• Title/Summary/Keyword: empirical ratio

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Estimation of fundamental natural period of vibration for reinforced concrete shear walls systems

  • Shatnawi, Anis S.;Al-Beddawe, Esra'a H.;Musmar, Mazen A.
    • Earthquakes and Structures
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    • v.16 no.3
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    • pp.295-310
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    • 2019
  • This study attempts to develop new simplified approximate formulas to predict the fundamental natural periods of vibration (T) for bearing wall systems engaged with special reinforced concrete shear walls (RCSW) under seismic loads. Commonly, seismic codes suggested empirical formulas established by regression analysis of measured T for buildings during earthquake motions. These formulas depend on structure type, building height, number, height and length of SW, and ratio of SW area to base area of structure. In this study, a parametric investigation is performed for T of 110 selected models of bearing RCSW systems with varying structural height, configuration of horizontal plans including building width, number and width of bays, presence of middle corridors and core SWs. For this purpose, a 3D non-linear response time history (TH) analysis is implemented using ETABS v16.2.1. New formulas to estimate T are anticipated and compared with those obtained from formulas of IBC 2012 and ASCE/SEI 7-10. Moreover, the study examines responses of an arbitrarily two selected test model of 60 m and 80 m in height with presence of SWs having middle corridors. It is observed that the performance of the tested buildings is different through arising of considerable errors when using codes' formulas for estimating T. Accordingly, using the present proposed formulas exhibits more reasonable and safer design compared to codes' formulas. The results showed that equitable enhancement is promising to improve T formulas approaching enhanced and accurate estimation of T with reliable analysis, design, and evaluation of bearing RCSW systems.

A Study of The Influential Factors of Efficiency in Korean and Chinese Banks (한국과 중국 은행산업의 효율성 영향요인에 관한 실증분석)

  • Zhu, Hui-Qin;Li, Ming-Ji
    • International Area Studies Review
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    • v.16 no.3
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    • pp.99-118
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    • 2012
  • This study have done comparative analysis of Korean banks' restructure and Chinese banks' reformation, especially derives main factors that influence existence and improvement of competitiveness of Korean banks. The study measured effectiveness of 15 Chinese banks and 13 Korean banks, and conducted empirical analysis of what are the factors affect the efficiency of banks. The result and implication are as follow. First, Korean commercial banks' efficiency is higher than banks in China, but Chinese commercial banks are getting better every year. Second, as the factors affect efficiency of the banks, it shows that the scale of bank, asset reliabilities, ownership structure and financial performance are significant. Third, about the factors affect efficiency, the ownership structure, financial intermediation ratio, and the health of the assets are significant in Chinese banks. Fourth, about the factors affect efficiency, the financial performance and asset reliability are significant in Korean banks. Based on the results, we have identified current problems of Chinese and Korean banks, and also pointed out Korean banks and Government how to improve competitiveness of Bank industry.

An Empirical Study on the Effect of Chinese Regional Income Disparity from Globalization (세계화가 중국 지역간 소득불균형에 미치는 영향에 관한 실증분석)

  • Lee, Min-Hwan;Zhu, Shiyou
    • International Area Studies Review
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    • v.13 no.3
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    • pp.73-91
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    • 2009
  • In this paper, we attempt to study the trend of regional disparity among Chinese provinces and examine the effects of globalization on the disparities adapting panel data approach. The panel data set utilized consists of the annual variables of 29 provinces during 18 years from 1990 to 2007. The trend of inter-provincial disparities in the 1990s with the expansive trend but the trend has started to decrease since 2000. The results of the China case study show clearly that the provincial international trade level and ratio variables perform on regional income disparities remarkably in all cases. It means that the large development of international trade do with increased among provincial disparity. While due to the large area in the provinces, there exist urban-rural disparities within provinces could be one of the main source of regional disparities. Therefore, along with western regions development policy various development policies against small cities are necessary for balanced regional economic growth in China.

