• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.1-11
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• 2007

In this paper, a new fully digital control method for UPS inverter, which is based on the double control loop such as the outer voltage control loop and inner current control loop, is proposed. In the proposed control system, overshoots and oscillations due to the computation time-delay are compensated by explicit incorporation of the time-delay in the current control loop transfer function. The inner current control loop is adopted by an internal model controller. The internal model controller is designed to a second order deadbeat reference-to-output response which means that its response reaches the reference in two sampling time including computational time-delays. The outer voltage control loop employing P-Resonance controller is proposed. The resonance controller has an infinite gain at resonant frequency, and the resonant frequency is set to the fundamental frequency of the reference voltage in this paper. Thus the outer voltage control loop causes no steady state error as regard to both magnitude and phase. The effectiveness of the proposed control system has been verified by the simulation and experimental results respectively.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.809-818
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• 2020

This study aims to analyze the factors affecting the timeliness of cooperative financial reporting. The methods of measurement and accountability of financial statements must be timely, as it is critical information for making decision. Factors related to accounting information system problems such as timeliness of financial reporting, accounting information systems, teamwork, and internal control were identified in the study as a model. The method in this research is quantitative by taking survey data. The data were processed using SPSS 25, with a model test and partial test to produce a study to analyze the factors that affect the timeliness of cooperative financial reporting. The samples consisted of 60 cooperatives from the city of Tangerang, in Indonesia. The correspondents have published financial reports for each period of the current year and were a legal entity. Furthermore, primary data were collected by a questionnaire using a Likert scale and analyzed by multiple linear regression. The results showed that the Accounting Information System, Teamwork, and Internal Control had a positive and significant effect on the Timeliness of Financial Report Submission. Therefore, the cooperative that prepares financial reports in a timely manner has applied the principles of accountability and transparency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1487-1493
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• 2013

A new simple control method for active power filter, which can realize the complete compensation of harmonics is proposed. In the proposed scheme, a model-based digital current control strategy is presented. The proposed control system is designed and implemented in a form referred to as internal model control structure. This method provides a convenient way for parameterizing the controller in term of the nominal system model, including time-delays. As a result, the resulting controller parameters are directly set based on the power circuit parameters, which make tuning of the controllers straightforward task. In the proposed control algorithm, overshoots and oscillations due to the computation time delay is prevented by explicit incorporating of the delay in the controller transfer function. In addition, a new compensating current reference generator employing resonance model implemented by a DSP(Digital Signal Processor) is introduced. Resonance model has an infinite gain at resonant frequency, and it exhibits a band-pass filter. Consequently, the difference between the instantaneous load current and the output of this model is the current reference signal for the harmonic compensation.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.5
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• pp.385-394
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• 2004

This paper proposes the generalized structure of a model-based disturbance rejection controller called a Robust Internal-loop Compensator (RIC). The framework consists of the RIC in the internal-loop to eliminate disturbances and a feedback controller in the external-loop to achieve nominal control performance. As the main contribution of this paper, we redefine the design problem of the RIC as a regulation control problem, then show that this new definition with the RIC structure provides more design flexibility and less implementation constraints. This is verified through a comparative structural analysis with Disturbance Observer (DOB) and Adaptive Robust Control (ARC). Two design examples of the RIC are given, along with practical issues that should be considered in the design procedure. The proposed framework is demonstrated by simulations of a rotary-type motor and experiments with a linear-type motor system.

• The Journal of Internal Korean Medicine
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• v.22 no.4
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• pp.601-611
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• 2001

