• Journal of Life Science
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• v.21 no.12
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• pp.1678-1688
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• 2011

The apoptogenic effect of p-coumaric acid, a phenolic acid found in various edible plants, on human acute leukemia Jurkat T cells was investigated. Exposure of Jurkat T cells to p-coumaric acid (50-$150{\mu}M$) caused cytotoxicity and TdT-mediated dUTP nick-end labeling (TUNEL)-positive apoptotic DNA fragmentation along with Bak activation, ${\Delta}{\psi}m$ loss, activation of caspase-9, -3, -7, and -8, and PARP degradation in a dose-dependent manner. However,these apoptotic events were completely abrogated in Jurkat T cells overexpressing Bcl-2.Under these conditions, necrosis was not accompanied. Pretreatment of the cells with the pan-caspase inhibitor (z-VAD-fmk) could prevent p-coumaric acid-induced sub-$G_1$ peak representing apoptotic cells, whereas it failed to block ${\Delta}{\psi}m$ loss, indicating that the activation of caspase cascade was prerequisite for p-coumaric acid-induced apoptosis as a downstream event of ${\Delta}{\psi}m$ loss. FADD- and caspase-8-positive wild-type Jurkat T cell clone A3, FADD-deficient Jurkat T cell clone I2.1, and caspase-8-deficient Jurkat T cell clone I9.2 exhibited similar susceptibilities to the cytotoxicity of p-coumaric acid, excluding an involvement of Fas/FasL system in triggering the apoptosis. The apoptogenic activity of p-coumaric acid is more potent in malignant Jurkat T cells than in normal human peripheral T cells. Together, these results demonstrated that p-coumaric acid-induced apoptogenic activity in Jurkat T cellswas mediated by Bak activation, ${\Delta}{\psi}m$ loss, and subsequent activation of multiple caspases such as caspase-9, -3, -7, and-8, and PARP degradation, which could be regulated by anti-apoptotic protein Bcl-2.

• The Korean Journal of Ecology
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• v.26 no.3
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• pp.143-150
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• 2003

Korea has plentiful precipitation but rainfall events concentrate on several months of rainy season in her weather condition. Korea, therefore, experiences drought for a given period every year. Moreover the soil has usually low water holding capacity, as it is composed coarse particles originated from the granite. Response of several oaks and the Korean red pine (Pinus densiflora) on water stress showed that water budget was significant factor determining vegetation distribution. In addition, dehydration level due to cold resistance mechanism of several evergreen plants during the winter season was closely related to their distribution in natural condition. Experimental result under water stress showed that the Korean red pine was very tolerant to desiccation but the seedlings showed high mortality during the dry season. The mortality tended to proportionate to soil moisture content of each site. A comparison between soil moisture content during June when it is severe dry season and moisture content of the culture soil when the pine seedlings reached the permanent wilting point due to water withheld proved that high mortality during the dry season was due to water deficit. Water potential of sample plants measured during the exposure experiment to the air pollutant showed a probability that water related factors would dominate the occurrence of visible damage and the tolerance level of sample plants. In both field survey and laboratory experiment, plants exposed to air pollution showed more rapid transpiration than those grown in the unpolluted condition. The result would due to injury of leaf surface by air pollutants. Aluminum (Al/sup 3+/) increased in the acid soil not only inhibits root growth but also leads to abnormal distribution of root system and thereby caused water stress. The water stresses due to air pollution and soil acidification showed a possibility that they play dominating roles in inducing forest decline additionally to the existing water deficit due to weather and soil conditions in Korea. Sludge, which can contribute to improve field capacity, as it is almost composed of organic matter, showed an effect ameliorating the retarded growth of plant in the acidified soil. The effect was not less than that of dolomite known in widely as such a soil ameliorator. Litter extract contributed also to mitigate the water stress due to toxic Al/sup 3+/. We prepared a model showing the potential interaction of multiple stresses, which can cause forest decline in Korea by synthesizing those results. Furthermore, we suggested restoration plans, which can mitigate such forest decline in terms of soil amelioration and vegetation restoration.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.101-110
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• 2014

