• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.453-462
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• 2009

Studies on software plagiarism detection, prevention and judgement have become widespread due to the growing of interest and importance for the protection and authentication of software intellectual property. Many previous studies focused on comparing all pairs of submitted codes by using attribute counting, token pattern, program parse tree, and similarity measuring algorithm. It is important to provide a clear-cut model for distinguishing plagiarism and collaboration. This paper proposes a source code clustering algorithm using a probability model on extreme value distribution. First, we propose an asymmetric distance measure pdist($P_a$, $P_b$) to measure the similarity of $P_a$ and $P_b$ Then, we construct the Plagiarism Direction Graph (PDG) for a given program set using pdist($P_a$, $P_b$) as edge weights. And, we transform the PDG into a Gumbel Distance Graph (GDG) model, since we found that the pdist($P_a$, $P_b$) score distribution is similar to a well-known Gumbel distribution. Second, we newly define pseudo-plagiarism which is a sort of virtual plagiarism forced by a very strong functional requirement in the specification. We conducted experiments with 18 groups of programs (more than 700 source codes) collected from the ICPC (International Collegiate Programming Contest) and KOI (Korean Olympiad for Informatics) programming contests. The experiments showed that most plagiarized codes could be detected with high sensitivity and that our algorithm successfully separated real plagiarism from pseudo plagiarism.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.1
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• pp.80-91
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• 2010

As the volume of image data increases dramatically, its good organization of image data is crucial for efficient image retrieval. Clustering is a typical way of organizing image data. However, traditional clustering methods have a difficulty of requiring a user to provide the number of clusters as a parameter before clustering. In this paper, we discuss an approach for clustering image data that does not require the parameter. Basically, the proposed approach is based on Cross-Association that finds a structure or patterns hidden in data using the relationship between individual objects. In order to apply Cross-Association to clustering of image data, we convert the image data into a graph first. Then, we perform Cross-Association on the graph thus obtained and interpret the results in the clustering perspective. We also propose the method of hierarchical clustering and the method of outlier detection based on Cross-Association. By performing a series of experiments, we verify the effectiveness of the proposed approach. Finally, we discuss the finding of a good value of k used in k-nearest neighbor search and also compare the clustering results with symmetric and asymmetric ways used in building a graph.

• The korean journal of orthodontics
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• v.36 no.3 s.116
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• pp.218-227
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• 2006

Although the submentovertex radiograph and surface EMG are not often used due to the difficulty of interpretation, they are accepted as useful diagnostic and analytic aids for skeletal asymmetry. There have been reports which state that they were also useful for the evaluation of vertical skeletal relations. The purpose of this study was to evaluate the correlations between EMG data, measurements from submentovertex radiographs, facial types and facial asymmetry following examination of 60 asymmetric patients. The radiographic corpus length were greater in the nonaffected sides (p<0.001), gonion to interspinosum axis were greater in the affected sides and the mandibular condyle and gonion were located more anteriorly in the non-affected sides than in the affected sides but not significant (p=0.07). The activity of the anterior temporal muscle in rest position was higher in the affected sides than in the non-affected sides (p<0.01). The activity of the masseter muscle at maximum clenching was found to be nonsignificant but it was higher in the affected sides than in the non-affected sides (p=0.09). There was positive correlation between facial index and the intercondylar axes angle (p<0.01). There was positive correlation between masseter muscle activity in maximum occlusion and facial index in the affected and non-affected sides (p<0.05). The results demonstrate that the submentovertex radiograph and EMG can provide useful information for the evaluation of horizontal and vertical skeletal relations.

