• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.815-816
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• 2012

In order to a quick response to disasters preparation, it is necessary to collect an disaster information quickly. In this study, it is essential to look for several methods to collect the information about disaster in real time, and we also examine how the collected information can be utilized in any way.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.33-35
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• 2017

We have been working on data processing and calibration of AKARI/IRC images from pointed observations. As of September 2014, a data package for each pointing only contains raw data and quick-look data, so that users have to process them using the toolkit by themselves. We plan to change this situation and to provide science-ready data sets, which are easy-to-use for non-AKARI experts. For Phase 1&2, we have updated dark and flat calibrations, and also the toolkit itself to produce images more reliable and easier to use. A new data package includes fully calibrated images with WCS information. We released it for about 4000 pointings at the end of March 2015.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.36.3-37
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• 2018

By utilizing large-scale graph analytic tools in the modern Big Data platform, Apache Spark, we investigate the topological structures of five different multiverses produced by cosmological n-body simulations with various cosmological initial conditions: (1) one standard universe, (2) two different dark energy states, and (3) two different dark matter densities. For the Big Data calculations, we use a custom build of stand-alone Spark cluster at KIAS and Dataproc Compute Engine in Google Cloud Platform with the sample sizes ranging from 7 millions to 200 millions. Among many graph statistics, we find that three simple graph measurements, denoted by (1) $n_\k$, (2) $\tau_\Delta$, and (3) $n_{S\ge5}$, can efficiently discern different topology in discrete point distributions. We denote this set of three graph diagnostics by kT5+. These kT5+ statistics provide a quick look of various orders of n-points correlation functions in a computationally cheap way: (1) $n = 2$ by $n_k$, (2) $n = 3$ by $\tau_\Delta$, and (3) $n \ge 5$ by $n_{S\ge5}$.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.171-176
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• 2022

The communication signal for quick cut-off specification is defined as "design to support fast cut-off requirements of all applicable photovoltaic(PV) systems" in NEC 2014, NEC 2017 or the corresponding UL standard regardless of the system configuration. On the other hand, if you look at the domestic regulations related to new and renewable energy, the standards, regulations, and guidelines set by each institution are general, or only the parts necessary for the institution are being established and operated. There are many insufficient points to apply these things to photovoltaic facilities, and there are cases where excessive facilities are installed according to the design, inspection standards of supervisors and inspection agencies, and the skill level of inspectors. The internationally accepted IEC standards deal with various facility standards in detail. In each European country, there are separate facility regulations based on IEC. In particular, the performance and safety of devices are dealt with in detail, and in the case of 'NEC Article 690' applied in North America such as the United States, each item is described in detail. Therefore, in this paper, we will look at the details of the PV shutdown technology that is currently used and applied internationally.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.185-205
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• 2014

SAR ground moving target indicator (GMTI) has long been an important issue for SAR advanced applications. As spatial resolution of space-borne SAR system has been significantly improved recently, the GMTI becomes a very useful tool. Various GMTI techniques have been developed particularly using multi-channel SAR systems. It is, however, still problematic to detect ground moving targets within single channel SAR images while it is not practical to access high resolution multi-channel space-borne SAR systems. Once a ground moving target is detected, it is possible to retrieve twodimensional velocities of the target from single channel space-borne SAR with an accuracy of about 5 % if moving faster than 3 m/s. This paper presents a quick-and-dirty method for detecting ground moving targets from single channel SAR single-look complex (SLC) images by differentiation. Since the signal powers of derivatives present Doppler centroid and rate, it is very efficient and effective for detection of non-stationary targets. The derivatives correlate well with velocities retrieved by a precise method with a correlation coefficient $R^2$ of 0.62, which is well enough to detect the ground moving targets. While the approach is theoretically straightforward, it is necessary to remove the effects of residual Doppler rate before finalizing the ground moving target candidates. The confidence level of results largely depends on the efficiency and effectiveness of the residual Doppler rate removal method. Application results using TerraSAR-X and truck-mounted corner reflectors validated the efficiency of the method. While the derivatives of moving targets remain easily detectable, the signal energy of stationary corner reflectors was suppressed by about 18.5 dB. It results in an easy detection of ground targets moving faster than 8.8 km/h. The proposed method is applicable to any high resolution single channel SAR systems including KOMPSAT-5.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.1
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• pp.59-67
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• 2017

