• Journal of KIISE:Computing Practices and Letters
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• v.14 no.6
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• pp.567-581
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• 2008

As the size of the web is growing explosively, search engines are becoming increasingly important as the primary means to retrieve information from the Internet. A search engine periodically downloads web pages and stores them in the database to provide readers with up-to-date search results. The web crawler is a program that downloads and stores web pages for this purpose. A large-scale search engines uses a parallel web crawler to retrieve the collection of web pages maximizing the download rate. However, the service architecture or experimental analysis of parallel web crawlers has not been fully discussed in the literature. In this paper, we propose an architecture of the parallel web crawler and discuss implementation issues in detail. The proposed parallel web crawler is based on the coordinator/agent model using multiple machines to download web pages in parallel. The coordinator/agent model consists of multiple agent machines to collect web pages and a single coordinator machine to manage them. The parallel web crawler consists of three components: a crawling module for collecting web pages, a converting module for transforming the web pages into a database-friendly format, a ranking module for rating web pages based on their relative importance. We explain each component of the parallel web crawler and implementation methods in detail. Finally, we conduct extensive experiments to analyze the effectiveness of the parallel web crawler. The experimental results clarify the merit of our architecture in that the proposed parallel web crawler is scalable to the number of web pages to crawl and the number of machines used.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.265-272
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• 2011

Even though concrete is the most important material for building structures, its intrinsic gray color degrades urban esthetics. In order to improve this problem, coloring methods of mixing pigment in concrete batch and painting the surface of concrete surface have been tried. However, applications of the coloring methods in construction field are difficult due to high cost and low durability. Recently, acid stain agent is emerging as a new coloring method for concrete. It is able to apply a remarkably thin colored layer on a concrete surface from chemical reaction between acid and alkaline solutions. This study has examined the changes and variations of the surface layer of mortar specimen from chemical reaction of acid stained agents. The colors were changed into natural irregular stains according to aging. After the staining, no shape change was found from visible inspections. Microstructure of the colored surface applied with acid stained agent was much rougher than that of original mortar. When the colored layer was compared to original surface, crystals of hydrate such as $Ca(OH)_2$ and C-S-H gel were observed. Surface hardness was same or slightly higher in the colored layer. The value of pH was reduced by approximately 10%, weight contents of elements such as Ca, Si, and Al were low. In the chemical composition of the colored layer, the non-cement based elements of Mn, Cr, and Cu increased. Also, Fe and alkali elements of K and Na increased.

• Journal of The Korean Digital Architecture Interior Association
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• v.13 no.1
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• pp.15-22
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• 2013

Recently, the korean statistical information service reported that the elder people aged over 65 years take 11 percentage point of all population, indicating that the hyper-elder era will advent shortly. As a result, there are remarkably increasing demands for providing self-organizable home agent system for elder people. Of the home agent system, the ubiquitous home service is known to be useful to overcome this problem. However, current ubiquitous home services limited to provide functional services, and it can be observed that there is lack of consideration for elder-support products which are closely interacted with elder people in the living situation. In this paper, we analyze senior aids products that can be combined to the ubiquitous home service, and propose design procedure for senior aids products that can be applied to self-organizable ubiquitous services. We studied characteristics of elder people, current state of affairs for senior aids products, and home services that are highly required by elder people. Moreover, we observed that the ubiquitous home services related to health, safety, and amenity are urgently needed, and those services can be categorized according to residential areas. Following those observances, we proposed a design principle based on the universal design paradigm to provide self-organizable ubiquitous home service environment for elder people using senior aids products.

• Journal of Intelligence and Information Systems
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• v.9 no.1
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• pp.109-123
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• 2003

The relationship between suppliers and customers is treated importantly not only in the traditional business-to-business (BtoB) commerce but also in today's Internet environments. On the one hand, most of Internet-based BtoB commerce services like customer-centric e-procurement, supplier-centric e-sales or intermediary-centric e-marketplace focus mainly on the selection of partners according to bidding, auction, etc. This point may result in the problem of overlooking the relationships between suppliers and customers. To overcome this problem in this paper, an intelligent agents-based supply chain operation architecture is proposed and appraised considering the relationship and its adaptation.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.12
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• pp.157-164
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• 2019

Superabsorbent polymers(SAPs) are powdery material that absorb water several tens or hundreds of times its own mass. It has been reported that when SAPs are incorporated into a high strength cementitious material, the autogenous shrinkage of the material is reduced. Cross-linked sodium polyacrylate type SAPs are relatively safe for human body and low in production cost. In order to apply this type of SAPs to the admixture for total(plastic+autogenous+drying) shrinkage reduction of high strength mortar, the shrinkage behavior of mortar when an expansion agent(EA) and SAPs were mixed together was analyzed. As a result, it was found that the shrinkage was reduced when an EA 5% (mass % of cement) and SAPs 0.4% were mixed together than the mortar containing only an EA 10%. The shrinkage was further reduced when EA 10% and SAPs 0.4% were incorporated into mortar.

