• Title/Summary/Keyword: panel contribution method

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Shear Strength of Vertical Joints in Precast Concrete Panel with Shear Key (전단키를 갖는 프리캐스트 콘크리트 패널 수직접합부의 전단강도)

  • Lee, Sang-Sup;Park, Keum-Sung;Bae, Kyu-Woong
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.9
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    • pp.151-158
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    • 2019
  • A concrete core is used widely as lateral stability systems in high-rise modular buildings. As an alternative to traditional cast in-situ core, the precast concrete(PC) method can accelerate the construction of reinforced concrete cores. A core composed of precast elements differs from a in-situ core in having connections between the precast elements. The typical vertical connection between PC panels is consisted of shear keys, loop bars, lacer bars and grout. In this study, the effect of vertical connection components on shear strength is investigated experimentally. The test results show that the contribution to the shear strength is greater in order of grout strength, shear keys, lacer bars and loop bars. In addition, the numerical models to estimate the shear strength according to two crack patterns in the vertical joint of the PC panels are derived. The feasibility of the numerical models is evaluated by comparing the estimated shear strength and the test results.

A Study on Ashing Effects of Atmospheric Plasma for the Cleaning of Flat Panel Display (평판 디스플레이 세정을 위한 상압 플라즈마 에싱효과에 관한 연구)

  • Huh, Yong-Jeong;Lee, Gun-Young
    • Journal of the Semiconductor & Display Technology
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    • v.7 no.2
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    • pp.35-38
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    • 2008
  • This study shows the improvement of PR-Ashing rates in semi-conductor process using Atmospheric Plasma. Taguchi method is used to improve Ashing rates of photo-resist that is spread on the surface of a wafer. Improvement of Ashing rates is acquired through the decision of the effective factors and suitable combination of the factors. The results show the contribution rate of each factor and the effectiveness of Plasma for PR-Ashing process in this system.

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The Effects of Profit-Sharing Schemes on Productivity through Firm's Contribution to the Employee Welfare Fund (사내근로복지기금제도를 통한 이윤공유참여의 생산성효과)

  • Cin, Beom Cheol
    • Journal of Labour Economics
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    • v.26 no.3
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    • pp.115-147
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    • 2003
  • This paper scrutinizes the robustness of the profit-sharing findings first employing an original panel data on the Employee Welfare Fund over the period from 1992 to 2000. In examining the effects of profit-sharing schemes on labor productivity, it controls for simultaneity among profit-sharing, production factors, and productivity using both the two-stage least squares procedure and the lagged variable method. The empirical results show that an increase in firm's contribution to the Employee Welfare Fund is associated with capital-embodied and disembodied productivity enhancement, which is both statistically and economically highly significant. The empirical results are in contrast with predictions of both agency and transaction cost theories, and they imply that more tax benefits and financial incentives for expansion of the Employee Welfare Fund should be required to get productivity gains.

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Effects of the structural strength of fire protection insulation systems in offshore installations

  • Park, Dae Kyeom;Kim, Jeong Hwan;Park, Jun Seok;Ha, Yeon Chul;Seo, Jung Kwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.493-510
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    • 2021
  • Mineral wool is an insulation material commonly used in passive fire protection (PFP) systems on offshore installations. Insulation materials have only been considered functional materials for thermal analysis in the conventional offshore PFP system design method. Hence, the structural performance of insulation has yet to be considered in the design of PFP systems. However, the structural elements of offshore PFP systems are often designed with excessive dimensions to satisfy structural requirements under external loads such as wind, fire and explosive pressure. To verify the structural contribution of insulation material, it was considered a structural material in this study. A series of material tensile tests was undertaken with two types of mineral wool at room temperature and at elevated temperatures for fire conditions. The mechanical properties were then verified with modified methods, and a database was constructed for application in a series of nonlinear structural and thermal finite-element analyses of an offshore bulkhead-type PFP system. Numerical analyses were performed with a conventional model without insulation and with a new suggested model with insulation. These analyses showed the structural contribution of the insulation in the structural behaviour of the PFP panel. The results suggest the need to consider the structural strength of the insulation material in PFP systems during the structural design step for offshore installations.