In recent years, cyber terror that break into major institution's information system and destroy and paralyzed important information occurs frequently. Some countries do dangerous acts such as train hackers and order hackers to hack important industrial confidential documents which are core of national competitiveness to reduce the competitiveness of the country and cause social confusion. In this thesis, it will study problems of cyber terror to help people to use Internet in web environment that safe from cyber terror and to avoid the risk from cyber terror such as malware and DDos. This thesis is organized as following. In second chapter, it will look thorough the research that are related to cyber terror. In third chapter, it will study attack types of cyber terror. In fourth chapter, to defend from cyber violence, it will suggest safe solution. In fifth chapter, it will end with conclusion. Finally, to prevent urgent incidents like North Korean Cyber-attack, every Internet user must indicate their recognition on Internet security and it is significant to make a quick response treatment to create the safe online environment.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.569-572
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• 2002

Terra MODIS is one of the few space-borne sensors currently capable of acquiring radiometric data over the range of view angles. Institute of Industrial Science, University of Tokyo, has been receiving Terra MODIS data at Tokyo since May 2001 and Asian Institute of Technology at Bangkok since May 2001. They can cover whole East Asia and is expected to monitor environmental changes regularly such as deforestation, forest fires, floods and typhoon. Over eight hundred scenes have been archived in the storage system and they occupy 2 TB of disk space so far. In this study, MODIS data processing system on WWW is developed including following functions: spectral subset (250m, 500m, 1000m channels), radiometric correction to radiance, spatial subset of geocoded data as a rectangular area with latitude-longitude grid system in HDF format, generation of a quick look file in JPEG format. Users will be notified just after all the process have finished via e-mail. Using this system enables us to process MODIS data on WWW with a few input parameters and download the processed data by FTP access. An easy to use interface is expected to promote the use of MODIS data. This system is available via the Internet on the following URL from September 1 2002, "http : //webmodis.iis.u-tokyo.ac.jp/".

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.986-988
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• 2001

This paper presents a digitally speed sensorless control system for induction motor with direct torque control (DTC). Some drawbacks of the classical DTC are the relatively large torque ripple in a low speed range and notable current pulsation during steady state. They are reflected speed response and increased acoustical noise. In this paper, the DTC quick response are preserved at transient state, while better qualify steady state performance is produced by space vector modulation (SVM). The system are closed loop stator flux and torque observer for wide speed range that inputs are currents and voltages sensing of motor terminal, model reference adaptive control (MRAC) with rotor flux linkages for the speed fuming signal at low speed range, two hysteresis controllers and optimal switching look-up table. Simulation results of the suggest system for the 2.2 [kW] general purposed induction motor are presented and discussed.

• Journal of the Korea Fashion and Costume Design Association
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• v.9 no.1
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• pp.89-101
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• 2007

Young casual brands today is beset with perplexing difficulties, as consumer tastes become more sophisticated. Consumers request the type of product they want and how they want it differenciated from existing product. This study research that young casual brands seek to react to consumer who wants special and different fashion items, have a look for definite concept and target. Also In modem digital environment, Young Casual brands needs a quick and comprehensive action against a change of scene. So This study propose resort wear design with the use of computer graphics to applicate on young casual brands as developing various and effective design method, target on girlish young casual with unique indiviuality of lovely sensitivity. The result of this research as follows. First, young casual brands will have to seek ways to differentiate as brand identity, value of product, satisfaction for consumer's culture and lifestyle. Second, As a result of the adaptation of ethnic fashion, 8 resort wears designed development of girlish young casual wear using computer graphics. Third, computer graphics could contribute to the rapid composition of diverse, new and differenciated design research on it.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.113-121
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• 2015

This study aims to examine the risk of electrical fire in places where electric heat wires are used. In general, the use of electric heating wires is becoming more common and prevalent in a bid to prevent increasing damage caused by freezing and bursting in residential water pipes, factory pipes and irrigation pipes in vinyl greenhouse and a variety of heat wire products are available in market with legal safety requirements imposed on them. However, the widespread use of anti-freezing burst heat wire products has caused increasing incidents of fire, which often fail to be incorporated into statistics due to quick onsite extinguishing and insignificant damage although damage is gradually on the rise. Against this backdrop, this study aims to look into the possibility of ignition caused by electric heat wires and the mechanism of how it turns into catching fire through overheat and short circuit tests for anti-freezing burst electrical heat wires (hereinafter called the 'heat wire') and expects to serve as the basis for further observations and analyses on the cause of fire and the process of ignition in a scientific manner.