• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.7
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• pp.399-406
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• 2000

We propose an nonlinear demodulation algorithm for undersampled multicomponent AM(Amplitude Modulation), FM(Frequency Modulation) and AM-FM signals. First, we derive respectively undersampling frequency of the AM, FM and AM-FM using undersampling scheme, and separate respectively monocomponent signals from multicomponent signals using periodic algebraic separation algorithm. In this case augmented separation matrix is very regular and sparse, it has a special structure. The proposed demodulation algorithm detects respectively message signals of the IA(Instantaneous Amplitude) and IF(Instantaneous Frequency) from descrete monocomponent AM, FM and AM-FM signals with an undersampling frequency to be controllable. Verifying the RMS(Root Mean Squares) errors of the detected signals, we show that the performance is excellent.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.682-685
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• 2000

In this paper, Using CDM(Coefficient Diagram Method), we set target polynomial constraints and design 4-PID controller which have different structures such as Textbook PID-controller, Derivative of output PID-controller, set point of I only controller(I-PD controller) and PI controller followed by lag network(PI lag network controller) were tested by simulations. The plant we used are that used in IFAC 93 benchmark test. A controller designer, using CDM could use these results to select the controller's structure which is the best one fer him.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.760-763
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• 2002

Nanoparticle size of Titanium dioxide thin films was prepared by novel method. Particle size and surface structure of $TiO_2$ thin films were investigated by atomic force microscopy(AFM), scanning electron microscopy(SEM). All thin films process were prepared at room temperature. Particle size was reduced from 100 to 30nm with increasing amount of $Ti[OCH(CH_3)_2]_4$ observed by AFM images. All thin films were irradiated for 5 minutes by white light. Increasing the annealing temperature, particles size was increased. In the $TiO_2$(40%) thin films was annealed at $300^{\circ}C$ for 30minutes, the particle size was about 10nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.756-759
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• 2002

Nanoparticles of titanium dioxide$(TiO_2)$ were prepared by photochemical synthesis. Surface structure, morphology and particle size of $TiO_2$ thin films were investigated by UV-VIS spectrophotometer, scanning electron microscopy(SEM) and transmission electron microscopy(TEM). All process was prepared at room temperature. The absorption peak of the films was showed at 360nm and $TiO_2$ nanopaticle size was observed at about 20~30nm. Electron diffraction ring patterns of $TiO_2$ nanoparticles and crystallographic spacing were observed by TEM. As a result, crystallographic spacing was about 3.6A in HR-TEM micrographs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1140-1143
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• 2002

This work describes the effect of conducting composite on the characteristics of electric double layer capacitor. The cell, which was fabricated with conducting composite consisted of 50 wt.% of SPB and 50 wt.% of VGCF, exhibits the higher specific capacitance, the lower resistance and the better rate capability than those of the cells fabricated with each single electronic conductor. These enhanced properties could be related with the dense structure of electrode.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2821-2823
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• 2005

When we deal with the image data through camera lens, much works are necessary for removing image distortions and obtaining accurate informations from the raw data. However, the calibration process is very complicated and requires many trials and errors. In this paper, 3 new approach to image processing is presented by developing a H/W vision system with a tracking camera. Using motor control with encoders the proposed tracking method tells us exact displacements of a moving object. Therefore this method does not require any calibration process for pin cusion. Owing to the mobility one camera covers wide ranges and, by lowering its height, the camera also obtains high resolution of the image. We first introduce the structure of the motion analysis system. Then the construced vision system is investigated by some experiments.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.93-95
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• 2005

When a control system is designed computer simulations are important because they provide a way to test the performances of the control law and determine some design parameters of the control system. Since most real situations are different from those of the simulations, however, it is required to manage uncertainties of the plant and analyze errors fast and correctly. For this we consider a convenient monitoring system which can display real systems responses exactly and check the performances of the control systems. In this paper, an approach to design a monitoring system is presented by using C++Builder program which is based on PC. Firstly we introduce the structure and functions of the monitoring system. Then, an inverted-pendulum control system is investigated by using the monitoring system.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.123-124
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• 2014

본 논문에서 제안하는 Asymmetric 암 구조를 가지는 단상 멀티레벨 인버터는 양방향 스위치를 사용하여 (4m-2)개의 스위치로 n-레벨의 출력 전압을 생성한다. m은 A 암의 전압원수이다. 본 토폴로지는 A 암과 B 암을 형성하는 각각의 커패시터 전압원의 수가 동일하지 않는 것이 특징이다. 이러한 비대칭 전압원 구조의 조합으로 출력 전압 레벨 수를 최대화한다. 제안된 Asymmetric 암 구조를 가지는 단상 멀티레벨 토폴로지는 PSIM 시뮬레이터를 통해 11-레벨로 구현하여 타당성을 검증하였다.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.2
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• pp.8-17
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• 2012

Three kinds of cationic acrylamide copolymer with different branch degree were prepared controlling the dosage of N, N'-methylenebisacrylamide. The physical characteristics of the branch-degree-modified copolymers were analyzed by intrinsic viscosity and charge density. The branch degree measurements were investigated by applying the colloidal titration phenomena using a spectrophotometer and comparison with the cationic regain measurement method. The results showed that the absorbance behaviors of spectrophotometer were distinctively different with the branch degree of copolymers. Also, the branch degree determinations and molecular structure estimations of the copolymers were numerically measured by applying the titration phenomena using a spectrophotometer. Finally, three kinds of branch-degree-modified copolymers were applied to flocculation test using arbocel micro pulp for the determination of flocculation behavior by different morphology of cationic acrylamide copolymers.

• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.272-277
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• 2011

The effect of the M-window color mixing bar on the characteristics of color mixing and hot spots in the edge-lit backlight employing red (R), green (G), blue (G) light emitting diodes (LED) were studied in terms of the structure of the M-window color mixing bar. The rays from RGB LEDs entering the M-window bar were mixed by internal reflection and scattering inside the M-window bar so that the hot spots and color separation were minimized. The M-window bar was designed and fabricated and the simulation results are matched quite well to experimental data.