• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2621-2625
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• 2007

This study aims at analyzing the flow characteristics of the electromagnetic pump using a linear induction motor (LIM) for transferring molten metals. The flow characteristics of the pump are simulated by magnetohydrodynamic(MHD) program. In this system, the LIM is used for transferring molten metal by electromagnetic force. The molten metal is treated as the secondary part of the LIM. Since the LIM produces an electromagnetic force in the duct, the molten metal can flow from the furnace to the reservoir. The flow characteristics of the pump are analyzed using MHD program for magnetic field of 0.1[T] in duct. In order to prove the analysis, we made a prototype electromagnetic pump using LIM.

• 전기학회논문지
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• 제56권9호
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• pp.1638-1642
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• 2007

This paper investigated the destruction effect of the semiconductors by impact of high power electromagnetic wave. The experiments is employed as an open-ended waveguide to study the destruction effects on semiconductor using a 2.45 GHz 600 W Magnetron as a high power electromagnetic wave. The semiconductors are located at a distance of $31cm\sim40cm$ from the open-ended waveguide and are composed of a LED drive circuit for visual discernment. Also the chip condition of semiconductor is observed by SEM(Scanning Electron Microscope) analysis. The semiconductor are damaged by high power electromagnetic wave at about 860 V/m. The SEM analysis of the destructed devices showed onchipwire and bondwire destructions. Based on the result, semiconductor devices should have plan to protect the semiconductor devices form high power electromagnetic wave. And the database from this experiment provides the basis for future investigation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.788-789
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• 2011

A comprehensive thermo-electromagnetic model has been developed to estimate temperature and electromagnetic distribution in an three-phase induction motor under steady state operation. Electromagnetic modeling enables us to predict thermal dissipation rates by eddy-current loss and copper loss in induction motors. Non-uniform temperature distributions are investigated to account for the strong effect of local temperature build-up on the motor performance and expected life-span. For more accurate thermal modeling purpose, Heat loss mapping method, which is matched up with electromagnetic losses and volumetric heat source, is developed and performed analysis. Heat loss mapping method can be greatly used as a design or diagnostic tool for three-phase induction motors with complex structural electromagnetic fields.

• 전기학회논문지P
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• 제65권1호
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• pp.13-17
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• 2016

EMC (Electro Magnetic Compatibility) of the electrical railway must be ensured for safety of passenger. Maglev trains has not friction between the wheels and the rails because levitation by an permanent magnets, electromagnets and superconducting magnets etc. So, it is advantageous to maintain a high speed without noise and vibrations. In this paper, we investigated that the magnetic field of the before and after installation electromagnetic waves absorber in order to analyze the effects of electromagnetic waves. The theoretical analysis of the electromagnetic wave absorber was simulated using finite element method. The magnetic field properties of electromagnetic waves absorber were measured by EMI (Electro Magnetic Interference) test receiver.

• 조명전기설비학회논문지
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• 제19권5호
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• pp.68-73
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• 2005

본 논문은 선형유도전동기를 이용한 전자기펌프의 특성해석에 대하여 연구한 것이다. 전자기 펌프는 선형유도전 동기의 추진력에 의하여 용융 금속을 이송할 수 있다. 추진력을 높이기 위해 유전 알고리즘을 사용하여 최대 추력을 가지는 선형유도전동기를 설계 하고, 선형유도전동기를 이용한 전자기 펌프의 특성해석을 유동해석에 의하여 분석하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제15권3호
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• pp.13-19
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• 2013

Superconducting field coils using a high-temperature superconducting (HTS) wires with high current density generate high magnetic field of 2 to 5 [T] and electromagnetic force (Lorentz force) acting on the superconducting field coils also become a very strong from the point of view of a mechanical characteristics. Because mechanical stress caused by these powerful electromagnetic force is one of the factors which worsens the critical current performance and structural characteristics of HTS wire, the mechanical stress analysis should be performed when designing the superconducting field coils. In this paper, as part of structural design of superconducting field coils for 17 MW class superconducting ship propulsion motor, mechanical stress acting on the superconducting field coils was analyzed and structural safety was also determined by the coupling analysis system that is consists of commercial electromagnetic field analysis program and structural analysis program.

