• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.159-177
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• 2015

As smart phones become more common nowadays, mobile instant messengers such as kakao talk and line are used as essential communication tools exchanging information between individuals. Also, the mobile instant messengers extend their use to business area beyond communication between individuals. This study is on how factors of mobile instant messenger such as perceived security, perceived privacy, perceived enjoyment and perceived interactivity affect business continual usage intention through perceived usefulness. The proposed model is based on Expectation-Confirmation Theory of Oliver and Technology Acceptance Mode of Bhattacherjee. For an analysis, 159 survey responses were collected from the office workers in Seoul and nearby cities, having experiences of mobile instant messengers. To validate the proposed research model, PLS analysis is performed with the valid 154 questionnaires. The path analysis results are as follows. First, perceived security has a positive effect on expectation-confirmation. Second, perceived enjoyment has a positive effect on perceived usefulness. Third, perceived interactivity has a positive effect on both perceived usefulness and expectation-confirmation. Fourth, perceived usefulness has a positive usefulness on satisfaction and continual usage intention of mobile instant messenger. Last, expectation-confirmation has a positive effect on perceived usefulness, and satisfaction has a positive effect on continual usage intention of mobile instant messenger. Since the mobile instant messenger may bring a pressure of work and a violation of privacy, it is necessary that the company provide a guideline for use of the mobile instant messenger and establish the in-house mobile instant messenger system.

• The Journal of Information Systems
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• v.25 no.2
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• pp.131-152
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• 2016

Purpose Mobile phones increase the frequency and speed of communication. The most popular mobile application in Korea is KakaoTalk, one of the mobile instant messenger(MIM) services. Although studying mobile services such as SMS, SNS and SNG suggests drawing upon theories in marketing, consumer behavior, psychology to investigate their personal use, research on MIM is scarce. We designed this paper to fill this gap. More specifically, this study is focused on the relationships among consumers psychological variables related to purchase intention to emoticons in context of MIM. Design/methodology/approach Data was obtained from 310 KakaoTalk users in Korea via questionnaire. The data was analyzed by structural equation modeling in order to verify the relationship between variables in the model. Specifically, this study is designed to examine the structural relationships among perceived benefits, perceived risks, trust in messenger service, system quality, trust in platform, and emoticons purchase intention. Findings The findings of this study are as follow. First, perceived benefits and perceived risks had a significant impact on trust in MIM service(e.g. KakaoTalk). Specifically, while perceived benefits had a positive effect on trust in MIM service, perceived risks had a negative effect on trust in MIM service. Second, trust in messenger service also had a positive impact on system quality. Third, trust in messenger service and system quality had a positive effect on trust in platform(e.g. Kakao platform) directly. Lastly, trust in platform had a positive influence on emoticons purchase intention in KakaoTalk messenger.

• Convergence Security Journal
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• v.14 no.6_2
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• pp.53-62
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• 2014

This study is aimed what improvement for an illegality detective aagency and messenger office. First, administrators or managers who are involved with personal information protection should make a full-fledged effort to gather information. Second, counseling or related programs should be provided for small and mid-sized security firms to guarantee thorough personal information protection. Third, Korea Security Association should improve the educational system related to personal information protection to resolve problems with this education currently provided for managers and employees of these companies.

• Korean Journal of Poultry Science
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• v.23 no.3
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• pp.113-119
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• 1996

A series of experiments were conducted to investigate the role of protein kinase C (PKC) as a second messenger in vasoactive intestinal peptide (VIP) mediated prolactin secretion. Primary pituitary cells (106 cells/treatment) were separated from laying hens and incubated in M-199 with 5% chicken serum and 5% fetal calf serum. The VIP(0.1 $\pi$M) treatment enhanced prolactin Secretion into media upto 9-fold during 48-h incubation. The phorbol 12-myristate 13-acetate (PMA), a PKG agonist, increased prolactin secretion upto 2-fold at 0.1 nM PMA (P<0.01), and the prolactin secretion was not significantly higher than this concentration. Staurosporine (ST; 1.0$\pi$M) a PKC antagonist, decreased by 70% of 0.1 $\pi$M VIP-stimulated prolactin secretion and by 48% of 10 ${\mu}$M PMA-stimulated prolactin secretion (P<0.01). However, pituitary cell prolactin content did not differ in any treatment (P>0.05). In conclusion, these results indicate that the PKC second messenger system is involved in VIP-stimulated prolactin release in chicken primary pituitary cell culture.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.25-29
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• 1997

