• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.825-829
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• 1993

As a part of the Department of Energy's Environmental Restoration and Waste Management Program, long-reach manipulators are being considered for the retrieval of waste from large storage tanks. Long-reach manipulators may have characteristics significantly different from those of typical industrial robots because of the flexibility of long links needed to cover the large workspace. To avoid structural vibrations during operation, control algorithms employing various types of shaping filters were investigated. A new approach that uses imbedded simulation was developed and compared with others. In the new approach, generation of joint trajectories considering link flexibility was also investigated.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1145-1148
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• 2008

The present status and trend of oxide phosphor thin-film development for thin-film electroluminescent (TFEL) device application are presented in this paper. Recently, several newly developed types of bendable or bendable see-through oxide TFEL lamps have been fabricated using the TFEL technology with a newly developed bendable ceramic sheet, glass sheet or sapphire sheet substrate, which has become available on the market. Stable operation at high temperatures was obtained in double-insulating-layer-type TFEL lamps fabricated with a $Zn_2Si_{0.6}Ge_{0.}4O_4$:Mn thin-film emitting layer forming on translucent or transparent bendable sheet substrates.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.70-74
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• 2018

In order to ensure the flow of goods available and more flexible, reduce labor costs, many factories and industrial zones around the world are gradually moving to use automated solutions. One of them is to use Automated guided vehicles (AGV). Currently, there are a line tracing method as an AGV operating method, and a method of estimating the current position of the AGV and matching with a factory map and knowing the moving direction of the AGV. In this paper, we propose ceiling Light and guided line based moving direction estimation algorithm using multi-camera on the AGV in smart factory that can operate stable AGV by compensating the disadvantages of existing AGV operation method. The proposed algorithm is able to estimate its position and direction using a general - purpose camera instead of a sensor. Based on this, it can correct its movement error and estimate its own movement path.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.422-431
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• 2006

This paper proposes an adaptive routing protocol called ARCA for converged ad-hoc and cellular network (CACN). Due to the limitation of both bandwidth and transmission range in a cell, a mobile host (MH) may not be able to make a call during busy time. CACN offers a flexible traffic diversion mechanism that allows a MH to use the bandwidth in another cell to ease the congestion problem and increase the throughput in a cellular network. Based on the presentation of CACN's physical characteristics, the paper details the design issues and operation of the adaptive routing protocol for CACN (ARCA). Detailed numerical analysis is presented in terms of both route request rejection rate and routing overhead, which, along with the simulation results, have indicated the effectiveness and efficiency of the ARCA protocol.

• Proceedings of the KIEE Conference
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• summer
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• pp.15-17
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• 2004

The flexible AC transmissions system (FACTS) is the underpinning concept upon which are based promising means to avoid effectively power flow bottlenecks and ways to extend the loadability of existing power transmission networks. This paper proposes a method by which the optimal locations of the FACTS to be installed in power system under cost function. The optimal solution of this type of problem requires large scale nonlinear optimisation techniques. We used Lagrange multipliers to solve a nonlinear equation with equality and ineaquality constraints. Case studies on the standard IEEE 14 bus system show that the method can be implemented successfully and that it is effective for determining the optimal location of the FACTS

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.23-25
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• 2000

In recent deregulation and competitive power market environment, electric utilities plan and operate their systems for economic benefit with secure system condition. Flexible AC transmission system(FACTS) technology opens up new opportunities of controlling power and enhancing the usable capacity of present transmission system. This paper presents a method for security constrained optimal allocation of FAETS considering contingencies for the purpose of enhanced system operation. The proposed scheme uses Benders decomposition to account of both corrective and preventive mode.

• The KSFM Journal of Fluid Machinery
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• v.5 no.1 s.14
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• pp.55-61
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• 2002

The feasibility of an oil-free, motor-driven, two-stage centrifugal compressor supported by air bump bearings is investigated. This centrifugal compressor is driven by a 75 kW motor at an operating speed of 39,000 RPM, and a pressure ratio of the compressor is set up to 4. The analysis is performed by using bearing equilibrium position, heaving stillness, Campbell diagram, unbalance response, and stability. It is demonstrated in this paper that air bump bearings can be adopted well to an oil-free, motor-driven, centrifugal compressor. Specially, Cu-coated bump bearings have enough damping force to reduce a synchronous unbalance for rigid modes of the two-stage compressor. Futhermore, this concept may be applied to the flexible rotor system such as high speed turbomachinery with a super critical speed.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.68.5-68
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• 2002

For the performance test of rechargeable electric tools, it is necessary to test under the same condition as the actual operation condition. They are necessary to control the load torque and to acquire the test data with a computer, and it should be convenient to fix the tool on the test equipment for rechargeable electric tools. It consists of torque loading parts, sensing parts and control software. Two hysteresis brakes, connected serially with flexible coupling, were applied to control the load for the test. The sensing part consists of a torque sensor, a rpm detector and a power analyzer. The torque and the rpm were measured in order to calculate the output of the rechargeable electric...

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.1
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• pp.42-48
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• 1988

MM(multimode) PWM(pulse width modulation) Suitable for high performance and harmonic effects minimization of VSI (voltabge source invertetr)-IM (induction motor)drive system is proposed. The approximated optimal, suboptimal and optimal PWM are implemented in the low frequency range, while square wave operation is realized in the hibh frequency range. The pulse width Modulator is capable of generating control signals to a transistorized inverter operating at about 1KHz. All functions except digital comparison have been implemented in softyware making the scheme economical, flexible and reliable. Pulse width modulator is built and tested experimentally. In order to confirm the effectiveness and the reliability of the theoretical proposition, this scheme is applied to 1Hp, Three phase IM. As results, it is concluded that the scheme of MM PWM is superior to other conventional switching scheme through the discussions or analysis carried out on the items such as line-to-line voltage, current and spectrum of current harmonic components observed at the output terminal of inverter, noise level of motor.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1034-1037
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• 2002

A switched-capacitor(SC) type DC-DC converter having capability of integrated circuit fabrication have been marked for the application of mobile equipments. Especially, a ring type SC power supply is featured by the flexible and dynamic voltage conversion ratio change. In this paper, an improvement of the gate driving techniques is proposed for high power efficiency and less area occupation on the chip. Furthermore, its power-saving operation in the stand-by state is proposed. The three-capacitors ring type power supply is really designed and discussed. As results, the simulation results shows the high efficiency of 92.1%, and the higher output put voltage of 10.5 V compared with conventional one of 8.6 V.