• Journal of Communications and Networks
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• 제11권6호
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• pp.556-563
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• 2009

A side channel analysis is a very efficient attack against small devices such as smart cards and wireless sensor nodes. In this paper, we propose an efficient key detection method using a peak selection algorithm in order to find the advanced encryption standard secret key from electromagnetic signals. The proposed method is applied to a correlation electromagnetic analysis (CEMA) attack against a wireless sensor node. Our approach results in increase in the correlation coefficient in comparison with the general CEMA. The experimental results show that the proposed method can efficiently and reliably uncover the entire 128-bit key with a small number of traces, whereas some extant methods can reveal only partial subkeys by using a large number of traces in the same conditions.

• 한국전자파학회논문지
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• 제18권10호
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• pp.1117-1125
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• 2007

본 논문은 스마트카드에서 방사되는 전자파를 이용한 암호 분석용 소형 루프 프로브 설계와 프로브에 유기된 전자파 신호의 분석에 관한 연구이다. 암호 분석용 프로브는 일반적인 전자장 측정용 프로브와는 다르다. 그 이유는 제시된 프로브의 목적은 암호 장비의 비밀 키 해독에 필요한 정보를 얻기 위함이기 때문이다. 스마트카드에서 발생된 파형을 분석하여서 전자파 공격을 시도하기 때문에 프로브에 유기된 전압의 파형과 IC 칩에서 발생된 파형은 가능한 한 서로 동일해야 한다. 그 목적을 위해서 전자파를 이용한 암호 분석, 신호원의 근사 모델링, 암호 분석용 프로브의 특징, 전자파 신호 측정 그리고 프로브의 교정에 대한 검토가 필요하다. 스마트카드 칩의 소비 전력 신호와 제안된 프로브를 이용한 전자파 신호를 측정하고 두 신호를 EMA의 관점에서 비교하였다. ARIA 알고리즘을 적용하여 제안된 비접촉 암호 분석용 프로브의 적합성 여부를 실험적으로 확인하였다.

• 항공우주기술
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• 제7권1호
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• pp.161-169
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• 2008

본 논문에서는 KSLV-I 상단조립체에 대하여 수행된 시스템 인증수준의 전자파시험에서 GPS 수신기 시스템을 위한 시험 구성 및 운용 방법을 소개하고 성능분석 결과를 기술한 다. GPS 수신기 시스템은 이미 단품 수준에서 수차례의 설계 변경을 통하여 MIL-STD-461E 기준으로 규정된 KSLV-I 상단 전자장비 시험 규격을 만족함을 확인하였다. 시스템 인증수준으로 수행된 전자파시험에서 GPS 수신기 시스템은 다른 탑재물들과의 전자파적 간섭에도 정상적으로 동작하였으며 전계필드 입사 및 정전기 방전의 조건에서도 성능저하가 발생하지 않아 KSLV-I 상단 전자파환경 조건에서의 동작성이 검증되었다.

• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1429-1435
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• 2021

The temperature distribution of an electromagnetic pump was analyzed with a flow rate of 1380 L/min and a pressure of 4 bar designed for the sodium thermo-hydraulic test in the Sodium Test Loop for Safety Simulation and Assessment-Phase 1 (STELLA-1). The electromagnetic pump was used for the circulation of the liquid sodium coolant in the Intermediate Heat Transport System (IHTS) of the Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR) with an electric power of 150 MWe. The temperature distribution of the components of the electromagnetic pump was numerically analyzed to prevent functional degradation in the high temperature environment during pump operation. The heat transfer was numerically calculated using ANSYS Fluent for prediction of the temperature distribution in the excited coils, the electromagnet core, and the liquid sodium flow channel of the electromagnetic pump. The temperature distribution of operating electromagnetic pump was compared with cooling of natural and forced air circulation. The temperature in the coil, the core and the flow gap in the two conditions, natural circulation and forced circulation, were compared. The electromagnetic pump with cooling of forced circulation had better efficiency than natural circulation even considering consumption of the input power for the air blower. Accordingly, this study judged that forced cooling is good for both maintenance and efficiency of the electromagnetic pump.