Assessment of compressive strength of high-performance concrete using soft computing approaches
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- Computers and Concrete
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- v.33 no.1
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- pp.55-75
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- 2024
The present study introduces an optimum performance soft computing model for predicting the compressive strength of high-performance concrete (HPC) by comparing models based on conventional (kernel-based, covariance function-based, and tree-based), advanced machine (least square support vector machine-LSSVM and minimax probability machine regressor-MPMR), and deep (artificial neural network-ANN) learning approaches using a common database for the first time. A compressive strength database, having results of 1030 concrete samples, has been compiled from the literature and preprocessed. For the purpose of training, testing, and validation of soft computing models, 803, 101, and 101 data points have been selected arbitrarily from preprocessed data points, i.e., 1005. Thirteen performance metrics, including three new metrics, i.e., a20-index, index of agreement, and index of scatter, have been implemented for each model. The performance comparison reveals that the SVM (kernel-based), ET (tree-based), MPMR (advanced), and ANN (deep) models have achieved higher performance in predicting the compressive strength of HPC. From the overall analysis of performance, accuracy, Taylor plot, accuracy metric, regression error characteristics curve, Anderson-Darling, Wilcoxon, Uncertainty, and reliability, it has been observed that model CS4 based on the ensemble tree has been recognized as an optimum performance model with higher performance, i.e., a correlation coefficient of 0.9352, root mean square error of 5.76 MPa, and mean absolute error of 4.1069 MPa. The present study also reveals that multicollinearity affects the prediction accuracy of Gaussian process regression, decision tree, multilinear regression, and adaptive boosting regressor models, novel research in compressive strength prediction of HPC. The cosine sensitivity analysis reveals that the prediction of compressive strength of HPC is highly affected by cement content, fine aggregate, coarse aggregate, and water content.
1. Introduction Today Internet is recognized as an important way for the transaction of products and services. According to the data surveyed by the National Statistical Office, the on-line transaction in 2007 for a year, 15.7656 trillion, shows a 17.1%(2.3060 trillion won) increase over last year, of these, the amount of B2C has been increased 12.0%(10.2258 trillion won). Like this, because the entry barrier of on-line market of Korea is low, many retailers could easily enter into the market. So the bigger its scale is, but on the other hand, the tougher its competition is. Particularly due to the Internet and innovation of IT, the existing market has been changed into the perfect competitive market(Srinivasan, Rolph & Kishore, 2002). In the early years of on-line business, they think that the main reason for success is a moderate price, they are awakened to its importance of on-line service quality with tough competition. If it's not sure whether customers can be provided with what they want, they can use the Web sites, perhaps they can trust their products that had been already bought or not, they have a doubt its viability(Parasuraman, Zeithaml & Malhotra, 2005). Customers can directly reserve and issue their air tickets irrespective of place and time at the Web sites of travel agencies or airlines, but its empirical studies about these Web sites for reserving and issuing air tickets are insufficient. Therefore this study goes on for following specific objects. First object is to measure service quality and service recovery of Web sites for reserving and issuing air tickets. Second is to look into whether above on-line service quality and on-line service recovery have an impact on overall service quality. Third is to seek for the relation with overall service quality and customer satisfaction, then this customer satisfaction and loyalty intention. 2. Theoretical Background 2.1 On-line Service Quality Barnes & Vidgen(2000; 2001a; 2001b; 2002) had invented the tool to measure Web sites' quality four times(called WebQual). The WebQual 1.0, Step one invented a measuring item for information quality based on QFD, and this had been verified by students of UK business school. The Web Qual 2.0, Step two invented for interaction quality, and had been judged by customers of on-line bookshop. The WebQual 3.0, Step three invented by consolidating the WebQual 1.0 for information quality and the WebQual2.0 for interactionquality. It includes 3-quality-dimension, information quality, interaction quality, site design, and had been assessed and confirmed by auction sites(e-bay, Amazon, QXL). Furtheron, through the former empirical studies, the authors changed sites quality into usability by judging that usability is a concept how customers interact with or perceive Web sites and It is used widely for accessing Web sites. By this process, WebQual 4.0 was invented, and is consist of 3-quality-dimension; information quality, interaction quality, usability, 22 items. However, because WebQual 4.0 is focusing on technical part, it's usable at the Website's design part, on the other hand, it's not usable at the Web site's pleasant experience part. Parasuraman, Zeithaml & Malhorta(2002; 2005) had invented the measure for measuring on-line service quality in 2002 and 2005. The study in 2002 divided on-line service quality into 5 dimensions. But these were not well-organized, so there needed