• Title/Summary/Keyword: Mass changes

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On the natural frequencies and mode shapes of a multiple-step beam carrying a number of intermediate lumped masses and rotary inertias

  • Lin, Hsien-Yuan;Tsai, Ying-Chien
    • Structural Engineering and Mechanics
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    • v.22 no.6
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    • pp.701-717
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    • 2006
  • In the existing reports regarding free transverse vibrations of the Euler-Bernoulli beams, most of them studied a uniform beam carrying various concentrated elements (such as point masses, rotary inertias, linear springs, rotational springs, spring-mass systems, ${\ldots}$, etc.) or a stepped beam with one to three step changes in cross-sections but without any attachments. The purpose of this paper is to utilize the numerical assembly method (NAM) to determine the exact natural frequencies and mode shapes of the multiple-step Euler-Bernoulli beams carrying a number of lumped masses and rotary inertias. First, the coefficient matrices for an intermediate lumped mass (and rotary inertia), left-end support and right-end support of a multiple-step beam are derived. Next, the overall coefficient matrix for the whole vibrating system is obtained using the numerical assembly technique of the conventional finite element method (FEM). Finally, the exact natural frequencies and the associated mode shapes of the vibrating system are determined by equating the determinant of the last overall coefficient matrix to zero and substituting the corresponding values of integration constants into the associated eigenfunctions, respectively. The effects of distribution of lumped masses and rotary inertias on the dynamic characteristics of the multiple-step beam are also studied.

Hoarse Speech Analysis Using Dissymmetric Four-Mass Model of Vocal Cords (비대칭 4 질량 성대 모델에 의한 쉰목소리 분석)

  • Jiang, Gan-Yi;Chen, Hui-Fang;Choi, Tae-Young
    • The Journal of the Acoustical Society of Korea
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    • v.14 no.5
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    • pp.94-101
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    • 1995
  • In this paper, a new vocal cords model, called a four-mass model, is proposed for a hoarse speech mechanism. Pathological changes of vocal cords cause hoarse speech and glottal waveform reflects motion states of vocal cords. From these facts, we assumed that the morbid vocal cords be dissymmetric and take the four-mass type. The glottal waveforms and the model parameters of normal and hoarse speech signals are analyzed, and some relations bet ween the model parameters and the hoarse pathology are discussed. Experimental results show that the new research method of hoarse speech can reveal relations between the acoustic features of hoarse speech and the hoarse pathology, and be used to diagnose laryngeal diseases and to improve tone quality of hoarse speech.

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Application of MALDI Tissue Imaging of Drugs and Metabolites: A New Frontier for Molecular Histology

  • Shanta, Selina Rahman;Kim, Young-Jun;Kim, Young-Hwan;Kim, Kwang-Pyo
    • Biomolecules & Therapeutics
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    • v.19 no.2
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    • pp.149-154
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    • 2011
  • Matrix assisted laser desorption ionization (MALDI) mass spectrometry is commonly used to analyze biological molecules such as proteins, peptides and lipids from cells or tissue. Recently MALDI Imaging mass spectrometry (IMS) has been widely applied for the identification of different drugs and their metabolites in tissue. This special feature has made MALDI-MS a common choice for investigation of the molecular histology of pathological samples as well as an important alternative to other conventional imaging methods. The basic advantages of MALDI-IMS are its simple technique, rapid acquisition, increased sensitivity and most prominently, its capacity for direct tissue analysis without prior sample preparation. Moreover, with ms/ms analysis, it is possible to acquire structural information of known or unknown analytes directly from tissue sections. In recent years, MALDI-IMS has made enormous advances in the pathological field. Indeed, it is now possible to identify various changes in biological components due to disease states directly on tissue as well as to analyze the effect of treated drugs. In this review, we focus on the advantages of MALDI tissue imaging over traditional methods and highlight some motivating findings that are significant in pathological studies.

