Heterogeneous Investors and their Changing Demand and Supply Schedules for Individual Common Stocks

Using 550 million limit orders submitted in the Korea Stock Exchange, we estimate demand and supply elasticities of heterogeneous investor types and their changes around the Asian financial crisis. We find that domestic individuals have substantially more inelastic demand and supply curves than domestic institutions and foreign investors. The crisis permanently reduced price elasticities of domestic individuals by 50% but had no effect on those of foreign investors. Institutional changes restricting margin purchases, implemented after the crisis, seem particularly important in explaining the dramatic drop. Information heterogeneity, availability of close substitutes and arbitrage risk also explain time-series variations in elasticities.

Heterogeneous Investors and their Changing Demand and Supply Schedules for Individual Common Stocks

Using 550 million limit orders submitted in the Korea Stock Exchange, we estimate demand and supply elasticities of heterogeneous investor types and their changes around the Asian financial crisis. We find that domestic individuals have substantially more inelastic demand and supply curves than domestic institutions and foreign investors. The crisis permanently reduced price elasticities of domestic individuals by 50% but had no effect on those of foreign investors. Institutional changes restricting margin purchases, implemented after the crisis, seem particularly important in explaining the dramatic drop. Information heterogeneity, availability of close substitutes and arbitrage risk also explain time-series variations in elasticities.

REDESCRIPTION AND PHYLOGENETIC ANALYSIS OF THE MATERIALS ASSIGNED TO THE TAXON CAPTORHINIKOS CHOZAENSIS

“Captorhinikos” chozaensis is a multiple-tooth-rowed captorhinid reptile from the Lower Permian Clear Fork Group, undivided formation. Upon re-examination of the materials associated with the species from both the Chicago Field Museum of Natural History, and the Smithsonian United States National Museum, I reaffirm their affinity and collective identity as a valid taxon. “Captorhinikos” chozaensis does not, however, belong with either of the two members of its genus, C. valensis or “C.” parvus, instead occupying its own branch on the phylogenetic tree of the Captorhinidae. This conclusion is based in strong results from a combined phylogenetic parsimony analysis combined with an analytical apomorphy analysis. I then conclude the current designation “Captorhinikos” chozaensis to be a nomen ambiguum

An Application of Collaborative Web Browsing Based on Ontology Learning from User Activities on the Web

With explosively increasing amount of information on the Web, users have been getting more bored to seek relevant information. Several studies have introduced adaptive approaches to recognizing personal interests. This paper proposes the collaborative Web browsing system that can support users to share knowledge with other users. Especially, we have focused on user interests extracted from their own activities related to bookmarks. A simple URL based bookmark is provided with semantic and structural information by the conceptualization based on ontology. In order to deal with the dynamic usage of bookmarks, ontology learning based on a hierarchical clustering method can be exploited. As a result of our experiments, about 53.1 % of the total time was saved during collaborative browsing for seeking the equivalent set of information, compared with single Web browsing. Finally, we demonstrate implementing an application of collaborative browsing system through sharing bookmark-associated activities

Semantic Co-Browsing System Based on Contextual Synchronization on Peer-to-Peer Environment

In this paper, we focus on a personalized information retrieval system based on multi-agent platform. Especially, they are capable of sharing information between them, for supporting collaborations between people. Personalization module has to be exploited to be aware of the corresponding user's browsing contexts (e.g., purposes, intention, and goals) at the specific moment. We want to recommend as relevant information to the estimated user context as possible, by analyzing the interaction results (e.g., clickstreams or query results). Thereby, we propose a novel approach to self-organizing agent groups based on contextual synchronization. Synchronization is an important requirement for online collaborations among them. This synchronization method exploits contextual information extracted from a set of personal agents in the same group, for real-time information sharing. Through semantically tracking of the users' information searching behaviors, we model the temporal dynamics of personal and group context. More importantly, in a certain moment, the contextual outliers can be detected, so that the groups can be automatically organized again with the same context. The co-browsing system embedding our proposed method was shown 52.7 % and 11.5 % improvements of communication performance, compared to single browsing system and asynchronous collaborative browsing system, respectively

Patterns of Comovement: The Role of Information Technology in the U.S. Economy

Firm-specific variation in stock returns and fundamental performance measures is significantly higher in industries that have a history of more investment in information technology (IT). We hypothesise that IT is associated with creative destruction or product differentiation, either of which can widen the performance difference between winner and loser firms. Thus, economy-level volatility can fall while firm-level volatility rises because firm-specific volatility cancels out in the aggregate. Our results are consistent with rising firm-specific variation in US stocks reflecting a rising pace of creative destruction; and with greater firm-specific variation in richer and faster growing countries reflecting more intensive creative destruction in those economies, though other explanations are probably valid as well.

Introduction to the thematic issue on selected topics from Intelligent Environments 2017

[Excerpt] Introduction: Intelligent Environments (IEs) refer to physical spaces into which IT and other pervasive computing technologies are woven and are used to achieve specific goals for the user, the environment, or both. IEs have the ultimate objective of enriching user experience, better manage and increase user awareness of that environment. The 13th International Conference on Intelligent Environments (IE 17) was held at Seoul, Republic of Korea, and it was a great chance to share the state of the art data analytics methods and technologies. Based on the recommendations from conference committee members, four papers have been invited for this thematic issue. [...