, weld seam tracking and weld quality evaluation. Recently, the attempts to achieve these two functions simultaneously are on the increase. For the study presented in this paper, a vision sensor is made, a vision system is constructed and using this, the 3 dimensional geometry of the bead is measured on-line. For the application as in welding, which is the characteristic of nonlinear process, a fuzzy controller is designed. And with this, an adaptive control system is proposed which acquires the bead height and the coordinates of the point on the bead along the horizontal fillet joint, performs seam tracking with those data, and also at the same time, controls the bead geometry to a uniform shape. A communication system, which enables the communication with the industrial robot, is designed to control the bead geometry and to track the weld seam. Experiments are made with varied offset angles from the pre-taught weld path, and they showed the adaptive system works favorable results.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1629-1635
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• 2011

Because LRT project is large infrastructure projects investing enormous budget and required continuous maintenance after construction, it is the global trend to perform business in terms of life-cycle from the initial construction, operation to disposal. It is very important LRT to manage interfaces efficiently and to integrate vehicle, civil, track, electricity, communications, signals, operations, facilities organically. Global companies of the railway developed countries including Europe are getting orders a large rail project and preempting the world market based on engineering technology. But, domestic LRT systems engineering is the subcontracting level to the lack of practical skills and experience. Thus, technology securement is very urgent for the independence of systems engineering technology and overseas advance based turnkey. In this paper, we are going to study applicable systems engineering technology focusing on LRT system based on international standard ISO/IEC 15288.

• 기술사
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• 제34권1호
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• pp.27-34
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• 2001

On 16Dec. 1999, It was 100 years since the opening the first railroad section of 33.2km on Sep. 1899, Korea High Speed Railroad had a successful trial run of 200km/h on test track section. And the test speed 300km/h was achieved an 28 June 2000 during continuous commissioning. In the 21st century, the High Speed Railroad will be opened commercially in Korea and will contribute to technical development. Now, it is necessary to re-evaluate the role of railroad in modern society and to activate the railroad system. Ultimately, the competitive power of nation will be strengthened with energy saving, reduction of pollution and transportation cost. It conclusion the railroad system have to be expaned about 50% of total transportation to make preparations for reopening of Eurasia silk route through KyungEu railroad connection.

• Tribology and Lubricants
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• 제5권2호
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• pp.94-100
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• 1989

Friction and Wear behavior of continuous graphite fiber composites was studied for different fiber orientations against the sliding direction. The effect of fiber orientation on friction and wear of the composite and on the deformation of the counterface was investigated experimentally. Pin on disk type testing machine was built and employed to generate the friction and wear data. A graphite fiber composite plate was produced by the bleeder ply molding in an autoclave and machined into rectangular pin specimens with specific fiber orientations, i.e., normal, transverse, and longitudinal directions. Three different wear conditions were employed for two different periods of time, 24 and 48 hours. The wear track of the worn specimens and the metal counterface was examined with a scanning electron microscope (SEM) to observe the damaged fibers on the surface and wear film generation on the counterface. Wear mechanism of the composite during sliding wear is proposed based on the experimental results.

• World Technopolis Review
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• 제7권1호
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• pp.59-70
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• 2018

Taiwan's economy has been characterized by the strong existence and continuous creation of small and medium-sized enterprises. This phenomenon is commonly regarded to be the result of a culturally embedded strong entrepreneurial spirit. In the process of developing a high-technology industry in southern Taiwan, linking a newly established science park with existing local industries was one of the major challenges. This article reviewed the development history of Tainan Technopolis. Following a concise review of Southern Taiwan Science Park's struggle against becoming an assembly of spillover establishments from Hsinchu Science Park, the authors focused on the efforts of incubating startups. Although only an initial study, the authors demonstrated the roles of National Cheng Kung University and Southern Taiwan Science Park Administration in introducing a two-track incubation system based on collaboration between the two institutions and startups.