• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.185-192
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• 2006

By mistaking normal packets for harmful traffic, it may not offer service according to the intention of attacker with harmful traffic, because it is not easy to classify network traffic for normal service and it for DUoS(Distributed DoS) attack like the Internet worm. And in the IPv6 environment these researches on harmful traffic are weak. In this dissertation, hosts in the IPv6 environment are attacked by NETWIB and their attack traffic is monitored, then the statistical information of the traffic is obtained from MIB(Management Information Base) objects used in the IPv6. By adapting the ESM(Exponential Smoothing Method) to this information, a normal traffic boundary, i.e., a threshold is determined. Input traffic over the threshold is thought of as attack traffic.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.356-363
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• 2004

In this research, the shear behavior of four different interfaces consisting of 4 types of geosynthetics was examined, and both static and dynamic tests for the geosynthetic interface were conducted. The monotonic shear experiments were performed by using an inclined board apparatus and large direct shear device. The interface shear strength obtained from the inclined board tests were compared with those calculated from large direct shear tests. The comparison results indicated that direct shear tests are likely to overestimate the shear strength in low normal stress range where direct shear tests were not performed. Curved failure envelopes were also obtained for interface cases where two static shear tests were conducted. By comparing the friction angles measured from three tests, i.e. direct shear, inclined board, and shaking table tests, it was found that the friction angle might be different depending on the test method and normal stresses applied in this research. Therefore, it was concluded that the testing method should be determined carefully by considering the type of loads and the normal stress expected in the field.

• Journal of Oriental Neuropsychiatry
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• v.9 no.1
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• pp.59-71
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• 1998

The effect of Samyonjihwangtang(SJT) on th level of brain antioxidants was examined in aged rat. Samyongjihwangtang(SJT) is assed Cervi Pantiri-chum Cornu, Ginseng Radix to Yukmijihwangtang. The experimental groups were divided into three groups and treated as follows ; normal group(NC), Vt.E administrated group(PC), SJT administrated Group(SJT). From the purified microsome of brain tissue, those were measures the amounts of oxidant materials like malonaldehyde(MDA) and H_2O_2, then activities of antioxidants enxymes like Superoxide dismutase, Catalase, NADPH-cytochrome P-450 reductase.The results were as follows;1. In TBA reaction to measure the amount of MDA, oxidant material of brain tissue of aged rat, both treated groups showed significant decrease.2. In the formation of Hydrogen peroxide, the treated group(SJT) showed a little decrease.3. The activity of Superoxide dismutase was increased significantly in both treated groups than normal group.4. the activity of Catalase was increased significantly in both treated groups than normal group. 5. The activity of NADPH-cytochrome P-450 reductase in the treated group(SJT) showed a little increase.According to the above results, it is suggested that Samyongjihwangtag(SJT) has some antioxidant effects on the tissue of brain.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.42-44
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• 2006

Up to the present, finger replantation patients have complained about various symptoms because of blood circulatory failure. Objective evaluation methods for the level of the blood circulatory failures in fingers were needed other than patient's subjective symptoms and complaints. Photoplethysmogram(PPG) measured from fingers is very useful for evaluation of vascular aging and sclerosis level since the PPG signal represents characteristics of peripheral vascular. Several researchers have reported that second derivative of the finger PPG waveform was useful to evaluate vascular compliance and developed various analysis methods for vascular compliance. However, vascular compliance study for finger replantation patient was never evaluated by using second derivative of PPG. Therefore, we aimed to objectively compare and to assess normal and replanted finger vascular compliance using the second derivative of PPG waveform in this study. The evaluated factors of second derivative of PPG are 'a', 'b', 'c', 'd', 'e' and b/a represents vascular compliance. Study found out that when vascular compliance is decreased, b/a is increased, the absolute value of b/a is decreased. For 43 finger replantation patients, the average vascular compliance of replanted finger is lower than the normal finger statistically(p=0.001). we suggested an objective evaluation of finger vascular compliance for finger replantation patients and effect of surgical operation.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.67-69
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• 2007

Recently, the prevalence rate of diabetes in Korea has been increasing rapidly due to high growth of economy and changes in dietary lifestyle. Vascular complication is one of diabetic complications which have frequently occurred by obesity, hyperglycemia and impaired glucose metabolism. Photoplethysmogram(PPG) measured from finger and toe is very useful for evaluation of vascular aging and sclerosis level since the PPG signal represents characteristics of peripheral vascular. Several researchers have reported that second derivative of the finger PPG waveform was useful to evaluate vascular compliance and developed various analysis methods for vascular compliance. However, peripheral vascular compliance study for diabetic patient was never evaluated by using second derivative of PPG. Therefore, we aimed to objectively compare and to assess normal and diabetic group vascular compliance using the second derivative of PPG waveform in this study. The evaluated factors of second derivative of PPG are 'a', 'b', 'c', 'd', 'e' and b/a represents vascular compliance. Study found out that when vascular compliance is decreased, b/a is increased, the absolute value of b/a is decreased. The average vascular compliance of 50 diabetic patients with neuropathy is statistically lower than the normal group(p<0.05). We suggest an objective evaluation of peripheral vascular compliance for diabetic patients and prevention of vascular complication.

