• Journal of Communications and Networks
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• v.7 no.3
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• pp.367-376
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• 2005

The smooth handoff supported by the route optimization extension to the mobile IP standard protocol should support a packet buffering mechanism at the base station (BS), in order to reduce the degradation in TCP performance caused by packet losses within mobile network environments. The purpose of packet buffering at the BS is to recover the packets dropped during intersubnetwork handoff by forwarding the packets buffered at the previous BS to the new BS. However, when the mobile host moves to a congested BS within a new foreign subnetwork, the buffered packets forwarded by the previous BS are likely to be dropped. This subsequently causes global synchronization to occur, resulting in the degradation of the wireless link in the congested BS, due to the increased congestion caused by the forwarded burst packets. Thus, in this paper, we propose an implicit priority forwarding (IPF) packet buffering scheme as a solution to this problem within mobile IP based networks. In the proposed IPF method, the previous BS implicitly marks the priority packets being used for inter-subnetwork handoff. Moreover, the proposed modified random early detection (M-RED) buffer at the new congested BS guarantees some degree of reliability to the priority packets. The simulation results show that the proposed IPF packet buffering scheme increases the wireless link utilization and, thus, it enhances the TCP throughput performance in the context of various intersubnetwork handoff cases.

• Journal of KIISE:Databases
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• v.31 no.2
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• pp.163-173
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• 2004

Recently, location-based services are becoming very Popular in mobile environments. In this paper, we propose a new association based prefetch algorithm (called by STAP) that efficiently supports information service based on the large quantity of spatial database in mobile environments. We apply the spatial-temporal relations that are meaningful for location-based queries in mobile environments. Moreover, STAP considers user's mobility and the weight of spatial data. The relation of services is a new aspect not considered in previous cache politics. So STAP is the first prefetch algorithm considering the spatial-temporal relations and thus the cache policy begins to gain a new dimension. We evaluate the performance of STAP and prove the efficiency of STAP.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.52-55
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• 2002

Flow cytometric techniques were used to investigate cell size, protein content and cell cycle behavior of recombinant Saccharomyces cerevisiae strains producing human lysozyme (HLZ). Two different signal sequences, the native yeast $MF\alpha1$ signal sequence and the rat $\alpha-amylase$ signal sequence, were used for secretion of HLZ. The strain containing the rat $\alpha-amylase$ signal sequence showed a higher level of internal lysozyme and lower specific growth rates. Flow cytometric analysis of the total protein content and cell size showed the strain harboring the native yeast signal sequence had a higher total protein content than the strain containing the rat $\alpha-amylase$ signal sequence. Cell cycle analysis indicated that the two lysozyme producing recombinant strains had an increased number of cells in the $G_2+M$ phase of the yeast cell cycle compared with the host strain SEY2102.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2466-2472
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• 2013

Human immunodeficiency virus type-1 (HIV-1) is a causative agent of Acquired immunodeficiency syndrome (AIDS), which has affected a large population of the world. Viral envelope glycoprotein (gp120) is an intrinsic protein for HIV-1 to enter into human host cells. Molecular docking guided molecular dynamics (MD) simulation was performed to explore the interaction mechanism of heterobiaryl derivative with gp120. MD simulation result of inhibitor-gp120 complex demonstrated stability. Our MD simulation results are consistent with most of the previous mutational and modeling studies. Inhibitor has an interaction with the CD4 binding region. Van der Waals interaction between inhibitor and Val255, Thr257, Asn425, Met426 and Trp427 were important. This preliminary MD model could be useful in exploiting heterobiaryl-gp120 interaction in greater detail, and will likely to shed lights for further utilization in the development of more potent inhibitors.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.573-583
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• 2016