• Journal of the Korean Vacuum Society
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• v.17 no.1
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• pp.51-57
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• 2008

we have demonstrated structural evolution and optical properties of Si-nanowires (NWs) synthesized on Si (111) substrates with nanoscale Au-Si islands by rapid thermal chemical vapor deposition (RTCVD). The Au-Si nano-islands (10-50nm in diameter) were employed as a liquid-droplet catalysis to grow Si-NWs via vapor-liquid-solid mechanism. The Si-NWs were grown by a mixture gas of SiH4 and H2 at a pressure of 1.0 Torr and temperatures of $500{\sim}600^{\circ}C$. Scanning electron microscopy measurements showed that the Si-NWs are uniformly sized and vertically well-aligned along <111> direction on Si (111) surfaces. The resulting NWs are ${\sim}60nm$ in average diameter and ${\sim}5um$ in average length. High resolution transmission microscopy measurements indicated that the NWs are single crystals covered with amorphous SiOx layers of ${\sim}3nm$ thickness. In addition, the optical properties of the NWs were investigated by micro-Raman spectroscopy. The downshift and asymmetric broadening of the Si main optical phonon peak were observed in Raman spectra of Si-NWs, which indicates a minute stress effects on Raman spectra due to a slight lattice distortion led by lattice expansion of Si-NW structures.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.279-285
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• 2007

We have demonstrated structural evolution and optical properties of the Si-NWs on Si (111) substrates with synthesized nanoscale Au-Si islands by rapid thermal chemical vapor deposition(RTCVD). Au nano-islands (10-50nm in diameter) were employed as a liquid-droplet catalysis to grow Si-NWs via vapor-liquid-solid mechanism. Si-NWs were grown by a mixture gas of $SiH_4\;and\;H_2$ at pressures of $0.1{\sim}1.0$Torr and temperatures of $450{\sim}650^{\circ}C$. SEM measurements showed the formation of Si-NWs well-aligned vertically for Si (111) surfaces. The resulting NWs are 30-100nm in diameter and $0.4{\sim}12um$ in length depending on growth conditions. HR-TEM measurements indicated that Si-NWs are single crystals convered with about 3nm thick layers of amorphous oxide. In addition, optical properties of NWs were investigated by micro-Raman spectroscopy. The downshift and asymmetric broadening of the Si optical phonon peak with a shoulder at $480cm^{-1}$ were observed in Raman spectra of Si-NWs.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.755-766
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• 2008

Recently, NAND flash memory is becoming into the spotlight as a next-generation storage device because of its small size, fast speed, low power consumption, and etc. compared to the hard disk. However, due to the distinct characteristics such as erase-before-write architecture, asymmetric operation speed and unit, disk-based systems and applications may result in severe performance degradation when directly implementing them on NAND flash memory. Especially when a B-tree is implemented on NAND flash memory, intensive overwrite operations may be caused by record inserting, deleting, and reorganizing. These may result in severe performance degradation. Although ${\mu}$-tree has been proposed in order to overcome this problem, it suffers from frequent node split and rapid increment of its height. In this paper, we propose Log-Structured B-Tree(LSB-Tree) where the corresponding log node to a leaf node is allocated for update operation and then the modified data in the log node is stored at only one write operation. LSB-tree reduces additional write operations by deferring the change of parent nodes. Also, it reduces the write operation by switching a log node to a new leaf node when inserting the data sequentially by the key order. Finally, we show that LSB-tree yields a better performance on NAND flash memory by comparing it to ${\mu}$-tree through various experiments.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.935-944
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• 2002

It is the Mobile Ad Hoc Networks that constituted with serveral mobile node that can communicate with other mobile nodes. Until now, there were no routing protocols considering such as Multimediadata, VOD (Video On Demand), which is required of lots of bandwidth in Mobile Ad Hoc Network, io we are in the need of QoS (Quality of Service)routing protocol to transmit the data packets faster and more accurate. Also, there are an unidirectional links due to asymmetric property of mobile terminals or current wireless environments on practical mobile ad hoc networks. However, at present, the existing mobile ad hoc routing protocols are implemented to support only bidirectional links. In this paper, we propose the Advanced Routing routing protocol in order to implement a new routing protocol, which is fit to mobile ad hoc networks containing unidirectional links and to support QoS service. For the performance evaluation, we use NS-2 simulator of U.C. Berkeley. We could get not only increased received data rate and decreased average route discovery time, but also network load decreases with compared Best effort service.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.6
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• pp.413-422
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• 2012

