• Steel and Composite Structures
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• 제37권3호
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• pp.341-351
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• 2020

Steel plate shear wall with self-centering energy dissipation braces (SPSW-SCEDB) is a lateral force-resisting system that exhibits flag-shaped hysteretic responses, which consists of two pre-pressed spring self-centering energy dissipation (PS-SCED) braces and a wall plate connected to horizontal boundary elements only. The present study conducted a series of cyclic tests to study the hysteretic performances of braces in SPSW-SCEDB and the effects of braces on the overall hysteretic characteristics of this system. The SPSW-SCEDB with PS-SCED braces only exhibits excellent self-centering capability and the energy loss caused by the large inclination angle of PS-SCED braces can be compensated by appropriately increasing the friction force. Under the combined effect of the two components, the SPSW-SCEDB exhibits a flag-shaped hysteretic response with large lateral resistance, good energy dissipation and self-centering capabilities. In addition, the wall plate is the primary energy dissipation component and the PS-SCED braces provide supplementary energy dissipation for system. The PS-SCED braces can provide up to 90% self-centering capability for the SPSW-SCEDB system. The compressive bearing capacity of the wall plate should be smaller than the horizontal remaining restoring force of the braces to achieve better self-centering effect of the system.

• 한국컴퓨터정보학회논문지
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• 제8권3호
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• pp.94-99
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• 2003

본 논문에서는 자동 지문 인식 시스템을 구성하기 위하여 MSF에서 위상 신호만으로 상관이 가능한 POC를 기본 시스템으로 하여, 입력 지문 영상에서 위상 신호를 추출하고 기준 지문 영상의 순환 고조파 필터와 2차원 위상 신호 정합을 시키는 방법을 통해 회전 불변 지문 인식 시스템을 구현하였다. 지문 영상은 내부 전반사 모드로 동작하는 프리즘을 통해 얻고, 지문 영상에 대한 2차원 주파수 발생은 광학적으로 수행하고 위상 신호 추출은 디지털 시스템을 이용하는 광-디지털 하이브리드 형태로 광학의 실시간 병렬 처리 특성과 디지털 알고리즘의 유연성 및 정확성을 상호 보완적으로 이용하였다.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1712-1724
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• 2024

Spiral tubes are used in a wide range of applications and it is significant to understand the vibration introduced by two-phase flow in spiral tubes. In this paper, the numerical method is used to study the vibration induced by the gas-liquid two-phase flow in a spiral tube with different flow regimes. The pressure fluctuation characteristics at the pipe wall and the solid vibration response characteristics are obtained. The results show that the motion of small bubbles in bubbly flow leads to small pressure fluctuations with low-frequency broadband (0-50 Hz). The motion of the gas plug in the plug flow causes small amplitude periodic pressure fluctuation with a shortened low-frequency broadband (0-15 Hz) compared to the bubbly flow. The motion of the gas slug in the slug flow causes large periodic fluctuations in pressure with a significant dominant frequency (6-7 Hz). The wavy flow is very stable and has a distinct main frequency (1-2 Hz). The vibration regime in the bubbly flow and wave flow are close to the first-order mode, and the vertical vibrating component is dominant. The plug flow and slug flow excite higher-order vibration modes, and the lateral vibration component plays more important part in the vibration response.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1696-1700
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• 2016

In order to discover plant-derived signaling pathway inhibitors with antifungal properties, a two-component screening system utilizing the calcineurin and Hog1 mitogen-activated protein kinase pathways responsible for the virulence networks of Cryptococcus neoformans was employed, owing to the counter-regulatory actions of these pathways. Of the 1,000 plant extracts tested, two bioactive compounds from Miliusa sinensis were found to act specifically on the calcineurin pathway of C. neoformans. These compounds, identified as pashanone and 5-hydroxy-6,7-dimethoxyflavanone, exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentration values ranging from 4.0 to >128 μg/ml.

• 대한의용생체공학회:의공학회지
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• 제29권6호
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• pp.502-511
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• 2008

This study was designed to develop a new algorithm to extract the voluntary EMG and the evoked EMG from a mixed EMG generated when the muscle is stimulated both voluntarily and by electrical stimulation in the FES system. The proposed parallel filter algorithm consists of three phases: (1) Fourier transform of the mixed EMG, (2) multiplication of the transformed signal to two frequency functions, and (3) inverse Fourier transform. Four incomplete spinal cord injured patients participated in the experiments to evaluate the algorithm by measuring the knee extensor torque and the EMG signals from the quadriceps. Two functions of the algorithms were evaluated: (1) extraction of the evoked EMG and (2) the voluntary EMG from the mixed EMG. The results showed that the algorithm enabled us to separate the two EMG components in real time from the mixed EMG. The algorithm can and will be used for estimating the voluntary torque and the evoked torque independently through an artificial neural network based on the two EMG components, and also for generating a trigger signal to control the on/off time of the FES system.

