• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.65-72
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• 2004

The Internet is a social and economic foundation, apparently destined for human communication and interaction. It is supposed to allow for more interactive and innovative ways for people to do what they do in 'real lift'. There is no shilly-shallying to say that at present, Internet has become a commanding and useful tool for empowerment and income making in developing countries. It is very difficult to say that at present internet has turned into a popular and useful thing among the Bangladeshi people like students, doctors, engineers, businessmen, researchers as well as politician who are being logged into the internet for getting information what they want. Though the Internet was invented in 1970 but it came late in Bangladesh through UUCPs (Unix-to-Unix copy) email connectivity in 1993 and IP connectivity in 1996. Having launched Internet, on June 1996 National polls result were broadcast through the using of World Wide Web (WWW) that was the first ever practice trial in Bangladesh. On June 1996, the government has approved to allow VSAT (Very Small Aperture Terminal) in the country's private sector to operate as Internet Service Provider (ISPs). At the end of year, there were only two ISPs in the country and number of users near about one thousand only. But next year in 1997, the total number of ISPs was more than a dozen and the clientele growth was ten times higher than that of the previous year. From then, the number of Internet users and ISPs are increasing significantly in Bangladesh. About 40 ISP are providing internet service among as many as 3, 20,000 users at present out of almost 130 license holder ISP provider but among the ISPs, most of the ISPs are placed in Dhaka and few are working in Comilla, Sylhet, Rajshahi, Chittagong and Khulna. It should be mention that currently, broadband internet (Radio, Cable) connection is working side by side dial -up connection where broadband accounts 10,000. This paper will have a comprehensive discussion on the current situations of Internet and some of the contemporary issues in the matter concerned.

• Journal of KIISE:Software and Applications
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• v.32 no.10
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• pp.963-973
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• 2005

Increasing attention is being recently devoted to various problems inherent in the topological design of networks systems. The topological structure of these networks can be based on service centers, terminals (users), and connection cable. Lately, these network systems are well designed with tiber optic cable, because the requirements from users become increased. But considering the high cost of the fiber optic cable, it is more desirable that the network architecture is composed of a spanning tree. In this paper, we present a GA (Genetic Algorithm) for solving bicriteria network topology design problems of wide-band communication networks connected with fiber optic cable, considering the connection cost, average message delay, and the network reliability We also employ the $Pr\ddot{u}fer$ number (PN) and cluster string in order to represent chromosomes. Finally, we get some experiments in order to certify that the proposed GA is the more effective and efficient method in terms of the computation time as well as the Pareto optimality.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.150-155
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• 2006

Purpose: The purpose of this study is to assess the results of the autologous osteochondral grafting harvested from medial side of talus for relatively large osteochondral lesion of the medial talar dome. Materials and Methods: From October 2004 to September 2005, 12 patients with osteochondral lesion measured more than 10 mm in axial MRI who were followed up more than 1 year after operation were analyzed. We evaluated postoperative symptoms by Mann and Reynolds scale, morbidity of donor site, and compared the range of both ankle motion. We also evaluated the union at the medial malleolar osteotomy site, trabecular connection between the grafted osteochondral mass and talus, irregularity of the articular surface in lesion. Results: Clinical results were rated as excellent in 4, good in 7, fair in 1. The mean angle of the total range of motion in affected ankle was decreased by 3 degrees compared to that in unaffected ankle. We did not observe abnormal findings at donor site. The osteotomized bone was united at mean 9 weeks (range, 8-12 weeks). We observed trabecular connection between grafted osteochondral mass and talus at mean 14 weeks (range, 12-16 weeks). We also observed irregular articular surface in osteochondral lesions in 6, smooth articular surface in 6. Conclusion: The local autologous osteochondral graft for relatively large osteochondral lesion of the medial talar dome is useful operative method with advantages of wide operative field, low morbidity of donor site, and high satisfaction rate.

• Journal of Chest Surgery
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• v.24 no.1
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• pp.15-25
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• 1991

From February 1988 to December 1990, 42 patients underwent so called REV operation for pulmonary stenosis or atresia with or without anomalies of ventriculoarterial connection and truncus arteriosus. The principles of operative technique are mobilization of pulmonary arterial tree beyond the pericardial reflection, transection of pulmonary trunk between the pulmonary ventricle and pulmonary artery, suture of distal pulmonary arterial stump to the upper margin of Pulmonary ventriculotomy site with absorbable suture, and anterior patch with 0.625% glutaraldehyde fixed autologous pericardium with monocusp inside it. Age at operation ranged 3-156months [mean 41.8 month] with twelve of whom infants. Operative indications were pulmonary atresia, with ventricular septal defect[16], and pulmonary stenosis with double outlet right ventricle[8], with ventricular septal defect[16], with double outlet right ventricle[8], with complete transposition of the great arteries[8], with corrected transposition of the great arteries[6], with Fallot`s tetralogy[3], and truncus arteriosus[1]. There were six hospital deaths[14%] and no late death. Twenty-four of 36 survivals were followed up more than 12 months with good clinical results. Postoperative angiocardiogram was performed in fifteen patients. Hemodynamically, two patents had residual pressure gradients along the pulmonary outflow tract, one patient showed severe pulmonary regurgitation; morphologically, there were six significant stenosis of left pulmonary arterial tree, two of whom showed significant pressure gradients. Our present experience with REV operation suggests that this technique make it possible to perform anatomic repair in a wide variety of congenital anomalies of abnormal ventriculoarterial connection associated with pulmonary outflow tract obstruction without using the prosthetic material, even in infants, with relatively low mortality and morbidity.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.101-114
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• 2002

The real multimedia application in wide area communication needs the guaranteed performance of communication service. Therefore, the resource is reserved at the moment of traffic burst and the region of connection admission possibility is widened at the basis of maximum cell rate. This of study shows that the end-to-end traffic delay to the traffic of burst state is guaranteed when the total of maximum transmission rate is higher than link speed by using the region of deterministic delay. The network load rate of connection admission can be improved by the inducement of delay bounds consideration each traffic characteristic to guarantee the end-to-end delay of network from single switch. This suggested buffering system using deterministic service do not give any influence to service quality and can guarantee the bounds of end-to-end delay. And it can also reduce the load of network even if the delay is increased according to the burst traffic characteristic. The above suggested system can be applied effectively to the various kinds of general network specification which admit both real time trafnc service and non-real time traffic service.

