• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1254-1261
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• 2011

Application of long-span bridge, which is affected by parameters such as span length, shoe boundary condition, track property and stiffness of superstructure and substructure etc., can vary. Especially, by CWR aspects of the axial force, long-span high speed railway bridges are limited at type and span length. In this study, in terms of CWR axial force, the long-span high-speed railway bridges without REJ(Rail Expansion Joint) is to propose the bridge type. Various Parameters analysis performed for the proposed type(Arch bridge, Cable-stayed bridge).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.69-72
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• 2004

In order to use HTS tape on electric power applications, such as cable, motor, transformer, fault current limiter, a long length of HTS tape with a good uniformity of critical current is inevitable. The longer length of HTS tape, the wider in the range of application and the lower cost of HTS tape. In this study three long length Bi-2223/Ag tapes(268m, 253m and 187m) were fabricated. Critical current uniformity along the length was greatly improved through the optimization of cold deformation and thermo-mechanical process. Average critical current of the tapes was 63.2 A, 54.6 A and 64.2 A, respectively Critical tensile strength and critical bending radius (77 K, 5 % Ic degradation) was 135 MPa and 56 m, respectively.

• Structural Engineering and Mechanics
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• 제37권4호
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• pp.443-458
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• 2011

An extensive numerical investigation on the magnetorheological (MR) damper-based smart passive control system for mitigating vibration of stay cables under wind loads has been conducted. The smart passive system is incorporated with an electromagnetic induction (EMI) device for reducing complexity of the conventional MR damper based semi-active control system by eliminating an external power supply part and a feedback control part (i.e., sensors and controller). In this study, the control performance of the smart passive system has been evaluated by using a cable structure model extracted from a full-scale long stay cable with high tension. Numerical simulation results of the proposed smart damping system are compared with those of the passive and semi-active control systems employing MR dampers. It is demonstrated from the results that the control performance of the smart passive control system is better than those of the passive control cases and comparable to those of the semi-active control systems in the forced vibration analysis as well as the free vibration analysis, even though there is no external power source in the smart passive system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.116-119
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• 2004

The existing monitoring and control systems of utility-pipe conduit (power tunnel, cable tunnel etc) have established communication lines using optical fiber, leaky coaxial cable (LCX), and several kinds of control cable. Due to the properties of the used media, the cost of equipment is considerably high and the maintenance of the system is difficult. Also, the term of carrying out is long so that the extension of the system is in difficulty. Now it is desirable to adopt Power Line Communication (hereinafter, PLC) technology in the monitoring and control systems and use the existing low-voltage power-line for lamplight as communication line. This will lead the reduction of the construction cost and the easy maintenance of the system. In this paper, we research the characteristics of PLC in conduit, design and manufacture the field test system, and analyze the performance of the system by field test. Then, we introduce the reliable monitoring and control system of utility-pipe conduit using PLC.

• 패션비즈니스
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• 제16권3호
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• pp.125-135
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• 2012

Since knitted textile products mostly do not require long span of time from the conception to the final products, they have lead the fashion trends during the recent decades. Developments in the textile engineering industries, and computer software and hardware industries have made the 3D virtual clothing software system easily accessible by the fashion/textile industry personnel. The simulated models of apparel products using the state-of-the-art virtual clothing systems are, however, not the replica of real-world garments. Moreover, the garments do not maintain fixed shapes during wearing. Deformations at low external stress lead to difficulties in predicting the behavior of the knitted garments. Therefore, there is a need to compare the differences in appearances, textures, or other related properties between simulated fabrics and actual fabrics. Three knit stitches including jersey, rib, and cable stitches are examined in this study. The differences between fluffy thick yarns and thin yarns are also compared using 3D scanning and surface reconstruction. Obtained three-dimensional data regarding the reconstructed knit specimens would help to build a data base for estimating the behavior of the 3D models of the knitted garments.

• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.9-16
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• 2017

The performance test is conducted for the purpose of determining the accurate thermal performance of the power generation facility or deriving the factors of thermal efficiency degradation. Compared to the acquisition method of power plant thermal performance test data by compensating cable or transmission cable, performance test using wireless instrument can acquire digital data in order to shorten the period due to installation and demolition of instrument and enhance safety of workers and relatively accurate data can be acquired thereby improving work efficiency. Wireless instruments have already been introduced to the market a long time ago, and some of them are used in industry such as petrochemical industry. However, there is no example which has been conducted for performance test of power generation facilities. In order to apply power generation facilities, a reliable system capable of acquiring performance data smoothly without affecting the control system is required. The wireless measurement system can eliminate the measurement defects and errors such as the damage due to the movement of the connecting cable, the extension due to the extension of the shield wire, the contact failure at the contact point between the measuring sensor and the connecting wire, This method has the advantage of collecting relatively accurate performance test data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.429-431
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• 2003

CCTV network has been implemented to transmit the image information of platform, ticket gate and transfer section to local headquarters in the KNR(Korean National Railroad). But, communication system for transferring image information around accident field or wayside has not been established ret. thus, at Present implementation of communication equipment is necessary for dynamic image of unspecified accident to be transmitted to headquarters. Copper cable communication network is run by KNR, but it is processing installation of optical cable in connection with the implemental plan for high-speed network from now on. And, the capacity of communication channel will be guaranteed much more than now between station and station. station and central headquarters when optical cable is completed. This study analyzes the image equipment of field for transmission and estimated matters to transmit image information of accident field to headquarters with using communication infrastructure. And, the study considers implemental method of communication network for long-distance image transmission from dozens to hundreds kilometers.

• Structural Engineering and Mechanics
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• 제50권2호
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• pp.215-229
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• 2014

Due to the lack of effective longitudinal constraint for center tower, structural stiffness of three-tower suspension bridge becomes less than that of two-tower suspension bridge, and therefore it becomes more susceptible to the seismic action. By taking a three-tower suspension bridge-the Taizhou Highway Bridge over the Yangtze River with two main spans of 1080 m as example, structural dynamic characteristics and seismic performance of the bridge is investigated, and the effects of cable's sag to span ratio, structural stiffness of the center tower, and longitudinal constraint of the girder on seismic response of the bridge are also investigated, and the favorable structural system is discussed with respect to seismic performance. The results show that structural response under lateral seismic action is more remarkable, especially for the side towers, and therefore more attentions should be paid to the lateral seismic performance and also the side towers. Large cable's sag, flexible center tower and the longitudinal elastic cable between the center tower and the girder are favorable to improve structural seismic performance of long-span three-tower suspension bridges.

• Smart Structures and Systems
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• 제10권1호
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• pp.1-14
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• 2012

Given an object, its positioning in the space is a main concern in structural monitoring and a required feedback in structural health monitoring, structural control and robotics. In addition, to make the sensor unit wireless is a crucial issue for advanced applications. This paper deals with the exploitation of wireless transmission technology to long-term monitoring GPS (Global Positioning System) receivers - like the Leica GMX 902 and the Leica GRX 1200-pro. These GPS receivers consist of five parts: antenna, receiver, user client computer, interface and power supply. The antenna is mounted on the object to be monitored and is connected with the receiver by a coaxial-cable through which the radio frequency signals are transmitted. The receiver unit acquires, tracks and demodulates the satellite signals and provides, through an interface which in this paper is made wireless, the resulting GPS raw data to the user client computer for being further processed by a suitable positioning algorithm. The power supply reaches the computer by a wired link, while the other modules rely on batteries re-charged by power harvesting devices. Two wireless transmission systems, the 24XStream and the CC1110, are applied to replace the cable transmission between the receiver and the user client computer which up to now was the only market offer. To verify the performance and the reliability of this wireless transmission system, some experiments are conducted. The results show a successful cable replacement.

• Macromolecular Research
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• 제12권6호
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• pp.545-552
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• 2004

The long-term stability of sulfonic acid-containing polyimides has been investigated. The hydrolytic degradation of homopolyimide and the block copolyimide comprising $27\;mol\%$ of 2,2'-bis(trifluoromethyl)benzidine and $9\;mol\%$ of m-phenylenediamine (BTFMB27mPl0[7/(3+1)]), was quantified through viscosity measurements and FT-IR spectroscopic analyses. The viscosity decrease with respect to time and the degradation rate were similar. The degrees of degradation with respect to time under ambient conditions and at elevated temperature in water were monitored by FT-IR spectroscopy. A new absorption peak was observed at $1786\;cm^{-1},$ which we corresponds to the presence of anhydride end groups formed by hydrolytic scission of the imide rings.