• Title/Summary/Keyword: Mass Law Deviation

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Sound Insulation Strategy of the Side Panels in a Tilting Train (틸팅열차 측면재의 차음 전략)

  • Kim, Seockhyun;Seo, Taegun
    • Journal of Industrial Technology
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    • v.31 no.A
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    • pp.33-38
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    • 2011
  • In an express tilting train, side wall insulating the noise from the exterior sound source consists of two parts. One is the layered composite panel including aluminum honeycomb, glass wool and nomex honeycomb. The other is the double glazed window. In this study, sound insulation performance of the two parts is investigated by mass law and experiment. Based on ASTM E2249-02, the intensity sound transmission loss (TL) is measured on the specimens of the two parts. Mass law deviation (MLD) is considered in order to compare the sound insulation performance in respect of weight. Contribution of each part to the sound insulation is analyzed and the sound insulation strategy for the interior noise reduction is investigated.

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Sound Insulation Performance of the Foamed Aluminum Sandwich Panel for a Railway Vehicle (발포 알루미늄 샌드위치 패널의 차음성능)

  • Ahn, Yong-Chan;Lee, Joong-Hyuk;Byeon, Jun-Ho;Kim, Seock-Hyun
    • Journal of Industrial Technology
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    • v.37 no.1
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    • pp.1-4
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    • 2017
  • Speeding up of railway vehicles requires weight reduction of the vehicle body. However, when the vehicle body is lighter, the sound insulation performance for blocking the noise from the outside is reduced. Aluminum is an important material used in the bodywork of transportation vehicles such as railway vehicles, aircraft, and automobiles. In this study, the bending stiffness and sound insulation performance of foamed aluminum with sandwich structure are investigated experimentally. The transmission loss is measured in accordance with the international standard ASTM E 2249-02. The mass-law deviation is used to evaluate the sound insulation performance per weight. In order to examine the applicability of the foamed aluminum sandwich panel to railway vehicles, the analysis of bending stiffness and an experimental review are carried out at the same time.

A Generalized Flow Model and Flow Charts for Predicting Mass Flow Rate through Short Tube Orifices (일반화된 오리피스의 유량예측 상관식 및 유량선도)

  • Choi Jong Min;Kim Yongchan;Kwak Jae Su;Kwon Byong Cheol
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.10
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    • pp.895-900
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    • 2004
  • With the phaseout of CFC and HCFC refrigerants, refrigeration and heat pump systems must be redesigned to match and improve system performance with alternative refrigerants. A generalized flow model for predicting mass flow rate through short tube orifices is derived from a power law form of dimensionless parameters generated by Pi-theorem. The database for developing the correlation includes extensive experimental data for R12, R22, R134a, R407C, R410A, and R502 from the open literature. The correlation yields an average deviation of $0.3\%$ and a standard deviation of $6.1\%$ based on the present database. In addition, rating charts for predicting refrigerant flow rate through short tube orifices are generated for R12, R22, R134a, R407C, R410A, and R502.

Sound Insulation Performance of Honeycomb Composite Panel for a Tilting Train (틸팅 열차용 허니콤 복합 적층재의 차음성능)

  • Kim, Seock-Hyun;Seo, Tae-Gun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.12
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    • pp.1931-1936
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    • 2010
  • In Korean tilting trains, honeycomb composite panels are used for high speed and light weight. The side wall of a tilting train consists of an aluminum honeycomb coated with carbon-fiber-reinforced epoxy skin and a nomex honeycomb panel as the main structure, with glass wool inserted between the panels. In this study, based on ASTM E2249-02, we measure the intensity sound transmission loss (TL) of the honeycomb composite panels. Using mass law deviation (MLD), we estimate the sound insulation performance of the honeycomb composite panels in terms of their weight and explore the feasibility of substituting a conventional corrugated steel panel. The transmission-loss data of the honeycomb composite panels obtained in the study will be used to establish noise-reduction measures for train compartments.

Sound Insulation Performance of the Side Layered Panels in the Next Generation High Speed Train (차세대 고속철도 차량 측면 적층재의 차음성능)

  • Lee, Joong-Hyeok;Lee, Ho-Jin;Park, In-Seok;Kim, Seock-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.457-462
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    • 2011
  • The sidewall of the HEMU-400x consists of two parts. One is the multi-layered structure including aluminium extruded panel and the other is the double glazed window. When the train runs in a tunnel, the equivalent sound insulation performance of the side wall significantly influences the internal noise levels. In aspect of the sound insulation strategy, it is important to make two parts have similar performance. In this study, the intensity sound transmission loss (ITL) is measured on the specimens of the two parts. Mass law deviation (MLD) is considered in order to compare the sound insulation performance of the two parts in respect of the weight. Contribution of each part to the sound insulation is analyzed and the sound insulation strategy is investigated to reduce the interior noise.

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Performance of Short Tube Orifices Using R-410A Near the Critical Region (R-410A 임계영역 운전조건에서 오리피스의 성능특성에 관한 연구)

  • Choi, Jong-Min;Kim, Yong-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.12
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    • pp.1106-1112
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    • 2005
  • An experimental investigation was performed to develop an empirical correlation of R-410A flowing through short tube orifices working near the critical region. Tests were executed by varying upstream pressure from 2,619 kPa to 4,551 kPa, and upstream subcooling from 2.8 and $11.1^{\circ}C$. The experimental data were represented as a function of major operating parameters and short tube diameter. As compared to mass flow trends at normal upstream pressures, flow dependency on upstream subcooling became more significant at high upstream pressures due to a higher density change. Based on the database obtained from this study and literature, an empirical correlation was developed from a power law form of dimensionless parameters generated by the Buckingham Pi theorem. The correlation yielded good agreement with the data. Approximately $92\%$ of the data were correlated within a relative deviation of $5\%$.

Review of U.S. Courts' Procedural and Substantive Unconscionability Doctrine Regarding Mandatory Arbitration Agreement in the Nursing Home Contracts (미국 요양원 입소계약상의 강제적 중재 조항에 관한 미국 법원의 절차적, 실체적 비양심성 법리 고찰)

  • Shin, Seungnam
    • Journal of Arbitration Studies
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    • v.31 no.1
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    • pp.83-105
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    • 2021
  • If aggrieving consumers or employees cannot prove both substantive and procedural unconscionability, many U.S. state courts will enforce arbitration agreements. Additionally, U.S. courts weigh a variety of factors to determine whether an arbitration agreement is substantively unconscionable. For example, U.S. courts have considered one or a combination of the following factors: (1) the fairness of contractual terms; (2) the severity of contractual terms' deviation from prevailing standards, customs, or practices within a particular industry; (3) the reasonableness of goods-and-services contract prices; (4) the commercial reasonableness of the contract terms; (5) the purpose and effect of the terms and (6) "the allocation of risks between the parties." Further, procedural unconscionability characterized by surprise or lack of knowledge focuses on terms that are deceptively hidden in a mass of contract language, the object of another concealment, or imposed in the circumstances involving haste or high-pressure tactics so that they are not likely to be read or understood. This unconscionability doctrine can be applied to a situation where an alcoholic dementia-afflicted older adult is admitted to a nursing home. At that time, because she had alcoholic dementia, which precluded her reading, comprehending, writing, negotiating, or signing of any legal document, her son, who did not understand the adhesion contract, signed the standardized residential contract and the arbitration agreement.