• International conference on construction engineering and project management
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• 2022.06a
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• pp.1255-1255
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• 2022

Recently, research on digital twins to generate digital information and manage construction in real-time using advanced technology is being conducted actively. However, in the construction industry, it is difficult to optimize and apply digital technology in real-time due to the nature of the construction industry in which information is constantly fluctuating. In addition, inaccurate information on the topography of construction projects is a major challenge for earthmoving processes. In order to ultimately improve the cost-effectiveness of construction projects, both construction quality and productivity should be addressed through efficient construction information management in large-scale earthworks projects. Therefore, in this study, a 3D digital map-based AR site management work support system for higher efficiency and accuracy of site management was proposed by using unmanned aerial vehicles (UAV) in wide earthworks construction sites to generate point cloud data, building a 3D digital map through acquisition and analysis of on-site sensor-based information, and performing the visualization with AR at the site By utilizing the 3D digital map-based AR site management work support system proposed in this study, information is able to be provided quickly to field managers to enable an intuitive understanding of field conditions and immediate work processing, thereby reducing field management sluggishness and limitations of traditional information exchange systems. It is expected to contribute to the improvement of productivity by overcoming factors that decrease productivity in the construction industry and the improvement of work efficiency at construction sites.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.343-353
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• 2017

Objective: This study aims to evaluate the efficiency of two representative subway map design types, namely a diagram type and a geographical type using physiological metrics, performance metrics, and self-reported metrics, which are representative usability metrics. Background: Subway maps need to be designed in order for users to quickly search and recognize subway line information. Although most cities' subway maps currently use the diagram type designed by Henry Beck, New York City's subway map has recently been changed to the subway map type combined with the geographical type designed by Michael Hertz. However, not many studies on its efficiency are found, and the studies that are available mainly depend on questionnaire surveys or take on a subjective behavioral study type based on experts' experiences. In this regard, evaluation through a more objective method is needed. Method: This study employed usability metrics as a method to evaluate the efficiency of information search targeting the diagram type and geographical type subway maps used mostly as subway maps. To this end, physiological metrics obtained through eye tracking, task completion time, representative metric of task performance, and subjective evaluation metrics were used for the suitability evaluation of subway map designs. Results: In the result of gaze movement distance analysis, no significant difference was shown in the two design types in terms of a process finding a departure station from the starting point and a process finding a transfer station between the departure station and arrival station (destination). However, the gaze movement distance in the process finding the arrival station at the departure station was significantly shorter in the geographical type, rather than in the diagram type. The analysis of task completion time showed a result similar to the gaze movement distance analysis result. Task completion time was significantly shorter in the geographical type, rather than in the diagram type, which is in the process finding the arrival station at the departure station. In other information search processes, no significant difference was shown. As a result of subjective evaluation metrics analysis, no significant difference was revealed in the two design types. Conclusion: An analysis on the two representative subway map design types was carried out via the adoption of usability metrics. As a result, although no significant difference was shown in some information search processes, it was revealed that information search was easier in the geographical type overall. Also, it was found that usability metrics can be effectively used to evaluate the design types of subway maps. Application: The study results can be used to set design direction to offer ease in information search on subway lines. The study also can be used as a method to evaluate a subway map's design type.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1865-1872
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• 2009

This study suggests a method for extending XMDR to integrate and search legacy system. This extension blends MSO(Meta Semantic Ontology) for the management of metadata, ML(Meta Location) for the management of location information, and Topic Map which is the standard language used to represent semantic web. This study refers to it as TMDR(Topic Map MetaData Registry). As an intelligent layer, Topic Map functions like an index. However, if the data frequently changes, the efficiency of Topic Map may drop. To solve this problem, the proposed system represents the relation among metadata, the relation among real data, and the relation between metadata and real data as Topic Map. The represented Topic Map proposes a method to reduce the changing relation among real data caused by the relation among metadata.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.13-19
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• 2018

MapReduce, the Hadoop's essential core technology, is most commonly used to process big data based on the Hadoop distributed file system. However, the existing MapReduce-based big data processing techniques have a feature of dividing and storing files in blocks predefined in the Hadoop distributed file system, thus wasting huge infrastructure resources. Therefore, in this paper, we propose an efficient MapReduce-based big data processing scheme. The proposed method enhances the storage efficiency of a big data infrastructure environment by converting and compressing the data to be processed into a data format in advance suitable for processing by MapReduce. In addition, the proposed method solves the problem of the data processing time delay arising from when implementing with focus on the storage efficiency.

