• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.293-305
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• 2020

An eruption of Taal Volcano in the Philippines began on January 12, 2020. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) subsequently issued an Alert Level 4, indicating that "a hazardous explosive eruption is possible within hours to days." It was a phreatic eruption and phreatomagmatic eruption from the main crater that spewed ashes to Calabarzon, Metro Manila, some parts of Central Luzon, and Pangasinan in Ilocos Region, resulting in the suspension of classes, work schedules, and flights. By January 26, 2020, PHIVOLCS observed inconsistent, but decreasing volcanic activity in Taal, prompting the agency to downgrade its warning to Alert Level 3. After February 14, Alert status was set to Level 2 because of overall decreasing trend of volcanic activities, but it does not mean that the threat of an eruption has disappeared. In addition, the Alert Level can be raised to Alert Level 3 if there is a symptom of increasing unrest at any time.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.9
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• pp.73-84
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• 2004

This paper suggests a new scalar multiplication algerian to resist SPA which threatens the security of cryptographic primitive on the hardware recently, and discusses how to apply this algerian Our algorithm is better than other SPA countermeasure algorithms aspect to computational efficiency. Since known SPA countermeasure algorithms have dependency of computation. these are difficult to construct parallel architecture efficiently. To solve this problem our algorithm removes dependency and computes a multiplication and a squaring during inversion with parallel architecture in order to minimize loss of performance. We implement hardware logic with VHDL(VHSIC Hardware Description Language) to verify performance. Synthesis tool is Synplify Pro 7.0 and target chip is Xillinx VirtexE XCV2000EFGl156. Total equivalent gate is 60,508 and maximum frequency is 30Mhz. Our scalar multiplier can be applied to digital signature, encryption and decryption, key exchange, etc. It is applied to a embedded-micom it protects SPA and provides efficient computation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.379-384
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• 1995

The retinomotor responses of jack mackerel, Trachurus japonicus and carp, Cyprinus carpio were studied for the different strobe flash frequencies in respects of the application of the light stimulus to herding and barrier system. The strobe flash frequencies ranged at 1.7, 5, 10, 25, 430Hz in jack mackerel and 1.7, 5, 25Hz in carp. The retinal adaptation ratio was examined histologically according to the time elasped of 1, 5, 10, 30min after turning on the light in each experimental condition. Cone index were determined in order to express the retinal adaptation ratio. Jack mackerel showed an increase of the retinal adaptation ratio ranging from average 27% at the pre-stimulus light to 42.6%, 49.8%, 59.8% and 83.1% at the irradiation times of 1, 5, 10 and 30min., respectively. Carp showed an increase of the retinal adaptation ratio ranging from average 28.4% at the pre-stimulus light to 51%, 53.9% and 91.3% at the irradiation times of 1, 5 and 30min., respectively. The light adaptation process was observed to be fast approximately in order of 430Hz, 25Hz, 5Hz, 1.7Hz and 10Hz for jack mackerel, and 25Hz, 5Hz and 1.7Hz for carp, and to be light-adaptated in 30 minutes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.118-125
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• 2007

The lightning surge and switching surge could be injected to the underground distribution line through the riser pole in the mixed distribution line of overhead and underground. These surges travel along the cable and are reflected at the end of cable. It can be doubled and affecting underground distribution facilities. It was made a underground distribution model representing KEPCO's distribution system. It was measured propagation characteristics by applying lightning surges to this underground distribution model. Meanwhile, this system was simulated with ATP-EMTP and compared these real test results md tuned up the EMTP parameters. EMTP simulation results showed that accord with real test result by adjusting the cable insulation permitivity, arrester characteristics, surge wave shape.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.594-600
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• 2014

In modern warfare, securing communication channel by combatting opponents' electromagnetic attack is a crucial factor to win the war. Military satellite digital transponder is a communication payload of the next generation military satellite that maintains warfare networks operational in the presence of interfering signals by securely relaying signals between ground terminals. The transponder in this paper is classified as a partial processing transponder which performs cost effective secure relaying in satellite communication links. The control functions of transmission security achieve immunity to hostile interferences which may cause malicious effects on the link. In this paper, we present an efficient architecture for implementing the control mechanism. Two major ideas of pipelined processing in per-group control and software processing of blocked band information dramatically reduce the complexity of the hardware. A control code sequence showing its randomness with uniform distribution is exemplified and qualification test results are briefly presented.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.53-60
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• 2017

In contemporary philosophy, the thinking subject became the dis-constructed subject and there was not left any one center in thinking. On the contrary of this trend, the philosopher Levinas stresses 'an ethics of Otherness' that requires the subject to be responsible for the Other. For Levinas, the Other is not knowable and cannot be made into an object of the self. For Levinas, the irreducible relation, the epiphany, of the face-to-face, the encounter with another, is a privileged phenomenon in which the other person's proximity and distance are both strongly felt. The face of the Other comes toward me with its infinite moral demands while emerging out of the trace. In the movie , when Sachie encounters them, she greets them. She provides them with food and shelter to protect from the dangers of elements. With the help of Sachia, the restaurant becomes a peaceful communal place for her and the Other.

