• 전자공학회논문지
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• 제50권9호
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• pp.144-155
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• 2013

본 논문에서는 안드로이드 앱과 TI 320F28335 MCU를 활용한 마이크로그리드용 저가형 원격 전원품질이상 감시 시스템(Remote Power-quality-failure Monitoring System : RPMS)을 제안한다. 설계한 RPMS 테스트 베드는 스마트 노드와 서버 그리고 안드로이드 앱으로 구성된다. 특별히 RPMS 스마트 노드는 기존 감시 시스템과는 달리 C2000 계열 MCU를 이용한 저가형으로 설계되며 전력신호처리를 위한 신호처리 기능과 함께 전원품질 모니터링 정보 전송을 위한 데이터 전송 기능을 포함한다. 전력신호처리 기능은 순시전압강하, 순시전압상승 혹은 순시정전에 대한 웨이브렛 기반 검출 알고리즘과 고조파에 대한 FFT 기반 검출 알고리즘을 구현하며, 이를 이용 신뢰성 있는 실시간 전원품질 감시를 가능하게 한다. 데이터 전송 기능은 전원품질 원격 감시를 위한 저 복잡도의 전용 전송 프로토콜 알고리즘을 구현하며, 품질이상 검출 메시지 전송을 위한 간단한 데이터 포맷 (msg_Diag)을 정의 사용한다. 스마트 노드 측정 결과는 서버는 물론 WiFi (혹은 WAN) 망에 연동되는 안드로이드 폰으로 전송되어 실시간 원격 모니터링을 가능하게 한다. RPMS 테스트 베드의 서버와 노드 간 통신에는 RS-232 혹은 블루투스의 유 무선통신을 이용하며, 노드에 구현된 전원품질이상 검출 알고리즘은 CCS (Code Composer Studio) 3.3 환경하에 C 언어로 구현한다.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1954-1961
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• 2011

주거지에서의 지속가능성은 어메니티, 거주성, 건강 등의 주제와 밀접한 관련이 있으며, 지속가능성의 개념은 도시성장관리, 도시재생, 뉴 어바니즘, 압축개발, 스마트성장, 질좋은 주거환경의 개념과 상통하는 개념으로 사용되고 있다. 거주성능관리시스템(RPMS)은 다양한 도시성능을 판단하고 평가할 수 있는 시스템으로, 도시관련 계획가나 관리자의 측면에서도 활용할 수 있다. 본 연구는 서울시정개발연구원에서 개발한 거주환경의 질 지표를 주거지의 지속가능성 지표로하여 RPMS를 이용한 평가가능성을 과 적용방안을 모형으로 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4123-4144
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• 2016

Vehicular Ad Hoc Networks (VANETs) utilize radio propagation models (RPMs) to predict path loss in vehicular environment. Modern urban vehicular environment contains road infrastructure units that include road tunnels, straight roads, curved roads flyovers and underpasses. Different RPMs were proposed in the past to predict path loss, but modern road infrastructure units especially flyovers and underpasses are neglected previously. Most of the existing RPMs are computationally complex and ignore some of the critical features such as impact of infrastructure units on the signal propagation and the effect of both static and moving radio obstacles on signal attenuation. Therefore, the existing RPMs are incapable of predicting path loss in flyovers and underpass accurately. This paper proposes an RPM to predict path loss for vehicular communication on flyovers and inside underpasses that considers both the static and moving radio obstacles while requiring only marginal overhead. The proposed RPM is validated based upon the field measurements in 5 GHz frequency band. A close agreement is found between the measured and predicted values of path loss.

• Nuclear Engineering and Technology
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• 제52권3호
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• pp.626-632
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• 2020

Radiation Portal Monitors (RPMs) are our primary border defense against nuclear smuggling, but are they still the best way to spend limited funds? The purpose of this research is to strategically compare RPM defense at the border with state-side mobile detectors. Limiting the problem to a comparison of two technologies, a decision-maker can prioritize how to best allocate resources, by reinforcing the border with stationary overt RPMs, or by investing in Mobile Radiation Detection Systems (MRDs) which are harder for an adversary to detect but may have other weaknesses. An abstract, symmetric network was studied to understand the impact of initial conditions on a network. An asymmetric network, loosely modeled on a state transportation system, is then examined for the technology that will maximally suppress the adversary's success rate. We conclude that MRDs, which have the advantage of discrete operation, outperform RPMs deployed to a border. We also conclude that MRDs maintain this strategic advantage if they operate with one-tenth the relative efficiency of their stationary counter-parts or better.

