• Title/Summary/Keyword: Test of hypothesis

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Discussion of Preliminary Design Review for MIRIS, the Main Payload of STSAT-3

  • Han, Won-Yong;Jin, Ho;Park, Jang-Hyun;Nam, Uk-Won;Yuk, In-Soo;Lee, Sung-Ho;Park, Young-Sik;Park, Sung-Jun;Lee, Dae-Hee;Ree, Chang-H.;Jeong, Woong-Seob;Moon, Bong-Kon;Cha, Sang-Mok;Cho, Seoung-Hyun;Rhee, Seung-Woo;Park, Jong-Oh;Lee, Seung-Heon;Lee, Hyung-Mok;Matsumoto, Toshio
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.27.1-27.1
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    • 2008
  • KASI (Korea Astronomy and Space Science Institute) is developing a compact wide-field survey space telescope system, MIRIS (The Multi-purpose IR Imaging System) to be launched in 2010 as the main payload of the Korea Science and Technology Satellite 3. Through recent System Design Review (SDR) and Preliminary Design Review (PDR), most of the system design concept was reviewed and confirmed. The near IR imaging system adopted short F/2 optics for wide field low resolution observation at wavelength band 0.9~2.0 um minimizing the effect of attitude control system. The mechanical system is composed of a cover, baffle, optics, and detector system using a $256\times256$ Teledyne PICNIC FPA providing a $3.67\times3.67$ degree field of view with a pixel scale of 51.6 arcsec. We designed a support system to minimize heat transfer with Muti-Layer Insulation. The electronics of the MIRIS system is composed of 7 boards including DSP, control, SCIF. Particular attention is being paid to develop mission operation scenario for space observation to minimize IR background radiation from the Earth and Sun. The scientific purpose of MIRIS is to survey the Galactic plane in the emission line of Pa$\alpha$ ($1.88{\mu}m$) and to detect the cosmic infrared background (CIB) radiation. The CIB is being suspected to be originated from the first generation stars of the Universe and we will test this hypothesis by comparing the fluctuations in I (0.9~1.2 um) and H (1.2~2.0 um) bands to search the red shifted Lyman cutoff signature.

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The Effects of Consumption Value of Smartphone Users on Relational Factors and Repurchase Intention (스마트폰 이용고객의 소비가치가 관계적 요인과 재구매 의도에 미치는 영향)

  • Kim, Hyun-Kyung;Cho, Hyun-Jin
    • Journal of Distribution Science
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    • v.11 no.4
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    • pp.73-80
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    • 2013
  • Purpose - As the smart-phone market adds new technologies and introduces new marketing trends, competition among companies is getting fierce. Now, smart-phone companies need to pay attention not only to attaining new customers but also to retaining customers, which means managing relationships to prevent customer defection. Therefore, how to satisfy customer needs and maintain long-term relations are both important to make consistent progress in the rapidly changing smart-phone market. To illustrate this point, the study focuses on analyzing the effects of consumption value on relational factors and buying intentions among smart-phone users. First, consumption value was divided into functional, economic, and emotional values. After that, the effects of these values on satisfaction and brand trust were confirmed. Additionally, effects of satisfaction and brand trust on repurchase intention were analyzed. Research design, data, and methodology - The data was collected in a self-administered survey among 270 undergraduate students, using smart-phones between June 4th-12th, 2012. A total of 257 questionnaires were collected and used for the data analysis. A path analysis based on Lisrel 8.54 was used for the hypothesis test. Consumption value was divided into functional, economic, and emotional values. Subsequently, the effects of these values on satisfaction and trust in the brand were confirmed. Additionally, the effects of satisfaction and trust in the brand on repurchase intention were analyzed. Results - First, functional value, economic value, and emotional value - especially emotional value - were revealed to have positive effects on satisfaction. Second, emotional value was shown to have positive effects on brand trust, while functional and economic values did not. Third, satisfaction had positive effects on brand trust. In considering the relative influence on brand trust, satisfaction was the most crucial factor. It is clear that in the evaluation of the direct experience, using the product or the service plays an important role in building brand trust. Fourth, satisfaction and brand trust positively influenced repurchase intention. This indicates that both factors must be achieved to induce the repurchase Intention among customers. Conclusions - One can see that the enjoyable emotions consumers feel while using smart-phones is the most important factor in increasing levels of satisfaction. Moreover, this indicates that consumers pursue economic desires along with convenient functions in order to reduce opportunity costs. Additionally, consumers are affected by psychological and emotional messages in building trust, rather than practical and rational ones. Thus, in order to appeal to young clients as an attractive brand in the smart-phone market, approaching customers with an emotional value is recommended. In addition, in order for the brand to gain trust, the overall experience the consumer feels while using smart phones should be maximized. After all, one must fulfill the consumers' desire for a new experience and show a willingness to faithfully accomplish the responsibility of the brand to strengthen relationships with customers in the smart-phone market.

