• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.4
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• pp.467-473
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• 2017

In this paper, impact characteristics of a water entry gliding vehicle were analyzed using a finite element method. To guarantee the validity of analysis results, a convergence test was performed for several ratios of Euler and Largrange mesh sizes. The impact coefficient was calculated with respect to entry angles and angle of attacks. It can be observed that the impact coefficient was large at a high cross-section gradient and was also affected by cavitation. This study could be useful in the preliminary design stage of a water entry bomb development.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.57-63
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• 1976

The lecturer pointed the agriculture in change brought about population bomb and economic development, and he appealed the scientists of soil and fertilizer to make proposals for establishing their constructive attitudes toward the situations of agriculture. The points emphasised by the lecturer for the improvement of future food situation were: fox example the elucidation of the ancient agricultural technology of Korea which is a important attempt for development of agricultural technology of Korea and Japan, and soil improvement with special attention to the efficiencies of phosphate, silicate, cations and trace elements. He showed some Japanese examples of natural pollution as both of a sufferer and an assailant of agriculture which are resulted from the high economic development, and some methods of solution, for example active application of legumes capable for fixing atmospheric nitrogen to wasted soils. He also pointed the need of lower consumption of energy and resources, and new understanding of wild plant species for the future agriculture. Some methods of other fields of sciences were emphasised for developing the soil and fertilizer researches.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.101-108
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• 2019

In this study, the hole-cavity resonance technology and the micro pore stainless chip sintering technology were fused to develop silencers with excellent noise attenuation performance even at fluid pressures exceeding 30 bar for the first time at home and abroad. As a result of this study, the noise attenuation performance was greatly improved as reflection, loss, and resonance were made to occur thousands of times simultaneously when fluids pass through the sintered micro pore stainless steel chip sound absorber. The noise of the gas emitted from the bomb without the silencer was shown to be 125dB. And noise test conducted after installation of the silencer showed the noise of 67dB. Given the study results, the amount of noise was greatly reduced in the sintered silencer.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.6
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• pp.602-609
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• 2021

Aircraft radar has special function which is ranging from aircraft to ground of antenna boresight. Because ranging information is used to calibrate altitude of aircraft or to drop a conventional bomb, the measuring have to be precise and robust. Therefore, we propose a simple and efficient method using monopulse radar for ground ranging. Proposed method calculates balancing weight according to linearity of monopulse ratio and mixes two ranging measurements in proportional to the weight. By exploiting balancing weight, radar is able to react to various environment as monopulse ratio contains characteristics of clutter environment. As a result, robust ranging information can be achieved. We use DEM(Digital Elevation Model) in order to simulate heterogeneous environment. In experimental result, it is shown that proposed method shows better accuracy and precision in any environment.

• Advances in concrete construction
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• v.15 no.4
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• pp.229-239
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• 2023

Anti-tank weapons are among the infantry weapons used by the armies of many countries. Anti-tank rockets and explosives such as TNT, generally used for armour piercing, are also frequently used in terrorist attacks. These attacks damage the protection facilities built from reinforced concrete. Rockets or similar explosives' rapid speed and burst temperatures pierce reinforced concrete during strikes, resulting in casualties and damage to crucial strategic structures. This study aimed to devise an economic and applicable reinforced concrete plate that could absorb the impact of anti-tank rockets and Trinitrotoluene (TNT) type explosives. Therefore, 5 different samples, produced from C50 reinforced concrete and 150×150 cm in size, were formed by combining plates of different numbers and thicknesses. Also, a sample, which was a single thick plate, was prepared. In destructive testing, Rocket Propelled Grenade (RPG-7) was used as the anti-tank rocket launcher. As a result of this study, the impact damage was reduced with hollow concrete plate geometries, and recommendations were developed for complete prevention.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.7-15
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• 2004

