Building a Co-participatory Partnership Framework for School-visit STEAM Outreach Program

( Inae Kang ),( Jungwon Hwang ),( Jin Hye Jang ),( Eunsung Kang ) 한국교육공학회 2016 한국교육공학회 학술대회발표자료집 Vol.2016 No.1

This study aimed to provide a co-participatory partnership framework for a school-visit STEAM outreach program. The framework has been created through a STEAM outreach program practiced between an elementary school and an University hospital, in which 76 students with two teachers, and three medical doctors have participated during the fall semester of 2015. Data analysis collected from interviews and surveys with the participants showed highly positive responses to the program, which, in turn, reflects the usefulness of the framework. The STEAM outreach framework is basically a model of school visit which seems to ensure more possibility of sustaining the outreach program, compared to the models of organization visit more often experienced in most STEAM outreach programs. The framework, on one hand, assumes three pedagogical principles of STEAM (context-based, creative design, affective experience) in developing the STEAM outreach program, and the other hand, suggests three stages of management (planning, designing, and implementing), each of which describes specific roles of the participants, and things to consider for the outreach program management.

Tumor vasodilation by N-Heterocyclic carbene-based nitric oxide delivery triggered by high-intensity focused ultrasound and enhanced drug homing to tumor sites for anti-cancer therapy

Kang, Youngnam,Kim, Jeesu,Park, Junbeom,Lee, Yeong Mi,Saravanakumar, Gurusamy,Park, Kyeng Min,Choi, Wonseok,Kim, Kimoon,Lee, Eunsung,Kim, Chulhong,Kim, Won Jong Elsevier 2019 Biomaterials Vol.217 No.-

<P><B>Abstract</B></P> <P>Nitric oxide (NO) is widely known as an effective vasodilator at low concentrations. Drug delivery systems combined with NO can dilate blood vessels surrounding tumor tissues, and the drug accumulation in tumors is accelerated by the enhanced permeability and retention effect, leading to an improvement in the anti-tumor effect. N-heterocyclic carbene-based NO donors (e.g., 1,3-bis-(2,4,6-trimethylphenyl)imidazolylidene nitric oxide (IMesNO) have been developed for stable NO storing in air and water, and NO release by thermolysis. Herein, we demonstrated on-demand NO release by high-intensity focused ultrasound (HIFU) as a stimulus, which generated high heat and exerted an ablation effect when treated <I>in vivo</I>. We demonstrated IMesNO to be a HIFU-responsive NO donor and its potential application <I>in vivo</I> using IMesNO-loaded micelles. Moreover, IMesNO-loaded micelles mixed with drug-loaded micelles (IMesNO/DOX@MCs) showed acceleration of drug accumulation in tumor sites and enhanced tumor growth inhibition. Thus, our findings suggest a potential clinical bioapplication of NO-releasing drug-loaded micelles owing to the therapeutic function of NO and HIFU treatment for anti-cancer therapy.</P>

Pressure dependence of upper critical fields in FeSe single crystals

Kang, Ji-Hoon,Jung, Soon-Gil,Lee, Sangyun,Park, Eunsung,Lin, Jiunn-Yuan,Chareev, Dmitriy A,Vasiliev, Alexander N,Park, Tuson IOP 2016 Superconductor science & technology Vol.29 No.3

<P>We investigate the pressure dependence of the upper critical fields (<I>μ</I> <SUB>0</SUB> <I>H</I> <SUB>c2</SUB>) for FeSe single crystals with pressure up to 2.57 GPa. The superconducting (SC) properties show a disparate behavior across a critical pressure where the pressure-induced antiferromagnetic phase coexists with superconductivity. The magnetoresistance for <I>H</I>//<I>ab</I> and <I>H</I>//<I>c</I> is very different: for <I>H</I>//<I>c</I>, magnetic field induces and enhances a hump in the resistivity close to the <I>T</I> <SUB>c</SUB> for pressures higher than 1.2 GPa, while it is absent for <I>H</I>//<I>ab</I>. Since the measured <I>μ</I> <SUB>0</SUB> <I>H</I> <SUB>c2</SUB> for FeSe samples is smaller than the orbital limited upper critical field <img ALIGN='MIDDLE' ALT='$({{{H}}^{{\rm{orb}}}}_{{\rm{c}}2})$' SRC='http://ej.iop.org/images/0953-2048/29/3/035007/sustaa1185ieqn1.gif'/> estimated by the Werthamer, Helfand and Hohenberg model, the Maki parameter (<I>α</I>) related to Pauli spin-paramagnetic effects is additionally considered to describe the temperature dependence of <I>μ</I> <SUB>0</SUB> <I>H</I> <SUB>c2</SUB>(<I>T</I>). Interestingly, the <I>α</I> value is hardly affected by pressure for <I>H</I>//<I>ab</I>, while it strongly increases with pressure for <I>H</I>//<I>c</I>. The pressure evolution of the <I>μ</I> <SUB>0</SUB> <I>H</I> <SUB>c2</SUB>(0) for the FeSe single crystals is found to be almost similar to that of <I>T</I> <SUB>c</SUB>(<I>P</I>), suggesting that the pressure-induced magnetic order adversely affects the upper critical fields as well as the SC transition temperature.</P>