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The Behavioral Analysis of the Trading Volumes of Gwangyang Port: Comparison with Incheon and Pyeongtaek-Dangjin Port (광양항의 물동량 행태분석: 인천항, 평택.당진항과 비교)

  • Mo, Soowon
    • Journal of Korea Port Economic Association
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    • v.28 no.3
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    • pp.111-125
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    • 2012
  • This study investigates the behavioral characteristic difference of the container volumes of three ports-Gwangyang, Incheon, and Pyeongtaek-Dangjin. All series span the period January 2003 to December 2011. I first test whether the series are stationary or not. I can reject the null hypothesis of a unit root in each of the level variables and of a unit root for the residuals from the cointegration at the 5 percent significance level. I hitherto make use of error-correction model and find that Gwangyang port is the slowest in adjusting the short-run disequilibrium, whereas the adjustment speed of Incheon is much faster than that of Gwangyang. The impulse response functions indicate that container volumes increase only a little to the negative shocks in exchange rate, while they respond positively to the shocks in the business activity in a great magnitude and decay very slowly to its pre-shock level. meaning that the shocks last very long. The accumulative response to the exchange rate increase of 20 won per dollar and the 5 point industrial production increase is the smallest in Gwangyang, no more than a half of that of two ports. The intervention-ARIMA models also forecast that Gwangyang port will have much lower growth rate than Incheon and Pyeongtaek-Dangjin port in trading volumes.

Prediction of the direction of stock prices by machine learning techniques (기계학습을 활용한 주식 가격의 이동 방향 예측)

  • Kim, Yonghwan;Song, Seongjoo
    • The Korean Journal of Applied Statistics
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    • v.34 no.5
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    • pp.745-760
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    • 2021
  • Prediction of a stock price has been a subject of interest for a long time in financial markets, and thus, many studies have been conducted in various directions. As the efficient market hypothesis introduced in the 1970s acquired supports, it came to be the majority opinion that it was impossible to predict stock prices. However, recent advances in predictive models have led to new attempts to predict the future prices. Here, we summarize past studies on the price prediction by evaluation measures, and predict the direction of stock prices of Samsung Electronics, LG Chem, and NAVER by applying various machine learning models. In addition to widely used technical indicator variables, accounting indicators such as Price Earning Ratio and Price Book-value Ratio and outputs of the hidden Markov Model are used as predictors. From the results of our analysis, we conclude that no models show significantly better accuracy and it is not possible to predict the direction of stock prices with models used. Considering that the models with extra predictors show relatively high test accuracy, we may expect the possibility of a meaningful improvement in prediction accuracy if proper variables that reflect the opinions and sentiments of investors would be utilized.

Effects of Entrepreneurship, Social Support and Entrepreneurial Mentoring on Entrepreneurial Intention (기업가정신, 사회적 지지 및 창업 멘토링이 창업의도에 미치는 영향)

  • Hahn, Mie Kyoung;Ha, Kyu Soo
    • The Journal of the Korea Contents Association
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    • v.21 no.10
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    • pp.444-456
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    • 2021
  • Economic abundance and the development of medical technology led to an aging society with an average life expectancy of 100 years, but retiring from the labor market at the age of 65 has become more difficult. This study aims to identify the influence of entrepreneurship, social support, and entrepreneurship mentoring as an effective support method to increase the entrepreneurial intention in order to enhance the entrepreneurial intention as an adult's second career development. In this study, data were collected using questionnaires from 340 adults, but only 319 were selected because 21 were judged to be inappropriate. For statistical analysis, SPSS 18.0 was used, and reliability test, factor analysis, and multiple regression analysis were used for hypothesis testing. The research results are as follows. First, as a result of examining the effects of adult entrepreneurship factors on entrepreneurship, it was found that among entrepreneurship, innovation and initiative had a significant positive (+) effect on entrepreneurship. Second, as a result of examining the effect of social support on entrepreneurial intention, it was found that family support had a significant negative (-) effect on entrepreneurial intention. Third, as a result of examining the effect of entrepreneurship mentoring on entrepreneurial intentions, it was found that role models and mentors had a positive (+) effect on entrepreneurial intentions. Fourth, as for the mediating effect of entrepreneurial efficacy, there were significant mediating effects of innovativeness → entrepreneurial efficacy → entrepreneurial intention, role model → entrepreneurial efficacy → entrepreneurial intention, mentor → entrepreneurial efficacy → entrepreneurial intention.

