• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권2호
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• pp.191-204
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• 2010

There is a well-defined propagation model, named the random constant spread (RCS) model, which explains worms that spread their clones with a random scanning strategy. This model uses the number of infected hosts in a domain as a factor in the worms' propagation. However, there are difficulties in explaining the characteristics of new Internet worms because they have several considerable new features: the denial of service by network saturation, the utilization of a faster scanning strategy, a smaller size in the worm's propagation packet, and to cause maximum damage before human-mediated responses are possible. Therefore, more effective factors are required instead of the number of infected hosts. In this paper, the network bandwidth usage rate is found to be an effective factor that explains the propagations of the new Internet worms with the random scanning strategy. The analysis and simulation results are presented using this factor. The simulation results show that the scan rate is more sensitive than the propagation packet for detecting worms' propagations.

• 인터넷정보학회논문지
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• 제21권5호
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• pp.31-37
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• 2020

Last year's Goseong-Sokcho forest fires have highlighted the limitations of extinguishing work for night-time forest fire and the importance of quick identification for information on the spread of forest fire. However, it is not easy to find services that take into account the characteristics of forest fires, as most existing disaster-related mobile applications and research assume various disaster situations rather than just forest fire situations. Therefore, a system that can provide information quickly is needed, taking into account the characteristics of forest fires and the limitations of extinguishing work. In this paper, we propose evacuation route guidance services that bypass areas where fire has already spread, supplement existing methods of extinguishing work, and provide general information on forest fire situations in real time, by putting drones into forest fire situations. It has been implemented to automate image analysis using the Rekognition service of Amazon Web Service (AWS), and the results of fire detection and the T Map API guide the evacuation path. It is expected that the results of this paper will allow efficient and rapid rescue and extinguishing work to be carried out, and further reduce the damage of human life caused by forest fires.

• 대한가정학회지
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• 제45권2호
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• pp.105-117
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• 2007

The purpose of this study is to examine the producing conventions of lifestyle news and search for problems with these conventions. This research is about the entire process of production of lifestyle news, while dividing it into sourcing conventions and editing conventions. With this concept as a goal, we analyzed the content of lifestyle articles over the last six months in two types of daily papers, and then interviewed journalists in-depth. The results of the study indicate that as for sourcing conventions, reporting is accomplished by focusing on a reporter and using anonymous or false-named news sources. These conventions spread widely over not only ideas but also valuation of news items and security of news sources. This is because in terms of lifestyle news that is closely related to one's private life such as family relations, a reporter often attempts to prevent a news source from being exposed to secondary damage, such as the criticism of readers. In the meantime, editing conventions of lifestyle articles are irrelevant in terms of the quality of each media enterprise. Instead, these conventions are connected with the day of publication. Moreover, editors tend to approach editing conventions to spread the culture of upper classes, recognizing that the readers are consumers who have purchasing power.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.178-201
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• 2019

The appropriate design of a mooring system to maintain the position of an offshore structure in deep sea under various environmental loads is important. Fatigue design of the mooring line considering OPB/IPB(out-of-plane bending/in-plane bending) became an essential factor after the incident of premature fatigue failure of the mooring chain due to OPB/IPB in the Girassol region in West Africa. In this study, mooring line fatigue analysis was performed considering the OPB/IPB of a spread moored FPSO in deep sea. The tension of the mooring line was derived by hydrodynamic analysis using the de-coupled analysis method. The floater motion time histories were calculated under the assumption that the mooring line behaves in quasi-static manner. Additional time domain analysis was carried out by prescribing the obtained motions on top of the selected critical mooring line, which was determined based on spectral fatigue analysis. In addition, nonlinear finite element analysis was performed considering the material nonlinearities, and both the interlink stiffness and stress concentration factors were derived. The fatigue damage to the chain surface was estimated by combining both the hydrodynamic and stress analysis results.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.809-817
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• 2021

