• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.277-282
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• 2006

It is well known that Kalman filtering is an optimal real-time data fusion method for GPS/INS integration. However, it has some limitations in terms of stability, adaptability and observability. A Kalman filter can perform optimally only when its dynamic model is correctly defined and the noise statistics for the measurement and process are completely known. It is found that estimated Kalman filter states could be influenced by several factors, including vehicle dynamic variations, filter tuning results, and environment changes, etc., which are difficult to model. Neural networks can map input-output relationships without apriori knowledge about them; hence a proper designed neural network is capable of learning and extracting these complex relationships with enough training. This paper presents a GPS/INS integrated system that combines Kalman filtering and neural network algorithms to improve navigation solutions during GPS outages. An Extended Kalman filter estimates INS measurement errors, plus position, velocity and attitude errors etc. Kalman filter states, and gives precise navigation solutions while GPS signals are available. At the same time, a multi-layer neural network is trained to map the vehicle dynamics with corresponding Kalman filter states, at the same rate of measurement update. After the output of the neural network meets a similarity threshold, it can be used to correct INS measurements when no GPS measurements are available. Selecting suitable inputs and outputs of the neural network is critical for this hybrid method. Detailed analysis unveils that some Kalman filter states are highly correlated with vehicle dynamic variations. The filter states that heavily impact system navigation solutions are selected as the neural network outputs. The principle of this hybrid method and the neural network design are presented. Field test data are processed to evaluate the performance of the proposed method.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.19-26
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• 2005

Digital technology continually makes a space evolves. The real-time behavior design communicates the data with the situation of circumference of the space(visitors moving, interior and exterior situations). The space form was changed because it interfaces in real time. The purpose of this study was finding out the characteristics of real-time behavior space design through the analysis of space formative languages, sensorium, S-R and material. This study will be the one of basic references for the digital space design. The boundary of this study set limits to the works of digital space designer who applies the real-time exchanging data to their design among the digital space design works from 1996 to 2004. But it excepted from the real-time behavior space in virtual realty. Therefore, the objects of this study were the works of onl and NOX(paraSITE, Trans-port 2001, Muscle, MotormeCCa, Handdrawspace, Saltwater Pavilion, Son-O-House, H2O Expo). The method was the contents analysis of space formative languages(Greg Lynn's ten space formative languages; bleb, blob, branch, flower, fold, lattice, teeth, shred, skins and strand), sensorium, S-R and material. The results of the study are as follows: 1) The organizational elements; Space formative languages(bleb, blob, fold, shred, skins, strand), stimulation(Human Participation, Human Moving, Weather Conditions), and response(Spatial Moving, Sound Pattern, Lighting Pattern, color Pattern, Activating Particles, Moving Picture, Virtual Friend) 2) The material Use; Sound, lights, and network have been used in the space. Immaterial matter will be used the main material of space design in 21"'century, 3)The spatial types; formal changing of space, projecting immaterial elements, and changing the sound.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.45-54
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• 2008

This paper designs and Implements a connectivity analyzer for the hybrid vehicular network based on the real-life movement history data achieved from the Taxi telematics system currently in operation, aiming at providing a useful guideline and information to build a telematics network. The simulator traces the location of each vehicle, sets the vehicle type, either gateway or normal, decides whether it can be connected to a mobile gateway, keeps track of status of the vehicle, and calculates the duration of disconnected state. With this analysis considering the transmission range and gateway ratio, we can decide the cost-effective number of mobile gateways having both cellular and ad-hoc network interfaces, and buffer space requirement based on the measured disconnection time and message generation ratio.

• Journal of Communications and Networks
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• v.11 no.3
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• pp.287-296
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• 2009

Although asymptotic bounds of wireless network capacity have been heavily pursued, the answers to the following questions are still critical for network planning, protocol and architecture design: Given a three-dimensional (3D) network space with the number of active users randomly located in the space and using the wireless communication technology, what are the expected per-flow throughput, network capacity, and network transport capacity? In addition, how can the protocol parameters be tuned to enhance network performance? In this paper, we focus on the ultra wideband (UWB) based wireless personal area networks (WPANs) and provide answers to these questions, considering the salient features of UWB communications, i.e., low transmission/interference power level, accurate ranging capability, etc. Specifically, we demonstrate how to explore the spatial multiplexing gain of UWB networks by allowing appropriate concurrent transmissions. Given 3D space and the number of active users, we derive the expected number of concurrent transmissions, network capacity and transport capacity of the UWB network. The results reveal the main factors affecting network (transport) capacity, and how to determine the best protocol parameters, e.g., exclusive region size, in order to maximize the capacity. Extensive simulation results are given to validate the analytical results.

• Ocean and Polar Research
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• v.27 no.2
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• pp.189-195
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• 2005

Several models predict large and potentially abrupt ocean circulation changes due to anthropogenic greenhouse-gas emissions. These circulation changes drive-in the models-considerable oceanic oxygen trend. A sound estimate of the observed oxygen trends can hence be a powerful tool to constrain predictions of future changes in oceanic deepwater formation, heat and carbon dioxide uptake. Estimating decadal scale oxygen trends is, however, a nontrivial task and previous studies have come to contradicting conclusions. One key potential problem is that changes in the historical observation network might introduce considerable errors. Here we estimate the likely magnitude of these errors for a subset of the available observations in the Southern Ocean. We test three common data analysis methods south of Australia and focus on the decadal-scale trends between the 1970's and the 1990's. Specifically, we estimate errors due to sparsely sampled observations using a known signal (the time invariant, temporally averaged, World Ocean Atlas 2001) as a negative control. The crossover analysis and the objective analysis methods are for less prone to spatial sampling location biases than the area averaging method. Subject to numerous caveats, we find that errors due to sparse sampling for the area averaging method are on the order of several micro-moles $kg^{-1}$. for the crossover and the objective analysis method, these errors are much smaller. For the analyzed example, the biases due to changes in the spatial design of the historical observation network are relatively small compared to the tends predicted by many model simulations. This raises the possibility to use historic oxygen trends to constrain model simulations, even in sparsely sampled ocean basins.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.3-11
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• 2015

