• 제목/요약/키워드: cross spectrum

검색결과 367건 처리시간 0.027초

Experimental investigation of characteristics of torsional wind loads on rectangular tall buildings

  • Li, Yi;Zhang, J.W.;Li, Q.S.
    • Structural Engineering and Mechanics
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    • 제49권1호
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    • pp.129-145
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    • 2014
  • In order to investigate the characteristics of torsional wind loads on rectangular tall buildings, five models with different rectangular cross-sections were tested in a boundary wind tunnel. Based on the test results, the RMS force coefficients, power spectrum densities as well as vertical correlation functions of torsional wind loads were analyzed. Formulas that took the side ratio as parameters were proposed to fit the test results above. Comparisons between the results calculated by the formulas and the wind tunnel measurements were made to verify the reliability of the proposed formulas. An simplified expression to evaluate the dynamic torsional wind loads on rectangular tall buildings in urban terrain is presented on basis of the above formulas and has been proved by a practical project. The simplified expressions as well as the proposed formulas can be applied to estimate wind-induce torsional response on rectangular tall buildings in the frequency domain.

유체와 구조물의 연성을 고려한 rack 구조물의 내진해석 (Seismic Analysis of Rack Structure with Fluid-Structure Interaction)

  • 김성종;이영신;류충현;양계형;정성환
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.465-470
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    • 2001
  • In this study, the seismic analysis of rack structure with fluid-structure interaction is performed through use of the Finite Element Method(FEM) code ANSYS. Fluid-structure interaction can specify in terms of an hydrodynamic effect which is defined as the added mass per unit length divided by the area of the cross section. Using the Floor Response Spectrum(FRS) obtained through the time-history analysis, modal analysis and seismic analysis under Operating Basis Earthquake(OBE) and Safe Shutdown Earthquake(SSE) condition is carried out. The fluid-structure interaction effects on the rack structure are investigated.

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Removal of a synthetic broad-spectrum antimicrobial agent, triclosan, in wastewater treatment systems: A short review

  • Lee, Do Gyun
    • Environmental Engineering Research
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    • 제20권2호
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    • pp.111-120
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    • 2015
  • Contaminants of emerging concern (CECs) including endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care product chemicals (PPCPs) have recently received more attention because of their occurrence in water bodies and harmful impacts on human health and aquatic organisms. Triclosan is widely used as a synthetic broad-spectrum antimicrobial agent due to its antimicrobial efficacy. However, triclosan detected in aquatic environment has been recently considered as one of CECs, because of the potential for endocrine disruption, the formation of toxic by-products and the development of cross-resistance to antibiotics in aquatic environment. This comprehensive review focuses on the regulations, toxicology, fate and transport, occurrence and removal efficiency of triclosan. Overall, this review aims to provide better understanding of triclosan and insight into application of biological treatment process as an efficient method for triclosan removal.

Fractional Frequency Reuse (FFR) Usability Improvement in LTE Networks

  • Alotaibi, Sultan
    • International Journal of Computer Science & Network Security
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    • 제22권4호
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    • pp.292-298
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    • 2022
  • Femtocell networks can be a potential method for increasing the capacity of LTE networks, especially in indoor areas. However, unplanned deployment of femtocells results in co-tier interference and cross-tier interference problems. The interference reduces the advantages of implementing femtocell networks to a certain extent. The notion of Fractional Frequency Reuse (FFR) is proposed in order to reduce the impact of interference on the system's performance. In this paper, a dynamic approach for efficiently partitioning the spectrum is suggested. The goal is to enhance the capacity of femtocells, which will improve the performance of the system. The suggested strategy allocates less resources to the macrocell portion of the network, which has a greater number of femtocells deployed to maximize the utilization of available resources for femtocell users. The spectrum division would be dynamic. The proposed strategy is evaluated through a simulation using MATLAB tool. In conclusion, the results showed that the proposed scheme has the potential to boost the system's capacity.

Clustering Red Wines Using a Miniature Spectrometer of Filter-Array with a Cypress RGB Light Source

  • Choi, Kyung-Mee
    • 응용통계연구
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    • 제23권1호
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    • pp.179-187
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    • 2010
  • Miniature spectrometers can be applied for various purposes in wide areas. This paper shows how a wellmade spectrometer on-a-chip of a low performance and low-cost filter-array can be used for recognizing types of red wine. Light spectra are processed through a filter-array of a spectrometer after they have passed through the wine in the cuvettes. Without recovering the original target spectrum, pattern recognition methods are introduced to detect the types of wine. A wavelength cross-correlation turns out to be a good distance metric among spectra because it captures their simultaneous movements and it is affine invariant. Consequently, a well-designed spectrometer is reliability in terms of its repeatability.