A Study on Kitsch in Modern Fashion (현대패션에 표현된 키치(Kitsch)연구)

  • 김경옥
    • Journal of the Korean Society of Costume
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    • v.47
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    • pp.143-160
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    • 1999
  • The purpose of this dissertation is to interpret fashion through a socio-cultural phenomenon called kitsch by understanding its aesthetic characteristics and clarifying its significance in the modern consumer society and analyzing the examples of kitsch appearing in modern fashion. The following are the arguments and conclusion of this dissertation. First kitsch has negative meanings such as aesthetic inadequacy or bad tastes implying vulgar popular tastes of faked sensations just imitating elite culture and using things indiscriminately for inferior reproduction or at best the philosophical and aesthetic category that expresses the mass of people's attitudes toward life in accepting the consumer culture of the industrial society. It started from the art of romanticism accompanied by th commercializing of art with the bourgeois society background formed in the mid-19th century. Though kitsch started to prevail following the socio-cultural changes caused by the Industrial Revolution in the 19th century it is only in the late 20th century that kitsch has come tc our everyday life and has become an object of aesthetic arguments. Second formative characteristics of kitsch appearin in fashion have a cumulative inadequate romantic pleasure-seeking satirizing and multicomplex nature. Third the socio-cultural meanings of kitsch appearing in fashion are as follows: The extension of commercialism which gratifies the pleasure-seeking mass consumers the enlargement of the aesthetic category by inclining to everyday commonplace aesthetic sense the expression of one's identity through the gratification of desire and the new aesthetics of resistance and deviance by an anti-traditional and anti-elite tendency towards the traditional society and aesthetic values.

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Free Vibration Analysis of a Stepped Cantilever Beam with a Mass and a Spring at the End (끝단에 스프링과 질량을 가진 단진보의 자유진동해석)

  • Yu, Chun-Seung;Hong, Dong-Pyo;Chung, Tae-Jin;Chung, Kil-To
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.9
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    • pp.2812-2818
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    • 1996
  • A cantilever beam with a mass and a spring at the end can be use to model a miniature flexible arm. It is necessary to know the natural frequencies and mode shapes to discuss its free vibration, especially when modal analysis is employed. A beam is clamped-free. In this paper we look at the lateral vibration of beams that have step changes in the properties of their cross sections. The frequency equation is derived by Bernoulli-Euler formulation and is sloved by the separation of variable. The parameters of the beam, 'mass and spring stiffness' are defined as nondimensionalized parameters for wide application of the results. According to the change of eigenvalues and mode shape are presented for this beam. The results presented are the eigenvalues and the natural frequencies for the first three modes of vibration. Results show that the parameters have a significant effect on the natural frequency.

Preserved Respiratory Function after Reconstruction of a Large Chest Wall Defect

  • Kim, Yu Jin;Kim, Yoon Ji;Lee, Jae-Ik
    • Archives of Reconstructive Microsurgery
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    • v.24 no.1
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    • pp.28-31
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    • 2015
  • A case report of a patient who developed radiation-induced sarcoma in the left chest wall is presented. The patient had partial mastectomy and adjuvant radiation therapy (total dose, 5,220 cGy) and chemotherapy. Five years later, she visited with rapidly growing mass with central ulceration in the irradiated chest wall. The mass was diagnosed as malignant fibrous histiocytoma. The chest wall mass resected en bloc ($23{\times}18cm$) including five consecutive ribs. After the defected thoracic cage was reinforced using a polytetrafluoroethylene patch, omental flap and split thickness skin graft was done for soft tissue coverage. We applied negative pressure wound closer system for effective suction of omeantal exudate. The wound healed without complications. The patient suffered no perioperative pulmonary complications. Pulmonary function tests showed no significant changes. Each of Gore-Tex, omental flap, negative pressure wound therapy and skin graft is widely used method. However, If these methods are used in combination, we can reconstruct the large defect of chest wall including multiple ribs without any repiratory function problems.

Identification of Marker Compounds for Discriminating between Embryogenic and Nonembryogenic Calluses of Higher Plants Using Pyrolysis Gas Chromatography Mass Spectrometry and Genetic Programming

  • Kim Suk-Weon;Ban Sung-Hee;Yoo Ook-Joon;Liu Jang-Ryol
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.1
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    • pp.38-42
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    • 2006
  • When whole cells are subjected to pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) analysis, it provides biochemical profiles containing overlapping signals of the majority of compounds. To determine marker compounds that discriminate embryogenic calluses from nonembryogenic calluses, samples of embryogenic and nonembryogenic calluses of five higher plant species were subjected to Py-GC/MS. Genetic programming of Py-GC/MS data was able to discriminate embryogenic calluses from nonembryogenic calluses. The content ratio of 5-meyhyl-2-furancarboxaldehyde and 5-(hydroxymethyl)-2-furancarboxaldehyde was greater in nonembryogenic calluses than in embryogenic calluses. However, the content ratio of phenol, p-cresol, and $^1H-indole$ in embryogenic calluses was 1.2 to 2.4 times greater than the ratio in nonembryogenic calluses. These pyrolysates seem to be derived from the components of the cell walls, which suggests that differences in cell wall components or changes in the architecture of the cell wall playa crucial role in determining the embryogenic competence of calluses.