Parameter Estimation for Multipath Error in GPS Dual Frequency Carrier Phase Measurements Using Unscented Kalman Filters

Eunsung Lee,Sebum Chun,Young Jae Lee,Teasam Kang,Gyu-In Jee,Jeongrae Kim 대한전기학회 2007 International Journal of Control, Automation, and Vol.5 No.4

This paper describes a multipath estimation method for Global Positioning System (GPS) dual frequency carrier phase measurements. Multipath is a major error source in high precision GPS applications, i.e., carrier phase measurements for precise positioning and attitude determinations. In order to estimate and remove multi path at carrier phase measurements, an array GPS antenna system has been used. The known geometry between the antennas is used to estimate multi path parameters. Dual frequency carrier phase measurements increase the redundancy of measurements, so it can reduce the number of antennas. The unscented Kalman filter (UKF) is recently applied to many areas to overcome some of the limitations of the extended Kalman filter (EKF) such as weakness to severe nonlinearity. This paper uses the UKF for estimating multi path parameters. A series of simulations were performed with GPS antenna arrays located on a straight line with one reflector. The geometry information of the antenna array reduces the number of estimated multipath parameters from four to three. Both the EKF and the UKF are used as estimation algorithms and the results of the EKF and the UKF are compared. When the initial parameters are far from true parameters, the UKF shows better performance than the EKF.

Performance Improvement of Wald Test for Resolving GPS Integer Ambiguity Using a Baseline-Length Constraint

Eunsung Lee,Sebum Chun,Young Jae Lee,Teasam Kang,Gyu-In Jee,Mamoun F. Abdel-Hafez 대한전기학회 2006 International Journal of Control, Automation, and Vol.4 No.3

In this paper, the baseline-length information is directly modeled as a measurement for the Wald test, which speeds up the resolution convergence of the integer ambiguity of GPS carrier phase measurements. The convergent speed improvement is demonstrated using numerical simulation and real experiments. It is also shown that the integer ambiguities can be resolved using only four actual satellite measurements with very reasonable convergence speed, if the baseline-length information is used just like one additional observable satellite measurement. Finally, it is shown that the improvement of convergence speed of the Wald test is due to the increase of the probability ratio with the use of the baseline-length constraint.

Contrast Enhancement Using Dominant Brightness Level Analysis and Adaptive Intensity Transformation for Remote Sensing Images

Lee, Eunsung,Kim, Sangjin,Kang, Wonseok,Seo, Doochun,Paik, Joonki IEEE 2013 IEEE geoscience and remote sensing letters Vol.10 No.1

<P>This letter presents a novel contrast enhancement approach based on dominant brightness level analysis and adaptive intensity transformation for remote sensing images. The proposed algorithm computes brightness-adaptive intensity transfer functions using the low-frequency luminance component in the wavelet domain and transforms intensity values according to the transfer function. More specifically, we first perform discrete wavelet transform (DWT) on the input images and then decompose the LL subband into low-, middle-, and high-intensity layers using the log-average luminance. Intensity transfer functions are adaptively estimated by using the knee transfer function and the gamma adjustment function based on the dominant brightness level of each layer. After the intensity transformation, the resulting enhanced image is obtained by using the inverse DWT. Although various histogram equalization approaches have been proposed in the literature, they tend to degrade the overall image quality by exhibiting saturation artifacts in both low- and high-intensity regions. The proposed algorithm overcomes this problem using the adaptive intensity transfer function. The experimental results show that the proposed algorithm enhances the overall contrast and visibility of local details better than existing techniques. The proposed method can effectively enhance any low-contrast images acquired by a satellite camera and is also suitable for other various imaging devices such as consumer digital cameras, photorealistic 3-D reconstruction systems, and computational cameras.</P>

히스토그램 명세화를 이용한 동시적 변환함수 추정 및 색상 보정

이은성(Eunsung Lee),조두희(Doohee Cho),강원석(Wonseok Kang),하동환(Donghwan Har),백준기(Joonki Paik) 대한전자공학회 2010 대한전자공학회 학술대회 Vol.2010 No.6

