• 한국지구과학회지
• /
• 제39권1호
• /
• pp.23-45
• /
• 2018

Moderately diverse, but very abundant trace fossils are found from the Late Pleistocene deposits of Jeju Island, Korea. Vertical I-, Y- and U-shaped domichnia of annelids or decapods are, over 2500, extremely abundant, 3D network domichnia of callianassids are, over 200, very abundant, and small sinuous trails of nematode repichnia are, over 50, abundant in number. Horizontal trails attributable to polychaete or worm-like animals are, less than 50, common, but horizontal spreiten burrows, fish traces and crab trackways are, less than 10, rare in occurrence. Of these trace fossils, Taenidium barretti, Undichna britannica and Undichna unisulca represent the first record from the Pleistocene in Asia. Psilonichnus upsilon is the second record in Asia. Crab trackways probably produced by underwater punting gait of sideway walking crabs may represent the first record in the world. In addition, diverse and very abundant footprints of more than 500 hominids, more than 200 birds and more than 1000 mammals are closely associated with these invertebrate trace fossils. Trace fossil assemblage integrated with sedimentary facies is interpreted to have been formed in the marginal marine foreshore to backshore environment corresponding to the Psilonichnus and Skolithos ichnofacies.

• Journal of Mechanical Science and Technology
• /
• 제14권9호
• /
• pp.956-967
• /
• 2000

In this paper, we explore the issues of force display in the cooperative virtual environment shared by multiple users distributed over the network with heterogeneous hardware platforms. The proposed method is to cope with the problem of small time delay and the difference of sampling rate in the distributed configuration. In the proposed approach the interaction forces of the participants are just treated as the independent sources of acceleration. Thus the action of a participant simply changes the acceleration of the virtual object and consequently the states of the virtual object will be updated. When the updated states are reported to all the participants, the information on the time of state changes is delivered, too. Employing the discrete state information updated by the other users, each user modifies his own virtual environment and pseudo-realtime simulation can be realized. Excluding the software interface and the communication technique, it is proposed the simulation method for the operation of respective users and the way of calculating the driving input to the display device. For experimental verification we construct a cooperative virtual environment shared by two remote users and outline the results of experiments.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2004년도 춘계학술대회 논문집
• /
• pp.365-370
• /
• 2004

At the present, e-commerce takes the place of existing transaction form in structure in the world trade by advancement of Information Technology and diffusion of Internet. There is no exceptions of this tendency even in industry of maritime and logistics. So, global shipping lines and logistics companies try to construct the e-Business network system for increasing their competitiveness in an are of cyber. However, in Korea, most of companies prefer "final handshake" as the traditional way of transaction to "e-commerce", because they bear a distrust in mind about the outflow of transaction information and security of settlement. So, number of companies using e-commerce is very small, and this situation causes the limited factor for activating the transaction structure of it. The rate of using e-commerce in logistics industry is lower than other industries, even more higher effectiveness is expected when they use it. Especially, it is very necessary not only e-commerce but also e-Logistics which can serve information of freight cost on cargo flow, operation cost and schedule, and tracing information of cargo. Increasing the necessity of e-Logistics, this study research the rate rf using e-Logistics focused on maritime and logistics companies, and analyze the transaction form among members of these industries for improving them. In detail, this paper examine the drivers for activating e-Logistics, and present the effective factors for a successful development of these industries.

• 정보보호학회논문지
• /
• 제23권6호
• /
• pp.1169-1180
• /
• 2013

Emulab은 미국 Utah 대학에서 개발된 연구 프레임워크로써 연구자들에게 필요한 시스템을 원하는 네트워크 구조로 연결하여 주는 On-demand 서비스를 그 핵심으로 하고 있다. 특히 Emulab은 시뮬레이션 또는 가상화 기술을 사용하지 않고 실제 시스템에 운영체제를 구동시킴으로써 연구의 검증환경을 실제 환경에 가깝게 하는 것이 특징이다. 이로 인해 Emulab은 사이버 보안 분야뿐만 아니라 네트워크 분야 등에서도 다양하게 활용되고 있었지만 국내에는 활용된 바가 거의 없었다. 최근 한국과학기술정보연구원(KISTI)에서 소규모 Emulab을 자체적으로 구축 운영함에 따라 국내에서도 Emulab을 활용한 연구가 활성화 될 것으로 기대된다. 이를 기점으로 본 논문은 Emulab을 국내에 소개하고, 사이버 보안 연구 프레임워크로써의 Emulab 활용 동향을 소개한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권10호
• /
• pp.5143-5158
• /
• 2018

Improving the intrusion detection system (IDS) is a pressing need for cyber security world. With the growth of computer networks, there are constantly daily new attacks. Machine Learning (ML) is one of the most important fields which have great contribution to address the intrusion detection issues. One of these issues relates to the imbalance of the diverse classes of network traffic. Accuracy paradox is a result of training ML algorithm with imbalanced classes. Most of the previous efforts concern improving the overall accuracy of these models which is truly important. However, even they improved the total accuracy of the system; it fell in the accuracy paradox. The seriousness of the threat caused by the minor classes and the pitfalls of the previous efforts to address this issue is the motive for this work. In this paper, we consolidated stratified sampling, cost function and weighted Support Vector Machine (WSVM) method to address the accuracy paradox of ID problem. This model achieved good results of total accuracy and superior results in the small classes like the User-To-Remote and Remote-To-Local attacks using the improved version of the benchmark dataset KDDCup99 which is called NSL-KDD.

