• Journal of Institute of Control, Robotics and Systems
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• v.22 no.11
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• pp.967-976
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• 2016

This paper presents a 3D carrier-smoothed GNSS/DR (Global Navigation Satellite System/Dead Reckoning) integrated system for precise ground-vehicle trajectory estimation. For precise DR navigation on sloping roads, the AHRS (Attitude Heading Reference System) methodology is employed. By combining the integrated carrier phase of GNSS and DR sensor measurements, a vehicle trajectory with an accuracy of less than 20cm is obtained even when cycle slip or change of visibility occur. In order to supplement the weak GNSS environment with DR successfully, the DR sensor is precisely compensated for using GNSS Doppler measurements when GNSS visibility is good. By integrating a multi-GNSS receiver with low-cost IMU, a precise 3D navigation system for land vehicles is proposed in this paper. For real-time implementation, a decoupled Kalman filter is employed in the integrated system. Through field experiments, the performance of the proposed system is verified in various road environments, including sloping roads, good-visibility areas, high multi-path areas, and under-ground parking areas.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.119-127
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• 2009

Even though there are next generation Global Navigation Systems in development, only GPS and GLONASS are currently available for satellite positioning. In this study, GLONASS orbits were predicted using Keplerian elements in almanac and the orbit equation. For accuracy validation, predicted orbits were compared with precise ephemeris. As a result, the 3-D maximum and RMS (Root Mean Square) errors were 155.4 km and 56.3 km for 7-day predictions. Also, the GLONASS satellite visibility predictions were compared with real observations, and they agree perfectly except for several epochs when the satellite signal was blocked nearby buildings.

• Journal of Astronomy and Space Sciences
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• v.26 no.2
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• pp.199-210
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• 2009

Even though there are several Global Navigation Satellite Systems under development, only GPS and GLONASS are currently available for satellite positioning. In this study, GLONASS orbits were predicted from broadcast ephemeris using the 4th-order Runge-Kutta numerical integration. For accuracy validation, predicted orbits were compared with precise ephemeris. The RMS(Root Mean Square) and maximum 3-D errors were 14.3 km and 17.4 km for one-day predictions. In case of 7-day predictions, the RMS and maximum 3-D errors were 15.7 and 40.1 km, respectively. Also, the GLONASS satellite visibility predictions were compared with real observations, and they agree perfectly except for several epochs when the satellite signal was blocked by nearby buildings.

• Korean Institute of Interior Design Journal
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• no.21
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• pp.42-53
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• 1999

The purpose of this study is to clarify the relationship between the exhibits layout and the spatial organization in exhibition spaces. As an analytical method, the space syntax theory devised by Bill Hillier(1984) was applied for analysing the potential differentiation of exhibition spaces and remodeling method in Seoul City Museum selected for case study. The results are as following. Especially from the convex analysis, axial analysis and exhibits(interpretation); 1) the closed spatial system(1F) has high visibility and high intelligibility in hall area but lacks route continuity, 2) the circulated spatial system(2F) has low global visibility but offers high intelligibility and connectivity due to its coercive circulation, 3) and the organization of exhibition design consists in differentiating space that reintegrates them into another spatial order. Therefore, there process are expected to provide a methodological framework for analysing and interpreting spatial organizations of design, leading to the clear explanation of remodeling.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.5
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• pp.81-93
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• 2015

It is very difficult that a company could grow with its own competitiveness in modern global competition era. The pattern of competition is changing from company-to-company to supply chain network-to-supply chain network. In order to enhance competitiveness and survive capability by combining inter-enterprises core competencies, the effort to integrate and optimize supply chain are increasing. The purpose of this study was to specify the effects of SCM characteristics on supply chain partnership and corporate performance through corporate characteristics such as agility and visibility. So as to verify hypotheses, multiple regression analysis was performed by using SPSS statistical package. The results showed that SCM characteristics had the positive effect on agility and visibility, and supply chain partnership and corporate performance was statistically influenced by agility and visibility. This study contributes on the SCM related research in that it investigated SCM activities of construction machinery industry.

