• Title/Summary/Keyword: Model Validity

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Steady Shear Flow Properties of Aqueous Poly(Ethylene Oxide) Solutions (폴리에틸렌옥사이드 수용액의 정상유동 특성)

  • Song, Ki-Won;Kim, Tae-Hoon;Chang, Gap-Shik;An, Seung-Kook;Lee, Jang-Oo;Lee, Chi-Ho
    • Journal of Pharmaceutical Investigation
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    • v.29 no.3
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    • pp.193-203
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    • 1999
  • In order to investigate systematically the steady shear flow properties of aqueous po1y(ethylene oxide) (PEO) solutions having various molecular weights and concentrations, the steady flow viscosity has been measured with a Rheometrics Fluids Spectrometer (RFS II) over a wide range of shear rates. The effects of shear rate, concentration, and molecular weight on the steady shear flow properties were reported in detail from the experimentally measured data, and then the results were interpreted using the concept of a material characteristic time. In addition, some flow models describing the non-Newtonian behavior (shear-thinning characteristics) of polymeric liquids were employed to make a quantitative evaluation of the steady flow behavior, and the applicability of these models was examined by calculating the various material parameters. Main results obtained from this study can be summarized as follows: (1) At low shear rates, aqueous PEO solutions show a Newtonian viscous behavior which is independent of shear rate. At shear rate region higher than a critical shear rate, however, they exhibit a shear-thinning behavior, demonstrating a decrease in steady flow viscosity with increasing shear rate. (2) As an increase in concentration and/or molecular weight, the zero-shear viscosity is increased while the Newtonian viscous region becomes narrower. Moreover, the critical shear rate at which the transition from the Newtonian to shear-thinning behavior occurs is decreased, and the shear-thinning nature becomes more remarkable. (3) Aqueous PEO solutions show a Newtonian viscous behavior at shear rate range lower than the inverse value of a characteristic time $1/{\lambda}_E$, while they exhibit a shear-thinning behavior at shear rate range higher than $1/{\lambda}_E$. For aqueous PEO solutions having a broad molecular weight distribution, the inverse value of a characteristic time is not quantitatively equivalent to the critical shear rate, but the power-law relationship holds between the two quantities. (4) The Cross, Carreau, and Carreau-Yasuda models are all applicable to describe the steady flow behavior of aqueous PEO solutions. Among these models, the Carreau-Yasuda model has the best validity.

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Evaluation of Deformation Characteristics and Vulnerable Parts according to Loading on Compound Behavior Connector (복합거동연결체의 하중재하에 따른 변형 특성 및 취약부위 산정)

  • Kim, Ki-Sung;Kim, Dong-wook;Ahn, Jun-hyuk
    • Journal of the Society of Disaster Information
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    • v.15 no.4
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    • pp.524-530
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    • 2019
  • Purpose: In this paper, we construct a detailed three-dimensional interface element using a three-dimensional analysis program, and evaluate the composite behavior stability of the connector by applying physical properties such as the characteristics of general members and those of reinforced members Method: The analytical model uses solid elements, including non-linear material behavior, to complete the modeling of beam structures, circular flanges, bolting systems, etc. to the same dimensions as the design drawing, with each member assembled into one composite behavior linkage. In order to more effectively control the uniformity and mesh generation of other element type contact surfaces, the partitioning was performed. Modeled with 50 carbon steel materials. Results: It shows the displacement, deformation, and stress state of each load stage by the contact adjoining part, load loading part, fixed end part, and vulnerable anticipated part by member, and after displacement, deformation, The effect of the stress distribution was verified and the validity of the design was verified. Conclusion: Therefore, if the design support of the micro pile is determined based on this result, it is possible to identify the Vulnerable Parts of the composite behavior connector and the degree of reinforcement.

