• Convergence Security Journal
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• v.21 no.2
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• pp.11-18
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• 2021

To protect tangible and intangible assets, most of the companies are conducting information protection monitoring by using various security equipment in the IT service network. As the security equipment that needs to be protected increases in the process of upgrading and expanding the service network, it is difficult to monitor the possible exposure to the attack for the entire service network. As a countermeasure to this, various studies have been conducted to detect external attacks and illegal communication of equipment, but studies on effective monitoring of the open service ports and construction of illegal communication monitoring system for large-scale service networks are insufficient. In this study, we propose a framework that can monitor information leakage and illegal communication attempts in a wide range of service networks without large-scale investment by analyzing 'Netflow statistical information' of backbone network equipment, which is the gateway to the entire data flow of the IT service network. By using machine learning algorithms to the Netfllow data, we could obtain the high classification accuracy of 94% in identifying whether the Telnet service port of operating equipment is open or not, and we could track the illegal communication of the damaged equipment by using the illegal communication history of the damaged equipment.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.5
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• pp.203-216
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• 2021

Analyzing various wave interactions with oscillating wave surge converters (OWSC) is essential because they must be operated efficiently under a wide range of wave conditions and designed to extract optimal wave energy. In the conceptual design and development stage of OWSC, numerical analysis can be a good alternative as a design tool. This study performed a numerical analysis on the behavioral characteristics of the inverted triangle flap against the incident waves using open source CFD to examine the essential behavioral attributes of OWSC. Specifically, the behavioral characteristics of the structure were studied by calculating the free water surface displacement and the flap rotation angle near the inverted triangular flap according to the change of the period under the regular wave conditions. By comparing and examining the numerical analysis results with the hydraulic model experiments, the validity of the analysis performed and the applicability in analyzing the wave-structure interactions related to OWSC was verified. The numerical analysis result confirmed that the hydrodynamic behavior characteristic due to the interactions of the wave and the inverted triangle flap was well reproduced.

• Korean Institute of Interior Design Journal
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• v.22 no.3
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• pp.164-173
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• 2013

This study starts from the genealogical analysis of the urban public spaces through local history of Seoul which is significantly different from western countries. The analysis targets the discourse on the urban street, the basic unit of urban tissue and the settlement condition in urban life, which defines urban space-structure among the urban public spaces. And this research classifies and categorizes the value recognition and policy value occurred each period. Based on these, this research defines the progress levels of urban public design policy in Seoul as follows. Results Firstly, 1890's and 1900's was the period of development in commerce and industry, which caused congested and crowded streets. The open port policy allowed the experience of the foreign circumstance, and thus the identity of the urban streets and the value of symbolism come to realize among the society. During the Japanese colonization, urban streets put on modernized images through the urban remodeling out of the context according to the colonization policy. The brand-new values such as publicness and amenity are injected as well as modern regulations by system and authority. From Liberation to 1950's, it performed only street restoration as a repair from war with Japanese colonial system because of the political confusion and administrative vacuum. Finally, each period can be defined as follows. 1890's and 1900's can be defined as 'spontaneous finding the modernization' because urban street was intentionally transformed by the empire. Period of the Japanese colonization can be defined as 'the formation of modernized urban street concept and the compulsion of modernized regulation.' And period of from Liberation to 1950's, can be called as 'the absence of value recognition and maintenance of colonial system.' methodology.

• Journal of Chest Surgery
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• v.29 no.1
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• pp.107-111
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• 1996

Persistent bronchopleural fistula (BPF) still presents a troublesome therapeutic challenge and demands an aggressive approach when conventional measures fail. A 50-year-old man had a rigtlt pneumonectomy for far-advanced pulmonary tuberculosis with the development of postopneumonectomy empyema and BPF 1 month postoperatively in October 1 81. The condition was managed with BPF closure and the Clagett procedure, which failed with the recurrence of BPF and empyema, followed by a spontaneous open window at about 1 year port:operatively. The BPF, which had been aggravated to a large size, was managed by the closure and obliteration of the empyema cavity using a Pectoralis-skin pedicled flap 13 years postoper atively on Jul, 1994. The BPF was controlled by the procedure, and the patient, with improved respiratory symptom, was discharged 43 days postoperatively. We conclude that the use of myocutaneous flap Is an effective procedure for the closure of a large BPF. The surgical technique of the pedicled flap operation is described and the case is reported.

• Journal of Chest Surgery
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• v.46 no.2
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• pp.93-97
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• 2013

Background: Minimally invasive cardiac surgery has emerged as an alternative to conventional open surgery. This report reviews our experience with atrial septal defect using the da VinciTM surgical robot system. Materials and Methods: This retrospective study included 50 consecutive patients who underwent atrial septal defect repair using the da VinciTM surgical robot system between October 2007 and May 2011. Among these, 13 patients (26%) were approached through a totally endoscopic approach and the others by mini-thoracotomy. Nineteen patients had concomitant procedures including tricuspid annuloplasty (n=10), mitral valvuloplasty (n=9), and maze procedure (n=4). The mean follow-up duration was $16.9{\pm}10.4$ months. Results: No remnant interatrial shunt was detected by intraoperative or postoperative echocardiography. The atrial septal defects were mainly repaired by Gore-Tex patch closure (80%). There was no operative mortality or serious surgical complications. The aortic cross clamping time and cardiopulmonary bypass time were $74.1{\pm}32.2$ and $157.6{\pm}49.7$ minutes, respectively. The postoperative hospital stay was $5.5{\pm}3.3$ days. Conclusion: The atrial septal defect repair with concomitant procedures like mitral valve repair or tricuspid valve repair using the da VinciTM system is a feasible method. In addition, in selected patients, complete port access can be helpful for better cosmetic results and less musculoskeletal injury.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.433-439
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• 2012

