• Journal of Korea Society of Industrial Information Systems
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• v.11 no.2
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• pp.40-47
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• 2006

The learning control develops controllers that learn to improve their performance at executing a given task, based on experience performing this specific task. In a previous work the authors presented an iterative precision of linear decentralized learning control based on p-integrated teaming method for the vertical dynamic multiple systems. This paper develops an indirect decentralized learning control based on adaptive control method. The original motivation of the loaming control field was learning in robots doing repetitive tasks such as on a]1 assembly line. This paper starts with decentralized discrete time systems, and progresses to the robot application, modeling the robot as a time varying linear system in the neighborhood of the nominal trajectory, and using the usual robot controllers that are decentralized, treating each link as if it is independent of any coupling with other links. Error wave propagation method will show up in the numerical simulation for five-bar linkage as a vertical dynamic robot. The methods of learning system are shown up for the iterative precision of each link at each time step in repetition domain. Those can be helped to apply to the vertical multiple dynamic systems for precision quality assurance in the industrial robots and medical equipments.

• Smart Structures and Systems
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• v.20 no.3
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• pp.273-283
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• 2017

This paper presents and compares three feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity. These are a) control strategy based on direct output feedback (DOFB) b) control strategy based on linear quadratic regulator (LQR) to reduce structural vibrations and c) LQR control strategy with a weighting scheme based on structural-acoustic coupling coefficients. The first two strategies are indirect control strategies in which noise reduction is achieved through active vibration control (AVC), termed as AVC-DOFB and AVC-LQR respectively. The third direct strategy is based on active structural-acoustic control (ASAC). This strategy is an LQR based optimal control strategy in which the coupling between the various structural and the acoustic modes is used to design the controller. The strategy is termed as ASAC-LQR. A numerical model of a 3-D rectangular box cavity with a flexible plate (glued with piezoelectric patches) and with other five surfaces treated rigid is developed using finite element (FE) method. A single pair of collocated piezoelectric patches is used for sensing the vibrations and applying control forces on the structure. A comparison of frequency response function (FRF) of structural nodal acceleration, acoustic nodal pressure, and piezoelectric actuation voltage is carried out. It is found that the AVC-DOFB control strategy gives equal importance to all the modes. The AVC-LQR control strategy tries to consume the control effort to damp all the structural modes. It is seen that the ASAC-LQR control strategy utilizes the control effort more intelligently by adding higher damping to those structural modes that matter more for reducing the interior noise.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2611-2613
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• 2002

본 논문에서는 전력선 통신 채널의 간접 잡음 측정에 대한 연구를 하였다. 주위 환경에 의한 Noise 및 여러 통신매체에 의한 방해전파에 의해 전력선 통신 채널은 송신 측의 고출력 요구와 가능한 전력선 통신의 대역폭이 감소하는 악화된 통신환경을 보여 준다. 이러한 Noise를 측정하는 방법은 Coupling Capacitor를 이용한 직접 측정 방식과 이동 측정 장치를 이용한 간접 측정 방식이 있다. 전자는 광범위한 측정지역과 측정장비의 설치 등에서의 번잡함으로 효과적인 Noise 측정이 어렵다. 본 논문에서는 두 가지 방식의 Noise 측정 결과의 비교 및 검토를 통해 이동 측정 장치를 이용한 방식의 장점과 보완할 점을 검토였으며, 특히 직접 측정 방식과의 결과 값의 차이를 보상할 수 있는 상관관계 분석의 필요성을 고찰하였다.

• 전기의세계
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• v.28 no.6
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• pp.61-77
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• 1979

This paper is concerned with minimization process of the binary logic function. This paper describes an algorithm called the SIMPLE TABLE METHOD that well suited to minimization a switching function of any number of variables. For the Simple Table construction, a theorem based upon the numerical properties of the logic function is derived from the relationships governing minterms of the given function. Finally the minimal sum of products can be obtained in terms of the Direct Method or the Indirect Method from the table and table characteristics derived from the Simple Table. The properties and table characteristics used in this paper are described. All the minterms of a switching function are manipulated only by decimal numbers, not binary numbers. Some examples are used as a vehicle to guide the readers who are familiar with the Karnaugh map and Quine-McCluskey tabular method to this New method. These examples not only treat how to handle Don't Care miterms but also show the multiple output functions.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.171-178
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• 2001

A Purge and Trap Concentrator has been used to analyze various volatile organic compounds in water, operating several parameters affecting the extraction efficiencies of these compounds. The object of the present study was to observe the purge efficiencies of 40 volatile organic compounds (VOCs) in water, according to the change of parameters (purge time, dry purge time, sample temperature), and to determine the optimum condition of analysis of VOCs. The Purge and Trap Concentrator was interfaced with a narrow capillary connected to a gas chromatography mass spectrometer. At this condition, the detection limits of VOCs were in the range of 0.1-0.5 ㎍/L.