The review article presents some of the history of how paleoparasitology started in Brazil, making highlight the great responsible Dr. Luiz Fernando Ferreira and Dr. Adauto Araujo, the trajectory of paleoparasitology in Brazil since 1978 and its performance in science to the present day. In sequence, it is made a presentation of parasitological findings on human remains found in archaeological sites in South America, highlighting Brazil, Argentina, Chile, and Peru, where major discoveries have occurred. Many of the parasites found in archaeological material and mentioned in this review went out of Africa with the peopling of Europe and from there they dispersed around the world, where climatic conditions allow the transmission. However, humans have acquired other parasites of animals, since humans invaded new habitats or creating new habits adopting new technologies, thus expanding its range of influence on the environment. Thus, this review article is finalized with information that explain the importance of these findings in the interaction between parasites, human host, and ambient.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.5
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• pp.69-78
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• 2004

The change of attack techniques paradigm was begun by fast extension of the latest Internet and new attack form appearing. But, Most intrusion detection systems detect only known attack type as IDS is doing based on misuse detection, and active correspondence is difficult in new attack. Therefore, to heighten detection rate for new attack pattern, the experiments to apply various techniques of anomaly detection are appearing. In this paper, we propose an behavior profiling method using Bayesian framework based on graphics from audit data and visualize behavior profile to detect/analyze anomaly behavior. We achieve simulation to translate host/network audit data into BF-XML which is behavior profile of semi-structured data type for anomaly detection and to visualize BF-XML as SVG.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.7
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• pp.271-278
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• 2021

As the current cyber attacks become more intelligent, the existing Intrusion Detection System is difficult for detecting intelligent attacks that deviate from the existing stored patterns. In an attempt to solve this, a model of a deep learning-based intrusion detection system that analyzes the pattern of intelligent attacks through data learning has emerged. Intrusion detection systems are divided into host-based and network-based depending on the installation location. Unlike network-based intrusion detection systems, host-based intrusion detection systems have the disadvantage of having to observe the inside and outside of the system as a whole. However, it has the advantage of being able to detect intrusions that cannot be detected by a network-based intrusion detection system. Therefore, in this study, we conducted a study on a host-based intrusion detection system. In order to evaluate and improve the performance of the host-based intrusion detection system model, we used the host-based Leipzig Intrusion Detection-Data Set (LID-DS) published in 2018. In the performance evaluation of the model using that data set, in order to confirm the similarity of each data and reconstructed to identify whether it is normal data or abnormal data, 1D vector data is converted to 3D image data. Also, the deep learning model has the drawback of having to re-learn every time a new cyber attack method is seen. In other words, it is not efficient because it takes a long time to learn a large amount of data. To solve this problem, this paper proposes the Siamese Convolutional Neural Network (Siamese-CNN) to use the Few-Shot Learning method that shows excellent performance by learning the little amount of data. Siamese-CNN determines whether the attacks are of the same type by the similarity score of each sample of cyber attacks converted into images. The accuracy was calculated using Few-Shot Learning technique, and the performance of Vanilla Convolutional Neural Network (Vanilla-CNN) and Siamese-CNN was compared to confirm the performance of Siamese-CNN. As a result of measuring Accuracy, Precision, Recall and F1-Score index, it was confirmed that the recall of the Siamese-CNN model proposed in this study was increased by about 6% from the Vanilla-CNN model.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.33.3-33.3
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• 2019

Automatic, yet reliable methods to find and classify barred galaxies are going to be more important in the era of large galaxy surveys. Here, we introduce a new approach to classify barred galaxies by analyzing the butterfly pattern that Buta & Block (2001) reported as a bar signature on the potential map. We make it easy to find the pattern by moving the ratio map from a Cartesian coordinate to a polar coordinate. Our volume-limited sample consists of 1698 spiral galaxies brighter than Mr = -15.2 with z < 0.01 from the Sloan Digital Sky Survey/DR7 visually classified by Ann et al. (2015). We compared the results of the classification obtained by four different methods: visual inspection, ellipse fitting, Fourier analysis, and our new method. We obtain, for the same sample, different bar fractions of 63%, 48%, 36%, and 56% by visual inspection, ellipse fitting, Fourier analysis, and our new approach, respectively. Although automatic classifications detect visually determined, strongly barred galaxies with the concordance of 74% to 86%, automatically selected barred galaxies contain different amount of weak bars. We find a different dependence of bar fraction on the Hubble type for strong and weak bars: SBs are preponderant in early-type spirals, whereas SABs are in late-type spirals. Moreover, the ellipse fitting method often misses strongly barred galaxies in the bulge-dominated galaxies. These explain why previous works showed the contradictory dependence of the bar fraction on the host galaxy properties. Our new method has the highest agreement with visual inspection in terms of the individual classification and the overall bar fraction. In addition, we find another signature on the ratio map to classify barred galaxies into new two classes that are probably related to the age of the bar.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.1
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• pp.15-24
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• 2001

