• Title/Summary/Keyword: new approaches

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An Introduction to Systems Theory Approach to Accident Modeling AND Its Applications (시스템이론 기반의 안전사고 모델의 해석과 응용사례 소개)

  • Park, Cheol-Ho;Park, Yeong-Won
    • 시스템엔지니어링워크숍
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    • s.4
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    • pp.151-154
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    • 2004
  • This paper presents the general system theory and its applications to the safety analysis method that is a recent trend over the traditional event-driven model. This new model is known as STAMP(Systems Theory Accident Modeling and Process)proposed by Nancy G. Leveson in MIT. The new model has benefits of systemic approaches concerning the system safety as a whole including the context it is in, its stimulants and outcomes, and its parts as well as the relationships among them in a holistic manner. The method consists of a hierarchical control structure, a process model, and the safety constraints governing the control. This paper demonstrates an example the contrasts the differences between the approaches of STAMP and the traditional safety models.

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Optimal Control for Discrete-Time Takagi-Sugeno Fuzzy Systems Based on Relaxed Non-Quadratic Stabilization Conditions (완화된 Non-Quadratic 안정화 조건을 기반으로 한 이산 시간 Takagi-Sugeno 퍼지 시스템의 최적 제어)

  • Lee, Dong-Hwan;Park, Jin-Bae;Yang, Han-Jin;Joo, Young-Hoon
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1724_1725
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    • 2009
  • In this paper, new approaches to optimal controller design for a class of discrete-time Takagi-Sugeno (T-S) fuzzy systems are proposed based on a relaxed approach, in which non-quadratic Lyapunov function and non-parallel distributed compensation (PDC) control law are used. New relaxed conditions and linear matrix inequality (LMI) based design methods are proposed that allow outperforming previous results found in the literature. Finally, an example is given to demonstrate the efficiency of the proposed approaches.

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Friction Model to Realize Self-Excited Vibration of Multi-body Systems (다물체계의 자려진동 구현을 위한 마찰 모델링)

  • Roh, Hyun-Young;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.103-108
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    • 2007
  • This paper presents a friction model to realize self-excited vibration of multi-body systems. The friction coefficient is modeled with a spline function in most commercial codes. Even if such a function resolves the problem of discontinuity in friction force, it cannot realize self-excited vibration phenomena. Furthermore, as the relative velocity approaches zero, the friction coefficient approaches zero with the conventional model. So, slip occurs when small force is applied to the system. To avoid these problems a new friction model is proposed in this study. With the new friction model, the self-excited vibration can be realized since the friction coefficient changes with the relative velocity. Furthermore, the slip phenomena could be reduced significantly with the proposed model.

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Review of Desulfurization Technology for Ultra Low Sulfur Diesel Production (초저황 디젤 생산을 위한 탈황 기술 동향)

  • Park, Jo-Yong;Kim, Jae-Kon;Yim, Eui-Soon;Jung, Choong-Sub
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.3
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    • pp.431-443
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    • 2013
  • Sulfur content of diesel fuel has been cut down to under 10 ppm ULSD (ultra low sulfur diesel) level by environmental regulation with the aim of reducing exhaust emissions. This review discusses the methods and principles of sulfur reduction in diesel and presents an overview of new approaches for ultra-deep desulfurization. The deep HDS (hydrodesulfurization) problems of diesel streams is exacerbated by the inhibiting effect of co-existing aromatics, nitrogen compounds and $H_2S$. The new approaches to deep desulfurization includes non-HDS type processing schemes such as adsorptive, extractive and oxidative desulfurization.

Tumor targeted gene therapy (종양 표적 유전자 치료)

  • Kang, Joo-Hyun
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.5
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    • pp.237-242
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    • 2006
  • Knowledge of molecular mechanisms governing malignant transformation brings new opportunities for therapeutic intervention against cancer using novel approaches. One of them is gene therapy based on the transfer of genetic material to an organism with the aim of correcting a disease. The application of gene therapy to the cancer treatment has led to the development of new experimental approaches such as suicidal gene therapy, inhibition of oncogenes and restoration of tumor-suppressor genes. Suicidal gene therapy is based on the expression in tumor cells of a gene encoding an enzyme that converts a prodrug into a toxic product. Representative suicidal genes are Herpes simplex virus type 1 thymidine kinase (HSV1-tk) and cytosine deaminase (CD). Especially, physicians and scientists of nuclear medicine field take an interest In suicidal gene therapy because they can monitor the location and magnitude, and duration of expression of HSV1-tk and CD by PET scanner.

