• Journal of Astronomy and Space Sciences
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• v.33 no.1
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• pp.45-54
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• 2016

This study developed an approach for improving Carrier-phase Differential Global Positioning System (CDGPS) based realtime satellite relative navigation by applying laser baseline measurement data. The robustness against the space operational environment was considered, and a Synthetic Wavelength Interferometer (SWI) algorithm based on a femtosecond laser measurement model was developed. The phase differences between two laser wavelengths were combined to measure precise distance. Generated laser data were used to improve estimation accuracy for the float ambiguity of CDGPS data. Relative navigation simulations in real-time were performed using the extended Kalman filter algorithm. The GPS and laser-combined relative navigation accuracy was compared with GPS-only relative navigation solutions to determine the impact of laser data on relative navigation. In numerical simulations, the success rate of integer ambiguity resolution increased when laser data was added to GPS data. The relative navigational errors also improved five-fold and two-fold, relative to the GPS-only error, for 250 m and 5 km initial relative distances, respectively. The methodology developed in this study is suitable for application to future satellite formation-flying missions.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.69-87
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• 2007

High-tech industries in Taiwan exist in an environment with diverse product requirements and intense cost reduction and information integration stress. They must develop new operational directions to increase industry competitiveness. Therefore, Taiwan's high-tech industries must continue R&D and creativity, establish knowledge sharing mechanisms and improve new product development (NPD) performance. This research analyzed and explored the influences of knowledge management (KM) and knowledge sharing mechanisms introduced by Taiwan's high-tech industries on new product development performance. The relationship between knowledge management capabilities and NPD performance is studied. This research considers the intervening industry and corporate position variables. Taiwan's high-tech industries have gradually entered the era of IT region integration and application with competitive advantage creation based upon core techniques. The in-depth study of knowledge management and knowledge sharing introduced by the high-tech industry revealed double meanings in academic and practical applications. The research results showed the following: (1) the stronger the knowledge management capabilities of Taiwan's high-tech industries, the more significant the NPD performance. (2) The better the knowledge sharing mechanism in Taiwan's high-tech industries, the more significant the NPD performance. (3) Corporate scale is not necessarily the critical factor in NPD success and the influence of corporate scale on NPD performance did not show significant differences. (4) The stronger the degree of leading corporate techniques, the more significant the NPD performance.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.4
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• pp.264-274
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• 2009

Concentration of Air Quality Models (CMAQ) has a deep connection with emissions and wind fields. In particular the wind field is highly affected by local topography and plays an important role in transport and dispersion of contaminants from the pollution sources. The purpose of this study is to examine the impact of interpolation on Air quality model. This study was designed to evaluate enhancement of MM5 and CMAQ predictions by using Four Dimensional Data Assimilation (FDDA), the SONDE data and the national meteorological station and the MODerate resolution Imaging Spectroradiometer (MODIS). The alternative meteorological fields predicted with and without MODIS data were used to simulate spatial and temporal variations of ozone in combined with CMAQ on June 2006. The result of this study indicated that data assimilation using MODIS data provided an attractive method for generating realistic meteorological fields and dispersion fields of ozone in the Korea peninsular, because MODIS data in 10 km domain are grid horizontally and vertically. In order to ensure the success of Air quality model, it is necessary to FDDA using MODIS data.

• Journal of Astronomy and Space Sciences
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• v.32 no.3
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• pp.257-268
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• 2015

Characteristics of delta-V requirements for deploying an impactor from a mother-ship at different orbital altitudes are analyzed in order to prepare for a future lunar CubeSat impactor mission. A mother-ship is assumed to be orbiting the moon with a circular orbit at a 90 deg inclination and having 50, 100, 150, 200 km altitudes. Critical design parameters that are directly related to the success of the impactor mission are also analyzed including deploy directions, CubeSat flight time, impact velocity, and associated impact angles. Based on derived delta-V requirements, required thruster burn time and fuel mass are analyzed by adapting four different miniaturized commercial onboard thrusters currently developed for CubeSat applications. As a result, CubeSat impact trajectories as well as thruster burn characteristics deployed at different orbital altitudes are found to satisfy the mission objectives. It is concluded that thrust burn time should considered as the more critical design parameter than the required fuel mass when deducing the onboard propulsion system requirements. Results provided through this work will be helpful in further detailed system definition and design activities for future lunar missions with a CubeSat-based payload.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.755-770
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• 2006

1974. 8.15 SeoulMetro, beginning with the first electric railway established at six cities, so it is managing mass transportation of traffic. Especially, in case of seoul, It is managing that from one to eight lines, 286.9km, 265 stations have installed and now it is carrying about 5.5million of passengers everyday, and 2,000million passengers a year. So accident is increasing from the station every year. For this measure, SeoulMetro prepares safety fence for passengers crash but, as suicides or people who watch the accident took place, for at the bottom of passengers crash protection, PSD installing is needed. Even though, PSD is managing ATO section but, in controlling SeoulMetro, one to four lines sections are (ATS, ATC)section. Between as ATS, ATC section, ATO section, subway gate and PSD must have opened and crossed always at the time. And the interlock control corrosion protection gate, managing skills with installation, method, using in history, apply to 10rail cars one train sets, and maximum applying 224% sections of passengers congested that consideration is to be needed. So 2004, SeoulMetro improved technology and basic design of PSD at ATS section. Based on this, from 2005.4 to 2006.6, using subway 2lines per 12stations set the model installation(full type 11stations, half type 1station) After installing in case of success, it is going about to suggest that effective analysis and hereafter subject.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.9
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• pp.70-75
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• 2021

