• Journal of Environmental Health Sciences
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• v.31 no.3
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• pp.199-206
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• 2005

C. neoformans-associated cryptococcosis is primarily a disease of immunocompromised persons, has a world-wide distribution, and is often spread by pigeons in the urban environment. In contrast, C. gattii causes infection in normal hosts, has only been described in tropical and semi-tropical areas of the world, and has a unique niche in river gum Eucalyptus trees. Cryptococcosis is acquired through inhalation of the yeast propagules from the environment. C. gattii has been identified as the cause of an emerging infectious disease centered on Vancouver Island, British Columbia, Canada. No cases of C. gattii-disease were diagnosed prior to 1999; the current incidence rate is 36 cases per million population. A search was initiated in 2001 to find the ecological niche of this basidiomycetous yeast. C. gattii was found in the environment in treed areas of Vancouver Island. The highest percentage of colonized-tree clusters were found around central Vancouver Island, with decreasing rates of colonization to the north and south. Climate, soil and vegetation cover of this area, called the Coastal Douglas fir biogeoclimatic zone, is unique to British Columbia and Canada. The concentration of airborne C. gattii was highest in the dry summer months, and lowest during late fall, winter, and early spring, months which have heavy rainfall. The study of the emerging colonization of this organism and subsequent cases of environmentally acquired disease will be informative in planning public health management of new routes of exposure to exotic agents in areas impacted by changing climate and land use patterns.

• Convergence Security Journal
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• v.3 no.2
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• pp.1-10
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• 2003

In the distributed-computing environment, applications or users have to share resources and communicate with each other in order to perform their jobs more efficiently. In this case, it is important to keep resources and information integrity from the unexpected use by the unauthorized user. Therefore, there is a steady increase in need for a reasonable way to authentication and access control of distributed-shared resources. In RBAC, there are role hierarchies in which a higher case role can perform permissions of a lower case role. No vise versa. Actually, however, it is necessary for a lower case role to perform a higher case role's permission, which is not allowed to a lower case role basically. In this paper, we will propose a permission delegation method, which is a permission delegation server, and a permission delegation protocols with the secret key system. As the result of a permission delegation, junior roles can perform senior role's permissions or senior role itself on the exceptional condition in a dedicated interval.

• Korean Journal of Adult Nursing
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• v.18 no.2
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• pp.240-250
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• 2006

Purpose: This study examined the effects of spirituality promoting intervention for the stomach and colon cancer patients. Method: A quasi- experimental design was used. Data collection was carried out from April 2004 to June, 2004 at a cancer center in Korea. The intervention included pray, meditation, group education and discussion for coping with cancer. The experimental group were received a 1-hour intervention per week for 6 weeks, while the control group received usual care. Data collection was done at pre and post intervention. The degree of spirituality was measured by the Korean version of WHOQOL-SRPB pilot test(WHO Quality of Life-Spirituality, Religiousness and Personal Beliefs pilot test) Module, and social support was measured using scores on a PRQ 85(Personal Resources Questionnaire). Fighting spirit was measured by the scores of MAC(Mental Adjustment to Cancer) scale. Results: The experimental group showed significant increase in the scores of social support and fighting spirit compared to those in the control group after the intervention. There were no significant changes in terms of the spirituality score compared to the baseline score in the experimental group and the control group. Conclusion: This intervention appeared to be effective in increasing social support and fighting spirit, which considered to be very helpful in cancer adjustment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.3
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• pp.3-12
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• 2004

Secure operating system is a special operating system that integrates some security functions(i.e. access control, user authentication, audit-trail and etc.) with normal operating system in order to protect system from various attacks. But it doesn't consider my security of network traffic. To guarantee the security of the whole system, network traffic must be protected by a certain way and IPsec is a representative technology for network security. However, it requires administrator's carefulness in managing security policies and the key management mechanism is very heavy as well as complicated. Moreover, it doesn't have a suitable framework for delivery of security information for access control mechanism. So we propose a simple trusted channel mechanism for secure communication between secure operating systems. It provides confidentiality md authentication for network traffic and ability to deliver security information. It is implemented at the kernellevel of IP layer and the simplicity of the mechanism can minimize the overhead of trusted channel processing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.2
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• pp.239-250
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• 2022

LoRa is a physical layer technology designed to secure highly reliable long-range communication with introducing loco parentis tree network and chirp spreading spectrum. Since since a leaf can send message to more than one parents simultaneously with a single transmission in a region, packet delivery ratio increases logarithmically as the number of gateways increases. The delivery ratio, however, dramatically collapses even under loco parentis tree topology due to the limitations of ALOHA-like primitive MAC, . The proposed method is intended to exploit SDMA approach to reuse frequency in an area. With the view, TxPower of each sender for each message in a concurrent transmission is elaborately controlled to survive the collision at different gateway. Thus, the gain from the capture effect improves the capacity of resource-hungry Low Power and Wide Area Networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.10
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• pp.2509-2528
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• 2012

