• Environmental and Resource Economics Review
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• v.25 no.2
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• pp.321-349
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• 2016

According to the recent observation by NOAA(US National Oceanic and Atmospheric Administration), 2015 is the warmest year based on global average temperature since 1880. The air temperatures in the Arctic have been rising at almost twice the global average and the extent and thickness of sea ice in the Arctic have declined. And the warming process in the Arctic is accelerating rapidly. These impacts of drastic change in sea ice caused by climate change in the Arctic threaten the eco-system service and biodiversity in the Arctic. This study intends to estimate the economic value on changes in eco-system services and biodiversity of the Arctic caused by climate change. The result of the valuation indicates that the total benefit from improvement of ecosystem in the Arctic ranges from 318.6 billion won to 715.9 billion won per annum. Replication scenarios can be explored into two broad categories in future studies: scenarios in consideration of conflicts of different stakeholders and scenarios based on wider or narrower definition of biodiversity in the Arctic.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.531-537
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• 1999

The present study was carried out to investigate the pathogenicity and pathogenesis of wild rats(Rattus norvegicus), trapped in nature, intranasally infected with Aujeszky's disease virus(ADV/NYJ-1-87) by histopathology, immunohistochemistry and in situ hybridization(ISH). Fifteen rats inoculated intranasally were roughened haircoat, anorexia, listlessness, and depression second day after inoculation, and three rats died in 66-72 hours. Eight rats showed severe pruritus at the face that was accompanied by frequent face-washing movements of the forelegs, and then became violent and spasmodic for an hour or until they died. Four rats slowly recovered after showing mild clinical signs of the disease. Microscopic lesions in infected rats were characterized by meningitis, perivascular round cell infiltration, focal gliosis, and neuronal degeneration and necrosis. And intranuclear inclusion bodies were frequently detected in the cerebral cortex and medulla. Positive reaction to ADV by immunohistochemistry and ISH were detected in the following areas : trigermimal ganglion, brain, tonsil, nasal mucosa, spleen, lung and liver. The result has suggested that ADV intranasally infected in wild rats is followed by replication in epithelial calls of nasal mucosa and tonsil, then invade local lymph nodes by way of the lymphatics. It is also believed that the virus invades bipolar olfactory cells and trigerminal ganglion; and then spread into central nervous system.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.991-998
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• 2003

There are many methods to enhance the fault tolerance of the CORBA based real time systems by viewpoints. Among them, this paper provides a method to enable seamless services where the systems based on the CORBA have object's faults originated processing real time information. Namely, this paper observes a method to deal efficiently with object's faults happening in 3 tier architecture environments. It is possible to replicate objects as a way to enhance the fault tolerance considering object's faults. Along with it, this paper shows a method to enhance the fault tolerance ultimately and then keep the service continuity by prividing a way to allow to continue to run the systems until the FT-CORBA based one's faults are recovered.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.1-12
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• 2014

Recently, the need for non-stop service is increasing by the business mission-critical Internet banking, e-payment, e-commerce, home shopping, securities trading, and petition business increases, clustered in a single database of existing, redundant research on high-availability technologies related to technique, etc. is increasing. It provides an API based on the Active Log in addition to the technique of redundancy, ALTIBASE$^{TM}$ Log Analyzer (below, ALA), provides scalability and communication of the same model or between heterogeneous. In this paper, we evaluated the performance of ALA by presenting the design of the database system that you can use the ALA, to satisfy all the synchronization features high scalability and high availability, real-time.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.4
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• pp.247-258
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• 2009

Distributed file systems running on a cluster of inexpensive commodity hardware are being recognized as an effective solution to support the explosive growth of storage demand in large-scale Internet service companies. This paper presents the design and implementation of BeanFS, a distributed file system for large-scale e-mail services. BeanFS is adapted to e-mail services as follows. First, the volume-based replication scheme alleviates the metadata management overhead of the central metadata server in dealing with a very large number of small files. Second, BeanFS employs a light-weighted consistency maintenance protocol tailored to simple access patterns of e-mail message. Third, transient and permanent failures are treated separately and recovering from transient failures is done quickly and has less overhead.

• Journal of Software Assessment and Valuation
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• v.17 no.2
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• pp.91-99
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• 2021

In the current business environment where dependence on IT has increased rapidly, the risk from disasters or cyber-attacks is also increasing. Business continuity, the ability to continue to provide service in the event of a business disruption caused by a disaster, is essential. In other words, you need to have a plan in place to keep your core business functions uninterrupted with rapid recovery within a predetermined Recovery Time Objective (RTO) and Recovery Point Objective (RPO) time frame. In this paper, we propose a disaster recovery system construction method that can minimize RTO and RPO to ensure business continuity. The system configuration adopts Tier 7 disaster recovery model, synchronous storage replication, hot disaster recovery site, and operation management automation solution. This ensures continuity of core business with virtually no data loss and minimal RTO and RPO.

• Korean Journal of Cognitive Science
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• v.23 no.1
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• pp.73-95
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• 2012

Two experiments were conducted to verify how the factors of attentional dispersion, reason for waiting, and cue of time flow affect the perceived waiting time. In experiment 1, based on the characteristics of waiting experience that Maister(1985) suggested, levels of attentional dispersion and whether or not offering a reason for waiting were manipulated. Participants estimated elapsed time(the objective time was 10 minutes) using either prospective or retrospective estimation method. Overall results were that they overestimated the elapsed time regardless of the experimental conditions. However, both main effects of the attentional dispersion and the reason for waiting were statistically significant. That is, when attention was more dispersed and when the reason was given, overestimation of elapsed time was reduced. No difference was found between the two estimation methods, and none of the interaction was significant. Experiment 2 was a replication of Experiment 1 except that a cue of time flow was added by using scroll bar on a computer screen. Because it has been suggested that the cue can help us to manage the waiting time and result in differences between the two time estimation methods. The results showed that main effects of the attentional dispersion and the reason for waiting were significant as those in Experiment 1. In addition, main effect of time estimation method and the three-way interaction were also significant. None of two-way interaction was significant. That is, the perceived waiting time is much shorter in the retrospective method, and the effects of the attentional dispersion and the reason of waiting were dependent upon the estimation methods. Both experiments showed that offering a clear reason for waiting is more important than the attentional dispersion in reducing the perceived waiting time. Some implications of these results for the service industry and the future direction of research were discussed in the final section.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.2
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• pp.267-277
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• 2017

One of fundamental problems in developing robust distributed services is how to achieve distributed consensus agreeing some data values that should be shared among participants in a distributed service. As one of algorithms for distributed consensus, Raft is known as a simple and understandable algorithm by decomposing the distributed consensus problem into three subproblems(leader election, log replication and safety). But, the algorithm dose not mention any types of dynamic configuration of participant peers such as adding new peers to a consensus group or deleting peers from the group. In this paper, we present a new consensus algorithm named Raft-D, which supports the dynamic configuration of participant peers by extending the Raft algorithm. For this, Raft-D manages the additional information maintained by participant nodes, and provides a technique to check the connection status of the nodes belonging to the consensus group. Based on the technique, Raft-D defines conditions and states to deal with adding new peers to the consensus group or deleting peers from the group. Based on those conditions and states, Raft-D performs the dynamic configuration process for a consensus group through the log update mechanism of the Raft algorithm.