In this paper, we proposed the triplexer using unit-cell of CRLH transmission line which has a bandpass characteristic to reduce adjacent channel interference. The input impedance of triplexer with each channel filter is operated open-circuit at the resonance frequencies of other channels. Such property is due to the combination a series and parallel resonance circuits of CRLH-TL unit-cell. The measured triplexer results are showed a measured insertion loss of each channel, less than 1.5 dB, matching at each port, less than 15dB and isolation between channel, better than 25 dB. Also, to validate the triplexer, a small signal amplifier with triple-band is designed and tested. the measured amplifier results show good agreements with prediction.

• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.479-486
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• 2003

As the Internet appliances like digital TV, Internet set-top boxes, and Internet phone, are showing up in the market, the economics of real-time operating system (RTOS), which is an essential for controlling those devices, is expanding faster than ever before. ETRI has developed describes RTOS called Qplus-P, targeting various platforms ranging from PDA to Internet set-top box and home server. This paper describes the implementation of graphic window library for Qplus-P. The Qplus-P graphic window library was implemented using tiny-X graphic server and gtk graphic toolkit, which are open source software. To port this library to various aliances, hangul processing, screen rotation, touch screen, and graphic acceleration functions are added to the tiny-X graphic server of the implementd graphic window library. Currently, Qplus-P graphic window is running on ARM-based appliances such as iPaq PDA, Samsung S3C2400 board, Zaurus PDA, and on Home Server that uses x86 processor. Qplus-P graphic library is provided as a of Qplus-P target builder.

• Publications of The Korean Astronomical Society
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• v.34 no.3
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• pp.49-65
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• 2019

We investigate the provenance and the changes in the timekeeping system focusing on official records such as almanacs and textbooks published by the government after the solar calendar was introduced. We found that the solar calendar and the 12-hour clock time first appeared in 1884 during Joseon dynasty, at that time the solar calendar was used at the open port in Busan to facilitate the exchanges with Japan. The 12-hour clock time first appeared in the 『Hansung Sunbo』 published by the government in 1884. We also found that the Joseon dynasty also used 12 diǎnzhōng or 12 diǎn. In addition, the term of the 'Sigan' first appeared in the first official academic textbook in August 1895, and the chapter related to time contained the information about 12-hour clock time instead of the 12 Shi. In 1908, the meaning of the solar time, the equation of time, and the differences in longitude with the adoption of Korean Standard Time were introduced. Meanwhile, the 24-hour clock time was first introduced in Joseon and applied to railway times in 1907. The 1946 almanac, the first issue after liberation, used the 12-hour clock time which uses 'Sango', 'Hao' and the 24-hour clock time started to be used from the following year and is still used to this day. Finally, the 12-hour clock time, which was introduced around 1884, was enacted as Article 44 of the law in 1900 and was revised again in 1905 and 1908. In Korea, the terms related to the time in the current astronomical calendar system were newly defined around 1884, 1896, and 1908, and gradually standardized through the establishment of laws.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3
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• pp.76-82
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• 2001

Most fluid machines can be considered as periodic noise sources when operated under constant conditions, which allows for a frequency domain representation of the source and the associated acoustic field In the duct. In such a representation, the source is characterized by frequency-dependent values of both strength and impedance. Although knowledge of these values can be gained by either experimentation or by modeling, one-port acoustic characteristics of an in-duct source with high flow velocity, high temperature, and high sound level can be measured only by the multiload method using an overdetermined set of open pipes with different lengths as applied loads. However, the problem is that negative source resistances have been often measured. This paper reviews the possible causes of the problem, with reference to experimental and theoretical results, in an attempt to clarify the issue. A new interpretation is given for the violation of basic assumptions and the defect in the algorithm of multiload method. The major cause and mechanism of the problem is due to the violation of time invariance assumption of the source and the load impedance can seriously affect the final measured result of source impedance.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.6
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• pp.349-356
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• 2013

The purpose of this study is to review and overcome the limits of the existing design wave model applied to such waters as those located inside bays or near islands where the impact of wind influenced waves are more dominant, due to the nature of topographic isolation, than the influence of direct waves coming from the open sea. Although the existing model for an inside bay design wave is excellent for considering wind factors and very adaptable to topographically complicated areas compared to other models, it is difficult to show the wave diffractions and reflections caused by large scale structures or topographic features in the region. The study examined the various methods capable of taking into account wave diffraction, the angle of wave reflection, and changes in water depth. As a result of applying the modified design wave model to the target situation (inside bay or near island areas), it was found that the reliability of the design wave height around marine structures was improved, compared to the existing models. Therefore, it is fair to predict that the new model could provide more accurate design waves in the design of marine structures.