Spatial Typification based on Heat Balance for Improving Thermal Environment in Seoul (열수지를 활용한 서울시 열환경 개선을 위한 공간 유형화)

  • Kwon, You Jin;Ahn, Saekyul;Lee, Dong Kun;Yoon, Eun Joo;Sung, Sunyong;Lee, Kiseung
    • Journal of Korea Planning Association
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    • v.53 no.7
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    • pp.109-126
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    • 2018
  • The purpose of this study is to identify the spatial types for thermal environment improvement considering heat flux and its spatial context through empirical orthodox formulas. First, k-means clustering was used to classify values of three kinds of heat flux - latent, sensible and storage heat. Next, from the k-means clustering, we defined a type of thermal environment (type LHL) where improvement is needed for more comfortable and pleasant thermal environment in the city, among the eight types. Lastly, we compared and analyzed the characteristics of each classified thermal environmental types based on land cover types. From the study, we found that the ratio of impervious surfaces, roads, and buildings of the type LHL is higher than those of the type HLH (relatively thermal comfort environment). In order to improve the thermal environment, the following contents are proposed to urban planners and designers depending on the results of the study. a) Increase the green zone rate by 10% to reduce sensible heat; b) Reduce the percentage of impermeable surfaces and roads by 10% ; c) Latent heat increases when water and green spaces are expanded. This study will help to establish a minimum criterion for a land cover rate for the improvement of the urban thermal environment and a standard index for the thermal environmental improvement can be derived.

A Study of the Deregulation of New Apartment Sales Price and the Stock Price of Construction Firms (분양가 자율화와 건설회사의 주가)

  • Yang, Choonsik
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.5
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    • pp.3-11
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    • 2019
  • This study is designed to examine the stock price of construction firms which are affected by the deregulation of new apartment sales price. As empirical methodology, it uses the traditional event study analysis to test the influence of the deregulation of new apartment sales price and the regression analysis to test which variables are related. The results of this study are summarized as follows : First, the cumulative abnormal return of stock is positive when government announced the deregulation of new apartment sales price. The cumulative abnormal return of stock for 21 trading day before -10 to +10 day is 25.51% which is significant different from zero at 1 percent level. This result suggests that the deregulation of new apartment sales price conveys good information to stock market that the firms performance will be good in the future. Second, in the regression analysis this study shows that the cumulative abnormal return of stock is related to firm's profit margin ratio.

Effects of Non-aeronautical Revenue on Airport Charges: Moderation of Private Ownership (비항공수익이 공항사용료에 미치는 영향: 민간지분의 조절효과를 중심으로)

  • Shin, Taejin;Roh, Taewoo
    • Journal of Digital Convergence
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    • v.17 no.9
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    • pp.39-46
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    • 2019
  • This study started with the question of whether the percentage of non-aeronautical revenues at Incheon airport was extremely high when compared with other international airports. Although aeronautical revenues for the airport based on the traditional business model have the limits to grow due to various regulations, stakeholders concerned about improving the competitiveness recently have been interested in increasing non-aeronautical revenues. This study deals with the effect of non-aeronautical revenues at international airports on airport charges as the extent of airport privatization get stronger. To examine hypotheses, we collected international data from trustful sources. Finally, we conducted an empirical analysis of 178 airports worldwide. As a result, the higher the percentage of non-aeronautical revenues at international airports, the lower the airport charges were. Besides, the private equity ratio positively moderated the relationship between the percentage of non-aeronautical revenues and airport charges. Privatization of airports may offset the effects of reduced airport charges through increased commercial activity. Graphical display for moderation effect is offered to facilitate comprehension.

A new formulation for strength characteristics of steel slag aggregate concrete using an artificial intelligence-based approach

  • Awoyera, Paul O.;Mansouri, Iman;Abraham, Ajith;Viloria, Amelec
    • Computers and Concrete
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    • v.27 no.4
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    • pp.333-341
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    • 2021
  • Steel slag, an industrial reject from the steel rolling process, has been identified as one of the suitable, environmentally friendly materials for concrete production. Given that the coarse aggregate portion represents about 70% of concrete constituents, other economic approaches have been found in the use of alternative materials such as steel slag in concrete. Unfortunately, a standard framework for its application is still lacking. Therefore, this study proposed functional model equations for the determination of strength properties (compression and splitting tensile) of steel slag aggregate concrete (SSAC), using gene expression programming (GEP). The study, in the experimental phase, utilized steel slag as a partial replacement of crushed rock, in steps 20%, 40%, 60%, 80%, and 100%, respectively. The predictor variables included in the analysis were cement, sand, granite, steel slag, water/cement ratio, and curing regime (age). For the model development, 60-75% of the dataset was used as the training set, while the remaining data was used for testing the model. Empirical results illustrate that steel aggregate could be used up to 100% replacement of conventional aggregate, while also yielding comparable results as the latter. The GEP-based functional relations were tested statistically. The minimum absolute percentage error (MAPE), and root mean square error (RMSE) for compressive strength are 6.9 and 1.4, and 12.52 and 0.91 for the train and test datasets, respectively. With the consistency of both the training and testing datasets, the model has shown a strong capacity to predict the strength properties of SSAC. The results showed that the proposed model equations are reliably suitable for estimating SSAC strength properties. The GEP-based formula is relatively simple and useful for pre-design applications.

