• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.6
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• pp.1106-1112
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• 2010

One of the considerations in weapon systems procurement is the objective of maximizing the current force. Also, offensive effects, rather than defense are valued in weapons system development and procurement. Especially, the survivability of a naval ship is equally important as the offensive effect of onboard weapons. In case of naval ships, development of attack tactics and research regarding damage minimization must be conducted through live fire exercise against actual targets in order to minimize damage from the enemy. However, it is difficult to conduct such adequate measures due to realistic limitations such as time and budget in order to verify and calculate a weapon system's attack and damage effects along with the lack of practical studies in this subject despite numerous interests. Research are being conducted utilizing M&S to estimate attack effects and study damages due to such reason, but the lack of authoritative data and development ability are limiting calculation of reliable results. Therefore, this study will propose a measure to increase survivability of a weapon system(ship/vessel) utilizing research of vulnerability from enemy attacks analysis method against a naval ship(Craft Air Cushion).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.770-775
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• 2014

According to ICNIRP guidelines for limiting exposure to time-varying electric, magnetic and electromagnetic fields up to 300GHz, magnetic flux density which range from 3Hz to 150kHz are regulated to lower than $6.25{\mu}T$. In order to comply with its standard, OLEV(On-Line Electric Vehicle) have been designed considering EMF(Electro-Magnetic Field) reduction. However, if a current flowing in power line would be bigger for increasing power transfer efficiency, the established shield system no longer acts their role properly. In this paper, therefore, FCCL(Flexible Copper Clad Laminate) is applied to power line and pick-up devices to solve the problems. Though, the FCCL is normally utilized to insulator on circuit board, because of its high heat resistance characteristic, flexibility and thin properties, it makes effectiveness in the shielding device as well. 4 types of FCCL shielding structure are introduced to power line and pick-up devices. From the results, the FCCL which are placed in proposed positions shows maximum EMF reduction compared to the established shielding structure. Henceforth, if OLEV is applied FCCL shielding structure in practice, it will not only be more safe but also step forward to commercialization near future.

• The KIPS Transactions:PartC
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• v.13C no.1 s.104
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• pp.35-44
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• 2006

Current technologies on digital rights management (DRM) have focused on security and encryption as a means of solving the issue of unauthorized copying, that is, locking the content and limiting its distribution to only purchasers. But, illegal content copy should be protected not only from purchasers but also from other principals such as media distributors and content providers. In this paper, we designed and implemented end-to-end digital lights management system that can cover a content protection on the overall value-chains of content distribution. Proposed system provides content protection and secure management of digital rights in creator, provider, and distributor like in purchaser. Accordingly it can provide an environment protecting each principal's digital rights and prohibiting illegal usage of content.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1711-1713
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• 2000

We fabricated an IMI-O polymer containing an imidazole group that could form a complex structure between the monolayer and the metal ions at the air-water interface. Also, the surface analysis and the electrical properties of metal ion complex of Langmuir-Blodgett (LB) films were investigated by using $\pi$-A isotherms. Atomoic force microscopy (AFM), current-voltage (I-V) measurements. In the $\pi$-A isotherms the molecular area was expanded with $Fe^{3+}$ concentration increase. It is considered that the expansion of molecular area is due to electrostatic repulsion between the polymer chains and hydrophobic increase of ionic strength. In the I-V characteristics, it is found that the limiting area has effects on the change of conductivity. And, the dielectric relaxation time decreased for increase of the $Fe^{3+}$ concentration.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1322-1327
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• 2004

In the present work, a series of experiments have been performed on electro-hydrodynamic atomization of non-conducting liquid using a charge injection type nozzle. Effects of liquid flow rate, input voltage, and distance between the needle and the ground electrode (nozzle-embedded metal plate) have been examined. For fixed electrode distances, total and spray currents increase with increase of liquid flow rate and input voltage. When the distance between the needle and the ground electrode becomes closer, total, leakage and spray current increase, but the onset voltage for dielectric breakdown decreases. When the electric field strength of the liquid jet exceeds that for the air breakdown, a portion of the electric charges in the liquid jet is dissipated into the ambient air, and the charge density shows a limiting value. Atomization quality can be improved by increasing the flow rate because the higher charge density is achieved with the larger liquid velocity in addition to the enhanced aerodynamic effect.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2138-2139
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• 2005

