메타버스 기반 상담 에이전트와 사용자의 자기노출에 대한 제언

이은성(Eunsung Lee),박윤정(Younjung Park),정민웅(Minwoong Chung),임인재(Injae Im),김소영(Soyoung Kim),이서진(Seojin Lee),이세영(Seyoung Lee),금희조(Heejo Keum) 한국HCI학회 2024 한국HCI학회 학술대회 Vol.2024 No.1

최근 정신건강의 악화가 주요 사회문제로 대두되면서 비대면 방식의 인공지능 정신건강 상담 에이전트의 필요성이 높아지고 있다. 정신건강 상담에 따른 효과를 극대화하기 위해서는 무엇보다 피상담자의 자기노출이 필수적이다. 하지만 그동안의 심리상담 자기노출에 관한 연구는 주로 대면 방식의 상담을 대상으로 이루어졌고, 인공지능 상담 에이전트에 관한 연구는 여전히 초기 단계에 머무르고 있다. 또한 인공지능 상담 에이전트 연구이더라도 대부분 텍스트화된 챗봇 형태로 진행되었으며, 몰입감이 높은 가상환경에서의 연구는 상대적으로 매우 적은 실정이다. 이에 따라 본 논문은 메타버스 환경 내 상담 에이전트와 사용자 간의 상호작용 속에서 사용자의 자기노출에 영향을 미치는 요소를 파악하고자 하였다. 구체적으로, 기존 선행 연구에서 대면 상담 중 자기노출을 높이기 위해 사용된 변수에 대한 분석을 진행하였다. 또한 메타벅스 환경에서 자기노출이 발현되는 상황이 텍스트 기반의 챗봇 에이전트를 향한 자기노출 상황과는 어떻게 다른지에 대해 살펴보았다. 이러한 분석을 바탕으로 본 연구는 메타버스 환경에서의 상담 에이전트를 실제 구현하였다. 본 논문은 피상담자의 자기노출을 높이기 위해서 가상환경에서의 인공지능 상담 에이전트가 향후 어떻게 디자인되고 발전되어야 하는지에 대한 시사점을 제공한다는 연구 의의가 있다.

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.

About naked fluoride

Lee, Eunsung 대한방사성의약품학회 2018 Journal of radiopharmaceuticals and molecular prob Vol.4 No.2

Fluoride is one of most important atoms for both clinical and pharmaceutical usage. Associated with such a strong need, $^{18}F$-fluoride has been widely used as an essential radioisotope. The fluoride always suffers from strong solvation effects through strong hydrogen bonding, which reduce the reactivity of fluoride anion. To enhance the reactivity, the concept of naked fluoride was introduced in the fluorination field. In this essay, I will briefly describe the history of naked fluoride concept and development of naked fluoride sources.

Antenna Placement Optimization for Distributed Antenna Systems

Eunsung Park,Sang-Rim Lee,Inkyu Lee IEEE 2012 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.11 No.7

<P>In this paper, we propose new algorithms to determine the antenna location for downlink distributed antenna systems (DASs) in single-cell and two-cell environments. We consider the composite fading channel which includes small and large scale fadings. First, for the single-cell DAS, we formulate the optimization problem of distributed antenna (DA) port locations by maximizing the lower bound of the expected signal to noise ratio (SNR). In comparison to the conventional algorithm based on the squared distance criterion which requires an iterative method, our problem generates a closed form solution. Next, for the two-cell DAS, we propose a gradient ascent algorithm which determines the optimum DA locations by maximizing the lower bound of the expected signal to leakage ratio (SLR). In our work, we consider selection transmission, maximal ratio transmission and zero-forcing beamforming (ZFBF) under sum power constraint and study equal gain transmission and scaled ZFBF under per-antenna power constraint. Simulation results show that our proposed algorithms based on both the SNR and the SLR criteria offer a capacity gain over the conventional centralized antenna systems.</P>

A Study for Composition and Comparison of the Music Perception Tests for Normal Hearing and Cochlear Implant Users

Eunsung Lee,Yerim Shin,Sungmin Jo,Jinsook Kim 한국청각언어재활학회 2021 Audiology and Speech Research Vol.17 No.3

Purpose: The aim of this study was to compose the test for music perception and analyze the characteristic of cochlear implant users’ music perception. Methods: The test was made up with the pitch, melody, and timbre factors, using three low and high frequencies, six music genres, and four types of musical instruments correspondingly. The tests were conducted to 10 normal-hearing (NH) young adults and 10 young cochlear-implant (CI) users. Results: All the music perception tests showed significant differences between NH and CI group [F(1, 4) = 0.018, p = 0.019]. In the pitch test, CI group showed significantly lower correction rate(51.3%) than NH group (82.7%) did with higher correction rates in low frequencies. In the melody test, CI group showed significantly lower correction rate (29.7%) than NH group (95.8%) did with the highest performance in folk songs (51.7%). In the timbre test, CI group showed significantly reduced performance (22.5%) than NH group (65.8%) did. For both CI and NH groups, the pitched percussion showed the highest scores (45% and 100%) while the woodwind showed the lowest scores (13.3% and 48.3%). Conclusion: Out of three tests, CI group showed better performance in pitch perception than melody and timber perception. CI group showed better performances in low pitch sounds, melodies of familiar genre, and sound of pitched percussion instruments’ timber showing complicated music perception ability. To enhance the music perception ability for CI users by aural rehabilitation, more specified and systematic music perception test material should be developed.