This study analyzes the validity of the type classification of the type and design changes of apartment landscaping planting construction design changes that were completed in the private sector, efficiently manages the design changes that are displayed over landscaping planting work in general in the future, and performs research by placing the object underlying the presentation. The results are as follows. First, the percentage that occurred in the planting construction of design changes that have occurred in the apartment landscaping construction was carried out in the private sector and accounted for 61.8%. This indicates that part of the planting is a major design change. Second, as the cause of such a design change to be those associated with the field conditions such as lack of main construction period. In particular, due to a change in oral, appeared 7-48 times design changes of one review design change approval is complex, design changes of planting construction had shown a feature that occurs in multiple simultaneous. Third, the 7 types of Design Changes in planting design were delineated as 'design changes for consideration of the user', 'design changes for image improvement', 'design changes for ease of maintenance', 'design changes due to the mismatch of design statement', 'design changes due to the relationship with the engineering species of other', 'design changes due to lack of field study', and 'design changes due to the consideration of feasibility.' Fourth, 'design changes for consideration of the user' and 'design changes for image improvement' were found in more than half of the frequency of the overall changes. This differed from the results shown in public corporations. Fifth, if planting construction design change process, private companies, it was found that is showing the approval of the practice after the previous construction of the construction cost savings due to construction time. However, in the case of a public corporation, these exhibited a different aspect from the private sector and show a design change procedure that reflects the changes after the design change events in the field have occurred. The above results, the type of landscaping works in planting design change of public enterprises, regardless of the private sector, is the same in the seven types, the main reason of and procedures for design changes, indicating that there are other respects. In design change, it may be desirable to apply becomes liquidity rationality and efficiency of the dimension, depending on the nature of the landscape construction.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.36-45
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• 2012

Education on the environment and plants offered by arboretum for today's people not only contribute to foster a better natural environment in urban region but also provide visitors with decent refreshment environment and beyond. In the study, the author undertook the observation on usage behavior and satisfaction model of arboretum visitors expect and investigated the facilities and programs to be offered by arboretum in order to propose the opinion regarding the service. For observation size of variables in a multiple regression analysis of variables is influencing satisfaction rankings walks the line of flow, the educational effect on the environment, cleanliness of the facility, visits pay, natural beauty, diversity of trees, accessibility and friendliness of staff, expansion of facilities in the arboretum and appeared as a complement. In case of visitor attribute, the residents living near the facility showed the highest visit frequency of more than 5 times, especially as part of taking a walk. This proves that the visit to arboretum is considered as part of everyday life, and thus a new program and walk path as well as movement route are needed to be developed for the visitors. In the question relating to the facilities and operation programs in Daegu Arboretum, particularly the requests by visitors, they responded that the establishment of cultural event, beautiful natural scenery, refreshment and convenience facilities is the most critical issue. In addition, the management on withered trees and bare lands is an urgent issue as well. In this sense, the Operation and Management Strategies based upon the visitor behaviors and model of satisfaction are needed to deal with the adoption of diverse events and festivals joined by local residents, ombudsman program, environmental program development for students and teachers within the region, negligent bare lands and withered tree replacement, and cafeteria facility improvement and supplement as well as the bench marking of other facilities than arboretums located in other regions. These items are thought to be sufficiently dealt with by Daegu Arboretum having no more external resources. It is recognized that the visitor satisfaction begins from a minor thing, and a small difference determines a great satisfaction, and thus the software approach rather than hardware one is in need.

