• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.93-101
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• 2008

Side channel attacks are well known as one of the most powerful physical attacks against low-power cryptographic devices and do not take into account of the target's theoretical security. As an important succeeding factor in side channel attacks (specifically in DPAs), exact time-axis alignment methods are used to overcome misalignments caused by trigger jittering, noise and even some countermeasures intentionally applied to defend against side channel attacks such as random clock generation. However, the currently existing alignment methods consider only on the position of signals on time-axis, which is ineffective for certain countermeasures based on time-axis misalignments. This paper proposes a new signal alignment method based on interpolation and decimation techniques. Our proposal can align the size as well as the signals' position on time-axis. The validity of our proposed method is then evaluated experimentally with a smart card chip, and the results demonstrated that the proposed method is more efficient than the existing alignment methods.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.3
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• pp.23-32
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• 2001

Since the LILI-128 cipher is a clock-controlled keystream generator, the speed of the keystream data is degraded in a clock-synchronized hardware logic design. Basically, the clock-controlled $LFSR_d$ in the LILI-128 cipher requires a system clock that is 1 ~4 times higher. Therefore, if the same clock is selected, the system throughput of the data rate will be lowered. Accordingly, this paper proposes a 4-bit parallel $LFSR_d$, where each register bit includes four variable data routines for feed feedback of shifting within the $LFSR_d$ . Furthermore, the timing of the propose design is simulated using a $Max^+$plus II from the ALTERA Co., the logic circuit is implemented for an FPGA device (EPF10K20RC240-3), and the throughput stability is analyzed up to a late of 50 Mbps with a 50MHz system clock. (That is higher than the 73 late at 45 Mbps, plus the maximum delay routine in the proposed design was below 20ns.) Finally, we translate/simulate our FPGA/VHDL design to the Lucent ASIC device( LV160C, 0.13 $\mu\textrm{m}$ CMOS & 1.5v technology), and it could achieve a throughput of about 500 Mbps with a 0.13$\mu\textrm{m}$ semiconductor for the maximum path delay below 1.8ns.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.801-807
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• 2021

In various industrial fields and infrastructure based on electronic components, such as communication equipment, transportation, computer networks, and military equipment, the need for electromagnetic pulse shielding has increased. Two methods for applying electromagnetic pulse shielding are effective. The first is construction using shielding materials, such as shielding concrete, shielding doors, and shielding windows. The other is coating shielding paints on non-shielding structures. Electromagnetic pulse shielding paints are made using conductive materials, such as carbon nanotubes, graphite, carbon black, and carbon fiber. In this paint, electromagnetic pulse shielding performance is added to the commonly used water-based paint. In this study, the shielding effectiveness and bonding performance of paints using conductive graphite and carbon black as shielding materials were evaluated to develop electromagnetic pulse shielding inorganic paints. The shielding effectiveness and bonding performance were evaluated by applying six mixtures composed of different kinds and amounts of shielding material. The mixture of conductive graphite and carbon black at a weight ratio of 1:0.2 was the most effective in shielding as 33.6 dB. Furthermore, the mixture produced using conductive graphite only showed the highest bonding performance of 1.06 MPa.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.1
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• pp.1-12
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• 2022

Wind tunnel test for a small scale electric ducted fan with a 104mm diameter was conducted to analyze the aerodynamic characteristics when it was used as a propulsion system of tilt-propeller UAV. Experimental conditions were derived from flight conditions of a sub-scaled OPPAV. Forces and moments of the ducted fan model were measured by a 6-axis balance and 3-dimensional wake vectors which could induce an aerodynamic influence in the vehicle were measured by 5-hole probes. Thrust and torque on hover and cruise conditions were measured and analyzed to drive out the operating conditions when it was applied in the sub-scaled OPPAV. On transition conditions, thrust keep its value with tilt angle variation below 40° and increase after that. But, sideforce increase constantly until 75°. The maximum axial velocity in the wake on hover and cruise conditions was around 60m/s and tangential velocity was around 12m/s. The position of the maximum axial velocity and vortex center move off the fan rotation center line as the tilt angle increases.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.765-778
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• 2021

The purpose of this study is to prevent fire accidents in advance by deriving prior knowledge among groups about temporary fire-fighting facilities of workers at construction sites and devising appropriate improvement measures. The findings are as follows.First, in the case of fire extinguishers, statistical attention was paid to the contractor, supervisor, partner worker and fire extinguisher manager between designations. 87% of fire managers and 70% of facility supervisors said fire extinguisher management managers needed to be designated for each type of construction, which requires designation of fire extinguisher management managers, frequently checking and relocating. Second, in the case of simple fire extinguishing facilities, statistical attention was paid to the application of penalties for unauthorized use of fire extinguishing facilities with construction companies, supervisors, and business partners.Third, in the case of emergency alarm measures, statistical attention was paid to the application of emergency alarm sound to temporary broadcasting facilities with construction works, supervisors, and business partners.Fourth, in the case of induction, statistical attention was paid to the application of connection between construction works, supervisors, and partner workers, such as passage guidance, emergency lighting, etc.It was found that 65% of construction workers and 55% of electrical workers had different applications such as aisle guidance and emergency lighting for each type of business partner. In order to resolve blind spots such as evacuation zone guidance due to the structure of the building, it is necessary to easily distinguish the direction of the entrance door from a long distance by applying it in conjunction with passage guidance lights and emergency lighting.

