• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.1
• /
• pp.88-93
• /
• 2005

In this study, the operational characteristics on heating performance and energy consumption for intermittent hot water heating system in apartment buildings were research by simulation. The effects of apartment inlet hot water temperature and operation time per day on energy consumption and indoor thermal environment are investigated. The strategy of energy saving and thermal environment improvement is suggested in comparison with the existing ones.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.336-339
• /
• 2006

In this paper, the preliminary transfer orbit analysis results for the COMS mission were presented. As the first step of transfer orbit analysis, the preliminary analyses of LAE burn strategy, geometrical visibility, and launch window were performed. For the analysis process, all launcher nominates were divided into three groups according to the declination of LAE thrust angle. So, the three launch cases were assigned as the representative launcher of each group, respectively. They are Ariane-5, Atlas summer and winter launch cases. And all analyses were performed at the representative launcher of each group. One nominal and three back-up plans were considered for the establishment of LAE burn strategy. And for geometrical visibility analysis, four TT&C ground stations were considered. Finally, the preliminary launch window analysis was performed about the duration of one year from the first day of September 2008. The analysis results show that the all launch cases comply with the transfer orbit operation requirements.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.177-180
• /
• 1996

Fuzzy control systems depend on a number of parameters such as the shape or magnitude of the fuzzy membership functions, etc. Conventional fuzzy reasoning method can not be easily applied to the multi-input multi-output(MIMO) system due to the large number of rules in the rule base. Recently Z. Cao et al have proposed a New Fuzzy Reasoning Method(NFRM) which turned out to be superior to Zadeh's FRM. We have extended the NFRM to handle the MIMO system. However, it is difficult to choose a proper relation matrix of the NFRM. Therefore, we have modified the evolution strategy(ES), which is one of the optimization algorithms, to do efficiently the tuning operation for the extended NFRM. Finally we applied the extended NFRM with the modified ES to tracking control of robot manipulator.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1012-1015
• /
• 1996

This study focuses on the optimal operation and control strategy of the fuel cell process. The control objective of the Phosphoric Acid Fuel Cell (PAFC) is established and dynamic modeling equations of the entire fuel cell process are formulated as discrete-time type. On-line optimal control of the MIMO system employs the direct decomposition-coordination method. The objective function is modified as the tracking form to enhance the response capability to the load change. The weight factor matrices Q,R, which are design parameters, are readjusted. This control system is compared with LQI method and the results show that the suggested method is better than the traditional method in pressure difference control.

• International Journal of Control, Automation, and Systems
• /
• v.4 no.1
• /
• pp.113-123
• /
• 2006

In this paper, an improved direct torque control (DTC) method for sensorless matrix converter drives is proposed which enables to minimize torque ripple, to obtain unity input power factor, and to achieve good sensorless speed-control performance in the low speed operation, while maintaining constant switching frequency and fast torque dynamics. It is possible to combine the advantages of matrix converters with the advantages of the DTC strategy using space vector modulation and a flux deadbeat controller. To overcome the phase current distortion by the non-linearity of a matrix converter drive, the simple non-linearity compensation method using PQR power theory are presented in the proposed scheme. Experimental results are shown to illustrate the feasibility of the proposed strategy.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.1 no.2
• /
• pp.85-90
• /
• 2012

This paper presents a topology structure and control method for an input-parallel-output-series(IPOS) inverter system which is suitable for high input current, high output voltage, and high power applications. In order to ensure the normal operation of the IPOS inverter system, the control method should achieve input current sharing(ICS) and output voltage sharing(OVS) among constituent modules. Through the analysis in this paper, ICS is automatically achieved as long as OVS is controlled. The IPOS inverter system is controlled by a three-loop control system which is composed of an outer common-output voltage loop, inner current loops and voltage sharing loops. Simulation results show that this control strategy can achieve low total harmonic distortion(THD) in the system output voltage, fast dynamic response, and good output voltage sharing performance.

• Culinary science and hospitality research
• /
• v.12 no.3 s.30
• /
• pp.61-74
• /
• 2006

The objective of this study are to examine how the factors influence each other by determining the appropriate measurement standard based on the Dining-out Motives, restaurant attribute evaluation, intention of word of mouth and reusing, an effective restaurant marketing strategy on the basis of the analytical results by patrons and market segmentations. The study surveyed 321 subjects and processed the result using SPSS for Win. V. 12.1. For statistical analysis, Frequency, Factor Analysis, and Regression were put into operation. The results showed that dining-out motives and restaurant attribute evaluation had positive effects on the intention of word of mouth and reusing. Furthermore, the restaurant owners or managers will need to understand the existing market and target markets more objectively, and, through this market segmentation, formulate a marketing strategy that is appropriate for diverse desires of customers and different characteristics of restaurants.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.303-308
• /
• 1992

In this study, we propose a shared storage system which is more efficient policy than MIS(Mixed Intermediate Storage) policy for relatively rare storage system and can be called CIS(Common Intermediate Storage) policy. Using this strategy, we develop a new completion time algorithm and apply it to two kinds of optimal or near optimal scheduling method; combinatorial search and simulated annealing method. We also extend this strategy to other storage policy, for example MIS policy, with PLC(Programmable Logic Controller) logic and on/off action of electronic valves. It thus can be accepted as a basic form of FMS(Flexible Manufacturing System) for operating various storage policies. Finally we suggest the interlocking block to compansate for the shortcoming of CIS policy, i.e, complication of operation and safety, resulting in a basic batch process automation mode.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.979-984
• /
• 2005

2005, National railway was converted from government enterprise form to public corporation form. Korail is facing in necessity to equip new manpower operating system to achieve public enterprise's part and two purposes called profit creation according to conversion to construction system. Accordingly, railway construction work began services for formation diagnostic and job analysis to construct management formation of new paradigm, personnel management course manpower operation system of the job value priority. This dissertation is research for direction establishment of human resource management(HRM) of railway construction work. Examined problem of current personnel management system with trend of HRM paradigm for this. And presented various strategy to construct greeting executive system of job putting first in person putting first and strengthens formation capacity.

• International Journal of Precision Engineering and Manufacturing
• /
• v.1 no.2
• /
• pp.105-114
• /
• 2000

An output feedback control (OFC) is presented for a linear stochastic system with known disturbance and applied to a flexible spacecraft for the reduction of residual vibration while allowing the natural deflection during operation. By converting the tracking problem into regulator problem, the OFC minimizes the expected value of a guadratic objective function composing of error stats which always remain on the intersection of sliding hypersurfaces. For the numerical evaluation with a flexible spacecraft, a large slewing maneuver strategy is devised with a tracking model for nominal trajectory and start-cost-stop strategy for economical maneuver in conjunction with the input shaping technique. The performance and efficacy of the proposed control scheme are illustrated with the comparison of different maneuver strategies.