The purpose of this study is to evaluate the tissue response in applying of various bone substitutes included toothash-plaster mixture, resorbable hydroxylapatite (HA) and demineralized freeze-dried bone and to show the clinical usefulness of toothash-plaster mixture for the repair of craniomaxillofacial bone defect. For this experiment, 100 Sprague-Dawley rats weighing 200gm or more were used. There were four experimental groups: group I, toothash-plaster mixture; group II, demineralized freeze-dried bone; group III, resorbable HA; and group IV, control group. A full thickness, round bone defect measuring 10mm in diameter was created in the midcranium, and the substitutes cited above were embedded in the experimental rats based on their group assignment. Blood clot was filled in the rats assigned to the control group. Experimental rats were sacrificed on the 1st, 3rd, 5th, 8th, 12th and 24th week after implantation and stained with the hematoxylineosin, Masson's Trichrome, using Van Gieson's stain method, and were examined under light microscope. The results were as follows: 1. In all the groups, prominent inflammatory reaction and the infiltration of multinucleated giant cells were noted during the early stage. Gradual healing decreased this reaction. 2. Among the rats in the experimental group II, which were given demineralized freeze-dried bone implants, active formation of new bone traveculae manifested. Chondroid tissues appeared, and it was suggested that the defect was filled with newly formed bone by virtue of osteoinductive activity. On the 12th week after the experiments, most of the defect was filled with newly formed bone trabeculae. 3. In experimental groups I and III, it was noted that HA manifested a healing process similar to that characterized by the toothash-plaster mixture, but inflammatory reaction was more prominent in experimental group I. Active osteoblasts were observed along the periphery of osteoid tissues, while newly formed bone trabeculae appeared adjacent to the implanted materials three weeks later. Formation increased to the extent that newly formed bone trabeculae fused directly with the host bone. Increase in new bone ingrowth into the filling materials was revealed by both experimental groups. 4. In the control group, new bone formation adjacent to the host bone was observed, but most of the defect was filled with mature connective tissue 24 weeks after the experiments.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.933-938
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• 2006

Decaprenyl diphosphate synthase (DPS) is the key enzyme for the production of coenzyme $Q_{10}$ ($CoQ_{10}$). A dps gene from Sinorhizobium meliioti KCCM 11232 (IFO 14782) was isolated by PCR and then cloned in Escherichia coli. DNA sequencing analysis revealed an open reading frame of 1,017 bp encoding a 338-amino-acid protein. The protein was identical at the 98% level to the putative octaprenyl diphosphate synthase (IspB) of S. meliloti 1021. The deduced amino acid sequence included the DDxxD domains conserved in the majority of the prenyl diphosphate synthases. Heterologous expression in E. coli BL21 (DE3) was carried out, and the $CoQ_{10}$ produced was then analyzed by HPLC. E. coli BL21 (DE3) harboring the dps gene from S. melioti produced CoQ$_{10}$ in addition to endogenous coenzyme Q$_8$ (CoQ$_8$), whereas wild-type E. coli BL21 (DE3) host did not have the ability of producing CoQ$_{10}$. The results suggest that the putative dps from S. meliloti KCTC 2353 encoded the DPS.