• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.169-177
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• 2007

Existing wireless access (mobile) routers are based commonly on the network address and port translation (NAPT) technique which permits simultaneously sharing a subscriber's connection to the network with multiple users. However, the NAPT architecturally makes the users invisible on the network side, thus becoming a user-oriented connection technique. In this paper, we propose a novel service provider-oriented unlicensed nomadic access relay station (WiNNERS) for helping wireless broadband network service providers to make their business more lucrative by accommdating unlicensed band users as subscribers into their network. The WiNNERS offers service providers the capability to directly manage each of the unlicensed band users at the network side. This direct management allows the service providers to flexibly and simply handle QoS, access control, and billing for each user. In order to distinguish each of the unlicensed band users the WiNNERS constructs a virtual tunnel from each user's terminal to the network access router using connection identifiers which is defined for service flow management within the WiBro system, Consequently, our proposed service provider-oriented relay station can be included into the WiBro network system with minimum modifications.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.407-412
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• 2015

This study investigated flexural properties of indirect Gum-shade composite resins for esthetic improvement. The material utilized in this study was Crea.lign, Twiny flow and Twiny paste (TP). Ten specimens were fabricated with a dimension of $25{\times}2{\times}2mm$ according to the ISO 4049. After fabrications, specimens were stored in the distilled water for 24 hours at the temperature of $37^{\circ}C$. Three-point bending test was performed in universal testing machine (Instron 3344; Instron, USA) at a crosshead speed of 1 mm/min until the failure occurred. TP exhibited a higher flexural strength (FS) and flexural modulus (FM) compared to the flowable materials. There were significant differences among the three materials in FS and FM. However, there was no significant difference in work of fracture (WOF) in all tested materials (p>0.05). In Weibull analysis, TP showed the greatest Weibull modulus which means a higher reliability of the materials. Also, Gum-shade composite resins revealed a strong correlation in all flexural properties. There was a positive correlation in FS-FM ($r^2=0.99$) and a negative correlation between FS-WOF and FM-WOF ($r^2>0.97$). Therefore, this confirmed that flexural property was important for mechanical behavior evaluation and useful information. To addition, this improved among mechanical properties correlation of materials as important factor.

• Korean Journal of Head & Neck Oncology
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• v.12 no.2
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• pp.153-160
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• 1996

Regardless of the prognostic factors in papillary thyroid cancer, such as sex, age, size of tumor, extent of disease, and distant metastasis, the prognosis of papillary thyroid cancer is sometimes difficult to predict from clinical and microscopic analysis alone and additional prognostic indicators are needed. Recent studies of thyroid cancer have indicated that DNA aneuploidy may be correlated to the biological behavior of malignancy and inversely correlated to the prognosis, but it still remains contraversal. We performed this study to assess DNA ploidy patterns in relation with the previously known prognostic factors in AMES scoring system and lateral neck node metastasis in papillary thyroid cancer. A series of 132 patients with papillary thyroid cancer and 80 patients with benign thyroid tumor(27 follicular adenomas and 53 adenomatous goiters) as a control group from October 1993 to Feburary 1995 were analyzed and their nuclear DNA content was measured with flow cytometry using fresh tissue specimens. DNA aneuploidy was found in 8(6.1%) in papillary cancer and 8(10%) in benign tumor. S-phase traction(SFP) and proliferative index(PI) were higher in thyroid cancers, being 2.18$\pm$4.24%, 6.34$\pm$4.94% in the papillary thyroid cancers and 1.97$\pm$2.93%, 4.44$\pm$3.80% in the benign tumors, respectively. However there was no significant difference of values between two groups(p>0.05). Among variable prognostic factors studied(age, sex, size of tun or, extent of disease, distant metastasis in AMES scoring system and lateral neck node metastasis), DNA aneuploidy was found to be common in distant metastasis(p<0.001) and in lateral neck node metastasis(p>0.035), but there was no significant difference between the high risk and low risk group according to the AMES scoring system(p<0.08). In our study, DNA aneuploidy was not valuable in determining the presence of malignancy and did not correlate to the AMES scoring system. However, follow-up study of more cases will be needed for accurate information about the DNA ploidy as a independent prognostic factor.

