• Title/Summary/Keyword: The First Derivative

Search Result 498, Processing Time 0.027 seconds

Probabilistic Risk Assessment of a Cable-Stayed Bridge Based on the Prediction Method for the Combination of Failure Modes (붕괴모드 조합 예측법에 의한 PSC사장교의 위험도평가)

  • Park, Mi-Yun;Cho, Hyo-Nam;Cho, Taejun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.4A
    • /
    • pp.647-657
    • /
    • 2006
  • Probabilistic Risk Assessment considering statistically random variables is performed for the preliminary design of a Cable Stayed Bridge, which is Prestressed Concrete Bridge consisted of cable and plate girders, based on the method of Working Stress Design and Strength Design. Component reliabilities of cables and girders have been evaluated using the response surface of the design variables at the selected critical sections based on the maximum shear, positive and negative moment locations. Response Surface Method (RSM) is successfully applied for reliability analyses for this relatively small probability of failure of the complex structure, which is hard to obtain through Monte-Carlo Simulations. or through First Order Second Moment Method that can not easily calculate the derivative terms of implicit limit state functions. For the analysis of system reliability, parallel resistance system consisting of cables and plate girder is changed into series connection system and the result of system reliability of total structure is presented. As a system reliability, the upper and lower probabilities of failure for the structural system have been evaluated and compared with the suggested prediction method for the combination of failure modes. The suggested prediction method for the combination of failure modes reveals the unexpected combinations of element failures in significantly reduced time and efforts compared with the previous permutation method or system reliability analysis method, which calculates upper and lower bound failure probabilities.

Thermotropic Behavior of Hydroxypropyl Chitosans Bearing Cholesteryl and Acryloyl Groups (콜레스테릴과 아크릴로일 그룹을 지닌 하이드록시프로필 키토산들의 열방성 거동)

  • 김장훈;정승용;마영대
    • Polymer(Korea)
    • /
    • v.28 no.1
    • /
    • pp.41-50
    • /
    • 2004
  • A new hydroxypropyl chitosan capable of forming a thermotropic liquid crystalline phase and two kinds of derivatives based on the hydroxypropyl chitosan (6-cholesteryloxycarbonylpentoxypropyl) chitosans (CHPCTs) and acrylic acid esters of CHPCT (CHPCTEs) were synthesized. The crosslinked films with liquid crystalline order were also prepared by photocrosslinking CHPCTE in mesophase. The liquid crystalline properties for all the samples and the swelling behavior of the crosslinked samples in acetone were investigated. In contrast with the hydroxypropyl chitosan, all the uncrosslinked cholesteryl-bearing samples farmed monotropic cholesteric phases with left-handed helicoidal structures and exhibited reflection colors over the full cholesteric range. This is the first report of a thermotropic cholesteric liquid crystalline chitosan derivative with reflection bands in the visible region. Both the optical pitches (λ$\_$m/'S) of CHPCT and CHPCTE decrease with temperature or with cholesteryl content at a given temperature. However, the λ$\_$m/ of CHPCT was larger than that of CHPCTE at the same temperature and at the same cholesteryl content. All the crosslinked samples did not display reflection colors, indicating that the cholesteric structure of CHPCTE significantly changes upon crosslinking. The two-dimentional anisotropic swelling characteristic of liquid crystalline networks was observed for all the crosslinked samples.

A Study of the New Chinese Words Under the Influence of Culture Content (문화 콘텐츠 영향의 신조 중국어 고찰)

  • Meng, Xiang-Shan;Lee, Kwang-Ho
    • Journal of Korea Entertainment Industry Association
    • /
    • v.13 no.8
    • /
    • pp.131-142
    • /
    • 2019
  • This paper is intended to examine and analyze the new Chinese words as the result of culture content. The development of the Korean entertainment industry has created a Korean wave around the world. Through this, many Korean words, Internet vocabulary, and cultural concepts have begun to enter China. Among them, there are many new words that have appeared on the Chinese Internet due to the culture content. As the number of Korean fans and Korean learners increases, new words on the Internet are widely used. The new Chinese words, which are influenced by Korean cultural content, are considered an important part of new Chinese vocabulary. To accurately recognize and understand this, first of all six categories of the new Chinese words were analyzed, which were figurative meaning, substitution, loan of foreign words, abbreviation, compound word, derivation. This formulation also works on the Chinese words with the influence of cultural content. There are three types of the Internet new words form Korean cultural. Which were new words in Chinese characters, new words in alphabets, extended meanings. And had analyzed new words through the acquisition of new meanings. Also took specific news titles and songs according to each category. Through new Chinese words, The influence of cultural content had been confirmed. It is expected that these new Chinese words enrich Chinese vocabulary, also help to facilitate communication. And these new Chinese words are often used in public media or in everyday life. We should recognize the existence of these new Chinese words, and have an accurate perception of them.