to be studied again totally. So Parasuraman, Zeithaml & Malhorta(2005) re-worked out the study about on-line service quality measure base on 2002's study and invented E-S-QUAL. After they invented preliminary measure for on-line service quality, they made up a question for customers who had purchased at amazon.com and walmart.com and reassessed this measure. And they perfected an invention of E-S-QUAL consists of 4 dimensions, 22 items of efficiency, system availability, fulfillment, privacy. Efficiency measures assess to sites and usability and others, system availability measures accurate technical function of sites and others, fulfillment measures promptness of delivering products and sufficient goods and others and privacy measures the degree of protection of data about their customers and so on. 2.2 Service Recovery Service industries tend to minimize the losses by coping with service failure promptly. This responses of service providers to service failure mean service recovery(Kelly & Davis, 1994). Bitner(1990) went on his study from customers' view about service providers' behavior for customers to recognize their satisfaction/dissatisfaction at service point. According to them, to manage service failure successfully, exact recognition of service problem, an apology, sufficient description about service failure and some tangible compensation are important. Parasuraman, Zeithaml & Malhorta(2005) approached the service recovery from how to measure, rather than how to manage, and moved to on-line market not to off-line, then invented E-RecS-QUAL which is a measuring tool about on-line service recovery. 2.3 Customer Satisfaction The definition of customer satisfaction can be divided into two points of view. First, they approached customer satisfaction from outcome of comsumer. Howard & Sheth(1969) defined satisfaction as 'a cognitive condition feeling being rewarded properly or improperly for their sacrifice.' and Westbrook & Reilly(1983) also defined customer satisfaction/dissatisfaction as 'a psychological reaction to the behavior pattern of shopping and purchasing, the display condition of retail store, outcome of purchased goods and service as well as whole market.' Second, they approached customer satisfaction from process. Engel & Blackwell(1982) defined satisfaction as 'an assessment of a consistency in chosen alternative proposal and their belief they had with them.' Tse & Wilton(1988) defined customer satisfaction as 'a customers' reaction to discordance between advance expectation and ex post facto outcome.' That is, this point of view that customer satisfaction is process is the important factor that comparing and assessing process what they expect and outcome of consumer. Unlike outcome-oriented approach, process-oriented approach has many advantages. As process-oriented approach deals with customers' whole expenditure experience, it checks up main process by measuring one by one each factor which is essential role at each step. And this approach enables us to check perceptual/psychological process formed customer satisfaction. Because of these advantages, now many studies are adopting this process-oriented approach(Yi, 1995). 2.4 Loyalty Intention Loyalty has been studied by dividing into behavioral approaches, attitudinal approaches and complex approaches(Dekimpe et al., 1997). In the early years of study, they defined loyalty focusing on behavioral concept, behavioral approaches regard customer loyalty as "a tendency to purchase periodically within a certain period of time at specific retail store." But the loyalty of behavioral approaches focuses on only outcome of customer behavior, so there are someone to point the limits that customers' decision-making situation or process were neglected(Enis & Paul, 1970; Raj, 1982; Lee, 2002). So the attitudinal approaches were suggested. The attitudinal approaches consider loyalty contains all the cognitive, emotional, voluntary factors(Oliver, 1997), define the customer loyalty as "friendly behaviors for specific retail stores." However these attitudinal approaches can explain that how the customer loyalty form and change, but cannot say positively whether it is moved to real purchasing in the future or not. This is a kind of shortcoming(Oh, 1995). 3. Research Design 3.1 Research Model Based on the objects of this study, the research model derived is
The purpose of this study was to develop and test the structural model of a contraceptive behavior in Married Korean women. A hypothesis model was constructed on the basis of the health belief model, the theory of planned behavior and extensive literature review of contraception. The model was built by seven constructs. Four exogeneous variables included in the model were consisted of the contraceptive knowledges, the perceived threats, the sexual autonomy and the communication within a couple. Four endogenous variables were consisted of the attitudes toward contraception, the perceived control, the ability to plan a intercourse and the contraceptive behaviors. Empirical data for testing the hypothetical model were collected by the self report questionnaires from 243 Korean married women. The questionnaires used in this study were developed by this researcher and their Cronbach's alpha scores were ranged from .60 to .88. The collected data were analyzed by SPSS program(ver. 8.0) for descriptive statistical analysis and LISREL program(ver. 8.12a) for covariance structural analysis. On the basis of this results, it could be suggested that contraceptive behaviors be greatly affected by the perceived threats, the communications within couple, the attitudes toward contraception and the perceived control. Finally this model would be useful for the practice, theory and research of nursing.