Antitumor Effect of Metformin in Combination with Binimetinib on Melanoma Cells

Lee, Eunsung,Kwon, Yongjae,Kim, Jiwon,Park, Deokbae,Lee, Youngki The Korean Society of Developmental Biology 2021 발생과 생식 Vol.25 No.2

Cutaneous melanoma is a fatal disease for patients with distant metastasis. Metformin is the most widely used anti-diabetic drug, and proved to suppress cell proliferation and metastasis in diverse cancers including melanoma. We previously reported that MEK inhibitor trametinib increases the expression of epithelial-mesenchymal transition (EMT) regulators and melanoma cell motility, which are suppressed by addition of metformin in A375 melanoma cells. To confirm our findings further, we first evaluated the effect of metformin in combination with another MEK inhibitor binimetinib on cell viability in G361 melanoma cells. We then investigated whether binimetinib affects the expression of EMT regulators and cell motility. We finally monitored the effect of metformin on binimetinib-induced cell migration. Cell viability assay showed that combination index (CI) value at ED₅₀ is 0.80, suggesting synergy for the combination of metformin with binimetinib. Our results also revealed that binimetinib increased the expression of EMT regulators such as integrin αV, fibronectin and slug, which correlate well with the enhanced cell migration in wound healing assay. Metformin, on the contrary, suppressed the expression of sparc, integrin αV, fibronectin and N-cadherin with the reduced cell motility. The combination treatment showed that metformin counteracts the binimetinib-induced increase of cell motility. Overall, these results suggest that metformin with binimetinib might be useful as a potential therapeutic adjuvant against cell survival and metastatic activity in melanoma patients.

Reduced Pyronin B as a solution-processable and heating-free n-type dopant for soft electronics

Lee, Eun Kwang,Kim, Yonghee,Back, Jisu,Lee, Eunsung,Oh, Joon Hak The Royal Society of Chemistry 2018 Journal of Materials Chemistry C Vol.6 No.25

<P>Air-stable and heating-free doping processes are highly desirable for realizing advanced flexible electronics on plastic substrates. A synthetic protocol for a high-performance n-type organic dopant using an organic cationic dye, Pyronin B, <I>via</I> a simple chemical reduction method with NaBH4 in various organic non-polar solvents is developed, in which the cationic dye Pyronin B is transformed into its leuco form. The reduced Pyronin B (rPyB, leuco form) spontaneously interacts with carbon nanomaterials, such as graphene and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), <I>via</I> hydride-mediated electron transfer doping, which is confirmed by electron spin resonance (ESR) analysis. After coating rPyB onto graphene, the non-polar solvents are removed by simple evacuation (∼1 × 10<SUP>−3</SUP> Torr) without an annealing step. The work function of graphene is reduced from 4.52 eV to 3.98 eV after doping. Multiple coatings of rPyB on graphene field-effect transistors (FETs) result in air stability for 90 days under ambient conditions. Selective n-type doping using a polydimethylsiloxane (PDMS) stamp and rPyB has also been performed on a large-area 16 × 16 graphene FET array. Our findings demonstrate a viable methodology for the cost-effective synthesis of an n-type dopant and its application in soft electronics.</P>

Depth-based defocus map estimation using off-axis apertures.

Lee, Eunsung,Chae, Eunjung,Cheong, Hejin,Jeon, Semi,Paik, Joonki Optical Society of America 2015 Optics express Vol.23 No.17

<P>This paper presents a depth-based defocus map estimation method from a single camera with multiple off-axis apertures. The proposed estimation algorithm consists of two steps: (i) object distance estimation using off-axis apertures and (ii) defocus map estimation based on the object distance. The proposed method can accurately estimate the defocus map using object distances that are well-characterized in a color shift model-based computational camera. Experimental results show that the proposed method outperforms the state-of-the-art defocus estimation methods in the sense of both accuracy and the estimation range. The proposed defocus map estimation method is suitable for multifocusing, refocusing, and extended depth of field (EDoF) systems.</P>

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>

Fast Motion Deblurring Using Sensor-Aided Motion Trajectory Estimation

Lee, Eunsung,Chae, Eunjung,Cheong, Hejin,Paik, Joonki Hindawi Publishing Corporation 2014 The Scientific World Journal Vol.2014 No.-

<P>This paper presents an image deblurring algorithm to remove motion blur using analysis of motion trajectories and local statistics based on inertial sensors. The proposed method estimates a point-spread-function (PSF) of motion blur by accumulating reweighted projections of the trajectory. A motion blurred image is then adaptively restored using the estimated PSF and spatially varying activity map to reduce both restoration artifacts and noise amplification. Experimental results demonstrate that the proposed method outperforms existing PSF estimation-based motion deconvolution methods in the sense of both objective and subjective performance measures. The proposed algorithm can be employed in various imaging devices because of its efficient implementation without an iterative computational structure.</P>