993 research outputs found

    Social security trust fund (SSTF), the government fiscal use of the SSTF, and intergenerational equity

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    In this dissertation we pay particular attention to changing share of unfunded and fully funded SS systems and to the alternative government fiscal policies regarding the use of the social security trust fund (SSTF) in order to investigate the resulting economic and intergenerational equity consequences. To carry out this investigation, we develop a computational two periods lived overlapping generations model with production in which a wide range of possible SS arrangements and possible government fiscal uses of the SSTF are incorporated in parameterized form. The parameterization of the SS system permits the comparative dynamic study of a family of SS systems;Several important results are discovered during the course of our simulations. First, the particular type of SS arrangement and the government use of the SSTF may not be particularly important when some conditions are satisfied. The chief reasoning for this is that agents do not distinguish between types of SS arrangement and the government fiscal polices as long as their lifetime utilities remain unchanged;Second, SS actuarial status is not an ineffective measure of intergenerational equity although it is one standard measure used in the analysis of SS systems. The reason for this is that, although SS actuarial status may affect lifetime utility, it is not the sole factor that does so;Third, contrary to the general belief that one of the major underlying motivations behind the transformation of SS system is a wide range of demographic changes, having a particular population structure does not necessarily make one type of SS system preferable to other types of SS system. For instance, more funding for a SS system is justified given either a decreased labor share or an increased consumption time preference but not necessarily given a decreased population growth rate

    A User-Oriented Contents Recommendation System in Peer-to-Peer Architecture

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    Recommender system is a popular technique for reducing information overload and finding digital contents that is most valuable to users. However, most recommender systems are based on a centralized client-server architecture in which servers and clients represents contents providers and users respectively. The existing recommender systems depend on contents providers and give a number of disadvantages to users. Therefore, we propose a recommender system based on a distributed P2P architecture that has originated with user-oriented principle rather than business itself. The proposed system consists of fully functioning personal recommender agents that automatically select neighbors and recommend contents. The agents learn user preference from users’ content usage without requiring users’ explicit ratings. We believe that the suggested P2P based recommender system should provide the users with more qualified recommendations, while it reduces the effort and time of users

    MOBICORS-Movie: A MOBIle COntents Recommender System for Movie

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    In spite of the rapid growth of mobile multimedia contents market, most of the customers experience inconvenience, lengthy search processes and frustration in searching for the specific multimedia contents they want. These difficulties are attributable to the current mobile Internet service method based on inefficient sequential search. To overcome these difficulties, this paper proposes a MOBIle COntents Recommender System for Movie (MOBICORS-Movie), which is designed to reduce customers’ search efforts in finding desired movies on the mobile Internet. MOBICORS-Movie consists of three agents: CF (Collaborative Filtering), CBIR (Content-Based Information Retrieval) and RF (Relevance Feedback). These agents collaborate each other to support a customer in finding a desired movie by generating personalized recommendations of movies. To verify the performance of MOBICORS-Movie, the simulation-based experiments were conducted. The experiment results show that MOBICORS-Movie significantly reduces the customer’s search effort and can be a realistic solution for movie recommendation in the mobile Internet environment

    A Comparative Analysis of International and Chinese Electronic Commerce Research

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    Due to the growth of the Internet and e-commerce, both practitioners and researchers are in the midst of a social, business and culture revolution. Internet and e-commerce related research has been developed and grown up by United States, but China has become one of the most exciting research areas. This literature review consists of 1044 journal articles published between 1993 and 2003 in fourteen International and Chinese journals. The articles are classified by a scheme that consists of four main categories: application areas, technological issues, support and implementation and others. Based on the classification and analysis of e-commerce related researches, we present the current state of International and Chinese research and discuss the differences between them

    The Impact Of Booth Recommendation System On Exhibition Attendees\u27 Unplanned Visit Behavior: An Extrinsic-Intrinsic Dichotomy Perspective

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    Our study on unplanned behaviour theory have examined the effect of booth recommendation system (BRS) on exhibition arise from either an extrinsic or intrinsic motivation. Previous studies, however, ignored the importance of the unplanned behavioural effectiveness through BRS that bonds extrinsic and intrinsic motivation together to deliver unexpected outcomes in exhibition. In this paper, we propose a model of the impact of BRS where perception of usefulness and threat to freedom of choice mediates the effect of both extrinsic and intrinsic motivation on unplanned booth visit behavior. We collected data from 101 visitors of exhibition and analyzed it using the Partial Lease Square (PLS) method. Our findings, interestingly, show that only intrinsic motivations (escape, attraction) significantly influence both perceived usefulness of BRS and threat to freedom of choice, however extrinsic motivation (information) does not significantly influences. Perceived usefulness of BRS mediates directly the effect of escape and attraction on unplanned booth visit behavior. The results and implications are further discussed