• 한국CDE학회논문집
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• 제15권1호
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• pp.51-59
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• 2010

People evaluate urban residential regions quite frequently and sensitively, considering issues such as locations or ease of use of in-site facilities or nearby urban facilities, and those results are bound to be reflected to real estate costs quite immediately. However, there have been frequently recurring questions regarding objectivity of evaluations in terms of results and methods reflected on indexes such as land costs for various reasons. RPMS -Residence Performance Management System- which targets currently in most cases on urban residential areas, suggests instrumental methodology of objective approach toward sensitive urban residence performance evaluation. This paper explains and suggests instrumental utilization of RPMS and its implementations, evaluation methodology and quantitative way of evaluation. In terms of implementation we explain issues such as adding target locations into new residence planning sites, quantification of properties on evaluation indexes of residential performance and/or habitability in terms of checklists, formulas for evaluation, delicate adjustment of evaluation results by setting weights on evaluation indexes, as well as reports on results. Research on appropriate weights and weight settings regarding evaluation indexes, however, exceeds the range of this paper so that this paper focuses on explaining residence performance evaluation and management methodology.

• Journal of the Optical Society of Korea
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• 제20권3호
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• pp.341-357
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• 2016

A novel asymmetric multiple-image encryption method using an octonion Fresnel transform (OFST) and a two-dimensional Sine Logistic modulation map (2D-SLMM) is presented. First, a new multiple-image information processing tool termed the octonion Fresneltransform is proposed, and then an efficient method to calculate the OFST of an octonion matrix is developed. Subsequently this tool is applied to process multiple plaintext images, which are represented by octonion algebra, holistically in a vector manner. The complex amplitude, formed from the components of the OFST-transformed original images and modulated by a random phase mask (RPM), is used to derive the ciphertext image by employing an amplitude- and phase-truncation approach in the Fresnel domain. To avoid sending whole RPMs to the receiver side for decryption, a random phase mask generation method based on SLMM, in which only the initial parameters of the chaotic function are needed to generate the RPMs, is designed. To enhance security, the ciphertext and two decryption keys produced in the encryption procedure are permuted by the proposed SLMM-based scrambling method. Numerical simulations have been carried out to demonstrate the proposed scheme's validity, high security, and high resistance to various attacks.

• 대한의용생체공학회:의공학회지
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• 제18권4호
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• pp.381-388
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• 1997

본 논문은 환자 모니터링 시스템에서 환자 모니터, 중앙 환자 모니터, DB서버 그리고 임상 의사용 워커스테이션을 연결하기 위한 인터베드 통신망의 통신방식의 설계와 구현에 대해 기술하였다. 실시간 생체신호 모니터링을 위해 필요한 조건들을 바탕으로 각종 메시지 형식과 교환방식을 결정하였으며, 객체지향 설계기법을 적용하여 구현하였다. 현재, 인터베드 통신방식을 사용하여 구현된 서비스는 모니터링 중인 환자들에 대한 정보를 제공하기 위한 환자 위치 결정 서비스와 실시간으로 환자의 생체 신호 정보를 전달하기 위한 원격 환자 모니터링 서비스이다. 임상 현장에서 실험한 결과 이들 서비스들이 실시간 생체신호 모니터링에 필요한 조건들을 모두 만족하고 있음을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1006-1011
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• 1991

In this paper, a neural network estimator which estimates the output of the wide range oxygen sensor is proposed, The neural network estimator is constructed to give the output of the wide range oxygen sensor from rpm, fuel injection time, throttle position, and output voltage of the exhaust gas oxygen sensor. And, using this estimator, PI controller for air-fuel ratio control is designed. Experiment results show that the proposed method gives good results for SONATA engine under light load and constant rpms.

• International Journal of Aeronautical and Space Sciences
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• 제16권4호
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• pp.500-509
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• 2015

The numerical simulation of two-dimensional moving blade row interactions is conducted by CFD means to investigate the interactions between the front and rear propeller in a stratospheric airship contra-rotating open propeller configuration caused by different rotational speeds. The rotational speed is a main factor to affect the propeller Reynolds number which impact the aerodynamic performance of blade rows significantly. This effect works until the Reynolds number reaches a high enough value beyond which the coefficients become independent. Additionally, the interference on the blade row has been revealed by the investigation. The front blade row moves in the induced-velocity field generated by the rear blade row and the aerodynamic coefficients are influenced when the rear blade row has fast RPMs. The rear blade row moving behind the front one is affected directly by the wake and eddies generated by the front blade row. The aerodynamic coefficients reduce when the front blade row has slow RPMs while increase when the front blade row moves faster than itself. But overall, the interference on the front blade row due to the rear blade row is slight and the interference on the rear blade row due to the front blade row is much more significant.

• 한국해양공학회지
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• 제25권4호
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• pp.23-27
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• 2011

This experimental study was performed to find rpms of the impeller and the surface flow accelerator to make a uniform velocity vertical distribution in the circular water channel. PIV technique was employed to measure the water velocity profiles into the water depth from the free surface. The number of instantaneous velocity profiles was decomposed into mean and turbulence velocity components, and the distribution of velocity fluctuation and turbulence intensity were computed for each experimental condition. From these results, the velocity uniformity was quantitatively determined to present the flow quality in the measuring section of the circular water channel. It has been shown that the proper operation of the surface flow accelerator would make the uniform velocity profiles and reduce the velocity fluctuation near the free surface.