• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.2
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• pp.135-145
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• 2002

Active networks represent a new approach to network architecture. Nodes(routers, switches, etc.) can perform computations on user data, while packets can carry programs to be executed on nodes and potentially change the state of them. While active networks provide a flexible network iufrastructure, they are more complex than traditional networks and raise considerable security problems. Nodes are Public resources and are essential to the proper and contract running of many important systems. Therefore, security requirements placed upon the computational environment where the code of packets will be executed must be very strict. Trends of research for active network security are divided into two categories: securing active nodes and securing active packets. For example, packet authentication or monitoring/control methods are for securing active node, but some cryptographic techniques are for the latter. This paper is for transferring active packets securely between active nodes. We propose a new method that can transfer active packets to neighboring active nodes securely, and execute executable code included in those packets in each active node. We use both public key cryptosystem and symmetric key cryptosystem in our scheme

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.67-74
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• 2011

In this paper, we presented a dynamic cyber attack tree which can describe an attack scenario flexibly for an active cyber attack model could be detected complex and transformed attack method. An attack tree provides a formal and methodical route of describing the security safeguard on varying attacks against network system. The existent attack tree can describe attack scenario as using vertex, edge and composition. But an attack tree has the limitations to express complex and new attack due to the restriction of attack tree's attributes. We solved the limitations of the existent attack tree as adding an threat occurrence probability and 2 components of composition in the attributes. Firstly, we improved the flexibility to describe complex and transformed attack method, and reduced the ambiguity of attack sequence, as reinforcing composition. And we can identify the risk level of attack at each attack phase from child node to parent node as adding an threat occurrence probability.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2852-2858
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• 2022

A proton therapy facility is under development at Huazhong University of Science and Technology (HUST). To meet the need for fast energy changes during treatments, a beamline control system (BCS) has been designed and implemented. The BCS coordinates and controls various beamline devices by adopting a distributed architecture divided into three layers: the client, server, and device layers. Among these, the design of the server layer is the key to realize fast energy changes. The server layer adopts the submodule programming paradigm and optimizes the data interface among modules, allowing the main workflow to be separated from the device workflow and data. Furthermore, this layer uses asynchronous, multithreaded, and thread-locking methods to improve the system's ability to operation efficiently and securely. Notably, to evaluate the changing energy status over time, a dynamic node update method is adopted, which can dynamically adjust the update frequency of variable nodes. This method not only meets the demand for fast updates on energy changes but also reduces the server's communication load in the steady state. This method is tested on a virtual platform, and the results are as expected.

• The Transactions of the Korea Information Processing Society
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• v.4 no.9
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• pp.2221-2234
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• 1997

Distributed mutual exclusion algorithms have employed two approaches to achieve mutual exclusion and can be divided into two broad classes:token-based and permission-based. Token-based algorithms share a unique token among the nodes and a node is allowed to access its common resources if it possesses the token. Permission-based algorithms require one or more successive rounds of message exchanges among the nodes to obtain the permission to access the common resources. A hypercube architecture has earned wide acceptance in multiprocessor systems in the past few years because of its simple, yet rich topology. Accordingly, we study distributed permission-based mutual exclusion algorithms for hypercubes, and design a distributed permission-based mutual exclusion algorithm based on a new information structure adapted to the hypercubes. The new information structure is a request set of T-pattern from a logical mesh that is embedded into a hypercube. If a node wants to access the common resources, it sends request message to all nodes in the request set by Lan's multicast algorithm. Once the node receives a grant message from all nodes in the request set, it accesses the common resource. We evaluate our algorithm with respect to minimum round-trip delay, blocking delay, and the number of messages per access to the common resource.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.55-67
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• 2014

The historic cultural landscape of East lake in Kyung river area during Joseon dynasty was very outstanding that it had many attractions of scenic beauty, however, the Han river of today is being recognized as a natural landscape and as a place with low cultural and historical traits. This study applied landscape characteristics of the cultural space of Joseon Dynasty on visual image elements of Lynch to research the landscape characteristics. The research results are as follows. When East lake was applied to visual image elements, it was recognized as a 'superb' 'paths,' and the 'edge' which signifies the boundary showed its 'superb' clarity of the East lake. For the 'node,' a turning point of direction, Dumopo represented the 'superb' awareness. As East lake, Apgujung, and Jecheonjung represented the 'superb' awareness when 'landmark' among visual image elements of Lynch was applied to the cultural space, the awareness level and reputation were proportional to the visual image elements. When pattern, structure, and meaning of the cultural space were clear and had definite identity, the 'landmark' and 'district' elements were 'superb.' It was also identified that when awareness level of space was higher, the awareness of historic cultural landscape was high as well. Therefore, considering visual awareness level of the historic cultural landscape of Han river during restoration to investigate and to conduct case studies is considered to increase the awareness level of historicity and cultural character as well as restoration of the place.

• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.151-164
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• 2009

The importance of sensor networks as a base of ubiquitous computing realization is being highlighted, and espicially the security is recognized as an important research isuue, because of their characteristics.Several efforts are underway to provide security services in sensor networks, but most of them are preventive approaches based on cryptography. However, sensor nodes are extremely vulnerable to capture or key compromise. To ensure the security of the network, it is critical to develop security Intrusion Detection System (IDS) that can survive malicious attacks from "insiders" who have access to keying materials or the full control of some nodes, taking their charateristics into consideration. In this perper, we design a distributed and adaptive IDS architecture on sensor networks, respecting both of energy efficiency and IDS efficiency. Utilizing a modified HEED algorithm, a clustering algorithm, distributed IDS nodes (dIDS) are selected according to node's residual energy and degree. Then the monitoring results of dIDSswith detection codes are transferred to dIDSs in next round, in order to perform consecutive and integrated IDS process and urgent report are sent through high priority messages. With the simulation we show that the superiorities of our architecture in the the efficiency, overhead, and detection capability view, in comparison with a recent existent research, adaptive IDS.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.1
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• pp.91-99
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• 2007

The research was carried out to define the morphological and growth characteristics of Poa pratensis L. (Kentucky bluegrass) 'Pureundul' native to Korea. Poa pratensis 'Pureundul' was collected from the belt highway around Mt. Uam located in Naedeok-dong, Cheongju City, Chungcheongbuk-do Province on May 5, 1995. The morphological characteristics of 'Pureundul' were compared with those of 205 individuals of native Poa pratensis collected throughout the nation from June 11, 2000 to June 21, 2003. The findings were as follows : The height of plant was 28.2cm but increased to 40.0cm at the flowering time. The height of first node from the base was 6.8cm and the length and width of leaf were 17.3cm and 2.9mm, respectively. The length of a spike was 7.9cm. Based on these morphological characteristics, 'Pureundul' was defined medium type Kentucky bluegrass. Visual quality(1~9), visual color and visual density were measured. The visual quality, color and density of 'Pureundul' were not superior to those of introduced species but above the average other native species. The damages from the diseases during summer resulted in poorer visual quality of color of 'Pureundul'. But the spread of the diseases was slower in 'Pureundul' than other native species, and accordingly 'Pureundul' didn't suffer from more quality deterioration from July to September during which the diseases broke out. Entering fall, 'Pureundul' showed high quality comparable to that of the introduced species. If 'Pureundul' is put to breeding by implementing pest control in summer and introducing disease tolerant genes, it will be used to make greens of greater quality than now.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1697-1706
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• 1996

This paper presents the design and the implementation of a MissCW(Multi user Interactive System for Synchronous Collaborative Writing). The document model DMDA(Distributed Multimedia Document Architecture) of MissCW consists of the logical structure, presentation style object, and mark object. The windows. The collaborative editor of this system proposes a structure oriented editing mechanism to combine distrbuted objects into one document. The middleware SOM(Shared Object Manager) maintains shared objects consistently and helps application programs use objects efficiently. The infrastructure of this system is a hybrid structure of replicated and centralized architectures, that is to maintain shared objects consistently inside of SOM and to reduce the overhead of network traffic. The central part is a virtual node which corresponds to the Object Controller of SOMwith the SOT(Shared Objet Table).

• Journal of Korea Multimedia Society
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• v.17 no.2
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• pp.226-231
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• 2014

Because of development of information communication and multimedia technology, the focus of M2M(Machine to Machine) intelligent network, multimedia collaboration environment, and transportation safety service is increased. This paper describes a multimedia replicated architecture based on Shepherd environment for transportation safety service. The relationship of information collection and utility is relationship of man to man, but is developed object to object by information communication and control system. This paper suggests a design of multimedia cyber collaboration environment based on M2M. This structure can make multimedia collaboration environment and fault tolerance, so on easily. Because M2M system does not affected to all system in spite of occurring to fault to a node or resource, it has a good condition for design of transportation safety service running on M2M.

• Journal of Information Technology and Architecture
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• v.11 no.4
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• pp.471-483
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• 2014

The purpose of this study was to look over the sharing and flow of information on tourism tourist destination made through social media by utilizing social network analysis. In this research for compared the exchange and diffusion relationships and made information sharing among users of the network group for the Seoul / Busan Tourism Twitter. The first part of analysis dealt with the network centralization and information dissemination patterns from a global perspective. The second part was an analysis of nodes with the highest degree centrality in order to identify the most influential user within the Twitter network and determine the information flow and user characteristics with respect to the information dissemination pattern in Seoul/Busan tourism Twitter. The results scientific evidence was presented that social media users' information search behavior information to understand the sharing and spreading patterns, social media as a marketing tool, simple products and services that will ultimately provide the desired information detainee information is not a means of promoting utilization was presented.