• Journal of KIISE:Computer Systems and Theory
• /
• v.31 no.5_6
• /
• pp.371-378
• /
• 2004

This paper presents the implementation and performance of the HVIA-GE card, which is a hardware implementation of the Virtual Interface Architecture (VIA) based on Gigabit Ethernet. The HVIA-GE card is a 32-bit/33MHz PCI adapter containing an FPGA for the VIA protocol engine and a Gigabit Ethernet chip set to construct a high performance physical network. HVIA-GE performs virtual-to-physical address translation, Doorbell, and send/receive completion operations in hardware without kernel intervention. In particular, the Address Translation Table (ATT) is stored on the local memory of the HVIA-GE card, and the VIA protocol engine efficiently controls the address translation process by directly accessing the ATT. As a result, the communication overhead during send/receive transactions is greatly reduced. Our experimental results show the maximum bandwidth of 93.7MB/s and the minimum latency of 11.9${\mu}\textrm{s}$. In terms of minimum latency HVIA-GE performs 4.8 times and 9.9 times faster than M-VIA and TCP/IP, respectively, over Gigabit Ethernet. In addition, the maximum bandwidth of HVIA-GE is 50.4% and 65% higher than M-VIA and TCP/IP respectively.

• Journal of the Korea Society for Simulation
• /
• v.18 no.3
• /
• pp.47-59
• /
• 2009

Due to the application-specific nature of wireless sensor networks, the sensitivity to such a requirement as data reporting latency may vary depending on the type of applications, thus requiring application-specific algorithm and protocol design paradigms which help us to maximize energy conservation and thus the network lifetime. In this paper, we propose a novel delay-adaptive sensor scheduling scheme for energy-saving data gathering which is based on a two phase clustering (TPC). The ultimate goal is to extend the network lifetime by providing sensors with high adaptability to the application-dependent and time-varying delay requirements. The TPC requests sensors to construct two types of links: direct and relay links. The direct links are used for control and forwarding time critical sensed data. On the other hand, the relay links are used only for data forwarding based on the user delay constraints, thus allowing the sensors to opportunistically use the most energy-saving links and forming a multi-hop path. Simulation results demonstrate that cluster-based delay-adaptive data gathering strategy (CD-DGS) saves a significant amount of energy for dense sensor networks by adapting to the user delay constraints.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.6 no.3
• /
• pp.103-109
• /
• 2010

Total performance is improved by minimizing the channel interference between links in wireless mesh networks (WMNs). The paper refines on the CB-CA [1] to be suitable for multi-radio multi-channel (MRMC) WMNs. The CB-CA is the cluster-based channel assignment algorithm for one radio three channel WMN based on IEEE 802.11b/g. The CB-CA does not perform the channel scanning and the channel switching between the cluster heads (CHs) and the edge gateway nodes (EGs). However, the use of co-channel for links between CHs and EGs brings the problem of channel interference among many nodes. We propose and evaluate an improved CB-CA algorithm to solve this problem in MRMC WMNs. The proposed algorithm discriminates between transmission channel and receive channel and assigns channels to each interface randomly and advertises this information to neighbor clusters in order to be assigned no-interference channel between clusters. Therefore, the proposed algorithm can minimize the interference between clusters and also improve QoS, since it can use multiple interfaces and multiple channels.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.5
• /
• pp.880-887
• /
• 2011

The Wireless Mesh Network(WMN) technology is able to provide an infrastructure for isolated islands, in which it is difficult to install cables or wide area such as battlefield. Therefore, WMN is frequently used to satisfy needs for internet connection and active studies and research on them are in progress. However, as a result of increase in number of hops under hop-by-hop communication environment has caused a significant decrease in throughput and an increase in delay. Considering the heavy traffic of real-time data, such as voice or moving pictures to adaptive WMN, in a military environment. Such phenomenon might cause an issue in fairness index. In order to resolve this issue, we proposed a Cluster Based Multi-channel Assignment Scheme(CB-MAS) for adaptive tactical wireless mesh network. In the CB-MAS, the communication between the Cluster-Head(CH) and cluster number nodes uses a channel has no effect on channels being used by the inter-CH links. Therefore, the CB-MAS can minimize the interference within multi-channel environments. Our Simulation results showed that CB-MAS achieves improved the throughput and fairness index in WMN.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.323-325
• /
• 2012

본 논문에서는 거리정보에 기반을 두지 않은 방식(range-free)에서 라우팅 에너지 효율성을 고려한 ALPS(Ad hoc network Localized Positioning System) 알고리즘을 제안한다. 관련하여 기존의 대표적인 관련 연구로는 DV-Hop 알고리즘이 있다. 이는 앵커 노드와 앵커 노드사이의 미지 노드들의 거리를 홉 수로 나누어 노드 사이의 거리를 구하고 삼각측량법을 이용하여 노드의 좌표를 계산한다. 하지만 이 경우 앵커 노드와 미지노드 사이의 거리를 홉 수로 나눈 한 홉 거리가 모두 동일하다고 가정하였고, 이에 사용되는 앵커노드간의 평균 거리를 사용하여 노드간의 거리정보를 구하게 되어 각 중계노드는 고정된 경로에서만 거리 정보를 알 수 있다. 본 논문에서 제안되는 ALPS 알고리즘은 계층적 클러스터 단위에 소속된 임의의 노드에 대한 위치정보를 제공하는 방법을 제안한다. 제안된 알고리즘에 따른 위치정보를 사용 할 경우 기존의 DV-hop방식에 따른 노드의 위치정보를 사용한 경우보다 보다 최적화된 에너지 소모를 유지할 수 있는 경로 알고리즘을 최종적으로 제공하는데 연구의 목적이 있다. 본 논문에서는 상기 두 가지 방식의 위치정보에 따른 라우팅에서 소모되는 에너지 관계를 비교하여 보다 최적화된 에너지 경로 알고리즘이 제공되는 결과를 검증하고 보여주고자 한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2016.10a
• /
• pp.149-150
• /
• 2016