A Study on the Factors Affecting the Use and Satisfaction of Internet Ticketing Systems (인터넷 티켓팅 시스템의 사용과 만족에 영향을 미치는 요인)

  • Woo, Sung-Hwa;Kim, Kyung-Kyu;Chang, Hang-Bae;Shin, Ho-Kyoung
    • Asia pacific journal of information systems
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    • v.17 no.3
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    • pp.1-24
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    • 2007
  • With the development of information technology (IT), various information systems (IS) such as Web-based systems and mobile systems have appeared utilizing different technologies. However, recent studies on IS use and user satisfaction rarely account for technological differences among IS and environmental characteristics where IS are intended to be used. The purpose of this research is to investigate the determinants of the use of Web-based ticketing systems for cultural activities and to empirically validate their relationships. Environmental psychology suggests that human beings respond to external stimuli from environments with their emotions, and their emotional states influence human actions, e.g., IS use in this research. Applying environmental psychology to the use of Web-based systems in the culture and entertainment industry, we propose that web site characteristics first influence a user's internal state of mind (i.e., flow) and then the flow state influences the IS use. Studies related to the state of flow collectively affirm the key role played by the flow construct in shaping individual attitudes and behaviors toward IS. Users' flow states are captured by their shopping enjoyment, perceived behavioral control, and the level of concentration on the IS use. Referring to social presence theory, we have included such web site characteristics as content quality, context of web site, and community quality. In our research model, a second order construct is utilized to represent web site quality, because flow theory suggests that holistic experiences with web-based systems (rather than individual characteristics of the web site) are important in explaining the IS use. Further, we have included trust as another important factor influencing the IS use since business transactions on the web encompass higher uncertainty comparing to offline transactions. In order to test our hypotheses, we have conducted an online survey which results in 1,141 valid responses in the final sample. The data were collected from respondents who have experiences in Internet ticketing systems. Although it was a convenient sample, the sample represents a wide variety of user demographics. Validity and reliability of the research instrument were tested and research hypotheses were examined using PLS Graph 3.0. The results indicate that web site characteristics significantly influence the level of user concentration, user's enjoyment in shopping, and perceived behavioral control. Further, the use of Internet ticketing systems is influenced by users' flow states and trust in the web channel. User satisfaction is turned out to be affected by the use of Internet ticketing systems. Unlike extant research on the relationship between web site characteristics and its use, our study has found that, in the culture and entertainment industry, the impact of web site characteristics on IS use is mediated by a user's flow state. This finding has a practical implication that web site design should include as many features that enhance shopping enjoyment and concentration. Other practical implications of these findings and future research implications are also discussed.

Production of Reactive Diluent for Epoxy Resin with High Chemical Resistance from Natural Oil : Optimization Using CCD-RSM (천연오일로부터 내화학성이 향상된 에폭시계 수지용 반응성 희석제의 제조 : CCD-RSM을 이용한 최적화)

  • Yoo, Bong-Ho;Jang, Hyun Sik;Lee, Seung Bum
    • Applied Chemistry for Engineering
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    • v.31 no.2
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    • pp.147-152
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    • 2020
  • In this study, we dedicated to optimize the process for a reactive diluent for epoxy resin of improved chemical resistance by using cardanol, a component of natural oil of cashew nut shell liquid (CNSL). The central composite design (CCD) model of response surface methodology (RSM) was used for the optimization. The quantitative factors for CCD-RSM were the cardanol/ECH mole ratio, reaction time, and reaction temperature. The yield, epoxy equivalent, and viscosity were selected as response values. Basic experiments were performed to design the reaction surface analysis. The ranges of quantitative factors were determined as 2~4, 4~8 h, and 100~140 ℃ for the cardanol/ECH reaction mole ratio, reaction time, and reaction temperature, respectively. From the result of CCD-RSM, the optimum conditions were determined as 3.33, 6.18 h, and 120 ℃ for the cardanol/ECH reaction mole ratio, reaction time, and reaction temperature, respectively. At these conditions, the yield, epoxy equivalence, and viscosity were estimated as 100%, 429.89 g/eq., and 41.65 cP, respectively. In addition, the experimental results show that the error rate was less than 0.3%, demonstrating the validity of optimization.

