• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.119-127
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• 2009

There have been about 450 atomic frequency standards (or atomic clocks) launched into orbit for the use on communications and scientific payloads since 1970's. GPS satellites carry on-board Rubidium and Cesium atomic frequency standards which are utilized for the precise positioning and timing. The evolving technologies of space qualified atomic frequency standards have enhanced in the performance, reliability, and lifetime of satellites. In this paper we describe the fundamentals and performance of the atomic frequency standards, and introduce the atomic frequency standards which are presently on-board various satellites systems. We also present the GPS time scale and its applications.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.202-205
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• 2006

Space design is a process of solving spatial problems to create and construct all kinds of human lives. It also bestows new values to a medium to induce human perception based on the relationships between 'human and space' surrounding people. Research on user behavior has several ultimate goals including understanding both individual behavior and the relations between the user and space from a more scientific and systematic perspective, predicting various phenomena that can happen between space and humans, and reflecting the results in space design. As user behavior that's once limited within given space is going through some changes due to the introduction of digital technologies, research on user behavior in today's space design should be newly illuminated in the aspects of organic relations. Space now works as a receptor communicating with the user and responding to user behavior, and user behavior once under one-sided influences from space becomes more diverse and active. The influences of user behavior, in turn, cause changes to space itself. Thus this study set out to suggest new directions in research on user behavior based on interactions between space and the user in space design.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.347-351
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• 2014

Planetary exploration rovers are likely to make a trip on a winding and sloping road of irregular surfaces to the destination in order to accomplish scientific missions. One of the key technologies for rovers is a suspension for traveling and performing exploration missions; the suspension is an essential area of technology for a stable movement of a rover. In this study, an 8-wheel suspension is designed to enable efficient climbing of slopes on a passage to the destination. For the two front wheels among the eight wheels, the moment at the pivot connecting two wheels is derived when the distance between the wheels and the torque of wheels are same. A test experiment was performed to compare the magnitude of moment according to the change in tilt angle and the position of the pivot. Finally, a suspension design considering the position of the pivot was proposed to enhance the hill-climbing performance.

• Journal of Multimedia Information System
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• v.1 no.2
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• pp.133-142
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• 2014

In the revised 2015 curriculum, it is emphasized that fostering of the students as the capable 'creativity-convergent' individuals can be achieved by offering them the opportunities to cultivate the basic knowledge in liberal arts, society and scientific technologies through schooling. While retaining the basic principle of 'fostering creative people', this fundamentally-reformed curriculum involves improvements in the elementary and middle school curriculums in response to the national and social demands in which active responses to the changes in the educational environments and amelioration of the problems posed in the field applications are required. Accordingly, a novel future-oriented curriculum is necessary for the classroom teaching, and to realize the goal, the 'Competence-oriented Social Multimedia Computer Network Curriculum' adopting the virtualization and the 'Bottom-up' methods has been proposed in this paper as a feasible and practical curriculum. Our curriculum will be compared with the recent Cisco high school curriculum and analyzed contemplating recent curriculums in US, UK, Japan and India. Two 1-year practice courses are examined to prove the validity of the proposed curriculum for a period of two years as a qualitative research project. The results of the comparative analysis will show that our proposed curriculum is superior to the Cisco high school curriculum in the aspects of economic feasibility and learning satisfaction.

• Journal of Multimedia Information System
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• v.5 no.1
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• pp.27-34
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• 2018

In recent years, with the blooming of Internet of Things (IoT) and Cloud Computing (CC), researchers have begun to discover new methods of technological support in all areas (e.g. health, transport, education, etc.). In this paper, in order to achieve a type of network that will provide more intelligent media-data transfer new technologies were studied. Additionally, we have been studied the use of various open source tools, such as CC analyzers and simulators. These tools are useful for studying the collection, the storage, the management, the processing, and the analysis of large volumes of data. The simulation platform which have been used for our research is CloudSim, which runs on Eclipse software. Thus, after measuring the network performance with CloudSim, we also use the Cooja emulator of the Contiki OS, with the aim to confirm and access more metrics and options. More specifically, we have implemented a network topology from a small section of the script of CloudSim with Cooja, so that we can test a single network segment. The results of our experimental procedure show that there are not duplicated packets received during the procedure. This research could be a start point for better and more efficient media data transmission.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.290-292
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• 2009