• Journal of Advanced Navigation Technology
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• v.26 no.2
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• pp.99-104
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• 2022

Recently, the domestic demand for weapon systems based on aircraft platforms is gradually increasing. In particular, the demand for effective precision guided missile(PGM) which cruises for several hundred kilometers after launch to strike the ground target is rising drastically, but it is in the early stages of development, and research based on it are limited. This paper is a study on the power converter unit(PCU) within PGM which is mounted on an aircraft platform based on MIL-STD-1760, which is an interface between an aircraft and PGM. We investigated the electrical properties and structure of the umbilical connector, and the aircraft/store electrical interconnection system. Also, the focus on the design specifications of the PCU that supplies power were described. This result 3 phase AC input, which is the state for the guided simulation power supply in the state of being mounted on an aircraft that rectification method with power factor correction(PFC) compared to bridge rectifier circuit. In the future, it may be used as a basis for power supply design on aircraft mounted weapon systems.

• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.325-330
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• 2022

Distichiasis is one of the diseases commonly encountered in companion animals, and these abnormal eyelashes cause corneal ulcers, continuous eye irritation, eye pain, glare, epiphora, foreign body sensation and can cause corneal opacity and vision loss in severe cases. In this study, an eyelash epilation needle for animals was developed and applied to a real case, and the results were observed. In a case of corneal ulcer caused by distichiasis of a 2-year-old Shih Tzu, a high-frequency surgical instrument for animals was converted into an electric epilation needle to attempt a procedure to destroy the eyelash hair follicles on the upper eyelid. A epilation needle was developed to have a diameter of 0.1 mm and a length of 4 mm at the end of the handle of DOCTANZ 400, an electrosurgical instrument for animals only. In the procedure, 2~3 mm of an epilation needle was inserted into the hair follicle, and 1 watt of electric power was applied to the hair follicle for about 5 sec. to carry out electrolysis until white bubbles were generated around the meibomian glands thereby destroying the hair follicle. As a result, no eyelashes grew any longer in the treated area indicating that the treatment was successful. It is hoped that the method developed in this study will be applied so that it will be widely used as a treatment method for distichiasis in companion animals that can be frequently seen hereafter.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.3
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• pp.110-115
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• 2023

During the Hg₂Br₂ physical vapor transport process, with increasing the partial pressure of component B, P_B from 40 Torr to 200 Torr, a unicellular convective flow structures move from the crystal growth region to the center region in the vapor phase. The boundary layer flow is dominant for P_B = 40 Torr, and the core region flow is dominant for P_B = 200 Torr. The flow in the vapor phase shows a three-dimensional convective flow structure with a single cell (unicellular) for P_B = 40 Torr and 200 Torr, exhibits an asymmetrical flow with respect to the x, y central axis under the horizontally oriented configuration with an aspect ratio (length-to-width) of 3 and linear conducting walls. The critical temperature difference between the source and crystal region is about 30 K. The total molar flux of Hg₂Br₂ increases with the temperature difference until the total molar flux reaches the critical value. At the critical total molar flux, the total molar flux abruptly decreases.

• The Journal of Bigdata
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• v.6 no.2
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• pp.1-15
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• 2021

The unprecedented pandemic of infectious diseases called COVID-19 has dampened human and material movement, and changes in the global economic structure have caused various economic and industrial problems such as worsening employment along with the domestic and international economic recession. In this crisis situation, the government announced the "New Deal" as a new card to enhance economic vitality following the "emergency disaster support fund." This means that the first business of the Digital New Deal, the beginning and core of the New Deal, begins digital transformation from collecting data, which is the "rice" of digital transformation to the data dam. Until now, not only the government but also local governments have established and operated platforms for collecting and sharing public data by establishing various data portals. It is evaluated that it lacks utilization for commercialization as not only the government but also local governments focus only on building the platform without considering the business model when building the initial public data platforms. In particular, in the case of regions, there is a lack of public data to be used for data business, so it is necessary to utilize data from public institutions in the region. In this study, various data collection, data quality improvement, and data utilization improvement were suggested as measures to solve these problems.

• Journal of The Geomorphological Association of Korea
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• v.18 no.3
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• pp.37-51
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• 2011

Geomorphic changes and sedimentary changes are investigated by sediment analysis from estuarine tidal flat, Mosan Bay Estuary, which is a tide-dominated and rias estuary. Sediments separatedly deposited during the early Holocene and the late Holocene. There are unconformities between the early Holocene sediment unit and the late Holocene sediment unit. Developments of these unconformities were related with fluctuated sea level change during the mid Holocene. Three deposit zones are spatially classified, which are named "intermittent tide channel deposit zone"(A1, B1, D3), "flood-dominated deposit zone"(A3, B3, C1, C3), and "fluvial sediment deposit zone"(A2, B2). This classification is explained by three main effects; laterally restricted migration of a tidal channel, diffract flood effect and settling lag effect, and fluvial induced reworking. These effects are deserved as main factors which have formed estuarine geomorphology in tidedominated and rias estuary. This study suggests research directions in reconstructing estuarine geomorphic and sedimentary change in west coast of Korea. Furthermore, it gives useful data for making a "land-ocean interaction" model for west coast of Korea.