• Smart Structures and Systems
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• 제19권6호
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• pp.633-641
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• 2017

The complexity of macro-fiber composite (MFC) materials increasing the difficulty in simulation and analysis of MFC integrated structures. To give an accurate prediction of MFC bonded smart structures for the simulation of shape and vibration control, the paper develops a linear electro-mechanically coupled static and dynamic finite element (FE) models based on the first-order shear deformation (FOSD) hypothesis. Two different types of MFCs are modeled and analyzed, namely MFC-d31 and MFC-d33, in which the former one is dominated by the $d_{31}$ effect, while the latter one by the $d_{33}$ effect. The present model is first applied to an MFC-d33 bonded composite plate, and then is used to analyze both active shape and vibration control for MFC-d31/-d33 bonded plate with various piezoelectric fiber orientations.

• Journal of Ecology and Environment
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• 제38권1호
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• pp.1-14
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• 2015

Whilst it is clear that increasing temperatures from global environmental change will impact the positions of alpine treelines, it is likely that a range of regional and local scaled factors will mediate the overall impact of global scale climate drivers. We summarized 12 categories of abiotic and biotic factors as 4 groups determining treeline positions. First, there are global factors related to climate-induced growth limitation and carbon limitation. Second, there are seven regional and local factors related to treeline dynamics including frost stress, topography, water stress, snow, wind, fire and non-fire disturbance. Third, species-specific factors can control treeline dynamics through their influence on reproduction and life history traits. Fourth, there are positive feedbacks in structuring the dynamics of treelines. Globally, the commonly accepted growth limitation hypothesis is that growth at a treeline is limited by temperature. Meanwhile, positive feedbacks between canopy cover and tree establishment are likely to control the spatial pattern and temporal dynamics of many treelines. The presence of non-linear dynamics at treelines has implications for the use of treelines as barometers of climate change because the lagged responses and abrupt shifts inherent in non-equilibrium systems may combine to mask the overall climate trend.

• The Journal of Asian Finance, Economics and Business
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• 제7권7호
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• pp.149-158
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• 2020

The purpose of this study was to investigate the impact of corporate governance index on the cost of equity in companies listed on the Tehran Stock Exchange. This study collects data from 975 observations during the period 2012 to 2018 to test the hypotheses using multiple linear regression model for the panel data. In this research, the independent variable of corporate governance index comprises of 27 specific corporate governance attributes. The results of hypothesis testing showed that corporate governance has a negative and significant effect on the rate of capital cost. In other words, the quality of corporate governance can lower the rate of capital cost. This result suggests that, by using a powerful corporate governance system and by declining the information asymmetry (increasing transparency) and agency conflict, we would be able to enhance the quality of financial reports. It would strengthen the capital market, attract financial suppliers and investors, and absorb the required financial resources of the firm by a lower rate. The findings of the study suggest that companies are able to reduce the cost of equity by establishing strong corporate governance. This conclusion suggests the importance and effectiveness of corporate governance in the cost of equity.

• 응용통계연구
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• 제21권6호
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• pp.947-957
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• 2008

비열등성 시험시에 치료군(treatment group)과 활성대조군(active control group)을 이용한 모형으로 Hauschke 등 (1999)이 제안한 모수적 검정법이 있다. 이 방법은 위약군(placebo group)과 직접적인 비교가 불가능하므로 Pigeot 등 (2003)이 세 군으로 확장한 검정법을 제안하였다. 그러나 이와 같은 두 검정법은 구체적인 분포가정이 필요하다. 이런 단점을 보완하기 위하여 본 논문에서는 비모수적 방법으로서 두 군 설계에 Wilcoxon 순위합 검정(Wilcoxon, 1945)을 이용한 방법을, 세 군 설계에 Scheirer 등 (1976)이 제안한 선형대비검정을 확장한 새로운 방법을 제안한다. 또한 모의실험을 통하여 모수적 방법과 비모수적 방법간의 검정력을 비교하였다.

• 한국해안해양공학회지
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• 제2권2호
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• pp.75-82
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• 1990

파고, 주기의 정보로서 수위변동η, 그 시간적분법η, 파향의 정보로서 수평방향 2성분 물입자속도 u, v의 4가지 시계열을 판정하여, narrow band-width frequency spectrum을 가지는 불규칙파의 포락파형(enveloped wave)을 구함으로서, 파고, 주기, 파향의 종합확률분포를 상세히 유도하여, 현지실측경과와 비교, 검토했다. 그 결과, 실측되어진 종합확률분포는 유도되어진 파고, 주기, 파향의 결합확률분포와 양호하게 일치하여 현지 불규칙파랑장에 있어서 충분한 정도로서 적용할 수 있다는 것을 알았다.

