• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.10
• /
• pp.799-807
• /
• 2002

The vibration signal can give an indication of the condition of rotating machinery, highlighting potential faults such as unbalance, misalignment and bearing defects. The features in the vibration signal provide an important source of information for the faults diagnosis of rotating machinery. When additional training data become available after the initial training is completed, the conventional neural networks (NNs) must be retrained by applying total data including additional training data. This paper proposes the fault diagnostics algorithm using the ART-Kohonen network which does not destroy the initial training and can adapt additional training data that is suitable for the classification of machine condition. The results of the experiments confirm that the proposed algorithm performs better than other NNs as the self-organizing feature maps (SOFM) , learning vector quantization (LYQ) and radial basis function (RBF) NNs with respect to classification quality. The classification success rate for the ART-Kohonen network was 94 o/o and for the SOFM, LYQ and RBF network were 93 %, 93 % and 89 % respectively.

• Journal of Communications and Networks
• /
• v.11 no.4
• /
• pp.416-427
• /
• 2009

Domain name system (DNS) is a primary identification mechanism for Internet applications. However, DNS resolutions often take an unbearably long time, and this could seriously impair the consistency of the service quality of Internet applications based on DNS such as World Wide Web. Several approaches reduce DNS resolution time by proactively refreshing expired cached records or prefetching available records beforehand, but these approaches have an inherent problem in that they cause additional DNS traffic. In this paper, we propose a DNS resolution time reduction scheme, named renewal using piggyback (RUP), which refreshes expired cached records by piggybacking them onto solicited DNS queries instead of by issuing additional DNS queries. This method decreases both DNS resolution time and DNS traffic since it reduces the number of queries generated to handle a given DNS resolution without generating additional DNS messages. Simulation results based on two large independent DNS traces show that our proposed approach much reduces not only the DNS resolution time but also the DNS traffic.

• Journal of Internet Computing and Services
• /
• v.16 no.5
• /
• pp.39-47
• /
• 2015

The centrality is calculated to describe the importance of a node in a graph and ranking is given according to the centrality for each node. There are many centrality measures and we use degree centrality, closeness centrality, eigenvector centrality, and betweenness centrality. In this paper, we analyze the effect of an additional edge of a graph on centrality and ranking through experimental computations. It is found that the effect of an additional edge on centrality and ranking of the nodes in the graph is different according to the graph structure using PCA. The results can be used for define the graph characteristics.

• The Korean Journal of Emergency Medical Services
• /
• v.13 no.1
• /
• pp.61-72
• /
• 2009

Purpose : This study was conducted to understand the unforeseen phone calls placed through the 1339 emergency medical communication system by residents of the Gwangju/Jeonnam area during the Lunar New Year and Chuseok holidays. Methods : A descriptive research method was implemented using SPSS to analyze 9,047 reported and received consultation phone calls made during the 2008 Lunar New Year holiday (February 6-10) and the 2008 Chuseok holiday (September 13-15) for frequency and percentages. Results : Among the general characteristics of subjects during the Lunar New Year and Chuseok holidays, an examination of the distribution for gender showed more men than women and the distribution for age showed most subjects were thirties, followed by forties, and finally under ten years of age. According to the status of situational calls during the Lunar New Year holiday most were used for in the following order : providing resource information, misdialing and prank calls, and additional consultations. According to the status of situational calls during the Chuseok holiday most were used for in the following order : providing resource information, additional consultations, misdialing and prank calls. According to region most came from Gwangju Metropolitan City Bukgu, followed by Yeosu, Suncheon, and Mokpo in Jeonnam. According to callers, the majority were non-medical persons. According to time most were made between 9:01 and 12:00, while the fewest were made during 3:01 and 6:00. According to treatment department most were made in the following order : internal medicine, pharmacy, and pediatrics. Most medical resource information provided regarded areas outside the callers location. Conclusion : Emergency medical technician will play a central role in the emergency medical information system in the near future.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.1
• /
• pp.115-128
• /
• 2017

The methods of electronic financial fraud continue to evolve. Various research and countermeasures have been proposed to counter this problem, but it is difficult to eradicate it. The purpose of this study is to analyze the risk of electronic financial fraud through MS Threat Risk Modeling and to propose the countermeasures against the electronic financial fraud. As a result of the analysis, it is confirmed that despite the difference of authentication methods, there is a high risk of pharming, and it is difficult to prevent attack by using only additional authentication means, device security or user authentication based security system. Therefore, this study suggests the introduction of preventive measures such as readjustment of transaction limit by security means, account authentication, and additional physical security measures. It also suggests the establishment and implementation of a comprehensive electronic financial fraud prevention policy through linkage of electronic fraud prevention system and improvement of public relations and user awareness.

