중대형 터치 디스플레이 환경에 적합한 다중 사용자용 GUI

김태형(Taehyoung Kim),김인혁(Inhyeok Kim),김정한(Junghan Kim),엄영익(Young Ik Eom) 한국정보과학회 2015 한국정보과학회 학술발표논문집 Vol.2015 No.6

Intel VT 기술을 이용한 Xen 기반 동적 악성코드 분석 시스템 구현 및 평가

김태형(Taehyoung Kim),김인혁(Inhyuk Kim),엄영익(Young Ik Eom),김원호(Won Ho Kim) 한국정보과학회 2010 정보과학회논문지 : 시스템 및 이론 Vol.37 No.5

악성코드를 분석하기 위한 기법에는 다양한 방법들이 존재한다. 하지만 기존의 악성코드 분석 기법으로는 악성코드들의 동작들을 정확하게 분석하는 것이 점점 어려워지고 있다. 특히, 분석 시스템들이 악성코드의 안티-디버깅 기술에 의해 감지되기 쉽고, 실행속도 등 여러 가지 한계점을 보임에 따라 이를 해결할 수 있는 분석 기법이 요구되고 있다. 본 논문에서는 동적 코드 분석을 위한 기본 요구사항인 명령어 단위 분석 및 메모리 접근 추적 기능을 제공하는 동적 코드 분석 시스템을 설계 및 구현한다. 그리고 DLL 로딩 추적을 통한 API 호출 정보를 추출하여, 다양한 실행 코드들을 분석 할 수 있는 기반 환경을 구축한다. 제안 시스템은 Intel의 VT 기술을 이용하여 Xen 기반으로 전가상화 환경을 구축하였으며, 게스트에서는 윈도우즈 XP가 동작할 수 있도록 하였다. 제안 시스템을 이용하여 대표적인 악성코드들을 분석해 봄으로써 제안 시스템 각각의 기능들의 활용을 살펴보고, 제안 시스템이 악성코드들을 정확하게 분석및 탐지함을 보여준다. There are several methods for malware analyses. However, it is difficult to detect malware exactly with existing detection methods. Especially, malware with strong anti-debugging facilities can detect analyzer and disturb their analyses. Furthermore, it takes too much time to analyze malware. In order to resolve these problems of current analyzers, more improved analysis scheme is required. This paper suggests a dynamic binary instrumentation which supports the instruction analysis and the memory access tracing. Addtionally, by supporting the API call tracing with the DLL loading analysis, our system establishes the foundation for analyzing various executable codes. Based on Xen, full-virtualization environment is built using Intel's VT technology. Windows XP can be used as a guest. We analyze representative malware using several functions of our system, and show the accuracy and efficiency enhancements in binary analyses capability of our system.

클라우드 컴퓨팅 환경에서 보안성 향상을 위한 로컬 프로세스 실행 기술

김태형(Taehyoung Kim),김인혁(Inhyuk Kim),김정한(Junghan Kim),민창우(Changwoo Min),김지홍(Jee-hong Kim),엄영익(Young Ik Eom) 한국정보보호학회 2010 정보보호학회논문지 Vol.20 No.5

기존 클라우드 환경에서는 어플리케이션의 수행이 원격지 클라우드 서버에서 이루어지며, 해당 어플리케이션이 사용하는 물리 메모리, CPU 등 컴퓨팅 자원 역시 원격지 클라우드 서버에 존재한다. 따라서 원격지 서버가 보안 위협에 노출될 경우, 해당 환경에서 실행되는 모든 어플리케이션들이 보안 위협에 의해 영향 받을 수 있다. 특히, 악의적인 클라우드 서버 관리자에 의한 보안 위협으로 인하여, 비즈니스 모델로 많은 이점이 있음에도 불구하고 개인 및 기업 환경에서 클라우드 서비스를 도입하는데 어려움을 겪고 있다. 본 논문에서는 기존 클라우드 컴퓨팅 환경의 취약점을 근본적으로 해결할 수 있는 로컬 프로세스 실행 기술을 제안한다. 이를 통해, 기밀 데이터를 클라우드 서버가 아닌 로컬에 둘 수 있게 되어, 클라우드 서버에서 발생 가능한 보안 위협으로부터 기밀 데이터를 보호할 수 있게 된다. 즉, 보안 데이터를 사용하는 어플리케이션의 경우, 로컬 프로세스 실행 기술을 이용하여 원격지 서버가 아닌 로컬의 컴퓨팅 자원을 사용하여 실행할 수 있도록 설계한다. 이에 따라 보안 프로세스가 사용하는 자원들이 물리적으로 로컬에 존재하므로 원격지 서버의 취약성 문제를 해결할 수 있다. In the current cloud environments, the applications are executed on the remote cloud server, and they also utilize computing resources of the remote cloud server such as physical memory and CPU. Therefore, if remote server is exposed to security threat, every applications in remote server can be victim by several security-attacks. Especially, despite many advantages, both individuals and businesses often have trouble to start the cloud services according to the malicious administrator of the cloud server. We propose a security-enhanced local process executing scheme resolving vulnerability of current cloud computing environments. Since secret data is stored in the local, we can protect secret data from security threats of the cloud server. By utilizing computing resource of local computer instead of remote server, high-secure processes can be set free from vulnerability of remote server.

