• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.152-155
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• 1994

The presence of joint elasticity or the arm flexibility causes low damped oscillatory position error along a desired trajectory. We utilize a stochastic model for describing the fast dynamics and the approximation error. A second order shaping filter is synthesized such that its spectrum matches that of the fast dynamics. Augmenting the state vector of slow part with that of shaping filter, we obtain a nonlinear dynamics to which a Gaussian white noise is injected. This modeling approach leads us to the design of an extended Kalman filter(KEF) and a linear quadratic Gaussian(LQG) control scheme. We present the simulation results of this control method. The simulation results show us that our Kalman filtering approach is one of prospective methods in controlling the flexible arms.

• International Journal of Control, Automation, and Systems
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• 제1권4호
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• pp.412-430
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• 2003

In many practical problems in signal processing and control, the signal values are often restricted to belong to a finite number of levels. These questions are generally referred to as "finite alphabet" problems. There are many applications of this class of problems including: on-off control, optimal audio quantization, design of finite impulse response filters having quantized coefficients, equalization of digital communication channels subject to intersymbol interference, and control over networked communication channels. This paper will explain how this diverse class of problems can be formulated as optimization problems having finite alphabet constraints. Methods for solving these problems will be described and it will be shown that a semi-closed form solution exists. Special cases of the result include well known practical algorithms such as optimal noise shaping quantizers in audio signal processing and decision feedback equalizers in digital communication. Associated stability questions will also be addressed and several real world applications will be presented.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.342-345
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• 2004

A combination of deep drawing and cold forging process is tried to achieve near net shaping of automatic transmission part which has drum shape and thickness variation. It is key for successful shaping of the part to find out proper condition to combine two different forming methods. Finite element analysis can be utilized for that purpose effectively. Integrity, reliability, and durability of the part are improved by eliminating machining process. The developed process is applied in real manufacturing process successfully.

• 한국주조공학회지
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• 제23권1호
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• pp.47-51
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• 2003

This experimental study was carried out to investigate the solidification characteristics of polystyrene added styronaphthalene pattern materials using various castability test methods. The styronaphthalene showed an excellent filling capacity and shaping behavior having about 0.2 mm meniscus radius. The shell thickness of styronaphthalene showing smooth wall at the solid/liquid interface increased with the increasing of polystyrene addition. The solidification microstructure of styronaphthalene showed a typical thin ribbon reinforced composite structure, which has fibrous amorphous skeleton of polystyrene and crystalline naphthalene. From the results of this study, it was found that the polystyrene added styronaphthalene showed a precision shaping behavior as disposable pattern material under the atmospheric condition.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권4호
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• pp.415-424
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• 2016

This paper describes a high data rate proximity transmitter design for high resolution smartphone-mirrored display applications. A 2 Gb/s transmitter is designed with a low transmission power of -70 dBm/MHz and a wide bandwidth of nearly 3 GHz. A digital pre-correction method is employed in the transmitter to mitigate the inter-symbol interference problem. A carrier-based digital pulse shaping and a reconfigurable digital envelope generation methods are employed for robust operation by utilizing 20 phases from a 2 GHz phase-locked loop. A 6.5-9.5 GHz transmitter implemented in 65 nm CMOS achieves the maximum data rate of 2 Gb/s, consuming only 7.6 mW from a 1 V supply.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2002년도 춘계학술대회논문집
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• pp.161-176
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• 2002

Collision avoidance is the most important part of a small vessel. Small and mediurn sized ships are surprisingly poor targets for radar reflection and are frequently in danger of being overrun by large vessels, even under good condition of visibility. One of the best way to prevent collisions at sea is to use as large and well designed a radar reflector. Thus, RCS(Radar Cross Section) increase is key element in the design of radar reflector. Radar Reflectors are normally classified into active-type and passive-type. In this paper, the RCS increase methods for passive-type reflector through shaping are explained, and analyzed with RCS performance test by computer simulation. As results from analysis, It is shown that the effective diameter of radar reflector is over 10 λ to provide a return above the threshold RCS of 25m$^2$, lower limit of detectability using X-band radar in a moderate sea.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.263-266
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• 2002

Many methods have been Proposed to reduce the PAPR of the OFDM signal. Among them a method that uses the time waveform of the different sub-carriers. The method is referred to as pulse shaping and it works with arbitrary number of sub-carriers and my type of base-band linear modulation. It has been shown, using this technique, that it is possible to design a set of time waveforms that reduce the PAPR of the OFDM transmitted signal and improve its power spectrum simultaneously. In this paper, we investigate the effect of some of these sets of time waveforms on the OFDM system performance in terms of Bit Error Rate (BER).

• 한국소음진동공학회논문집
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• 제18권1호
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• pp.3-10
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• 2008

In this paper, the optimal command input is considered in order to minimize the residual vibrations of a flexible cantilever beam when the beam simply changes its position by translation or rotation. Although a cantilever beam has many modes of vibration, it is shown that the consideration of the first mode is sufficient in this case. Thus, the problem becomes a single-degree-of-freedom system subjected to a ground excitation. Two simple methods are proposed to find the optimal command input based on the shock response spectrum (SRS). The first method is the simplest and can be applied to lightly damped cases, and the second method is applicable to more general problems. The second method gives almost the same results as the input shaping method. However the proposed method gives a easier and clearer control strategy.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.554-554
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• 2003

I. Objectives This study was done to evaluate the shaping ability of ProFile and ProTaper, K-Flexofile during instrumentation in simulated resin canals with different angles of curvature. II. Materials and Methods Ninety simulated root canals with a curvature of 15, 30 and 45 degree (following Schneider's method) were made of epoxy resin ($EPOXICURE^{TM}$, BUEHLER, USA) for this study. The canal length of simulated root canals was adjusted to 18 mm. The beginning point of curvature was positioned at 10mm from the canal orifice.(omitted)

• 대한전자공학회논문지
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• 제12권6호
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• pp.21-30
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• 1975

본 논문에서는 복소함수에 대한 최적설계 이론을 제안하여 연산회로, 파형성형회로, 여파기, 증폭기, 전송선로 등의 설계에 적용하여 본 결과, 실험치와도 잘 일치하였으며, 복소함수의 두가지 요소인 절대치와 위상을 동시에 고려한 회로망의 최적설계를 가능하게 하였으며, 또 여러 가지 상이한 회선정수를 포함하는 경우라도 설계가능하도록 무게함수의 선정 방법을 제시하였다. A method by which one can optimize the complex responses of electronic circuits has been suggested. represented in the complex forms, the optimization methods presented so far have dealt with real magnitude and phase responses of circuits. Design examples are shown on the optimal designs of an amplifier, filter, operational circuits transmission lines. and a wave-shaping circuit.