• Title/Summary/Keyword: Analysis of key

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Nonlinear Buckling Analysis of H-Type Honeycombed Composite Column with Rectangular Concrete-Filled Steel Tube Flanges

  • Ji, Jing;Xu, Zhichao;Jiang, Liangqin;Yuan, Chaoqing;Zhang, Yunfeng;Zhou, Lijian;Zhang, Shilong
    • International journal of steel structures
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    • v.18 no.4
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    • pp.1153-1166
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    • 2018
  • This paper was concerned with the nonlinear analysis on the overall stability of H-type honeycombed composite column with rectangular concrete-filled steel tube flanges (STHCC). The nonlinear analysis was performed using ABAQUS, a commercially available finite element (FE) program. Nonlinear buckling analysis was carried out by inducing the first buckling mode shape of the hinged column to the model as the initial imperfection with imperfection amplitude value of L/1000 and importing the simplified constitutive model of steel and nonlinear constitutive model of concrete considering hoop effect. Close agreement was shown between the experimental results of 17 concrete-filled steel tube (CFST) specimens and 4 I-beams with top flanges of rectangular concrete-filled steel tube (CFSFB) specimens conducted by former researchers and the predicted results, verifying the correctness of the method of FE analysis. Then, the FE models of 30 STHCC columns were established to investigate the influences of the concrete strength grade, the nominal slenderness ratio, the hoop coefficient and the flange width on the nonlinear stability capacity of SHTCC column. It was found that the hoop coefficient and the nominal slenderness ratio affected the nonlinear stability capacity more significantly. Based on the results of parameter analysis, a formula was proposed to predict the nonlinear stability capacity of STHCC column which laid the foundation of the application of STHCC column in practical engineering.

Selection of key foods for the systematic management of a food and nutrient composition database

  • Shim, Jee-Seon;Lee, Jung-Sug;Kim, Ki Nam;Lee, Hyun Sook;Kim, Hye Young;Chang, Moon-Jeong
    • Nutrition Research and Practice
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    • v.11 no.6
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    • pp.500-506
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    • 2017
  • BACKGROUND/OBJECTIVES: Food composition databases are necessary for assessing dietary intakes. Developing and maintaining a high quality database is difficult because of the high cost of analyzing nutrient profiles and the recent fast-changing food marketplace. Thus, priorities have to be set for developing and updating the database. We aimed to identify key foods in the Korean diet to set priorities for future analysis of foods. SUBJECTS/METHODS: The food consumption data of the Korea National Health and Nutrition Examination Surveys 2013-2014 were used. We modified the US Department of Agriculture's key food approach. First, major foods were analyzed, contributing to 75%, 80%, 85%, or 90% of each nutrient intake. Second, the cumulative contributions to nutrient intakes were compared before and after excluding the foods least commonly consumed by individuals. Third, total nutrient score for each food was calculated by summing all percent contributions times 100 for nutrients. To set priorities among the foods in the list, we sorted the score in descending order and then compared total percent contributions of foods, within the 100, 90, 85, 80, and 75 percentiles of the list. Finally, we selected the minimum list of foods contributing to at least 90% of the key nutrient intake as key items for analysis. RESULTS: Among the 1,575 foods consumed by individuals, 456 were selected as key foods. Those foods were chosen as items above the 80 percentile of the total nutrient score, among the foods contributing at least 85% of any nutrient intake. On an average, the selected key foods contributed to more than 90% of key nutrient intake. CONCLUSIONS: In total, 456 foods, contributing at least 90% of the key nutrient intake, were selected as key foods. This approach to select a minimum list of key foods will be helpful for systematically updating and revising food composition databases.

Analysis of stream cipher system with initial condition and nonlinear function (초기조건과 비선형 함수와의 상관관계를 이용한 스트림 암호시스템 분석)

  • 김지홍;이만영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.2
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    • pp.8-14
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    • 1996
  • Key stream generator consisting of several linear feedback shift registers with a nonlinear combining function have been applied in stream cipher system. Most of the papers until now have been focusing on correlation atack and analysis of key stream generator with nonlinear combining function. Given some part of key stream sequences. We can generate identical output sequences with original key stream sequences if the feedback connection and the maximum order of nonlinear combination function are known.