We demonstrate a simple CO2 laser by controlling firing angle of a TRIAC switch in ac power line. The power supply for our laser system switches the voltage of the AC power line (60Hz) directly. The power supply does not need elements such as a rectifier bridge, energy-storage capacitors, or a current-limiting resistor in the discharge circuit. In order to control the laser output power, the pulse repetition rate is adjusted up to 60Hz and the firing angle of TRIAC gate is varied from 45 to 135. A ZCS(Zero Crossing Switch) circuit and a PIC one-chip microprocessor are used to control the gate signal of the TRIAC precisely. The maximum laser output of 40W is obtained at a total pressure of 18Torr, a pulse repetition rate of 60Hz, and a TRAIC gate firing angle of 90.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.767-775
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• 2014

New material design has obtained tremendous attention in material science community as the performance of new materials, especially in nano length scale, could be greatly improved to applied in modern industry. In certain conditions limiting experimental synthesis of these new materials, new approach by computer simulation has been proposed to be applied, being able to save time and cost. Recent development of computer systems with high speed, large memory, and parallel algorithms enables to analyze individual atoms using first principle calculation to predict quantum phenomena. Beyond the quantum level calculations, mesoscopic scale and continuum limit can be addressed either individually or together as a multi-scale approach. In this article, we introduced current endeavors on material design using analytical theory and computer simulations in multi-length scales and on multi-physical properties. Some of the physical phenomena was shown to be interconnected via a cross-link rule called 'cross-property relation'. It is suggested that the computer simulation approach by multi-physics analysis can be efficiently applied to design new materials for multi-functional characteristics.

• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.313-317
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• 2018

Licenses for the storage of spent nuclear fuel (SNF) and vitrified highly active waste in casks under dry conditions are limited to 40 years and have to be renewed for prolonged storage periods. If such a license renewal has to be expected since as in accordance with the new site selection procedure a final repository for spent fuel in Germany will not be available before the year 2050. For transport and possible unloading and loading in new casks for final storage, the integrity and the maintenance of the geometry of the cask's inventory is essential because the SNF rod cladding and the cladding of the vitrified highly active waste are stipulated as a barrier in the storage concept. For SNF, the cladding integrity is ensured currently by limiting the hoop stress and hoop strain as well as the maximum temperature to certain values for a 40-year storage period. For a prolonged storage period, other cladding degradation mechanisms such as inner and outer oxide layer formation, hydrogen pick up, irradiation damages in cladding material crystal structure, helium production from alpha decay, and long-term fission gas release may become leading effects driving degradation mechanisms that have to be discussed.

• The Plant Pathology Journal
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• v.33 no.4
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• pp.351-361
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• 2017

Bacterial canker is the largest limiting factor in the cultivation and production of kiwifruit worldwide. Typical symptoms comprise necrotic spots on leaves, canker and dieback on canes and trunks, twig wilting, and blossom necrosis. Pseudomonas syringae pv. actinidiae (Psa), which is the causal agent of kiwifruit bacterial canker, is divided into four biovars based on multilocus sequence analysis of different genes, additional PCR testing of pathogenic genes (argKtox cluster, cfl, and various effector genes), and biochemical and physiological characterization. Bacterial canker caused by Psa biovar 2 designated Psa2 was detected for the first time on the green-fleshed kiwifruit cultivar Hayward in 1988 and the yellow-fleshed kiwifruit cultivar Hort16A in 2006 in Korea. Psa biovar 3 designated Psa3, responsible for the current global pandemics of kiwifruit bacterial canker, began to appear in Korea in 2011 and caused tremendous economic losses by destroying many vines or orchards of yellow-fleshed kiwifruit cultivars in one or several growing seasons. Bacterial canker epidemics caused by both Psa2 and Psa3 are prevalent in Korea in recent years. In this review, we summarize the symptomatology, etiology, disease cycle, diagnosis, and epidemiology of kiwifruit bacterial canker in Korea.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2011.11a
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• pp.7-10
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• 2011

The semi-arid and arid regions comprise almost 40 percent of the world's land surface. The low and erratic precipitation pattern is the single most significant contributor for limiting crop production in such regions where rainfall is the source for surface, soil and ground water. In a changing climate, the semi-arid and arid regions would increasingly face the challenge of water scarcity. According to the relevant literature; under the assumption of a doubling of the current atmospheric CO2 concentration, irrigation demand was estimated to increase for wheat and to decrease for second crop maize in a Mediterranean environment of Turkey in the 2070s. Crop evapotranspiration would decrease due to stomata closure. Reference evapotranspiration and potential soil evaporation were projected to increase by 8.0 and 7.3%, respectively, whereas actual soil evaporation was predicted to decrease by 16.5%. Drainage losses below 90 cm soil depth were found to decrease mainly due to lesser rainfall amount in the future.