Time division multiple access (TDMA) is a widely used media access control (MAC) technique that can provide collision-free and reliable communications, save energy and bound the delay of packets. In TDMA, energy saving is usually achieved by switching the nodes' radio off when such nodes are not engaged. However, the frequent switching of the radio's state not only wastes energy, but also increases end-to-end delay. To achieve high energy efficiency and low delay, as well as to further minimize the number of time slots, a multi-objective TDMA scheduling problem for industrial wireless mesh networks is presented. A hybrid algorithm that combines genetic algorithm (GA) and simulated annealing (SA) algorithm is then proposed to solve the TDMA scheduling problem effectively. A number of critical techniques are also adopted to reduce energy consumption and to shorten end-to-end delay further. Simulation results with different kinds of networks demonstrate that the proposed algorithm outperforms traditional scheduling algorithms in terms of addressing the problems of energy consumption and end-to-end delay, thus satisfying the demands of industrial wireless mesh networks.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.10
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• pp.59-68
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• 1993

This paper describes implemation of 'General-purpose ETRI MAP interface module' (GEM) for Mini-MAP network. GEM operates as a Mini-MAP node in our FA system. To communicate between GEM and programmable devices(PD) such as PLC and CNC, serial communication is used. Application programs of a MiNi-MAP host system control and monitor programmable devices via GEM. GEM is implemented and tested on the basis of the MAP 3.0. TBC in the Nini-MAP board performs the function of the MAC sublayer. The LLC sublayer is implemented according to the specification of Class 3 that includes Type 1 and 3. And the MMS services are designed within the scope of implementation class MAP3. All the softwares are implemented under the real-time multitask OS for real-time application of the Mini-MAP and they are loaded into PROMs at the network board of GEM. We tested the LLC functions to make use of a protocol analyzer for the token-passing protocol. Also the MMS conformance test was carried out by exchanging primitives between GEM and a MMS product that had already passed the conformance test. Therefore GEM is proposed as a network tool of Computer Integrated Manufacturing (CIM) to integrate PDs which don't support MAP functions.

• Korean Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.189-202
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• 1996

Complex geometric shapes can be defined simply and efficiently by combining and operating various surface primitives. These primitives and their intersection curves are used in finite element mesh generation to form an easy and intuitive procedure for finite element modelling of curved surfaces. This paper proposes techniques of automatic mesh generation on surface primitives with arbitrarily shaped boundaries and control curves, which may be created by surface to surface intersection. A method of automatic mesh generation on plane, which was previously developed by the author, has been modified for application to the surface mesh generation. Owing to the mesh generation-wise differences between planes and surfaces, the surfaces should be transformed into conceptual plane so that the modified plane mesh generation method can be applied. Surface development, mapping and mesh reconstruction are the key techniques suggested in this paper. The selection of the technique to apply can be determined automatically on the basis of the developability, existence of singularity and other characteristics of the surfaces on which the mesh is to be generated. The suggested techniques were implemented into parts of mesh generation functions of the finite element software, MacTran. Their validity and practicality were manifested by the actual use of this software.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.339-342
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• 2005

In order to support ultrawide-band signal generation for low rate WPAN, several types of signal generation mechanisms are suggested such as Chaos, Impluse, and Chirp signals by the activity of IEEE 802.15.4a. The communication system applied chaos theory may have ultrawide-band characteristics with spread spectrum and immunity from multipath effect. In order to use the advantage of chaotic signal generation, we introduce the system implementation of communication and networking systems with the chaos UWB signal. This system may be composed of mainly three parts in hardware architecture : RF transmission with chaotic signal generation, signal receiver using amplifiers and filters, and 8051 & FPGA unit. The most difficult part is to implement the chaotic signal generator and build transceiver with it. The implementation of the system is devidced into two parts i.e. RF blocks and digital blocks with amplifiers, filters, ADC, 8051 processor, and FPGA. In this paper, we introduce the system block diagram for chaotic communications. Mainly the RF block is important for the system to have good performance based on the chaotic signal generator. And the main control board functions for controlling RF blocks, processing Tx and Rx data, and networking in MAC layer.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.2
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• pp.83-88
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• 2000

A Development of a data logger for monitoring wasted water is introduced. A characteristics of the system with microcontroller are simple and cheaper. A portable RAM card is consisted for saving a monitored data. Serial communication is adopted to communicate with a remote monitoring computer. CSMA/CD, which is used widely as MAC(Medium Access Control) in ethernet, is modified to apply a RS485 serial communication. When the measured values run over a limit values, the data logger takes alarm.