The effects of the value of performing art on attitude and customer satisfaction (공연예술에 대한 가치가 태도와 고객만족도에 미치는 영향에 관한 연구)

  • Koo, Eun-Ja;Park, Su-Jin;Ahn, Sung-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.543-551
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    • 2016
  • Recently, the cultural industry has become an attractive industry which is having a dramatic effect with the rise of Hallyu offering many possibilities for development. Specially, the marketing techniques employed by the performing arts industry started to change to respond to consumer tastes and demands like other commodity markets, as the popular performing arts industry began to receive attention as a promising industry. It is important to identify the behavior of consumers in order to actively deal with the demands and tastes of consumers that are becoming increasingly diverse and individualized. The performing arts market needs to recognize the importance of its audience and to apply appropriate marketing techniques. This study attempted to empirically identify the value of performing arts perceived by the audience and to investigate the influence of the relationship between the perceived value, attitude formation and satisfaction with performing arts. In order to examine the influence of the value of performing arts on attitude and customer satisfaction, a reliability analysis and factor analysis were conducted to investigate the dependability and validity of the measured variables. In order to achieve the study's intended purpose, the structural equation model (SEM) was utilized as the core analysis method. As a result, it was found that the perceived value and attitude towards performing arts have a positive effect on customer satisfaction. The results of this study are expected to be used as the basic data for organizations that plan performances to improve their marketing and promotion around the audience and for more specific and detailed research in the future.

Efficient Multiple Joins using the Synchronization of Page Execution Time in Limited Processors Environments (한정된 프로세서 환경에서 체이지 실행시간 동기화를 이용한 효율적인 다중 결합)

  • Lee, Kyu-Ock;Weon, Young-Sun;Hong, Man-Pyo
    • Journal of KIISE:Databases
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    • v.28 no.4
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    • pp.732-741
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    • 2001
  • In the relational database systems the join operation is one of the most time-consuming query operations. Many parallel join algorithms have been developed 개 reduce the execution time Multiple hash join algorithm using allocation tree is one of the most efficient ones. However, it may have some delay on the processing each node of allocation tree, which is occurred in tuple-probing phase by the difference between one page reading time of outer relation and the processing time of already read one. This delay problem was solved by using the concept of synchronization of page execution time with we had proposed In this paper the effects of the performance improvements in each node of the allocation tree are extended to the whole allocation tree and the performance evaluation about that is processed. In addition we propose an efficient algorithm for multiple hash joins in limited number of processor environments according to the relationship between the number of input relations in the allocation tree and the number of processors allocated to the tree. Finally. we analyze the performance by building the analytical cost model and verify the validity of it by various performance comparison with previous method.

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Study on Effects of Person-Job Fit of High Touching Service Employees on Emotional Intelligence and Job Satisfaction (서비스 종사자의 개인-직무적합성이 감정지능 및 직무만족에 미치는 영향에 관한 연구)