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CKGS: A Way Of Compressed Key Guessing Space to Reduce Ghost Peaks

  • Li, Di;Li, Lang;Ou, Yu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.3
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    • pp.1047-1062
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    • 2022
  • Differential power analysis (DPA) is disturbed by ghost peaks. There is a phenomenon that the mean absolute difference (MAD) value of the wrong key is higher than the correct key. We propose a compressed key guessing space (CKGS) scheme to solve this problem and analyze the AES algorithm. The DPA based on this scheme is named CKGS-DPA. Unlike traditional DPA, the CKGS-DPA uses two power leakage points for a combined attack. The first power leakage point is used to determine the key candidate interval, and the second is used for the final attack. First, we study the law of MAD values distribution when the attack point is AddRoundKey and explain why this point is not suitable for DPA. According to this law, we modify the selection function to change the distribution of MAD values. Then a key-related value screening algorithm is proposed to obtain key information. Finally, we construct two key candidate intervals of size 16 and reduce the key guessing space of the SubBytes attack from 256 to 32. Simulation experimental results show that CKGS-DPA reduces the power traces demand by 25% compared with DPA. Experiments performed on the ASCAD dataset show that CKGS-DPA reduces the power traces demand by at least 41% compared with DPA.

Research trends in dental hygiene based on topic modeling and semantic network analysis

  • Yun-Jeong Kim;Jae-Hee Roh
    • Journal of Korean society of Dental Hygiene
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    • v.22 no.6
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    • pp.495-502
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    • 2022
  • Objectives: The purpose of this study was to analyze research trends in dental hygiene using topic modeling and semantic network analysis. Methods: A total of 261 published studies were collected 686 key words from the Research Information Sharing Service (RISS) by 2019-2021. Topic modeling and semantic network analysis were performed using Textom. Results: The most frequently and frequency-inverse document frequently key words were 'dental hygienist', 'oral health', 'elderly', 'periodontal disease', 'dental hygiene'. N-gram of key words show that 'dental hygienist-emotional labor', 'dental hygienist-elderly', 'dental hygienist-job performance', 'oral health-quality of life', 'oral health-periodontal disease' etc. were frequently. Key words with high degree centrality were 'dental hygienist (0.317)', 'oral health (0.239)', 'elderly (0.127)', 'job satisfaction (0.057)', 'dental care (0.049)'. Extracted topics were 5 by topic modeling. Conclusions: Results from the current study could be available to know research trends in dental hygiene and it is necessary to improve more detailed and qualitative analysis in follow-up study.

Extention of Kailar Accountability Logic for Symmetric Key Digital Signature and Accountavility Analysis of an Electronic Payment Potocol (대칭키 전자서명을 위한 Kailar 책임 로직 (Accountability Logic)의 확장 및 전자지불 프로토콜의 책임분석)

  • Kim, Yeong-Dal;Han, Seon-Yeong
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.11
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    • pp.3046-3059
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    • 1999
  • Kailar Accountability Logic proposed for the accountability analysis of communication protocols that require accountability and use asymmetric key digital signature is extended for protocols that use symmetric key digital signature. A proposed electronic micropayment protocol that uses symmetric key digital signature is analyzed to illustrate the use of the extend logic in detecting its lack f accountability and suggesting changes to enhance its accountability.

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Biotransformation of natural polyacetylene in red ginseng by Chaetomium globosum

