• Title/Summary/Keyword: FDR

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A Study on the Evaluation of Concrete Unit-Water Content of FDR Sensor Using Deep Learning and Machine Learning (딥러닝과 머신러닝을 이용한 FDR 센서의 콘크리트 단위수량 평가에 관한 연구)

  • Lee, Seung-Yeop;Youn, Ji-Won;Wi, Gwang-Woo;Yang, Hyun-Min;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.29-30
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    • 2022
  • The unit-water content has a very significant effect on the durability of the construction structure and the quality of concrete. Although there are various methods for measuring the unit-water content, there are problems of time required for measurement, precision, and reproducibility. Recently, there is an FDR sensor capable of measuring moisture content in real time through an apparent dielectric constant change of electromagnetic waves. In addition, various artificial intelligence techniques that can non-linearly supplement the accuracy of FDR sensors are being studied. In this study, the accuracy of unit-water content measurement was compared and evaluated using machine learning and deep learning techniques after normalizing the data secured in concrete using frequency domain reflectometry (FDR) sensors used to measure soil moisture at home and abroad. The result of comparing the accuracy of machine learning and deep learning is judged to be excellent in the accuracy of deep learning, which can well express the nonlinear relationship between FDR sensor data and concrete unit-water content.

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Comparisons of Water Behavior and Moisture Content between Rockwools and Coir used in Soilless Culture (무토양재배용 암면과 코이어 배지의 수분 이동 및 함수율 특성 비교)

  • Shin, Jong Hwa;Son, Jung Eek
    • Journal of Bio-Environment Control
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    • v.24 no.1
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    • pp.39-44
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    • 2015
  • To improve crop productivity with optimal water management in soilless culture, the information of physical characteristics of the root medium including water behavior should be required. The objectives of this study were to analyze the physical characteristics including hydraulic properties of the root media commercially used and to analyze the relationships between actual moisture content and measured one by FDR sensor. The weight of the medium was measured by load cell for calculating the actual moisture content. The accuracy of the moisture content measured by FDR sensor was obtained by comparing with the actual one. The water holding capacity of the coir was lower than those of the rockwool due to the features of large and rough particles of the coir. The moisture content measured by FDR sensor showed large difference from the actual moisture contents measured by loadcell, indicating that the calibration of FDR sensor is needed before starting measurement. The optimum range of moisture content for irrigation control was narrow in the coir than the rockwool due to the lower water holding capacity and rehydration capability of the coir. The results of this study can be useful in establishing adequate irrigation strategies in the soilless culture.

Effect of Plant Growth and Production of Tomato on the Water Content Control in Rockwool Culture (암면배지의 수분제어가 토마토의 생육 및 생산성에 미치는 영향)

  • Moon, Doo-Gyung;Kim, So-Hee;Cho, Myeng-Whan;Yu, In-Ho;Ryu, Hee-Ryong;Choi, Kyung-Hee;Kwon, Yong-Hee;Lee, So-Jin
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.2
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    • pp.183-189
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    • 2018
  • This study was carried out to investigate the effect of plant growth and production of tomato (Lycopersicon Esculentum Mill cv. Tefunis) according to the water content of non-recycled rockwool culture in high-rise tomato greenhouse. Daily irrigation amount was 3.8 times higher in the irrigation control by Integrated Solar Radiation (ISR) than in the Frequency Domain Reflectometry (FDR) sensor. Water content of ISR and FDR was 90-95 and 60-65%, respectively. Plant height and weight of tomato fruit was 1.2-1.9 times longer and 1.2-2.0 times heavier in the ISR than in the FDR sensor, respectively. No significantly differed to sugar content of tomato by treatments. Marketable fruits were the higher 1.3 times in the ISR compared with the FDR sensor. Cracking percentage in the ISR was also the higher 2.0 times compared with FDR sensor. Therefore, Irrigation control by ISR was appropriate to improve of plant growth and production of tomato with non-recycled rockwool culture in greenhouse during long-term cultivation.

The Vulnerability Analysis and Modification of SSH Protocol using Casper, FDR (Casper, FDR을 이용한 SSH 프로토콜의 취약성 분석 및 수정)

  • 김일곤;최진영
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 2002.11a
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    • pp.288-291
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    • 2002
  • 보안 프로토콜을 이용하여 사용자 상호 간의 정보의 비밀성, 무결성, 부인방지를 보장하는 일은 반드시 필요한 과제가 되었다. 이에 따라 해당 서비스에 대해 적합한 사용자를 인증하고 인가하기 위해 다양한 보안 프로토콜(EKE, S/KEY, Kerberos등)이 사용되고 있으며, 이와 더불어 보안 프로토콜을 정형적으로 명세하고 검증하기 위한 다양한 방법들이 연구되고 있다. 본 논문에서는 Casper와 FDR을 이용하여 SSH 프로토콜의 취약성을 분석하고, 수정하여 SSH 프로토콜의 안전성을 향상시키고자 하였다.

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Verification of Leader Election Algorithm with CSP/FDR (CSP/FDR을 이용한 리더 선출 알고리즘의 검증)

  • 전철욱;김일곤;안영아;최진영
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04a
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    • pp.25-27
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    • 2004
  • 시스템이 대형화가 되어가고 네트워크 환경이 발전함에 따라 분산 환경이 점점 더 증대되어 가고 있다. 이러한 분산 환경에서 사용되는 리더 선출 알고리즘(Leader Election Algorithm)은 다양하게 제시되었고 본 논문에서는 Garcia-Molina가 제시한 Bully 알고리즘을 프로세스 알제브라 언어인 CSP로 명세하고 FDR 모델체킹 도구를 이용해 해당 요구사항을 만족하는지 검증하였다.