This research was designed to investigate the antioxidant activity of red cabbage (Brassica oleracea L., BO) fractions on the liposomes consisted of L-$\alpha$-dilinoleoylphosphatidylcholine (DLPC-liposome) and the tyrosinase activity of BO fractions. The methanol extract of BO (BOM) was fractionated into five different partition layers: hexane (BOMH), ethylether (BOMEE), ethylacetate (BOMEA), butanol (BOMB) and aqueous (BOMA) layers. The antioxidant activities of BOM fractions toward oxidized DLPC-liposome were examined by spectrophotometry measuring oxidized conjugated dines. The antioxidant activities of BOMEE and BOMEA fractions toward oxidized DLPC-liposomes were similar to the antioxidant activities of $\alpha$-tocopherol and weaker than that of BHT. The synergy effects of antioxidation of BOMEE and BOMEA fractions added with vitamin C and $\alpha$-tocopherol had even stronger antioxidant activities than the fractions without vitamin C and $\alpha$-tocopherol. These results showed that the fractions of BOMEE and BOMEA could be developed as a potent antioxidant. Out of five different partition layers of BOM fractions, BOMEA exhibited the strongest tyrosinase activity of 94% at a concentration of 40 $\mu\textrm{g}$/mL. This result suggests BOMEA fractions inhibit the foramation of melanin and therefore can be used as the inhibitor of melanin synthesis. Results of antioxidant activity and tyrosinase inhibition indicate that useful bioactive substances exist in BOMEE and BOMEA fractions. Both fractions from BO (red cabbage) have the potential of being developed into health related products.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.91-97
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• 2008

What if the memory is not erased but continues to exist in the head as it was before? The typical answer to this question would be summarized as the "love for memory". It is almost unbearable that the memory is erased, forgotten or replaced with others. Even though three episodes may be understood as separate things, they have a different image when they are seen under one subject . he three episodes impresses the people with their unique fantastic images and artistic air. In the episode of , we can see a woman who is so much concerned with her past memory so that she does not love the present. In this episode, we can realize how much destructive the bad past memory gives effect on a woman and how memory can give bad effect on a person if that does not connect the past and the present. The work criticizes the society whichdoes not understand the current problems by depicting a person who is so preoccupied with the thing near that person only. shows that the dream is meaningless if people have the future dream without understanding what they really want. Theaudience is absorbed to each hero or heroin who is so obsessed with the past, present and future. What we can feel from these three works is the doubt about the human society which is so much preoccupied with the pessimism and the individuals who do not recognize the importance of the present because they are so much obsessed with their superficial past, present and future as well as the society where they live.

• Convergence Security Journal
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• v.12 no.1
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• pp.97-107
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• 2012

Our nation, of which the term of dispatching troops is winded up at the end of this year, is facing presidential election time including the nuclear security summit meeting in March, opening of EXPO in May, and the general election. Hence, the possibility to select our nation at the strategy forming public opinion of military withdrawal through Taliban's terror is high. It coincides with public affair strategy of Taliban terror and learning effect by the past cases. If the possibility of terror threat of Taliban along with this is summarized, the period of threat will concentrate on and be heightened in the first half when the nuclear security summit meeting and EXPO open in our nation, and target and method have high possibility of collision terror of bomb carrying vehicle and suicide bomb on national government organizations or American facilities, and etc, and possibility of kidnapping on our people such as oversea tourists, missionaries, and so on. Terror groups joining the criminal act is to use Islam illegal aliens who already acquire base in our nation or entry maneuver of specialized terrorists connected to Al-Qaeda. Pretext of such terror is withdrawal of our military and western allies stationed in Afghanistan. Therefore, publicity terror of Taliban against our people living overseas and security measure of international events such as the world nuclear security summit meeting, Yeosu EXPO, and etc in the first half of this year should be thoroughly prepared, domestic illegal aliens' movement should be comprehended, and measure blocking international terrorists' relating to Taliban infiltration into our nation should be sought for. Also, there is need of early announcement of government's political will on our military stationed in Afghanistan.