The worldwide spread of the COVID-19 pandemic has had a severe impact on the global economy. The COVID-19 pandemic has spread with alarming speed and. The economic damage is already evident and represents the largest economic shock the world has experienced in decades. This study analyzes the factors that influence behavior and its impact on start-up performance, through technology capabilities, technology development, organizational structure characteristics, and leadership technology. The mixed-method was used in this research to be applied to start-up companies in Jabodetabek with a population of 522 start-ups. Then the sample was selected through purposive sampling technique to obtain a sample of 187 start-ups. Primary data was collected through a questionnaire, then statistical analysis was carried out using Partial Least Square. There are ten variables used in the model as measured by the questionnaire. The results showed that the four factors (agility, entrepreneurship capability, business transformation, and opportunity) significantly influence start-up behavior. The results showed that the start-up behavior significantly influenced technology capabilities, technology development, organizational structure characteristics, and leadership technology. This study also found that start-up behavior had the greatest influence on organizational structure characteristics, partially affect start-up performance, but leadership technology does not have a significant effect on start-up performance.

• Journal of Forest and Environmental Science
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• 제40권1호
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• pp.24-34
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• 2024

Fire, being primarily a natural phenomenon, is impossible to control, although it is feasible to map the forest fire risk zone, minimizing the frequency of fires. The spread of a fire starting in any stand in a forest can be predicted, given the burning conditions. The natural cover of the land and the safety of the population may be threatened by the spread of forest fires; thus, the prevention of fire damage requires early discovery. Satellite data and geographic information system (GIS) can be used effectively to combine different forest-fire-causing factors for mapping the forest fire risk zone. This study mainly focuses on mapping forest fire risk in the Madikhola watershed. The primary causes of forest fires appear to be human negligence, uncontrolled fire in nearby forests and agricultural regions, and fire for pastoral purposes which were used to evaluate and assign risk values to the mapping process. The majority of fires, according to MODIS events, occurred from December to April, with March recording the highest occurrences. The Risk Zonation Map, which was prepared using LULC, Forest Type, Slope, Aspect, Elevation, Road Proximity, and Proximity to Water Bodies, showed that a High Fire Risk Zone comprised 29% of the Total Watershed Area, followed by a Moderate Risk Zone, covering 37% of the total area. The derived map products are helpful to local forest managers to minimize fire risks within the forests and take proper responses when fires break out. This study further recommends including the fuel factor and other fire-contributing factors to derive a higher resolution of the fire risk map.

• Journal of Information Processing Systems
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• 제5권1호
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• pp.33-40
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• 2009

Ever since the network-based malicious code commonly known as a 'worm' surfaced in the early part of the 1980's, its prevalence has grown more and more. The RCS (Random Constant Spreading) worm has become a dominant, malicious virus in recent computer networking circles. The worm retards the availability of an overall network by exhausting resources such as CPU capacity, network peripherals and transfer bandwidth, causing damage to an uninfected system as well as an infected system. The generation and spreading cycle of these worms progress rapidly. The existing studies to counter malicious code have studied the Microscopic Model for detecting worm generation based on some specific pattern or sign of attack, thus preventing its spread by countering the worm directly on detection. However, due to zero-day threat actualization, rapid spreading of the RCS worm and reduction of survival time, securing a security model to ensure the survivability of the network became an urgent problem that the existing solution-oriented security measures did not address. This paper analyzes the recently studied efficient dynamic network. Essentially, this paper suggests a model that dynamically controls the RCS worm using the characteristics of Power-Law and depth distribution of the delivery node, which is commonly seen in preferential growth networks. Moreover, we suggest a model that dynamically controls the spread of the worm using information about the depth distribution of delivery. We also verified via simulation that the load for each node was minimized at an optimal depth to effectively restrain the spread of the worm.

• 한국측량학회지
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• 제30권3호
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• pp.287-294
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• 2012