• 한국해양학회지
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• v.30 no.3
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• pp.170-183
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• 1995

Eddies and surface current field in the southwestern part of the East Sea were investigated using satellite-tracked drifters, CTD, and ADCP from November 1992 to September 1993. Trajectories of surface drifters provided information for the first time on the meandering motion of the East Korean Warm Current in the Ullung Basin (referred as UB) and clearly indicated the existence of cyclonic and anticyclonic eddies of various scales. Anticyclonic eddies persisting for a relatively long period were observed in UB and the southwestern corner of the Northern (Japan) Basin (SNB), while a cyclonic eddy was found in the coastal area between Sokcho and Donghae during the summer. Analysis shows that the eddy in UB behaved as a stationary eddy at least during the observation period and the cyclonic eddy was closely related to the existence of a cold water mass. The anticyclonic eddy in SNB was larger than that in UB, but much elongated in shape. The eddy in UB is characteristic of major and minor axes of about 120 and 70 km, revolution period of 13.6 days, mean swirl velocity of about 24 cm/s, and mean eddy kinetic energy of 392 cm$\^$2//s$\^$2/. The eddy in SNB is described as follows; major and minor axes of 168 and 86 km, period of 14.9 days, mean swirl velocity of 29 cm/s and mean eddy kinetic energy of 629 cm$\^$2//s$\^$2/. The mean translational speed is about 3 cm/s for both eddies. The agreement of the surface current pattern in UB observed by ADCP with the geostrophic flow pattern may suggest that the eddy in UB was nearly in geostrophic balance. The eddy was found to be strongly bottom-controlled.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.5
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• pp.37-45
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• 2004

As Internet technologies are mature, many new applications that are different characteristics are emerging. Recently we see wide use of P2P(Peer to Peer) applications of which traffic shows different statistical characteristics compared with traditional application such as web(HTTP) and FTP(File Transfer Protocol). In this paper, we measured subscriber network of KT(Korea Telecom) to analyze P2P traffic characteristics. We show flow characteristics of measured traffic. We also estimate Hurst parameter of P2P traffic and compare self-similarity with web traffic. Analysis results indicate that P2P traffic is much bustier than web traffic and makes both upstream traffic and downstream traffic be symmetric. To predict parameters related QoS such as packet loss and delays we model P2P traffic using two self-similar traffic models and predict both loss probability and mm delay then compare their accuracies. With simulation we show that the self-similar traffic models we derive predict the performance of P2P traffic accurately and thus when we design a network or evaluate its performance, we can use the P2P traffic model as reference input traffic.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.12
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• pp.37-42
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• 1999

In this paper, some of main processes for the next generation integrated circuits, such as Cu damascene process using CMP, electron beam lithography, $SiO_2$ CVD and RIE, Ti/Cu-CVD were carried cut and then, two level Cu interconnects were accomplished. In the results of CMP unit processes, a 4,635 ${\AA}$/min of removal rate, a selectivity of Cu : $SiO_2$ of 150:1, a uniformity of 4.0% are obtained under process conditions of a head pressure of 4 PSI, table and head speed of 25rpm, a oscillation distance of 40 mm, and a slurry flow rate of 40 ml/min. Also 0.18 ${\mu}m\;SiO_2$ via-line patterns are fabricated using 1000 ${\mu}C/cm^2$ dose, 6 minute and 30 second development time and 1 minute and 30 second etching time. And finally sub-0.2 ${\mu}$ twolevel metal interconnects using the developed processes were fabricated and the problems of multilevel interconnects are discussed.

• Journal of the Economic Geographical Society of Korea
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• v.4 no.2
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• pp.79-96
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• 2001

This paper introduces a new type of industrial cluster developed at the CBD of Seoul. Conventionally, clusters are said to be consisted of hi-tech, often If activities, manufacturing industries or artisan craft industries with increasing vertical integration and performance usually supported by venture capitals and favorable business infrastructure, not to mention governments', be it central or local, incentive plans. The study area, Cheonggyechon region has long been a traditional CBD frame of Seoul, Korea, being troubled by deterioration, traffic jams, and environmental degradation as most inner cities experience. Recently. this region has transformed to the most dynamic and productive area not by IT industries but by apparel and fashion activities. The study of the developmental trajectory and key characteristics for this kind of industrial cluster can give us insight both for the transition of inner city and for the cluster theory. This Paper firstly briefly Profiles the growth of the Cheonggyechon region over the past decade. It then shows the current spatial and business structure of the new industrial cluster, focusing on the fact that transactions costs are reduced, the creation and flow of information improves. and the local institutions are prone to be most responsive to the new cluster's specialized needs. The third section presents the key components of the customized production-distribution-shopping cluster development process, emphasizing the localized networking. social capital, spontaneous institutionalization of associational economic climate, and cultural economy based on place-specific inertia. The paper concludes with some comments about the prospects and perils of the new industrial cluster of Seoul.