Inducible Expression of the Lactadherin Gene with a Reverse Tetracycline-Regulated Retroviral Vector System (Tetracycline으로 발현이 유도되는 Retrovirus Vector System을 이용한 Human Lactadherin 유전자의 전이와 발현)

  • 이용석;오훈규;권모선;박창식;김태완;박재복
    • Korean Journal of Animal Reproduction
    • /
    • v.27 no.3
    • /
    • pp.259-268
    • /
    • 2003
  • Lactadherin (formerly known as BA46), a major glycoprotein of the human milk fat globule membrane, is abundant in human breast milk and breast carcinoma cells and is known to prevent symptomatic rotavirus infections. In this study, we tried to transfer the human lactadherin gene to the Chinese Hamster Ovary (CHO) cells using retrovirus vector system and tested inducible expression of the gene under the tetracycline-controllable promoter. At first, tetracycline-mediated inducibility was tested using E.coli LacZ marker gene. NIH3T3 cells co-infected with RevTet-On and RevTRE-LacZ retrovirus vectors showed that the cells responded to doxycycline (a derivative of tetracycline) in a dose-dependent manner, and prominent induction of the lacZ gene expression was observed from 1 $\mu\textrm{g}$/ml of doxycycline concentration. Based on the results of the pilot experiment, inductional expression of the human lactadherin gene was conducted using RevTet-On and RevTRE-Ltd retrovirus vectors. Analysis with the RT-PCR demonstrated successful inductional expression of the lactadherin gene in the Chinese Hamster Ovary (CHO) cells. Considering that constitutive overexpression of the exogenous genes in the target cells causes serious physiological imbalance, the results obtained in this study will be very useful especially in the studies of gene therapy and transgenic animal production.

LasR Might Act as an Intermediate in Overproduction of Phenazines in the Absence of RpoS in Pseudomonas aeruginosa

  • He, Qiuning;Feng, Zhibin;Wang, Yanhua;Wang, Kewen;Zhang, Kailu;Kai, Le;Hao, Xiuying;Yu, Zhifen;Chen, Lijuan;Ge, Yihe
    • Journal of Microbiology and Biotechnology
    • /
    • v.29 no.8
    • /
    • pp.1299-1309
    • /
    • 2019
  • As an opportunistic bacterial pathogen, Pseudomonas aeruginosa PAO1 contains two phenazine-producing gene operons, phzA1B1C1D1E1F1G1 (phz1) and phzA2B2C2D2E2F2G2 (phz2), each of which is independently capable of encoding all enzymes for biosynthesizing phenazines, including phenazine-1-carboxylic acid and its derivatives. Other previous study reported that the RpoS-deficient mutant SS24 overproduced pyocyanin, a derivative of phenazine-1-carboxylic acid. However, it is not known how RpoS mediates the expression of two phz operons and regulates pyocyanin biosynthesis in detail. In this study, with deletion of the rpoS gene in the $PA{\Delta}phz1$ mutant and the $PA{\Delta}phz2$ mutant respectively, we demonstrated that RpoS exerted opposite regulatory roles on the expression of the phz1and phz2 operons. We also confirmed that the phz1 operon played a critical role and especially biosynthesized much more phenazines than the phz2 operon when the rpoS gene was knocked out in P. aeruginosa. By constructing the translational reporter fusion vector lasR'-'lacZ and the chromosomal fusion mutant $PA{\Delta}lasR::lacZ$, we verified that RpoS deficiency caused increased expression of lasR, a transcription regulator gene in a first quorum sensing system (las) that activates overexpression of the phz1 operon, suggesting that in the absence of RpoS, LasR might act as an intermediate in overproduction of phenazine biosynthesis mediated by the phz1 operon in P. aeruginosa.