The purpose of this study is to investigated the mechanism of pharmacological action of local anesthetic and provide the basic information about the development of new effective local anesthetics. Fluorescent probe techniques were used to evaluate the effect of lidocaine HCl on the physical properties (transbilayer asymmetric lateral and rotational mobility, annular lipid fluidity and protein distribution) of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex, and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from the SPMV. An experimental procedure was used based on selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) and 1,6-diphenyl-1,3,5-hexatriene (DPH) by trinitrophenyl groups, and radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py. Lidocaine HCl increased the bulk lateral and rotational mobility of neuronal and model membrane lipid bilayes, and had a greater fluidizing effect on the inner monolayer than the outer monolayer. Lidocaine HCl increased annular lipid fluidity in SPMV lipid bilayers. It also caused membrane proteins to cluster. The most important finding of this study is that there is far greater increase in annular lipid fluidity than that in lateral and rotational mobilities by lidocaine HCl. Lidocaine HCl alters the stereo or dynamics of the proteins in the lipid bilayers by combining with lipids, especially with the annular lipids. In conclusion, the present data suggest that lidocaine, in addition to its direct interaction with proteins, concurrently interacts with membrane lipids, fluidizing the membrane, and thus inducing conformational changes of proteins known to be intimately associated with membrane lipid.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.439-448
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• 2018

With the aim of examining changes in plantar pressure while walking depending on the position of carrying a bag, this study measured the plantar pressure of 33 normal male and female adults using the F-scan System in four different positions to carry a bag: walking without carrying a bag; walking with carrying a bag on both shoulders; walking with carrying a bag on one shoulder; and walking with carrying a bag in one hand. Changes in the plantar pressure of the subjects obtained in this study and the asymmetry of the left and right feet were analyzed. The plantar pressure of the different areas of the feet in the four different positions to carry a bag was compared. The left foot, except its toes and metatarsus, showed a statistically significant difference among the five conditions, and the right foot, except its 4th and 5th caput metatarsalis, also showed a statistically significant difference (P>.05). Given the results of this study, this experiment to examine changes in plantar pressure does not seem to be enough to identify which position to carry a bag, except carrying a bag on both shoulders, would have the lowest negative impact on the feet. It will be necessary to conduct a follow-up study on changes in plantar pressure depending on the position of carrying a bag and methods that can effectively treat abnormal positions such as scoliosis and kyphosis using asymmetric loads.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.235-258
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• 2022

We interpreted the evolutionary history of the southwestern part of the Pohang Basin, the largest Miocene basin in the southeastern part of the Korean Peninsula, based on the detailed geological mapping and analysis of the geological structures. The southwestern part of the Pohang Basin can be divided into the Bomun Domain in the west and Ocheon Domain in the east by an NNE-trending horst-in-graben. These two domains have different geometries and deformation histories. The Bomun Domain was rarely deformed after the incipient extension of the basin, whereas the Ocheon Domain is an area where continued and overlapped deformations occurred after the basin fill deposition. Therefore, the Bomun Domain provides critical information on the initial extension mode of the Pohang Basin. The subsidence of the Bomun Domain was led by the zigzag-shaped western border fault that consists of NNE-striking normal and NNW-striking dextral strike-slip fault segments. This border fault is connected to the Yeonil Tectonic Line (YTL), a regional dextral principal displacement zone and the westernmost limit of Miocene crustal deformation in SE Korea. Therefore, it is interpreted that the Pohang Basin was initially extended in WNW-ESE direction as a transtensional fault-termination basin resulting from the movement of NNE-striking normal and/or oblique-slip faults formed as right-stepover in the northern termination of the YTL activated since approximately 17-16.5 Ma. As a result, an NNE-trending asymmetric graben or half-graben exhibiting an westward deepening of basin depth was formed in the Bomun Domain. Afterward, crustal extension and deformation were migrated to the east, including the Ocheon Domain.