• Title/Summary/Keyword: critical response

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Study on the Chirped Waveform of the USPR Pulse using the Impulse Response of a Waveguide

  • Roh, Young-Su
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.3
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    • pp.20-26
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    • 2010
  • In ultrashort-pulse reflectometry (USPR), a chirped waveform transformed from the USPR source impulse signal via waveguide makes it possible to employ millimeter-wave mixers for the frequency up-conversion process. Consequently, the frequency bandwidth of the USPR system is sufficiently wide to cover a large portion of the electron density profile of the plasma. Some physical aspects of the chirped waveform, such as maximum amplitude and length, are critical factors to determine the performance of the system. In this paper, the propagation of the USPR impulse signal through a rectangular waveguide is numerically studied to derive the chirped waveform using the impulse response of the waveguide. The results of numerical computation show that the chirped waveform significantly depends on the waveguide cutoff frequency as well as the waveguide length.

Study on Seismic Response Characteristics of Reactor Vessel Internals and Fuel Assembly for OBE Elimination

  • M. J. Jhung;Y. G. Yune;Lee, J. H.;Lee, J. B.
    • Nuclear Engineering and Technology
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    • v.29 no.5
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    • pp.417-431
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    • 1997
  • To resolve a general argument about OBE elimination for the future nuclear power plant design, seismic responses of reactor vessel internals and fuel assembly for Ulchin nuclear power plant units 3 and 4 in Korea are investigated as an example. Dynamic analyses of the coupled internals and core are performed for the seismic excitations using the reactor vessel motions. By investigating the response relations between OBE and SSE and their response characteristics, the critical components for OBE loading are addressed. Also the fuel assembly responses are calculated using the core plate motions and their behavior is found to be insignificant for OBE elimination.

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Study on the Transient Characteristics of the Sensor Tube of a Thermal Mass Flow Meter (열식 질량 유량계 센서관의 과도 특성에 관한 연구)

  • Kim, Dong-Kwon;Han, Il-Young;Kim, Sung-Jin
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.308-313
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    • 2003
  • Thermal mass flow meters (TMFMs) are most widely used for measuring mass flow rates in the semiconductor industry. A TMFM should have a short response time in order to measure the time-varying flow rate rapidly and accurately. Therefore it is important to study transient heat transfer phenomena in the sensor tube of a TMFM that is the most critical part in the TMFM. In the present work, a simple numerical model for transient heat transfer phenomena of the sensor tube of a TMFM is presented. Numerical solutions for the tube and fluid temperatures in a transient state are obtained using the proposed model and compared with experimental results to validate the proposed model. Based on numerical solutions, heat transfer mechanism in a transient state in the sensor tube is explained. Finally, a correlation for predicting the response time of a sensor tube is presented. The correlation is verified by experimental results.

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Optimization on Organoleptic Properties of Mushroom (Agaricus bisporus) Pickles using Response Surface Methodology (반응표면법을 이용한 양송이버섯 피클의 관능적 특성 최적화)

  • 김옥선;주나미
    • Korean journal of food and cookery science
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    • v.20 no.2
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    • pp.158-163
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    • 2004
  • The purpose of this study was to determine the organoleptic properties of mushroom pickles made at various compounding ratios according to central composite design for optimum organoleptic properties. In this study, various kinds of mushroom pickle were made at different compounding ratios of vinegar, sugar and salt-critical ingredients of the pickle recipe and the products were presented to an expert panel, who graded the subjects in 7 degrees for 5 items: color, flavor, hardness, taste and overall quality. As a result of sensory quality, mushroom pickles with 300g of vinegar, 150g of sugar and 60g of salt achieved the highest grade. Meanwhile, the results of Response Surface Methodology were different from the sensory quality results, showing that the optimum mixing conditions for overall organoleptic properties of mushroom pickle were 279.58g of vinegar, 179.34g of sugar and 59.09g of salt. (Ed- based on this conflict in results, I suggest that you make a final recommendation, of either the first, the second, or perhaps an intermediate, ratio)

Development of An Optimal Call-response Algorithm of Construction Lift for High-rise Building Construction (초고층 건설용 리프트의 최적 호출 응답 알고리즘 개발)

  • Ahn, Heejae;Lee, Dongmin;Kim, Taehoon;Cho, Hunhee;Kang, Kyung-In
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.6-7
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    • 2018
  • Although the importance of the construction lift is increasing, no improvements are being made to its operating system. This study proposed an optimal call-response algorithm of the construction lift for high-rise building construction by using image sensing technology, height measuring sensor, and load cell. This algorithm makes turn-around decision of the construction lift by considering the information and the number of user. It occurs when the call comes from a floor where the construction lift already have passed. The purpose of this study is to reduce the total latency of the construction lift user. Furthermore, it is possible to prevent delay in construction duration by carrying out a priority operation of the construction lift for the critical workforce.