We developed a platform that was capable of autonomous steering in a furrow environment. It was developed to autonomously control steering by recognizing the furrow using a laser distance, three-axis tilt, and temperature sensor. The performance evaluation indicated that the autonomous steering success rate was 99.17%, and it was possible to climb up to 5° on the slope. The usage time was approximately 40 h, and the maximum speed was 6.7 km/h.

• Journal of Apiculture
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• v.34 no.4
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• pp.285-293
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• 2019

The honey bee queen shows extreme polyandry and controlling the mating partners can only be possible either by artificial insemination or having remote isolated mating locations. Here we report on the German North Sea island of Heligoland. Because of its location 60 km from the mainland, the lack of a local population of honey bees, its size of just 1.4 ㎢ and suitable weather conditions during the months of May to July, it is considered an ideal location for controlled inseminations of high-quality virgin queen bees with drones deemed genetically superior to others. Methods how to rear virgin queen bees are described and information is provided on the numbers of queen bees, their supporting workers and drone bees that are taken to the island in the mating season. The bee most commonly involved in the Heligoland mating trials has become Apis mellifera carnica strain "Baltica". In one summer, for example, 80 virgin queens (belonging to beekeepers from nine different locations in northern Germany) each with about 600 worker bees plus two drone populations of around 2,000 drones were taken by ship to Heligoland. On their return to the mainland no later than 3.5 weeks after the mating exercise, the beekeepers could register a mating success rate of 80%. This information can help operation management of the new remote mating centre of Weedo Island, Jeonbuk in Korea, which is currently under construction.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.794-799
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• 2009

The temperature control of in-place concrete is the most important factor for an early age of curing concrete. Heat stress of mass concrete caused by the heat of hydration can induce the crack of concrete, and a frost damage from cold weather casting concrete results defect on compressive strength and degradation of durability. Therefore, success and failure of concrete work is dependant on the measurement and control of concrete temperature. In addition, the compressive strength assessment of in-place concrete obtained from the maturity calculated from the history of temperature make a reduction of construction cycle time, possible. For that purpose, wireless temperature measuring system was developed to control temperature and assess strength of concrete. And, it was possible to monitor the temperature of concrete over 1km apart from site office and to take a proper measure; mesh-type network was developed for wireless sensor. Furthermore, curing control system that contains the program capable to calculate the maturity of concrete from the history of temperature and to assess the compressive strength of concrete was established. In this study, organization and practical method of developed curing control system are presented; base on in-place application case.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.438-447
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• 2015

When communities of practice(CoP) was mostly informal, has been formulated. Because Knowledge management(KM) was emphasized in the business sector. So it increase interest in the COP. Since the early 2000s, the research interest has thus far grown. At a point in time has the subject, CoP, been researched for ten years, it is significant to review the literatures, the main topics as well as critical factors on the subject. In this study, the trends in the relevant researches and the performance factors from the previous studies are examined. The references for this study are limited to the authorized scholarly and scientific journals. The results therethrough processed show that total 37 researches were conducted between the year 2000 and 2012. These could be classified by the research methods as 16 case studies, 11 studies using CoP as the dependent variable, 4 studies using CoP as an independent variable and 3 theoretical discourses. 7 out of 16 case studies suggest the 14 success factors of CoP; the most influential performance factor is the external community support. 11 studies examined factors influencing the performance of CoP; 13 performance factors were proposed in these studies. The most significant factor influencing the performance of CoP is the team effectiveness.

• Korean Journal of Ichthyology
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• v.31 no.2
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• pp.67-76
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• 2019

This study was conducted from 2017 to 2018 to determine habitat aspects of Acheilognathus signifier, an endangered species reintroduced (2010~2012) to Heukcheon Stream, a tributary of the Hangang River, Korea. A total of 329 individuals were collected in 2017 (two surveys) and 723 individuals were collected in 2018 (four surveys) at about 5 km habitat area, including the discharge station. A. signifier's habitat was about 0.4 to 1.2 meters deep in slow water flow upstream of the discharge area. It was a place with many boulders and cobbles. The spawning period was estimated from April to June in terms of spawning behavior and collected juvenile size. Sex ratio of females (438) and males (412) was 1 : 0.94. Estimated age of A. signifier based on their total length distribution during the spawning period (April) indicated that 1-, 2-, 3-year old groups and more than 4-year-old group were 32~43 mm, 50~61 mm, 62~75 mm, and 76~89 mm, respectively. Age-specific composition costs differed depending on the timing of the collection. They were relatively high in the order of first-year (juvenile)>third-year> and fourth-year or higher, showing a stable age structure. Thus, A. signifier reintroduced to Heukcheon Stream has successfully settled down and formed a stable population, showing a tendency to proliferate.