• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.2
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• pp.39-47
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• 2008

Among previous Side Channel Analysis (SCA) methods, Differential Power Analysis (DPA) based on the statistical characteristics of collected signals has been known as an efficient attack for uncovering secret key of cryptosystems. However, the attack performance of this method is affected very much by the temporal misalignment and noise of collected side channel signals. In this paper, we propose a new method to surmount the noise problem in DPA. The performance of the proposed method is then evaluated while analyzing the power consumption signals of Micro-controller chips during a DES operation. Its performance is then compared to that of the original DPA in the time and frequency domains. When we compare the experimental results with respect to the needed number of traces to uncover the secret key, our proposed method shows the performance enhancement 33% in the time domain and 50% in the frequency domain.

• The Journal of the Acoustical Society of Korea
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• v.43 no.2
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• pp.225-233
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• 2024

Active sonar transmits sound waves to detect covertly maneuvering underwater objects and detects the signals reflected back from the target. However, in addition to the target's echo, the active sonar's received signal is mixed with seafloor, sea surface reverberation, biological noise, and other noise, making target recognition difficult. Conventional techniques for detecting signals above a threshold not only cause false detections or miss targets depending on the set threshold, but also have the problem of having to set an appropriate threshold for various underwater environments. To overcome this, research has been conducted on automatic calculation of threshold values through techniques such as Constant False Alarm Rate (CFAR) and application of advanced tracking filters and association techniques, but there are limitations in environments where a significant number of detections occur. As deep learning technology has recently developed, efforts have been made to apply it in the field of underwater target detection, but it is very difficult to acquire active sonar data for discriminator learning, so not only is the data rare, but there are only a very small number of targets and a relatively large number of non-targets. There are difficulties due to the imbalance of data. In this paper, the image of the energy distribution of the detection signal is used, and a classifier is learned in a way that takes into account the imbalance of the data to distinguish between targets and non-targets and added to the existing technique. Through the proposed technique, target misclassification was minimized and non-targets were eliminated, making target recognition easier for active sonar operators. And the effectiveness of the proposed technique was verified through sea experiment data obtained in the East Sea.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.136-146
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• 2013

In this paper, the residual delay compensation algorithm is proposed for FX-type KJJVC. In case of initial version as that design algorithm of KJJVC, the integer calculation and the cos/sin table for the phase compensation coefficient were introduced in order to speed up of calculation. The mismatch between data timing and residual delay phase and also between bit-jump and residual delay phase were found and fixed. In final design of KJJVC residual delay compensation algorithm, the initialization problem on the rotation memory of residual delay compensation was found when the residual delay compensated value was applied to FFT-segment, and this problem is also fixed by modifying the FPGA code. Using the proposed residual delay compensation algorithm, the band shape of cross power spectrum becomes flat, which means there is no significant loss over the whole bandwidth. To verify the effectiveness of proposed residual delay compensation algorithm, we conducted the correlation experiments for real observation data using the simulator and KJJVC. We confirmed that the designed residual delay compensation algorithm is well applied in KJJVC, and the signal to noise ratio increases by about 8%.

• Journal of Arbitration Studies
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• v.21 no.3
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• pp.89-114
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• 2011