• Journal of Internet Computing and Services
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• v.21 no.2
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• pp.73-80
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• 2020

Due to the expansion of cyber space, war patterns are also changing from traditional warfare to cyber warfare. Cyber warfare is the use of computer technology to disrupt the activities of nations and organizations, especially in the defense sector. However, the defense against effective cyber threat environment is inadequate. To complement this, a new cyber warfare operation concept is needed. In this paper, we study the concepts of cyber intelligence surveillance reconnaissance, active defense and response, combat damage assessment, and command control in order to carry out cyber operations effectively. In addition, this paper proposes the concept of cyber warfare operation that can achieve a continuous strategic advantage in cyber battlefield.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.5
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• pp.455-461
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• 2016

Survivability of an aircraft has been greatly threatened by the development of a weapon system using infrared. Therefore, the infrared stealth technology is a very important technique to improve the survivability of an aircraft. In this study, the infrared signal of an aircraft was analyzed which corresponding to the aircraft surface temperature and environmental conditions with various surface conditions(especially emissivity changed). Based on the analyzed infrared signal, the optimized surface emissivity was suggested to reduce the average contrast radiance and contrast radiant intensity(CRI). In addition, we confirmed that the infrared contrast radiant intensity between the aircraft and the background can be minimized through an appropriately controlled surface emissivity of the aircraft at specific background.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2008.11a
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• pp.37-51
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• 2008

인삼은 재배적지에 대한 선택성이 매우 강한 식물이며, 기후 토양 등의 자연환경이 적당하지 않으면 인삼의 생육이 곤란하고, 생육이 가능하더라도 생산된 인삼의 형태, 품질 및 약효에서 현저한 차이를 나타내고 있다. 이러한 인삼의 식물학적 특성이 우리나라에서는 최적의 환경조건으로 인정되어 고려인삼은 세계적으로 최고의 품질로 높이 평가되는 이유이다. 하지만 실질적인 인삼의 생리활성물질에 대한 연구는 서구열강 및 일본에 의해 대다수 연구, 발표되었으며 또한 인삼의 우수성을 인정하여 넓은 영토와 수많은 과학적 지식으로 고려인삼의 우수한 품질을 앞서가려 하고 있는 것이 현실정이다. 특히 중국의 넓은 인삼재배면적에서 값싸게 생산된 인삼이 한국시장을 위협하고 있으며, 미국과 캐나다에서 수많은 연구비를 투자하여 자국삼인 화기삼의 홍보를 대대적으로 함으로서 전세계의 인삼시장의 변화를 유도하고 있고, 호주, 뉴질랜드에서도 청정인삼을 내세워 한국 및 전세계 인삼시장을 잠식해가고 있다. 이런 변화에 의하여 한때 인삼의 종주국으로 전세계의 인삼시장을 석권했던 한국의 고려인삼이 과거의 위상을 점차 잃어 가고 있는 실정이다. 따라서 인삼재배면적이 경쟁국과 비교해 상대적으로 열세인 한국의 고려인삼이 선택할수 있는 방법은 비록 생산은 적더라도 고부가가치인삼을 생산하여 명품화로 가야 할 것으로 생각된다. 명품화를 위해서는 우선 고려인삼의 효능을 밝혀 고기능성을 입증해야하고, 재배생산단계에서부터 농약, 중금속등에 노출되지 않고 병에 자유로운 청정재배를 통해 명품화를 이룩해야 하며, 특히 제품의 생산 및 유통단계에서 표준화를 통해서 전세계의 소비자가 믿고 사용할수 있도록 해야 할 것이다. 또한 인삼에만 함유된 인삼사포닌(ginsenoside)은 배당체로서 여러 미생물에 의하여 당사슬이 끊어짐으로서 새로운 사포닌이 등장하게 되는데 이러한 사포닌이 각종 함암, 면적, 치매, 관절등에 탁월한 효능을 보임으서 많은 연구들이 진행중에 있으며, 특히 인삼에만 함유된 것으로 알고 있었던 ginsenoside가 돌외(한약재명 칠엽담)에도 함유되어 있고 일부 성분은 미생물을 통해서 변환시킴으로 서 값비싼 인삼사포닌을 생장이 빠르면 비교적 값싼 돌외 사포닌으로부터 생산할수 있게 되었다. 본 세미나에서는 각종 미생물을 이용하여 인삼의 사포닌을 변환시키고 돌외 사포닌인 gypenoside를 ginsenoside로 변환시켜 대량생산할 수 있는 방법을 제시하고자 한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.5
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• pp.831-847
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• 2013

The various types of data are being created in large quantities resulting from the spread of social media and the mobile popularization. Many companies want to obtain valuable business information through the analysis of these large data. As a result, it is a trend to integrate the big data technologies into the company work. Especially, Hadoop is regarded as the most representative big data technology due to its terabytes of storage capacity, inexpensive construction cost, and fast data processing speed. However, the authentication token system of Hadoop Distributed File System(HDFS) for the user authentication is currently vulnerable to the replay attack and the datanode hacking attack. This can cause that the company secrets or the personal information of customers on HDFS are exposed. In this paper, we analyze the possible security threats to HDFS when tokens or datanodes are exposed to the attackers. Finally, we propose the secure authentication protocol in HDFS based on hash chain.