A Multi-Compartment Secret Sharing Method (다중 컴파트먼트 비밀공유 기법)

  • Cheolhoon Choi;Minsoo Ryu
    • The Transactions of the Korea Information Processing Society
    • /
    • v.13 no.2
    • /
    • pp.34-40
    • /
    • 2024
  • Secret sharing is a cryptographic technique that involves dividing a secret or a piece of sensitive information into multiple shares or parts, which can significantly increase the confidentiality of a secret. There has been a lot of research on secret sharing for different contexts or situations. Tassa's conjunctive secret sharing method employs polynomial derivatives to facilitate hierarchical secret sharing. However, the use of derivatives introduces several limitations in hierarchical secret sharing. Firstly, only a single group of participants can be created at each level due to the shares being generated from a sole derivative. Secondly, the method can only reconstruct a secret through conjunction, thereby restricting the specification of arbitrary secret reconstruction conditions. Thirdly, Birkhoff interpolation is required, adding complexity compared to the more accessible Lagrange interpolation used in polynomial-based secret sharing. This paper introduces the multi-compartment secret sharing method as a generalization of the conjunctive hierarchical secret sharing. Our proposed method first encrypts a secret using external groups' shares and then generates internal shares for each group by embedding the encrypted secret value in a polynomial. While the polynomial can be reconstructed with the internal shares, the polynomial just provides the encrypted secret, requiring external shares for decryption. This approach enables the creation of multiple participant groups at a single level. It supports the implementation of arbitrary secret reconstruction conditions, as well as conjunction. Furthermore, the use of polynomials allows the application of Lagrange interpolation.

Detection of Irradiated Chicken, Pork and Beef by ESR Spectroscopy (닭고기, 돼지고기 및 쇠고기의 방사선 조사 유무 판별을 위한 ESR Spectroscopy의 활용)

  • Yang, Jae-Seung;Kim, Choong-Ki;Lee, Hae-Jung
    • Korean Journal of Food Science and Technology
    • /
    • v.31 no.3
    • /
    • pp.606-611
    • /
    • 1999
  • To identify irradiated foods, studies have been carried out with electron spin resonance (ESR) spectroscopy on bone containing foods, such as chicken, pork, and beef. Bones cleaned, pieced and dried were irradiated with doses of 0, 1, 3, 5 kGys using a $Co^{60}$ irradiator. The bones were placed in a resonant quartz tube with an internal diameter of about 4.0 mm within the Bruker Win-ESR spectrometer, and the intensity of the ESR signal could be quantified by double integration of the first derivative spectrum. The irradiated bone presented an asymmetric absorption in shape, different from that of an unirradiated one. It could be possible to detect at doses lower than 1 kGy below the dose employed commercially (3 kGy) in the case of irradiated chicken bone. The signal intensity was greatest in the beef bone, intermediate in the pork bone and lowest in the chicken bone; it was normally lower for smaller animals than for larger species, and small variations were observed between samples of the same species. The intensity of the signal induced in bones increased linearly with irradiation doses in the range of 1.0 kGy to 5.0 kGy, and it was possible to distinguish between samples given low and high doses of irradiation. The signal stability for 6 weeks made them ideal for the quick and easy identification of irradiated meats.

  • PDF

Risk Assessment for a Steel Arch Bridge System Based upon Response Surface Method Compared with System Reliability (체계신뢰성 평가와 비교한 응답면기법에 의한 강재아치교의 위험성평가)

  • Cho, Tae-Jun
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.20 no.3
    • /
    • pp.273-279
    • /
    • 2007
  • Probabilistic Risk Assessment considering statistically random variables is performed for the preliminary design of an Arch Bridge. Component reliabilities of girders have been evaluated using the response surfaces of the design variables at the selected critical sections based on the maximum shear and negative moment locations. Response Surface Method (RSM) is successfully applied for reliability analyses lot this relatively small probability of failure of the complex structure, which is hard to be calculated by Monte-Carlo Simulations or by First Order Second Moment method that can not easily calculate the derivative terms in implicit limit state functions. For the analysis of system reliability, parallel resistance system composed of girders is modeled as a parallel series connection system. The upper and lower probabilities of failure for the structural system have been evaluated and compared with the suggested prediction method for the combination of failure modes. The suggested prediction method for the combination of failure modes reveals the unexpected combinations of element failures in significantly reduced time and efforts, compared with the previous permutation method or conventional system reliability analysis method.

