• 조명전기설비학회논문지
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• 제20권9호
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• pp.90-102
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• 2006

In this study, it has been attempted to build up a smart, stable, and integrated Next-generation Home Network (NHN) system capable of supporting more comfortable and convenient life in the future human housing domains, and to find out which institutional tasks are required to activate the related industries. Additionally, this study aims to review a variety of technologies suggested so far in several fields including information and communications, appliance, and building maintenance. This paper analyzes the advantages and disadvantages, acceptance structure and problems of standard technologies and it suggests the political methods and policies to embody them most effectively and integrally in the future. The said certification system is called 'Standardized Certification System for Korean-style Next-generation Home Network Buildings'(abbreviated to K-NHN) as a new system created for the purpose of developing, more effectively, NHN to be introduced in the future.

• Smart Structures and Systems
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• 제11권3호
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• pp.299-314
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• 2013

This paper presents a nonlinear time series analysis technique for evaluating machine defect severity, based on the Recurrence Plot (RP) entropy. The RP entropy is calculated from the probability distribution of the diagonal line length in the recurrence plot, which graphically depicts a system's dynamics and provides a global picture of the autocorrelation in a time series over all available time-scales. Results of experimental studies conducted on a spindle-bearing test bed have demonstrated that, as the working condition of the bearing deteriorates due to the initiation and/or progression of structural damages, the frequency information contained in the vibration signal becomes increasingly complex, leading to the increase of the RP entropy. As a result, RP entropy can serve as an effective indicator for defect severity assessment of rolling bearings.

• Smart Structures and Systems
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• 제22권1호
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• pp.95-103
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• 2018

Active vibration control via inertial mass actuators has been shown as an effective tool to significantly reduce human-induced vertical vibrations, allowing structures to satisfy vibration serviceability limits. However, a lot of practical obstacles have to be solved before experimental implementations. This has motivated simple control techniques, such as direct velocity feedback control (DVFC), which is implemented in practice by integrating the signal of an accelerometer with a band-pass filter working as a lossy integrator. This work provides practical guidelines for the tuning of DVFC considering the damping performance, inertial mass actuator limitations, such as stroke and force saturation, as well as the stability margins of the closed-loop system. Experimental results on a full scale steel-concrete composite structure (behaves similar to a footbridge) with adjustable span are reported to illustrate the main conclusions of this work.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.296-297
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• 2018

최근 들어 작업환경에서 사망사고가 증가하면서 안전 문제는 사회적 중요한 이슈로 등장하였다. 기존의 많은 안전관련 정책 및 제도 등을 통해 안전사고를 줄이는 노력을 하고 있음에도 불구하고 사고 예방에는 한계가 있다. IoT 기술을 활용한 사고예방 서비스들이 최근 상용화되고 있으며 이에 대한 효과도 매우 높은 것으로 나타났다. 본 연구에서는 IoT 기술을 활용하여 작업환경에서 사망사고를 줄일 수 있는 최신 사례들을 살펴보고 IoT 기술이 안전분야에서 나아가야할 방향에 대해 살펴보고자 한다.

• 제어로봇시스템학회논문지
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• 제10권11호
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• pp.971-975
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• 2004

This paper deals with the idea of Electroactive paper (EAPap) actuator and its application possibility. EAPap is a paper that produces large displacement under electrical excitation. EAPap is made with a cellulose paper by constructing thin electrodes on both sides of the paper. When electrical voltage is applied on the electrodes, the EAPap produces bending displacement. EAPap has merits in terms of lightweight, dryness, large displacement output, low actuation voltage and low power consumption. Since the power requirement is so small that it is suitable for microwave-driven smart actuators. This paper describes the working principle and performance of EAPap as an artificial muscle and its possibility far many applications.

• International Journal of Contents
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• 제8권3호
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• pp.20-25
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• 2012

Working in a hazardous environment can decrease work efficiency and cause a variety of occupational diseases. To prevent occupational accidents and build a refreshing and pleasant work environment, therefore, it is necessary to develop an application system through which a worker's safety can be monitored on a realtime basis and provide related services. Recently, smartphones have become very popular across the nation, with over 10 million users. As a result, a variety of application services have been developed and provided in diverse sectors. This study proposes a system structure to develop application services which monitor work environment using smartphones and examines its applicability through the implementation of server and client interfaces.

• Smart Structures and Systems
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• 제4권2호
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• pp.137-152
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• 2008

The work presented in this paper includes material characterisation and an investigation of suitability in seismic dampers for two commercially available NiTi-alloys, along with a numerical analysis of a new damper system employing composite NiTi-wires. Numerical simulations of the new damper system are conducted, using Brinson's one-dimensional constitutive model for shape memory alloys, with emphasis on the system's energy dissipation capabilities. The two alloys tested showed some unwanted residual strain at temperatures higher than $A_f$, possibly due to stress concentrations near inclusions in the material. These findings show that the alloys are not ideal, but may be employed in a seismic damper if precautions are made. The numerical investigations indicate that using composite NiTi-wires in a seismic damper enhances the energy dissipation capabilities for a wider working temperature range.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.219-226
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• 2017

This paper addresses the effective and quantitative image DB construction for the development of front looking camera systems. The automotive industry has expanded the capability of front camera solutions that will help ADAS(Advanced Driver Assistance System) applications targeting Euro NCAP function requirements. These safety functions include AEB(Autonomous Emergency Braking), TSR(Traffic Signal Recognition), LDW(Lane Departure Warning) and FCW(Forward Collision Warning). In order to guarantee real road safety performance, the driving image DB logged under various real road conditions should be used to train core object classifiers and verify the function performance of the camera system. However, the driving image DB would entail an invalid and time consuming task without proper guidelines. The standard working procedures and design factors required for each step to build an effective image DB for reliable automotive front looking camera systems are proposed.

• Journal of Communications and Networks
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• 제9권4호
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• pp.368-376
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• 2007

The large potential bandwidth available in wavelength-division multiplexed optical networks makes this technology of crucial importance for satisfying the ever increasing capacity requirements of the next-generation Internet. In this scenario, the routing and wavelength assignment(RWA) problem that concerns determining the optical paths and wavelengths to be used for connection establishment in a wavelength-routed network, is still one of the most important open issues. In this paper we propose a new online dynamic grooming-capable RWA heuristic scheme working on wavelength division multiplexing(WDM) networks as a multistage selection process. The proposed algorithm is transparent with respect to the presence of wavelength converters, achieves very low connection rejection ratios with minimal computational complexity and is appropriate for the modern multilayer optical circuit and wavelength switched networks with sparse wavelength conversion capability.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.475-477
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• 2017

본 논문에서는 NodeMCU ESP-12E 보드를 사용하여 Wifi 네트워크에서 웹서버로 동작하는 로못 자동차를 구현한 후, 스마트폰과 PC의 웹 브라우저에서 올바로 제어됨을 확인하였다. 연구 결과는 ESP-12E 보드를 사용한 Wifi 가정 자동화에 응용 가능하다.