• Title/Summary/Keyword: semi-active system

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3D-QSAR of Angiotensin-Converting Enzyme Inhibitors: Functional Group Interaction Energy Descriptors for Quantitative Structure-Activity Relationships Study of ACE Inhibitors

  • Kim, Sang-Uk;Chi, Myung-Whan;Yoon, Chang-No;Sung, Ha-Chin
    • BMB Reports
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    • v.31 no.5
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    • pp.459-467
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    • 1998
  • A new set of functional group interaction energy descriptors relevant to the ACE (Angiotensin-Converting Enzyme) inhibitory peptide, QSAR (Quantitative Structure Activity Relationships), is presented. The functional group interaction energies approximate the charged interactions and distances between functional groups in molecules. The effective energies of the computationally derived geometries are useful parameters for deriving 3D-QSAR models, especially in the absence of experimentally known active site conformation. ACE is a regulatory zinc protease in the renin-angiotensin system. Therapeutic inhibition of this enzyme has proven to be a very effective treatment for the management of hypertension. The non bond interaction energy values among functional groups of six-feature of ACE inhibitory peptides were used as descriptor terms and analyzed for multivariate correlation with ACE inhibition activity. The functional group interaction energy descriptors used in the regression analysis were obtained by a series of inhibitor structures derived from molecular mechanics and semi-empirical calculations. The descriptors calculated using electrostatic and steric fields from the precisely defined functional group were sufficient to explain the biological activity of inhibitor. Application of the descriptors to the inhibition of ACE indicates that the derived QSAR has good predicting ability and provides insight into the mechanism of enzyme inhibition. The method, functional group interaction energy analysis, is expected to be applicable to predict enzyme inhibitory activity of the rationally designed inhibitors.

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Pharmaceutical Formulation and Evaluation of Sustained - Release Hydrophilic Matrix Tablet of Cefatrizine Propyleneglycol Using Polyethylene Oxide (폴리에틸렌옥사이드를 이용한 세파트리진프로필렌글리콜 서방성매트릭스 정제의 제조 및 평가)

  • Lee, Eon-Hyoung;Park, Sun-Young;Jee, Ung-Kil;Kim, Dong-Chool
    • Journal of Pharmaceutical Investigation
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    • v.31 no.1
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    • pp.37-41
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    • 2001
  • Various characteristics of polyethylene oxide (PEO) are useful for drug delivery systems. In this study, PEO was used as a sustained release matrix system containing cefatrizine propyleneglycol (Cefa-PG) which is a new semi-synthetic broad-spectrum and orally active cephalosporin. Five kinds of sustained release matrix tablets were formulated with various content of PEO and other ingredients. And three types of matrix tablets were formulated of which compositions were the same but the hardness was different. It was found that PEO content influenced drug release rate. Increasing PEO content, the drug release rate from matrix tablets was decreased. In addition, Avicel, one of the ingredients of matrix components, changed the drug release from the sustained release PEO matrix tablets. With increasing Avicel content, the rate of drug release was increased. For the effect of hardness of matrix tablets, the rate of drug release is decreased with increasing hardness. In comparison of bioavailability parameters after oral administration of Cefa-PG PEO matrix tablets and general Cefa-PG capsule in beagle dog, the sustained release PEO matrix tablets is more useful than a general dosage form. $AUC^{0-12}$ of the sustained release PEO matrix tablet and the general dosage form was 1.16 and 0.644 respectively.

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A Study on the Role of Costumes in Conceptual Art (개념미술에서 의상의 역할)

  • Cho, Jung-Mee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.7
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    • pp.828-840
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    • 2011
  • Fine art and clothes have been closely connected since art became part of civilization. However, there relationship was one-sided rather than exchanging the essence of each other. In the $20^{th}$ century, modern art began to change. Artists started intervening clothes in their work as conceptual tools. In the 1960s, Marcel Duchamp started to study 'what is fine art?' He tried to perform anti-aesthetic work that denies traditional types and contents of fine art by reconsidering a concept of fine art that started a new chapter of conceptual art in the late $20^{th}$ century. Conceptual art is about concepts and ideas of the work rather than aesthetic and material concerns for the challenges traditional ideas. Conceptual art asks audiences for more active reactions. For these reasons, semi logical ideas and clothes became very important to conceptual art. This study categorizes and analyzes various roles of clothes in conceptual art. Conceptual arts since 1960 were studied in this research and the works of clothes were intervened were analyzed. The types of using clothes in conceptual art can be divided into 'ready made,' 'intervention,' 'data type,' 'language,' and 'action and process.' The different types were mixed together rather than used alone. Conceptual artists tried to deliver the characteristics and attributions of modern society through clothes. They expressed criticism of political society, anti war movements, absence caused by death, new lives, violated femininity, changed meanings of marriage, and absence of individual rights under the social system in their work. Clothes played their roles as concepts of various things including violated femininity, illusions of politicians, autocracy, new lives, social systems, and regulations.

