• 융합보안논문지
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• 제20권1호
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• pp.77-84
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• 2020

북한은 소형무인기를 2014년부터 여러 차례 침투시켰으나, 우리는 탐지/식별, 타격을 할 수 있는 시스템의 부재로 인하여 즉각적인 대응을 하지 못하였다. 지금까지 북한의 항공기는 지형추적 및 지형회피를 통해 레이더와 초병의 육안에 관측되지 않기 위해서 능선을 따라 회피 침투하여 목표물을 타격하고 복귀하는 것으로 인식되었으나 북 소형무인기는 교리적인 요소를 완전히 벗어나서 예상치 못한 고도로 레이더의 탐지를 회피하여 침투함으로서 대공방어의 문제를 야기 시켰다. 북 소형무인기 대응의 문제점 해결을 위해 M&S를 활용한 전투실험을 통해 소형무인기 탐지레이더와 식별 시 즉각 타격할 수 있는 신개념의 무기체계 개발과 탐지/식별과 타격을 동시에 할 수 있는 C2A체계를 활용하여 위협을 최소화하고, 장비 전력화와 연구를 위한 전문 연구 조직 편성으로 위협을 대비하여야 하겠다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.163-168
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• 2006

In a micro-unit of electronic-machine, vibration can be excited by a small impact, and this vibration acts as a fatigue load. To measure the vibration effect on the micro unit, a micro dynamic tester is needed to test a micro specimen. In this paper, it has confirmed a movement of the PZT(piezo actuator) to use a sine signal. And, it has confirmed a fracture of specimens by using a tension-tension input signal in PZT. A metal-material property in the micro scale has been tested to compare with the macro scale. A fatigue test has been conducted by using PZT actuator to give a bending-tension effect.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1999년도 국제 심포지엄 Proceedings of International Symposium on 친환경농업과 기계화방향
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• pp.53-80
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• 1999

Productivity and environmental conservation in nowadays trade-off and serious problem in agriculture. Precision farming is developing for solving the trade-off problem using systems approach and variable management. The systems approach is attributed to aiming at information-oriented agriculture, environmental-friendly sustainable agriculture, and complex system optimization . The variable management is composed of describing variability , variable-rate technology and decision support system. Three levels of technology development and three farming strategies are introduced for having a prospect. Describing the variability is the first step to promote it. Precision farming could be available for small scale farming as well as big scale farming. Paddy field precision farming will undergo in its distinctive way.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1778-1783
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• 2000

When visual intrusion is an important factor, it is desirable to find alternative methods of improving the insertion loss of a noise barrier without increasing the height. Therefore, the primary object of the work attenuates the noise due to transport vehicle by small interference device installed at noise barrier edge. In this paper the performance of noise barriers with attached interference device, in terms of shape, absorptive material and split panel, are examined using the boundary element approach. Also, the scale models are moanted in an anechoic chamber and the frequency of the sound sources are appropriately scaled to simulate full scale site conditions. Lastly, experimental measurements of the designs are executed for a range of frequencies and receiver positions, and are compared with the results of numerical modeling.

• 천문학회보
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• 제43권1호
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• pp.35.2-35.2
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• 2018

Magnetic fields in clusters of galaxies play a critical role in shaping up the intracluster medium. Their existence has been established through observations of synchrotron emission, especially from radio relics and halos, as well as observations of rotation measure. In the so-called Sausage relic, which is one of Mpc-size giant radio relics detected in the outskirts of merging clusters, for instance, the magnetic fields are believed to have a few ${\mu}G$ strength and a Mpc scale. The observed magnetic fields are conjectured to be produced by the process of small-scale turbulence dynamo. To investigate the dynamo origin, we simulate the development of turbulence and the follow-up amplification of magnetic fields in galaxy clusters using a three-dimensional magnetohydrodynamical(MHD) code. Turbulence is induced in highly stratified backgrounds expected in clusters, and driven sporadically mimicking major mergers. We here present preliminary results, aiming to answer whether the turbulence dynamo scenario can explain observed magnetic fields in clusters of galaxies.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.1117-1125
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• 1996