• Journal of Surface Science and Engineering
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• v.56 no.2
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• pp.152-159
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• 2023

The night visibility of pavement is being considered as a global issue in the field of traffic safety. Although the spreading glass beads on the lane paints has been mainly used to secure night-visibility by utilizing the effect of retroreflection, obvious shortcoming of this method is that retroflection does not occur in the range where the headlights do not reach the glass beads. The use of functional paints including phosphorescent constituents could be a solution for overcoming fore-mentioned problem. SrAl₂O₄ based chemicals have not only good phosphorescent property, but also are chemically stable compared to existing ZnS based materials. However, this chemicals also need the improvement due to slightly reduced luminous effect in time. Herein, we developed novel paints showing enhanced phosphorescent properties by putting rare earth elements such as Eu, Dy and Y into SrAl₂O₄. These prepared phosphorescent pigments have displayed improved properties in terms of durability and long afterglow. For instance, the property of afterglow has been persisted after 5 hours with luminace of 20.6 mcd/m².

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1207-1214
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• 2014

Recently it has become easier to figure out cargo positional information by using GPS(Global Positioning System) and wireless communication technology. The acceleration of globalization in the shipping logistics is ever more increasing the need to provide visibility, traceability and real time informations of entry, departure of vessel including cargo and status of logistic vehicle entry into each logistic base. Providing such positional information to logistics party by using wireless communication technology can bring effective operation of supply chain and reduction in logistics costs. In the previous paper, I suggested a global location tracking system based on GPS data in global shipping logistics by means of software using GPS data. However, the previous system had a problem of being inadequate to figure out a real time location movement information and was unsatisfactory on quickly searching and checking the location of global logistics hubs according to the longitude and latitude coordinates. Hence, in this paper, I suggest a real-time location tracking system that provided real-time location of the container cargos and logistics hubs can be searched quickly according to the GPS coordinates in global shipping logistics.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.6
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• pp.779-788
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• 2016

In this paper, a global path replanning method is proposed in order to plan a global path minimizing the risk of the unmanned vehicle on the battlefield. We first introduce 4D environmental information consisting of mobility, visibility, kill, and hit attributes, and a unified threat map and a mobility map are defined by the four attributes. Using the mobility map, the unmanned vehicle can find the shortest path on the traversable area. And then taking into account the deterrent according to the type of the unmanned vehicle on the integrated threat map, the vehicle can generate a route to suppress or avoid the threat of enemy as well. Moreover, we present a waypoints bypassing method to exclude unnecessary waypoints rather than the mission point when planning paths for the multiple waypoints.

• STI Policy Review
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• v.1 no.3
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• pp.17-24
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• 2010

Energy consumption is the largest contributing factor for the increase of $CO_2$ emissions and amounts for almost 85% of all emissions. The future energy consumption of Korea is projected to grow exponentially despite its heavy dependence on imported energy that represents 97% of its total energy supply. According to a recent OECD report the carbon emission level of Korea is currently ranked 9th in $CO_2$ emissions, and is growing by almost 3% every year. Against this background, the Korean government introduced the "low carbon green growth" policy in 2008. As the global challenges intensified in the wake of the world economic crisis, Korea has been working hard in raising the visibility of its efforts at the club governance meetings, in particular the G-20 summit. Because of cooperative efforts with major member countries, the G-20 summit agenda has been significantly diversified to include long-term issues such as climate change, development issues, and global health. To achieve an effective green recovery for a new green world economic order, the G-20 summit leaders should concentrate on a strategy of establishing green governance for a global STI cooperation. Korea as the host country is poised to leverage the Seoul G-20 summit to catalyze global efforts toward a new green economic order.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.2
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• pp.101-108
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• 2015

In this paper, a robust traffic light detection method is proposed by using vision sensor and DGPS(Difference Global Positioning System). The conventional vision-based detection methods are very sensitive to illumination change, for instance, low visibility at night time or highly reflection by bright light. To solve these limitations in visual sensor, DGPS is incorporated to determine the location and shape of traffic lights which are available from traffic light database. Furthermore the geometric relationship between traffic light and vision sensor is used to locate the traffic light in the image by using DGPS information. The empirical results show that the proposed method improves by 51% in detection rate for night time with marginal improvement in daytime environment.