• Korean Institute of Interior Design Journal
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• v.20 no.4
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• pp.174-182
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• 2011

This study analyzed visitors' behaviors in the viewpoint of Attraction Power and Holding Power of exhibits on the basis of exhibition layout of real science museums. Through the analysis, the study grasped efficiency of analysis index and exhibition environment elements which might have an effect on planning the exhibition space of a large-scale museum and producing detailed ranges of exhibition. The main indicators used are: 1. Attraction Power: it indicates the relative incidence of people who have stopped in front of an object/exhibit during the exhibition tour. It is calculated by dividing the number of people who stop by the total number of people who have visited the museum or gallery. 2. Holding Power: it measures the average time spent in front of an information/communication element. It is calculated by dividing the average time of stay by the time "necessary" to read an element. As a result of analyzing the exhibition areas of National Science Museum (Daejeon) and National Museum of Emerging Science and Innovation(Tokyo), the Holding Power was found to be relatively lower than the Attracting Power. This means that 3.5 out of 10 visitors stop in front of the exhibit in 6 exhibition areas, and among these, only 1/10 is used when compared to the user required time of the exhibits. In other words, like the method of deriving an analysis index, the stage of viewing can be categorized as Attracting Power and Holding Power, and because the stage from Attracting Power to the stage of Holding Power are strongly linked, it shows that it is not easy to display a meaningful result. Except, the general distribution of Attracting Power was shown to be high from the entrance area of the exhibition hall based on the standard of viewing sequence. Also, the Holding Power became sequentially lower according to the sequence of exhibition viewing and displayed a meaningful interrelationship with the distribution ratio of island exhibits. In the case of island exhibition method, it is less influenced by the movement flow of visitors when compared to the wall type method of exhibition and can be understood as an exhibition method that provides spatial chances enabling stopping and viewing.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.125-131
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• 2015

Currently, taxol is mainly extracted from the bark of yews; however, this method can not meet its increasing demand on the market because yews grow very slowly and are a rare and endangered species belonging to first-level conservation plants. Recently, increasing efforts have been made to develop alternative means of taxol production; microbe fermentation would be a very promising method to increase the production scale of taxol. To determine the activities of the taxol extracted from endophytic fungus N. sylviforme HDFS4-26 in inhibiting the growth and causing the apoptosis of cancer cells, on comparison with the taxol extracted from the bark of yew, we used cellular morphology, cell counting kit (CCK-8) assay, staining (HO33258/PI and Giemsa), DNA agarose gel electrophoresis and flow cytometry (FCM) analyses to determine the apoptosis status of breast cancer MCF-7 cells, cervical cancer HeLa cells and ovarian cancer HO8910 cells. Our results showed that the fungal taxol inhibited the growth of MCF-7, HeLa and HO8910 cells in a dose-and time-dependent manner. IC50 values of fungal taxol for HeLa, MCF-7 and HO8910 cells were $0.1-1.0{\mu}g/ml$, $0.001-0.01{\mu}g/ml$ and $0.01-0.1{\mu}g/ml$, respectively. The fungal taxol induced these tumor cells to undergo apoptosis with typical apoptotic characteristics, including morphological changes for chromatin condensation, chromatin crescent formation, nucleus fragmentation, apoptotic body formation and G2/M cell cycle arrest. The fungal taxol at the $0.01-1.0{\mu}g/ml$ had significant effects of inducing apoptosis between 24-48 h, which was the same as that of taxol extracted from yews. This study offers important information and a new resource for the production of an important anticancer drug by endofungus fermentation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2169-2177
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• 2014

Matrine, a main active component extracted from dry roots of Sophora flavecens, has been reported to exert antitumor effects on A549 human non-small lung cancer cells, but its mechanisms of action remain unclear. To determine effects of matrine on proliferation of A549 cells and assess possible mechanisms, MTT assays were employed to detect cytotoxicity, along with o flow cytometric analysis of DNA content of nuclei of cells following staining with propidium iodide to analyze cell cycle distribution. Western blotting was performed to determined expression levels of Bax, Bcl-2, VEGF and HDAC1, while a microarray was used to assessed changes of miRNA profiles. In the MTT assay, matrine suppressed growth of human lung cancer cell A549 in a dose- and timedependent manner at doses of 0.25-2.5 mg/ml for 24h, 48h or 72h. Matrine induced cell cycle arrest in G0/G1 phase and decreased the G2/M phase, while down-regulating the expression of Bcl2 protein, leading to a reduction in the Bcl-2/Bax ratio. In addition, matrine down regulated the expression level of VEGF and HDAC1 of A549 cells. Microarray analysis demonstrated that matrine altered the expression level of miRNAs compared with untreated control A549 cells. In conclusion, matrine could inhibit proliferation of A549 cells, providing useful information for understanding anticancer mechanisms.