• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.695-699
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• 2005

Propriety of PERT network for planning and management in large-scale systems was investigated. We also review the example of small and middle size system to compare the appropriateness of PERT analysis method. For comparing the appropriateness of PERT analysis method the calculation time, and the variances were estimated. Eventualy, we proposed the criteria of PERT analysis method for planning and management large-scale systems.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.100-106
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• 2005

This paper addressed the issue of the three-phase load flow program for electric power distribution systems that include distributed generations. The equipment models were selected in order to consider imbalances among phases for the load flow analysis of distribution systems. Also, power equations and measurement functions are newly derived. The load flow analysis program developed in this paper was tested for the propriety of algorithm and convergence characteristics by case studies on test systems in various scales and types.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.6
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• pp.273-281
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• 2001

In order to overcome the demerit and to improve the operation characteristics of Moving Coil type Linear Oscillatory Actuator(MC-LOA) with single-pole permanent magnet, this paper presents two models having the balanced magnetic circuit by multi-pole permanent magnet. They are short coil type with two-pole single-sided and two-ple double-sided permanent magnet. The characteristics between single-pole and multi-pole permanent magnet type MC-LOA are compared. As a result, multi-pole type MC-LOA has more merits than single-pole type about operation characteristics improvement and machine volume. The characteristics analysis is performed by their dynamic analysis composed of kinetic and electric equations and Finite Element Method(FEM). The propriety of multi-pole type MC-LOA model is verified with analysis results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.91-98
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• 1998

The current-fed high frequency inverter with separated parallel resonant capacitor is presented in this paper. The analysis of the proposed circuit is generally described by using normalized parameter, and are evaluated characteristics of the circuit.In addition, this paper proves the propriety of theoretical analysis in terms of the experimental waveforms using the switching device MOSFET. In the future, the proposed inverter will expected that it can be practically used as the high frequency power source for induction heating etc.ng etc.

• Journal of the Korea Safety Management & Science
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• v.9 no.2
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• pp.71-83
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• 2007

This study created a computerized information system of the collected job analysis data and analyzed the computerized job analysis data to derive critical job factors. Based on the ratings on each critical job factor, possible employment opportunities for the various types of disability could be derived according to the match between job condition and handicap condition. The results can be utilized by the Employment and Vocational Training Administration to expand both the counselor and counselee's perspectives about job possibilities and job requirements.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.5
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• pp.453-461
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• 1990

In this paper, a short primary-short secondary single-sided linear induction motor which is used as the driving source for an automatic conveyor system, is selected as an analysis model. The finite element method in which the current vector potential is introduced is adopted to analyze the eddy current distribution and thrust force which are produced according to the relative position of the primary and the secondary. Also, the analysis results are compared with experimental ones, to show the propriety of this model.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.1
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• pp.29-35
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• 1990

This paper proposes a tow-dimensional magnetic flux distribution analysis of the double-sided linear induction motor(DLIM). Both the longitudinal end-effect and the transverse edge-effect, which are due to the finite length and width of the primary stator, are considered. Also each force which is due to the variation of slip frequency was computed to show the fact that the thrust force of DLIM is dependent on both the longitudinal end-effect and the transverse edge-effect. To ascertain the propriety of this analysis, the simulated results of the magnetic flux density distribution in the airgap are compared to the experimental data.

• Proceedings of the KIEE Conference
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• summer
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• pp.962-964
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• 2004

The plunger speed of solenoid actuator is affected by mass of plunger, magnetic motive force, inductance, and return spring. These factors are not independent but related with each other according to design characteristics of solenoid actuator. So, it is impossible to change the designed value for the purpose of increasing plunger speed. In this study, we have analyzed the characteristics of high-speed solenoid actuator having a non-magnetic ring which plays a role to concentrate the effective magnetic flux into plunger. For more detailed analysis, we have induced characteristic equations and performed FEM analysis and simulation for dynamic characteristics of plunger, and proved the propriety of these by experiments.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1086-1088
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• 2005

It is necessary to modify the state-of-the-art of vector control theory, because of the phase asymmetry(static end effect) in the Linear Induction Motor(LIM). The dynamic characteristic analysis method of the vector controlled LIM using coupled FEM and control algorithm taking into account the movement is proposed. The focus of this paper is the analysis relative to phenomena of static end effect due to the motor structure. To prove the propriety of the proposed method, the Digital Signal Processor(DSP) installed experimental devices are equipped and the experiment is performed.

• Korean Journal of Construction Engineering and Management
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• v.10 no.3
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• pp.32-41
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• 2009

In the execution of construction management, such pre-design steps as a planning stage, a basic design stage, and a work design stage are regarded as more important than an actual construction stage. However, the manpower input criterion from the aspect of construction management price standard in the Construction Engineering Management Law does not attach weight to the pre-design stage. In this regard, the aim of this study was to examine the propriety of manpower input in the pre-design stage of construction management and then present an improvement strategy of it. For this, the investigator examined the criterion of service price prescribed in the Construction Engineering Management Law and then comparatively analyzed four sites of construction management services. Study findings are as follows: 1) the actual state of manpower input based on the stepwise average price criterion of construction management service is presented with such steps as the newly established planning step (6.6%), the basic design stage (3.9%$\rightarrow$5.6%), the practical design stage(7.6%$\rightarrow$13.5%), the construction stage (88.5%$\rightarrow$64.0%), and the newly established maintenance stage (10.3%). The average price criterion is classified by total construction expenses and calculated by improved rates and stage; and 2) the three-step criterion of the Construction Engineering Management Law is classified into five stages including the planning stage and the maintenance stage by dividing it with the stepwise construction businesses. Study findings show that the calculation of price criterion in the actual site of construction management services must be operated in a practical and flexible manner and the systematic improvement of stepwise manpower input must be carried out actually.