• KIEE International Transactions on Power Engineering
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• v.5A no.2
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• pp.138-143
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• 2005

During faults, the voltage and current signals available to the relay are affected by the decaying dc component and harmonics. In order to make appropriate and accurate decisions, most of the relaying algorithms require the fundamental frequency phasor information that is immune to decaying dc effect and harmonics. The conventional Fourier ph as or estimation algorithm is affected by the presence of decaying-exponential transients in the fault signal. This paper presents a modified Fourier algorithm, which effectively eliminates the decaying dc component and the harmonics present in the fault signal. The decaying dc parameters are estimated by means of an out-of-band filtering technique. The decaying dc offset and harmonics are removed by means of a simple computational procedure that involves the design of two sets of Orthogonal digital OFT filters tuned at different frequencies and by creating three off-line look-up tables. The technique was tested for different decay rates of the decaying dc component. It was also compared with the conventional mimic plus the full cycle OFT algorithm. The results indicate that the proposed technique has a faster convergence to the desired value compared to the conventional mimic plus OFT algorithms over a wide range of decay rates. In all cases, the convergence to the desired value was achieved within one cycle of the power system frequency.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.292-294
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• 2001

멀티캐스트 정보보호 기술은 순수만 멀티캐스트 기술을 실용화 하는데 있어서 없어서는 안될 기술이다. 멀티캐스트 정보보호 기술에서 이슈가 되는 것은 여러 가지가 있으나, 본 논문에서는 인증된 수신자만이 데이터를 볼 수 있도록 하기 위해 필요한 키의 분배 및 rekey 연산에 대해 제안된 몇 가지 기술을 알아보고. 무선환경에서도 확장성을 제공할 수 있는 방안으로 기존의 OFT(One-way Function Tree) 메커니즘을 토대로 하는 WOFT(Mobile OFT) 메커니즘을 제안하고 제안하는 MOFT 메커니즘의 효율성을 분석한다.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.75-76
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• 2006

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.391-394
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• 2001

본 논문에서는 OFT(One-way Function Trees)를 사용한 안전한 멀티캐스트 프로토콜을 제안한다. 그룹 키의 생성시 모든 멤버의 참여를 보장하며, 각 멤버는 독립적으로 그룹키를 계산한다. 제안하는 프로토콜은 그룹키의 생성시 해쉬 함수와 비트단위 XOR 연산만을 수행하기 때문에 속도가 빠르며, 멤버의 가입, 탈퇴가 빈번히 발생하는 동적인 환경에서도 적합하다.

• Structural Engineering and Mechanics
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• v.34 no.4
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• pp.541-544
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• 2010

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.9
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• pp.261-280
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• 2004

DaF-Lehrende in Korea erfahren oft, dass koreanische DaF-Lernende $\"{u}ber$ ein gutes Regelwissen im Deutschen $verf\"{u}gen$, aber oft nur weinh verstehen und sprechen $k\"{o}nnen$. Das bedeutet, dass das Auswendiglernen von grammatischen Regeln und ihr tatsachliches Anwenden zweierlei sind. Wenn Grammatikkompetenz mit der fremdsprachlichen Kompetenz nicht gieichzusetzen ist, stellt sich die Frage, wie den Lemern durch die Grammatik ein $selbst\"{a}ndiges$ Erlernen von erammatischen Eigenschaften bis hin zur freien Anwendung des Gelernten in den Kommunikationssituationen $erm\"{o}glicht$ werden kann. $F\"{u}r$ die Antwort auf die Frage werden im vorliegenden Artikel Lornergrarnmatik und ihre didaktischen Prinzipien vorgestelit. In der Lornergrarnmatik handelt es sich um die Beschreibung des Regelsystems einer Sprache $f\"{u}r$ Unterrichtszwecke. Das ist mehr als eine Sprachbeschreibung. Sie $ber\"{u}cksichtigt$ dabei den Sanzen Lern- und Lehrverlauf von Regeln und auch die didaktiche Frage, wie man ein Reselsystem aufteilen, darstellen und im Unterricht $pr\"{a}sentieren$ kann

• Herbal Formula Science
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• v.30 no.3
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• pp.109-121
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• 2022

Objective : This study is conducted to investigate the effect of Astragali Radix on Post Traumatic Stress Disorder(PTSD) induced by the Single Proposed Stress(SPS). Methods : The experiment was conducted with five groups; SAL groups with only saline treatment, SPS group, SPS + ARX25 group, SPS + ARX50 group, and SPS + ARX100 group. After applying SPS, saline and ARX were administered for 14 days to identify the change of body weight, sucrose intake amount, and behavioral changes through Open Field Test(OFT) and Forced Swimming Test(FST). After the behavioral experiment, plasma corticosterone levels, serotonin, norepinephrine and dopamine concentrations were measured by enzyme-linked immunoassay in medical prefrontal cortex, hippocampus, and amygdala. Brain-derived neurotrophic factor(BDNF) in the hippocampus was measured using Reverse Transcription Polymerase Chain Reaction. Results : Weight change has significantly decreased in the SPS group compared to the SAL group(p<0.05). On day 14, the sucrose intake of rats has significantly increased in the SPS + ARX100 group compared to the SPS group(p<0.05). In OFT, the number of staying in the central space has significantly increased in the SPS + ARX100 group(p<0.01). In FST, immobility has significantly decreased in SPS + ARX50 group and SPS + ARX100 group(p<0.05). The concentration of serotonine, dopamine and BDNF expression has increased significantly in SPS + ARX100 group compared to SPS group(p<0.05) Conclusions : In the SPS-induced PTSD experiment, ARX increased sucrose intake and the numbers of crossing in the central zone space in OFT, decreased immobility time in FST, and increased concentration of serotonin, dopamine, and BDNF. It can be postulated that the ARX could be effective for the treatment of PTSD.

