1. Introduction

With the recent development and diffusion of the communication technology of smartphones, before and after the traditional TV market in 2010, this paradigm has been converted into a smart TV that everyone can enjoy wide ranges of contents and applications. Smart TV, based on the development of broadcasting and communication technology, broadband networks, can not only watch TV for conventionally several contents and applications but also utilize broadcasting services connected to the Internet (Kim, 2012). Smart TVs are commonly used as a terminal for various dramas, movies, and provides video content, animation, and many kinds of services for a variety of applications connected with computer, smart phones via universal Internet.

China utilizes the apps in the Smart TV to an average of 81% annually, and this situation will be more popular in the future (Wang, 2013). In addition, the dramas are constantly increasing to utilize the services with a change in the way of watching such films. Therefore, Smart TV users will foresee the rapid growth of the smart TV market in that they most often use the service apps. When we look at the relevant similar studies, some ongoing studies on the use of smart TV apps related to e-commerce are not enough. Some studies among them have focused on the current state of smart TV apps. Nowadays, there are some leading smart TV in China like "Youku CIBN TV", "AI QI YI", "SO HU TV", "LE TV", "Mango TV", etc., (Fan, 2015). With them. this study focuses on the influence by characteristics of both smart TV and user to highlight how they impact on any of the properties derived perceived ease of use and perceived usefulness, continuous use intention.

2. Theoretical Background

2.1. User Personal Traits

2.1.1. Innovativeness

Goldsmith and Hofacker (1991) showed that innovativeness is how much individuals are interested in adopting innovation in their study, and that how quickly they accepted it than others. Most user-related behaviors are occurred in particular situations, so innovativeness should be measured at special product (Kim, 2010). Lee et al. (2011) has called it an individual innovativeness propensity "enough to accommodate your personal renovation relatively faster than other users in the system."

2.1.2. Self-Efficacy

The self-efficacy is the belief about their own power in that everyone can perform any actions, and that, she is able to organize and act necessary ones to achieve any goals (Bandura, 1986). Compeau (1995) defined it as the assessment about his own ability to use new technologies and new products effectively.

2.2. Characteristics of Smart TV

2.2.1. The User Interface

The user interface, in the study of Ketola and Roykkee (2001), is defined as mutual interactions between users and machines including the display, the input devices, communication method, ergonomic factors (slide, touch, size). Yoon (2010) defined the user interface as the easy degree of learning and memory, and clearness and appropriateness. And it makes a significant impact on perceived usefulness.

2.2.2. Function

Smart TV, just as smartphones, refers to the varieties of functional factors in the form of media convergence like PC, DMB, mobile phone. This can be used for a variety of purposes with wireless internet access, information management, gaming, PC interworking, listening to music, shopping, and such a banking (An, 2013).

2.3. Technology Acceptance Model (TAM)

TAM is consisted of perceived usefulness, perceived ease of use, attitude, intention to use. Davis et. al. (1989) discovered that the role of the attitude was very small impact on other variables. So they decided erasing "attitude", and built the model with the perceived ease of use and the perceived usefulness, see Figure 1. They, the perceived ease of use and the perceived usefulness, usually make direct influences on the use intention

[Figure 1] Information Technology Acceptance Model

Many studies related to information technology acceptance model basically includes perceived usefulness, perceived ease of use like the above model. Intention to use is the concepts of revisit intention for the businessman who he or she has using experiences or the sustainable use intention of some products even though researchers insisted different meanings. Han (2014) defined it as the sustainable use intention to continue using rewards apps.

3. Research Model and Hypothesis

3.1. Research Model and Hypotheses

Research model of this study is depicted in [Figure 2].

[Figure 2] Research Model

Han et al. (2010) proposed self-efficacy, innovativeness, perceived usefulness, and perceived ease of use. Also, they insisted in their study, all variables had significant impacts on each other in the above model. In addition, No (2013) suggested that individual characteristics like innovation orientation, self-efficacy, goal appropriateness affected positive influences on mediators like perceived usefulness, perceived ease of use. Lee (2014) demonstrated that the higher positive impacts on self-efficacy, the greater affirmative ones on perceived usefulness, perceived ease of use.

[H1] user's personal traits based on smart TV will have a positive effect on perceived usefulness.

[H2] user's personal traits based on smart TV will have a positive effect on perceived ease of use.