Environmental disputes not only possess the special characteristics of collectivity and plural value relativity but it also possesses the unique features of difficulty to prove cause and effect as well as the structural maldistribution of evidence and information. Therefore, the positive resolution of an environmental dispute can be brought about more easily with the Alternative Dispute Resolution (ADR) which can take the form of talks, compromises, as well as arbitration or mediation rather than through a trial process. Such being the case, this paper first looks into the problems and effectiveness of the arbitration system of environmental lawsuits and then takes an even closer look at Korea's environmental dispute arbitration system and finally offer some reform methods. In Korea, the environmental dispute arbitration system was implemented in 1991 and has been executed since then. Although this system does have positive features such as the high rate of coming to an agreement between the involved parties but unfortunately, most of the cases rely on decisions based on right and wrong which cannot but be far away from the intentions of the ADR system. It is heavily centered around claims regarding psychological compensation regarding noise and vibrations and the ratio of the actual amount of compensation is comparatively lower than the requested amount. In addition, with the limits in organization and manpower, it leads to a lack of professionalism as well as the problem of low usage with the low awareness rate. As reform measures against the aforementioned problems, this paper suggests the following. First, in order to activate the arbitration process more fully, it proposes aggressive usage of compulsory arbitration as well as submission to arbitration, while at the same time raising ADR professionals to fill in the missing gaps. Secondly, in order to overcome the problem of concentration of related cases, making representative lawsuits of environmental organizations would be a good idea. It also states that in order to make the compensation amount more realistic, it should go out of the across-the-board decision making process and reach a decision about the compensation amount that takes the individual situation's dispute into consideration. In order to boost the professionalism of the environmental dispute arbitration, it is necessary to reform the organization and manpower such as expanding the number of members of full standing, and increasing the professionalism of the examiners. Also, to increase the usage rate of the ADR system, the paper suggests stationing a civilian consultant regarding environment, or activating the compulsory arbitration which is the premise for public participation on the part of the residents.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.957-964
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• 2016

Acquisition of reliable depth maps is a critical requirement in many applications such as 3D videos and free-viewpoint TV. Depth information can be obtained from the object directly using physical sensors, such as infrared ray (IR) sensors. Recently, Time-of-Flight (ToF) range camera including KINECT depth camera became popular alternatives for dense depth sensing. Although ToF cameras can capture depth information for object in real time, but are noisy and subject to low resolutions. Recently, filter-based depth up-sampling algorithms such as joint bilateral upsampling (JBU) and noise-aware filter for depth up-sampling (NAFDU) have been proposed to get high quality depth information. However, these methods often lead to texture copying in the upsampled depth map. To overcome this limitation, we formulate a convex optimization problem using higher order regularization for depth map upsampling. We decrease the texture copying problem of the upsampled depth map by using edge weighting term that chosen by the edge information. Experimental results have shown that our scheme produced more reliable depth maps compared with previous methods.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.178-188
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• 2015

This study has the main objective of being of help as a reference data for the application of the finishing materials when designing the interior of the chapel of the church space through analysis of the finishing materials against the chapels of church space which has complex function. As precedent studies for this, the composition of the function and concept of the church space was surveyed and the complex function of the church space was surveyed. The theoretical surveyed was performed according to the casual composition, behavior of the community and role and location of the duties of the church members. The case objects were 10 chapels constructed by 5 professional interior design companies. The content of the analysis was the finishing materials in the chapels and their application characteristics. The detailed considerations to be referred to when designing the interior of the chapels of church space in the future were proposed. The analysis result of the application of the finishing materials according to the locational function of the chapels of church space can be explained as follows. First, the platform area was the characteristic of applying finishing materials which induce visual immersion. As for the floor materials in the platform, in order to minimize the floor sound and vibration phenomenon occurring during movements, noise insulation and dust protection rubber sheet was place and on top of it the floor or the carpet was placed. Second, the Choir area had the difficult problem of having to consider the appropriate sound absorption occurring due to the proliferation of sound and performance of classical instruments at the same time. However, in the case, this problem was solved through the sculptures of convex shape. Third, since the scheelite is a space where many people move around, the finishing material which absorbs sound was mainly used. Fourth, the entrance area was composed of thick wall materials compared to other walls, and the sound absorption character was most significantly considered when applying the finishing material. Fifth, the broadcasting room was composed either in independent type or an open type and performed its function and the main finishing materials was transparent glass which was highest use frequency.

