• Title/Summary/Keyword: key point

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Analytical investigation on lateral load responses of self-centering walls with distributed vertical dampers

  • Huang, Xiaogang;Zhou, Zhen;Zhu, Dongping
    • Structural Engineering and Mechanics
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    • 제72권3호
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    • pp.355-366
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    • 2019
  • Self-centering wall (SCW) is a resilient and sustainable structural system which incorporates unbonded posttensioning (PT) tendons to provide self-centering (SC) capacity along with supplementary dissipators to dissipate seismic energy. Hysteretic energy dissipators are usually placed at two sides of SCWs to facilitate ease of postearthquake examination and convenient replacement. To achieve a good prediction for the skeleton curve of the wall, this paper firstly developed an analytical investigation on lateral load responses of self-centering walls with distributed vertical dampers (VD-SCWs) using the concept of elastic theory. A simplified method for the calculation of limit state points is developed and validated by experimental results and can be used in the design of the system. Based on the analytical results, parametric analysis is conducted to investigate the influence of damper and tendon parameters on the performance of VD-SCWs. The results show that the proposed approach has a better prediction accuracy with less computational effects than the Perez method. As compared with previous experimental results, the proposed method achieves up to 60.1% additional accuracy at the effective linear limit (DLL) of SCWs. The base shear at point DLL is increased by 62.5% when the damper force is increased from 0kN to 80kN. The wall stiffness after point ELL is reduced by 69.5% when the tendon stiffness is reduced by 75.0%. The roof deformation at point LLP is reduced by 74.1% when the initial tendon stress is increased from $0.45f_{pu}$ to $0.65f_{pu}$.

Experimental verification and improvement of heat transfer tube local wall temperature measurement method

  • Jiabao Liu;Xiaxin Cao;Peixun Yang
    • Nuclear Engineering and Technology
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    • 제55권12호
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    • pp.4317-4328
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    • 2023
  • To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

Investigation of morphological changes of HPS membrane caused by cecropin B through scanning electron microscopy and atomic force microscopy

  • Hu, Han;Jiang, Changsheng;Zhang, Binzhou;Guo, Nan;Li, Zhonghua;Guo, Xiaozhen;Wang, Yang;Liu, Binlei;He, Qigai
    • Journal of Veterinary Science
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    • 제22권5호
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    • pp.59.1-59.13
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    • 2021
  • Background: Antimicrobial peptides (AMPs) have been identified as promising compounds for consideration as novel antimicrobial agents. Objectives: This study analyzed the efficacy of cecropin B against Haemophilus parasuis isolates through scanning electron microscopy (SEM) and atomic force microscopy (AFM) experiments. Results: Cecropin B exhibited broad inhibition activity against 15 standard Haemophilus parasuis (HPS) strains and 5 of the clinical isolates had minimum inhibition concentrations (MICs) ranging from 2 to 16 ㎍/mL. Microelectrophoresis and hexadecane adsorption assays indicated that the more hydrophobic and the higher the isoelectric point (IEP) of the strain, the more sensitive it was to cecropin B. Through SEM, multiple blisters of various shapes and dents on the cell surface were observed. Protrusions and leakage were detected by AFM. Conclusions: Based on the results, cecropin B could inhibit HPS via a pore-forming mechanism by interacting with the cytoplasmic membrane of bacteria. Moreover, as cecropin B concentration increased, the bacteria membrane was more seriously damaged. Thus, cecropin B could be developed as an effective anti-HPS agent for use in clinical applications.

A Social Motivation-aware Mobility Model for Mobile Opportunistic Networks

  • Liu, Sen;Wang, Xiaoming;Zhang, Lichen;Li, Peng;Lin, Yaguang;Yang, Yunhui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권8호
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    • pp.3568-3584
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    • 2016
  • In mobile opportunistic networks (MONs), human-carried mobile devices such as PDAs and smartphones, with the capability of short range wireless communications, could form various intermittent contacts due to the mobility of humans, and then could use the contact opportunity to communicate with each other. The dynamic changes of the network topology are closely related to the human mobility patterns. In this paper, we propose a social motivation-aware mobility model for MONs, which explains the basic laws of human mobility from the psychological point of view. We analyze and model social motivations of human mobility mainly in terms of expectancy value theory and affiliation motivation. Furthermore, we introduce a new concept of geographic functional cells, which not only incorporates the influence of geographical constraints on human mobility but also simplifies the complicated configuration of simulation areas. Lastly, we validate our model by simulating three real scenarios and comparing it with reality traces and other synthetic traces. The simulation results show that our model has a better match in the performance evaluation when applying social-based forwarding protocols like BUBBULE.