Control of wind-induced motion in high-rise buildings with hybrid TM/MR dampers

  • Aly, Aly Mousaad
    • Wind and Structures
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    • v.21 no.5
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    • pp.565-595
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    • 2015
  • In recent years, high-rise buildings received a renewed interest as a means by which technical and economic advantages can be achieved, especially in areas of high population density. Taller and taller buildings are being built worldwide. These types of buildings present an asset and typically are built not to fail under wind loadings. The increase in a building's height results in increased flexibility, which can lead to significant vibrations, especially at top floors. Such oscillations can magnify the overall loads and can be annoying to the top floors' occupants. This paper shows that increased stiffness in high-rise buildings may not be a feasible solution and may not be used for the design for comfort and serviceability. High-rise buildings are unique, and a vibration control system for a certain building may not be suitable for another. Even for the same building, its behavior in the two lateral directions can be different. For this reason, the current study addresses the application of hybrid tuned mass and magneto-rheological (TM/MR) dampers that can work for such types of buildings. The proposed control scheme shows its effectiveness in reducing floors' accelerations for both comfort and serviceability concerns. Also, a dissipative analysis carried out shows that the MR dampers are working within the possible range of optimum performance. In addition, the design loads are dramatically reduced, creating more resilient and sustainable buildings. The purpose of this paper is to stimulate, shape, and communicate ideas for emerging control technologies that are essential for solving wind related problems in high-rise buildings, with the objective to build the more resilient and sustainable infrastructure and to optimally retrofit existing structures.

Early adjusting damping force for sloped rolling-type seismic isolators based on earthquake early warning information

  • Hsu, Ting-Yu;Huang, Chih-Hua;Wang, Shiang-Jung
    • Earthquakes and Structures
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    • v.20 no.1
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    • pp.39-53
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    • 2021
  • By means of installing sloped rolling-type seismic isolators (SRI), the horizontal acceleration transmitted to the to-be-protected object above can be effectively and significantly reduced under external disturbance. To prevent the maximum horizontal displacement response of SRI from reaching a threshold, designing large and conservative damping force for SRI might be required, which will also enlarge the transmitted acceleration response. In a word, when adopting seismic isolation, minimizing acceleration or displacement responses is always a trade-off. Therefore, this paper proposes that by exploiting the possible information provided by an earthquake early warning system, the damping force applied to SRI which can better control both acceleration and displacement responses might be determined in advance and accordingly adjusted in a semi-active control manner. By using a large number of ground motion records with peak ground acceleration not less than 80 gal, the numerical results present that the maximum horizontal displacement response of SRI is highly correlated with and proportional to some important parameters of input excitations, the velocity pulse energy rate and peak velocity in particular. A control law employing the basic form of hyperbolic tangent function and two objective functions are considered in this study for conceptually developing suitable control algorithms. Compared with the numerical results of simply designing a constant, large damping factor to prevent SRI from pounding, adopting the recommended control algorithms can have more than 60% reduction of acceleration responses in average under the excitations. More importantly, it is effective in reducing acceleration responses under approximately 98% of the excitations.

A Study on Fashion Color Preferences According to the Fashion Interest and Lifestyle of the New Silver Generation (뉴 실버 세대의 패션관심도와 라이프스타일에 따른 패션 색채 선호도 연구)

  • Lee, Semi;Koo, Sumin
    • Journal of Fashion Business
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    • v.25 no.5
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    • pp.38-56
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    • 2021
  • The New Silver Generation, which includes retired baby boomers, is eschewing traditional lifestyles, remaining socially and economically active, and striving to enjoy their lives. It is necessary to understand the preferences, sensibilities, and fashion propensities of such individuals. Thus, this study analyzed the New Silver Generation's fashion color preferences and proposed fashion color scheme guidelines that could be used in the fashion industry. First, surveys were conducted in people of the New Silver Generation aged from 55 to 65 years. The survey questions included the following: fashion color preferences, fashion sensibility and taste preferences, fashion interests, lifestyle, and demographic background. Second, the survey was conducted to identify differences in color preferences based on respondents' fashion interests and lifestyles. Next, to compose color palettes for the survey, 45 colors from the Munsell color system were chosen at random. The major research results were as follows: It was shown that socializing- and health-preferring individuals wore achromatic color, leisure-preferring individuals wore P color, and self-preferring individuals wore B color. The commonly worn colors were achromatic colors. After the age of 55 years, health- and leisure-preferring individuals often wore R color and RP color, respectively. Thus, this study proposed a color scheme arrangement that used achromatic colors, such as black and white, as the main colors list for the four lifestyle types.