  • Kim, Yu-Kyung
    • Journal of Distribution Science
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    • v.14 no.4
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    • pp.81-92
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    • 2016
  • Purpose - In recent years, management scholars have expressed growing interest in the concept of person-Job fit because of having many benefits for employees' attitudes and behaviors. The related research is needed to determine what specific types of fit are related to each other, and to get important individual outcomes. Person-job fit of employees in service organization plays an important role in company as well as person in service industry. Person-job fit, representing the consistency between person (service provider) and job (service provided to the customers), gives significant and positive effects on the attitude and behavior of service provider. On the basis of the study background, the purpose of this study is as follows. First, we would like to examine the effects of person-job fit of service provider on their emotional intelligence. Emotional intelligence is divided into four sub-factors such as self-understanding, understanding others, emotional utilization, and emotional regulation. Second, we would like to identify the relationships between job satisfaction and sub-factors such as self-understanding, understanding others, emotional utilization, and emotional regulation. Research design, data, and methodology - We performed structural equation model using Spss 18.0 and Amos 20.0 in order to verify the hypotheses. Subjects were golf service assistants who were high-touching service with high degree in interaction and long contact time with customers. 178 out of the total 200 surveys were used in evaluation from helpers of golf service working as full-time service provider after selecting two locations of golf course located near Busan. From the evaluation of reliability and validity with variables used in this research, they satisfied and confirmed certain standard. Results - The results are as follows. First, as the results of identifying the relationships between person-job fit and emotional intelligence of service provider, person-job fit did not have positive and significant effect on self-understanding. On the other hand, it affected positively and significantly other factors in emotional intelligence such as emotion to others, emotional utilization, and emotional regulation. Second, as the results of identifying the relationship between emotional intelligence and job satisfaction, sub-factors in emotional intelligence such as emotion to others, emotional utilization, and emotional regulation except self-emotion affected significantly and positively job satisfaction. However, self-emotion did not have significant and positive effects on job satisfaction. Conclusion - These results will be valuable and used for service providers. In addition, many service providers will recognize that person-job fit is very important to get a job. This research has a purpose on the assumption that appropriateness between individual and task in service industry shall act as major influence in emotional intelligence of service provider. Recognitive ability of service provider is also very important per characteristics of service, but emotional intelligence that interacts and connected directly with most customers can be a very meaningful factor as well. Emotional intelligence allows people to recognize, understand, and empathize the emotion of customers shall be a positive reinforcement for customers to evaluate the service ultimately.

Effects of the Support and Control of Franchisors on Franchisees' Satisfaction and Response Strategies (프랜차이즈 가맹본부의 지원, 통제가 가맹점사업자의 만족 및 반응전략에 미치는 영향)

  • Kwon, Yong-Deok;Yu, Jong-Pil
    • Journal of Distribution Science
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    • v.12 no.8
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    • pp.43-54
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    • 2014
  • Purpose - This study was based on a theoretical consideration of the structural relationship between the support and control of the franchisor and the satisfaction and strategic response (voice, loyalty, exit, neglect) of the franchisee. First, based on the preceding research, this study systematically organized the type of support and control of the franchisor. Second, the study examined the effects of a franchisor's support and control on the expectancy disconfirmation between affiliated franchisees' expectations before a franchise agreement and performance after operating an affiliated store. Third, the study looked into the effects of expectancy disconfirmation relating to a franchisor's support and control on an affiliated franchisees' general satisfaction. Fourth, this study examined the influence of the general satisfaction of a franchisee on affiliated franchisees' response strategies. Research design, data, and methodology - In this study, the population comprised the nation's franchisors, and the sample comprised franchisees conducting business in Seoul and Gyeonggi-do. A self-administered questionnaire was used; the author and examiner explained the study's parameters to the interviewees in advance, to lessen the rate of rejection of the answers and to maintain reliability. The author distributed 350 copies of the questionnaire and collected 327 copies (93.4%). The author removed 54 copies of the sample, as these copies belonged to franchisees that were not registered by the Fair Trade Commission and/or were thought to have either defects or inadequate answers. The author selected an effective sample of 273 copies to enter data and to do the statistical analysis. Results - Both a reliability analysis and a confirmatory factor analysis were performed to measure reliability and validity, and a structural equation model was used to conduct the hypothesis test and investigate the models. The hypothesis was tested (Table 5). The models had a suitable fit, for instance, χ2 = 447.663(df = 212, p = .000), χ2/df = 2.112, GFI = .881, AGFI = .858, RMR = .083, RMSEA = .067, NFI = .932, and CFI = .961. The hypothesis test results were as follows. Hypothesis 1 was accepted (C.R. = -2.339, p = .019). Hypothesis 2 was accepted (C.R. = 15.213, p = .000). Hypothesis 3 was accepted (C.R. = -2.631, p = .006). Hypothesis 4 was accepted (C.R. = 16.271, p = .000). Hypothesis 5 was accepted (C.R. = 2.391, p = .017). Hypothesis 6 was accepted (C.R. = 5.777, p = .000). Hypothesis 7 was accepted (C.R. = 17.153, p = .000). Hypothesis 8 was accepted (C.R. = 24.746, p = .000). Hypothesis 9 was accepted (C.R. = -10.150, p = .000). Hypothesis 10 was accepted (C.R. = -12.124, p = .000). Conclusions - The research results showed that expectations for a franchisor's support and control had a significant influence on expectation disconfirmation in a negative way, whereas the performance of support and control were found to have a significant influence on expectation disconfirmation in a positive way. In addition, the expectation disconfirmation of support and control was found to have a significant influence on satisfaction of franchisees in a positive way. Generally, regarding the research on control, control is found to have a negative influence on the satisfaction of franchisees, but this study proves that control is found to affect it in a positive way through conformity.

