• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.868-871
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• 2012

반도체와 LCD 산업 분야, 나노급 공정 및 검사 기술이 요구되는 산업 분야의 수요 증가에 따라 초정밀 가공/생산/검사 장비를 설치, 운용하는 FAB. 구조물의 설계 요구가 층증대 되고 있다. 이에 따라 건물의 환경진동 규제치도 강화되고 있는 실정이다. 이와 같은, 대형 구조물에서 서브마이크로 수준의 미진동(微振動)을 제어하는 문제는 여전히 어려운 과제로 남아 있다. 이는 진동 응답을 결정하는 구조와 재료가 복잡하고 다양한 형태를 갖고 있는 반면, 다루어야 할 동적 응답은 극한적으로 작은 마이크로(micro) 이하의 값을 다루어야 한다. 그러므로, 기존에 이용되고 있는 해석과 실험의 결과만으로는 신모델 설계에 적용하는 것은 어렵다. 따라서, 본 논문에서는 이러한 영역의 경험적 데이터물을 체계적인 데이터베이스로 구축하여 새로운 동적 구조 설계 기술의 기반을 제공하고자 한다.

• ETRI Journal
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• v.43 no.2
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• pp.324-331
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• 2021

Space-based automatic dependent surveillance-broadcast (ADS-B) is an important emerging augmentation of existing ground-based ADS-B systems. In this paper, the problem of space-based ultra-long-range reception processing of ADS-B signals is described. We first introduce a header detection method for accurately determining the pulse position of a weak ADS-B signal. We designed a signal encoding method, shaping method, and fitness function. We then employed a genetic algorithm to perform high-precision frequency and phase estimations of the detected weak signal. The advantage of this algorithm is that it can simultaneously estimate the frequency and phase, meaning a direct coherent demodulation can be implemented. To address the computational complexity of the genetic algorithm, we improved the ratio algorithm for frequency estimation and raised the accuracy beyond that of the original ratio algorithm with only a slight increase in the computational complexity using relatively few sampling points.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.130-135
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• 2018

Currently the automobile market is developing eco-friendly vehicles in order to cope with fuel efficiency regulations. Many studies have been conducted to improve travel performance and fuel economy of the environment-friendly vehicles, and vehicle manufacturers study how to manufacture light-weight vehicles for improving fuel economy for both existing vehicles and environment-friendly vehicles. Exemplary light-weight vehicle technologies include optimal design of vehicle body structure which is a light-weight vehicle method by changing component shapes or layout to optimize the vehicle body structure and the new process technology for using new light-weight and very strong materials Various studies.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.850-852
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• 2013

산업발전에 따라 초정밀 가공/생산/검사 장비를 설치, 운용하는 FAB. 구조물의 건축이 증대되고 있으며, 이에 따라 건물의 환경진동 규제치도 강화되고 있는 실정이다. 한국은 일본이나 동남아 국가들과는 달리 지진에 대한 피해가 직접적으로 보고되고 있지는 않지만, 동일본 지진에서와 같이 인접국가의 대규모 지진은 초정밀 장비의 작동에 심각한 영향을 준다. 따라서, 본 논문에서는 대규모 지진에 영향을 받는 일반 건물과 미세한 지반 진동에도 영향을 받는 정밀 FAB. 에서 운용이 가능한 범용적인 지진재해 대비 모니터링 시스템의 설계에 대해 서술한다.

• International Journal of Advanced Culture Technology
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• v.10 no.2
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• pp.292-299
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• 2022

In precision agriculture (PA), the differences of the agriculture related parameters such as temperature, humidity, soil moisture among different fields are considered and analyzed to precisely utilize water, pesticides, fertilizer, seeds, etc. in fields. Hence, it becomes possible to increase the profit, reduce waste and maintain quality products. This paper suggests a framework for RFID sensor network in view of PA, especially, associated with Container-grown seedlings(CGS), and presents the analysis and simulation by using Ultra High Frequency (UHF) RFID tag system. The simulation is divided into the transmitter and receiver part using Matlab/Simulink. The architecture of the model is flexible to achieve different modulation and encoding types. Finally, some results of the simulation are presents.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.18-20
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• 2021

