• Journal of Information Technology Applications and Management
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• v.22 no.3
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• pp.55-64
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• 2015

We propose statistical methods for evaluating the efficiency of CAPTCHA. Most people unfairly assumed that machines are not capable at reading precisely. This fact leads to the invention of CAPTCHA, a distorted word or short phase, which is designed to thwart computers and separate human from machines. However, advances in image recognition technologies mean that machines are constantly getting better at recognizing CAPTCHA. This forces CAPTCHA designers to design even more difficult CAPTCHAs to prevent their systems from being gamed by malicious bots. However, this arm race has an unintended side effect on the common users. Many CAPTCHAs are now so hard that many people are unable to read them. This obviously conflicts with the original purpose that CAPTCHA was invented in the first place. Our analysis shows that some CAPTCHAs are more users friendly. In particular, Yahoo-style CAPTCHA is the most friendliness. This suggests that a good CAPTCHA could be a simple text with some distortion that prevents machines from correctly segmenting characters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5419-5436
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• 2016

Enhancing the performance of computing systems has been an important topic since the invention of computers. The leading-edge technologies of multicore and virtualization dramatically influence the development of current IT systems. We study performance attributes of response time (RT), throughput, efficiency, and scalability of a virtualized Web system running on a multicore server. We build virtual machines (VMs) for a Web application, and use distributed stress tests to measure RTs and throughputs under varied combinations of virtual cores (VCs) and VM instances. Their gains, efficiencies and scalabilities are also computed and compared. Our experimental and analytic results indicate: 1) A system can perform and scale much better by adopting multiple single-VC VMs than by single multiple-VC VM. 2) The system capacity gain is proportional to the number of VM instances run, but not proportional to the number of VCs allocated in a VM. 3) A system with more VMs or VCs has higher physical CPU utilization, but lower vCPU utilization. 4) The maximum throughput gain is less than VM or VC gain. 5) Per-core computing efficiency does not correlate to the quality of VCs or VMs employed. The outcomes can provide valuable guidelines for selecting instance types provided by public Cloud providers and load balancing planning for Web systems.

• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.60-67
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• 2008

The spatial limitations of urban environments in general lead to invention and design of a wide range of underground transportation systems such as subways, underground roads and paths, etc. Among them, the application of subway systems in metropolitan cities is most commonly observed to ease those confronted difficulties on this purpose. It in turn leaves passengers and workers to be exposed to indoor air potentially polluted by various sources existing in this underground environment. Specifically when considering the IAQ in a subway station, there exist many IAQ-related parameters to be counted either as individual or as integrated exposures. In this study, a model system has been developed to manage the general IAQ in a subway station. Field survey and $CO_2$ measurements were initially conducted to analyze and understand the relationship between the indoor and outdoor air quality while considering the internal pollution sources such as passengers, subway trains, etc. The measurement data were then employed for the model development with other static information. For the model development, the algorithm of simple continuity was built and applied to model the subway IAQ concerned. In this paper, the recent updated draft version of model developed will be reported and demonstrated.

• Journal of the Korea Furniture Society
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• v.18 no.1
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• pp.56-69
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• 2007

As exchange and cooperation have increased in each country or region and a variety of NGOs are getting increasingly active in the 21st century, environments for the industry of international conventions have continued to improve. However, since the industry is in the starting stage, facilities for international conventions and professional management personnel are deficient. In this study, furniture design that shows the cultural identity of Korea from the invention facilities is focused and efforts are made in order to make the shape that has functionality and meaning based on the analysis of space. Participants of diverse nationalities, who use international convention facilities, feel Korea through furniture and remember its image; thus, this study focuses on the furniture design that has the identity of Korea. The concept of furniture design has been derived based on the traditional aesthetic consciousness in the symbolic, cultural, and emotional light. The identity of design does not depend on the partial characteristics of the traditional society but modernity and internationality shall coexist along with traditionality. Modernity and globalism are reflected along with the traditional elements in furniture.

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.41-58
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• 2008

The history of illumination has been much long since the discovery of lamplight caused huge changes in human lives. However, the swift development of the illumination actually started with the invention of a carbon filament lamp by Thomas Edison in 1878. Generally, the illumination tools plays important roles in human lives such as reduction of fatigue, improvement of safety and working efficiency, and the creation of enjoyable atmosphere. But, the illumination tools can be an origin of the fire due to carelessness and lack of management. In this study, the principle and structure of the illumination lamp were dealt with. The possibility of the fire outbreak caused by the incandescent lamp and fluorescent lamp most used in home was investigated. The examples of the fire outbreaks by the incandescent and fluorescent lamps and by the contact between the inflammable materials and the distributing wires were mentioned and demonstrated by the experimental.

