• Journal of KIISE:Computing Practices and Letters
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• v.8 no.4
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• pp.457-467
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• 2002

In order to simulate cyber attacks and predict network behavior by attacks, we should represent attributes of network components in the simulation model, and should express characteristics of systems that carry out various cyber attacks and defend from these attacks. To simulate how network load may change under the cyber attacks, we extended SSF[9, 10] that is process-based event-oriented simulation system. We added a firewall class and a packet manipulator into the SSFNet that is a component of SSF. The firewall class, which is related to the security, is to simulate cyber attacks, and the packet manipulator is a set of functions to write attack programs for the simulation. The extended SSFNet enables to simulate a network with the security systems and provides advantages that make easy to port already exsiting attack programs and apply them to the simulation evironment. We made a vitual network model to verify operations of the added classes, and simulated a smurf attack that is a representative denial of sevive attack, and observed the network behavior under the smurf attack. The results showed that the firewall class and packet manipulator developed in this paper worked normaly.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.6
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• pp.460-471
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• 2004

Since the RTP is suitable for real-time data transmission in multimedia services like VoD, AoD, and VoIP, it has been adopted as a real-time transport protocol by RTSP, H.323, and SIP. Even though the RTP protocol stack for embedded systems has been in great need for efficient support of multimedia services, such a stack has not been developed yet. In this paper, we explain embeddedRTP which supports the RTP protocol stack at the kernel level so that it is suitable for embedded systems. Since embeddedRTP is designed to reside in the UBP module, existing applications which rely ell TCP/IP services can proceed the same as before, while applications which rely on the RTP protocol stack can request HTP services through embeddedRTp API. EmbeddedRTP stores transmitted RTP packets into per session packet buffer, using the packet's port number and multimedia session information. Communications between applications and embeddedRTP is performed through system calls and signal mechanisms. Additionally, embeddedRTP API makes it possible to develop applications more conveniently. Our performance test shows that packet-processing speed of embeddedRTP is about 7.5 times faster than that oi VCL RTP for multimedia streaming services on PDA in spite that its object code size is reduced about by 58% with respect to UCL RTP's.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.104-111
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• 2005

Dmitri Donskoi, the Russian cruiser launched in 1883, is known to have sunk near Ulleung Island (East Sea, Korea) on May 29, 1905, while it was participating in the Russo-Japanese War. In order to find this ship, information about its possible location was obtained from Russian and Japanese maritime historical records. The supposed location of the ship was identified, and we conducted a five-year geophysical survey from 1999 to 2003. A reconnaissance three-dimensional topographic survey of the sea floor was carried out using multi-beam echo sounder, marine magnetometer, and side-scan sonar. An anomalous body identified through the initial reconnaissance survey was identified by a detailed survey using a remotely operated vehicle, deep-sea camera, and the mini-submarine Pathfinder. Interpretation of the acquired data showed that the ship is hanging on the side of a channel, at the bottom of the sea 400 m below sea level. The location is about 2 km from Port Jeodong, Uleung Island. We discovered 152 mm naval guns and other war materiel still attached to the hull of the ship. In addition, the remnants of the steering gear and other machinery that were burnt during the final action were found near the hull. Strong magnetic fields, resulting from the presence of volcanic rocks in the survey area, affected the resolution of the magnetic data gathered; as a result, we could not locate the ship reliably using the magnetic method. Severe sea floor topography in the gully around the hull gave rise to diffuse reflections in the side-scan sonar data, and this prevented us from identifying the anomalous body with the side-scan sonar technique. However, the sea-floor image obtained from the multi-bean echo sounder was very useful in verifying the location of the ship.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.197-206
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• 2018

BACKGROUND: The present study aimed to examine the crops capable of growing and adapting to the external environment and various stresses of reclaimed agriculture land for the development of high value-added agricultural utilization technology based on reclaimed land through standardization and empirical study of cultivation environment for cultivating crops. METHODS AND RESULTS: Two crops namely turnips and beets were selected for the salt tolerance test of soil environmental conditions on reclaimed land. Turnip and beet seedlings were planted on the soil collected at the 'Seokmun' reclaimed land. There are five treatments such as non-treatment, 1.0, 2.0 (control), 4.0 and $8.0dS{\cdot}m^{-1}$ of EC. The contents of betacyanin in beet roots was highest in control and decreased with increasing salt concentration. The GSL contents in the turnip roots waswere highest at EC 2.0 and decreased with increasing salt concentration, whereas those in turnip leaves waswere high both in the non-treated control and atthe EC 1.0-treatment. But, tThere was, however, no statistical differences among the treatments. CONCLUSION: The degree of salt tolerance of crops was examined, and the limit EC iswas expected to be $3.0{\sim}4.0dS{\cdot}m^{-1}$ as reported to date. If the soil improvement is performed and irrigation systems are used in the actual reclaimed land, the EC of supplied irrigation will be low, and desalination effecttreatment by the lower EC of the supplied irrigation on the soil will lead to more favorable soil condition of the rhizosphere and cultivation environment offor the crops than those in the port experiment. Therefore, monitoring the salinity, water content and ground water level will enable prediction of the rhizosphere environment, and setting up irrigation management and supplying irrigation will lead to crop cultivation results that are close to normal.

