• Progress in Superconductivity and Cryogenics
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• v.17 no.4
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• pp.34-37
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• 2015

Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8-13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.97-97
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• 2003

Contrast-enhanced MR angiography (CE-MRA) gradually occupies its position as a primary evaluation tool forsteno-occlusive disease of supra-aortic cervical arteries. It has several advantages over time-of-flight (TOF) technique such as shorter imaging time, less saturation effect, and less flow- and motion-related artifacts. Diverse methods of k-space sampling, imaging sequences, and strategies for image acquisitiontiming have been introduced since its early clinical application. Especially, methods of k-space sampling and image acquisition timing are very important to achieve maximal arterial enhancement and suppress venous signal while maintaining large scan coverage and high spatial resolution. In addition, regardless of several advantages over TOF technique, it still has a tendency to overestimate the degree of stenosis in patients with carotid or vertebralartery disease. In this exhibit, we will overview the current techniques of CE-MRA with special attention to methods of k-space sampling and image acquisition timing. We will also discuss diagnostic accuracy of CE-MRA in patients with supra-aortic cervical artery stenosis and artifacts frequently misinterpreted as steno-occlusive lesion on CE-MRA.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.1
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• pp.3-12
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• 2012

It is a global trend to give attention to generating precise 3D navigation maps since eco-friendly vehicles have become a critical issue due to environmental protection and depletion of fossil fuels. To date, Mobile Mapping System (MMS) has been a efficient method to acquire the data for generating the 3D navigation maps. To achieve this goal so far in the Mobile Mapping System using the data acquisition method has been proposed to be most effective. For this study the basic RTF filter algorithm was applied to modify to fit MMS quantitative analysis derived floor 99.71%, 99.95% of the highly non-producers to maintain accuracy and high-precision 3D road could create DEM. In addition, the roads that exist within the cars, roadside tree, road cars, such as the median strips have been removed to shields it takes to get results effectively, and effective in practical applications and can be expected to improve operational efficiency is considered.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.75-90
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• 1998

In this study, as a method for management of waterquality in stream, we build a database on a environmental information such as a pollution source, a waterquality. And especially, we simulate the BOD concentration which is a index indicate the status of organic pollution in stream. Also This study purposes not only building a database on all sorts of envirnomental data, but also searching, statistic and analysis of the database. The result of this study enables us to see and understand contamination state in stream esaily, so it can help to enhance the attention. Also, we can quickly know study area and the degree of effects when water contamination occurs abruptly. And also, we can compare and know pollution source state and the pollutant load among districts. It is expected to use it as an auxiliary basis when we make a policy about pollutant load reduction, because we can know the extent of the pollution in strean by each a pollution source.

• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.1
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• pp.3-7
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• 1998

The issue of data accuracy brings a different perspective to the issue of GIS modeling, calls into a question the usefulness of data models such as DEM. Accuracy can be determined by randomly checking positional and attribute accuracy within a GIS data layer. With the increasing availability of DEM and the software capable of processing them, it is worthwhile to call attention for data accuracy and error analysis as GIS application depends on the priori established spatial data. The purpose of this paper was to investigate methods for data accuracy measurement and error detection methodology with two types of DEM's: 1 to 24,000 and 1 to 250,000 DEM released by U.S. Geological Survey. Another emphasis was given to the development of methodology for processing DEM's to create Arc/Info and GRASS layers. Data accuracy analysis with DEM was applied to a 250 sq.km area and an error was detected at a scale of 1:24,000 DEM. There were two possible reasons for this error: gross errors and blunders.

• Journal of Biomedical Engineering Research
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• v.39 no.1
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• pp.43-47
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• 2018

Traditional electroencephalography (EEG)-based authentication systems generally use external stimuli that require user attention and relatively long time for authentication. The aim of this study is to investigate the feasibility of biometric authentication based on EEG without using any external stimuli. Seventeen subjects took part in the experiment and their EEGs were measured while repetitively closing and opening their eyes. For identifying each subject, we calculated inter- and intra-subject cross-correlation using changes in alpha activity (8-13 Hz) during eyes closed as compared to eyes open. In order to optimize the number of recording electrodes, we calculated authentication accuracy by progressively reducing the number of electrodes used in the analysis. Significant increase in alpha activity was observed for all subjects during eyes closed, focusing on occipital areas, and spatial patterns of changed alpha activity were considerably different between the subjects. A mean authentication accuracy of 92.45% was obtained, which was retained over 75% when using only 8 electrodes placed around occipital areas. Our results could demonstrate the feasibility of the proposed novel authentication method based on resting state EEGs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.631-640
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• 2020