• Wind and Structures
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• v.27 no.1
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• pp.11-27
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• 2018

The straight-cone steel cooling tower is a novel type of structure, which has a distinct aerodynamic distribution on the internal surface of the tower cylinder compared with conventional hyperbolic concrete cooling towers. Especially in the extreme weather conditions of strong wind and heavy rain, heavy rain also has a direct impact on aerodynamic force on the internal surface and changes the turbulence effect of pulsating wind, but existing studies mainly focus on the impact effect brought by wind-driven rain to structure surface. In addition, for the indirect air cooled cooling tower, different additional ventilation rate of shutters produces a considerable interference to air movement inside the tower and also to the action mechanism of loads. To solve the problem, a straight-cone steel cooling towerstanding 189 m high and currently being constructed is taken as the research object in this study. The algorithm for two-way coupling between wind and rain is adopted. Simulation of wind field and raindrops is performed with continuous phase and discrete phase models, respectively, under the general principles of computational fluid dynamics (CFD). Firstly, the rule of influence of 9 combinations of wind sped and rainfall intensity on flow field mechanism, the volume of wind-driven rain, additional action force of raindrops and equivalent internal pressure coefficient of the tower cylinder is analyzed. On this basis, the internal pressures of the cooling tower under the most unfavorable working condition are compared between four ventilation rates of shutters (0%, 15%, 30% and 100%). The results show that the 3D effect of equivalent internal pressure coefficient is the most significant when considering two-way coupling between wind and rain. Additional load imposed by raindrops on the internal surface of the tower accounts for an extremely small proportion of total wind load, the maximum being only 0.245%. This occurs under the combination of 20 m/s wind velocity and 200 mm/h rainfall intensity. Ventilation rate of shutters not only changes the air movement inside the tower, but also affects the accumulated amount and distribution of raindrops on the internal surface.

• Korean Journal of Environmental Agriculture
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• v.13 no.1
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• pp.76-82
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• 1994

A competitive indirect enzyme-linked immunosorbent assay(ELISA) was developed to detect and quantify levels of the fungicide metalaxyl in crops. Antiserum against metalaxyl was demonstrated in rabbits immunized with metalaxyl-human serum albumin(HSA) conjugate. Metalaxyl-protein conjugate was prepared by mixed anhydride and peptide coupling method with EDC. In this assay, metalaxyl-ovalbumin(OA) was $coated(8{\mu}g/ml)$ on the microtiter plate, which was incubated for 1 hr at $4^{\circ}C$ or 4 hr at $37^{\circ}C$ with diluted antiserum(1:2,000). The optimum volume ratio of antigen and antibody mixture was 0.5: 1, which was incubated for 1 hr at $20^{\circ}C$. The detection of metalaxyl bound on the surface of wells was determined by the reaction(30 min) of antirabbit Ig G-peroxidase conjugate with its substrate.

• Publications of The Korean Astronomical Society
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• v.15 no.spc2
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• pp.1-13
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• 2000

Through the coupling between the near-earth space environment and the polar ionosphere via geomagnetic field lines, the variations occurred in the magnetosphere are transferred to the polar region. According to recent studies, however, the polar ionosphere reacts not only passively to such variations, but also plays active roles in modifying the near-earth space environment. So the study of the polar ionosphere in terms of geomagnetic disturbance becomes one of the major elements in space weather research. Although it is an indirect method, ground magnetic disturbance data can be used in estimating the ionospheric current distribution. By employing a realistic ionospheric conductivity model, it is further possible to obtain the distributions of electric potential, field-aligned current, Joule heating rate and energy injection rate associated with precipitating auroral particles and their energy spectra in a global scale with a high time resolution. Considering that the ground magnetic disturbances are recorded simultaneously over the entire polar region wherever magnetic station is located, we are able to separate temporal disturbances from spatial ones. On the other hand, satellite measurements are indispensible in the space weather research, since they provide us with in situ measurements. Unfortunately it is not easy to separate temporal variations from spatial ones specifically measured by a single satellite. To demonstrate the usefulness of ground magnetic disturbance data in space weather research, various ionospheric quantities are calculated through the KRM method, one of the magneto gram inversion methods. In particular, we attempt to show how these quantities depend on the ionospheric conductivity model employed.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.248-252
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• 2003

This paper has a control method proposed for the effective self-tuning fuzzy speed control based on neural network of the induction motor indirect vector control. The vector control of an induction motor provides the decoupled control of the rotor flux magnitude and the torque producing current to performance is desirable. But, the drive performance often degrades for the machine parameter variations and its condition give rise to coupling of flux and torque current. The fuzzy speed control of an induction motor has the robustness about machine parameter variations compared with conventional PID speed control in a way. That proved to be some waf from the true. The purpose of this paper is to improve the adaptation by offering self-turning function to fuzzy speed controller. In this paper, the adaptive mechanism of fuzzy speed control in used ANN(Artificial Neural Network) technique is applied in an IFO induction machine drive, such that the machine can follow a reference model (an ideal field oriented machine) to achieve desired speed. In this paper proved the self-turning method of fuzzy controller has the robustness about parameter variation and the wide range of adaptation by simulation.

• BMB Reports
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• v.30 no.6
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• pp.403-409
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• 1997

Studies were undertaken to develop a competitive radioimmunoassay (RIA) and indirect antigen capture enzyme-linked immunosorbent assay (ELISA) for the determination of 5'-deoxy-5'-methylthioadenosine (MTA), which is formed from decarboxylated S-adenosylmethionine by spermidine and spermine synthase. Specific antiserum against MTA was raised in rabbits by immunization with MTA-BSA which was prepared by coupling BSA to oxidized MTA with periodate. Since MTA is oxidized easily to the sulfoxide, the sulfhydryl reagent, DTT. was added to the immunogen. For RIA, immunocomplexes were separated from free MTA by using ammonium sulfate precipitation. The antiserum showed almost no cross-reactivity with a variety of other nucleotides and riboses. But, the level of cross-reactivity of 5'-isobutylthioadenosine (SIBA) was high. These results showed the importance of hydrophobicity adjacent to the 5'-OH for determining antigenicity. The lower limit of detection by this assay was 100 fmol of MTA per tube. Using this assay. MTA levels were more easily and precisely determined in biological samples when compared with HPLC analysis. The RIA procedure is less time consuming. More than 24 analyses can be carried out in 2 h and required only a very small amount of sample ($20{\mu}l$ serum). In ELISA, biotin conjugated MTA-BSA was used as the labelled MTA. The sensitivity limit of this assay was lower than 100 pmol.