• Journal of Intelligence and Information Systems
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• v.24 no.4
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• pp.51-66
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• 2018

As AI (Artificial Intelligence) technologies have been swiftly evolved, a lot of products and services are under development in various fields for better users' experience. On this technology advance, negative effects of AI technologies also have been discussed actively while there exists positive expectation on them at the same time. For instance, many social issues such as trolley dilemma and system security issues are being debated, whereas autonomous vehicles based on artificial intelligence have had attention in terms of stability increase. Therefore, it needs to check and analyse major social issues on artificial intelligence for their development and societal acceptance. In this paper, multi-categorical sentiment analysis is conducted over online public opinion on artificial intelligence after identifying the trending topics related to artificial intelligence for two years from January 2016 to December 2017, which include the event, match between Lee Sedol and AlphaGo. Using the largest web portal in South Korea, online news, news headlines and news comments were crawled. Considering the importance of trending topics, online public opinion was analysed into seven multiple sentimental categories comprised of anger, dislike, fear, happiness, neutrality, sadness, and surprise by topics, not only two simple positive or negative sentiment. As a result, it was found that the top sentiment is "happiness" in most events and yet sentiments on each keyword are different. In addition, when the research period was divided into four periods, the first half of 2016, the second half of the year, the first half of 2017, and the second half of the year, it is confirmed that the sentiment of 'anger' decreases as goes by time. Based on the results of this analysis, it is possible to grasp various topics and trends currently discussed on artificial intelligence, and it can be used to prepare countermeasures. We hope that we can improve to measure public opinion more precisely in the future by integrating empathy level of news comments.

• 한국노년학
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• v.30 no.4
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• pp.1293-1309
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• 2010

This study is aimed to evaluate the effects of community-based prehabilitation program developed to prevent functional decline in the frail elderly and to provide a basis to practically operate this program in the public health care service. From March to August 2009, 110 frail elderly people were recruited among the registered participants of the home visit program in Korea to perform a prospective randomized community trial. We randomly assigned these people into two groups. One group (n=50) participated in the visiting prehabilitation program for 3 months focusing on improving their muscle strength of upper and lower limbs, walking ability, and balancing. The other group (n=60) underwent our visiting fall prevention program for control. To assess the effectiveness of prehabilitation program, physical functioning (PF) and short physical performance battery (SPPB) were measured for the primary outcomes and also some other indicators: exercise performance, nutritional status, emotional functioning, experience of admission, and events of fall. As a result, significant improvements of geriatric functional status were noticed among the participants. After 3 months, PF increased by 1.3 ± 3.8 points in prehabilitation group and decreased by 1.1 ± 5.4 points in controls (p=.020). SPPB improved by 2.4 ± 2.0 points in prehabilitation group and increased only 0.3 ± 1.5 points in controls (p<.001). Significant effects were also shown in their exercise performance tests and emotional status, the number of multiple falls, and the experience of functional decline after the fall (p .002-.038). Visiting prehabilitation program is safe and effective program for frail older adults. Thus, it is strongly recommended to universally adopt this program to prevent functional decline in the frail elderly.

• Journal of Korea Water Resources Association
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• v.57 no.5
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• pp.333-346
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• 2024

High-resolution medium-range streamflow prediction is crucial for sustainable water quality and aquatic ecosystem management. For reliable medium-range streamflow predictions, it is necessary to understand the characteristics of forcings and to effectively utilize weather forecast data with low spatio-temporal resolutions. In this study, we presented a comparative analysis of medium-range streamflow predictions using the distributed hydrological model, WRF-Hydro, and the numerical weather forecast Global Data Assimilation and Prediction System (GDAPS) in the Geumho River basin, Korea. Multiple forcings, ground observations (AWS&ASOS), numerical weather forecast (GDAPS), and Global Land Data Assimilation System (GLDAS), were ingested to investigate the performance of streamflow predictions with highresolution WRF-Hydro configuration. In terms of the mean areal accumulated rainfall, GDAPS was overestimated by 36% to 234%, and GLDAS reanalysis data were overestimated by 80% to 153% compared to AWS&ASOS. The performance of streamflow predictions using AWS&ASOS resulted in KGE and NSE values of 0.6 or higher at the Kangchang station. Meanwhile, GDAPS-based streamflow predictions showed high variability, with KGE values ranging from 0.871 to -0.131 depending on the rainfall events. Although the peak flow error of GDAPS was larger or similar to that of GLDAS, the peak flow timing error of GDAPS was smaller than that of GLDAS. The average timing errors of AWS&ASOS, GDAPS, and GLDAS were 3.7 hours, 8.4 hours, and 70.1 hours, respectively. Medium-range streamflow predictions using GDAPS and high-resolution WRF-Hydro may provide useful information for water resources management especially in terms of occurrence and timing of peak flow albeit high uncertainty in flood magnitude.