Roles of Leptin in Cancer Progression

  • Kang, Yu-Jin;Moon, A-Ree
    • Biomolecules & Therapeutics
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    • 제18권4호
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    • pp.363-374
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    • 2010
  • Growing evidence suggests a prominent role for leptin in human cancer progression. The intricate pattern of leptin cross-talk with other associated signaling pathways is a critical area of research that will ultimately contribute to comprehending the role of leptin in cancer progression. This review summarizes a portion of the current understanding of leptin signaling, with a critical focus on its contribution to tumor cell invasion and metastasis. Five topics are addressed in this review: (1) Leptin receptor, (2) Leptin signaling, (3) Leptin and cancer, and (4) Leptin and tumor invasion. Due to the complex cellular effects of leptin, a more precise understanding of leptin signaling pathways must still be elucidated. Leptin is clearly a major factor for stimulating tumor progression through a complex spectrum of interplay and cross-talk among various signaling molecules. An understanding of the role of leptin in invasion and metastasis will provide valuable information for establishing strategies to modulate leptin signaling, which should be a high priority for the development of anti-cancer therapeutics.

FAST REACTOR PHYSICS AND COMPUTATIONAL METHODS

  • Yang, W.S.
    • Nuclear Engineering and Technology
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    • 제44권2호
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    • pp.177-198
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    • 2012
  • This paper reviews the fast reactor physics and computational methods. The basic reactor physics specific to fast spectrum reactors are briefly reviewed, focused on fissile material breeding and actinide burning. Design implications and reactivity feedback characteristics are compared between breeder and burner reactors. Some discussions are given to the distinct nuclear characteristics of fast reactors that make the assumptions employed in traditional LWR analysis methods not applicable. Reactor physics analysis codes used for the modeling of fast reactor designs in the U.S. are reviewed. This review covers cross-section generation capabilities, whole-core deterministic (diffusion and transport) and Monte Carlo calculation tools, depletion and fuel cycle analysis codes, perturbation theory codes for reactivity coefficient calculation and cross section sensitivity analysis, and uncertainty analysis codes.

Laser CVD SiON막의 막 형성 후 열처리 의존성 (The Effects of Post-annealing on Laser CVD SiON Films)

  • 김창덕;김인수;고중혁;이상권;성영권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.336-338
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    • 1997
  • The anneal behavior of ArF excimer Laser CVD SiON films has been studied using FT-IR absorption spectroscopy. The anneal temperature range was $400{\sim}800^{\circ}C$ Abundant hydrogen effusion from thes layers was observed as anneal temperature increased. The coexistence of both Si-H am N-H bonds offers the possibility for cross linking am evidence for the occurrence of cross lingking was found in the IR spectrum. The electrical properties were also obtained that tire films have low leakage currents am good TZDB properties.

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Research on the Solar Concentrating Optical System for Solar Energy Utilization

  • Duan, Yimeng;Yang, Huajun;Jiang, Ping;Wang, Ping
    • Journal of the Optical Society of Korea
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    • 제17권5호
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    • pp.371-375
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    • 2013
  • To improve the utilization efficiency of solar energy, a new solar optical concentrating system composed of a parabolic reflector with a square cross-section, a hyperbolic reflector with a square cross-section and two converging convex lenses has been designed. The proposed method can simultaneously focus and shape sun light into a square pattern on the solar panel. In addition, the total reflection property of photonic crystal within the range of the visible sunlight spectrum has been analyzed. Finally, the relationship between solar concentrating multiples and the diameter of the primary mirror has been discussed.

Performance Evaluation of the VoIP Services of the Cognitive Radio System, Based on DTMC

  • Habiba, Ummy;Islam, Md. Imdadul;Amin, M.R.
    • Journal of Information Processing Systems
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    • 제10권1호
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    • pp.119-131
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    • 2014
  • In recent literature on traffic scheduling, the combination of the two-dimensional discrete-time Markov chain (DTMC) and the Markov modulated Poisson process (MMPP) is used to analyze the capacity of VoIP traffic in the cognitive radio system. The performance of the cognitive radio system solely depends on the accuracy of spectrum sensing techniques, the minimization of false alarms, and the scheduling of traffic channels. In this paper, we only emphasize the scheduling of traffic channels (i.e., traffic handling techniques for the primary user [PU] and the secondary user [SU]). We consider the following three different traffic models: the cross-layer analytical model, M/G/1(m) traffic, and the IEEE 802.16e/m scheduling approach to evaluate the performance of the VoIP services of the cognitive radio system from the context of blocking probability and throughput.