Comparison of Key Words of the Journal of Korean Academy of Fundamentals of Nursing with MeSH (2003-2007) (기본간호학회지 게재 논문의 주요어와 MeSH 용어의 비교(2003-2007년))

  • Chaung, Seung-Kyo;Sohng, Kyeong-Yae;Kim, Kyung-Hee
    • Journal of Korean Academy of Fundamentals of Nursing
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    • 제15권4호
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    • pp.558-565
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    • 2008
  • Purpose: The purpose of this study was to analyze how accurately authors of the Journal of Korean Academy of Fundamentals of Nursing used MeSH terms as key words. Method: A total of 724 key words used in the 225 papers of Journal of Korean Academy of Fundamentals of Nursing from 2003 to 2007 were compared with MeSH terms. Results: Fifty nine point eight percent of total key words were completely coincident with MeSH terms, 13.5% were entry terms, and 21.8% were not MeSH terms. The coincidence rates for 2003 and 2007 separately were 38.5% and 70.9%. Also, 25.3% of papers precisely used MeSH terms as key words and 8% did not use any MeSH terms. Conclusion: The results show that the coincidence rate of key words with MeSH terms was at a moderate level and gradually increased according to year. However, there is a need for us to understand MeSH more specifically and accurately.

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Optical Implementation of Triple DES Algorithm Based on Dual XOR Logic Operations

  • Jeon, Seok Hee;Gil, Sang Keun
    • Journal of the Optical Society of Korea
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    • 제17권5호
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    • pp.362-370
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    • 2013
  • In this paper, we propose a novel optical implementation of a 3DES algorithm based on dual XOR logic operations for a cryptographic system. In the schematic architecture, the optical 3DES system consists of dual XOR logic operations, where XOR logic operation is implemented by using a free-space interconnected optical logic gate method. The main point in the proposed 3DES method is to make a higher secure cryptosystem, which is acquired by encrypting an individual private key separately, and this encrypted private key is used to decrypt the plain text from the cipher text. Schematically, the proposed optical configuration of this cryptosystem can be used for the decryption process as well. The major advantage of this optical method is that vast 2-D data can be processed in parallel very quickly regardless of data size. The proposed scheme can be applied to watermark authentication and can also be applied to the OTP encryption if every different private key is created and used for encryption only once. When a security key has data of $512{\times}256$ pixels in size, our proposed method performs 2,048 DES blocks or 1,024 3DES blocks cipher in this paper. Besides, because the key length is equal to $512{\times}256$ bits, $2^{512{\times}256}$ attempts are required to find the correct key. Numerical simulations show the results to be carried out encryption and decryption successfully with the proposed 3DES algorithm.

Provable Security of Key Derivation Functions Based on the Block Ciphers (블록암호 기반 키유도함수의 증명가능 안전성)

  • Kang, Ju-Sung;Yi, Ok-Yeon;Youm, Ji-Sun
    • Journal of the Korea Institute of Information Security & Cryptology
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    • 제20권4호
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    • pp.3-16
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    • 2010
  • Key derivation functions are used within many cryptographic systems in order to generate various keys from a fixed short key string. In this paper we survey a state-of-the-art in the key derivation functions and wish to examine the soundness of the functions on the view point of provable security. Especially we focus on the key derivation functions using pseudorandom functions which are recommended by NISI recently, and show that the variant of Double-Pipeline Iteration mode using pseudorandom permutations is a pseudorandom function. Block ciphers can be regarded as practical primitives of pseudorandom permutations.

HOPF BIFURCATION IN NUMERICAL APPROXIMATION OF THE SUNFLOWER EQUATION

  • Zhang Chunrui;Zheng Baodong
    • Journal of applied mathematics & informatics
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    • 제22권1_2호
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    • pp.113-124
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    • 2006
  • In this paper we consider the numerical solution of the sunflower equation. We prove that if the sunflower equation has a Hopf bifurcation point at a = ao, then the numerical solution with the Euler-method of the equation has a Hopf bifurcation point at ah = ao + O(h).

CAE Solid Element Mesh Generation from 3D Laser Scanned Surface Point Coordinates

  • Jarng S.S.;Yang H.J.;Lee J.H.
    • Korean Journal of Computational Design and Engineering
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    • 제10권3호
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    • pp.162-167
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    • 2005
  • A 3D solid element mesh generation algorithm was newly developed. 3D surface points of global rectangular coordinates were supplied by a 3D laser scanner. The algorithm is strait forward and simple but it generates hexahedral solid elements. Then, the surface rectangular elements were generated from the solid elements. The key of the algorithm is elimination of unnecessary elements and 3D boundary surface fitting using given 3D surface point data.

A study on the new gamut mapping method for digital soft color proofing (디지털 소프트 칼라 교정인쇄를 위한 새로운 색역 사상방법에 관한 연구)

  • 송경철;강상훈
    • Proceedings of the Korean Printing Society Conference
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    • 한국인쇄학회 2002년도 춘계 학술발표회
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    • pp.10-18
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    • 2002
  • On the process of cross-media color reproduction, a key feature is the use of gamut mapping techniques to adjust the different color gamuts between displays and printers. Even though a number of GMAs have been published, but there are no method satisfactory enough for more exect color reproduction. In this paper, the gamut mapping methods of nearest point clipping(NPC), centroid clipping (SLIN), straight clipping and cusp clipping(CUSP) were tested and analyzed with color difference, and a new gamut mapping algorithm based on variable anchor point method was proposed.

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