  • Wang, Bang-Yan;Yang, Xue-Qiong;Hu, Ming;Shi, Li-Jiao;Yin, Hai-Yue;Wu, Ya-Mei;Yang, Ya-Bin;Zhou, Hao;Ding, Zhong-Tao
    • Journal of Ginseng Research
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    • v.44 no.6
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    • pp.770-774
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    • 2020
  • Background: Fermentation has been shown to improve the biological properties of plants and herbs. Specifically, fermentation causes decomposition and/or biotransformation of active metabolites into high-value products. Polyacetylenes are a class of polyketides with a pleiotropic profile of bioactivity. Methods: Column chromatography was used to isolate compounds, and extensive NMR experiments were used to determine their structures. The transformation of polyacetylene in red ginseng (RG) and the production of cazaldehyde B induced by the extract of RG were identified by TLC and HPLC analyses. Results: A new metabolite was isolated from RG fermented by Chaetomium globosum, and this new metabolite can be obtained by the biotransformation of polyacetylene in RG. Panaxytriol was found to exhibit the highest antifungal activity against C. globosum compared with other major ingredients in RG. The fungus C. globosum cultured in RG extract can metabolize panaxytriol to Metabolite A to survive, with no antifungal activity against itself. Metabolites A and B showed obvious inhibition against NO production, with ratios of 42.75 ± 1.60 and 63.95 ± 1.45% at 50 µM, respectively. A higher inhibitory rate on NO production was observed for Metabolite B than for a positive drug. Conclusion: Metabolite A is a rare example of natural polyacetylene biotransformation by microbial fermentation. This biotransformation only occurred in fermented RG. The extract of RG also stimulated the production of a new natural product, cazaldehyde B, from C. globosum. The lactone in Metabolite A can decrease the cytotoxicity, which was deemed to be the intrinsic activity of polyacetylene in ginseng.

Security Analysis of Diffie-Hellman based Standard Key Agreement Protocols (이산대수 기반 Diffie-Hellman형 표준 키 분배 프로토콜의 안전성 분석에 관한 연구)

  • Kim, Kyung-Jin;Kim, Sung-Duk;Shim, Kyung-Ah;Won, Dong-Ho
    • The KIPS Transactions:PartC
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    • v.9C no.6
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    • pp.799-808
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    • 2002
  • According to the wide-spread of information transmission system over network, the use of cryptographic system to provide the integrity of transmitted message over network is increasing and the importance of that is emphasized. Because the security of the cryptographic system totally relies on the key, key management is a essential part of cryptographic system. A number of key agreement protocols have been proposed to far, but their rigorous security analysis is still open. In this paper, we analyze the features of Diffie-Hellman based standard key agreement protocols and provide the security analysis of those protocols against several kinds of active attacks.

Sequence Analysis and Molecular Characterization of Wnt4 Gene in Metacestodes of Taenia solium

  • Hou, Junling;Luo, Xuenong;Wang, Shuai;Yin, Cai;Zhang, Shaohua;Zhu, Xueliang;Dou, Yongxi;Cai, Xuepeng
    • Parasites, Hosts and Diseases
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    • v.52 no.2
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    • pp.163-168
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    • 2014
  • Wnt proteins are a family of secreted glycoproteins that are evolutionarily conserved and considered to be involved in extensive developmental processes in metazoan organisms. The characterization of wnt genes may improve understanding the parasite's development. In the present study, a wnt4 gene encoding 491amino acids was amplified from cDNA of metacestodes of Taenia solium using reverse transcription PCR (RT-PCR). Bioinformatics tools were used for sequence analysis. The conserved domain of the wnt gene family was predicted. The expression profile of Wnt4 was investigated using real-time PCR. Wnt4 expression was found to be dramatically increased in scolex evaginated cysticerci when compared to invaginated cysticerci. In situ hybridization showed that wnt4 gene was distributed in the posterior end of the worm along the primary body axis in evaginated cysticerci. These findings indicated that wnt4 may take part in the process of cysticerci evagination and play a role in scolex/bladder development of cysticerci of T. solium.

Efficient Key Detection Method in the Correlation Electromagnetic Analysis Using Peak Selection Algorithm

  • Kang, You-Sung;Choi, Doo-Ho;Chung, Byung-Ho;Cho, Hyun-Sook;Han, Dong-Guk
    • Journal of Communications and Networks
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    • v.11 no.6
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    • pp.556-563
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    • 2009
  • A side channel analysis is a very efficient attack against small devices such as smart cards and wireless sensor nodes. In this paper, we propose an efficient key detection method using a peak selection algorithm in order to find the advanced encryption standard secret key from electromagnetic signals. The proposed method is applied to a correlation electromagnetic analysis (CEMA) attack against a wireless sensor node. Our approach results in increase in the correlation coefficient in comparison with the general CEMA. The experimental results show that the proposed method can efficiently and reliably uncover the entire 128-bit key with a small number of traces, whereas some extant methods can reveal only partial subkeys by using a large number of traces in the same conditions.