• Journal of Intelligence and Information Systems
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• v.22 no.1
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• pp.107-118
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• 2016

The advent of 5G mobile communications, which is expected in 2020, will provide many services such as Internet of Things (IoT) and vehicle-to-infra/vehicle/nomadic (V2X) communication. There are many requirements to realizing these services: reduced latency, high data rate and reliability, and real-time service. In particular, a high level of reliability and delay sensitivity with an increased data rate are very important for M2M, IoT, and Factory 4.0. Around the world, 5G standardization organizations have considered these services and grouped them to finally derive the technical requirements and service scenarios. The first scenario is broadcast services that use a high data rate for multiple cases of sporting events or emergencies. The second scenario is as support for e-Health, car reliability, etc.; the third scenario is related to VR games with delay sensitivity and real-time techniques. Recently, these groups have been forming agreements on the requirements for such scenarios and the target level. Various techniques are being studied to satisfy such requirements and are being discussed in the context of software-defined networking (SDN) as the next-generation network architecture. SDN is being used to standardize ONF and basically refers to a structure that separates signals for the control plane from the packets for the data plane. One of the best examples for low latency and high reliability is an intelligent traffic system (ITS) using V2X. Because a car passes a small cell of the 5G network very rapidly, the messages to be delivered in the event of an emergency have to be transported in a very short time. This is a typical example requiring high delay sensitivity. 5G has to support a high reliability and delay sensitivity requirements for V2X in the field of traffic control. For these reasons, V2X is a major application of critical delay. V2X (vehicle-to-infra/vehicle/nomadic) represents all types of communication methods applicable to road and vehicles. It refers to a connected or networked vehicle. V2X can be divided into three kinds of communications. First is the communication between a vehicle and infrastructure (vehicle-to-infrastructure; V2I). Second is the communication between a vehicle and another vehicle (vehicle-to-vehicle; V2V). Third is the communication between a vehicle and mobile equipment (vehicle-to-nomadic devices; V2N). This will be added in the future in various fields. Because the SDN structure is under consideration as the next-generation network architecture, the SDN architecture is significant. However, the centralized architecture of SDN can be considered as an unfavorable structure for delay-sensitive services because a centralized architecture is needed to communicate with many nodes and provide processing power. Therefore, in the case of emergency V2X communications, delay-related control functions require a tree supporting structure. For such a scenario, the architecture of the network processing the vehicle information is a major variable affecting delay. Because it is difficult to meet the desired level of delay sensitivity with a typical fully centralized SDN structure, research on the optimal size of an SDN for processing information is needed. This study examined the SDN architecture considering the V2X emergency delay requirements of a 5G network in the worst-case scenario and performed a system-level simulation on the speed of the car, radius, and cell tier to derive a range of cells for information transfer in SDN network. In the simulation, because 5G provides a sufficiently high data rate, the information for neighboring vehicle support to the car was assumed to be without errors. Furthermore, the 5G small cell was assumed to have a cell radius of 50-100 m, and the maximum speed of the vehicle was considered to be 30-200 km/h in order to examine the network architecture to minimize the delay.

