• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.61-63
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• 2004

The procurement of a mobile microwave scatterometer platform involved the consideration to ensure a mobile platform and equipment selected full-filled technical requirement and safety standard in Malaysia. Designing, and modification works involved engineering methodology in determining and selecting a suitable hydraulic telescopic boom that suit a selected mobile platform available locally. The mobile platform is a delivery system for microwave remote sensing microwave scatterometer and other accessories to any locations in Malaysia. Total loading to be carried by the mobile platform is 4500 kg and its overall weight must be 16,000 kg as recommended by hydraulic telescopic boom manufacturers. The telescopic boom will elevate microwave scatterometer system including the antenna to a maximum height of 27 m, and can also be rotated through $3600^{\circ}$. A mechanism is incorporated in the system to enable tracking or monitoring angular movement of the hydraulic telescopic boom when positioned towards predetermined target.

• Journal of electromagnetic engineering and science
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• 제12권1호
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• pp.107-114
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• 2012

Microwave imaging (MI) is one of the most promising and attractive new techniques for earlier breast cancer detection. Microwave tomography (MT) realizes configuration of a multistatic multiple-input multiple-output system and reconstructs dielectric properties of the breast by solving a nonlinear inversion scattering problem. In this paper, we describe ETRI 3D MT system with 3D MI reconstruction program and demonstrate its robustness through some examples of the image reconstruction.

• 전자공학회논문지A
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• 제32A권7호
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• pp.36-42
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• 1995

In this paper, the CAD program for designing the microwave waveguide narrow-band bandpass filters has been developed by the passband correction method with filter synthesis for the MDR(Microwave Digital Relay) system. Here, the modified double E-plane structures are employed in the filter structure which is analyzed by the variational method. Using the developed CAD program, 0.01dB equi-ripple chebyshev type 6-section bandpass filters used in the MDR system operating nationally is designed at the center frequency of 11.0GHz, fabricated with tunable type and then measured by tuning process. The experimantal results show good agreements with the theoretical results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.129-130
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• 2006

As the research of wireless personal area network (WPAN) is more activated, various communication systems operating on 2.4Ghz are being developed. Systems such as Bluetooth, 802.11b, Zigbee and DBO-CSS are operating on 2.4Ghz. In addition to these communication systems, microwave oven resides in 2.4Ghz, so co-existance between each of these communication systems and microwave Oven is considered important factor of system performance. The effect of microwave oven on these communication systems is so critical that these systems are recommended to avoid the impact of microwave oven by allocation of different channel. In this paper, based on the DBO-CSS operating on 2.4Ghz, we propose a new algorithm of reducing the effect of microwave oven to develop robust communication system against microwave oven.

• Journal of Nutrition and Health
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• 제34권3호
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• pp.299-305
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• 2001

The purpose of this study was to investigate the effects of catechin on the changes of microsomal mixed function oxidase(MFO) system and oxidative damage in rat liver exposed to microwave. Sprague-Dawley male rats weighing 200$\pm$10g body weight were randomly assigned to one normal and microwave exposed groups: microwave exposed groups were divided three groups: catechin free diet(MW) group, 0.25% catechin(MW+0.25C) group and 0.5% catechin(MW+0.5C) group to the levels of dietary catechin supplementation. The rats were irradiated with microwave at frequency 2.45GHz for 15 min and then the changes pattern of mixed function oxidase system and oxidative damage were investigated for 16 days. The activity of XOD in MW group was increased from 4 day to 8 days after irradiation, compared to normal group and decreased to the level of normal group 16 days. But catechin supplementation group were maintained to the normal level. The contents of cytochrome P(sub)450 and NADPH cytochrome P(sub)450 reductase activities in liver of MW group was increased from 4 day to 8 day after irradiation, compared to normal group and decreased to the level of normal group at 16 day. But catechin supplementation group were recovered to the normal level. The contents of superoxide radical in liver of MW group was increased 1.28, 1.25, 1.17 fold of normal group at 4,6 and 8 days days after irradiation. respectively, but catechin supplementation group were maintained the normal level. The contents of lipifuscin in liver have a same tendency in superoxide radical contents. These result suggested that the supplementation of catechin have control the mixed function oxidase system and oxidative damage and that may help to recover tissues from microwave damage. (Korean J Nutrition 34(3) : 299~305, 2001)