This research attempts to analyze the effect of printed-saving coupons distributed by major discount store on consumer purchasing intention. Those consumers having used printed-saving coupon in major discount store in Daejeon were selected as respondents. 121 copies were retreated from 150 questionnaires. For data analysis, frequency analysis for respondents' characteristics, Cronbach's alpha for reliability of analysis, and
Primarily working on SNS(Social Network Service) platform, the SNG(Social Network Game) utilizes friends and neighbors for invitation and play. Based on the value model of HCI, this paper purports to discover how functional, hedonic, social and personal values predict the continuous usage intention and satisfaction of SNG in a smartphone. Hypothesis testing through structural equation modeling shows that hedonic and functional values affect satisfaction and intention to use of SNG while social and personal values do not. This result implies that fun and easy interface are more important to the success of SNG service than social networking motivation.
The main aim of the present study is to investigate the factors that are considered affecting the adoption of Activity-Based Costing (ABC) in the autonomous public universities in Vietnam. A quantitative research was carried out. The data was collected through an online questionnaire survey between June 2020 and September 2020 addressed to the target respondents comprising 168 managers and accountants from 23 autonomous public universities in Vietnam, which participated in the resolution project No. 77/NQ-CP of the Vietnamese government on the pilot renovation of operational mechanisms of public tertiary education institutions during the period of four years, from 2014 to 2017. The findings resulted from hypothesis testing by a binary regression analysis based on the SPSS 20.0 software show that training, competition, support of top manager, and university size are the four main factors that positively affect the adoption of Activity-Based Costing (ABC) in studied universities. On the other hand, no statistically significant impact was found on two other variables, namely the variety of services provided and the usefulness of cost information factors. From the research results, discussions and policy recommendations have been presented to promote the adoption of Activity-Based Costing (ABC) in Vietnamese autonomous public universities in the coming time.
The performance of a teacher has an important role in the success of education in general. This study aims to determine the factors that affect the decline in teacher performance in one of the junior secondary schools in Indonesia. Based on the literature review, four exogenous variables were identified, namely, training, utilization of information technology, intellectual intelligence, and emotional intelligence. This study uses primary data, collected from a questionnaire distributed to respondents. The questionnaire items are measured using a Likert scale. The sample in this study were all teachers at MTS Darul Falah Sirahan, totaling 32 people. The analysis technique used in testing the hypothesis of this study is multiple regression analysis. Statistical product and service solutions are used as analysis tools. The results of this study indicate that only the variable 'utilization of information technology' has a positive and significant effect. However, the variables 'training,' 'intellectual intelligence,' and 'emotional intelligence' did not have a significant effect. This finding contradicts the literature in general. Therefore, this study recommends improving training methods, both those carried out internally by schools and by related agencies, and schools still need to optimize guidance and potential for teacher's intelligence in improving performance.
This study seeks to analyze the effect of Non-Performing Loans and Capital Adequacy Ratio on Return on Assets on ten conventional banks listed on the Indonesia Stock Exchange (BEI-IDX). This study uses secondary panel data for 2015-2019 in the form of CAR and NPL values from ten conventional banks listed on the BEI-IDX during the 2020 observation period. The research approach is quantitative descriptive with data analysis methods, namely, linear regression. The testing phase of this study includes: transform value, F-test, T-test and hypothesis test with significancy level sig < 0.05. The results of this study reveal that Non-Performing Loans had a significant negative effect (t = -2,637) (0.011 <0.0) on Return on Assets, while Capital Adequacy Ratio has no significant effect on ROA (0.760 > 0.05). R2 value is 0.128 or 12.8%. It has a significant effect on variables, calling efforts by banks, governments, and authorities monetary of related institutions to maintain the stability of finance. The reduction of Non-Performing Loan impacts on assets and capital adequacy ratio, besides, the normal NPL will control the stability of finance. If a balance is created either in the form of values or amounts of the variables, the reduction in Non-Performing Loans will be controlled.