Objectives : We aimed to identify the dose-dependent inhibitory effects of Cheonsagunja-tang(喘四君子湯), leech(Hirudo medicinalis/水蛭) roasted with Ephedrae Herba(麻黃) on the mRNA expression of IL-6, IL-16, GM-CSF involved in the asthma model. Methods : In the study BEAS-2B cell lines, human epithelial cells were used. These cells were stimulated with tumor necrosis factor(TNF)-${\alpha}$ for artificial inflammatory expression. ${\beta}$-actin messenger RNA(mRNA) was used by internal standard. After 24 hours of the Cheonsagunja-tang, leech-treatment, total cellular RNAs were collected treating RNA zol directly on the living cells. Then the transcriptional activities of IL-6, 16 and GM-CSF were measured by RT-PCR with electrophoresis. Results: In the Cheonsagunja-tang study, the mRNA expression of IL-6 showed 30% transcriptional inhibitory effect compared to the control group in the $100{\mu}l/ml$ category(p<0.005). In the IL-16, there was 26%, 31% and 31% transcriptional inhibitory effect compared to the control groups in the $4{\mu}l/ml$, $20{\mu}l/ml$ and $100{\mu}l/ml$ categories, respectively(p<0.05). In the GM-CSF, the experimental group had 56% transcriptional inhibitory effect compared to the control group in the $100{\mu}l/ml$ category(p<0.001). In other concentrations, there was no inhibitory effect. In the leech study, the mRNA expression of IL-6 showed 37% transcriptional inhibitory effect compared to the control group in the $100{\mu}l/ml$ category(p<0.001). In the IL-16, there was 63% and 67% transcriptional inhibitory effect compared to the control groups in the $20{\mu}/ml$ and $100{\mu}/ml$ categories, respectively(p<0.001). In the GM-CSF, there was 64% and 68% transcriptional inhibitory effect compared to the control groups in the $20{\mu}l/ml$ and $100{\mu}l/ml$ categories, respectively(p<0.001). In other concentrations, there was no inhibitory effect. Conclusions : This study shows that Cheonsagunja-tang and leech roasted with Ephedrae Herba have dose-dependent inhibitory effects on the mRNA expression of IL-6, IL-16 and GM-CSF in BEAS-2B cell lines, human epithelial cells.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.157-160
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• 2002

When the teleoperation system has a signal transmission time delay between slave system and control system, the position tracking performance of the slave system and system stability are likely to be deteriorated. This paper proposes a force reflecting position control scheme for teleoperation system with signal transmission time delay. The proposed scheme not only satisfy the system internal stability but also improves the position tracking performance with disturbance rejection capability. The simulation results show that the proposed control method provides excellent performances.

• Architectural research
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• v.7 no.2
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• pp.47-54
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• 2005

A photoelectric dimming control system for a small private office space with a double skin envelope system was analyzed for the purpose of examining optimum control performances under a variety of daylight conditions. Computer simulations were performed for the three different photosensor types positioned at the center of ceiling in the space. They were applied in both a south and north-facing room. Daylight conditions were a fixed horizontal venetian blind on an external envelope and a retractable shading device on an internal envelope under a clear, intermediate and overcast sky at different times of a day and year. Partially-shielded photosensors provided good control performances providing the required electric light output under clear and intermediate sky conditions. Unshielded photosensors failed to provide necessary illuminance levels producing less electric output and fully-shielded photosensors generally provided excessive light output. Reasonable electric lighting energy savings were achieved except under overcast sky conditions where the control system did not contribute to energy savings due to the less daylight through envelopes. The retractable shading device covering 50% of the internal envelope reduced energy savings up to 19.62%, but the workplane illuminance levels were maintained within recommended ranges. The coefficients of determination between workplane illuminance and photosensor illuminance due to daylight ranged from 0.74 to 0.98. Partially-shielded conditions provided best correlations and the north-facing room yielded stronger correlation than the south-facing room.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.108-110
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• 2006

This paper deals with a tracking problem for nonlinear systems using its T-S fuzzy model and internal model. We extend the internal model of linear systems to an internal model of T-S fuzzy systems to accompany with state error of zero. A sufficient condition of the existence of a tracking controller for T-S fuzzy systems is expressed by linear matrix inequalities. A system of inverted pendulum on cart is illustrated to verify our method.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.40-41
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• 2003

The present topic in pharmaceutical industry is to establish Quality Assurance System for medicinal product Therefore, the most important and urgent subject to be solved in the field of the manufacturing industry is to establish, implement and maintain the control system for ensuring uniformity of medicinal product. In case of solid dosage forms for internal use, its quality was controlled by disintegration test, etc but at present bioavailability could be predicted with dissolution test and so the assurance of its uniformity should be prerequistie to preserve suitable dissolution of the manufactured medicinal product. (omitted)

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.758-771
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• 2021

This paper presents a novel control scheme for the three-dimensional (3D) path following of underactuated Autonomous Underwater Vehicle (AUVs) subject to unknown internal and external disturbances, in term of the time scale decomposition method. As illustration, two-time scale motions are first artificially forced into the closed-loop control system, by appropriately selecting the control gain of the integrator. Using the singular perturbation theory, the integrator is considered as a fast dynamical control law that designed to shape the space configuration of fast variable. And then the stabilizing controller is designed in the reduced model independently, based on the time scale decomposition method, leading to a relatively simple control law. The stability of the resultant closed-loop system is demonstrated by constructing a composite Lyapunov function. Finally, simulation results are provided to prove the efficacy of the proposed controller for path following of underactuated AUVs under internal and external disturbances.