• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.695-707
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• 2013

DHT(Distributed Hash Table) networks such as Kademlia are vulnerable to the ID mapping attack caused by the voluntary DHT mapping structure where the location of a node is solely determined by itself on the network topology. This causes security problems such as eclipse, DRDoS and botnet C&C on DHT networks. To prevent ID mapping attacks, we propose a non-voluntary DHT mapping scheme and perform analysis on NAT compatibility, attack resistance, and network dynamicity. Analysis results show that our approach may have an equivalent level of attack resistance comparing with other defense mechanisms and overcome their limitations including NAT compatibility and network dynamicity.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.95-99
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• 2017

The lifetime of a battery that supplies all the power required by a satellite in the eclipse is directly related to the lifetime of the satellite. Because the lifetime of the battery is influenced by the charging method of the battery, the power control unit that controls the charging of the battery should be designed in consideration of battery life. The battery charging is performed by controlling the charge current in the power control unit generated from the solar cell in the daytime. In order to prevent overcharge of the battery and for considering frequency of eclipse in each season, parameters related battery charging should be designed differently according to the season and to prevent over-current charging and over-voltage charging during charging, charge current is controlled by monitoring battery charge / discharge status, charge current amount, battery voltage, battery capacity, battery temperature and battery cell voltage. In satellite, tapering method is used to control charge current by reflecting each condition. In this paper, design battery charging algorithm of satellite power control unit using tapering charging method. convert the designed algorithm into a code that can be uploaded to satellites and verify the operation through testing in the established satellite environment.

• Bulletin of the Korean Space Science Society
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• 1992.10a
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• pp.21-21
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• 1992

The X-ray binary pulsar Her X-1 was observed with Ginga on 1988 August 28 during the orbital phase of 0.76 to 0.85 at the main-on phase of the 35 day cycle. During the observations the X-ray intensity varied by a factor of five or more on a time scale as short as 30 sec, due mostly to the soft X-ray absorption in the pre-eclipse phase. From the studies of pulse profiles and energy spectra, we revealed that there exists in the dipphase an unpulsed component which is "3% of the intensity at the non-absorbed high-level. We suggest that scattering of the source continuum by the optically thin hot corona is responsible for the unpoised component. In the spectral analysis, we find that the high-state non-absorbed spectra can be fitted by a power-law without absorption, and the spectra observed in the different abgorption states by two components of a power-law with the same photon index. An iron-K emission line is required in to the cases of fitting. The estimated equivalent width of the iron line varies from 0.18 to 0.51 key according to the change in the absorption column density along the line of sight. We suggest that the fluorescent iron line arises in a cool and relatively small region, like the Alfvensur face, and may be partially intercepted by the optically thick gas cloud passing across the line of sight.1 Korea Astronomy Observatorya The Institute of Space and Astronautical Science in Japan3 Korea Advanced Institute of Science and Technology

• Journal of Astronomy and Space Sciences
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• v.25 no.1
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• pp.1-18
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• 2008

We present a detailed period analysis for the F-type primary of ${\in}$ Aurigae by means of Fourier and wavelet algorithm. After collecting all available data which have been observed for around 160 years (1842 - 2006) from various international databases and published references we selected only data obtained during outside eclipse among them again. As a result of analysis using CLEANest and WWZ(weighted wavelet Z-transform) several frequencies including two clear periods ($67^d\;and\;123^d$) were found. In contrast to previous results that the periods vary irregularly it seems that the primary of ${\in}$ Aurigae is double mode or multiperiodic pulsator. The presence of the two periods and their ratio indicates that the high-mass interpretation of the variable could be valid. Also better understanding of the mechanisms driving the light variability of F-type supergiant stars requires continual series of photometric and radial velocity measurements in outside eclipse of this star.

• Journal of Astronomy and Space Sciences
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• v.30 no.2
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• pp.79-82
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• 2013

We present the Hilbert-Huang transform (HHT) analysis on the quasi-periodic modulation of SMC X-1. SMC X-1, consisting of a neutron star and a massive companion, exhibits superorbital modulation with a period varying between ~40 d and ~65 d. We applied the HHT on the light curve observed by the All-Sky Monitor onboard Rossi X-ray Timing Explorer (RXTE) to obtain the instantaneous frequency of the superorbital modulation of SMC X-1. The resultant Hilbert spectrum is consistent with the dynamic power spectrum while it shows more detailed information in both the time and frequency domains. According to the instantaneous frequency, we found a correlation between the superorbital period and the modulation amplitude. Combining the spectral observation made by the Proportional Counter Array onboard RXTE and the superorbital phase derived in the HHT, we performed a superorbital phase-resolved spectral analysis of SMC X-1. An analysis of the spectral parameters versus the orbital phase for different superorbital states revealed that the diversity of $n_H$ has an orbital dependence. Furthermore, we obtained the variation in the eclipse profiles by folding the All Sky Monitor light curve with orbital period for different superorbital states. A dip feature, similar to the pre-eclipse dip of Her X-1, can be observed only in the superorbital ascending and descending states, while the width is anti-correlated with the X-ray flux.