Low Intensity Resistance Exercise Training with Blood Flow Restriction: Insight into Cardiovascular Function, and Skeletal Muscle Hypertrophy in Humans

  • Park, Song-Young;Kwak, Yi Sub;Harveson, Andrew;Weavil, Joshua C.;Seo, Kook E.
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.3
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    • pp.191-196
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    • 2015
  • Attenuated functional exercise capacity in elderly and diseased populations is a common problem, and stems primarily from physical inactivity. Decreased function and exercise capacity can be restored by maintaining muscular strength and mass, which are key factors in an independent and healthy life. Resistance exercise has been used to prevent muscle loss and improve muscular strength and mass. However, the intensities necessary for traditional resistance training to increase muscular strength and mass may be contraindicated for some at risk populations, such as diseased populations and the elderly. Therefore, an alternative exercise modality is required. Recently, blood flow restriction (BFR) with low intensity resistance exercise (LIRE) has been used for such special populations to improve their function and exercise capacity. Although BFR+LIRE has been intensively studied for a decade, a comprehensive review detailing the effects of BFR+LIRE on both skeletal muscle and vascular function is not available. Therefore, the purpose of this review is to discuss previous studies documenting the effects of BFR+LIRE on hormonal and transcriptional factors in muscle hypertrophy and vascular function, including changes in hemodynamics, and endothelial function.

Inflammatory pseudotumor of the midfacial area (중안면부에 발생한 염증성 가종양)

  • Ahn Hyoun-Suk;Choi Sun-Young;Koh Kwang-Joon
    • Imaging Science in Dentistry
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    • v.31 no.2
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    • pp.121-127
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    • 2001
  • Inflammatory pseudotumor was originally described in the lung, but recently has been recognized to occur in various sites. A 56-year-old female was referred to our department with a painless swelling of the right midfacial area since 3 months ago. Clinical examination showed non-specific intraoral findings, but asymmetric facial appearance and numbness of the right midfacial area. Plain radiographs and CT images showed aggressive destruction and irregular thickening of the right maxillary sinus wall, increased antral opacification, and destruction of the zygomatic arch. A relatively well-defined soft tissue mass occupied the right maxillary sinus, nasal cavity, zygoma, and infraorbital region. The soft tissue mass showed mild enhancement on CT. Radiographically, this lesion presented a rapidly enlarging mass demonstrating aggressive behavior, mimicking a malignant tumor. Histopathologic examinations showed plasma cells and inflammatory cells in variable fibrotic tissues and demonstrated positive reactivity for vimentin. No malignent changes could be found.

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Effect of Mg content on the density and critical properties of in-situ reacted MgB2 bulk superconductor

  • Jun, Byung-Hyuk;Kim, Dan-Bi;Park, Soon-Dong;Kim, Chan-Joong
    • Progress in Superconductivity and Cryogenics
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    • v.16 no.1
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    • pp.19-22
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    • 2014
  • The effects of Mg content on the pore formation, density and critical properties were investigated in in-situ reacted $MgB_2$ superconductors. The $Mg_{1+x}B_2$, (x=-0.2, 0.0, 0.05, 0.3, 1.0) bulk samples with different Mg contents were heat-treated at $900^{\circ}C$ for 1 h in an Ar atmosphere. The dimensional changes of a pellet's mass and volume after heat-treatment were measured. After heat-treatment process, the sample mass was decreased by Mg evaporation, but the sample volume was expanded by pore formation at the Mg site; therefore, the apparent density was decreased. Spherical pores the same as Mg particles were developed after heat-treatment in all samples, and the pore density was increased with increasing Mg content. As the x of Mg content was increased to 1.0, the apparent density of $Mg_{1+x}B_2$ samples was decreased due to a relatively larger reduction in a mass change. The critical current density of Mg excessive sample of x=0.05 showed the highest values over the applied magnetic fields because the excessive Mg may compensate Mg loss and enhance grain connectivity.