• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.4
• /
• pp.184-193
• /
• 2015

Passive Surveillance System based on the TDOA detects the emitter position in the air using TOA of pulses comprising emitter signal from multiple receivers. In case that PRI of pulses from the emitter is not enough big in comparison with the distance among receivers, it causes the ambiguity problem in selecting proper pulse pairs for TDOA emitter geolocation. In this paper, a novel ambiguity resolution method of radar pulses is presented by using genetic algorithm after changing ambiguity problem into optimization problem between TDOA of received pulses from each receiver and emitter position. Simulation results are presented to show the performance of the proposed method.

• Journal of Korean Home Economics Education Association
• /
• v.25 no.3
• /
• pp.105-121
• /
• 2013

This study aimed to investigate the validity and appropriate way of career education according to the integration of home economics subjects, as a way of revitalization of career education in technology and home economics subjects, after the implementation of free semester system. For this goal, the meaning and trend of free semester system, trend of subject-integrated career education, analysis of curriculum in technology home economics education subject, and trend of research about career education in home economics were investigated. The result was as in the following. First, in spite of the ambiguity of the meaning of free semester, the career education will be expanded as the importance of lifelong career education was more and more required. Second, the career paths separated from subjects had problem in its effectiveness, therefore, subject-integrated career education emphasizing on school subjects will become more crucial. Third, it was presented that extracting core achievement standard in subject-integrated career education in technology home economics education according to core achievement standard was critical. For these reasons, the objective and model of career education in home economics education under free semester system were illustrated.

• Journal of Convergence for Information Technology
• /
• v.11 no.11
• /
• pp.17-22
• /
• 2021

Radar signal analysis of electronic warfare is a technique for identifying a radar type by signal parameters(direction, radion frequency, pulse repetition interval, pulse width, scan period..) extracted from a received radar pulse. However as the modern radar and new threat environments is advanced, radar identification ambiguity arises in the process of identifying the types of radars. In this paper, we analyze the problems of the existing method and propose a new method. This technique determines the validity of the scan period by the difference in the arrival time of the radar pulse and the minimum number of scan period discrimination. Experiments proved that the scan cycle results are derived regardless of the RMS((Root Mean Square) of the input amplitude.

• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.17-20
• /
• 2009

최근 신생창업가의 네트워킹 활동이 성공적인 창업을 좌우한다는 선진연구 가능성이 주목받는 가운데, 본 연구는 창업가의 인지적 특성인 자아효능감과 심리적 특성인 모호성 인내가 네트워킹 활동에, 그리고 네트워킹 활동의 구성요소들이 기업성과에 미치는 영향에 대해 탐색적으로 연구하는데 그 주된 목적으로했다. 창업한지 3년 미만의 신생벤처기업의 창업가 156명의 설문지 응답을 표본으로 검증하였다. 연구결과, 첫째, 창업가의 자아효능감은 네트워킹과 창업성과에 각각 유의한 영향을 미치는 것으로 나타났다. 둘째, 모호성 인내는 네트워킹과 창업성과에 모두 유의한 영향을 미치지 않는 것으로 분석되었다. 셋째, 네트워킹 활동은 창업성과에 영향을 미치는 것으로 나타났으며, 네트워킹 활동의 구성요소 중 네트워크 빈도와 신뢰는 창업성과에 유의한 영향을 미치는데 반해, 네트워크 범위는 유의한 영향을 미치지 않는 것으로 분석되었다. 따라서 창업기업의 성과향상을 위해서는 창업가의 심리적 특성 보다는 인지적 특성인 자아효능감이 더 중요하다고 볼 수 있다. 또한 신생벤처 창업가의 네트워킹 활동의 경우 네트워크의 범위를 무리하게 확장하는 것은 기업성과 향상에 부정적 영향을 초래할 수 있다는 실무적 시사점과 함께 연구한계 및 연구방향을 제시하고 있다

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.1
• /
• pp.131-137
• /
• 2023