• Strategy21
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• s.39
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• pp.5-46
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• 2016

North Korea's 4th nuclear test on Jan. 6 and following developments once again awakened the world into seriousness of the nuclear matters on the Korean peninsula. On March 2, UNSC adopted Resolution 2270 which is complemented by Seoul government's measures such as withdrawal from the Gaesung Industrial Complex (Feb. 9) and announcement of unilateral sanction (March 8). Seoul government also strongly urged the international community to strangle North Korea's 'financial resources.' The U.S., Japan, China, and other countries have issued unilateral sanctions to complement the UNSC measure. South Korea and the U.S. conducted their annual joint military drill (Resolve-Foal Eagle) in the largest-ever scale. North Korea, however, responded with demonstration of its nuclear capabilities and announcement of de facto 'nuclear-first' politics. North Korea test-fired a variety of delivery vehicles, threatened nuclear strikes against South Korea and the U.S., and declared itself as an 'invincible nuclear power armed with hydrogen bombs' at the 7th Workers 'Party Congress held in May, 2016. Considering the circumstantial evidences, the North's 4th nuclear test may have been a successful boosted fission bomb test. North Korea, and, if allowed to go on with its nuclear programs, will become a nuclear power armed with more than 50 nuclear weapons including hydrogen bombs. The North is already conducting nuclear blackmail strategy towards South Korea, and must be developing 'nuclear use' strategies. Accordingly, the most pressing challenge for the international community is to bring the North to 'real dialogue for denuclearization through powerful and consistent sanctions. Of course, China's cooperation is the key to success. In this situation, South Korea has urgent challenges on diplomacy and security fronts. A diplomatic challenge is how to lead China, which had shown dual attitudes between 'pressure and connivance' towards the North's nuclear matters pursuant to its military relations with the U.S, to participate in the sanctions consistently. A military one is how to offset the 'nuclear shadow effects' engendered by the North's nuclear blackmail and prevent its purposeful and non-purposeful use of nuclear weapons. Though South Korea's Ministry of Defense is currently spending a large portion of defense finance on preemption (kill-chain) and missile defense, they pose 'high cost and low efficiency' problems. For a 'low cost and high efficiency' of deterrence, South Korea needs to switch to a 'retaliation-centered' deterrence strategy. Though South Korea's response to the North's nuclear threat can theoretically be boiled down into dialogue, sanction and deterrence, now is the time to concentrate on strong sanction and determined deterrence since they are an inevitable mandatory course to destroy the North' nuclear-first delusion and bring it to a 'real denuclearization dialogue.'

• Korean Security Journal
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• no.11
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• pp.61-86
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• 2006

Various terrorism in modern society against nation's dignitaries are constantly existing. They damage severely to the society and the nation's security, and they cause disorganizations of social and national rule orders. In order to provide the key figures' perfect protection, the threatening terroizing environment for primary leaders and the route of terrorism should be intercepted. Effective methods of these are summarized as follow. First, recent terrorism against the primary leaders are mostly assassinations, bomb attacks, and suicide bomb attacks, which terminate in a moment. Therefore, security service agents should keep in mind that protection is the best, and government's anti-terrorism agencies should develop policies and set the directions within a new paradigm to the advance anti-terrorism. Second, advance prevention activities against nation's VIP terrorism should be strengthened, such as strengthening security informational activities, constructing cooperative systems of domestic and international facilities, considering continuous system to prevent terrorism, and intensifying safety counterplans of human and material weak points. Third, international cooperative system should be set to apply economical and political sanctions to nations which support terror organizations in direct or indirect ways, and this system needs to strengthen the punishment against terrorists. Fourth, security systems to protect nation's primary leaders should complement, and developing programs for coping with the terrorism and establishing laws for anti-terrorism should be made. Also, educational training of agents who perform anti-terrorism duties should be strengthened, and scientific techniques and equipment for security should be made to protect primary leaders from terrorism.