• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.783-786
• /
• 1998

We designed a 3.3 V, 400 Mbps IEEE-1394 physical layer transeiver on 0.6um 1P3M CMOS process. The transceiver drives a twisted pair cable of which differential impedance is 110 $\Omega$ so that differential amplitude reaches 200 mV at 400 Mbps and restores this small signal to rail-to-rail. Also, the transceiver arbitrates the interface among nodes on a bus configuration and supports both synchronous interface and asynchronous interface.

• Structural Engineering and Mechanics
• /
• 제90권4호
• /
• pp.325-343
• /
• 2024

Triple-tower double-cable suspension bridges have increased confinement stiffness imposed by the main cable on the middle tower, which has bright application prospects. However, vertical bending and torsional vibrations of the double-cable and the girder are coupled in such bridges due to the hangers. In particular, the bending vibration of the towers in the longitudinal direction and torsional vibrations about the vertical axis influence the vertical bending and torsional vibrations of the stiffening girders, respectively. The conventional analytical algorithm for assessing the dynamic features of the suspension bridge is not directly applicable to this type of bridge. This study attempts to mitigate this problem by introducing an analytical algorithm for solving the triple-tower double-cable suspension bridge's natural frequencies and mode shapes. D'Alembert's principle is employed to construct the differential equations of the vertical bending and torsional vibrations of the stiffening girder continuum in each span. Vibrations of stiffening girders in each span are interrelated via the vibrations of the main cables and the bridge towers. On this basis, the natural frequencies and mode shapes are derived by separating variables. The proposed algorithm is then applied to an engineering example. The natural frequencies and mode shapes of vertical bending and torsional vibrations derived by the analytical algorithm agreed well with calculations via the finite element method. The fundamental frequency of vertical bending and first- and second-order torsion frequencies of double-cable suspension bridges are much higher than those of single-cable suspension bridges. The analytical algorithm has high computational efficiency and calculation accuracy, which can provide a reference for selecting appropriate structural parameters to meet the requirements of dynamics during the preliminary design.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.153-158
• /
• 2004

In this paper, we proposed a two-stage control of the container crane. The first stage control is time-optimal control for the purpose of fast trolley traveling. With suitable trolley velocity patterns, the sway which is generated during trolley moving is minimized. At the second stage control feedback control law is investigated for the quick suppression of residual vibration after the trolley motion. For more practical system, the container crane system is modeled as a partial differential equation (PDE) system with flexible cable. The dynamics of the cable is derived as a moving system with tension caused by payload using Hamilton's principle for the systems. A control law based upon the Lyapunov's method is derived. It is revealed that a time-varying control force and a suitable passive damping at the actuator can successfully suppress the transverse vibrations.

• 조명전기설비학회논문지
• /
• 제21권10호
• /
• pp.181-189
• /
• 2007

본 논문에서는 전기철도에서 발생하는 대지전위와 통신회선의 잡음에 대한 실험적 증명에 관한 것이다. 대지전위차가 발생하는 곳에서 전력유도잡음전압과 케이블 평형도 등을 측정할 경우 계측 오차가 심각하게 발생되는 것으로 나타났다. 측정결과, 고속철도 인접한 곳의 통신케이블은 시스층에 지전류가 많이 흐르는 차폐 케이블보다 일반 케이블을 그대로 사용하는 것이 잡음피해를 보다 줄일 수 있음이 실험 결과로 확인 되었다.

• 한국생산제조학회지
• /
• 제20권6호
• /
• pp.751-755
• /
• 2011

Electric Parking Brake(EPB) is the system operated by electric control actuator. It differs from the mechanical parking brake system which is operated by lever and pedal in need of human power. The EPB system is composed of DC motor, helical and differential epicyclic gear, screw, cables, and sensor. This paper describes about the EPB system mathematically and constructs a modeling of the EPB system using MATLAB/SIMULINK. Especially, SimMechanics library in SIMULINK is used to make each parts of system a module. By made modeling of the friction torque between bolt and nut. Cable tension can be maintained after the motor operating stops.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.2140_2141
• /
• 2009

We used the eddy current sensor for a 22.9kV distribution power line insulation cable diagnosis. The insulation cable which is used in the 22.9kV distribution power line is having element wire from 6 to 18. Consequently, currently to ECT applications it has a limit in the distribution power line. We about under producing to apply in pick-up coil forms and the differential total coil form where becomes sum of zero in order to have. From measurement result, partial broken cable was confirmed 500 mV~980 mV changes from normal state.