Inhibition of Barley Acetolactate Synthase by Triazolopyrimidine Derivative (트리아졸로피리미딘계 유도체에 의한 보리 Acetolactate Synthase의 저해)

  • Kim, Sung Ho;NamGoong, Sung Keon;Shin, Jung Hyu;Chang, Soo Ik;Choi, Jung Do
    • Journal of the Korean Chemical Society
    • /
    • v.43 no.4
    • /
    • pp.461-468
    • /
    • 1999
  • Acetolactate synthase (ALS) catalyzes the first common reaction in the biosynthesis of branched-chain amino acids, valine, leucine, and isoleucine. ALS is the common target of several classes of structurally diverse herbicides, the triazolopyrimidines, the imidazolinones, the sulfonylureas, and pyrimidyl-oxy-benzoates. We examined ihibitory activities of newly synthesized triazolopyrimidine sulfonamide derivatives using partially purified ALS from barley. $IC_{50}$ values for the active derivatives are 0.5nM∼8$\mu$M. Among them TP1 and TP2 are the most potent ALS inhibitors with $IC_{50}$ values of 0.5nM and 1.6nM, respectively. These inhibitors are more potent in the inhibition of barley ALS than commercial herbicides, Metosulam ($IC_{50}$;3.6 nM), Flumetsulam ($IC_{50}$;126 nM), and Cadre ($IC_{50};4 {\mu}M$). The progress curves for inhibition of ALS by TP2 showed that the amount of inhibition increases with time. The inhibition of ALS by TP2 was mixed-type inhibition with respect to pyruvate. Dual inhibition analyses of TP2 versus an imidazolinone, Cadre, and Leu showed parallel and intercepting kinetic pattern, respectively. The results suggest that TP2 binds to ALS competively with Cadre but not with Leu. Chemical modification of cysteinly residues in ALS decreased the sensitivity of ALS to Leu, while the modification did not affect the sensitivity of ALS to TP2 and Cadre.

  • PDF

Chemical Characterisation of Organic Functional Group Compositions in PM2.5 Collected at Nine Administrative Provinces in Northern Thailand during the Haze Episode in 2013

  • Pongpiachan, Siwatt;Choochuay, Chomsri;Chonchalar, Jittiphan;Kanchai, Panatda;Phonpiboon, Tidarat;Wongsuesat, Sornsawan;Chomkhae, Kanokwan;Kittikoon, Itthipon;Hiranyatrakul, Phoosak;Cao, Junji;Thamrongthanyawong, Sombat
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.6
    • /
    • pp.3653-3661
    • /
    • 2013
  • Along with rapid economic growth and enhanced agricultural productivity, particulate matter emissions in the northern cities of Thailand have been increasing for the past two decades. This trend is expected to continue in the coming decade. Emissions of particulate matter have brought about a series of public health concerns, particularly chronic respiratory diseases. It is well known that lung cancer incidence among northern Thai women is one of the highest in Asia (an annual age-adjusted incidence rate of 37.4 per 100,000). This fact has aroused serious concern among the public and the government and has drawn much attention and interest from the scientific community. To investigate the potential causes of this relatively high lung cancer incidence, this study employed Fourier transform infrared spectroscopy (FTIR) transmission spectroscopy to identify the chemical composition of the $PM_{2.5}$ collected using Quartz Fibre Filters (QFFs) coupled with MiniVol$^{TM}$ portable air samplers (Airmetrics). $PM_{2.5}$ samples collected in nine administrative provinces in northern Thailand before and after the "Haze Episode" in 2013 were categorised based on three-dimensional plots of a principal component analysis (PCA) with Varimax rotation. In addition, the incremental lifetime exposure to $PM_{2.5}$ of both genders was calculated, and the first derivative of the FTIR spectrum of individual samples is here discussed.