A low-cost and precise metering device, which is suitable to automatic mixing of nutrient-solution for hydroponic culture, was developed for small-scale growers. The metering accuracy of the metering device developed was compared with commercial metering pumps. The mixing performance through the control of EC and pH was also evaluated. The accuracy of the metering device in terms of the full -scale error was $\pm$0.3% , which was much better compared to $\pm$2.45% and $\pm$1.38% for the two types of commercial metering pumps. The mixing system of nutrient-solution with the metering device showed a satisfactory control performance with the accuracies of $\pm$0.05mS/cm and$\pm$0.2pH for EC and pH, respectively.

• International Journal of Railway
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• 제4권1호
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• pp.5-11
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• 2011

The purpose of the present study is to develop conceptual design of a railway vehicle simulator based on a scaled model. Although the scaled simulator is limited in its ability to manipulate the full dynamics of a full-size railway vehicle, it has been known to have an advantage in that it could provide means of testing the fundamental dynamic behavior within a limited laboratory space and at low operation cost. The present study proposes a design strategy for a simulator so that a small scaled roller rig could be fabricated and operated in laboratory setting based on the design philosophy. The data obtained from experimental testing using a scale model can be used to verify and interpret the dynamic performance of full-scale railway vehicle by applying appropriate non-dimensional analysis.

• KDI Journal of Economic Policy
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• 제43권4호
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• pp.23-44
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• 2021

This research attempts to provide an in-depth analysis of the public perceptions of inter-Korean economic cooperation. KDI survey data with a sample size of 1,000 were subjected to empirical analyses. By means of ordered logit estimations, we derive the following results. First, there is a significant effect of age on economic cooperation perceptions, where younger generations tend to be more negative. Second, the group who has positive view on the economic cooperation tends to prefer large-scale, domestic-entity-funded cooperation projects, whereas the group who has negative view tends to prefer small-scale projects and projects funded by international organizations. According to these results, prioritizing trade with the involvement of international organizations is likely to be an effective measure to alleviate potential political constraints and to achieve sustainable long-run economic cooperation systems when pursuing the economic cooperation.

• 천문학회보
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• 제44권1호
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• pp.49.2-49.2
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• 2019

Clusters of galaxies shape up through a series of hierarchical mergers. It is believed that major mergers lead to cluster-wide shock waves, which are manifested as radio relics. The 1RXS J0603.0+4213 and CIZA J2242.8+5301 clusters, for instance, contain Mpc-size giant radio relics in the outskirts. Synchrotron emission from these radio relics reveals the presence of relativistic electrons and the magnetic fields of a few ${\mu}G$ strength. The presence of such magnetic fields in the ICM has been explained by the so-called small-scale turbulent dynamo. To get quantitative measures for magnetic fields in clusters of galaxies, we investigate the development of turbulence and the follow-up amplification of magnetic fields through three-dimensional numerical magnetohydrodynamical (MHD) simulations. The turbulence is induced in highly stratified cluster media, and driven sporadically by major mergers. We here present the results, aiming to answer whether the turbulence dynamo scenario can explain the observed strength and scale of magnetic fields in clusters. Also, we discuss whether the observed properties of giant radio relics can be reproduced in our simulations.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.841-844
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• 2005

Computer vision technology can be used to interpret the images captured by web cameras installed on construction sites to automatically quantify the results. This information can be used for quality control, productivity measurement and to direct construction. Steel frame construction is particularly well suited for automatic monitoring as all structural members can be viewed from a small number of camera locations, and three-dimensional computer models of steel structures are frequently available in a standard electronic format. A system is being developed that interprets the 3-D model and directs a camera to look for individual members as regular intervals to determine when each is in place and report the results. Results from a simple lab-scale system are presented along with preliminary full-scale development.