Currently, aircraft simulator has drawn a great attention because it has significant advantages of economic, temporal, and spatial costs compared with pilot training with real aircraft. Among the components of the aircraft simulator, flight dynamic model plays a key role in simulating the flight of an actual aircraft. Hence, it is important to verify the fidelity of flight dynamic model with an automated tool. In this paper, we develop a software to automatically verify the fidelity of the flight mechanics model for the efficient development of the aircraft simulator. After designing the software structure and GUI based on the requirements derived from the fidelity verification process, the software is implemented with C # language in Window-based environment. Experimental results on CTSW models show that the developed software is effective in terms of function, performance and user convenience.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.67-75
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• 2012

For the last few years, LBS has attracted considerable attention from many industries and societies as a result of propagated smart devices. LBS has a high utilization of mobile users as it uses user positions as a significant factor. Current LBS has only taken user position into account and it makes some limits. So, it is necessarily suggested that support for personalized services which consider user's motion, traffic condition, weather condition, time, personal information and preferences that have a huge impact on the accuracy. The purpose of this study is to design the inference systems with user's motion, preferences and schedules and provide users with the personalized information. To achieve this, Movement Ontology, User Profile Ontology, Schedule Ontology and Work Ontology should be constructed and based on this, smart applications were developed. Developed applications induced appropriately recommended results according to user's preference, motion and directions.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.1
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• pp.79-86
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• 2011

Recently, aerial laser scanning technology has received full attention in constructing DEM(Digital Elevation Model). It is well known that the quality of DEM is mostly influenced by the accuracy of DTD(Digital Terrain Data) extracted from LiDAR(Light Detection And Ranging) raw data. However, there are always misclassified data in the DTD generated by automatic filtering process due to the limitation of automatic filtering algorithm and intrinsic property of LiDAR raw data. In order to eliminate the misclassified data, a manual filtering process is performed right after automatic filtering process. In this study, an algorithm that detects automatically possible misclassified data included in the DTD from automatic filtering process is proposed, which will reduce the load of manual filtering process. The algorithm runs on 2D grid data structure and makes use of several parameters such as 'Slope Angle', 'Slope DeltaH' and 'NNMaxDH(Nearest Neighbor Max Delta Height)'. The experimental results show that the proposed algorithm quite well detected the misclassified data regardless of the terrain type and LiDAR point density.

• Asian review of World Histories
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• v.1 no.1
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• pp.5-44
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• 2013

This essay offers a historically based critique of the idea of "alternative modernities" that has acquired popularity in scholarly discussions over the last two decades. While significant in challenging Euro/American-centered conceptualizations of modernity, the idea of "alternative modernities" (or its twin, "multiple modernities") is open to criticism in the sense in which it has acquired currency in academic and political circles. The historical experience of Asian societies suggests that the search for "alternatives" long has been a feature of responses to the challenges of Euromodernity. But whereas "alternative" was conceived earlier in systemic terms, in its most recent version since the 1980s cultural difference has become its most important marker. Adding the adjective "alternative" to modernity has important counter-hegemonic cultural implications, calling for a new understanding of modernity. It also obscures in its fetishization of difference the entrapment of most of the "alternatives" claimed--products of the reconfigurations of global power--within the hegemonic spatial, temporal and developmentalist limits of the modernity they aspire to transcend. Culturally conceived notions of alternatives ignore the common structural context of a globalized capitalism which generates but also sets limits to difference. The seeming obsession with cultural difference, a defining feature of contemporary global modernity, distracts attention from urgent structural questions of social inequality and political injustice that have been globalized with the globalization of the regime of neoliberal capitalism. Interestingly, "the cultural turn" in the problematic of modernity since the 1980s has accompanied this turn in the global political economy during the same period. To be convincing in their claims to "alterity", arguments for "alternative modernities" need to re-articulate issues of cultural difference to their structural context of global capitalism. The goal of the discussion is to work out the implications of these political issues for "revisioning" the history and historiography of modernity.