• Journal of Intelligence and Information Systems
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• v.29 no.3
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• pp.79-101
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• 2023

The current status of local road pavement management in Jeollabuk-do only relies on the accomplishments of the site construction company's pavement repair and is only managed through Microsoft Excel and word documents. Furthermore, the budget is irregular each year. Accordingly, a systematic maintenance plan for local roads is necessary. In this paper, data related to road damage and road environment were collected and processed to derive possible areas which could suffer from road damage. The effectiveness of the methodology was reviewed through the on-site inspection of the area. According to the Ministry of Land, Infrastructure and Transport, in 2018, the number of damages on general national roads were about 47,000. In 2019, it reached around 38,000. Furthermore, the number of lawsuits regarding the road damages were about 93 in 2018 and it increased to 119 in 2019. In the case of national roads, the number of damages decreased compared to 2018 due to pavement repairs. To measure the priorities in maintenance of local roads at Jeollabuk-do, data on maintenance history, local port hole occurrence site, overlapping business section, and emergency maintenance section were transformed into data. Eventually, it led to improvements in maintenance of local roads. Furthermore, spatial data were constructed using various current status data related to roads, and finally the data was processed into a new form that could be utilized in machine learning and predictions. Using the spatial data, areas requiring maintenance on pavement were predicted and the results were used to establish new budgets and policies on road management.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.126-139
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• 2022

This study aims to present the criteria of location selection and contents composition of Sewol ferry memorial space from the perspective of placeness and dark tourism, one of the main concepts of cultural tourism theory, and to draw academic concepts and implications related to it. First, the location selection of Sewol ferry memorial space was proposed by applying the concept of placeness to each important location, and the direction of the contents composition was presented based on the contents components such as characters, stories, places and dark tourism composition directions. As a result, when the Sewol ferry memorial space is designed in use of systemizing the narrative structure of the storytelling method and implementing it specifically, it is suggested that it is possible to construct a Sewol ferry memorial space by distributing and course-making based on the narrative structure rather than focusing on the location selection of a specific place. In addition, it was argued that the contents composition criteria should be more complex and systematically established and applied considering the connection between placeness and dark tourism when the Sewol ferry memorial space is constructed in various sites like 416 life safety parks and Mokpo New Port. This study, which aims to answer research questions related to major issues based on the perspective of placeness and dark tourism on the Sewol ferry memorial space, is expected to be used as a reference for the construction of the memorial space in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.950-957
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• 2023

For safe mooring and towing between the ship and port, the equipment must be designed in accordance with the relevant international regulations. However, some small shipyards and engineering companies often do not fully comprehend the core contents. Therefore, the international regulations regarding towing and mooring equipment are reviewed and the bollard and chock are newly developed based on the Mooring Equipment Guideline 4 (MEG4) standards. A bollard is a mooring equipment used to fix a mooring rope to the hull. It has two columns and is mostly used in a figure eight pattern knots under the mooring condition. The chock, which is used to change the mooring rope direction coming into the ship from outside, is manufactured using a casting with curvature. The two mooring equipment are widely used in the stern, bow, and mid-side. Owing to the increase in the size of container vessels and LNG ships, the mooring rope load has increased and the safe working load of the mooring equipment must be revised. This study summarizes and examines the results of the allowable stress method obtained using finite element analysis modelling. To consider the mesh size effect, a reasonable criteria was suggested by referring the existing class guidance. Additionally, the safe working load was verified through nonlinear collapse analysis, and the elastic region against load increments was confirmed. Furthermore, the proposed evaluation method can be used to develop similar equipment in the near future.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.344-352
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• 2023

