• Convergence Security Journal
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• v.7 no.1
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• pp.63-75
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• 2007

Most of computer systems to be connected to network have been exposed to some network attacks and became to targets of system attack. System managers have established the IDS to prevent the system attacks over network. The previous IDS have decided intrusions detecting the requested connection packets more than critical values in order to detect attacks. This techniques have False Positive possibilities and have difficulties to detect the slow scan increasing the time between sending scan probes and the coordinated scan originating from multiple hosts. We propose the port scan detection rules detecting the RST/ACK flag packets to request some abnormal connections and design the data structures capturing some of packets. This proposed system is decreased a False Positive possibility and can detect the slow scan, because a few data can be maintained for long times. This system can also detect the coordinated scan effectively detecting the RST/ACK flag packets to be occurred the target system.

• BMB Reports
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• v.39 no.2
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• pp.167-170
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• 2006

Bovine adenosine deaminase undergoes a nondenaturational conformational change at $29^{\circ}C$ upon heating which is characterized by a large increase in heat capacity. We have determined the transition state thermodynamics of the conformational change using a novel application of differential scanning calorimetry (DSC) which employs very slow scan rates. DSC scans at the conventional, and arbitrary, scan rate of $1^{\circ}C/min$ show no evidence of the transition. Scan rates from 0.030 to $0.20^{\circ}C/min$ reveal the transition indicating it is under kinetic control. The transition temperature $T_t$ and the transition temperature interval ${\Delta}T$ increase with scan rate. A first order rate constant $k_1$ is calculated at each $T_t$ from $k_1\;=\;r_{scan}/{\Delta}T$, where $r_{scan}$ is the scan rate, and an Arrhenius plot is constructed. Standard transition state analysis reveals an activation free energy ${\Delta}G^{\neq}$ of 88.1 kJ/mole and suggests that the conformational change has an unfolding quality that appears to be on the direct path to the physiological-temperature conformer.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.5
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• pp.679-684
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• 2008

The slow port scan attack detection is the one of the important topics in the network security. We suggest an abnormal traffic control framework to detect slow port scan attacks using fuzzy rules. The abnormal traffic control framework acts as an intrusion prevention system to suspicious network traffic. It manages traffic with a stepwise policy: first decreasing network bandwidth and then discarding traffic. In this paper, we show that our abnormal traffic control framework effectively detects slow port scan attacks traffic using fuzzy rules and a stepwise policy.

• Journal of Electrochemical Science and Technology
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• v.13 no.3
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• pp.347-353
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• 2022

Agarose hydrogel, a solid electrolyte, was investigated voltammetrically in terms of transport properties and natural convection effects using a ferrocenyl compound as a redox probe. To confirm the diffusion properties of solute on the agarose interface, the diffusion coefficients (D) of ferrocenemethanol in agarose hydrogel were determined by cyclic voltammetry (CV) according to the concentration of agarose hydrogel. While the value of D on the agarose interface is smaller than that in the bulk solution, the square root of the scan rate-dependent peak current reveals that the mass transport behavior of the solute on the agarose surface shows negligible convection or migration effects. In order to confirm the reduced natural convection on the gel interface, scan rate-dependent CV was performed in the solution phase and on the agarose surface, respectively. Slow scan voltammetry at the gel interface can determine a conventional and reproducible diffusion-controlled current down to a scan rate of 0.3 mV/s without any complicated equipment.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.55-63
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• 2004

Purpose : To evaluate the reflection of tumor motion according to the planning CT scan time. Material and Methods : A model of N-shape, which moved aiong the longitudinal axis during the ventilation caused by a mechanical ventilator, was produced. The model was scanned by planning CT, while setting the relative CT scan time (T: CT scan time/ventilatory period) to 0.33, 0.50, 0.67, 0.75, 1.00, 1.337, and 1.537. In addition, three patients with non-small cell lung cancer who received stereotactic radiosurgery In the Department of Radiation Oncology, Asan Medical Center from 03/19/2002 to 05/21/2002 were scanned. Slow (10 Premier, Picker, scan time 2.0 seconds per slice) and fast CT scans (Lightspeed, GE Medical Systems, with a scan time of 0.8 second per slice) were peformed for each patient. The magnitude of reflected movement of the N-shaped model was evaluated by measuring the transverse length, which reflected the movement of the declined bar of the model at each slice. For patients' scans, all CT data sets were registered using a stereotactic body frame scale with the gross tumor volumes delineated in one CT image set. The volume and three-dimensional diameter of the gross tumor volume were measured and analyzed between the slow and fast CT scans. Results : The reflection degree of longitudinal movement of the model increased in proportion to the relative CT scan times below 1.00 7, but remained constant above 1.00 T Assuming the mean value of scanned transverse lengths with CT scan time 1.00 T to be $100\%$, CT scans with scan times of 0.33, 0.50, 0.57, and 0.75 T missed the tumor motion by 30, 27, 20, and $7.0\%$ respectively, Slow (scan time 2.0 sec) and Fast (scan time 0.8 sec) CT scans of three patients with longitudinal movement of 3, 5, and 10 mm measured by fluoroscopy revealed the increases in the diameter along the longitudinal axis Increased by 6.3, 17, and $23\%$ in the slow CT scans. Conculsion : As the relative CT scan time increased, the reflection of the respiratory tumor movement on planning CT also Increased, but remained constant with relative CT scan times above 1.00 T When setting the planning CT scan time above one respiration period (>1.00 T), only the set-up margin is needed to delineate the planning target volume. Therefore, therapeutic ratio can be increased by reducing the radiation dose delivered to normal lung tissue.