• The Journal of Korea Robotics Society
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• v.8 no.4
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• pp.256-265
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• 2013

A local map-based exploration algorithm for mobile robots is presented. Segmented frontiers and their relative transformations constitute a tree structure. By the proposed efficient frontier segmentation and a local map management method, a robot can reduce the unknown area and update the local grid map which is assigned to each frontier node. Although this local map-based exploration method uses only local maps and their adjacent node information, mapping completion and efficiency can be greatly improved by merging and updating the frontier nodes. Also, we suggest appropriate graph search exploration methods for corridor and hall environments. The simulation demonstrates that the entire environment can be represented by well-distributed frontier nodes.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.6
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• pp.604-611
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• 2012

For the commercialization of fuel cell powered vehicle, it is highly important to improve the performance and efficiency of an automotive polymer electrolyte membrane fuel cell (PEMFC) system. The performance and efficiency of PEMFC systems are significantly influenced by their operating conditions. Among these conditions, the system operating pressure is considered as the one of the main factors. In this study, to investigate the effects of operating pressure on the performance and efficiency of automotive PEMFC systems, two types of high-pressure operating PEMFC systems adopting two different compressors (i. e. different performance maps) are modeled by using MATLAB/Simulink environment. The PEMFC system efficiency and parasitic compressor power are mainly analyzed and compared for the two types of high-pressure operating PEMFC systems under the same system net power conditions. It is expected that this kind of study can contribute to provide basic insight into the operating strategies of high-pressure operating PEMFC systems for automotive use.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.337-342
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• 2023

Since the electric vehicle uses an electric motor, problems have arisen as the driver hears the inherent noise of the motor or external noise, which was not a problem in the past, due to the overall lower noise environment than when using an internal combustion engine. Therefore, the purpose of this paper is to reduce the noise and vibration of electric motors for electric vehicles, and recently, to increase the speed of high-power, high-efficiency electric motors in a small size, and to develop low-noise motors, IPM motors are applied to produce 35KW electric motors for electric vehicles. A motor for low noise was designed and implemented. N-T Curve and efficiency map were confirmed as the final result of developing a 35KW low-noise motor for electric vehicles by applying the IPM motor applied in this paper. Based on 3500 rpm, Max Torque [Nm]: 121.15, Max Power [KW]: 44.04, and Max Efficiency [%]: 97.65, showing high efficiency.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.87-90
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• 2007

Many moderncommunication technologies are developing based on internet protocol (IP) and there is many work to archive seamless mobility service. IETF proposed MIPv6 protocol that uses IPv6 to provide mobility services to mobile node however it has some limits like sending and receiving too many messages during binding update (BU) procedure. So, now a day it makes HMIPv6(Hierarchical Mobile IPv6). HMIPv6 solves overhead and transmission delay problem in MAP(Mobile Anchor Pointer), but it can't accomplish effectively Macro handover between MAPs. This paper introduces use of FMIPv6 and Selective handover mechanisms based on hierarchical MAP information in HMIPv6 for improvement of handover efficiency.

• Journal of Korea Multimedia Society
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• v.18 no.2
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• pp.149-157
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• 2015

The 3D-AVC standard aims at improving coding efficiency by applying new techniques for utilizing intra, inter and view predictions. 3D video scenes are rendered with existing texture video and additional depth map. The depth map comes at the expense of increased computational complexity of the encoding process. For real-time applications, reducing the complexity of 3D-AVC is very important. In this paper, we present a fast intra mode decision algorithm to reduce the complexity burden in the 3D video system. The proposed algorithm uses similarity between texture video and depth map. The best intra prediction mode of the depth map is similar to that of the corresponding texture video. The early decision algorithm can be made on the intra prediction of depth map coding by using the coded intra mode of texture video. Adaptive threshold for early termination is also proposed. Experimental results show that the proposed algorithm saves the encoding time on average 29.7% without any significant loss in terms of the bit rate or PSNR value.

• Journal of Advanced Navigation Technology
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• v.13 no.6
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• pp.831-837
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• 2009

This paper suggests the method for saving the digital map which was made through aerial photography to ORDBMS (Object Relational Database Management System) and analyze its efficiency through experiments. The digital map has been used by file units because of managing or providing it to others. But this way can not get sequential graphic entities and just use it which was included in only one map. In this paper, we saved the digital map to ORDBMS at a time after converted the digital map entities based on the tile to the things can be inserted to ORDBMS. And, we also proved the possible methods to extract the graphic entities what we need from entire blueprint through experiments.