• Journal of Contemporary Eastern Asia
• /
• 제13권2호
• /
• pp.41-56
• /
• 2014

This research paper advances our understanding of complex interdependence among countries. Existing research has found that total factor productivity (TFP), the residual from the economic growth function, is hindered in the absence of a country's strong political and legal institutions or if a country does not already have a sufficiently high level of TFP. We also know that regional efforts to eliminate pollution are complex. Bridging these two areas while focusing on a high polluting yet high innovating region, the following research questions are posed: Are Northeast Asian countries key collaborators in pursuit of green R&D? Are Northeast Asian countries collaborating extensively with each other? What are the implications for other regions' attempts to establish these kinds of relations? To answer the above questions, biofuels-related technology as defined in the International Patent Classification's "green inventory" of environmentally sound technologies is examined. Patent data is drawn from the USPTO and inventors' country origin as the unit of analysis. For the 1990-2013 period, the Northeast Asian countries are in the core of a small set of collaborating countries. There is evidence that their centrality has increased in recent years. Most importantly, East Asia is becoming a singular research hub in terms of biofuels-related R&D, offering a counter in the foreseeable future to the dominance of the American and European research network hubs.

• 전기전자학회논문지
• /
• 제13권3호
• /
• pp.39-46
• /
• 2009

무선 센서 네트워크는 무선 네트워크 기능이 있는 소형 장치로 구성된다. 실제 현장에서 센서 네트워크의 응용 영역을 증가시키기 위해서는 에너지 소모를 최소화 하는 것이 가장 큰 문제이다. 그러므로 센서 네트워크의 평가를 위해서 정확한 에너지 모델이 필요하다. 본 논문에서는 센서 네트워크의 전력 소모를 분석한다. 전력 소모 모델을 개발하기 위해서 TelosB를 기반으로 하는 상용 제품인 Kmote의 전력 특성을 측정한다. 제안한 모델로부터 PIR 센서를 이용하는 인체 감지 응용에서 건전지를 사용하는 센서 노드는 약 6.9개월의 수명을 예상할 수 있다. 이러한 결과를 바탕으로 독거노인 모니터링 시스템에 적용 가능함을 확인하였다.

• 한국물환경학회지
• /
• 제21권6호
• /
• pp.682-686
• /
• 2005

Recently some urban areas have been flooded due to heavy storm rainfalls. Though major causes of these floodings may be attributed to localized heavy rainfalls, other factors are related to urban flooding including deficiency of storm sewer network capacity, change of surface runoff due to covered open channels, and operational problems of storm drainage pump stations. In this study, hydrologic and hydraulic analysis of Sutak basin in Guri city were carried out to evaluate flooding problems occurred during the heavy storm in July, 2001. ArcView, a world most widely used GIS tool, was used to extract required data for the hydrologic analysis including basin characteristics data, concentration times, channel routing data, land use data, soil distribution data and SCS runoff curve number generation from digital maps. HEC-HMS, a GIS-based runoff simulation model, was successfully used to simulate the flood inflow hydrograph to Sutak pumping station.

• 상하수도학회지
• /
• 제26권4호
• /
• pp.555-563
• /
• 2012

Due to the importance of energy-saving and CO2 reduction is being emphasized in the world, efforts to find a solution for the problems is increasing rapidly. In particular, the renewable energy is on understanding as a breakthrough for the protection of the environment and the economic development, so it is intensively fostered as future industries. Developed countries are already pursuing policy and technology development related with renewable energy. In this paper, we will develop MHD(Magneto Hydro Dynamics) technology to supply the commercial power that can is targeted at water pipe related with hydro power among renewable energy technologies. Kinetic energy of fluid flowing in the water pipe is converted into electric power. It allows stable power supply to the various sensors and devices on water pipe. We have performed several experiments to verify the application possibility of the developed technologies and present the result and a method of performance improvement of the technologies.

• 한국과학교육학회지
• /
• 제13권3호
• /
• pp.327-333
• /
• 1993

The purpose of this study was to investigate children's ideas about growth of plants and their conceptural change after instruction to apply SPACE (Science Processes And Concepts Exploration) Learning strategy. For this study, a total of 55 students from infants to 5th grade were sampled. Data were obtained by the individual interview procedure and summarized by using network analysis. The major results of this study were as follows : 1. A very small number of students responded reforming or reorganisation of materials about the mechanism of germination and growth inside the seeds. 2. Almost all students confused between conditions necessary for germination and growth. Water and sunlight were mentioned by many students, while air and temperature were mentioned by a few students as the condition. 3. Some of the students showed that growth occurs continuously. Many students explaned occurence of growth about Plants related to the night, monning, or evening. 4. With the explaning about the necessary conditions for caterpillar growth, students mentioned conditions related in terms of human experience. 5. Many young childrens showed tendency of the egocentric and human-centered view of the world. Students scientific concepts increased significantly with age. Many students conceptions depend on the context-specificity ideas.