• The KIPS Transactions:PartC
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• v.8C no.5
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• pp.543-550
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• 2001

In this paper, an improved detection system for the network vulnerability scan attacks is proposed. The proposed system improves the methodology for detecting the network vulnerability scan attacks and provides a global detection and response capability that can counter attacks occurring across an entire network enterprize. Through the simulation, we show that the proposed system can detect vulnerable port attacks, coordinated attacks, slow scans and slow coordinated attacks. We also show our system can achieve more global and hierarchical response to attacks through the correlation between server and agents than a stand-alone system can make.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.116-120
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• 2008

Prostate cancer is the second leading cause of cancer death of men in western countries and the death related to this disease in Korea is also getting increased. Although anatomic imaging tools such as transrectal US or MRI have been playing a great role in detection of primary prostate lesion, the evaluation of regional lymph node or distant organ metastasis using these modalities is not successful. $^{18}F-FDG-PET$ scan is emerging diagnostic tool for various malignancies. Considering the usual characteristics of prostate cancer such as slow growing and osteoblastic metastasis, the application of FDG PET scan to this disease might be limited. However, in advanced prostate cancer refractory to chemotherapy, FDG PET scan show strong FDG uptake and SUV changes in serial PET scan can be a good indicator of treatment response. Although FDG PET can be useful only in limited cases of prostate cancer, its indication can be widened in future owing to rapid technical improvement and accumulated experiences in this field.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.219-225
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• 2014

The New efficient Mux-based scan latch cell design and scan test of LOS/LOC modes are proposed for detection of delay faults in digital logic circuits. The proposed scan cell design can support LOS(Launch-off-Shift) and LOC(Launch-off-Capture) tests with high fault coverage and low scan power and it can alleviate the problem of the slow selector enable signal and hold signal by supporting the logic capable of switching at the operational clock speeds. Also, it efficiently controls the power dissipation of the scan cell design during scan testing. Functional operation and timing simulation waveform for proposed scan hold cell design shows improvement in at-speed test timing in both test modes.

• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.91-102
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• 2012

Network port scan attack is the method for finding ports opening in a local network. Most existing IDSs(intrusion detection system) record the number of packets sent to a system per unit time. If port scan count from a source IP address is higher than certain threshold, it is regarded as a port scan attack. The degree of risk about source IP address performing network port scan attack depends on attack count recorded by IDS. However, the measurement of risk based on the attack count may reduce port scan detection rates due to the increased false negative for slow port scan. This paper proposes a method of summarizing 4 types of information to differentiate network port scan attack more precisely and comprehensively. To integrate the riskiness, we present a risk index that quantifies the risk of port scan attack by using PCA. The proposed detection method using risk index shows superior performance than Snort for the detection of network port scan.

• BMB Reports
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• v.40 no.2
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• pp.205-211
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• 2007

The stability curve - a plot of the Gibbs free energy of unfolding versus temperature - is calculated for bovine erythrocyte carbonic anhydrase in 150 mM sodium phosphate (pH = 7.0) from a combination of reversible differential scanning calorimetry measurements and isothermal guanidine hydrochloride titrations. The enzyme possesses two stable folded conformers with the conformational transition occurring at ~30$^{\circ}C$. The methodology yields a stability curve for the complete unfolding of the enzyme below this temperature but only the partial unfolding, to the molten globule state, above it. The transition state thermodynamics for the low- to physiological-temperature conformational change are calculated from slow-scan-rate differential scanning calorimetry measurements where it is found that the free energy barrier for the conversion is 90 kJ/mole and the transition state possesses a substantial unfolding quality. The data therefore suggest that the x-ray structure may differ considerably from the physiological structure and that the two conformers are not readily interconverted.