• Journal of Korean Neurosurgical Society
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• 제56권2호
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• pp.103-107
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• 2014

Objective : This study analyzed clinical and radiological outcomes of a zero-profile anchored spacer (Zero-P) and conventional cage-plate (CCP) for single level anterior cervical discectomy and fusion (ACDF) to compare the incidence and difference of postoperative dysphagia with both devices. Methods : We retrospectively reviewed our experiences of single level ACDF with the CCP and Zero-P. From January 2011 to December 2013, 48 patients who had single level herniated intervertebral disc were operated on using ACDF, with CCP in 27 patients and Zero-P in 21 patients. Patients who received more than double-level ACDF or combined circumferential fusion were excluded. Age, operation time, estimated blood loss (EBL), pre-operative modified Japanese Orthopaedic Association (mJOA) scores, post-operative mJOA scores, achieved mJOA scores and recovery rate of mJOA scores were assessed. Prevertebral soft tissue thickness and postoperative dysphagia were analyzed on the day of surgery, and 2 weeks and 6 months postoperatively. Results : The Zero-P group showed same or favorable clinical and radiological outcomes compared with the CCP group. Postoperative dysphagia was significantly low in the Zero-P group. Conclusions : Application of Zero-P may achieve favorable outcomes and reduce postoperative dysphagia in single level ACDF.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제21권5호
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• pp.1003-1008
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• 2017

The Internet of Things has attracted considerable research attention in recent years. In order for the new IoT technology to be widely used, the reliability and protection of information is required. IoT systems are very vulnerable to physical security due to their easy accessibility. Along with the development of SoC technology, many operating systems have been developed and many new operating systems have been introduced. In this paper, we describe the vulnerability analysis results for operating systems running on the ARMv7 Thumb Architecture hardware platform. For the recently introduced "Windows 10 IoT Core" operating system, I implemented the Zero-Day Attack by implanting the penetration code developed through the research into a specific IoT system. The virus detection test for the resulting penetration code was validated by referral to the "virustotal" site.

• International Journal of Highway Engineering
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• 제13권1호
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• pp.21-32
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• 2011

The frost penetration depth of pavement is usually estimated from the freezing index that made temperature data analysis of 30 years and decided the thickness of anti-frost layer. The field monitoring region in study was divided into five regions by freezing index 550~650$^{\circ}C{\cdot}$day, 450~550$^{\circ}C{\cdot}$day and 350~450$^{\circ}C{\cdot}$day. Each region has three-section of road pavement such as cutting area, boundary area of cutting and banking, and lower area of banking. The field monitoring system was established both in the section of anti-frost layer and in the section without anti-frost layer. The data analysis was conducted for determination of frost penetration depth within the paved road by the field monitoring system. The result showed that The temperature of subgrade without anti-frost layer shows below zero in centigrade for the region of freezing index 550~650$^{\circ}C{\cdot}$day, up and down around zero degree in subgrade for the region of freezing index 450~550$^{\circ}C{\cdot}$day, and there is no place existed below zero degree in subgrade for the region of freezing index below 450$^{\circ}C{\cdot}$day. With comparison of field frost penetration depth for the cross-sections of pavement, the cutting area shows the greatest frost penetration depth, and less influence of frost penetration depth for the boundary area of cutting and banking, and the least influenced for the lower area of banking.

• Management & Information Systems Review
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• 제26권
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• pp.293-309
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• 2008

This study examined the market efficiency of korea stock market by comparing variance ratios(VR) of stock groups which is sorted by market capitalization. We compute variance ratios of KOSPI large capitalization, midium capitalization, and small capitalization for 546 trading days from 2006/01/02 to 2008/04/15. For our study, we also use high frequency data that is; intra-day 1 minute data. The characteristics of variance ratios of stock groups by market capitalization as follows: From 1 to 5 minute interval, variance ratios of three stock group increase far from zero(0). The longer time interval, the more variance ratios decrease, but only large capitalization converge on around zero. This means that the market of large capitalization is more efficient compare to other stock groups. The entire sample period can be divided two sub-period because the impact of sub prime crisis arised from U.S.A. influences Korea stock market. Before sub prime crisis, the VRs of mid cap and small cap do not converge on around zero except large cap although the time interval is longer. After sub prime crisis, the VRs of three stock groups decrease when time interval is longer, but only large cap converge on around zero. We conclude that large cap is more efficient than other stock groups in Korea Stock Market.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.211-214
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• 2005

Bench-scale experiments conducted to evaluation of the biostimulation and bioaugmentation techniques in treatment of petroleum contaminated soil. The soil bioreactors were operated for a 52 day-period. PDB population in the stimulated treatments increased from $7{\times}10^4MPN/g$ soil in zero day to $7{\times}10^7MPN/g$ soil after 23 days. However, despite the initially higher PDB population in the augmented treatments, it was decreased PDB population with respect to time. The average biodegradation rate in the augmented treatments were greater than of the stimulated treatment in the early stage, but the average biodegradation rate in the latter stage were calculated $3{\sim}5mg/kg-day$ in the augmented treatments and 10.38mg/kg-day in the stimulated treatments. The TPH removal rate was calculated $20{\sim}30%$ in the augmented treatments and 53% in the stimulated treatments.