• Asian Journal of Innovation and Policy
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• v.10 no.1
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• pp.132-154
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• 2021

A mega sport event as the globalization phenomenon is not only the symbol of the process of modernization but also the vehicle to upgrade global power and hold a dominant position in the world competition under the post-industrial era. This study notifies the role of mega sport events as a strategy for urban innovation in the context of global and local. Comparing the different roles of mega sport events between developing countries and developed countries, we intend to answer two questions: 1) what explains the nature and role of mega sport event, and 2) what are the major evidences of the transition in the globalization era. The conceptual framework, based on the temporal and spatial perspective, provides the mechanism through which the strategy for urban innovation has been changed from 'motivation for modernization' to 'rethinking of localization.' Focusing on the case of Seoul, we also compare major issues between two phases: role of agent, urban form, and urban development. Finally, this study sheds light on the concept of 'glocalization' which means the convergence of globalization and localization; and suggests the roles of (local) agent for hosting mega sport events.

• The Journal of Korea Robotics Society
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• v.18 no.4
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• pp.436-443
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• 2023

With the advancement of robot intelligence, the concept of man and unmanned teaming (MUM-T) has garnered considerable attention in military research. In this paper, we present a transformer-based architecture for predicting the health status of agents, with the help of multi-head attention mechanism to effectively capture the dynamic interaction between friendly and enemy forces. To this end, we first introduce a framework for generating a dataset of battlefield situations. These situations are simulated on a virtual simulator, allowing for a wide range of scenarios without any restrictions on the number of agents, their missions, or their actions. Then, we define the crucial elements for identifying the battlefield, with a specific emphasis on agents' status. The battlefield data is fed into the transformer architecture, with classification headers on top of the transformer encoding layers to categorize health status of agent. We conduct ablation tests to assess the significance of various factors in determining agents' health status in battlefield scenarios. We conduct 3-Fold corss validation and the experimental results demonstrate that our model achieves a prediction accuracy of over 98%. In addition, the performance of our model are compared with that of other models such as convolutional neural network (CNN) and multi layer perceptron (MLP), and the results establish the superiority of our model.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.10
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• pp.1081-1087
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• 2008

This paper describes limitations and solutions of the existing processor-monitoring concept for a military supersonics aircraft Flight Control Computer (FLCC) equipped with modern architecture processor to perform the system integration test. Safecritical FLCC integration test, which requires automatic test for thousands of test cases and real-time input/output test condition generation, depends on the processor-monitoring device called Processor Interface (PI). The PI, which relies upon on the FLCC processor's external address and data-bus data, has some limitations due to multi-fetching capability of the modern sophisticated military processors, like C6000's VLIW (Very-Long Instruction Word) architecture and PowerPC's Superscalar architecture. Several techniques for limitations were developed and proper monitoring approach was presented for modem processor-adopted FLCC system integration test.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.4
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• pp.243-248
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• 2005

The UAV (Unmanned Aerial Vehicle) systems like unmanned autonomous helicopters are used in various missions of flight navigation and used to collect the environmental information of the surroundings. To realize the full functionalities of the UAV, the software part becomes a challenging problem. In this paper embedded real-time software architecture for unmanned autonomous helicopter is proposed that guarantee real-time performance of hard-real time tasks and re-configurability of soft-real time and non-real time tasks. The proposed software architecture has four layers: hardware, execution, service agent and remote user interface layer according to the reactiveness level for external events. In addition, the layered separation of concurrent tasks makes different kinds of mission reconfiguration possible in the system. An Unmanned autonomous helicopter system was implemented (Kyosho RC Helicopter) in our lab to test and evaluate the performance of the proposed system.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.207-208
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• 2006

Intrusion detection technology is highlighted in order to establish a safe information-oriented environment. Intrusion detection system can be categorized into anomaly detection and misuse detection according to intrusion detection pattern. In this paper, we propose an architecture to make up for the defect of conventional anomaly intrusion detection. This architecture reduces additional resource consumption and cost by placing the agent in the strategic location in Internet.