디지털 트윈 기술은 산업 분야와 관련된 방대한 데이터를 다루기 때문에 데이터에서 유의미한 인사이트를 도출하는 것은 매우 중요한 이슈이다. 그러기 위해서는 관리자가 데이터를 직관적이고 빠르게 해석하고 이해할 수 있어야 하며 그와 관련된 표출 기술에 관한 연구가 필요하다. 이에 본 논문은 현장에 대한 정확한 이해를 위해 전 산업 현장에서 공통으로 활용할 수 있도록 데이터를 초정밀로 표출하고 자동으로 디지털 트윈 가상 공간의 데이터 생성 및 저작이 가능한 서비스 플랫폼에 대해 논한다. 첫 번째, 데이터 초정밀 가시화를 위해 실사 영상 기반의 3D 가상 공간 및 현장 오브젝트를 자동으로 생성하여 표출하고, 저작 가능한 기술에 대해 논한다. 두 번째, 생성한 데이터를 서비스 하기 위한 경량화 표출 기술에 대해 논한다. 두 가지 기술 요소의 융합으로 디지털 트윈 가상 공간을 빠르게 생성하여 시간과 비용을 절감할 수 있고, 서비스 가능한 형태로 변환하여 광역 표출 확장성에 대한 효과를 검증하였다.

• Current Optics and Photonics
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• v.8 no.1
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• pp.16-29
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• 2024

This paper presents a comprehensive review of metasurface technology, focusing on its significant role in extraordinary flat optic functionalities. Traditional optical components, though optimized, are bulky and less congruent with modern integrated electromagnetic and photonic systems. Metasurfaces, recognized as the 2D counterparts of bulk metamaterials, offer solutions with their planar, ultra-thin, and lightweight structures. Their meta-atoms are adept at introducing abrupt shifts in optical properties, paving the way for high-precision light manipulation. By introducing the key design principles of these meta-atoms, such as the magnetic dipole and Pancharatnam-Berry phase, various applications in wavefront shaping and beam forming with simple amplitude/phase manipulation and advanced applications including retroreflectors, Janus metasurfaces, multiplexing of optical wavefronts, data encryption, and metasurfaces for quantum applications are reviewed.

• Journal of Korea Port Economic Association
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• v.33 no.3
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• pp.139-154
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• 2017

As competition in domestic and overseas ports intensify, new and small domestic ports are realizing certain limitations to independently secure competitiveness. This study collected data over 60 months with five modifications for container and general cargo volume around Gyeongin Port. Short-period (12 months) cargo volume was forecasted, which revealed the need for a middle-to-long-term development plan. First, the hinterland logistics complex of Gyeongin Port is expected to contribute to the coastal maritime facility through the quasi-public system for fishery product transportation and passenger services. It proposes to achieve this by opening channels to and from China for precision machinery, home network systems, LEDs, and machine industry items. second, specializing the ultra-light cargo transport route, and connecting the coastal island areas of the 5 West Sea Islands to Ara Waterway (Integrated Fishery Product Center of the 5 West Sea Islands). Third, on the basis of organic cooperation of government? local government ? port, the incentive and pre-circular support system would be required, and lastly, it shall carry out the adjustment of functions in nearby ports and specialization strategy simultaneously through the integrated operation of the ports in the capital areas.

• Mass Spectrometry Letters
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• v.7 no.2
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• pp.50-54
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• 2016

Multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) is currently used in our laboratory for isotopic and quantitative analyses of nuclear materials at ultra-trace levels in environmental swipe samples, which is a very useful for monitoring undeclared nuclear activities. In this study, to improve measurement precisions of uranium isotopes at ultratrace levels, we adopted a desolvating nebulizer system (Aridus-II, CETAC., USA), which can improve signal sensitivity and reduce formation of uranium hydride. A peristaltic pump was combined with Aridus-II in the sample introduction system of MC-ICP-MS to reduce long-term signal fluctuations by maintaining a constant flow rate of the sample solution. The signal sensitivity in the presence of Aridus-II was improved more than 10-fold and the formation ratio of UH/U decreased by 16- to 17- fold compared to a normal spray chamber. Long-term signal fluctuations were significantly reduced by using the peristaltic pump. Detailed optimizations and evaluations with uranium standards are also discussed in this paper.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.2
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• pp.183-189
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• 2007

Ultra precise processed parts are required together with the development of optoelectronics industry. As important parts of optoelectronics industry, there are ferrule of optical connector and lens for optical devices. In particular, the lens requires high reliability with high precision without including flaws. These optical modules need ultra precise processing in order to reduce the loss of light sources and various nondestructive inspections are carried out in the finishing stage to separate good and bad quality products. Therefore, it was analyzed through the characteristics of response of amplitude and resonant frequency according to the mass variations of aspheric lens that is used currently in laser printers.