• Journal of Life Science
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• v.26 no.2
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• pp.181-189
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• 2016

The aim of this study was to identify the effects of dithiopyr (DTP), a herbicide, on behavior in zebrafish. The toxicity of DTP has rarely been investigated in fish. In the present study, zebrafish were exposed to different concentrations of DTP in the range of 10-20 μM for 48 h in a test container, in order to measure the value of median lethal concentrations (LC₅₀). Behavioral experiments were performed, including the novel tank test (NTT) and the open field test (OFT), to assess stress responses or locomotion. After exposure to the DTP solution at a sublethal concentration of 2.5–10 μM for 6 min, the behavior of the zebrafish was observed for 6 min. In the acute toxicity test, the LC₅₀ value of DTP showed as 14.49 μM in the zebrafish. The NTT showed that the duration of immobility and the velocity were significantly increased by exposure at a concentration of 5 μM of DTP, compared with a control group (p<0.05). However, compared with the control group, DTP significantly decreased the distance moved and the frequency at the top of the tank, and significantly increased the turn angle and duration at the bottom, in a concentration-dependent manner (p<0.05). In addition, in the OFT, exposure to DTP significantly decreased the distance moved and velocity compared with the control group (p<0.05). Exposure to DTP also significantly increased the duration of immobility, the turn angle, and the meandering movement, in a concentration-dependent manner (p<0.05). Further, exposure to DTP at a low concentration elevated whole-body cortisol levels in the zebrafish. The results of this study thus suggest that DTP induces a toxic response and negative effects on behavior and the endocrine system in zebrafish.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.152-156
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• 2001

In this paper we propose a secure multicast key distribution protocol using OFT(One-way Function Trees). The proposed protocol is a hybrid scheme of DKMP(Distributed Key Management Protocol) that guarantees all group member's participation for generating a group key, and CKMP(Centralized Key Management Protocol) that makes it easy to manage group key and design a protocol. Since the proposed protocol also computes group key using only hash function and bitwise-XOR, computational overhead ran be reduced. Hence it is suitably and efficiently adaptive to dynamic multicast environment that membership change event frequently occurs.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.5
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• pp.91-108
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• 2002

In der vorliegenden Arbeit werden einige Aspekte der Interaktion zwischen Valenz und Informationsstruktur am Beispiel der deutschen lokalen Verben behandelt. Lokale Verben stellen ein Problem $f\"{u}r$ die Beschreibung der Valenz (bzw. Argumentstruktur) dar, da ihre $\"Adverbialerg{a}nzungen$ sowohl obligatorisch als auch fakultativ sein $k\"{o}nnen$ und es noch kein handhabbares syntaktisches Kriterium gibt, das fakultative $\"Adverbialerg{a}nzungen$ von freien Angaben klar trennen $k\"{o}nnte$. Die hier sehr stark voneinander abweichenden $Einsch\"{a}tzungen\;f\"{u}hren$ oft zur Entwicklung von immer differenzierteren Valenzmodellen. Dazu $z\"{a}hlt$ ein Mehrebenenmodell, das sich an die sogenannte 'Zwei-Stufen-Semantik' von Bierwisch und Lang orientiert. In diesem Rahmen sind in der letzten Zeit einige Arbeiten entstanden, die sich mit der obengenannten Problematik $besch\"{a}ftigen$. Hier wird die $Fakultativit\"{a}t\;der\;lokalen\;Erg\"{a}nzung$ von Bewegungs- und Positionsverben auf Prinzipien des semantischen und konzeptuellen Systems $zur\"{u}ckgef\"{u}hrt$. Die in diesem Zusammenhang oft angenommenen kognitiven Mechanismen wie 'konzeptuelle Verschiebung', 'Fokussierung' des $Moduspr\"{a}dikats$, 'Defokussierung' der Lokalisierungsrelation, 'Altematenbildung', 'Kontrastiertheit' u. a. sind aber mit den informationstrukturellen Begriffen und Mechanismen kompatibel, und das $Ph\"{a}nomen\;der\;Fakultativit\"{a}t\;der\;Adverbialerg\"{a}nzung$ bzw. der Notwendigkeit der Angabe ist auch unter Perspektive des Zusarnmenspiels von Grarnmatik und Informationsstruktur (Topik-Kommentar­Struktur und Hintergrund-Fokus-Struktur) $erkl\"{a}rbar$.