• Computers and Concrete
• /
• 제2권2호
• /
• pp.125-146
• /
• 2005

The objective of this paper is setting out, for a cable-stayed bridge with a curtain suspension, a method to determine the modes of vibration of the structure. The system of differential equations governing the vibrations of the bridge, derived by means of a variational formulation in a nonlinear field, is reported in Appendix C. The whole analysis results from the application of Hamilton's principle, using the expressions of potential and kinetic energies and of the virtual work made by viscous damping forces of the various parts of the bridge (Monaco and Fiore 2003). This paper focuses on the equation concerning the transversal motion of the girder of the cable-stayed bridge and in particular on its final form obtained, restrictedly to the linear case, neglecting some quantities affecting the solution in a non-remarkable way. In the hypotheses of normal mode of vibration and of steady-state, we propose the resolution of this equation by a particular method based on a numerical approach. Respecting the boundary conditions, we derive, for each mode of vibration, the corresponding frequency, both natural and damped, the shape-function of the girder axis and the exponential function governing the variability of motion amplitude in time. Finally the results so obtained are compared with those deriving from the dynamic analysis performed by a finite elements calculation program.

• 한국초전도ㆍ저온공학회논문지
• /
• 제20권3호
• /
• pp.28-33
• /
• 2018

With the continuous performance improvement and commercialization of HTS wires, there have been many efforts to commercialize HTS power cables recently. Unlike conventional power cables, a cryogenic cooling system is required for a HTS power cable and a cryogenic pump is one of the essential components to circulate subcooled liquid nitrogen and cool the HTS power cable. Especially, the development of a reliable and high-efficiency cryogenic pump is an important issue for the commercialization of HTS power cables of several kilometers or more. In this study, we designed and fabricated a cryogenic pump for subcooled liquid nitrogen with a mass flow rate of 1.2 kg/s, a differential pressure of 5 bar, and evaluated the hydraulic performance of the pump. Impeller design was conducted to meet the target design performance with 1 D analysis model and CFD analysis. The pump performance parameters such as pressure heads, mass flow rates, and efficiencies in accordance with rotating speeds were assessed using a laboratory's performance evaluation system.

• 한국전자파학회논문지
• /
• 제28권11호
• /
• pp.872-879
• /
• 2017

본 논문은 direct digital synthesizer, 연산 증폭기 및 이득/위상 검출기로 구성된 소형 임피던스 분석기를 사용하여 차분 주파수 영역 반사 계측을 기반으로 한 케이블 결함 모니터링 시스템을 제시한다. 제안된 시스템은 주파수 영역 반사계측을 위한 고가의 벡터 네트워크 분석기를 저비용으로 대체할 수 있으므로, 장기간 동안 다중 지점을 모니터링하는 센서 네트워크 구성이 가능하다. 이 시스템의 성능은 전원 케이블의 결함 지점을 진단하는 실험을 통해 검증하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
• /
• pp.138-141
• /
• 2004

In this paper, we Investigated effects on impurities and water of semiconductive shield through a thermal, mechanical, and absorption experiment to estimate performance of insulating materials in power cable. Specimens had been prepared 22[kV], 154[kV] XLPE power cables and then were made of sheet form with XLPE and semiconductive shield with dimension of 0.4[mm] ~1.2[mm] of thickness from power cable. Heat capacity $({\Delta}H)$ and glass trasition temperature (Tg) of XLPE sheet were measured by DSC (Differential Scanning Calorimetry). We could know that thermal stabilities of 154[kV] are more excellent than 22[kV] from this experimental result. The strain of mechanical properties in 22[kV] and 154[kV] XLPE was 486[%], 507[%] and stress was 1.74$[kgf/mm^2]$, 1.80$[kgf/mm^2]$. The absorption contents of existing semiconductive shield were measured 710[ppm] to 1,090[ppm], and semiconductive shield of 22[kV] cable was measured 14,750[ppm] to 24,780[ppm]. We thermal and mechanical properties of 154[kV] could know more excellent than 22[kV] from this experimental result.