Rapid economic growth brought material affluence and convenience, but it also has caused a negative issue, such as environmental damage. Therefore, this research holds the purpose of grasping structural influencing relationship of environmental awareness of cook, which is taking an important role in food safety among workers in hotel restaurants with eco-friendly attitude and food safety pursuit behavior. To achieve the purpose, collected materials were tested for the fidelity, organic causation and control effect, using Structural Equation Modeling for frequency analysis, confirmatory factor analysis, credibility analysis and hypothesis testing with SPSS (V23.0) and AMOS (V21.0) programs. Environmental awareness of hotel cook has causation with eco-friendly attitude, and the attitude has meaningful causation with food safety pursuit behavior. That is, it proved that cooks are taking care of their job carefully from the pre-cooking stage while most of people ignore the storing stage. The result shows not only hotel's own training session, cook's level of consciousness on the food safety and they are working with high sense of responsibility. The limitation of this research is that it only conducted with cooks of deluxe hotels in Busan, and it could not include various variables about environmental awareness. Therefore, it is expected that the lacking contents to be dealt by a follow-up study.
Objectives : This study aimed to identify the perception of quality improvement in health care and operational performance after the implementation of the Healthcare Accreditation. Methods : Data were collected from 5 hospitals that have experienced the 2th Healthcare Accreditation in Busan, South Korea. A Likert 5-point scale was used to measure the research variables and a structured questionnaire was used. Finally, 206 valid cases were analyzed using SPSS win 18.0. For hypothesis testing, hierarchical multiple regression analysis were performed. Results : The perception of quality improvement in health care after the implementation of the Healthcare Accreditation was higher than the operational performance. In the customer orientation and job performance, the perception of quality improvement in health care and operational performance had a significant influence. Conclusions : It is necessary to use the Healthcare Accreditation as a virtuous cycle of management that can ensure enforcement of workplace regulations and improve the members'ability to provide high quality medical services.
. 3.2 Hypotheses 3.2.1 The Hypothesis of On-line Service Quality and Overall Service Quality shows, Step 1 and Step 2 are significant, and mediation variable has a significant effect on dependent variables and so does independent variables at Step 3, too. And there needs to prove the partial mediation effect, independent variable's estimate ability at Step 3(Standardized coefficient
shows, Step 1 and Step 2 are significant, and mediation variable has a significant effect on dependent variables and so does independent variables at Step 3, too. And there needs to prove the partial mediation effect, independent variable's estimate ability at Step 3(Standardized coefficient
A Structural Equation Model Explaining Contraception Behaviors of Married Korean Women
(기혼여성의 피임행위에 관한 설명모형)
Effects of Printed-Saving Coupon on Purchasing Intention of Consumer Behavior in Major Discount Store
(대형 할인 마트의 인쇄 쿠폰 발행이 소비자 구매 의도에 미치는 영향)
Factors Affecting the Continuous Use Intention of Smartphone Social Network Games : With a Focus on the Value Model
(스마트폰 소셜 네트워크 게임의 지속 사용의도 영향 요인 : 가치모형을 중심으로)
Factors Affecting Activity-Based Costing Adoption in Autonomous Public Universities in Vietnam
The Effect of Training, Information Technology, Intellectual and Emotional Intelligence on Teacher's Performance
Effect of CAR and NPL on ROA: Empirical Study in Indonesia Banks
Effect of Cook's Environmental Awareness and Eco-friendly Attitude on Food Safety Pursuit Behavior
(조리사의 환경의식과 친환경태도가 식품안전추구행동에 미치는 영향)
The Effects of the Perception of Quality Improvement in Health Care and Operational Performance on Customer Orientation and Job Performance after Healthcare Accreditation
(의료기관인증제 시행 후 의료 질 향상과 운영성과에 대한 인식이 고객지향성 및 직무성과에 미치는 영향)
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