북한의 장기 경제성장률 및 국민소득 추정: 1956~1989년

조태형 ( Taehyoung Cho ),김민정 ( Minjung Kim ) 한국경제학회 2021 經濟學硏究 Vol.69 No.1

본고는 1956~89년중 북한의 장기 경제성장률을 추정한 것이다. 곡물, 석탄, 철강, 전력, 시멘트 등 주요 품목의 생산량 정보를 역사적으로 재구성하여 농림어업, 광업, 경공업, 중화학공업, 전기가스수도업, 건설업, 정부서비스업 등 7개 산업의 성장률을 추정한 다음, 연쇄라스파이레스 지수공식에 의거하여 전체 경제성장률을 산출하였다. 그 결과, 1956~89년중 북한의 경제성장률은 연간 4.7%로 추정되었다. 이는 기존의 대표적 연구인 Kim, Kim, and Lee(2007)의 추정치 4.2%와 대체로 비슷한 수준이었다. 시기별로 보면 1950년대 후반에는 연간 13.8%의 고성장을 달성한 반면, 1960년대 들어 4%대로 낮아진 데 이어 1970~80년대에는 2%대의 저성장이 지속되었다. 즉, 1990년 이전 북한의 경제성장은 ‘일회성 고성장(one big jump)’으로 해석할 수 있다. 산업별로 보면, 1956~89년에 걸쳐 광공업이 연간 7.3%의 높은 성장률을 보인 반면, 농림어업과 서비스업은 각각 2.5% 및 4.6%로 낮은 성장률을 보였는데, 이러한 광공업 중심의 성장으로 인해 북한경제는 공업부문에 대한 과잉 투자와 산업간 불균형이 초래되었다. 한편, 미달러화 기준 1인당 실질GNI를 추정하여 남북한 소득을 비교한 결과, 남한의 1인당 소득은 1960년대 중후반 북한을 앞지른 것으로 평가되었다. 아울러 북한의 1인당 실질GDP 성장률을 사회주의국가와 비교해 보았을 때, 북한의 성장실적은 상대적으로 더욱 부진했다. This study estimates North Korea’s long-term economic growth rate from 1956 to 1989. After reconstructing production data series for major products such as grain, fabrics, coal, steel, electrical power, cement, etc., each industry’s GDP growth rate is estimated by linking relevant production data to that specific industry’s added value. Seven industries are considered: agriculture, forestry & fishing; mining; light industry; heavy chemical industry; electricity, gas & water supply; construction; and government services. Based on industry-specific growth rates, the growth rate for the total economy is computed using the chained Laspeyres index number formula. As a result, the North Korean economy is estimated to have grown on average at 4.7% annually from 1956 to 1989. This is roughly similar to the 4.2% for the same period suggested by Kim, Kim, and Lee (2007), a representative study in the field. By period, the economy achieved a high annual growth rate of 13.8% in the late 1950s, while it fell to the 4-5% range in the 1960s and further diminished to grow at a rate of 2-3% in the 1970s and 1980s. In other words, the economic growth of North Korea before 1990 can be interpreted as “one big jump.” By industry, mining and manufacturing grew at 7.3% annually over the whole period, while agriculture, forestry & fishing and services grew at 2.5% and 4.6%, respectively. The mining and manufacturing-centered growth in the economy resulted in excessive investment in the same industries and an imbalance in growth among all the industries. Meanwhile, this paper shows that South Korea’s per capita income, in terms of real GNI denominated in U.S. dollars, is estimated to have surpassed that of North Korea in the mid- to late 1960s. In addition, North Korea’s real GDP per capita grew relatively sluggishly compared to other socialist country cases.

도로변 초미세먼지의 실시간 질량농도 및 부피농도 측정을 이용한 시간별 밀도 분석-광흡수 eBC에 대한 OPS 보정 중심

김은영(Eunyoung Kim),서석준(Seokjun Seo),김선문(Sunmoon Kim),정성운(Sungwoon Jung),이용민(Yongmin Lee),오세호(Sea-Ho Oh),박규태(Gyutae Park),김경훈(Kyunghoon Kim),김정화(Jounghwa Kim),홍유덕(Youdeog Hong),이태형(Taehyoung Lee),배민석(Mi 한국대기환경학회 2018 한국대기환경학회지 Vol.34 No.6

Scaling Laws of Optimal Training Lengths for TDD Massive MIMO Systems

Kim, Taehyoung,Min, Kyungsik,Jung, Minchae,Choi, Sooyong IEEE 2018 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY Vol.67 No.8

