• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.491-501
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• 2019

In side-channel analysis, which exploit physical leakage from a cryptographic device, deep learning based attack has been significantly interested in recent years. However, most of the state-of-the-art methods have been focused on classifying side-channel information in a profiled scenario where attackers can obtain label of training data. In this paper, we propose a new method based on deep learning to improve non-profiling side-channel attack such as Differential Power Analysis and Correlation Power Analysis. The proposed method is a signal preprocessing technique that reduces the noise in a trace by modifying Auto-Encoder framework to the context of side-channel analysis. Previous work on Denoising Auto-Encoder was trained through randomly added noise by an attacker. In this paper, the proposed model trains Auto-Encoder through the noise from real data using the noise-reduced-label. Also, the proposed method permits to perform non-profiled attack by training only a single neural network. We validate the performance of the noise reduction of the proposed method on real traces collected from ChipWhisperer board. We demonstrate that the proposed method outperforms classic preprocessing methods such as Principal Component Analysis and Linear Discriminant Analysis.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.49-56
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• 2011

Recently, the ground injection method using water glass as one of the components of the main resources and the products of the construction has some basic problems for permanent reinforcement of foundation and stopping leakage of water because it has some serious problems such as durability reduction, compression strength reduction and eluviation. This study was to evaluate the environmental impact and durability of the developed friendliness of Natural and Durable Stabilizer(NDS) of inorganic injection and Space Grouting Roket(SGR) with typical water glass type material. Two materials, NDS and SGR, were compared with each other by unconfined compressive strength test, fish poison test, durability test and triaxial permeability test. The results of the durability test indicated that the 28-day strength of the NDS was 1.5 times higher than that of the SGR. The fish poison test proved that the survival rate in the SGR and NDS is 50~70%, and 100%, respectively. Therefore, the NDS has higher survival rate than that of the existing SGR. The NDS will be considered by an environmentally friendly product and moreover it has a few problems for soil and groundwater pollution.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.273-280
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• 2024

In this study, the antibacterial activity and mechanisms of bitter orange extract, a natural antibacterial agent, were investigated, with a focus on its potential application in washing water for controlling Salmonella Typhimurium contamination of salad, a ready-to-eat food. The minimum inhibitory concentration (MIC) of bitter orange extract against S. Typhimurium was determined using the broth dilution method. Subsequently, S. Typhimurium was exposed to various concentrations of bitter orange extract (1/16 MIC-2 MIC) and growth curves were measured. Following treatment with bitter orange extract, we investigated its antibacterial mechanism by measuring intracellular reactive oxygen species (ROS) levels, alterations in membrane potential and integrity, and nucleic acid leakage in S. Typhimurium. Additionally, salads artificially contaminated with S. Typhimurium were treated with different concentrations of bitter orange extract using the dipping method for various durations to assess the reduction effect. The MIC of bitter orange extract against S. Typhimurium was 195.313 mg/L, and bacterial growth was completely inhibited at a concentration of 1 MIC. Furthermore, an increase in bitter orange extract concentration correlated with elevated intracellular ROS levels, membrane potential disruption, membrane damage, and nucleic acid release. Importantly, salads treated with bitter orange extract exhibited a significant reduction in S. Typhimurium counts compared to the control, and prolonged treatment times resulted in further reductions in bacterial counts. Bitter orange extract was more effective than sodium hypochlorite and can be used as a safer salad wash. These findings indicate the potential treatment of salads to prevent foodborne illnesses.

• The Journal of Engineering Geology
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• v.13 no.2
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• pp.239-256
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• 2003

The purpose of this study is to investigate the hydrochemical characteristics of emergency-use groundwater in the Daejeon area, and to elucidate the contamination source of $NO_3-N$ and the origin of sulfate in the groundwater. The groundwater shows weak acidic pH, the electrical conductivity ranging from 142 to $903{\;}\mu\textrm{S}/cm$, and the hydrochemical types of $Ca-HCo_3$ and $Ca-Cl(SO_4,{\;}NO_3)$. The Box-Whisker analysis and the Krigging analysis of chemical data of groundwater were made to demonstrate the concentration distribution of hydrochemical composition, and to compare the trend of hydrochemical data. The groundwater in the area of Dong-gu, Jung-gu and Daeduk-gu, where are old town, shows higher electrical conductivity, nitrate content, sulfate and $EpCO_2$ levels than groundwater in new town area of Seo-gu and Yusung-gu. ${\delta}^{15}N$ of groundwater in the area of Seo-gu and Yusung-gu ranges from +7.4 to $+9.6{\textperthousand}$, indicating that major contamination source of $NO_3-N$ is the leakage from municipal sewage pipe lines. ${\delta}^{15}N$ of groundwater in the old town area of Tong-gu, Jung-gu and Daeduk-gu shows the range between +10.2 and $+23.5{\textperthousand}$, meaning that major contamination source is leakage of septic tank. ${\delta}^{34}S$ of groundwater shows the range of $+3~13.4{\;}{\textperthousand}$. Sulfur isotope indicates the possibility of a sulfate reduction and the input of anthrophogenic source.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.153-165
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• 2014