• Corrosion Science and Technology
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• 제10권6호
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• pp.189-193
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• 2011

In the current paper, we are reporting the results from an investigation of the surface and sub-surface oxidation of a TRIP steel containing 2 wt.% Mn and 0.5 wt.% Al with and without 0.03 wt.% Sb. The oxidizing conditions in the gas were successively varied in terms of the linear gas flow-rate and dew-point, from conditions were gas-phase mass transport limited conditions prevailed, to those were solid state processes became the rate determining conditions. It was found, that at sufficient low oxidizing conditions (defined as flow-rate/dew-point), the metal surfaces were clear of any external oxides, and as the oxidizing conditions were increased, Mn- and Si- oxide nodules formed along with magnetite. As the oxidizing conditions were increased further, a dense magnetite layer was present. The limits of the various regions were experimentally quantified and a proposed hypothesis for their occurrences is presented. No obvious effect of Sb was noted in this micro-structural research of the oxides that results from the various conditions investigated in this study.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.35-42
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• 2020

This study aims to investigate the relationship between the variables of Current Ratio (CR), Return-on-Equity (ROE), Return-on-Assets (ROA), Debt-to-Equity Ratio (DER), and Firm Size (FS) on Dividend Policy (DP) in real estate and property companies listed on the Indonesia Stock Exchange in the period 2016-2019, looking at nine real estate companies in Indonesia. The research methodology uses an explanatory analysis approach and linear regression. Based on the eligibility and homogeneity of the data, the number of sample companies selected was nine companies. The company's financial statement data derived from primary data obtained on the Indonesia Stock Exchange, such as current ratio (CR), return-on-equity (ROE), return-on-assets (ROA), debt-to-equity ratio (DER) and firm size and dividend policy variables. The data analysis procedure is first to transform financial data from the original ratio data into interval data and, then, transform it to ordinal data. Furthermore, the validity and reliability process are ignored because the data is primary. Finally, regression testing is part of the hypothesis testing stage. The results of this study showed that the CR, ROE, and firm size had no positive and significant effect on dividend policy. In contrast, DER and ROA have a positive and significant impact on dividend policy.

• The Korean Journal of Ecology
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• 제9권3호
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• pp.135-147
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• 1986

The simplification and the searching trends of complex data which assumed relationship between predictor variables and object variables are one of primary objective of ecological research. This study was aimed to apply cononical analysis consisting of canonical correlation analysis and canonical variate analysis related to lichen vegetation and several environmental variables which are elevation, height on grond, exposure side and cover values. Data collected from the Duckyoo National Park in August 1985. Lichen species was ranked by eqivocation information theory with cover values. Canonical correlation analysis was applied to one data set both set both environmental variables and lichem family. In order to make two sets of data matrix the scale of position vector ordination was calculated from the vector scalar product for lichen species. Canonical variate analysis was applied to rearranged data which was made by interval class code for environmental variables. The sharpness values was calculated in frequency of cotingency tables and the dispersion profiles of each species in classes of environmental variables was designed to extract component values based on the decomposition of expected frequencies in contingency table. The results of canonical correlation analysis revealed canonical first correlation value 0.815(89%), and second correlation value 0.083(11%). Significance test showed that the hypothesis of joint mutuallity of canonical correlation is accepted (P>0.05). The relation between canonical score of vegetation variables and that of environmental variable indicated linear tendency.

• Journal of Communications and Networks
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• 제6권1호
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• pp.68-77
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• 2004

In the near future packet networks should support applications which can not predict their traffic requirements in advance, but still have tight quality of service requirements, e.g., guaranteed bandwidth, jitter, and packet loss. These dynamic characteristics mean that the sources can be made to modify their data transfer rates according to network conditions. Depending on the customer&; needs, network operator can differentiate incoming connections and handle those in the buffers and the interfaces in different ways. In this paper, dynamic QoS-aware scheduling algorithm is presented and investigated in the single node case. The purpose of the algorithm is in addition to fair resource sharing to different types of traffic classes with different priorities ?to maximize revenue of the service provider. It is derived from the linear type of revenue target function, and closed form globally optimal formula is presented. The method is computationally inexpensive, while still producing maximal revenue. Due to the simplicity of the algorithm, it can operate in the highly nonstationary environments. In addition, it is nonparametric and deterministic in the sense that it uses only the information about the number of users and their traffic classes, not about call density functions or duration distributions. Also, Call Admission Control (CAC) mechanism is used by hypothesis testing.

• 한국식생활문화학회지
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• 제34권5호
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• pp.567-576
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• 2019

The purpose of this study is to identify the impact of the performance-linked marketing of food companies on the satisfaction and willingness of the companies that purchase products. To achieve the purpose of this study, a survey was conducted on consumers who were using domestic coffee franchises. A total of 300 questionnaires were distributed, and only 291 were finally used for analysis, except for eight ones that were not sincere or valid. Performance-linked marketing consisted of promotional factors, support factors, production factors, and mouth-to-mouth factors, and the purchasing company's satisfaction and willingness to purchase products consisted of a single factor. A linear regression analysis was performed using SPSS version 20.0 to verify the hypothesis. The research results show that (1) marketing linked to the performance by coffee shops has a significant impact on consumers' willingness to purchase. (2) The marketing performance for coffee shops has a significant positive impact on the satisfaction of the purchasing company. (3) The consumer's intention to purchase has a significant positive effect on the purchaser's satisfaction. These findings confirm the importance of concert-linked marketing in the differentiated marketing by restaurant businesses.