<P>In this study, the scaling laws of optimal training lengths were investigated for time-division duplexing massive multiple-input multiple-output systems. First, the generalized asymptotic achievable rate was derived by taking into account both uplink and downlink training. From the general form, the achievable rates of zero-forcing (ZF) and matched filter (MF) precoders are directly obtained by using the mean and variance of the effective channel. Then, we analyzed the rate gaps of ZF and MF with respect to uplink and downlink training, respectively. According to the analysis of rate gaps, it is shown that the achievable rates are more dominated by the uplink training than downlink training for both ZF and MF. The joint optimization problem for training lengths maximizing the spectral efficiency is formulated as a function of rate gaps. To study the scaling of optimal training lengths with the system parameters, we derived the optimal training lengths as a closed-form expression by using an approximation for the logarithm function. From the analysis, it is shown that the optimal training lengths decrease as the number of antennas increases, and increase as the coherence block length increases. In addition, the optimal training lengths increase as the transmit power increases for ZF, whereas it does not change for MF. Finally, we investigated the superior region for noncoherent detection (which means only statistical information is used for demodulation without downlink training) with the system parameters by comparing the spectral efficiency with and without downlink training.</P>

Polyacetylene polyelectrolyte via the non-catalyst polymerization of 2-ethynylpyridine using heptafluorobenzyl iodide

Taehyoung Kim,Sung-Ho Jin,Jongwook Park,Kwon Taek Lim,Sang Youl Kim,Yeong-Soon Gal 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.87 No.-

A new ionic polyacetylene having perfluorinated benzyl substituent, poly(2-ethynyl-N-heptafluor-obenzylpyridinium iodide), was synthesized via the direct polymerization of the quaterinazed acetylenicpyridinium monomers. The polymerization proceeded homogeneously without any additional initiatoror catalyst to give a moderate yield of polymer. The results of instrumental analyses on the molecularstructure of polymer revealed that the polymer have polyacetylene backbone system with Nheptafluorobenzylicpyridiniumiodide as substituent. The photoluminescence (PL) spectra of polymerexhibited that the PL peak is located at 550 nm, corresponding to a photon energy of 2.26 eV. Theirreversible electrochemical behaviors of polymer between the doped and undoped peaks were observedin the cyclic voltammograms of polymer. The initial oxidation and reduction of poly(EHFBPI) occurred at0.53 V and -0.75 V (vs Ag/AgNO3). HOMO level of poly(EHFBPI) was 5.27 eV.

Cortical representation of musical pitch in event-related potentials

Taehyoung Kim,Miyoung Chung,Eunju Jeong,Yang Seok Cho,Oh-Sang Kwon,Sung-Phil Kim 대한의용생체공학회 2023 Biomedical Engineering Letters (BMEL) Vol.13 No.3

Neural coding of auditory stimulus frequency is well-documented; however, the cortical signals and perceptual correlates of pitch have not yet been comprehensively investigated. This study examined the temporal patterns of event-related potentials (ERP) in response to single tones of pitch chroma, with an assumption that these patterns would be more prominent in musically-trained individuals than in non-musically-trained individuals. Participants with and without musical training (N = 20) were presented with seven notes on the C major scale (C4, D4, E4, F4, G4, A4, and B4), and whole-brain activities were recorded. A linear regression analysis between the ERP amplitude and the seven notes showed that the ERP amplitude increased or decreased as the frequency of the pitch increased. Remarkably, these linear correlations were anti-symmetric between the hemispheres. Specifically, we found that ERP amplitudes of the left and right frontotemporal areas decreased and increased, respectively, as the pitch frequency increased. Although linear slopes were significant in both groups, the musically-trained group exhibited marginally steeper slope, and their ERP amplitudes were most discriminant for frequency of tone of pitch at earlier latency than in the non-musically-trained group (~ 460 ms vs ~ 630 ms after stimulus onset). Thus, the ERP amplitudes in frontotemporal areas varied according to the pitch frequency, with the musically-trained participants demonstrating a wider range of amplitudes and inter-hemispheric anti-symmetric patterns. Our findings may provide new insights on cortical processing of musical pitch, revealing anti-symmetric processing of musical pitch between hemispheres, which appears to be more pronounced in musically-trained people.

Packet transmitter for body channel communication

Taehyoung Kim,Gunhee Han 대한전자공학회 2019 대한전자공학회 학술대회 Vol.2019 No.6

다수의 탄성지지대 위를 축방향으로 이동하는 보 구조물의 동특성 해석

김태형(Taehyoung Kim),이우식(Usik Lee) 한국철도학회 2002 한국철도학회 학술발표대회논문집 Vol.- No.-

This paper investigates the dynamic characteristics of a beam axially moving over multiple elastic supports. The spectral element matrix is derived first for the axially moving beam element and then it is used to formulate the spectral element matrix for the moving beam element with an interim elastic support. The moving speed dependance of the eigenvalues is numerically investigated by varying the applied axial tension and the stiffness of the elastic supports. Numerical results show that the fundamental eigenvalue vanishes first at the critical moving speed to generate the static instability.