• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.4
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• pp.199-206
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• 2022

제주공항은 슬롯 증대사업을 통한 정시성 개선 노력에도 불구하고 항공 교통량의 확대에 따른 혼잡도의 증가가 지속되고 있다. 제주공항 혼잡도의 근본적인 해소를 위해서 추진되고 있는 신공항 건설이 여러 가지 사유로 지연되고 있으며, 실제 건설계획이 확정되더라도 정상적인 공항 운영까지 상당 기간의 시간이 소요될 것으로 예상된다. 따라서 제주 신공항 건설이라는 대규모 신규 투자와는 별개로 신공항 개항 전, 기존 제주공항을 운영하면서 혼잡도를 해소할 수 있는 중단기적 대안을 마련할 필요가 있다. 이에 국토교통부와 한국공항공사는 제주공항에 소형기보다는 최대이륙중량 100톤 이상의 대형항공기(통상 270석 이상 공급) 투입을 유도하는 착륙료 감면 조치를 시행하였으며, 최초 착륙료 10% 감면에서 추가 활성화를 위하여 착륙료 20% 감면으로 확대하여 운영 중이다. 항공사는 착륙료 감면 비율 상향을 통해 대형기 투입에 따른 실질적인 비용이 절감된다면 상기 정책에 적극 동참하게 될 것이다. 본 논문에서는 제주공항에서 실시 중인 착륙료 감면율 확대 조정이 항공사의 대형기 배정에 미치는 효과를 분석하여 정책의 실효성을 고찰하였으며 이에 따른 개선책을 제시하였다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.3 no.1
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• pp.81-95
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• 1995

공기의 흐름 중에 있는 유한 날개의 끝에서는 날개끝 와류로 인하여 날개에 내리흐름(downwash)이 발생하게 된다. 이러한 내리흐름은 유도항력을 발생시켜 양항특성이 감소하게 된다. 따라서 날개끝 와류를 적절히 제어하면 어느 정도 유도항력을 감소시킬 수 있다. 본 논문에서는 직사각형 날개와 테이퍼형 날개 끝에 여러 가지 형상의 strake를 장착하거나, 날개끝 와류를 제어하기 위하여 여러 개의 slot을 형성시켰을 때의 양항특성을 실험 및 수치해석으로 연구한 결과를 기술하였다. 실험결과 직사각형 날개끝에 장착한 wing tip strake의 밑변을 바깥쪽으로 절단한 wing tip strake의 양항특성이 받음각 $8^{\circ}$ 이상에서 우수하였고, 반면에 밑변을 절단하지 않은 경우는 받음각 $0^{\circ}\;^{\sim}\;8^{\circ}$ 사이에서 기본날개보다 양항비가 증가하였다. 테이퍼형 날개끝에 wing tip strake를 장착하였을 때의 양항비는 받음각 전 범위에 걸쳐 기본날개보다 증가하였으며, 받음각$8^{\circ}$ 이상에서 wing tip strake의 밑변을 절단하지 않은 wing tip strake의 양항특성이 우수하였다. 방사형 다중슬롯의 경우 날개끝의 앞전보다 뒷전 쪽에 형성시키는 것이 양항비특성이 우수하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.697-705
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• 2009

This paper presents the theoretical tag-reading speed in the ASK and the PJM mode of a 13.56MHz RFID system which have been adopted in the international standard ISO 18000-3, along with simulation results to support the mathematical analysis. Through the analysis using the number of tag-dependent Q-algorithm, which was known to give relatively fast reading speed, we not only derive the number of slots to read out given tags, but compare the reading speeds of the ASK with that of the PJM mode. Moreover, we present the numerical comparison of two modes which bring the equivalent results as in the theoretical one.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.203-205
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• 2006

This paper presents a study on the winding method and structure of core of single phase induction motor in order to design the high efficiency motor. In case of single phase induction motor, winding fill factor and the number of turns in each slot are not uniform in general. Moreover, these can be the critical parameters for high efficiency design in case the size of motor should be restricted within certain volume. Therefore, we should analyze the effects of these parameters related to efficiency parameter. The characteristic analysis was performed by using FEM.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.241-243
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• 1996

This papar presents an analysing method of radial force densities acting on each stator tooth of an induction motor with skewed slots. Two-dimensional finite element method is used for electromagnetic Held analysis of an induction motor, and skew effects are considered by coupling several disks cut by planes perpendicular to the shaft. Radial force densities as a source of vibration are calculated along the surface elements of each stator tooth and its time harmonics are examined by discrete Fourier decomposition.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2077-2078
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• 2011

Now a days, the induction motor is widely used in industry automation. Without monitoring the motor fault, maintenance cost is increased undesirably high. The slip frequency is included in the feature frequency, so rotating rotor speed is needed. In this paper, a sensorless motor speed estimation method, rotor slot harmonic(RSH) method is suggested and a solution of rotor bar diagnosis is proposed for motor running with light-load. When the rotor is rotating, it shows the harmonic signal of back-emf voltage related with number of rotor slot. So from the power spectrum of current signal, we can find the rotor speed.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.21-23
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• 2007

It is well known that the characteristics of the induction machine depend on a great degree on the leakage reactance. And the leakage reactance is different according to a level of slant. So in this paper, we calculated the inductance per coil side. And the torque and speed characteristics are analyzed using a method base on the two-dimensional (2-D) finite element method (FEM) and on the circuits theory to model the rotor bar in a induction machine. The variable values of bar angle of slant are considered.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.7
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• pp.331-338
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• 2002

An inverter-fed induction is driven by a harmonic voltage source so that it is necessary to be analysed by time-stepping F.E.M. But it takes so long time that disadvantageous to design. This paper presents a simple analysis method for inverter-fed induction motor using FEM and harmonic equivalent circuit. First, the rotor bar resistance and the leakage reactance are determinated by FEA for 1 slot region in rotor to consider the skin effect and the saturation. Secondly, the characteristic of the motor is analyzed by the harmonic equivalent circuits consisting of the obtained parameters from the FEA. This method is carried out to analyze an induction motor driven by the sinusoidal voltage and the inverter. The results are verified by comparing with those of the time-step F.E.A and the experiment.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.86-88
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• 2004

In this paper, optimal stator slot shape of 3-phase inverter-fed induction motor is designed to reduce stator core and winding losses. For the analysis, the F.E.M on 1 phase band periodic condition in stator is coupled with harmonic equivalent circuit. For the optimal design, the conjugate gradient method is used as an optimizing algorithm. The stator core and winding losses are reduced by the design method. The results are verified by those of the time-step finite element analysis.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.52-54
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• 1997

This paper deals with investigating some characteristics of the inverter-driven tractive induction motor according to the various rotor slot number. 2-D time-stepped finite element method considering the inverter voltage waveform is utilized for electromagnetic field analysis. As a result, harmonics spectra of torque and bar loss are compared in each case.