• Journal of Korean Society of Environmental Engineers
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• 제32권2호
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• pp.131-140
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• 2010

Zero waste clean city was visualized by designing the environmental fundamental facilities such as automated waste collection and bio-energizing system of domestic waste, which was categorized into food and combustible waste from urban area. The biomass circulation position was applied to the domestic waste collection position combined with bio-energizing system in the zero waste clean city. Bio-energizing system consisted of bio-gasification, bio-fuel and bioenergy-circulation process. Food wastes were treated by bio-gasification with anaerobic digestion, and combustible wastes were made of bio-fuel with pyrolysis/drying. Biogas and bio-fuel was utilized into the electric generation or boiler heat in bioenergy-circulation process. The emission of carbon dioxide(CO2) and construction fee of the environmental fundamental facilities related with domestic waste was estimated in the existing city and zero waste clean city, assuming the amount of food waste 35 ton/day, combustible waste 20 ton/day from domestic area. Consequently, 2.7 times lower carbon dioxide emission and 15% construction fee of the environmental fundamental facilities related with domestic waste were obtained from the zero waste clean city by comparing with existing city.

• Preventive Nutrition and Food Science
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• 제4권4호
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• pp.246-250
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• 1999

This study was conducted to develop the fermentation kinetic modeling for the prediction of pH and acidity changes in kimchi at isothermal and nonisothermal fermentation temperatures(0~15$^{\circ}C$) and salt concentrations(1.5~4.0%) using the traditional two-step method and alternative one-step method. The calculations of the two-step method of pH and acidity change during fermentation followed the pattern of the first order and zero order, respectively. The reaction rate constant of pH by the first order was increased from 0.008 {TEX}$day^{-1}${/TEX} to 0.017 {TEX}$day^{-1}${/TEX} by increasing the temperature from $0^{\circ}C$ to 15$^{\circ}C$ at 2.75% of salt concentration, and was decreased from 0.013 {TEX}$day^{-1}${/TEX} to 0.010 {TEX}$day^{-1}${/TEX} by increasing the salt concentration from 1.5% to 4.0% at 5$^{\circ}C$. For the pH and acidity of Kimchi, the zero order had a higher correlation than the first order to the estimate of the kinetics parameters by the one-step method. The {TEX}$E_{a}${/TEX} ranges of pH and acidity were 61.057~66.086 and 62.417~68.772 kJ/mole with different temperatures and salt concentrations. This one-step method had smaller and more realistic estimates of error(p〈0.05). The effective temperatures, {TEX}$T_{eff}${/TEX}, with 0~15$^{\circ}C$ of square function type of 12 hr intervals were 12.85, 11.48 and 12.46$^{\circ}C$ as increasing the salt concentration, 1.50, 2.75 and 4.00%, respectively. The {TEX}$T_{eff}${/TEX} were higher values than the mean temperature(7.5$^{\circ}C$).

• The Journal of the Korea institute of electronic communication sciences
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• 제7권2호
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• pp.279-285
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• 2012

Most national critical key infrastructure, such like electricity, nuclear power plant, and petroleum is run on SCADA (Supervisory Control And Data Acquisition) system as the closed network type. These systems have treated the open protocols like TCP/IP, and the commercial operating system, which due to gradually increasing dependence on IT(Information Technology) is a trend. Recently, concerns have been raised about the possibility of these facilities being attacked by cyber terrorists, hacking, or viruses. In this paper, the method to minimize threats and vulnerabilities is proposed, with the virtual honeynet system architecture and the attack detection algorithm, which can detect the unknown attack patterns of Zero-Day Attack are reviewed.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제23권5호
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• pp.939-946
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• 2013

This paper proposes normal behavior profiling methods for anomaly detection in IEC 61850 based substation network. Signature based security solutions, currently used primarily, are inadequate for APT attack using zero-day vulnerabilities. Recently, some researches about anomaly detection in control network are ongoing. However, there are no published result for IEC 61850 substation network. Our proposed methods includes 3-phase preprocessing for MMS/GOOSE packets and normal behavior profiling using one-class SVM algorithm. These approaches are beneficial to detect APT attacks on IEC 61850 substation network.

• Journal of the military operations research society of Korea
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• 제33권2호
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• pp.115-127
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• 2007

The army developed the ATCIS(Army Tactical Command Information System) for the battlefield information system with share the command control information through the realtime. The using the public key and the encryption equipment in the ATCIS is enough to the confidentiality, integrity. but, it is vulnerable about the availability with the zero day attack. In this paper, we implement the worm propagation simulation on the ATCIS infrastructure through the modelling on the ATCIS operation environment. We propose the countermeasures based on the results from the simulation.