• Journal of Intelligence and Information Systems
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• v.18 no.3
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• pp.185-202
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• 2012

.Since the value of information has been realized in the information society, the usage and collection of information has become important. A facial expression that contains thousands of information as an artistic painting can be described in thousands of words. Followed by the idea, there has recently been a number of attempts to provide customers and companies with an intelligent service, which enables the perception of human emotions through one's facial expressions. For example, MIT Media Lab, the leading organization in this research area, has developed the human emotion prediction model, and has applied their studies to the commercial business. In the academic area, a number of the conventional methods such as Multiple Regression Analysis (MRA) or Artificial Neural Networks (ANN) have been applied to predict human emotion in prior studies. However, MRA is generally criticized because of its low prediction accuracy. This is inevitable since MRA can only explain the linear relationship between the dependent variables and the independent variable. To mitigate the limitations of MRA, some studies like Jung and Kim (2012) have used ANN as the alternative, and they reported that ANN generated more accurate prediction than the statistical methods like MRA. However, it has also been criticized due to over fitting and the difficulty of the network design (e.g. setting the number of the layers and the number of the nodes in the hidden layers). Under this background, we propose a novel model using Support Vector Regression (SVR) in order to increase the prediction accuracy. SVR is an extensive version of Support Vector Machine (SVM) designated to solve the regression problems. The model produced by SVR only depends on a subset of the training data, because the cost function for building the model ignores any training data that is close (within a threshold ${\varepsilon}$) to the model prediction. Using SVR, we tried to build a model that can measure the level of arousal and valence from the facial features. To validate the usefulness of the proposed model, we collected the data of facial reactions when providing appropriate visual stimulating contents, and extracted the features from the data. Next, the steps of the preprocessing were taken to choose statistically significant variables. In total, 297 cases were used for the experiment. As the comparative models, we also applied MRA and ANN to the same data set. For SVR, we adopted '${\varepsilon}$-insensitive loss function', and 'grid search' technique to find the optimal values of the parameters like C, d, ${\sigma}^2$, and ${\varepsilon}$. In the case of ANN, we adopted a standard three-layer backpropagation network, which has a single hidden layer. The learning rate and momentum rate of ANN were set to 10%, and we used sigmoid function as the transfer function of hidden and output nodes. We performed the experiments repeatedly by varying the number of nodes in the hidden layer to n/2, n, 3n/2, and 2n, where n is the number of the input variables. The stopping condition for ANN was set to 50,000 learning events. And, we used MAE (Mean Absolute Error) as the measure for performance comparison. From the experiment, we found that SVR achieved the highest prediction accuracy for the hold-out data set compared to MRA and ANN. Regardless of the target variables (the level of arousal, or the level of positive / negative valence), SVR showed the best performance for the hold-out data set. ANN also outperformed MRA, however, it showed the considerably lower prediction accuracy than SVR for both target variables. The findings of our research are expected to be useful to the researchers or practitioners who are willing to build the models for recognizing human emotions.

• Journal of Global Scholars of Marketing Science
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• v.17 no.2
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• pp.55-73
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• 2007