Lee (2011) demonstrated that the user interface had a significant impact on the efforts expectations. The effort expectations variable is derived from the mixture of the ease of use (Technology Acceptance Model and innovation diffusion theory), complexity (PC models use). Lee and Eune (2013) studied that emotional user interface had a positive effect on the perceived usefulness, while functional user interface had a positive effect on the perceived ease of use. Jeon (2012) demonstrated that function among smart devices characteristics, made a significant effect on the perceived usefulness, perceived ease of use. An (2013) showed function made a positive effect on the perceived usefulness and perceived ease of use.

[H3] Smart TV traits will have a positive effect on the perceived usefulness.

[H4] Smart TV traits will have a positive effect on the perceived ease.

Lee (2012) found that mediators like the perceived ease of use and the perceived usefulness had the positive effect on the intention to use. Park (2013) insisted that the perceived ease of use had a significant effect on the perceived usefulness, and that they, the perceived usefulness and perceived ease of use had positive effects on the intention to use. Kwak (2013) verified that usefulness and ease of use from TAM had significant impacts on continuous use intention. Yu (2013) showed that the perceived usefulness made a positive effect on the continuous use intention. Kim (2014) demonstrated that the perceived usefulness made a significant impact on the sustainable use intention.

[H5] Perceived ease of use will have a positive effect on the perceived usefulness.

[H6] perceived usefulness will have a positive effect on continuous use intention.

[H7] perceived ease of use will have a positive effect on continuous use intention.

3.2. Operational Definition of Variables

In this study, there are some characteristics of the continuous use intention of smart TV (innovativeness, self-efficacy), the properties of the Smart TV (user interface, function) etc. Operational definitions for each variable are shown from [Table 1].

[Table 1] Operation Definitions

4. Empirical Analysis

This study was conducted using questionnaire surveys over 20 days from 20 February 2016 to 10 March 2016 from several areas including Sandong-Seong in China. In this study, empirical analysis was performed with using IBM SPSS Statistics 21.0, and IBM SPSS AMOS 21.0 to verify the hypotheses and research model.

4.1. Demographic characteristics of the study

According to the demographic characteristics of the respondents in this study, first male is 74 respondents (40.7%), female 108 (59.3%), second under 20 age is 8 persons (4.4%), 20~29 is 98 (53.8%), 30~39 is 52 (28.6%), 40~49 is 18 (9.9%), above 50 is 6 (3.3%), third in case of school career, under high school is 13 (7.1%), undergraduate is 32 (17.6%), university graduate is 109 (59.9%), graduate is 28 (15.4%).

[Table 2] Demographic Characteristics

4.2. Reliability Analysis

In this study, the reliability of all the variables is measured in more than 0.7. These are all over the desired level. So the reliability is good for the analysis. The results of reliability analysis are shown in the following [Table 3].

[Table 3] Reliability Analysis

4.3. Exploratory Factor Analysis

All eigen value in the factor analysis is more than 1.0, and loading factor is more than 0.5. So, exploratory factor analysis is fit for empirical analysis. Total cumulative ratio is 6.82%.

4.4. Confirmatory Factor Analysis

Finally, confirmatory factor analysis was performed and removed V8 and V14. The results of confirmatory factor analysis in the overall final variables are =6230.841 (p=0.000, df=359), IFI=0.933, CFI=0.925, RMSEA=0.045.

4.5. Discriment Validity

In this study, after removal of both V8 and V14, the discrement analysis was performed. The results are on [Table 4]. According to it, the biggest correlation coefficient between the latent variables is 0.719. The square of the correlation coefficient, that is the coefficient of determination is 0.52. In this study, all AVE is greater than 0.52. So discriment analysis is significant.

[Table 4] Exploratory Factor Analysis

[Table 5] Confirmatory Factor Analysis

[Table 6] Discriment Validity among Construct​​​​​​​

4.6. Analysis of Structural Model

The results of the fitness of structural model are on the [Table 7]. The indices are as follows: =544.325 (p=0.000, df=323), IFI=0.929, CFI=0.941, RMSEA=0.041. All standardized factor loading value is greater than 0.5, And the SMC value is more than 0.4. Therefore, this model does not have any serious problem to make analysis. The evaluation result of structural model is good as proper model.