기저선 제한조건을 이용한 GPS 반송파 바이어스 오차의 검출확률 향상

이은성(Eunsung Lee),천세범(Sebum Chun),이영재(Young-Jea Lee),강태삼(Teasam Kang),지규인(Gyu-In Jee) 한국항공우주학회 2004 韓國航空宇宙學會誌 Vol.32 No.9

본 논문에서는 기저선 제한조건을 이용하여 GPS 반송파 측정값에 바이어스 존재 여부를 보다 정확하게 판단하는 방법을 확인하고 시뮬레이션을 통하여 이를 분석하였다. 기저선 제한조건은 추가적인 측정값으로 사용되며, 기존의 GPS 반송파 측정 방정식을 확장하는 형태로 사용된다. GPS 반송파 측정값만을 사용하는 경우와 기저선 제한조건을 함께 사용하는 경우에 대하여, 각각 검출확률(Detection Probability)를 계산하고 기저선 제한조건을 사용하는 경우 검출확률이 향상되는 것을 보이게 된다. 기저선 제한조건을 사용하는 것에 대한 장점을 통계적으로 증명하고 시뮬레이션을 통하여 수치적인 결과를 확인한다. A method is suggested for validating the existence of bias error on GPS carrier measurement. The baseline constraint is used as an addition measurement, which augments the original measurement equation. The detection probability is calculated on both cases. The first case is using GPS carrier measurement only, the second case is using GPS carrier and a baseline constraint. The improvement of the detection probability is shown, and the advantage of using baseline constraint is described statistically, the results of the simulation is shown and analyzed.

자세결정시의 GPS 반송파 다중경로 오차 추정

이은성(Eunsung Lee),천세범(Sebum Chun),이영재(Young-Jea Lee),강태삼(Teasam Kang),지규인(Gyu-In Jee) 한국항공우주학회 2005 韓國航空宇宙學會誌 Vol.33 No.3

잘못된 미지정수는 잘못된 위치값을 사용자에게 제공하여 자세결정에 큰 오차를 발생 시킨다. 본 논문에서는 이동하는 항체에 4개 이상의 GPS 안테나를 고정시켜 정확한 자세 결정을 수행할 때 다중경로를 추정하는 방법을 제안하였다. 4개 이상의 GPS 안테나에서 얻은 측정값이 같은 수신기 시계오차를 갖게 되면, 안테나 사이의 기하학적 관계를 이용하여 자세결정을 보다 효과적으로 수행할 수 있다. 안테나 사이의 거리를 반파장으로 만들어 미지정수 검색의 과정 없이 미지정수를 결정하고, GPS 반송파 측정값에 존재하는 다중경로 오차를 추정할 수 있다. 본 논문은 GPS 반송파 측정값의 다중경로 오차를 추정하는 알고리즘을 제시하고 수학적인 증명을 하였으며, 이 결과를 시뮬레이션을 통해 검증 하였다. Incorrect ambiguity integer of GPS make a large error on attitude determination. In this paper one method is suggested for estimating the multipath of GPS carrier measurement while attitude determination. The multi-antenna system consists of 4 antennas have the same clock error help to make attitude determination effectively. If the distance between antennas is a half wavelength, it is not necessary to search the ambiguity integer and the multipath of GPS carrier measurement can be estimated. The results of the simulation are shown and analyzed.

Color Enhancement of Low Exposure Images using Histogram Specification and its Application to Color Shift Model-Based Refocusing

Lee, Eunsung,Kang, Wonseok,Kim, Sangjin The Institute of Electronics and Information Engin 2012 IEIE Transactions on Smart Processing & Computing Vol.1 No.1

An image obtained from a low light environment results in a low-exposure problem caused by non-ideal camera settings, i.e. aperture size and shutter speed. Of particular note, the multiple color-filter aperture (MCA) system inherently suffers from low-exposure problems and performance degradation in its image classification and registration processes due to its finite size of the apertures. In this context, this paper presents a novel method for the color enhancement of low-exposure images and its application to color shift model-based MCA system for image refocusing. Although various histogram equalization (HE) approaches have been proposed, they tend to distort the color information of the processed image due to the range limits of the histogram. The proposed color enhancement algorithm enhances the global brightness by analyzing the basic cause of the low-exposure phenomenon, and then compensates for the contrast degradation artifacts by using an adaptive histogram specification. We also apply the proposed algorithm to the preprocessing step of the refocusing technique in the MCA system to enhance the color image. The experimental results confirm that the proposed method can enhance the contrast of any low-exposure color image acquired by a conventional camera, and is suitable for commercial low-cost, high-quality imaging devices, such as consumer-grade camcorders, real-time 3D reconstruction systems, digital, and computational cameras.