• Journal of Advanced Navigation Technology
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• v.6 no.1
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• pp.17-26
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• 2002

In this paper, we have analyzed the BER (Bit Error Rate) performance of multi-user detectors employing SIC(Successive Interference Cancellation) and PIC (Parallel Interference Cancellation) which are the representative schemes in the subtractive interference cancellation. We have considered the MUD structure employing HIC (Hybrid Interference Cancellation) which combines SIC with PIC scheme, and then analyzed the BER performance. We have evaluated the BER performance of SIC and HIC schemes which execute the soft decision to generate the tentative data bit for the purpose of the interference cancellation in MAI and noise environments. Through the numerical analysis and computer simulation, it is shown that HIC can remove the effect of MAI more efficiently than the others, that improve the BER performance and increase the capacity of DS-CDMA systems regardless of the power control conditions. The reason is that the SIC scheme in front of HIC can solve the near-far problem caused by the imperfect power control and PIC scheme in the rear of it can improve the performance much more.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.23-31
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• 2011

The simple bacteria cooperative optimization (sBCO) algorithm that we developed as one of optimization algorithms has shown relatively good performances, but their performances were limited by step-by-step movement of individuals at a time. In order to solve this problem, we proposed a new method that assigned a speed to each individual according to its rank and it was confirmed that it improved the performances of sBCO in some degree. In addition to the assigning of speed to the individuals, we employed a new mutation operation that most existing evolutionary algorithms used in order to enhance the performances of sBCO in this paper. A specific percent of bad individuals are mutated within an area that is proportion to the rank of the individual in the mutation operation. That is, Gaussian noise of large standard deviation is added as the fitness of individuals is low. From this, the probability that the individuals with lower ranks can be located far from its parent will be increased. This causes that the probability of falling into local optimum areas is decreased and the probability of fast escaping the local optimum areas is increased. From experimental results with four function optimization problems, we showed that the performances of sBCO with mutation operation and individual speed were increased. If the optimization function is quite complex, however, the performances are not always better. We should devise a new method for solving this problem as a further work.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.34-37
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• 2017

In recent emerging industry, Display field becomes bigger and bigger, and also semiconductor technology becomes high density integration. In Flat Panel Display, there is an issue that electrostatic phenomenon results in fine dust adsorption as electrostatic capacity increases due to bigger size. Destruction of high integrated circuit and pattern deterioration occur in semiconductor and this causes the problem of weakening of thermal resistance. In order to solve this sort of electrostatic failure in this process, Soft X-ray ionizer is mainly used. Soft X-ray Ionizer does not only generate electrical noise and minute particle but also is efficient to remove electrostatic as it has a wide range of ionization. X-ray Generating efficiency has an effect on soft X-ray Ionizer affects neutralizing performance. There exist variable factors such as type of anode, thickness, tube voltage etc., and it takes a lot of time and financial resource to find optimal performance by manufacturing with actual X-ray tube source. MCNPX (Monte Carlo N-Particle Extended) is used for simulation to solve this kind of problem, and optimum efficiency of X-ray generation is anticipated. In this study, X-ray generation efficiency was measured according to target material thickness using MCNPX under the conditions that tube voltage is 5 keV, 10 keV, 15 keV and the target Material is Tungsten(W), Gold(Au), Silver(Ag). At the result, Gold(Au) shows optimum efficiency. In Tube voltage 5 keV, optimal target thickness is $0.05{\mu}m$ and Largest energy of Light flux appears $2.22{\times}10^8$ x-ray flux. In Tube voltage 10 keV, optimal target Thickness is $0.18{\mu}m$ and Largest energy of Light flux appears $1.97{\times}10^9$ x-ray flux. In Tube voltage 15 keV, optimal target Thickness is $0.29{\mu}m$ and Largest energy of Light flux appears $4.59{\times}10^9$ x-ray flux.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.102-109
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• 2019

This paper describes the design of the circuit card assembly to eliminate the communication error on a servo control unit installed in the automated resupply vehicle K56. K56 is a weapon system that automates the supply and loading of ammunition on the K-55A1 self-propelled artillery. As the core item responsible for ammunition movement control, the servo control unit is required to have good communication stability and reliability, but the conventional unit has recognized a problem that communication error intermittently occurs, resulting in an emergency stop phenomenon. We analyzed the communication signal of the servo control unit and identified the failure cause of the circuit card assembly to solve this problem. In addition, the signal interference in data/address line of the circuit card assembly was confirmed through analysis of the failure cause, and redesigned to avoid the interference, such as adjustment of the distance between communication lines and position change. Finally, the proposed cause analysis and redesign were verified through the component of servo control unit and attachment test on K56. We expected these study results to be used as reference for the design of other similar items.