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A Possible Physiological Role of Caspase-11 During Germinal Center Reaction

  • Kang, Shin-Jung
    • Animal cells and systems
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    • v.12 no.3
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    • pp.127-136
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    • 2008
  • Caspase-11 has been known as a dual regulator of cytokine maturation and apoptosis. Although the role of caspase-11 under pathological conditions has been well documented, its physiological role has not been studied much. In the present study, we investigated a possible physiological function of caspase-11 during immune response. In the absence of caspase-11, immunized spleen displayed increased cellularity and abnormal germinal center structure with disrupted microarchitecture. The rate of cell proliferation and apoptosis in the immunized spleen was not changed in the caspase-11-deficient mice. Furthermore, the caspase-11-deficient peritoneal macrophages showed normal phagocytotic activity. However, caspase-11-/-splenocytes and macrophages showed defective migrating capacity. The dysregulation of cell migration did not seem to be mediated by caspase-3, interleukin-$1{\alpha}$ or interleukin-$1{\beta}$ which acts downstream of caspase-11. These results suggest that a direct regulation of immune cell migration by caspase-11 is critical for the formation of germinal center microarchitecture during immune response. However, humoral immunity in the caspase-11-deficient mice was normal, suggesting the formation of germinal center structure is not essential for the affinity maturation of the antibodies.

A novel hydrogel-dispersed composite membrane of poly(N-isopropylacrylamide) in gelatin matrix and its thermally actuated permeation of 4-acetamidophen

  • Chun, Suk-Won;Kim, Jong-Duk
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.04a
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    • pp.50-51
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    • 1995
  • The swelling behavior of hyddrogels has been interested in many applications of drug carriers. These gels show reversible swelling changes in response to pH, electric currcnt, and temperature. Among others, the temperature-responsive behavior of poly(N-isopropylacrylanxide) (p(NIPAAm)) was studied, because a lower critical solution temperature(LCST) is in the vicinity of 32$\circ$C, and remarkable temperature-response can be obtained. We propose a novel composite membrane, which is appropriate for transporting drug ingredients above the transition temperature. Our object was to design a high permeation system above the shrinking temperature of p(NIPAAm). The membrane was composed of a matrix polymer and thermosensitive p(NIPAAm) hydrogel. The flux pattern of 4-acctamidophen through membrane in response of temperature was opposite to that of p(NIPAAm) membrane.

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A Study on the Response Characteristic Due to Unbalance Mass of Switched Reluctance Motor (SRM 회전자의 불평형에 의한 응답특성에 관한 연구)

  • Ha, K.H.;Kang, K.H.;Hong, J.P.;Kim, G.T.;Chang, K.C.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.67-69
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    • 1999
  • This study deals with the unbalance response of a rotor of Switched Reluctance Motor(SRM) due to unbalanced mass. The method to analyze SRM with rotor-bearing system is based on an extension of the well-known Transfer Matrix Method(TMM). Most of the calculation results present the natural frequencies as a function of the speed of rotation which yields critical speeds and response to unbalanced mass.

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Roles of Endoplasmic Reticulum Stress in Immune Responses

  • So, Jae-Seon
    • Molecules and Cells
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    • v.41 no.8
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    • pp.705-716
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    • 2018
  • The endoplasmic reticulum (ER) is a critical organelle for protein synthesis, folding and modification, and lipid synthesis and calcium storage. Dysregulation of ER functions leads to the accumulation of misfolded- or unfolded-protein in the ER lumen, and this triggers the unfolded protein response (UPR), which restores ER homeostasis. The UPR is characterized by three distinct downstream signaling pathways that promote cell survival or apoptosis depending on the stressor, the intensity and duration of ER stress, and the cell type. Mammalian cells express the UPR transducers IRE1, PERK, and ATF6, which control transcriptional and translational responses to ER stress. Direct links between ER stress and immune responses are also evident, but the mechanisms by which UPR signaling cascades are coordinated with immunity remain unclear. This review discusses recent investigations of the roles of ER stress in immune responses that lead to differentiation, maturation, and cytokine expression in immune cells. Further understanding of how ER stress contributes to the pathogenesis of immune disorders will facilitate the development of novel therapies that target UPR pathways.

Understanding the Unfolded Protein Response (UPR) Pathway: Insights into Neuropsychiatric Disorders and Therapeutic Potentials

  • Pitna Kim
    • Biomolecules & Therapeutics
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    • v.32 no.2
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    • pp.183-191
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    • 2024
  • The Unfolded Protein Response (UPR) serves as a critical cellular mechanism dedicated to maintaining protein homeostasis, primarily within the endoplasmic reticulum (ER). This pathway diligently responds to a variety of intracellular indicators of ER stress with the objective of reinstating balance by diminishing the accumulation of unfolded proteins, amplifying the ER's folding capacity, and eliminating slow-folding proteins. Prolonged ER stress and UPR irregularities have been linked to a range of neuropsychiatric disorders, including major depressive disorder, bipolar disorder, and schizophrenia. This review offers a comprehensive overview of the UPR pathway, delineating its activation mechanisms and its role in the pathophysiology of neuropsychiatric disorders. It highlights the intricate interplay within the UPR and its profound influence on brain function, synaptic perturbations, and neural developmental processes. Additionally, it explores evolving therapeutic strategies targeting the UPR within the context of these disorders, underscoring the necessity for precision and further research to effective treatments. The research findings presented in this work underscore the promising potential of UPR-focused therapeutic approaches to address the complex landscape of neuropsychiatric disorders, giving rise to optimism for improving outcomes for individuals facing these complex conditions.