• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.661-666
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• 2009

Modular snake-like robots, which consist of series of modules, are robust for failure and have flexible locomotions for environment. However, they are difficult to control and few efficient and various locomotions are introduced yet. In this paper, GA based phase generation and trajectory generation approaches are implemented and compared for locomotion of snake-like robots and extended for analysis for selections of partial modules. In addition, modeling and simulation environments are implemented in Webots simulator and above GA based experiments for locomotion are executed for KMC snake-like robot.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.3
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• pp.267-286
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• 2017

The main purpose of this paper is to identify the spatiality of North Korea and China border regions through investigating the exceptional characteristics of the regions with the concept of positionality, which allows us to realize the relative position between subject and object. Border regions could be identified appropriately by considering the concept of switching positionality, as it is a kind of multiple space in which its sudden closure and opening should be configured in accordance with geopolitical and geoeconomic changes centering around border line. The main arguments of this research concerned with border regions with the concept of switching positionality are fallen into three. Firstly, changes in border regions should be analyzed by investigating more broader contexts and conjunctural perspectives, and even an internal condition stemmed from locality. Secondly, trajectories of border regions could be analyzed by the assemblages of various powers. Finally, the positionality of economic actors should be examined by identifying dynamic relations between geoeconomics and geopolitics. In particular, the concept of positionality has led to a number of insights into discussions on time-space, and spatiality in relational-dialectical, socio-spatial, and power-topological perspectives. Based upon this concept of positionality, the research has identified exceptional characteristics in North Korea and China border regions. It argues that the exceptionality of the region has stemmed from the intersection between the unstability of geopolitical security and various geoeconomic benefits.

• Journal of Science and Technology Studies
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• v.9 no.2
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• pp.1-27
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• 2009

This study aims at reviewing and assessing the characteristics of the Korean Science, Technology and Innovation(STI) policy of the 2000s. Starting from the 2000s, Korea's STI policy began to show a new look as there was a clear voice calling for the new strategy creating a new technological development path and the scope of the policy was expanded to the social and quality of life issues. "Creation" and "integration" are becoming the key words of the STI policy of Korea. However, these new trends are not easy to be diffused or institutionalized because still there is the legacy of the old practice of the "catch-up" period, which focused on economic development as well as the imitation of advanced technologies. As result, the current period of the 2000s shows characteristics of a transitional period where the past and the future coexist.

• Journal of Broadcast Engineering
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• v.1 no.2
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• pp.85-95
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• 1996

The purpose of this paper Is to propose a dubbed signal time-synchroniztion technique based on the SOLA(Synchronized Over-Lap and Add) method which has been widely used to modify the time scale of speech signal. In broadcasting audio recording environments, the high degree of background noise requires dubbing process. Since the time difference between the original and the dubbed signal ranges about 200mili seconds, process is required to make the dubbed signal synchronize to the corresponding image. The proposed method finds he starting point of the dubbing signal using the short-time energy of the two signals. Thereafter, LPC cepstrum analysis and DTW(Dynamic Time Warping) process are applied to synchronize phoneme positions of the two signals. After determining the matched point by the minimum mean square error between orignal and dubbed LPC cepstrums, the SOLA method is applied to the dubbed signal, to maintain the consistency of the corresponding phase. Effectiveness of proposed method is verified by comparing the waveforms and the spectrograms of the original and the time synchronized dubbing signal.

• Journal of KSNVE
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• v.9 no.1
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• pp.196-205
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• 1999

The existence. bifurcation. and the orbital stability of periodic motions, which is called nonlinear normal mode, in a nonlinear dual mass Hamiltonian system. which has 6th order homogeneous polynomial as a nonlinear term. are studied in this paper. By direct integration of the equations of motion. Poincare Map. which is a mapping of a phase trajectory onto 2 dimensional surface in 4 dimensional phase space. is obtained. And via the Birkhoff-Gustavson canonical transformation, the analytic expression of the invariant curves in the Poincare Map is derived for small value of energy. It is found that the nonlinear system. which is considered in this paper. has 2 or 4 nonlinear normal modes depending on the value of nonlinear parameter. The Poincare Map clearly shows that the bifurcation modes are stable while the mode from which they bifurcated out changes from stable to unstable.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.1
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• pp.47-55
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• 2012

This paper describes the developed HILS and test equipment in order to test the performances of MMW(Millimeter-Wave) seeker which can detect and track a high speed of short-range ballistic missile and aircraft. This system is used to 141 horn antenna array, array switching, and gain and phase control algorithm to simulate various kind of targets and trajectory of high speed and maneuver moving target. In addition, it simulates not only velocity and range for these targets but also clutter and jamming environments. System configuration and implementation and the measurement results of major subsystems such as target motion simulator, simulation signal generator, high speed data aquisition unit, and central control unit are presented. These systems could verify the detection and tracking performance of MMW seeker through dynamic real-time test based on simulation flight scenario.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.29-35
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• 2008