Background: With its developed port and related industries, the concentration of fine dust is high in Busan compared to other cities in South Korea. Many studies have reported the health effects of fine dust, but there has been a lack of information regarding concentrations of volatile organic compounds among those who exposed to high levels of fine dust. Objectives: This study aimed to define an area with high concentrations of particulate matter and perform biomonitoring surveys among the residents of the area. Methods: Air quality data was collected and the mean level of each district in Busan was derived. We then defined the area with the highest concentrations of PM₁₀ as a target site. Urine samples were collected from the 400 participants and analyzed for VOCs metabolites - trans,trans-Muconic Acid (t,t-MA) and N-AcetylS-(benzyl)-L-cysteine (BMA). Interviews were conducted by trained investigators to examine demographic information. The levels of t,t-MA and BMA were compared with representative South Korean population data (Korean National Environmental Health Survey). The association of the VOC metabolites and fine dust were analyzed by general linear regression analysis. Results: The mean of PM₁₀ in the target site was 42.50 ㎍/m³ from 2018 to 2020. Among the 400 participants in the target site, 74.8% were female and the average age of the participants was 66 years. The geometric mean of t,t-MA was 71.15 ㎍/g creatinine and the BMA was 7.00 ㎍/g creatinine among the residents. The levels were higher than the geometric mean from the 4th KoNEHS. The levels of t,t-MA showed significance in BMI, smoking status, and household income. BMA showed significance in gender and age. Conclusions: Compared to the general population of South Korea, the target site's residents had higher biomonitoring levels. Based on this study, continuous screening for high risk areas, including the target site, and biomonitoring of the residents are required.

• Journal of the Korean Society of Systems Engineering
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• v.20 no.spc1
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• pp.12-29
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• 2024

The purpose of this study is to identify the social issues discussed in Korea regarding Maritime Autonomous Surface Ships (MASS), the most advanced ICT field in the shipbuilding industry, and to suggest policy implications. In recent years, it has become important to reflect social issues of public interest in the policymaking process. For this reason, an increasing number of studies use media data and social media to identify public opinion. In this study, we collected 2,843 domestic media articles related to MASS from 2017 to 2022, when MASS was officially discussed at the International Maritime Organization, and analyzed them using text mining techniques. Through term frequency-inverse document frequency (TF-IDF) analysis, major keywords such as 'shipbuilding,' 'shipping,' 'US,' and 'HD Hyundai' were derived. For LDA topic modeling, we selected eight topics with the highest coherence score (-2.2) and analyzed the main news for each topic. According to the combined analysis of five years, the topics '1. Technology integration of the shipbuilding industry' and '3. Shipping industry in the post-COVID-19 era' received the most media attention, each accounting for 16%. Conversely, the topic '5. MASS pilotage areas' received the least media attention, accounting for 8 percent. Based on the results of the study, the implications for policy, society, and international security are as follows. First, from a policy perspective, the government should consider the current situation of each industry sector and introduce MASS in stages and carefully, as they will affect the shipbuilding, port, and shipping industries, and a radical introduction may cause various adverse effects. Second, from a social perspective, while the positive aspects of MASS are often reported, there are also negative issues such as cybersecurity issues and the loss of seafarer jobs, which require institutional development and strategic commercialization timing. Third, from a security perspective, MASS are expected to change the paradigm of future maritime warfare, and South Korea is promoting the construction of a maritime unmanned system-based power, but it emphasizes the need for a clear plan and military leadership to secure and develop the technology. This study has academic and policy implications by shedding light on the multidimensional political and social issues of MASS through news data analysis, and suggesting implications from national, regional, strategic, and security perspectives beyond legal and institutional discussions.

• Clinical Endoscopy
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• v.55 no.3
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• pp.417-425
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• 2022

Background/Aims: Endoscopic submucosal dissection (ESD) for diverticulum-associated colorectal lesions is generally contraindicated because of the high risk of perforation. Several studies on patients with such lesions treated with ESD have been reported recently. However, the feasibility and safety of ESD for lesions in proximity to a colonic diverticulum (D-ESD) have not been fully clarified. The aim of this study was to evaluate the feasibility and safety of D-ESD. Methods: D-ESD was defined as ESD for lesions within approximately 3 mm of a diverticulum. Twenty-six consecutive patients who underwent D-ESD were included. Two strategic approaches were used depending on whether submucosal dissection of the diverticulum-related part was required (strategy B) or not (strategy A). Treatment outcomes and adverse events associated with each strategy were analyzed. Results: The en bloc resection rate was 96.2%. The R0 and curative resection rates were 76.4% and 70.6% in strategy A and 88.9% and 77.8% in strategy B, respectively. Two cases of intraoperative perforation and one case of delayed perforation occurred. The delayed perforation case required emergency surgery, but the other cases were managed conservatively. Conclusions: D-ESD may be a feasible treatment option. However, it should be performed in a high-volume center by expert hands because it requires highly skilled endoscopic techniques.