To study the mechanism of lipocortin-1, the 37 kDa protein, one of the annxin superfamily thought to be a second messenger during the Glucocorticoid dependent anti-inflammatory action, the gene for lipocortin-1 binding protein was isolated using the yeast two hybrid assay, the yeast based genetic assay recognizing the protein-protein interaction. The results showed that this gene has a weak homology to the for the human serine proteinase.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.520-528
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• 1996

The involvement of the cyclic AMP (cAMP) effector system in the release of endogenous dopamine and acetylcholine from the rat neostriatum was assessed. Forskolin, an activator of adenylate cyclase, was used to enhance cAMP production, and the consequence of this enhancement on the spontaneous and potassium stimulated release of dopamine and acetylcholine was evaluated. Neostriatal slices were prepared from Fischer 344 rats and after a preincubation period the release of each endogenous neurotransmitter was measured from the same slice preparation. To measure acetylcholine release the slice acetylcholinesterase (AChE) activity was inhibited with physostigmine, but the release from slices with intact AChE activity was also determined (choline, instead of acetylcholine was detected in the medium). Under both conditions forskolin induced a significant dose-dependent increase in the potassium-evoked release of dopamine. In the same tissue preparations the release of neither acetylcholine (AChE inhibited) nor choline (AChE intact) was affected by forskolin. The results indicate that the CAMP second messenger system might be involved in neuronal mechanisms that enhance neostriatal dopamine release, but stimulation of this second messenger by forskolin does not further enhance neostriatal acetylcholine release.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.102.2-103
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• 2001

• Journal of the Korea Convergence Society
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• v.10 no.5
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• pp.189-201
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• 2019

The aim of this study is to investigate the relationship between communication motive, fatigue and loneliness in mobile environment. According to previous research, the most important communication motive in mobile environment is pleasure. Therefore, pleasure was selected as a representative communication motive. To do this, we collected data for empirical analysis from mobile messenger users using questionnaire. We found that pleasure has a negative effect on loneliness. Second, pleasure has a negative effect on connection, function, and focus. On the other hand, pleasure has no effect on delivery and relationship fatigue. Finally, function and focus have a positive effect on loneliness. On the other hand, connection, delivery, and relationship fatigue have no effect on loneliness. As a result of the research, it is possible to reduce the function and focus fatigue due to the use of the mobile messenger by adding the functions that cause the enjoyment of using the messenger. In addition, the addition of fun-inducing features can also reduce loneliness caused by the use of mobile messenger. Future research will also need to identify factors that may reduce connection and relationship fatigue.

• Management & Information Systems Review
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• v.35 no.1
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• pp.207-233
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• 2016

Currently mobile messenger industry, based on mobile application, is growing. And it has aroused innovative change, offering services in various forms beyond the form simply sharing messengers. Also because messenger securities are becoming personalized and intelligent, the importance of more diverse mobile applications' securities is increasing. This study carries out the empirical study of the causal relationship that the factors of using application services influence on security recognition and security Intention of mobile securities, and consequentially impact upon protection of personal information of users. In order that, we present the research model which prime variables of SDT, which emphasized on natural immanent motivation of human, applied to. To verify the research model of this study empirically, we conducted a survey targeting the public and university students which have ever used mobile messenger applications. With this, we desire to contribute to emphasizing the significance of individual messenger security and playing a positive role to develop security guide for consumers. The path analysis results are as follows. First, perceived autonomy has a positive effect on both security awareness and security intention. Second, perceived competence has a positive effect on security intention. Third, perceived relatedness has a positive effect on both security awareness and security intention. Last, security awareness and security intention. have a positive effect on privacy protection behavior. Through emphasizing the importance of the security of the messenger of individuals and contribute to a positive role for development of the necessary security guidelines to consumers.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.149-158
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• 2010

A messenger program in this paper was designed and implemented using Use Case Diagram, Class Diagram, Activity Diagram, and Sequence Diagram. We selected total 7 major functionalities such as PC server, login, friends management, chatting, file transfer, account management, etc. The followings are various implementation results from this paper. First, developers could easily understand the desired product and programming flow from using UML Diagrams. Second, PDA users could communicate with developers for a long time without time constraints. Third, there was high usability of UML Diagram in the phase of objected-oriented analysis. Forth, it was easy to update and maintain a program.