Seismic Performance Evaluation of Beam-Column Connection for Panel Zone Strength (패널존의 강도비에 따른 기둥-보 접합부의 내진성능 평가)

  • Kim, Sung-Young;Shin, Chang-Hoon
    • Journal of the Korean Society of Hazard Mitigation
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    • v.7 no.1 s.24
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    • pp.11-20
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    • 2007
  • The study proposes the method to cancel the scallop to avoid fracture of the circumstance of the scallop at H shape column-to-beam connection and reinforce at beam flange two faces with the cover plates and rib. A total of four specimens were tested to enhance seismic performance of building structure by reducing the frequency of stress concentration and preventing the brittle fracture of scallop. For this purpose, four full-scale test specimens were made and loaded with quasi-static reversed cyclic loading. The main analytical parameters are panel-zone-strength ratio, yield strengths, initial stiffness, total plastic rotation, contribution of each element to total plastic rotation and energy dissipation capability. For the specimens tested under repeated loading, the experimental result was satisfied with seismic performance requirement as the Special Moment Frames (SMF). The analysis results show that all of the test specimens were found to have good performance to 4% story drift and satisfied the criteria for the plastic roation capacity of SMFs that is 0.03 rad. according to the 1997 AISC seismic provision.

The Dynamic Effects of Globalization on the Firm Performance: A Study on Korea Maritime and Fishery Companies

  • Donghyun Lee;Heedae Park;Joongsan Ko
    • Journal of Korea Trade
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    • v.26 no.7
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    • pp.127-144
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    • 2022
  • Purpose - This study aimed to analyze the dynamic effects of progress in globalization on firm performance by employing individual companies' financial statement datasets. Design/methodology - The analysis leveraged the variables of operating revenue (OPRE) and pre-tax profit and loss (PLBT) as measurement variables for firm performance over 2011-2019. As a proxy variable for globalization, the trade index, a subordinate indicator of the KOF Globalization Index, was used. Through panel regression analysis, the relationship among those variables was ascertained, and the local projection (LP) method was subsequently utilized to identify dynamic effects. A subsample analysis was further performed by classifying companies based on their sizes and industries to determine the differential effects of globalization on each group. Findings - The panel regression analysis derived positive effects of an increasing degree of globalization on OPRE of Korea maritime and fishery firms. However, the impulse response functions, obtained from the LP, showed that in the short run, globalization affects PLBT negatively but in the long run, it gradually converted into a positive effect. In addition, according to the subsample analysis based on company size, the effects of globalization on OPRE became greater as each company became larger. Moreover, the industry-based analysis showed heterogeneous effects, depending on the industries in which the maritime and fishery companies operated. Originality/value - The analysis of the dynamic effects of globalization on firm performance, which revealed that the effects vary depending on the time points, is the important contribution of this study. The results also suggest that the effects of globalization vary depending on the company size and industry.

Prediction of Wind Farm Noise with Atmospheric Stability (대기 안정 상태에 따른 풍력 단지 소음 전파 예측)

  • Son, Eunkuk;Lee, Seunghoon;Jeon, Minu;Lee, Soogab
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.42.2-42.2
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    • 2011
  • Noise generated from wind turbines has been predicted by numerical methods. Sound pressure level(SPL) on the turbines is predicted after aerodynamic analysis is carried out by Wind Turbine Flow, Aeroacoustics and Structure analysis (WINFAS) code. The level of each panel of acoustic sphere is determined by the sum of tonal, turbulence ingestion and airfoil self noise. With the noise source database, the acoustic sphere, SPL on the ground is calculated using the model based on acoustic ray theory. The model has been designed to consider the effects on the condition of terrain and atmosphere. The variations of SPL on the ground occur not only because of the different source level but also because of the nonuniform distributions of the sound speed along the height. Hence, the profile of an effective sound speed which is the sum of the contribution of sound speed to a temperature gradient and a wind speed variation is used by the theory based on atmospheric stability. With the integrated numerical method, the prediction of sound propagation on the wind farm is carried out with the states of the atmospheric stability.