Carbon dioxide capture and storage (CCS) technology is recognizing one of method responding the climate change with reduction of carbon dioxide in atmosphere. In Korea, due to its geological characteristics, sub-seabed geological $CO_2$ storage is regarded as more practical approach than on-land storage under the goal of its deployment. However, concerns on potential $CO_2$ leakage and relevant acidification issue in the marine environment can be an important subject in recently increasing sub-seabed geological $CO_2$ storage sites. In the present study effect data from literatures were collected in order to conduct an effect assessment of elevated $CO_2$ levels in marine environments using a species sensitivity distribution (SSD) various marine organisms such as microbe, crustacean, echinoderm, mollusc and fish. Results from literatures using domestic species were compared to those from foreign literatures to evaluate the reliability of the effect levels of each biological group and end-point. Ecological effect guidelines through estimating level of pH variation (${\delta}pH$) to adversely affect 5 and 50% of tested organisms, HC5 and HC50, were determined using SSD of marine organisms exposed to the $CO_2$-induced acidification. Estimated HC5 as ${\delta}pH$ of 0.137 can be used as only interim quality guideline possibly with adequate assessment factor. In the future, the current interim guideline as HC5 of ${\delta}pH$ in this study will look forward to compensate with supplement of ecotoxicological data reflecting various trophic levels and indigenous species.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.87-101
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• 2012

In gas industries, the potential risks of serious accidents have been increased due to high technology application and process complexities. Especially, in case of gas-related accidents, the extent of demage is out of control since gas plants handle and produce combustible, flammable, explosive and toxic materials in large amounts. The characteristics of this kind of disaster is that accident frequency is low, while the impact of damage is high, extending to the neighboring residents, environment and related industries as well as employees involved. The hydrogen gases treated important things and it used the basic material of chemical plants and industries. Since 2000, this gas stood in the spotlight the substitution energy for reduction of the global warming in particular however it need to compress high pressure(more than 150 bar.g) and store by using the special cylinders due to their low molecular weight. And this gas led to many times the fire and explosion due to leak of it. To reduce these kinds of risks and accidents, it is necessary to improve the new safety management system through a risk management after technically evaluating potential hazards in this process. This study is to carry out the quantitative risk assesment for hydrogen filling plant which are very dangerous(fire and explosive) and using a basic materials of general industries. As a results of this risk assessment, identified the elements important for safety(EIS) and suggested the practical management tools and verified the reliability of this risk assessment model through case study of accident.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.113-118
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• 2016

In this paper, a read-in integrated circuit (RIIC) for IR scene projectors (IRSPs) adopting a sub-frame control technique is proposed, which minimizes the reduction of the apparent temperature of the IR images projected from IRSPs operating at a frame rate of 30 Hz. The proposed sub-frame control technique significantly reduces the amount of scene data loss on capacitors, which is caused by leakage currents flowing through MOSFET switches during holding periods, by dividing a unit frame into 8 sub-frames and refreshing the same scene data for each sub-frame. A current-drive RIIC was designed for the higher apparent temperature of IR radiated from the emitter, and it receives the scene data as a form of analog voltages from an external DAC. A prototype chip with a $64{\times}32$ RIIC array was fabricated using Magnachip/SKhynix $0.35{\mu}m$ 2-poly 4-metal CMOS process, and the measured maximum output data current is $230.3{\mu}A$. This amount of current ensures the projection of IR images whose maximum apparent temperature is $366.2^{\circ}C$ in the mid-wavelength IR (MWIR) when applied to a prototype emitter having a resistance of $15k{\Omega}$.

