• Journal of Appropriate Technology
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• v.6 no.2
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• pp.126-135
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• 2020

Recently, with the development of the 4th Industrial Revolution era and the popularization of technologies the maker movement is spreading worldwide in various ways for education, entrepreneurship, and solving social problems. This paper introduces a case of establishing and operating a maker space in Tanzania, East Africa, one of the developing countries. iTEC Tech-shop was established in the first half of 2018 at the Nelson Mandela African Institution of Science and Technology (NM-AIST) in Arusha, Tanzania by Innovative Technology and Energy Center (iTEC), and has been operating for nearly two years. With the allocation of empty warehouse space from NM-AIST, physical facilities were established through the purchase and installation of equipment and hand tools. Based on the advice from Idea Factory of Seoul National University and Fab-Lab Seoul, iTEC Tech-shop operational system were established. Through a total of 7 technical workshops, iTEC Tech-shop provided training courses for about 180 local personnel. In addition, the smart Techshop test-bed project was promoted in order to improve the operation level along with securing sustainability of the Techshop. The case of the iTEC Tech-shop could be a useful case for institutions or organizations promoting the maker movement to developing countries.

• Journal of Korean Society of Steel Construction
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• v.14 no.3
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• pp.463-470
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• 2002

The TEC-Beam system is a composite beam consisting of structural tee, precast concrete, and cast-in-site reinforced concrete slab. The preliminary test of the proposed system was performed for simple beams, showing good behavior. However, for the field application of the system. TEC-Beam - RC column connection was required to produce a mechanism that transfers the force occurring in the lower part of the TEC-Beam. Thus, this study developed a connection mechanism that transfers the force occurring in the lower part of the TEC-Beam. Thus, this study developed a connection wherein the section of the TEC-Beam was enlarged and the lower part reinforced. Two setups of the proposed system were experimentally investigated. using the anchorage length of reinforcement., i.e., length of the increased section, as test parameter. It could be concluded from the result that the proposed system shows good structural behavior, with potential applicability in the field.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.228-235
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• 2016

We investigated pre- and post- seismic total electron content (TEC) anomalies in ionosphere caused by recent large-scale earthquakes around the globe and additionally examined whether the similar phenomena are detected in connection with the earthquakes around the Korean Penisula. TEC anomalies associated with the large-scale earthquakes showed the similar results to previous studies. In addition, we newly found the similar TEC changes from the recent 2016 Ecuador earthquake (M7.8). However, the post-seismic TEC changes would be falsely interpreted as the pre-seismic TEC changes dependent on the post-processing of TEC observation. We also investigated the possibility of TEC responses from the recent domestic earthquakes including 2016 Gyeongju earthquake but could not find any anomalous TEC changes. This is probably because the domestic earthquakes release significantly smaller acoustic wave energy than that of large-scale earthquakes occurring in plate boundaries.

• Journal of Astronomy and Space Sciences
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• v.37 no.1
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• pp.61-68
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• 2020

Recent studies have suggested that detectable ionospheric disturbances precede earthquakes. In the present study, variations in the vertical total electron content (TEC) for eight earthquakes with magnitudes of M ≥ 5.5 in the western United States were investigated during the solar maximum of 2013-2015 using United States total electron content (US-TEC) data provided by the National Oceanic and Atmospheric Administration. Analyses of 12 earthquakes with magnitudes of 5.0 ≤ M < 5.5 in the same region were also performed. The TEC variations were examined for 40 days, including the times when the earthquakes occurred. The results indicated a correlation between earthquakes with magnitudes of M ≥ 5.0 and ionospheric TEC anomalies. TEC anomalies occurred before 60% of the earthquakes. Additionally, they were more frequently observed for large earthquakes (75%, M ≥ 5.5) than for small earthquakes (50%, 5.5 > M ≥ 5.0). Anomalous increases in the TEC occurred 2-18 days before the earthquakes as an ionospheric precursor, whereas solar and geomagnetic activities were low or moderate.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.3
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• pp.175-181
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• 2018