[Table 7] Evaluation of Structural Mode

4.8. Discussions of Hypotheses Results

All hypotheses except for the hypothesis [H1-1], [H2-2], [H3-1] were accepted as shown above [Table 8] and [Figure 3]. 

[Figure 3] Measurement of Structural Model

[Table 8] Results of Hypothesis

Innovativeness of user personal characteristics on perceived usefulness is not significant but self-efficacy is. This means that innovativeness does not make any significant influence on perceived usefulness. Instead of that, self-efficacy makes significant influence on perceived usefulness. These results are different from those of Fan (2015). On the contrary, innovativeness on perceived ease of use is positive effect but self-efficacy is not. This means that innovativeness does make any significant influence on perceived ease of use. Instead of that, self-efficacy does not make. User interface of smart TV traits on perceived usefulness is not significant but function is significant. This means that user interface does not make any significant influence on perceived usefulness. Instead of that, function makes significant influence on perceived usefulness. These results are same from those of Fan (Fan, 2015). While user interface on perceived ease of use is affirmative effect also function is same. This means that not only user interface but also function does make any significant influence on perceived ease of use at the same time. Perceived ease of use on both perceived usefulness and continuous use intention is significant. Also perceived usefulness on continuous use intention is meaningful. This means that perceived ease of use makes any significant influences on not only both perceived usefulness but also continuous use intention. Also, perceived usefulness does on continuous use intention.

5. Conclusions

In summary, the results are as follows. First, among user personal traits, innovativeness does not significantly affect perceived usefulness and self-efficacy does not significantly affect perceived ease of use. By interpreting these results, users cannot accept the innovativeness, for example, they cannot understand several kinds of technologies more quickly and easily. This means that the speed of technology development is more faster and faster than users can expect. In other words user cannot understand them fully and cannot utilize them enough. In that point, companies should prepare to get more useful and interesting contents to satisfy users with innovativeness. Second, among user personal traits, innovativeness does affect perceived ease of use significantly but self-efficacy does not significantly affect perceived ease of use. By interpreting these results, users can accept the innovativeness, for example, they can use smart TV effectively and easily as they want. But this situation cannot drive and satisfy their wants. Therefore, they want to have self-efficacies through more diversified technologies for their satisfaction. In that point, companies should further enhance the usability by designing so that users can easily have their self-efficacies when watching smart TV or contents.

Third, among smart TV traits, user interface does not significantly affect perceived usefulness but user interface and function do significantly affect perceived ease of use. By interpreting these results, users cannot accept user interface at present for example, they cannot accept or utilize the level of interface usefully at present. In other words they want to possibly use more convenient and better interface than now. This means that most companies should develop the interface technologies to the customers' satisfied level as soon as possible. For example, companies should focus on the design of the menu, Haya, and functions to simplify the operation to the early users as new services. The technological development will induce industry promotion and it will secure and strengthen company's competitions eventually country's competitiveness.

Fourth, among smart TV traits, function does affect both perceived usefulness and perceived ease of use significantly. This means that users can satisfy function by using it usefully. And that they feel or think perceived ease of use. By interpreting these results, users can use diversified functions when watching smart TV easily and usefully. Fifth, perceived ease of use affects significantly on perceived usefulness. Namely perceived ease of use is very useful to users when using smart TV. This means that they can meet their satisfaction to use them easily and effectively. Most companies should develop rich and significant information contents with easy-to-use. Sixth, not only perceived usefulness but also perceived ease of use do affect continuous use intention significantly. This means that present easiness and usefulness are very helpful for users to use smart TV continuously. Users have intentions to use persistently and sustainably in the future.

These are some strategical implications based on the results of this study from above findings especially for companies. First, companies had better offer a variety of contents, easily use and simple services such as easy viewing methods for users. Second, now China's market can serve many contents freely without strict regulations. So, the competition is very severe. In the new future, strict regulations will be wide spread all over the world. Therefore, companies should develop related technologies through benchmarking to compete with other countries. Third, companies should investigate the essential elements for using smart TV including minute technologies or functions like, for simple examples, smart TV menu screen, easy deployment, installation, etc.

This study has some limitations as follows. First, this study does not consider several variables sufficiently. Following studies should include diversified ones from many factors. Second, because respondents are centered on 20s and 30s, stratified sampling method is useful to collect several samples evenly. Third, results are not generalized because of regional limitations. Next time, regional consideration should be included especially in China.