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The Influence of Corporate Governance on Dividend Decisions of Listed Firms: Evidence from Sri Lanka

  • NAZAR, Mohamed Cassim Abdul
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.289-295
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    • 2021
  • This study investigates the role of corporate governance in the dividend decision of 198 non-financial companies listed on the Colombo Stock Exchange of Sri Lanka, over the period from 2009 to 2016. Four corporate governance indicators are used in this study; managerial ownership, the board size, board independence, and CEO duality. Furthermore, this study considers three control variables such as profitability, firm size, and corporate tax. This study employed the Generalized Method of Moments (GMM) model to estimate the regression models on panel data study. The major contribution of this study is exploring the insight into the effect of corporate governance factors on dividend decisions. The results of the study revealed that managerial ownership showed a significant positive impact on the dividend payout ratio. Board size showed a significant positive influence on the dividend payout ratio. Board independence negatively but significantly influenced the dividend payout ratio. CEO duality showed an insignificant negative impact on the dividend payout ratio. In the framework of these CG indicators, Sri Lankan listed firms are recommended to have dispersed ownerships, large Board size and maintain a balance of power and authority by separating the individual who is assuming the position of the CEO from the Chairperson of the Board and maintain at least two independent directors.

Key Audit Matters Readability and Investor Reaction

  • CHIRAKOOL, Wichuta;POONPOOL, Nuttavong;WANGCHAROENDATE, Suwan;BHONGCHIRAWATTANA, Utis
    • Journal of Distribution Science
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    • v.20 no.9
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    • pp.73-81
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    • 2022
  • Purpose: This study aimed to examine whether key audit matters (KAMs) readability influences investor reaction. Research design, data, and methodology: The signaling theory was applied to explain the behavior of investors when they receive useful information for their decisions. Data were collected from 1,866 firm-year observations from Thai listed companies in both the Stock Exchange of Thailand (SET) and the Market for Alternative Investment (MAI) for the fiscal years of 2016-2019. The study was based on secondary data, which were collected from the SET Market Analysis and Reporting Tool (SETSMART) database and the Stock Exchange of Thailand's website (www.set.or.th). A statistical regression method was used with panel data analysis to evaluate possible associations between KAMs readability and investor reaction. The study relied on popular readability measures (Fog Index). Moreover, investor reaction was measured by absolute cumulative abnormal return and abnormal trading volume. Results: It was found that the KAMs readability has positive significance on both absolute cumulative abnormal return and abnormal trading volume. Conclusion: This study showed a significant contribution to the implication of KAMs in an emerging economy. The results reveal that more readable KAMs disclosure distributed new insights and useful information to investors and led to reducing the information gap between auditors and investors.

The Experimental Study on the Absorbed Energy of Carbon/Epoxy Composite Laminated Panel Subjected to High-velocity Impact (고속 충격을 받는 Carbon/Epoxy 복합재 적층판의 흡수 에너지 예측에 대한 실험적 고찰)

  • Cho, Hyun-Jun;Kim, In-Gul;Lee, Seokje;Woo, Kyeongsik;Kim, Jong-Heon
    • Composites Research
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    • v.26 no.3
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    • pp.175-181
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    • 2013
  • The evaluation and prediction for the absorbed energy, residual velocity, and impact damage are the key things to characterize the impact behavior of composite laminated panel subjected to high-velocity impact. In this paper, the method to predict the residual velocity and the absorbed energy of Carbon/Epoxy laminated panel subjected to high velocity impact are proposed and examined by using quasi-static perforation test and high-velocity impact test. Total absorbed energy of specimen due to the high-velocity impact can be grouped with static energy and kinetic energy. The static energy are consisted of energy due to the failure of the fiber and matrix and static elastic energy, which are related to the quasi-static perforation energy. The kinetic energy are consisted of kinetic energy of moving part of specimen, which are modelled by three modified kinetic model. The high-velocity impact test were conducted by using air gun impact facility and compared with the predicted values. The damage area of specimen were examined by C-scan image. In the high initial impact velocity above the ballistic limit, both the static energy and the kinetic energy are known to be the major contribution of the total absorbed energy.