The Role of Gender difference and Interpersonal Problems in the relationship between Internal Narcissism and on Middle School Students' SNS Addiction Tendency (내현적 자기애와 SNS 중독경향성의 관계에서 성 차이와 대인관계문제의 조절된 매개효과)

  • Lim, Su Jin;Kim, Yu Yeon
    • Korean Journal of School Psychology
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    • v.17 no.1
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    • pp.109-123
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    • 2020
  • The purpose of this study was to understand path of internal narcissism toward SNS addiction tendency of middle school students. The study intended to test the hypothesis that internal narcissism personality would lead to the SNS addiction tendency through interpersonal problems and that the internal narcissism effect on the interpersonal problems can depend on Gender difference The subjects of the study were 240 middle school students (95 male and 145 female students) in Gwangju area. The descriptive statistics, correlation analysis, and SPSS Macro PROCESS Model were used. The results of the study are as follows. First, there was a significant positive interpersonal problems mediation efffect between inner narcissism and SNS addiction tendency of middle school students. Second, as a result of examining Gender difference moderatiing effect between internal narcissism, and interpersonal problems relationship. according to gender difference statistically significant. Third, Moderated mediation effect of gender difference and interpersonal problems between internal narcissism personality and SNS addiction tendency relationship is statistically significant. Recently, social networking has become a serious problem in our society and it shows the highest rate of addiction in early middle school students. The purpose of this study was to investigate the effects of psychological factors of inner narcissism and interpersonal problems on the SNS addiction tendency, focusing on the gender differences in middle school students, and to provide basic data to prevent adolescent SNS addiction problems have.

A Study on The Effect of Organizational Culture on Job Satisfaction and Organizational Commitment In ICT Enterprises (ICT 기업의 조직문화가 조직구성원 직무만족과 조직몰입에 미치는 영향에 관한 연구)

  • Lee, Yoeng-Taak
    • Management & Information Systems Review
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    • v.36 no.4
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    • pp.149-166
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    • 2017
  • The purpose of this study puts stress on effects of job satisfaction and organizational commitment depending on the type of organizational culture of ICT enterprises. This study utilized the 6th Human Capital Corporate Panel(HCCP) data from Korea Research Institute for Vocational Education & Training to analyze the effects of organizational culture in ICT enterprises on the job satisfaction and organizational commitment. The Samples are managers, supervisor, and employees in ICT industries who replied thorough the 6th HCCP. Answers from 875 people, except inappropriate answers, were used to test a hypothesis. In order to do that, reliability analysis and correlation analysis and regression analysis, utilizing the SPSS 24.0 & Amos 18.0, were used to analyze the effects of organizational culture on the job satisfaction and organizational commitment in ICT enterprises. With the purpose of this study, organizational cultures in ICT enterprises have different effects on job satisfaction and organizational commitment. The group culture, development culture, rational culture and hierarchy culture have a positive effects on job satisfaction. And the group culture, development culture and rational culture have a positive effects on organizational commitment. Whereas, hierarchy culture have no effects on organizational commitment. Also, job satisfaction have a positive effects on organizational commitment. Among four cultures of ICT enterprises, the importance of group culture should be stressed. According to the result of empirical analysis, group culture has the most positive impact on job satisfaction, contrary to the expectation that development culture might be the one. So far, the group culture, which emphasizes organizational flexibility, integration, trust, teamwork, high participation, royalty and morale, have positive impact on the organizational employees the most.

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The Effect of Corporate Social Responsibility on Corporate Image and Corporate Performance (기업의 사회적 책임활동이 기업 이미지 형성과 기업 성과에 미치는 영향에 관한 연구: 공유가치창출 인지정도에 따른 차이비교)