• Journal of Platform Technology
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• v.11 no.3
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• pp.76-82
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• 2023

Starting from the 4th industrial revolution, core technologies were applied to industries to build various smart environments. Smart factories in the manufacturing industry produce high-quality products by applying IIoT as a core technology that can collect and control a wide range of data for customized production. However, the network environment of the smart factory converted to open through IIoT was exposed to various security risks. In accordance with security breaches, IIoT has shown degradation in the quality of manufactured products and production processes due to network disturbance, use and maintenance of forged IIoT, and can cause reliability problems in business. Accordingly, in this study, a method for safe connection and utilization of IIoT was studied during the initial establishment of a smart factory. Specifically, a study was conducted to check the IIoT connection situation so that the practicality of the IIoT connected to the smart factory could be confirmed and the harmless environment established.

• The Journal of Information Systems
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• v.32 no.3
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• pp.151-164
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• 2023

Purpose This study aims to analyze the current status of consumer awareness on Internet banks by conducting a full investigation and collecting user opinions presented on Google Play. After cateogorizing the current dissatisfaction, we would like to present not only the direction of the Internet bank service of but also the improvements of the platform. Design/methodology/approach Using opinion mining, subjectivity analysis, polarity analysis, and polarity information analysis of comments were conducted step by step to extract negative and positive keywords. The extracted keywords analyzed the weights of the frequently appearing positive and negative keywords using the TF-IDF model. Based on previous studies that negative information is more sensitive to positive information, we tried to confirm the connection, proximity, and mediation of negative keywords. Semantic Network Analysis (SNA) was used to visualize the connection relationship between the negative comment keywords of the three Internet banks. Findings Domestic Internet banks such as Kakao Bank, K-Bank, and Toss Bank have attracted a lot of attention even before they were established, and after establishment, they have secured a wide range of users through platforms that are completely different from existing banks. This study found out that the convenience of the app affects the opening and transaction of non-face-to-face accounts, which are characteristics of domestic Internet banks, which also affects the bank's business strategy. In addition, this study shows that the business characteristics of the company can be identified.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.1-12
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• 2010

The existing survey of the actual use relevant transportation, implemented in order to reflect transportation policy, has been performed for users by researcher directly, or thereby analysing the data of particular date-oriented of transportation card business's content so that such method have many problems. To solve such problem, we developed a new system, Interoperable Traffic Information Collection System which include several functions of effective collecting of transportation use-data created from the Nation-wide Interoperable Transportation System, accurate counting and easy inquiry. This system consists of Link-server to collect and count for transportation use-data, DB-server to store for this data and Inquiry terminal to search for the information needed. To verify for developed this system, we run test-bed by connection between this system and the Nation-wide Interoperable Transportation System developed by the KOREA Financial Telecommunications & Clearings, the KORAIL NETWORKS and the HiPlusCard. And through result of test-bed, we proved that Interoperable Traffic Information Collection System practically works well. Thus we can look for systematic reflect of reliable information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.504-509
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• 2019

Recently, both wireless communications technology and the performance of small devices have developed exponentially, while the number of services using various types of Internet of Things (IoT) devices has also massively increased in line with the ongoing technological and environmental changes. Furthermore, ever more devices that were previously used in the offline environment-including small-size sensors and CCTV-are being connected to the Internet due to the huge increase in IoT services. However, many IoT devices are not equipped with security functions, and use vulnerable open source software as it is. In addition, conventional network equipment, such as switches and gateways, operates with vulnerabilities, because users tend not to update the equipment on a regular basis. Recently, the simple vulnerability of IoT devices has been exploited through the distributed denial of service (DDoS) from attackers creating a large number of botnets. This paper proposes a system that is capable of identifying Internet-connected devices quickly, analyzing and managing the vulnerability of such devices using Internet-wide scan technology. In addition, the vulnerability analysis rate of the proposed technology was verified through collected banner information. In the future, the company plans to automate and upgrade the proposed system so that it can be used as a technology to prevent cyber attacks.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.253-256
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• 2012

We present the IRC images of M51, a pair of interacting galaxies. Given the high angular resolution (7.4") and the wide field of view (~ 10') covering almost the entire M51 system, we investigate dust properties and their connection to the spiral arm structure. We have applied image-filtering processes including the wavelet analysis to the N3 image, which traces the total stellar mass best among the IRC bands. From this filtered image, the center, arm, and interarm regions are defined. A color, or flux ratio among the MIR bands, has been measured at each pixel (3.7" in size). We find a wide variety of S7/S11 with a difference between arm and interarm regions. We also find that at some positions S11 seems to be higher than predicted by MW dust models. Estimated contributions from the stellar continuum and gas emission lines to the band are not enough to explain this discrepancy. From these results, we deduce that the PAH ionization condition and its fraction to the total dust mass in M51 are different from those in MW.