모바일 컴퓨팅의 발전은 모바일 디바이스에게 클라우드 컴퓨팅 기술 도입을 가져왔다. 모바일 클라우드 컴퓨팅은 워크스테이션 및 클러스터로 구축된 클라우드 컴퓨팅과 다르게 모바일 디바이스만을 가지고 자원 서비스를 제공한다. 모바일 클라우드는 모바일 디바이스의 저조한 하드웨어 성능과 산발적인 네트워크 연결을 가진다. 모바일 클라우드의 인프라 구성을 위해서는 모바일 디바이스의 연결 및 자원 통합이 매우 중요시 된다. 본 논문에서는 모바일 클라우드 컴퓨팅의 인프라 구축을 위해 연결된 모바일 디바이스의 자원 통합 및 지속적인 자원 서비스 관리를 제공하는 M-RIM(Mobile device - Resource Integration Management)을 제안한다. M-RIM은 모바일 디바이스의 성능 정보 메타데이터 기반 분산 자원을 통합하고 사용자에게 자원 서비스를 제공한다.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.11
• /
• pp.91-96
• /
• 2014

Since the sensors of Internet of Things (IOT) collect various data, the lifetime of sensor network is very important and the data should be aggregated efficiently. The contiguous collection by the certain sensors occurs an excessive battery consumption and successive transmission of same value of data should be avoided. To solve these things, we propose an weight-based cluster head replacement method that divides whole network into several grids and cluster head is selected by remaining energy, density of alive sensors and location of sensor. The aim of algorithm maximizes the lifetime of network. Our simulation results shows that the proposed method is very simple as well as balances energy consumption.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.2
• /
• pp.103-109
• /
• 2019

Due to the development of ICT technology, the IoT environment for connecting objects in the vicinity to networks and utilizing information about objects in various fields is getting attention, and security threats are also increasing. In order to solve the increasing security problem in IoT environment, we are studying methods that use certificate, encryption, hash calculation and block chain in the private sector. However, the security authentication method which overcomes the performance gap between devices and has compatibility with various devices It has not been proposed yet. In this paper, we propose an authentication method that can achieve wide compatibility by minimizing the influence of IoT device environment.

• Journal of the Korean Society for Library and Information Science
• /
• v.58 no.1
• /
• pp.395-415
• /
• 2024

In the development of a university library's collection, the concept of patron-driven acquisition refers to a collection strategy that addresses users' direct information needs. In this study, an analysis of ten years' worth of book requests by user types was conducted to understand the topic preferences for efficient collection devleopment in the university library. In collection development, identifying subject areas of users' requested books is necessary for librarians to identify key areas of collection development and establish balanced collection development policies. To identify the major subject areas for each user group, KDC (Korean Decimal Classification) subject classifications were used, and network analysis techniques were applied to investigate the relationships between book topics in detail. The analysis revealed that "social sciences" emerged as the major topic across all user groups. However, in the analysis of sub-topics, "medicine" and "psychology" were distinctively identified as the major subject areas for graduate students, setting them apart from other user groups. The result of the network analysis further indicated that undergraduate students showed unique topics such as civil service, job placement, and career, which were not observed as major topic clusters in other user groups. On the other hand, graduate students tended to concentrate on a few specialized subjects, forming distinct topic clusters in the analysis.

• Informatization Policy
• /
• v.23 no.2
• /
• pp.73-97
• /
• 2016

Social changes due to ICT like Big Data, IoT, Cloud and Mobile is progressing rapidly. Now, we get out of the old-fashioned frame was measured at the level of the information society through the introduction of PC, Internet speed and Internet subscribers etc and there is a need for a new type of diagnostic information society framework. This study is the study for the framework established to diagnose and measure post-information society. The framework and indicators were chosen in accordance with the technological society coevolution theory and information society-related indicators presented from authoritative international organizations. Empirical results utilizing the indicators and framework developed in this study were as follows: First, the three sectors, six clusters (items), 25 nodes (indicators) that make up the information society showed that all strongly connected. Second, it was diagnosed as information society development (50.34%), technology-based expansion (25.03%) and ICT effect (24.63%) through a network analysis (ANP) for the measurement of importance of the information society. Third, the result of calculating the relative importance of the cluster and nodes showed us (1)social development potential (26.04%), (2)competitiveness (15.9%), (3)ICT literacy (15.5%) (4) (social)capital (24.3 %), (5)ICT acceptance(9.54%), (6)quality of life(8.7%). Consequently, We should take into account the effect of the economy and quality of life beyond ICT infrastructure-centric when we measure the post-information society. By applying the weighting we should performs a comparison between countries and we should diagnose the level of Korea and provide policy implications for the preparation of post-information society.