  • Lee, Don-Gon;Lee, Myung-Jin
    • Journal of Distribution Science
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    • v.12 no.9
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    • pp.101-112
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    • 2014
  • Purpose - Recently, although corporate social responsibility activities have been increasing in size, they do not have to achieve qualitative improvements and can be passive and cost consuming. Therefore, companies should make quantitative as well as qualitative improvements in their efforts in corporate social responsibility activities. In this study, the classification of social responsibility activities in a variety of studies was analyzed through a more specific path than in previous studies. Corporate behavior image, social behavior image, and corporate contributions image were analyzed through a more detailed analysis of performance. This study suggests that more detailed and concentrated social responsibility activities be pursued by forming companies. Research design, data, and methodology - The purpose of study is to gauge the corporate need for a more intensive, specific area of CSR activities. For this purpose, the sample of consumers that were targeted for CSR activities, recognized as 261 persons, have been investigated. Through a theoretical discussion on previous research, nine hypotheses were established on corporate image, the influence of corporate performance on CSR, and the CSV regulation effect. In order to test the hypothesis, a survey was conducted on 261 male and female consumers who were targeted for CSR, being persons in their 20s to 40s. PASW Statistics 18.0 and AMOS 18.0 were used for statistical analysis. Results - Corporate behavior image was formed through legal responsibility activities and economic responsibility activities. In addition to economic responsibilities, ethical responsibilities and environmental responsibilities were confirmed to have influence on social behavior image. Corporate social responsibility and philanthropic responsibility were confirmed to have influence on economic contribution image. Corporate image has positive effects on brand attitude, corporate reputation, and corporate competition. In addition, when CSV awareness is high, consumers perceive corporate image only through economic responsibility. However, when CSV awareness is low, economic responsibility as well as legal responsibility through charitable activities form the corporate image that influences the brand attitude and corporate reputation, as well as corporate competitiveness. It would appear that the area of corporate social responsibility needs more intensive management for corporate image and corporate competitive advantage. Conclusion - First, the findings of this study show that each CSR activity has a different effect on corporate image and thus, the corporate image influences corporate performance in distinct ways, depending on the CSR activity. This implies that reactive strategies should be tailored to the required image. Second, there is a difference in CSV awareness between groups. When the CSV awareness is low, we can confirm that legal responsibility activities have an especially significant effect on corporate image, implying that corporations should pursue their economic objectives within legal regulations and need to invest significant time and effort for this. This study has limited generalization potential because the result of the model fit has insufficient reference value. In future research, we need to approach various dimensions of corporate performance.

Tourism Resource Development for the Activation of Regional Economic and the Roll of Tourism Policy (지역경제 활성화를 위한 관광자원개발과 관광정책의 역할)

  • Kim, Tae-Heon;Park, Suk-Jin
    • The Journal of the Korea Contents Association
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    • v.11 no.5
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    • pp.403-412
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    • 2011
  • This study aims at proposing clear direction of tourism policy through analyzing the correlation between tourism resource, tourism system and activation of regional economic. A total of 283 samples were ultimately collected in survey of 300 researchers from the national and public institutes in provinces Chungchong-do and Kyungsang-do in July 2010 alone. SPSS 15.0 and AMOS 6.0 were used to test the model. Analysis showed that the more regional tourism resources have more significant effect on tourism system and tourist-attracting strategy, and that tourism system exerts influence on tourist-attracting strategy. So it was proved that the tourism policy effects meaningfully on vitalization of regional economic, and it was confirmed that the tourism system is more effective on the energization of regional economic than the tourist-attracting strategy. But the hypothesis has been rejected unexpectedly that tourist attractions have consequences for the activation of regional economic. It establishes the fact that it is useless for regional economy regardless of abundant regional tourism resources, if the tourism policy is not concretely in force. Therefore, Korean government must intercept overissue and overlapping investments on tourism development by the local government and induce qualitative growth of tourism sector through upgrading of development guidelines and the criteria for selecting tourism special zone, regional festival and cultural assets, and its continuous assessment and management. And it is desirable to enforce the connected cooperation projects between local governments and the 5+2 great-sphere economic blocs on government-level.

A Study on the Effects of Solely Operated Beauty Salon's Relational Benefits on Recommendation and Defection Intentions: Mediating Effects of Customer Satisfaction (1인 미용실의 관계혜택이 추천의도와 이탈의도에 미치는 영향에 관한 연구 : 고객만족의 매개효과)

  • Jeon, Seon-Bok
    • Journal of Digital Convergence
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    • v.14 no.1
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    • pp.413-425
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    • 2016
  • This study investigated what effects the relational benefits perceived by the customers of solely operated beauty salons have on customer satisfaction, recommendation intention, and defection intention through the convergence of cosmetology and business management. For this, a total of 322 customers of solely operated beauty salons were chosen as final valid samples. For data analysis, frequency analysis, reliability analysis, confirmatory factor analysis, and correlation analysis were performed using SPSS 15.0 and AMOS 18. For a hypothesis test, lastly, path analysis was conducted using structural equation modeling. The study results found the following: First, among the relational benefits perceived by the customers of solely operated beauty salons, confidence benefits and social benefits had a positive effect on customer satisfaction. Second, the relational benefits perceived by the customers of solely operated beauty salons had a positive effect on recommendation intention. Third, confidence benefits and social benefits had a negative effect on defection intention. Fourth, customer satisfaction had a positive effect on recommendation intention. Fifth, customer satisfaction had a negative effect on defection intention. Sixth, in relationship between the relational benefits perceived by the customers of solely operated beauty salons and recommendation/defection intention, customer satisfaction revealed partial mediating effects.