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The Security Analysis of SSH protocol using Casper, FDR (Casper, FDR를 이용한 SSH 프로토콜의 안전성 분석)

  • 김일곤;최진영
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.442-444
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    • 2002
  • 인터넷의 비약적인 발전과 더불어, 인터넷을 활용한 각종 온라인 서비스가 활성화되어 가고 있는 추세이다. 온라인 쇼핑몰, 온라인 뱅킹과 같은 전자 상거래 서비스는 이용자와 서비스 제공자간의 상호 신뢰를 기반으로 동작해야만 하는 서비스이다. 해당 서비스에 대한 적합한 사용자를 인증하고 인가하기 위한 다양한 인증 프로토콜(EKE, S/KEY, Kerberos 등)에 대한 다양한 연구가 진행되어 오고 있다. 본 논문에서는 FDR, Casper과 같은 보안 프로토콜 분석 및 검증 도구를 이용하여 SSH 프로토콜의 위험성을 분석하여 보안 프로토콜의 안전성을 향상시키고자 한다.

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Fuzzy PSO Congestion Management using Sensitivity-Based Optimal Active Power Rescheduling of Generators

  • Venkaiah, Ch;Vinod Kumar, D M
    • Journal of Electrical Engineering and Technology
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    • v.6 no.1
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    • pp.32-41
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    • 2011
  • This paper presents a new method of Fuzzy Particle Swarm Optimization (FPSO)-based Congestion Management (CM) by optimal rescheduling of active powers of generators. In the proposed method, generators are selected based on their sensitivity to the congested line for efficient utilization. The task of optimally rescheduling the active powers of the participating generators to reduce congestion in the transmission line is attempted by FPSO, Fitness Distance Ratio PSO (FDR-PSO), and conventional PSO. The FPSO and FDR-PSO algorithms are tested on the IEEE 30-bus and Practical Indian 75-bus systems, after which the results are compared with conventional PSO to determine the effectiveness of CM. Compared with FDR-PSO and PSO, FPSO can better perform the optimal rescheduling of generators to relieve congestion in the transmission line.

An Experimental Study on the Evaluation of Unit-Water Content Acoording to Concrete Aggregate Variables through FDR Sensor (FDR 센서를 통한 콘크리트 골재 변수에 따른 단위수량 평가에 관한 실험적 연구)

  • Youn, Ji-Won;Yu, Seung-Hwan;Yang, Hyun-Min;Yoon, Jong-Wan;Park, Tae-Joon;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.70-71
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    • 2021
  • The unit quantity that affects the workability, shrinkage cracking, and durability of concrete is an important factor. Methods for measuring the unit quantity include a high frequency heating method, a capacitance method, a unit volume mass method, and a simple method. However, these methods have the disadvantage of poor measurement method, time required, and precision. To solve this problem, a relatively simple and fast measurement method was adopted to compensate for the shortcomings through a Frequency Domain Reflection (FDR) sensor, and the unit quantity was used. In addition, the measurement data was analyzed by deep learning to evaluate the unit quantity of concrete.

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An Experimental Study on the Evaluation of Concrete Unit-Water Content Using High Frequency Moisture Sensor (FDR) (고주파수분센서(FDR)를 활용한 콘크리트 단위수량 평가에 관한 실험적 연구)

  • Lee, Seung-Yeop;Yang, Hyun-Min;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.59-60
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    • 2021
  • The unit-water content has a major problem in concrete structures which leads to micro cracks on the concrete during drying time. Thus, the compressive strength and durability of the concrete structures are significantly reduced. Several techniques have been developed to measure the unit-water content in concrete structures such as heating drying, unit volume mass, and capacitance measurements. However, these techniques have problems in during measurement such as longer time, expensive and difficult in analysis of data. Frequency Domain Reflectivity (FDR) is one of the sensors which used to measure the water content. This method has several advantages including easy to measure, inexpensive, and capable of measuring moisture in real time. In this study, an attempt has been made to evaluate the unit-water content in concrete using the FDR sensor and interpret the data with deep learning method.

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On the Capacity for the Secondary User with Primary Full Duplex Relay Network in Spectrum Sharing Systems (주파수 공유 시스템에서 일차 사용자가 양방향 중계기를 사용할 때의 이차 사용자의 통신 용량 분석)

  • Kim, Hyung-Jong;Hong, Dae-Sik
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.8
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    • pp.39-45
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    • 2012
  • This paper investigates the capacity for the secondary user with the primary full duplex relay (FDR) network in spectrum sharing systems. For sharing the spectrum of the primary user, sharing scheme under the various primary network should be investigated. However, the conventional works only consider the point-to-point primary communication system. When the FDR node is used for the primary networks, both primary relay and destination suffer the interference from the secondary transmitter simultaneously. Thus, the strict interference constraint should be considered to share the spectrum of the primary user. Therefore, we investigate the capacity of the secondary user with the primary FDR network under the average and peak received-power constraints. In addition, we analyze the performance degradation by the selection of the worst interference channels to consider interference constraint in this system. Through the numerical results, the capacities of the primary and secondary users under the average received-power is superior to the that under the peak received-power constraint.