J.-H. Lee

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Lattice thermal conductivity ␬ l of Si with nanometer-sized pores along the ͓001͔ direction is calculated as a function of pore diameter ͑d p ͒ and pore spacing ͑d s ͒ by employing a molecular dynamics approach. Our results show that ␬ l across pores is smaller than the bulk value by over two orders of magnitude at room temperature, and that it decreases(More)
This paper reports on the detection of nano-scale chemical variations in photosensitive polymers and biological variations in ovarian cancerous tumor cells that have been accomplished for the first time using scanning thermal probes that we have developed. A probe of 250 µm length, 50 µm width, and 3 µm thickness has a measured spring constant of 0.082 N/m.(More)
—This paper investigates the spatial correlation characteristics of multiple antenna arrays deployed in wireless communication systems. First, we derive a general closed-form formula for the spatial correlation function (SCF) of a multiple antenna array with arbitrary array configuration under uniform signal angular energy distribution. Based on this(More)
The successful use of the Design of Experiments (DOE) and Response Surface Modeling (RSM) approaches in an optimization study for a multilayer interdigitated passband filter is presented. The medium of interest is Liquid Crystal Polymer (LCP) and the frequency band is in the 60 GHz range. The two figures of merit chosen are the resonating frequency f o and(More)
Electronic packaging evolution involves systems, technology and material considerations. In this paper, we present a liquid crystal polymer (LCP) based multilayer packaging technology that is rapidly emerging as an ideal platform for low cost, multi-band and reconfigurable RF front-end module integration. LCP's very low water absorption (0.04%), low cost(More)
—This paper deals with adaptive antenna array beamform-ing under spatial information uncertainties including steering angle mismatch, random perturbations in array sensor positions, and mutual coupling between antenna array sensors. To make antenna array beamformers robust against the spatial information uncertainties, we present an iterative method to(More)
—Antenna array beamformers suffer from performance deterioration in the presence of mutual coupling (MC) between array sensors. In this paper, we present a theoretical analysis in terms of the output signal-to-interference-plus-noise ratio (SINR) for the performance of antenna array beamformers under MC effects. Based on the model of a distortion matrix to(More)
This paper presents neural network and genetic algorithm based modeling and design of millimeter wave RF front end circuits. The neuro-genetic design methodology is composed of two stages. Stage one consists of the development of an accurate neural network model for the microwave filters from the measured data. This model can be used to perform sensitivity(More)
The purpose of this study was to improve mapping power and resolution for the QTL influencing carcass quality in Hanwoo, which was previously detected on the bovine chromosome (BTA) 6. A sample of 427 steers were chosen, which were the progeny from 45 Korean proven sires in the Hanwoo Improvement Center, Seosan, Korea. The samples were genotyped with the(More)