Biophilic Color Palette Development based on NeuroArchitecture towards Psychological Healing - Focused on the Landscape Painting of Impressionism 'Claude Monet' - (심리 치유를 위한 신경건축학 기반의 바이오필릭 색채 팔레트 정량화 - 인상주의 '모네'의 풍경화를 중심으로 -)

  • Choi, Yoon-Young;Lee, Hyun-Soo
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.2
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    • pp.43-52
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    • 2020
  • With the advent of the Fourth Industrial Revolution, people need healing. Research in neuroarchitecture shows that people feel happy and stable when working with nature, and patients heal quickly. Therefore, This study aims to quantitatively analyze the colors that help psychological healing in the painting images depicting nature by setting 'Natural Colors' of Biophilic Design as the subject of research. So the purpose of this study was to measure Biophilic Color and to develop Biophilic Color Palette. We extracted Biophilic colors using Impressionist Monet's Landscape painting. After extracting colors using Photoshop Color Picker, we converted RGB color code to NCS color code and Munsell color code. The results of this study were as follows; The ratio of Y was high in the GY-series and YR-series. This is due to the characteristic of impressionism that expresses the change of color by light in close relationship with light. Y is universally considered to be pleasant, representing happiness, sunshine and optimism. Therefore, it is possible to create an environment that helps psychological healing by utilizing the Y-series color palette. Average Blackness was 28. Average Chromaticness was 34.61. The significance of this study is to propose a biophilic color palette that is useful for psychological healing by quantifying the color code of biophilic colors depicted and expressed with adjective images and idiomatic color names. Quantitative and empirical studies on healing colors are needed continuously and should be actively utilized in healing environment planning.

Nurse Staffing and Patient Outcomes in Korea: A Systematic Review (간호인력과 환자결과: 체계적 문헌고찰)

  • Lee, Ji Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.104-115
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    • 2021
  • The purpose of this review was to systematically assess empirical studies on the relationship between nurse staffing and patient outcomes through systematic literature review. Peer-reviewed articles published between January 2009 and December 2018 were identified in CINAHL, Pubmed, EBSCOhost, RISS, and Dbpia databases. A total of 13 articles relating to nurse staffing and patient outcomes in Korea were systematically reviewed and analyzed. The review showed that better nurse staffing aligned with better patient outcomes. However, some studies did not directly correlate patient outcomes with nurse staffing. This is because each study examined varied aspects of nurse staffing and different patient outcomes. These inconsistent study results indicate that continuous study is required. There should be continued efforts to establish guidelines and strategies for deploying nurse staff by maintaining optimal patient-to-nurse ratio.

Stochastic analysis of the rocking vulnerability of irregular anchored rigid bodies: application to soils of Mexico City

  • Ramos, Salvador;Arredondo, Cesar;Reinoso, Eduardo;Leonardo-Suarez, Miguel;Torres, Marco A.
    • Earthquakes and Structures
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    • v.20 no.1
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    • pp.71-86
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    • 2021
  • This paper focuses on the development and assessment of the expected damage for the rocking response of rigid anchored blocks, with irregular geometry and non-uniform mass distribution, considering the site conditions and the seismicity of Mexico City. The non-linear behavior of the restrainers is incorporated to evaluate the pure tension and tension-shear failure mechanisms. A probabilistic framework is performed covering a wide range of block sizes, slenderness ratios and eccentricities using physics-based ground motion simulation. In order to incorporate the uncertainties related to the propagation of far-field earthquakes with a significant contribution to the seismic hazard at study sites, it was simulated a set of scenarios using a stochastic summation methods of small-earthquakes records, considered as Empirical Green's Function (EGFs). As Engineering Demand Parameter (EDP), the absolute value of the maximum block rotation normalized by the body slenderness, as a function of the peak ground acceleration (PGA) is adopted. The results show that anchorages are more efficient for blocks with slenderness ratio between two and three, while slenderness above four provide a better stability when they are not restrained. Besides, there is a range of peak intensities where anchored blocks located in soft soils are less vulnerable with respect to those located in firm soils. The procedure used in here allows to take decisions about risk, reliability and resilience assessment of different types of contents, and it is easily adaptable to other seismic environments.