• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.2
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• pp.116-121
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• 2009

Distributed power systems (DPSs) has been widely used various industrial/military applications due to their various advantages. Furthermore, the "All electric" concept, in conjunction with DC DPS, appears to be more advanced and mature in the AEV(All-Electric Vehicular) industry. Generally, AEV carry many loads with varied functions. However, there may be large pulsed loads with short duty ratios which can affect the normal operation of other loads. In this paper, a converter with spilt capacitors and a simple adaptive controller is proposed as a active damping device to mitigate the voltage transients on the bus. The proposed converter allows the smaller capacitive storage. In addition, the proposed control approach has the advantage of requiring only one sensor and performing both the functions of mitigating the voltage bus transients and maintaining the level of energy stored. The control algorithm has been implemented on a TMS320F2812 Digital Signal Processor (DSP). Simulation and experimental results are presented which verify the proposed control principle and demonstrate the practicality of the circuit topology.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.472-475
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• 2008

A DC distributed power system(DPS) has many loads with varied functions. In particular, there may be large pulsed toads with short duty ratio, which can affect the normal operation of other loads. In this paper, a bi-directional converts with inductive storage is used as a DC bus conditioner to damp voltage transients on the bus. In addition, the constant frequency hysteresis control technique for a DC bus conditioner is presented. A simple and fast prediction of the hysteresis band-width is implemented by the phase-lock loop control, keeping constant switching frequency. This technique offers the excellent dynamic response in load or parameter variation. The control performance is illustrated by simulated results with the SABER package. The proposed hysteresis control results in the shortest and the smallest excursions.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.2
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• pp.127-137
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• 2002

Phenolic compounds in air are toxic even at their low concentrations. We had evaluated a total of five phenolic compounds (Phenol, o-Cresol, m-Cresol, 2-Nitrophenol and 4-Chloro-3-methylphenol) in artificial air using a combination of ATD/GC/MS. To compare the adsorption efficiency of these phenolic compounds, three adsorbents (Tenax TA, Carbotrap and Carbopack B) were tested. Tenax TA adsorbent was most effective of all the adsorbents used for the efficiency test. Five phenolic compounds were found to be very stable on adsorbent tubes for 4 days at room temperature. Detection limit of five phenolic compounds ranged from 0.05 to 0.08 ppb (when assumed to collect 10 L air). The calibration curve was linear over the range of 22∼ 164 ng. The reproducibility was less than 4%. Sampling of duplicate pairs (DPs) was made to demonstrate duplicate precision and sampling efficiency.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.839-841
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• 2004

This paper presents a SPMSM servo motor drive system using high performance TMS320 F281T DSP for the industrial application. This high performance DSP contains some special peripheral circuits such as PWM (Pulse Width Modulation) waveform generation circuit, Quadrature Encoder Pulse (QEP) generation circuit and Analog to Digital Converter (ADC) circuit. In this paper, a servo drive control system is constructed using high performance DPS for the overall system cost reduction and the size minimization.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.1
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• pp.8-19
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• 2003

Special purpose vessels such as drillship and ocean research vessels install the DPS(Dynamic Positioning System) to maintain the position and heading for long-time operation. This paper deals with the design parameters for the control theory and filter algorithms of DP system. for the environmental loadings wind forces, current forces and wave forces were considered. In order to estimate the low frequency motions without first-order wave motion, the Kalman filter was used and it was assumed that the first-order wave forces correspond to system noises and first-order wave motions are measurement noises. In this simulation, the length of research vessel is 65 meters and it has four thrusters to maintain the position. The ability of keeping position and heading was confirmed. For the calculation of thruster input the LQR and LOI control theory were adopted and the effects of gain were investigated.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.461-466
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• 1994

This paper is concerned with the positioning control of a flexible arm system using H$_{\infty}$ control theory with optimum sensor location. Firstly, by virtue of the orthogonality of the flexible modes of the flexible arm a reduced order model of the tributed parameter system(DPS) representing the arm has formulated. The dynamical coupling between the flexible arm and DC motor has been considered to formulate an motor composite model. In order to achieve precise positioning with vibration attenuation, sensors have been optimally located. Finally, a robust H$_{\infty}$ controller was designed and the performance of the positioning system has been analyzed.d.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.319-323
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• 1994

In this paper, we discuss a design method of iterative learning control systems for parabolic linear distributed parameter systems(DPSs). First, we discuss some aspects of boundary control of the DPS, and then propose to employ the Karhunen-Loeve procedure to reduce the infinite dimensional problem to a low-order finite dimensional problem. An iterative learning control(ILC) for non-square transfer function matrix is introduced finally for the reduced order system.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.2
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• pp.9-17
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• 1994

This paper proposes Double queue threshold QLT(Queue Length Threshold) algorithm and Hysteresis effect QLT algorithm. as being DPS(Dynamic Priority Scheduling) techniques. in order to advance the processing of multiple class traffics. Also, the performance of the proposed algorithms is analyzed through computer simulations,and the priority scheduling is analyzed using a retrial queue with two types of calls. Our simulation results show that the performance of the proposed Double queue length threshold QLT algorithm is superior to that of the conventinal QLT algorithm for 2 or more classes delay sensitive traffics. Also we find that Hysteresis effecT QLT algorithm is better mechanism than that of the existing QLT for real time and non-real time traffics.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.118-122
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• 2020

Inorganic-organic hybrid perovskite solar cells have demonstrated a significant achievement by reaching a certified power conversion efficiency of 25.2% in 2019 as compared to that of 3.8% in 2009. However, organic hole conductors such as PTAA and spiro-OMeTAD are known to be expensive and unstable when they are exposed to operational conditions. In this study, the inorganic hole conductor CuSCN was used to overcome such concerns. The influence of dipropyl sulfide (DPS) and diethyl sulfide (DES) as CuSCN deposition solvents on the underlying perovskite active layer was investigated. DES solvent was observed to be advantageous in terms of CuSCN solubility and mild for the perovskite layer, thereby resulting in a power conversion efficiency of 16.9%.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.532-541
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• 2007

This paper investigates children's comprehension and production of demonstrative pronouns (DPs), 'zhege' (this) and 'nage' (that), in Mandarin Chinese. Subjects are children of ages three, four, five and six. Based on the results of the present experiment, children's developmental stages and the corresponding age grading are provided. Also, the present study incorporates a physical clue into the experiment. The result suggests that in the acquisition of deixis children rely highly on physical context to work out the meaning distinction. In addition, Piaget's egocentrism hypothesis and H. Clark's marking hypothesis are examined in the study. The result seems to support the egocentrism hypothesis. Subjects under the age of six do fail to shift the deictic center when they and the experimenter have a different perspective. As for the marking hypothesis, the study seems to challenge the hypothesis. The result shows that children actually performed better on the marked term 'zhege' than the unmarked member 'nage'.