Blind identification of nonminimum phase FIR systems from second-order statistics and absolute mean (2차 통계값과 절대평균을 이용한 비최소 위상 FIR 시스템의 미상 식별)

  • 박양수;박강민;송익호;김형명
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.357-364
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    • 1996
  • This paper presents a new blind identification method of nonminimum phase FIR systems without employing higher-order statistics. It is based on the observation that the absolute mean of a second-order white sequence can measure the higher-order whiteness of the sequence. The proposed method may be a new alternative way to the higher-order statistics approaches. Some computer simulations show that the absolute mean is exactly estimated and the proposed method can overcome the disadvantages of the higher-order statistics approaches.

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An Introduction to Systems Theory Approach to Accident Modeling and Its Applications (시스템 이론 기반의 안전사고 모델의 해석과 응용사례 소개)

  • Park, C.H.;Park, Y.W.
    • Journal of the Korean Society of Systems Engineering
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    • v.1 no.1
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    • pp.20-25
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    • 2005
  • This paper presents the general system theory and its applications to the safety analysis method that is a recent trend over the traditional event-driven model. This new model is known as STAMP(Systems Theory Accident Modeling and Process) proposed by Nancy G. Leveson in MIT. The new model has benefits o f systemic approaches concerning the system safety as a whole including the context it is in, its stimulants and outcomes, and its parts as well as the relationships among them in a holistic manner. The method consists of a hierarchical control structure, a process model, and the safety constraints governing the control. This paper demonstrates an example that contrasts the differences between the approaches of STAMP and the traditional safety models.

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The Use of MSVM and HMM for Sentence Alignment

  • Fattah, Mohamed Abdel
    • Journal of Information Processing Systems
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    • v.8 no.2
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    • pp.301-314
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    • 2012
  • In this paper, two new approaches to align English-Arabic sentences in bilingual parallel corpora based on the Multi-Class Support Vector Machine (MSVM) and the Hidden Markov Model (HMM) classifiers are presented. A feature vector is extracted from the text pair that is under consideration. This vector contains text features such as length, punctuation score, and cognate score values. A set of manually prepared training data was assigned to train the Multi-Class Support Vector Machine and Hidden Markov Model. Another set of data was used for testing. The results of the MSVM and HMM outperform the results of the length based approach. Moreover these new approaches are valid for any language pairs and are quite flexible since the feature vector may contain less, more, or different features, such as a lexical matching feature and Hanzi characters in Japanese-Chinese texts, than the ones used in the current research.

Novel computational approaches characterizing knee physiotherapy

  • Kim, Wangdo;Veloso, Antonio P.;Araujo, Duarte;Kohles, Sean S.
    • Journal of Computational Design and Engineering
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    • v.1 no.1
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    • pp.55-66
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    • 2014
  • A knee joint's longevity depends on the proper integration of structural components in an axial alignment. If just one of the components is abnormally off-axis, the biomechanical system fails, resulting in arthritis. The complexity of various failures in the knee joint has led orthopedic surgeons to select total knee replacement as a primary treatment. In many cases, this means sacrificing much of an other-wise normal joint. Here, we review novel computational approaches to describe knee physiotherapy by introducing a new dimension of foot loading to the knee axis alignment producing an improved functional status of the patient. New physiotherapeutic applications are then possible by aligning foot loading with the functional axis of the knee joint during the treatment of patients with osteoarthritis.

Design Parameters of Polymers for Tissue Engineering Applications

  • Lee, Kuen-Yong
    • Macromolecular Research
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    • v.13 no.4
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    • pp.277-284
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    • 2005
  • The loss or failure of an organ or tissue can occur because of accident or disease, for which tissue or organ transplantation is a generally accepted treatment. However, this approach is extremely limited due to donor shortage. Tissue engineering is a new and exciting strategy, in which patients who need a new organ or tissue are supplied with a synthetic organ or tissue. In this approach, tissues are engineered using a combination of the patient's own cells and a polymer scaffold. The polymer scaffold potentially mimics many roles of extracellular matrices in the body. Various polymers have been studied and utilized to date in tissue engineering approaches. However, no single polymer has been considered ideal for all types of tissues and approaches. This paper discusses the design parameters of those polymers potentially useful in tissue regeneration.