The use of dual-frequency measurements from the Global Navigation Satellite System (GNSS) enables us to observe precise ionospheric total electron content (TEC). Currently, many GNSS reference stations in South Korea provide both GPS and GLONASS data. In the present study, we estimated the grid-based TEC values and relative receiver differential code biases (DCB) from a GNSS network operated by the Korea Astronomy and Space Science Institute. In addition, we compared the diurnal variations in a TEC time series from solutions of the GPS only, the GLONASS only, and combined GPS/GLONASS processing. A significant difference between the GPS only TEC and combined GPS/GLONASS TEC at a specific grid point over South Korea appeared near the solar terminator. It is noted that GLONASS measurements can contribute to observing a variation in ionospheric TEC over high latitude regions.

• Genomics & Informatics
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• v.12 no.2
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• pp.58-63
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• 2014

The tyrosine-protein kinase Tec (TEC) is a member of non-receptor tyrosine kinases and has critical roles in cell signaling transmission, calcium mobilization, gene expression, and transformation. TEC is also involved in various immune responses, such as mast cell activation. Therefore, we hypothesized that TEC polymorphisms might be involved in aspirin-exacerbated respiratory disease (AERD) pathogenesis. We genotyped 38 TEC single nucleotide polymorphisms in a total of 592 subjects, which comprised 163 AERD cases and 429 aspirin-tolerant asthma controls. Logistic regression analysis was performed to examine the associations between TEC polymorphisms and the risk of AERD in a Korean population. The results revealed that TEC polymorphisms and major haplotypes were not associated with the risk of AERD. In another regression analysis for the fall rate of forced expiratory volume in 1 second ($FEV_1$) by aspirin provocation, two variations (rs7664091 and rs12500534) and one haplotype (TEC_BL2_ht4) showed nominal associations with $FEV_1$ decline (p=0.03-0.04). However, the association signals were not retained after performing corrections for multiple testing. Despite TEC playing an important role in immune responses, the results from the present study suggest that TEC polymorphisms do not affect AERD susceptibility. Findings from the present study might contribute to the genetic etiology of AERD pathogenesis.

• MALSORI
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• no.46
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• pp.175-185
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• 2003

To support speech information technology industry it is vital to create and distribute standardized speech corpora to be used for the development of products and technologies. In this article we introduce speech corpora created by Speech Information Technology & Industry Promotion Center(SiTEC) during its 1st and 2nd fiscal years (2001/5/1-2003/4/30) and plans for those corpora which is being created currently or will be created in near future. We introduce the corpus for car application to expand speech information technology to the field of traditional industry, the corpora for foreign languages to support exportation, the corpus for basic research for the sake of application in the industry, the corpora for common use, and others.

• Journal of Astronomy and Space Sciences
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• v.16 no.2
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• pp.285-292
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• 1999

To determine a geographical position by GPS signal, the effect of the ionosphere must be considered to improve accuracy. This has led us to continuously try to find the TEC of the ionosphere by using the GPS signal. So far the way to find TEC has been developed and the information obtained from this can be used not only to increase the accuracy of determining the position, but also to study the ionosphere. In this research, the TEC MAP over Korea was obtained by using the data collected from eight GPS stations around the Far East Asia, which is the common way to represent TEC over some regional or global region.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.3
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• pp.157-161
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• 2022

The Nuri rocket developed by South Korea was launched at approximately 07:00 UT on June 21, 2022. We use GPS observations obtained from the Korean GNSS network to analyze ionospheric total electron content (TEC) disturbances induced by the 2022 Nuri rocket launch. TEC disturbances are observed south over South Korea 4-5 min after the rocket launch. In addition, the maximum depletion in the vertical TEC shows approximately 8 TEC units (TECU). We also compute a horizontal velocity from initial ionospheric disturbances triggered by the 2022 Nuri rocket launch. Its velocity is about 1.4 km/s. It may be related to the rocket's flight trajectory at the observation time of the ionospheric TEC disturbance.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.161-162
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• 2005