Festivals are an indispensable feature of cultural tourism(Formica & Uysal, 1998). Cultural tourism festivals are increasingly being used as instruments promoting tourism and boosting the regional economy. So much research related to festivals is undertaken from a variety of perspectives. Plans to revisit a particular festival have been viewed as an important research topic both in academia and the tourism industry. Therefore festivals have frequently been leveled as cultural events. Cultural tourism festivals have become a crucial component in constituting the attractiveness of tourism destinations(Prentice, 2001). As a result, a considerable number of tourist studies have been carried out in diverse cultural tourism festivals(Backman et al., 1995; Crompton & Mckay, 1997; Park, 1998; Clawson & Knetch, 1996). Much of previous literature empirically shows the close linkage between tourist satisfaction and behavioral intention in festivals. The main objective of this study is to investigate the effects of evaluation attributes of cultural tourism festivals on satisfaction and behavioral intention. accomplish the research objective, to find out evaluation items of cultural tourism festivals through the literature study an empirical study. Using a varimax rotation with Kaiser normalization, the research obtained four factors in the 18 evaluation attributes of cultural tourism festivals. Some empirical studies have examined the relationship between behavioral intention and actual behavior. To understand between tourist satisfaction and behavioral intention, this study suggests five hypotheses and hypothesized model. In this study, the analysis is based on primary data collected from visitors who participated in '2006 Gwangju Kimchi Festival'. In total, 700 self-administered questionnaires were distributed and 561 usable questionnaires were obtained. Respondents were presented with the 18 satisfactions item on a scale from 1(strongly disagree) to 7(strongly agree). Dimensionality and stability of the scale were evaluated by a factor analysis with varimax rotation. Four factors emerged with eigenvalues greater than 1, which explained 66.40% of the total variance and Cronbach' alpha raging from 0.876 to 0.774. And four factors named: advertisement and guides, programs, food and souvenirs, and convenient facilities. To test and estimate the hypothesized model, a two-step approach with an initial measurement model and a subsequent structural model for Structural Equation Modeling was used. The AMOS 4.0 analysis package was used to conduct the analysis. In estimating the model, the maximum likelihood procedure was used.In this study Chi-square test is used, which is the most common model goodness-of-fit test. In addition, considering the literature about the Structural Equation Modeling, this study used, besides Chi-square test, more model fit indexes to determine the tangibility of the suggested model: goodness-of-fit index(GFI) and root mean square error of approximation(RMSEA) as absolute fit indexes; normed-fit index(NFI) and non-normed-fit index(NNFI) as incremental fit indexes. The results of T-test and ANOVAs revealed significant differences(0.05 level), therefore H1(Tourist Satisfaction level should be different from Demographic traits) are supported. According to the multiple Regressions analysis and AMOS, H2(Tourist Satisfaction positively influences on revisit intention), H3(Tourist Satisfaction positively influences on word of mouth), H4(Evaluation Attributes of cultural tourism festivals influences on Tourist Satisfaction), and H5(Tourist Satisfaction positively influences on Behavioral Intention) are also supported. As the conclusion of this study are as following: First, there were differences in satisfaction levels in accordance with the demographic information of visitors. Not all visitors had the same degree of satisfaction with their cultural tourism festival experience. Therefore it is necessary to understand the satisfaction of tourists if the experiences that are provided are to meet their expectations. So, in making festival plans, the organizer should consider the demographic variables in explaining and segmenting visitors to cultural tourism festival. Second, satisfaction with attributes of evaluation cultural tourism festivals had a significant direct impact on visitors' intention to revisit such festivals and the word of mouth publicity they shared. The results indicated that visitor satisfaction is a significant antecedent of their intention to revisit such festivals. Festival organizers should strive to forge long-term relationships with the visitors. In addition, it is also necessary to understand how the intention to revisit a festival changes over time and identify the critical satisfaction factors. Third, it is confirmed that behavioral intention was enhanced by satisfaction. The strong link between satisfaction and behavioral intentions of visitors areensured by high quality advertisement and guides, programs, food and souvenirs, and convenient facilities. Thus, examining revisit intention from a time viewpoint may be of a great significance for both practical and theoretical reasons. Additionally, festival organizers should give special attention to visitor satisfaction, as satisfied visitors are more likely to return sooner. The findings of this research have several practical implications for the festivals managers. The promotion of cultural festivals should be based on the understanding of tourist satisfaction for the long- term success of tourism. And this study can help managers carry out this task in a more informed and strategic manner by examining the effects of demographic traits on the level of tourist satisfaction and the behavioral intention. In other words, differentiated marketing strategies should be stressed and executed by relevant parties. The limitations of this study are as follows; the results of this study cannot be generalized to other cultural tourism festivals because we have not explored the many different kinds of festivals. A future study should be a comparative analysis of other festivals of different visitor segments. Also, further efforts should be directed toward developing more comprehensive temporal models that can explain behavioral intentions of tourists.