• 대한의용생체공학회:의공학회지
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• 제28권4호
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• pp.471-476
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• 2007

Various active microwave imaging techniques have been developed for cancer detection for past several decades. Both the microwave tomography and the UWB radar techniques, constituting functional microwave imaging systems, use the electrical property contrast between normal tissues and malignancies to detect the latter in an early development stage. Even though promising simulation results have been reported, the understanding of the functional microwave imaging diagnostics has been relied heavily on the complicated numerical results. We present a computationally efficient and physically instructive analytical electromagnetic wave channel models developed for functional microwave imaging system in order to detect especially the breast tumors as early as possible. The channel model covers the propagation factors that have been examined in the previous 2-D models, such as the radial spreading, path loss, partial reflection and transmission of the backscattered electromagnetic waves from the tumor cell. The effects of the system noise and the noise from the inhomogeneity of the tissue to the reconstruction algorithm are modeled as well. The characteristics of the reconstructed images of the tumor using the proposed model are compared with those from the confocal microwave imaging.

• ETRI Journal
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• 제40권2호
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• pp.188-196
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• 2018

This paper presents a pulse radar system to detect drones based on a target fluctuation model, specifically the Swerling target model. Because drones are small atypical objects and are mainly composed of non-conducting materials, their radar cross-section value is low and fluctuating. Therefore, determining the target fluctuation model and applying a proper integration method are important. The proposed system is herein experimentally verified and the results are discussed. A prototype design of the pulse radar system is based on radar equations. It adopts three different pulse modes and a coherent pulse integration to ensure a high signal-to-noise ratio. Outdoor measurements are performed with a prototype radar system to detect Doppler frequencies from both the drone frame and blades. The results indicate that the drone frame and blades are detected within an instrumental maximum range. Additionally, the results show that the drone's frame and blades are close to the Swerling 3 and 4 target models, respectively. By the analysis of the Swerling target models, proper integration methods for detecting drones are verified and can thus contribute to increasing in detectability.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.173-178
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• 2000

A prototype for a highly sensitive, automated measurement system for the microwave surface resistance of high-T$_c$ superconductor films was set up, and tested by measuring the microwave surface resistances of high-T$_c$ YBa$_2$Cu$_3$O$_{7-{\delta}}$(YBCO) films at the frequency of about 19.6 GHz and the temperature of 30 K ${\sim}$ 90 K. An open-ended TE$_{011}$ mode sapphire-loaded cylindrical cavity resonator was used as the measurement probe, where YBCO films were used as the endplates of the cylindrical cavity. The characteristics of the measurement system include functions to display the unloaded ${\varrho}$ and the resonant frequency of the TE$_{011}$ mode resonator as well as the microwave surface resistance of the YBCO films, all simultaneously as a function of temperature. Applicability of the measurement system for investigating the homogeneity in the microwave properties of large high-T$_c$ superconductor films is discussed.

• Progress in Superconductivity
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• 제2권1호
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• pp.27-32
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• 2000

A prototype for a highly sensitive, automated measurement system for the microwave surface resistance of high-$T_c$ superconductor films was set up, and tested by measuring the microwave surface resistances of high-$T_c$ $YBa_2Cu_3O_{7-\delta}$ (YBCO) films at the frequency of about 19.6 GHz and the temperature of 30 K $\sim$ 90 K. An open-ended $TE_{011}$ mode sapphire-loaded cylindrical cavity resonator was used as the measurement probe, where YBCO films were used as the endplates of the cylindrical cavity. The characteristics of the measurement system include functions to display the unloaded Q and the resonant frequency of the $TE_{011}$ mode resonator as well as the microwave surface resistance of the YBCO films, all simultaneously as a function of temperature. Applicability of the measurement system for investigating the homogeneity in the microwave properties of large high-$T_c$ superconductor films is discussed.

• Journal of electromagnetic engineering and science
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• 제15권4호
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• pp.250-257
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• 2015

This paper presents an experimental measurement system for 3-6 GHz microwave tomography (MT) of the breast. The measurement system is constructed as a minimal test bed to verify key components such as the sensing antennas, radio frequency (RF) transceiver, sensing mechanism, and image reconstruction method for our advanced MT system detecting breast cancer at an early stage. The test bed has eight RF channels operating at 3 to 6 GHz for high spatial resolution and a two-axis scanning mechanism for three-dimensional measurement. The measurement results from the test bed are shown and discussed.