• The korean journal of orthodontics
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• v.24 no.1 s.44
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• pp.37-62
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• 1994

This study was undertaken to investigate the three dimensional vascular changes of periodontal ligament following orthodontic tooth movement. Experimental tooth movement was carried out in 96 Sprague-Dawley rats with the weight of 250g. They were divided into four experimental groups (each 24 rats). The left maxillary first molar was moved mesially with 25g force in group I, and with 75g force in group II. Each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days. In group III, 25g mesial force was applied for 3 days, and in group IV, 75g mesial force was applied for 3 days. Then the appliances were removed, and each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days from removal of appliance. The contralateral molars were used for control group. Casting media was injected via left ventricle and polymerized in warm water. After corrosion of surrounding soft tissue, three dimensional vascular changes were examined using scanning electron microscopy. The findings of this study were as follows: 1. Pressure side of group I and II showed degenerative vascular changes such as vascular compression, reduction of vasculature, leakage of casting media. But, regenerative changes were dominant after 7 days of tooth movement. Although the degenerative vascular changes were more severe in group II, which was exposed to heavy force, the timing of these changes was not different between two groups. 2. Periodontal vasculature was reestablished by the growth of new capillaries and their differentiation and union from the remaining periodontal vessels and vessels of alveolar bone marrow. Although vascular regeneration was more rapid in group I, which was exposed to light force, the vasculature was not fully normalized in both groups even after 21 days. 3. There was no remarkable changes in tension side of group I and II, but looping of capillary, new capillary growth, dilation of vessels, redirection of vessels in the direction of tensile force were occurred. 4. In pressure side of group III and IV, in which appliance was removed after 3 days of orthodontic force, bone resorption was continued even after removal of appliance. Regeneration of vasculature was initiated after 1-6 hours, and it was more rapid in group III than group IV. In both groups, the vasculature was not fully normalized even after 21 days. 5. After removal of appliance, tension side of group III and IV showed vascular compression and loss of vasculature.

• Journal of Veterinary Clinics
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• v.28 no.6
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• pp.555-561
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• 2011

Laparoscopic surgery is a well-established alternative to open surgery across disciplines. However, in veterinary medicine, laparoscopic surgery in dogs was rarely reported because of small abdominal size for multiple ports insertion. The concept of single-incision laparoscopic surgery (SILS) is to perform the entire laparoscopic operation through a single incision rather than conventional multiple small skin incisions. Indirect evidence of potential benefits of SILS, decreases operative morbidity related to reduction in port size, already exists. Therefore, this study was performed to evaluate the safety and feasibility of the modified form of SILS using flexible endoscope in Cholecystectomy before clinical adoption. A 2 cm single periumbilical incision was performed, and flexible endoscope was introduced into the abdominal cavity. A laparoscopic grasper was inserted into the abdominal cavity for the traction of gall bladder. Cystic duct and artery were ligated by 5 mm Hem-o-lok$^{(R)}$. Then, gall bladder was dissected and resected from the liver with 5 mm Autonomy Laparo-Angle Maryland dissector and endoscopic needle knife. Resected gall bladder was wrapped by using specimen pouch and was retrieved through abdominal incision from the cavity. All three gall bladders were successfully removed. Hematological changes were not observed during examination periods. No leakage sign was identified at necropsy. The flexible endoscope, as distinct from conventional rigid laparoscope, allows the visualization from various angles and the wide range of motion, result in less crowding.

• Journal of Korea Water Resources Association
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• v.40 no.4
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• pp.325-334
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• 2007

In this study, a long-term unsteady simulation model has been developed using rigid water column theory which is more accurate than Extended-period model and more efficient comparing with water-hammer simulation model. The developed model is applied to 24-hours unsteady simulation considering daily water-demand and water-hammer analysis caused by closing a valve. For the case of 24-hours daily simulation, the pressure of each node decreases as the water demand increase, and when the water demand decrease, the pressure increases. During the simulation, the amplitudes of flow and pressure variation are different in each node and the pattern of flow variation as well as water demand is quite different than that of KYPIPE2. Such discrepancy necessitates the development of unsteady flow analysis model in water distribution network system. When the model is applied to water-hammer analysis, the pressure and flow variation occurred simultaneously through the entire network system by neglecting the compressibility of water. Although water-hammer model shows the lag of travel time due to fluid elasticity, in the aspect of pressure and flow fluctuation, the trend of overall variation and quantity of the result are similar to that of water-hammer model. This model is expected for the analysis of gradual long-term unsteady flow variations providing computational accuracy and efficiency as well as identifying pollutant dispersion, pressure control, leakage reduction corresponding to flow-demand pattern, and management of long-term pipeline net work systems related with flowrate and pressure variation in pipeline network systems