In this paper, The author present a load current feed-forward compensator by method that improve voltage controller of Step-down Chopper to get stable output voltage to sudden change of load current. To confirm the characteristics of a presented load current feed-forward compensator compared each transfer function of whole system that load current feed-forward compensator is added with transfer function of whole system that existent voltage controller is included using Mason gains formula in Root locus and Bode diagram. As a result the pole of system is improved, extreme point of the wave and system improves, and size of peak value and phase margin of break frequency in resonance frequency confirmed that is good. Therefore, presented control technique could confirm that reduce influence by perturbation and improves stationary state and dynamic characteristics in output of Step-down Chopper.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.1
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• pp.25-38
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• 1993

Numerical models of directional wave spectra for the analysis of offshore structural cable responses are verified. Alternative spreading models are used to predict wave-induced flows in water and for mooring systems. Hydrodynamic wave forces upon cable are estimated. using a Morison formula encompassing considerations for drag and for inertial forces both parallel and tangential to the slope of the cable. Numerical analysis for directional random waves. including consideration of displacement and velocity, trajectory, phase plane response. and tension are shown for mooring system cable responses at both the tether point for a buoy and at the anchor point. The effects of wave forces far different drag coefficients, various significant wave heights, and selected wave parameters are considered in the analysis. For the specific systems considered in the examples, it is demonstrated that wave period and height as well as wave spreading function parameters and drag coefficients, have an important effect upon the dynamic responses of the cable-buoy systems.

• Korean Architects
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• s.597
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• pp.22-27
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• 2018

"사실 국가건축정책위원장 책임을 떠안는 것에 고민을 많이 했습니다. 작금 건축의 본질에 관해 꽤 진지하게 논하는 결정권자들이 많아진 상황에서 직을 맡은 이상 그냥 시간만 보내진 않을 겁니다. 평소 생각한 건축계의 부족한, 불합리한, 불비한 부분을 임기 중 완전히 고치진 못한다 하더라도 시작은 해놓고 끝내려 합니다." 작년 4월 취임한 승효상 대통령소속 국가건축정책위원장이 국내 건축계 현안에 대한 생각과 앞으로의 계획을 설명했다. 그가 걸어온 삶의 궤적에는 건축의 공공성 문화적 가치라는 단어들이 새겨져 있으며, 이는 그가 활동해 온 건축계 여러 운동 모임에서도 살펴볼 수 있다. 지식인으로서 마땅히 지녀야 할 건축사(Architect)의 책무에 관해서는 쓴소리도 서슴지 않았던 그다. 2014년 서울시 '초대 총괄건축가'로 선임돼 서울시의 도시정책과 건축문화, 공공 공간조성 등 도시계획 전반에 대해 역할을 했다면, 이젠 국가 건축정책의 목표와 관계 부처간 건축정책의 심의.조정까지 그 역할범위가 커졌다. 필드의 건축사라면 승효상 국가건축정책위원장에게 기대하는 바가 큰 게 사실이다. 실제 그의 취임 후 정부 내 국건위의 위상은 과거와 달라졌으며, 작년 9월 4일에는 문재인 대통령이 서울 은평구 구산동 도서관마을에서 열린 '대한민국 국민생활 SOC현장 방문, 동네 건축현장을 가다' 행사에 참석해 도서관, 체육관, 경로당 등 '생활 SOC 혁신의지'를 강조해 눈길을 끌었다. 최근 정부세종신청사 설계공모 관련 논란에는 "국토부에 소관 설계공모 규정을 고쳐야 함을 권고했다. 고칠 거다! 안 고치면 안 되게 돼 있다!"며 목소리에 힘을 주어 재차 강조했다. 제5기 대통령소속 국가건축정책위원장으로 선임돼 지난해 4월부터 역할을 해온 승효상 건축사를 종로구 동숭동 (주)종합건축사사무소 이로재(履露齋)에서 만났다.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.31-50
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• 2004

With the growth of wireless communication networks and mobile devices taking in GPS, Location-Based Service(LBS) is becoming an integral part of mobile applications. LBS can deal with location-aware features such as persons holding mobile phones or vehicles equipped with GPS, and provide the users with the location information of the features. Thus it is necessary to develop moving object database systems to store, manage, and query moving objects which change their locations continuously as time passes. In this paper, we design and implement a query processing component which deals with moving objects as a key data type. For this component, we define a new SQL-like query language(called MOQL) and as a consequence, design and implement modules that analyze and execute queries. It supports various types of operators that process range queries, infer topological relations, compute trajectories, and find k-nearest neighbors. It can be used as a subsystem if other application systems which deal moving objects and also supports ADO.NET interface that can be used to interact end-users.