• World Technopolis Review
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• v.4 no.3
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• pp.157-167
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• 2015

Innovation system is a framework concept that can be classified in many ways, namely-national, regional, sectoral and technological. Regardless of classification, all these systems have some common features and characteristics as a system. Before the innovation system concept, Mongolia developed and implemented a system to maintain nation's capacity to acquire, absorb and disseminate technologies like other countries. There were two important practices in the system development. Firstly, Mongolia modified and implemented a system "ShBOS" (meant "Invention and Innovative Idea System") that met its unique features to create innovative culture in the nation. Secondly, newly emerged ICT sector was quickly scaled up to be able to export technological products. The main objective of this article is to study modern experience of developing the national innovation system in Mongolia, assess current state of the system, innovation awareness and readiness, and carry out recommendations on its improvement with particular focus on the capacity of ICT sector as a pilot sector. The paper suggests that the above mentioned two achievements can be applied for developing the national innovation system through technological innovation system approach.

• International Journal of Contents
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• v.15 no.2
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• pp.1-12
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• 2019

Despite their various similarities, Seoul's' Gangnam and Seocho districts showed different patterns in the adoption of the RFID household-based waste charging system. Gangnam, one of the 25 wealthiest districts in Seoul, first adopted the RFID system in 2012, but decided abandon it a year later due to inconvenience, sanitation, budget limitations, and management related issues. Unlike Gangnam, Seocho, a largely similar district to Gangnam, started to implement the RFID system in 2015 and successfully adopted this innovation. In this paper, we explain the adoption behaviors of these two districts using a Technology Hype Curve Model with 5 stages. Unlike traditional technology adoption theory, the Hype Curve Model concentrates on the big chasm between early majorities and late majorities, which is a core reason for discontinuity in innovation diffusion. Based on our case study result, the early majority easily gave up adoption due to immature technological and institutional infrastructure. However, Seocho district, who waited until the deficiencies had been sufficiently fixed since late majorities, succeeded at incremental diffusion. Since its invention by Gartner cooperation, the Hype Curve Model has not received enough attention in academia. This paper demonstrates its explanatory power for innovation diffusion. Similarly, this paper focuses on the importance of institutional framework in the diffusion of innovation. Lastly, we compare the behavior of two local governments in supporting and diffusing RFID systems to draw relevant policy implications for innovation diffusion.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.383-390
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• 2015

In this study it placed the object of the present invention is to provide a more efficient user interface experience to analyze the structure information and the user experience when using the pattern of the search with the number of intended use of the smart phone. Naver and Daum were the results of the study will consist of 28 dogs and 15 each category Naver and Daum had both a top-down sequential structure. In the case of Naver it has raised the possibility of cognitive load through the use of duplicate content and excessive scrolling news Daum has been in the case of shopping categories at the bottom of this error was raised the possibility of using touch gestures.

• Journal of Astronomy and Space Sciences
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• v.28 no.3
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• pp.241-252
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• 2011

A simulated network protocol provides the capability of distributed simulation to a generic simulator. Through this, full coverage of management of data and service handling among separated simulators is achieved. The distributed simulation environment is much more conducive to handling simulation load balancing and hazard treatment than a standalone computer. According to the simulated network protocol, one simulator takes on the role of server and the other simulators take on the role of client, and client is controlled by server. The purpose of the simulated network protocol is to seamlessly connect multiple simulator instances into a single simulation environment. This paper presents the development of a simulated network (simNetwork) that provides the capability of distributed simulation to a generic simulator (GenSim), which is a software simulator of satellites that has been developed by the Korea Aerospace Research Institute since 2010, to use as a flight software validation bench for future satellite development.

• Information Systems Review
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• v.18 no.1
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• pp.41-55
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• 2016

This empirical study discusses the current status and future directions of the SME informatization project based on cloud computing technology. Launched by the Korea Technology and Information Promotion Agency for SMEs in 2013, the project started with the exemplar support of seven cooperatives in the industry. Currently, understanding past usage patterns and user expectations is imperative in developing future strategies and implementation plans. We determined that user satisfaction and expectations are different between the generic basic solutions and the industry-specific solutions embedded in the industry-specific business processes. We propose several strategies on how to coordinate market concerns about government invention on the cloud software market and government support to invigorate the use of computer systems among SMEs.