The study on the school resilience of grandparent-grandchildren family adolescent through mediation effect of protective factor (보호요인의 매개효과를 통한 조손가족 청소년의 학교 적응유연성에 관한 연구)

  • Song, Yoo-Mee;Lee, Yun-Hyung
    • Korean Journal of Social Welfare Studies
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    • v.40 no.3
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    • pp.41-68
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    • 2009
  • Grandparent-grandchildren family adolescents(GGFAs) need to be well discussed because they tend to be more influenced by the negative surroundings than ordinary family adolescents. Over the past few years, several studies have been made on the correlation between the risk factor, the protective factor and the school resilience of GGFAs, but these studies have the limit to explain the only correlation between the one factor and the school resilience. So the purpose of this study was to examine not only the direct effect between the risk factor and the protective factor, but also the parametric path and effect that the one factor has influence on the correlation between the another factor and the school resilience of GGFAs. We investigated the 328 GGFAs in Korea, and the analytic method used was the Structural Equation Modeling(SEM). The followings are the results of this paper. It was found that the model adaptability had a considerable validity by inspecting the SEM, which showed not only the direct effect between the risk factor, protective factor and the school resilience of GGFAs, but also the mediation effect by the protective factor. The risk factors - the indifference of teacher, the negative attachment relationship, melancholy, uneasiness etc - had a negative influence on the school resilience of GGFAs. The protective factors - the supporss etteacher, self-esteem etc - had a positive influence on the school resilience of GGFAs. The protective factors were found to reduce the negative influence on the school resilience of GGFAs.

Development of Convergence Education Program Based on 3D Panorama Virtual Fieldwork Courses on Water Spider in Eundaeri (은대리 물거미 서식지의 3D 파노라마 가상야외학습장 융합교육 프로그램 개발)

  • Yoon, Ma-Byong
    • The Journal of the Korea Contents Association
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    • v.19 no.10
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    • pp.607-619
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    • 2019
  • This study used Natural Monument water spiders and their habitats as educational contents, so those students could have a scientific literacy and the beautiful memories of Eundaeri's marshes through developing a virtual fieldwork courses (VFC) and observing the ecology of water spiders. In order to develop the program, the 2015 revised national curriculum and its textbooks were analyzed. In accordance with the STEAM model, we developed teaching-learning materials for 7 classes. Students produced 3D panorama virtual fieldwork courses (PVFC) about water spider by team-based cooperative learning, enabling them to emotionally experience the meaning and value of water spiders. A panel of six education experts verified the validity of the program and found it to be fairly valid at 4.24 (CVI = .88) on the 5-point Likert scale. In order to confirm the suitability of the program, students in the middle school science clubs participated in pilot testing camp. Their average classes satisfaction was 4.24 and students were very satisfied with the usefulness of the program, the fresh learning contents, and the suitability of the convergence education class. This study could contribute to convergence education related to ecology and virtual reality for adolescents.