With advance in technologies for wireless sensor networks(WSNs), 2.4 GHz band has become gradually attractive due to increase in low-power wireless communication devices. Especially ZigBee(IEEE 802.15.4-based) technology whose frequency band includes the 2.4GHz industrial, scientific and medical band providing nearly worldwide availability has been universally applicable to a various remote monitoring system and applications related home network system. However network throughput of these systems is significantly deteriorated due to this ISM band is a license-exemption used in a variety of low-power wireless communication devices. For instance, other IEEE 802 wireless standards such as Bluetooth, WLAN, Wi-Fi and others cause radio interference to ZigBee. The experiments was carried out to analyze radio frequency interference between heterogeneous devices using ISM bands to improve the limited frequency utility factor. Finally this paper suggests a frequency hopping-based adaptive multi-channel methods to decrease interference with empirical results.

• International Journal of Advanced Culture Technology
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• v.2 no.1
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• pp.20-24
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• 2014

As the standards organization under ISO responsible for the development of all international financial services standards, ISO/TC 68 plays a key role in the development and adoption of new technologies in the banking, brokerage and insurance industries. In this paper many of its current work projects are introduced for developing ecommerce standards. We need to discuss the recommendations on XML conversion with ISO and other international standard organizations. Each country try to adopt the international standards even though domestic technical standards and barriers. To solve this problem of interworking between these standards, harmonization activities are nedded. For development and distribution of electronic documents to be conformed to international standards, it is enough to have the role of international activities continue to supply part of the domestic industry and the trends in participation and international standard.Our principal focus is on facilitating national and international trade, through the simplification and harmonization of processes, procedures and information flows, and so contributing to the growth of global commerce.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.425-427
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• 2010

Large-scaled information extraction consists of named-entity recognition, terminology extraction and relation extraction. Since all the elementary technologies have been studied independently so far, test collections for related machine learning models also have been constructed independently. As a result, it is difficult to handle scientific documents to extract both named-entities and technical terms at once. In this study, we integrate named-entities and terminologies with PLOT(Person, Location, Organization, Terminology) in a biomedical domain and construct a test collection of PLOT and relations between PLOTs.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.465-470
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• 2010

Korea government declared that "low carbon, green growth" through green technologies and clean energy to be the new national vision for the next 60 years(President's Liberation Day speech on Aug. 15, 2008). And succeeding "Green New Deal" plan involves nine core projects including energy saving, recycling, clean energy development. It is because hydrogen fuel cell vehicles, using electricity from chemical reaction of hydrogen and oxygen, let out water which is a by-product of such chemical reaction instead of emitting harmful particulate and gases such as NOX, SOX and CO2 that hydrogen fuel cell vehicles and its technology are drawing public attention as one of the sensible solutions in accomplishing "low carbon, green growth" agenda. Nevertheless There are many chances that let the people have a practical experience of hydrogen fuel cell vehicles. Sometimes new products, including hydrogen fuel cell vehicles, made by advanced technology can not penetrate through the market when it faces public skepticism that is stimulated from lack of knowledge and experience. That is the reason why not only cost benefit analyses and scientific risk assessments but also public acceptance studies toward hydrogen fuel cell vehicles have to be performed [Schulte, 2004]. This research address a need for comprehensive study on factors influencing public acceptance of hydrogen fuel cell car, specifically focusing on impacts of personal experience related to governmental science and technology policy toward public acceptance.

• STI Policy Review
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• v.4 no.2
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• pp.19-40
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• 2013

The Association of Southeast Asian Nations (ASEAN) achieved relatively rapid economic growth over the past decade. Sustainable growth among member states, however, is put into question due to macroeconomic challenges, political risk, and vulnerability to external shocks. Developed countries, in contrast, have turned into less labor-intensive technologies to further expand their economies. In this paper, we review the science, technology, and innovation (STI) policies and statuses of the scientific and technological capabilities of the ASEAN member countries. Empirical results based on STI indicators (R&D spending, publications, patents, and knowledge economy indices) reveal considerable variation between the science and technology (S&T) competence and effectiveness of STI policies of ASEAN members. We have categorized nations into clusters according their situations in their S&T productivity. Under the Korean Innovation Model, Cambodia, Laos, Myanmar, and Brunei are classified as being in the institutional-building stage, while Malaysia, Thailand, Indonesia, the Philippines, and Vietnam in the catch up stage, and Singapore in the post-catch up stage. Finally, policy prescriptions on how to enhance the S&T capabilities of the developing ASEAN countries, based on the South Korea development experience, are presented.