• Journal of Navigation and Port Research
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• v.28 no.9
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• pp.803-808
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• 2004

In this paper, an INS compensation algorithm is proposed using the accelerometer from IMU. First, we denote the basic INS algorithm and show that how to compensate the position error when low cost IMU is used. Second, considering the ship's characteristic and ocean environments, we consider with a drift as a periodic external environment change which is affected with exact position. To develop the compensation algorithm, we use a repetitive method to reduce the external environment changes. Lastly, we verify the proposed algorithm through the experiments, where the acceleration sensor is used to acquire real data.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1172-1175
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• 2001

Recently, vector control without a speed sensor for an inverter induction motor system has been developed. In this paper describes the vector control system estimates rotor speed based on FMRAS(Flux Model Reference Adaptive System). Because of improving the initial condition and drift problem by pure integrator is eliminated, we can be expected to rapid responsibility of the speed estimation. The stability of speed estimator is proved on the basis of hyperstability theory. Proposed control system used TMS320C31 DSP for high speed processing. The effectiveness of the proposed system is verified by simulation and experimental results. This result shows that the highly characteristic speed estimation and robust character of load regulation.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.10
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• pp.727-732
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• 2004

TCXO is one of the most important component in communication systems. We present a analytic method approach to design the Temperature Compensated Circuit. The conventional method for extracting the circuit parameters, which are for thermistor, Colpitts and frequency control circuit is the trial and error correction. In this paper, we analyse the temperature compensating circuit to extract TCXO circuit parameter. In order to show the validity of this paper, we have designed and implemented the 10MHz TCXO. The fabricated TCXO shows 1ppm frequency drift characteristic over the temperature range of -40℃∼85℃.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.2
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• pp.23-29
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• 2014

Less power consumption, lower cost, smaller size and more functionality are the increasing demands for consumer electronic devices. The three dimensional(3-D) TSV packaging technology is the potential solution to meet this requirement because it can supply short vertical interconnects and high input/output(I/O) counts. Cu(Copper) has usually been chosen to fill the TSV because of its high conductivity, low cost and good compatibility with the multilayer interconnects process. However, the CTE mismatch and Cu ion drift under thermal stress can raise reliability issues. This study discribe the thermal stress reliability trend for successful implementation of 3-D packaging.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.9
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• pp.1201-1208
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• 2001

Variable temperature anemometer(VTA) has greater sensitivity than a conventional constant temperature anemometer(CTA). In order to design a reliable VTA system, however, an elaborate photoconductive cell stabilizing circuit which plays a key role in setting wire-overheat ratio should be firstly developed. In this study, a stabilizing circuit which adopts proportional-integral analog controller was proposed and thoroughly tested for its accuracy and reproducibility. In contrast to the available circuit suggested by Takagi, the present circuit has characteristic that the resistance of a photoconductive cell increases with the increase of input voltage, which makes the current circuit very suitable for the design of VTA. Finally, VTA adopting stabilizing circuit was made and the enhanced sensitivity of the VTA was validated experimentally by comparing the calibration curves of VTA and CTA.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.435-438
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• 1997

One of the main techniques or diagnosing heart disease is by examining the electrocardiogram(ECG). Many studies on detecting the QRS complex, P, and T waves have been performed because meaningful information is contained in these parameters. However, the earlier detecting techniques can not effectively extract those parameters from the ECG that is severely contaminated by noise source such 60Hz powerline interference, motion artifact and baseline drift. in this paper, we performed the extracting parameters from and recovering the ECG signal using wavelet transform that has recently been applying to various fields.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.2
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• pp.104-111
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• 2003

Micro force measurement is required more frequently for a precision manufacturing and investment in fields of precision industries such as semiconductor, chemistry and biology, and so forth. Null balance method has been introduced as an alternative of a loadcell. Loadcells have advantages in aspects of low cost and easy manufacturing, but have also the limitation in resolution and sensitivity to environment variations. In this paper, null balance method is explained and the dominant parameters related to system performances are mentioned. Null position sensor, electromagnetic system and controller are investigated. Also, the characteristic experiment is carried out in order to estimate the resolution and the measurement range. In order to overcome the limitation by the drift of position sensor and the performance of controller, double electromagnetic force compensation method is proposed and experimented. After controlling and filtering, the resolution under $\pm$ 1mg and measurement range over 300g could be obtained.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.29
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• pp.3-37
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• 2006

This writing is for the purpose of investigating the specific character and problem point of China arbitration system which has near 90 years history and overviewing the drift of system improvement which happens recently. The arbitration system of China which traditionally does not acknowledge ad hoc arbitration, unlike most of the other nations that employ The UNCITRAL model law and make it their own legislation, is restrictive to the parties concerned principle of private autonomy considerably. Also the independence of arbitration is delicate, because of a civil characteristic weakness of the arbitral institutions and the intervention of the courts on the arbitration procedure and award. The dual system of domestic and international arbitration which maintains after enforcement of 1994 arbitration law is often to be a primary factor interrupting the development of Chinese arbitration system and making it vulnerable to challenges. The system improvement demand of the recent time reflects this point and makes the arbitration system of China to a international standard rather than now, so it is a desirable direction for China to be as the member of the world economy to be globalization.

• Journal of IKEEE
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• v.19 no.4
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• pp.465-471
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• 2015

An LC-tuned sinusoidal voltage-controlled oscillator (VCO) using temperature-stable linear operational transconductance amplifiers (OTAs) is presented. Its architecture is based on Hartley oscillator configuration, where the inductor is active one realized with two OTAs and a grounded capacitor. Two diode limiters are used for limiting amplitude. A prototype oscillator built with discrete components exhibits less than 3.1% nonlinearity in its current-to-frequency transfer characteristic from 1.99 MHz to 39.14 MHz and $220ppm/^{\circ}C$ frequency stability to the temperature drift over 0 to $75^{\circ}C$. The total harmonic distortion (THD) is as low as 4.4 % for a specified frequency-tuning range. The simulated phase noise of the VCO is about -108.9 dBc/Hz at 1 MHz offset frequency in frequency range of 0.4 - 46.97 MHz and property of phase noise of VCO is better than colpitts-VCO.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.165-168
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• 1999

The electron transport coefficients in mixture gas includes SF/sub 6/ is analysed in range of E/N values from 60∼800(Td) by the Boltzmann method that using a set of electron collision crass sections determined by the researchers. Swarm parameters in the Boltzmann method simulation such as electron drift velocity, ionization and electron attachment coefficients is in nearly agreement with the respective experimental and theoretical for a range of E/N.