• The Journal of Korean Association of Computer Education
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• v.16 no.6
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• pp.33-43
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• 2013

Compiler and language implementation courses have long been recognized as an important subject in Computer Science curricula. It is because not only the knowledge for a compiler plays important roles in understanding programming languages and systems but compiler technologies can be used in many applications. However it requires much effort to teach effectively it due to limited resources and time restriction. We present a compiler teaching model using Edu-IDEC which is a development environment of educational compilers. Edu-IDEC is a tool on the robot platform. It uses the Eclipse plug-ins and has functions like compiler developing tools, a reference compiler, visualization tool of syntax tree, visualization tool of object language, NXT robot controllers, and its simulator. We also present the evaluation results for our model by applying it to an actual class.

• Journal of Korean Medical classics
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• v.31 no.2
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• pp.83-103
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• 2018

Objectives: The Qing Dynasty experienced a development in Yunqi even greater than in the Ming Dynasty. Popularization and universalization of Yunqi theory led to many books on the subject published, especially with weights on Warm Heat Disease and Pestilence, also giving birth to new Yunqi theories. A study into this development has a great significance in the study of the traditional medicine in Qing. Methods: The paper studies the Yunqi books published in the Qing dynasty to find out the unique characters of those books. To understand the direction which the Yunqi theory in the Qing period took, the paper also reviewed the positions of different groups, those who were favorable, those who compromised, and those who were unfavorable. Results: Four directions were taken by the study of Yunqi in the Qing period. First is the systemic study and composition of Neijing's chapter of Yunqi. This direction was taken by Liumaoxiu's NeiJingYunQiBingShi) and $N{\grave{e}}ijingyunqibiao$, Xuefuchen's Suwenyunqitushuo, Zhuenhua's Suwenyunqiqianshuo, an unknown person's Su wen yunqi chao, Weigeliu's Neijingqihuapian. The second direction is the study of Yunqi in relation with the Warm Heat Disease and Pestilence, which was taken by Mayin lin's Wuyunliuqiwenyifayuan, Lumaoxiu's Suwenyipianbìngshi, Litianchi's Shiyiwenbingqìyunzhengyan lun, and Wangxun's Cihangsanyuanfujifang. The third direction deals with a new Yunqi theory. The Fourthis the explanation of Yunqi in the form of Songs, which was taken by Wuqian's Yunqiyaojue, and Wengzao's Yunqiyaojue. Conclusions: Ludanchen published Yunqibian, and explained that Haizichouyinmaochen, which is the eclipse's south latitude, becomes Nanzheng, and Southern government, which is the eclipse's north latitude, becomes Northern government. Lumaoxiu revealed that the Liuqidasitian, founded by Wangpuzhuang, his great grandfather on the mother's side, is in alignment with the theory of Dashitian, used by Liushozhen, Lidongyuan, Zhudanxi, and Zhangjingyue. The representative figure in the favorable view of Yunqi in the Qing period is Wuyang, that of those who compromised is Fengzhaozhang, and that of opposition is Zhangzhuo.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.219-221
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• 2015

We present our recent observations of SDSS J102102.25+174439.9, a new eclipsing white dwarf - main sequence WDMS binary with an orbital period of 0.14 days. This system belongs to the post common-envelope binary group as shown by the spectrum from the Sloan Digital Sky Survey. We obtained our data using the ULTRASPEC instrument installed on the 2.4-m telescope at the Thai National Observatory (TNO). Our multi-band observations reveal an unusual and persistent drop in brightness after the primary eclipse. These dips, which appear to show variations in amplitude, also have a complex shape that changes within days. Dips in WDMS systems have been observed on only one other occasion, in the light curve of QS Vir prior to the eclipse of the white dwarf. The dips in SDSS J1021+1744 are unique because they are present at different wavelengths and they occur approximately at similar phases. Hosting a DA white dwarf and an M4 companion star, this system is known to be the only WDMS to show these kind of dips in its light curve. It is possible that these dips are caused by ejected materials from an active companion star, such as in QS Vir. The light curve in the g' filter exhibits deep and narrow features, implying that the material which passes in front of the white dwarf in SDSS J1021 must be dense and small in size. Furthermore, we try to constrain the stellar and orbital parameters of SDSS J1021+1744 using the Binary Maker 3 software. We use g' and r' data for our light curve analysis to have a better approximation for the red dwarf star.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.143-151
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• 2010

According to increasing requirements in embedded systems. embedded software has been more complicated then before. a optimum software is difficult in embedded system. software developer make a difficult optimum software. this paper suggests a software profiling tool with which a software developer can easily profiling the embedded system software in cross-development environments. the suggested tool is designed based on host/target architecture. this tool insert program source for make profiling log to target program. a target program executed in target system. a target system communicate profiling log to host system. this tool in host system analyze profiling log data. and make a XML of profiling log and a profiling report. a profiling report is graphic viewer based GUI. a target system in this tool needs a few computing power. and XSLT can conversion of profile log XML to other format data. and suggested tool based on eclipse plug-in, therefore developer can use operates in eclipse.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.317-325
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• 2017

There has been a growing interest in programming education recently. However, to use most programming languages the corresponding compiler and IDE have to be installed on computers. To tackle this issue, though there developed several web-based programming environment including Eclipse Che and JDOODLE, most of them does not support GUI nor Korean programming languages. This paper proposes a web-based programming environment called Bombart, which supports Saesark, a Korean programming language, with GUI output. It also supports a console-based input and output. To support both kinds of interfaces, two compiling subsystems are designed and implemented. To test the effectiveness of the GUI support of Bombart, all the Java tutorial codes on GUI are translated into Saesark and executed on top of Bombart. According to this test, 81.42% of codes can be successfully converted and executed.