    Improvement in carrier mobility of metal oxide thin-film transistor by a microstructure modification

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    Metal oxide thin-film transistors (TFTs) have been rapidly penetrating as an emerging backplane technology for the next generation high pixel density, large-size liquid crystal displays and organic light-emitting diodes panels because of their intriguing properties such as their high field-effect mobility, low subthreshold gate swing, good uniformity, low temperature processing capability, and transparency to visible light.[1-3] However, the typical field-effect mobility of IGZO TFTs in the practical production line is ~10 cm2/Vs, which is still not enough to drive the high-end flat panel displays with the ultra-high-definition, large size ( 60 inch) and high frame rate ( 240 Hz). One of ways to improve the mobility of electron carriers in metal oxide semiconductor would involve the lattice ordering, which leads to the substantial reduction in the carrier scattering with the semiconductor. Approach that seeks to utilize the crystallization of metal oxide semiconductor has yet to be attempted despite the potential scientific and engineering implication. In this presentation, we explored the metal-induced crystallization of amorphous zinc thin oxide (a-ZTO) and indium gallium zinc oxide (a-IGZO) semiconductor at a low temperature. The fabricated crystalline ZTO TFTs exhibited a high field-effect mobility of 33.5 cm2/Vs, subthreshold gate swing of 0.40 V/decade, and ION/OFF ratio of \u3e 5 107. The method in this study is expected to be applied to any type of metal oxide semiconductor. Acknowledgment This study was supported by the National Research Foundation of Korea (NRF) grant funded the Korean government (NRF-2015R1A2A2A01003848) and the industrial strategic technology development program funded by MKE/KEIT (10051403). References 1. K. Nomura et al., Nature 432, 488 (2004). 2. T. Kamyia et al., Sci. Technol. Adv. Mater. 11, 044305 (2010). 3. J. Y. Kwon and J. K. Jeong, Semicond. Sci. Technol. 30, 024002 (2015

    Improvement of the Usability of Online Mentoring Website

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    The purpose of this study is to improve the usability of the current online mentoring website by deriving what should be improved through assessment and reflecting it to system improvement. The related data such as search log and Think Aloud were collected from user groups (9 users in total), and usability was tested according to the predefined test procedures. The collected data were analyzed, using quantitative methods. In terms of search log, the related items including effectiveness, efficiency, satisfaction and error were quantified according to usability testing standards. Then, descriptive statistics was performed. According to usability comparison before and after system improvement, it has mostly improved such as improved effectiveness (increase by 15 points), better efficiency (reduction by 41 seconds), increase in satisfaction (by 8 points) and decrease in error frequency (decrease by 1.2 times). Usability testing should be viewed as a process, not outcome itself. Therefore, it could be used during system prototype in addition to the current system and useful in system improvement

    Elevation of serum lactate dehydrogenase in patients with pectus excavatum

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    INTRODUCTION: Pectus excavatum is the most common congenital chest wall deformity and the depression of the anterior chest wall, which compresses the internal organs. The aim of the present study is to investigate the effects of pectus excavatum on blood laboratory findings. MATERIAL AND METHODS: From March 2011 to December 2011, 71 patients with pectus excavatum who visited Seoul Saint Mary Hospital for Nuss procedure were reviewed and analyzed. The blood samples were routinely taken at the day before surgery and pectus bar removal was usually performed in 2 to 3 years after Nuss procedure. To investigate the effects on blood laboratory findings, preoperative routine blood laboratory data and postoperative changes of abnormal laboratory data were analyzed. RESULTS: Only lactate dehydrogenase (LDH), one of 26 separate routine laboratory tests, was abnormal and significantly elevated than normal value (age <10, p = 0.008; age ≥10, p < 0.001). However, there was no significant correlation between LDH levels and severities of pectus excavatum. The symmetric subgroup had significantly higher LDH level than the asymmetric subgroup (p <0.001) and there was a significant decrease of LDH level after correction of deformity (p = 0.017). CONCLUSION: In conclusion, only LDH, one of the routine laboratory tests, was significantly elevated than normal value, which was thought to be caused by etiologies of pectus excavatum and the compression of the internal organs. Further studies on LDH including isoenzyme studies in patients with pectus excavatum will be needed, and these studies will provide a deeper and wider comprehension of pectus excavatum
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