• 디지털산업정보학회논문지
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• 제8권2호
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• pp.31-40
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• 2012

Face recognition refers to the process of identifying individuals based on their facial features. It has recently become one of the most popular research areas in the fields of computer vision, machine learning, and pattern recognition because it spans numerous consumer applications, such as access control, surveillance, security, credit-card verification, and criminal identification. However, illumination variation on face generally cause performance degradation of face recognition systems under practical environments. Thus, this paper proposes an novel face recognition system using a fusion approach based on local binary pattern and two-dimensional principal component analysis. To minimize illumination effects, the face image undergoes the local binary pattern operation, and the resultant image are divided into two sub-images. Then, two-dimensional principal component analysis algorithm is separately applied to each sub-images. The individual scores obtained from two sub-images are integrated using a weighted-summation rule, and the fused-score is utilized to classify the unknown user. The performance evaluation of the proposed system was performed using the Yale B database and CMU-PIE database, and the proposed method shows the better recognition results in comparison with existing face recognition techniques.

• 산업경영시스템학회지
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• 제27권2호
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• pp.93-101
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• 2004

This paper is intended to assess a dynamic system reliability. Bayesian networks, however, have difficulties in their application for assessing the system reliability especially when the system consists of dependent components and the probability of failure of each component varies over time. Hence, we suggest a method for resolving the difficulties by considering a hoist system composed of two wires. Firstly, we explain the method of calculating the failure probability of the system components. Secondly, we show how to calculate the failure probability of the system for two cases that failure probability of each wire is constant and varying in time, respectively. finally, based on the calculated failure probability of the system, we infer the probability that two interesting events occur.

• International Journal of Reliability and Applications
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• 제2권4호
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• pp.253-262
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• 2001

A k-out-of-n standby system is considered where all of its components are s-independent and classified either working or cold standby connected with imperfect switches. The probability density function of the life length for this system is established in closed form, when the underlying components have constant failure rates. Also the reliability function of the system is derived. Finally, the reliability functions for one, two and three out of four systems are deduced for perfect or imperfect switches and identical or non-identical constant failure rates for working and standby components.

• 산업경영시스템학회지
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• 제38권1호
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• pp.143-151
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• 2015

In this paper, we investigate how the power consumption of a heat pump dryer depends on various factors in the drying process by analyzing variables that affect the power consumption. Since there are in general many variables that affect the power consumption, for a feasible analysis, we utilize the principal component analysis to reduce the number of variables (or dimensionality) to two or three. We find that the first component is correlated positively to the entrance temperature of various devices such as compressor, expander, evaporator, and the second, negatively to condenser. We then model the power consumption as a multiple regression with two and/or three transformed variables of the selected principal components. We find that fitted value from the multiple regression explains 80~90% of the observed value of the power consumption. This results can be applied to a more elaborate control of the power consumption in the heat pump dryer.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.970-973
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• 2003

최근 들어 기업 내 또는 기업간 정보시스템의 개발 패러다임은 2계층 환경에서 3계층 환경으로 이동해오고 있다. 3계층 환경은 시스템의 성능, 확장성, 배포성, 유지보수 등의 측면에서 보다 효율적인 시스템의 구성을 가능하게 한다. 장기간의 설계기간과 대규모의 설계인원을 대상으로 하는 선박의 설계공정관리 시스템은 정보의 실시간성, 정확성이 확보되어야 함에도 불구하고 현재 2계층 환경으로 일부 개발되어 사용되고 있으며, 여전히 미 개발된 업무들도 있는 실정이다. 본 논문에서는 기존의 2차원적 클라이언트/서버 아키텍처 환경에서 3계층 아키텍처인 COM＋ 기반의 환경으로 전환하기 위해 CBD(Component Based Development)기법을 이용한 시스템의 분석 및 설계를 수행하였다. 향후 CBD 기반의 통합 시스템으로 개발함으로써, 선박 설계공정관리 업무의 생산성 및 효율성을 향상시킬 수 있다. 또한, 컴포넌트의 광범위한 재사용을 통해 시스템의 생산성 및 효율성 향상을 기대할 수 있다.