This paper aims to review and discuss a graph-based approach for the representation and analysis of building circulation using BIM models. To propose this approach, the authors survey diverse researches and developments which are related to building circulation issues such as circulation requirements in Korea Building Act, spatial network analysis, as well as BIM applications. As the basis of this paper, UCN (Universal Circulation Network) is the main reference of the research, and the major goal of this paper is to extend the coverage of UCN with additional features we examined in the survey. In this paper we restructured two major perspectives on top of UCN: 1) finding major factors of graph-based circulation analysis based on UCN and 2) restructuring the UCN approach and others for adjusting to Korean Building Act. As a result of the further studies in this paper, two major additions have demonstrated in the article: 1) the most remote point-based circulation representation, and 2) virtual space-based circulation analysis.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.6
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• pp.3-14
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• 2018

The aim of this study is to propose a method for calculating the weight of walking energy in ERAM model by calculating it for the analysis of vertical and horizontal spaces in a building. Conventional theories on the space analysis in the field of architectural planning predict the pedestrian volume of network spaces in urban street or in two-dimensional plane within a building, however, for vertical and horizontal spaces in a building, estimates of the pedestrian volume by those theories are limited. Because in the spatial syntax and ERAM model have been applied weights such as the spatial depth, adjacent angles, and physical distances available only to the two-dimensional same layer or plane. Therefore, the following basic assumptions and analysis conditions in this study were established for deriving a predictor of pedestrian volume in vertical and horizontal spaces of a building. The basic premise of space analysis is not to address the relationship between the pedestrian volume and the spatial structure itself but to the properties of spatial structure connection that human beings experience. The analysis conditions in three-dimensional spaces are as follows : 1) Measurement units should be standardized on the same scale, and 2) The connection characteristics between spaces should influence the accessibility of human beings. In this regard, a factor of walking energy has the attributes to analyze the connection of vertical and horizontal spaces and satisfies the analysis conditions presented in this study. This study has two implications. First, this study has shown how to quantitatively calculate the walking energy after a factor of walking energy was derived to predict the pedestrian volume in vertical and horizontal spaces. Second, the method of calculating the walking energy can be applied to the weights of the ERAM model, which provided the theoretical basis for future studies to predict the pedestrian volume of vertical and horizontal spaces in a building.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.1-18
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• 2008

Because we can usually get many information through analyzing trajectories of moving objects on spatial networks, efficient trajectory index structures are required to achieve good retrieval performance on their trajectories. However, there has been little research on trajectory index structures for spatial networks such as FNR-tree and MON-tree. Also, because FNR-tree and MON-tree store the segment unit of moving objects, they can't support the trajectory of whole moving objects. In this paper, we propose an efficient trajectory index structures based on signatures on a spatial network, named SigMO-Tree. For this, we divide moving object data into spatial and temporal attributes, and design an index structure which supports not only range query but trajectory query by preserving the whole trajectory of moving objects. In addition, we divide user queries into trajectory query based on spatio-temporal area and similar-tralectory query, and propose query processing algorithms to support them. The algorithm uses a signature file in order to retrieve candidate trajectories efficiently Finally, we show from our performance analysis that our trajectory index structure outperforms the existing index structures like FNR-Tree and MON-Tree.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.739-745
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• 2018

Recently, the incidence of heavy rainfall is increasing. Therefore, a rainfall analysis should be performed considering increasing frequency. The current rainfall analysis for hydrologic design use the hourly rainfall data of ASOS with a density of 36 km on the Korean Peninsula. Therefore, medium and small scale watershed included Thiessen network at the same rainfall point are analyzed with the same design rainfall and time distribution. This causes problem that the watershed characteristics can not be considered. In addition, there is a problem that the temporal-spatial change of the heavy rainfall occurring in the range of 10~20 km can not be considered. In this study, Author estimated design rainfall considering heavy rainfall using minutely rainfall data of AWS, which are relatively dense than ASOS. Also, author analyzed the time distribution and runoff of each case to estimate the huff's method suitable for the watershed. The research result will contribute to the estimation of the design hydrologic data considering the heavy rainfall and watershed characteristics.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.2
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• pp.273-280
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• 2010

This study aims to research into a plan for the spatial design on the major facilities in new-town region in Mongolia by using the spatial analytical technique in GIS. In case of Mongolian region, the demand for new-town development is rapidly increasing around Ulaanbaatar, where is the capital. On the other hand, the adequately relevant ground or the spatial-design technique is failing to be applied. This study extracted the region available for developing new down by using spatial analytical technique in GIS, and researched into the spatial-design plan for housing complex, filtration plant, sewage disposal plant, power plant, general park, crematory. The housing complex in the targeted region could be known to be adequate to be positioned around watercourse and road. It could be known to be adequate for filtration plant, which is the source of drinking water, to be located in the upper-stream region of a river, which is secured good quality of water, and for sewage disposal plant to be located in the lower-stream region available for minimizing occurrence of contamination. It is judged to be required for a proposed site of power plant to be located in the upper-stream region, for the park unit, which is space of the living culture, to be repaired and expanded the existing facilities, and for traffic network to be expanded through predicting demand along with new-town development. It is judged to be probably needed to be reflected even the flexible aspect for changing design through surveying the feasibility and economic efficiency on the future spatial design.