• The korean journal of orthodontics
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• v.20 no.2
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• pp.227-245
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• 1990

The purpose of this study was to analyze the reorganization of periodontal ligament after collagenase treatment with autoradiography. The author compared the collagenase-treated experimental group and no-treated experimental group with control group. Fourty eight Sprague-Dawley rats were divided into nine groups, including normal control and immediate group. Closed coil springs were used between the upper incisors and the first molars with 100 grams. Collagenase and $^3H-proline$ were adminstered and the samples were sacrificed and sectioned. After being dipped into the NTB-3 emulsion the samples were analyzed with light microscope under H/E stain. Data were analyzed by t-test and ANOVA. The results were as follows: 1) Generally collagenase-treated groups got more $^3H-proline$ uptake than no-treated groups. 2) Compared with normal control group, collagenase-treated group had the same $^3H-proline$ uptake in amount at 21th day. 3) Among cemento-enamel junction, middle, apex areas, cementa-enamel junction area of collagenase-treated group arrived at normal control level earlier than no-treated group. 4) Cemento-enamel junction area had the most $^3H-proline$ incorporation amount in no-treated group, but apex area had the most in collagenase group.

• Journal of the Korean Statistical Society
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• v.7 no.1
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• pp.3-10
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• 1978

Let $X_i,...,X_n$ be a random sample from a distribution with cumulants $K_1, K_2,...$. The statistic $t = \frac{\sqrt{x}(\bar{X}-K_1)}{S}$ has the well-known 'student' distribution with $\nu = n-1$ degrees of freedom if the $X_i$ are normally distributed (i.e., $K_i = 0$ for $i \geq 3$). An Edgeworth series expansion for the distribution of t when the $X_i$ are not normally distributed is obtained. The form of this expansion is Prob $(t

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.310-310
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• 2011

Morphological evolution of amorphous carbon film is investigated by molecular dynamics simulation. Here, energetic carbon atoms (75 eV) are deposited on the diamond (001) substrate to find effect of incidence angles. At normal and near-normal incidences ($0^{\circ}{\sim}30^{\circ}$) atomically smooth surfaces are observed during their growth. However, rough surfaces emerge and develop into a ripple structure at grazing incidences ($60^{\circ}{\sim}70^{\circ}$). The different growth modes according to the incidence angles can be described by impact-induced displacements of atoms. Downhill transport along any sloped surfaces is predominant for the case of normal incidence. As the incidence angles become grazing, uphill transport is allowed along the surfaces, which have smaller slopes than incidence angle, so the surface features can be amplified. Impact-induced transport and self-shadowing effect can be responsible to the initial growth of seeding structures at a grazing incidence, which would be grown up as tilted columnar structures in further depositions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.12
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• pp.5464-5484
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• 2016

Few samples face recognition has become a highly challenging task due to the limitation of available labeled samples. As two popular paradigms in face image representation, sparse component analysis is highly robust while parts-based paradigm is particularly flexible. In this paper, we propose a probabilistic generative model to incorporate the strengths of the two paradigms for face representation. This model finds a common spatial partition for given images and simultaneously learns a sparse component analysis model for each part of the partition. The two procedures are built into a probabilistic generative model. Then we derive the score function (i.e. feature mapping) from the generative score space. A similarity measure is defined over the derived score function for few samples face recognition. This model is driven by data and specifically good at representing face images. The derived generative score function and similarity measure encode information hidden in the data distribution. To validate the effectiveness of the proposed method, we perform few samples face recognition on two face datasets. The results show its advantages.

• Phonetics and Speech Sciences
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• v.10 no.2
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• pp.69-76
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• 2018

The elderly are at increased risk of developing dysphagia due to aging and illnesses. The aim of the current study was to analyze, via an acoustic study, the change in the voice quality of normal elderly people after a 3oz water-swallow test. Subjects included a group of 60 normal elderly people (age: $mean{\pm}SD=76.9{\pm}6.66$) and 60 healthy young adults (age: $mean{\pm}SD=25.1{\pm}2.36$). Every participant produced a five-second /a/ phonation pre- and post-swallowing, and the fractioned two-second sections were analyzed using the MDVP (multi dimensional voice program) analysis. The elderly group demonstrated a post-swallowing increase in the following related acoustic parameters: fundamental frequency, fundamental frequency variation, amplitude-variation, and noise in both two-second sections. However, the younger group showed an increase only in frequency related acoustic parameters (i.e., STD ) in the first two-second section. The significant changes in values in the post-swallowing parameters might indicate temporary irregularities in pitch and amplitude along with higher amounts of noise in the voice. The results could be attributed to water residues in the vocal fold and vocal tract, as well as a deterioration of the motor and sensory functions caused by anatomical and physiological changes that result from aging.