In this paper, a phase comparison direction finding method of circular array composed of 8 antennas considering polarization characteristics is analyzed. A broadband cavity-backed patch antenna operating in 6 ~ 12 GHz is used, and the antennas are arranged in radial direction to receive various polarization signals. For the phase comparison, widely spaced elements are used to obtain precise DOA(Direction of Arrival), and narrowly spaced elements are used to resolve ambiguity. Two dimensional direction finding is performed for ±20° in both azimuth and elevation, and the DOA error is less than 0.5° and 1.6° near the boresight and the ±15° region, respectively.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2023.07a
• /
• pp.137-140
• /
• 2023

오픈월드 게임에서는 주어진 퀘스트나 미션 이외에도 다양한 자유로운 활동을 할 수 있다. 이로 인해 게임 내 방향성이 불분명해지고, 사용자가 무엇을 해야 하는지 혼란스러워지는 경우가 발생한다. 사용자가 게임을 시작할 때 게임이 제공하는 다양한 옵션과 활동을 살펴보면서 진행 방식을 정하게 된다. 이때 게임이 주어지는 목표나 방향성이 모호하면 사용자는 어떤 것을 해야 하는지 혼란스러워지기 때문에 게임을 즐기는데 있어서 큰 장애물이 된다. 본 논문에서는 다른 온라인게임이나 콘솔게임 같은 경우 명확한 목표를 지정해주지만 오픈월드 게임에서는 자유도라는 무기가 과하면 오히려 독이 될 수 있으므로 이와 같은 문제 해결 방법을 제시해 본다.

• Journal of Digital Convergence
• /
• v.12 no.4
• /
• pp.213-226
• /
• 2014

Previous research on work and life balance mainly focused on workers' passive acceptance of interferences rather than active management of them. However, workers can also actively manage boundaries to enhance work and life balance. To find ways to enhance work and life balance, especially in the context of Smart Work, factors having effects on the work/nonwork interferences and their relationships should be firstly investigated. The results show that in a work domain, both boundary strength at work and job autonomy negatively influence on the nonwork to work interferences; in a nonwork domain, both boundary strength at nonwork and autonomy have negative effects on the work to nonwork interferences.

• Journal of the Korean Society for Precision Engineering
• /
• v.34 no.4
• /
• pp.259-264
• /
• 2017

Spectrally resolved interferometry (SRI) is an attractive technique to measure absolute distances without any moving components. In the spectral interferogram obtained by a spectrometer, the optical path difference (OPD) can simply be extracted from the linear slope of the spectral phase. However, SRI has a fundamental measuring range limitation due to maximum and minimum measurable distances. In addition, SRI cannot distinguish the OPD direction because the spectral interferogram is in the form of a natural sinusoidal function. In this investigation, we describe a direction determining SRI and propose the optimal conditions for determining OPD direction. Spectral phase nonlinearity, caused by a dispersive material, effects OPD direction but deteriorates spectral interferogram visibility. In the experiment, various phase nonlinearities were measured by adjusting the dispersive material (BK7) thickness. We observed the interferogram visibility and the possibility of direction determination. Based on the experimental results, the optimal dispersion conditions are provided to distinguish OPD directions of SRI.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.12 s.354
• /
• pp.16-23
• /
• 2006

This paper presents the development of the fast Direction Finder using direct conversion method, which can intercept for short pulse signal of less' than 1 msec. in RF Down Converter, and CVDF(Correlative Vector Direction Finding) algorithm, which estimates DoA (Direction of Arrival). The configuration and characteristics of direction finder using 5-channel equi-spaced circular array antenna are presented and the direct conversion techniques for removing tuning time using I/Q demodulator are described. The CRLB of our model is derived, the principles of 2 kind of CVDF algorithm are explained and their characteristics are compared with CRLB w.r.t the number of samples and spacing ratio. The RF Down Converter prototype using direct conversion method is manufactured, the 2 kind of CVDF algorithm are applied and their performance are analyzed. Finally it is confirmed the LSE based CVDF algorithm is better than correlation-coefficient based except for ambiguity protection capabilities.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.22 no.3
• /
• pp.684-687
• /
• 1998

The biggest problem common on to all forms of Phase Shift Interferometer is unwrapping the phase. Simple phase unwrapping algorithms assume that every pixel is within radians of its neighbors. If this is true, any reasonable algorithm will return the correct unwrapped phase. If not, correct unwrapped phase will not be obtained. In rough surface, frequently, neighboring pixels have phase steps greater than. This paper proposes the new method which makes phase steps smaller than by sub-pixel movement.