가축전염병 중 하나인 구제역의 경우 정보의 초동 대응 미흡 등으로 전국적으로 확산되는 피해를 초래하였다. 이를 해결하기 위해 국가에서는 가축이력에 대한 체계적인 관리를 마련하기 위하여 데이터를 구축하였으며, 2002년도부터 추진되어 현재 웹 기반의 가축전염병 발생 통계 시스템(AIMS)이 운영하고 있다. 이는 사용자가 원하는 기간에 해당 축종의 형태에 따른 질병을 선택하면 지역별로 가축전염병 발생 통계 현황이 텍스트 기반으로 제공하고 있다. 하지만 이 같은 경우 시각적으로 공간적인 위치정보를 즉각적으로 파악할 수 없기 때문에 정보를 효과적으로 전달하기 어렵고, 의사결정을 내리고자 할 때 사용자가 원하는 정보를 다차원적으로 지원하지 못하는 한계가 있다. 이 연구에서는 오픈소스 기반의 SOLAP(Spatial On-Line Analytical Processing) 기술을 적용하여 여러 형태의 데이터를 다각적인 방법으로 분석하고, 최종적으로 나온 결과를 공간정보와 통합하여 지도상에 시각적으로 전달되도록 표현하였다.

• 한국화재소방학회논문지
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• 제32권4호
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• pp.75-85
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• 2018

2016년 6월 영국 그렌펠 타워 화재는 외단열에 의한 수직화재확산으로 인한 대표적인 피해사례이다. 외단열 공법에서 많이 사용되는 유기단열재는 단열성능이 좋은 반면 화재에 취약한 단점이 있다. 알루미늄 복합패널을 외벽 마감재로 사용하는 외단열 공법에서 알루미늄 내부에 사용되는 플라스틱은 수직 화재확산의 원인으로 지목되고 있다. 알루미늄복합패널을 외벽에 고정하기 위해 사용되는 철재 프레임 때문에 외벽과 외벽 마감재 사이에 중공층이 형성된다. 외벽에 화재가 발생하면 가연성외벽의 연소뿐만 아니라 단열재로부터 발생된 화염이 중공층을 통해 수직으로 급격히 확산되어 인명 및 재산피해가 발생할 수 있다. 국내의 경우 국토교통부고시 2015 - 744에 의한 소재단위 성능시험이 수행되고 있으며, 영국에서는 실제 규모의 화재시험으로 외벽의 수직화재확산 시간의 측정이 가능한 BS8414 시험이 시행되고 있다. 본 연구에서는 현행 국내 고시 기준으로 적합한 준불연 소재의 알루미늄복합패널을 대상으로 영국에서 시행되고 있는 실규모 외벽화재시험(BS 8414)을 수행하여 수직화재확산에 대한 거동 관찰과 현재 마감재료의 소재단위 평가의 한계를 확인하고자 하며, 실제 규모의 화재 시험을 통한 외벽화재 화재확산 방지를 위한 시스템 도입 필요성 확인하고자 한다.

• 대한공간정보학회지
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• 제23권1호
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• pp.65-71
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• 2015

여름철이 되면 매년 남해안에서 발생되고 있는 적조현상은 양식장을 운영하는 어민들에 막대한 피해를 주고 있으며 이를 방재하기 위한 노력이 다각도로 진행되고 있다. 특히 위성영상을 이용한 적조 모니터링은 발생해역 전반에 걸친 적조발생자료를 취득할 수 있어서 방재 계획수립에 중요한 정보를 제공하여 줄 수 있다. 따라서 본 연구에서는 천리안 GOCI영상을 이용하여 하루 중 적조의 확산과 감소를 모니터링할 수 있는 결과를 제시하기 위하여 경상남도 남해안 지역을 선정하고 2013년(8월 12일), 2014년(9월 11일) GOCI영상자료를 분석한 결과 다음과 같은 결론을 얻었다. 남해안 해역의 적조발생 패턴은 오전에 거제도 남부해역에서 출현하여 점점 더 확산되다가 오후 1시에 최대가 되고 그 후 서서히 감소되는 경향을 보여주었다. 또한 하루 중 적조의 중심 이동은 거제시 남부해역에서 적조가 시작하여 서쪽으로 이동하다가 정오를 기하여 다시 동쪽으로 이동하는 경향을 보여주었다. 향후 적조 생물의 특성과 해수유동, 태양 일조량, 그리고 해수온도 등 많은 요인에 대한 추가적인 연구가 필요하다고 판단되지만, GOCI 영상을 이용한 적조이동 모니터링은 적조의 확산과 이동을 예측하여 방재하고 관리하는데 매우 중요한 정보가 될 것으로 생각된다.