Optimal design of nonlinear damping system for seismically-excited adjacent structures using multi-objective genetic algorithm integrated with stochastic linearization method (추계학적 선형화 방법 및 다목적 유전자 알고리즘을 이용한 지진하중을 받는 인접 구조물에 대한 비선형 감쇠시스템의 최적 설계)

  • Ok, Seung-Yong;Song, Jun-Ho;Koh, Hyun-Moo;Park, Kwan-Soon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.6
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    • pp.1-14
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    • 2007
  • Optimal design method of nonlinear damping system for seismic response control of adjacent structures is studied in this paper. The objective functions of the optimal design are defined by structural response and total amount of the dampers. In order to obtain a solution minimizing two mutually conflicting objective functions simultaneously, multi-objective optimization technique based on genetic algorithm is adopted. In addition, stochastic linearization method is embedded into the multi-objective framework to efficiently estimate the seismic responses of the adjacent structures interconnected by nonlinear hysteretic dampers without performing nonlinear time-history analyses. As a numerical example to demonstrate the effectiveness of the proposed technique, 20-story and 10-story buildings are considered and MR dampers of which hysteretic behaviors vary with the magnitude of the input voltage are considered as nonlinear hysteretic damper interconnecting two adjacent buildings. The proposed approach can provide the optimal number and capacities of the MR dampers, which turned out to be more economical than the uniform distribution system while maintaining similar control performance. The proposed damper system is verified to show more stable performance in terms of the pounding probability between two adjacent buildings. The applicability of the proposed method to the design problem for optimally placing semi-active control system is examined as well.

Fuzzy Control of Smart Base Isolation System using Genetic Algorithm (유전자알고리즘을 이용한 스마트 면진시스템의 퍼지제어)

  • Kim, Hyun-Su;Roschke, P.N.
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.2 s.42
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    • pp.37-46
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    • 2005
  • To date, many viable smart base isolation systems have been proposed and investigated. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively, of the smart base isolation system. A fuzzy logic controller (FLC) is used to modulate the MR damper because the FLC has an inherent robustness and ability to handle non linearities and uncertainties. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. This method is efficient in improving local portions of chromosomes. Neuro fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find optimal fuzzy rules and the GA optimized FLC outperforms not only a passive control strategy but also a human designed FLC and a conventional semi active control algorithm.

Validity of Linear Combination Approach based on Net Damping Analysis of Cable-Damper System (케이블-댐퍼 시스템의 전체감쇠비 해석을 통한 선형조합 접근법의 유효성)

  • Kim, Hyeon Kyeom;Hwang, Jae Woong;Lee, Myeong Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.467-475
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    • 2009
  • Existing studies have suggested Universal Curve only for supplemental damping by damper. Therefore net damping has been determined by means of arithmetic summation between intrinsic, aero-damping of cable and supplemental damping of damper. However linear combination approach by means of the arithmetic summation is not enough theoretical background. So validity of this approach should be verified in order to design adequate cable-damper system by engineers. This study establishes governing differential equation which can consider intrinsic, aero-damping and supplemental damping as well. And also analysis method is solved by combination of muller method and successive iteration method. Consequently, this study succeeds in verification for validity of linear combination approach. As a result of this study, linear combination approach is limitedly effective in case of low stiffness and optimum damping coefficient of damper, short distance from support to damper, lower vibration mode, low aero-damping, and normal windy environment. Whereas this study will be effective in case of opposite conditions, and existing studies or linear combination approach occur to further error. Meaning of this study presents exact solution for net damping of cable-damper system, and verifies linear combination approach by means of the analysis method. In the future, if monitoring of optimum damping coefficient of a damper against aero-damping is feasible on time, algorithm of this study will be available for control of cable and semi-active damper system such as magneto-rheological damper.

Technology Development for Non-Contact Interface of Multi-Region Classifier based on Context-Aware (상황 인식 기반 다중 영역 분류기 비접촉 인터페이스기술 개발)

  • Jin, Songguo;Rhee, Phill-Kyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.6
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    • pp.175-182
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    • 2020
  • The non-contact eye tracking is a nonintrusive human-computer interface providing hands-free communications for people with severe disabilities. Recently. it is expected to do an important role in non-contact systems due to the recent coronavirus COVID-19, etc. This paper proposes a novel approach for an eye mouse using an eye tracking method based on a context-aware based AdaBoost multi-region classifier and ASSL algorithm. The conventional AdaBoost algorithm, however, cannot provide sufficiently reliable performance in face tracking for eye cursor pointing estimation, because it cannot take advantage of the spatial context relations among facial features. Therefore, we propose the eye-region context based AdaBoost multiple classifier for the efficient non-contact gaze tracking and mouse implementation. The proposed method detects, tracks, and aggregates various eye features to evaluate the gaze and adjusts active and semi-supervised learning based on the on-screen cursor. The proposed system has been successfully employed in eye location, and it can also be used to detect and track eye features. This system controls the computer cursor along the user's gaze and it was postprocessing by applying Gaussian modeling to prevent shaking during the real-time tracking using Kalman filter. In this system, target objects were randomly generated and the eye tracking performance was analyzed according to the Fits law in real time. It is expected that the utilization of non-contact interfaces.