• Journal of Species Research
• /
• v.9 no.3
• /
• pp.233-246
• /
• 2020

A scientific name is one of changeable terms in biology whenever additional research results of specific taxa is accumulated. The Database of the National Species List of Korea (DBNKo) was developed to manage taxonomic information of Korean species, designed to describe the changeable and complex taxonomical structure and information. A Korean Taxonomical Serial Number (KTSN) was assigned to each taxon, different from the normally used systems that the scientific name was considered as primary key to manage higher rank of taxa systematically. Common names were also treated with the KTSN, reflecting that common name is considered as one type of taxon. Additional taxonomic information (e.g., synonyms, original names, and references) was also added to the database. A web interface with an intuitive dashboard presenting taxonomic hierarchical structure is provided to experts and/or managers of the DBNKo. Currently, several biological databases are available in the National Institute of Biological Resources (NIBR) such as a specimen database, a digital library, a genetic information system, and the shared species data based on the DBNKo. The DBNKo started sharing species information with other institutions such as the Nakdonggang National Institute of Biological Resources. It is an ideal centralized species database to manage standardized information of Korean species.

• The Journal of Society for e-Business Studies
• /
• v.21 no.3
• /
• pp.1-13
• /
• 2016

The many researches on context-aware service based on the combination of semantic technology and IoT environment are being actively done. However, the previous study exploiting ontology has limitations not to accommodate the service requirement changes due to ontology prebuilt by specific service scenario. Although the concept of cross vertical ontology has emerged in order to overcome the limitation, it has other limitations that need additional components composing service environment for expressing context information and can't represent state information of environment elements. To cope with these limitations, we propose SISO (Semantic-based IoT Service Ontology) that can represent the states of environmental element without the need for additional context-information element. To verify SISO's characteristics, we select the service scenario and present applied results. The qualitative analysis comparing with the previous study is also presented by the applied results of service scenario.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.4
• /
• pp.129-136
• /
• 2017

Climate change is the biggest environmental issue of our times. A variety of activities to reduce greenhouse gas emissions have been in progress to observe the Kyoto Protocol. Especially, the Energy Target Scheme is created to reduce greenhouse emission with the supervision of Korean government. This includes Green-house Gas Information Systems to promote activities in the private sector to reduce green-house gas emissions, to cut a cost of energy use, and to reduce GHG emissions. Also, the system has calculated the amount of greenhouse gases. Without any additional investment, 2.75% savings are increased over the previous year. In service sector, a cooperation of customers and employees is necessary. A reduction of GHG emissions requires a proper service organization, considering an amount of investment and payback period. Without any additional investment or replacement, employees can save energy easily turning off ventilation systems an hour before employees' departure, installing timers to turn off water purifiers and vending machines after some period of no use. The Green-house Gas Information System is similar to that of Environmental Management System. However, the Excel is the best program to calculate an amount of green-house gas emissions, and to assess for a reduced amount of GHG emissions. A goal of this research is to propose a practical method in the private sector to calculate an amount of green-house gases. The Green-house gas Information System based on Excel spreadsheet gives standards for good evaluation. The greenhouse gas information system establishes and executes the policies and objectives related to greenhouse gas emissions Similar to ISO 14001 environment management system structures, the advantages of using simplified Excel Sheet for calculating GHG emissions and reducing GHG emissions are easy to access.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.7
• /
• pp.47-55
• /
• 2020

In this paper, we propose one stage multi-scale face detector based Fully Convolution Network using anchor free method. Recently almost all state-of-the-art face detectors which predict location of faces using anchor-based methods rely on pre-defined anchor boxes. However this face detectors need to hyper-parameters and additional computation in training. The key idea of the proposed method is to eliminate hyper-parameters and additional computation using anchor free method. To do this, we apply two ideas. First, by eliminating the pre-defined set of anchor boxes, we avoid the additional computation and hyper-parameters related to anchor boxes. Second, our detector predicts location of faces using multi-feature maps to reduce foreground/background imbalance issue. Through Quantitative evaluation, the performance of the proposed method is evaluated and analyzed. Experimental results on the FDDB dataset demonstrate the effective of our proposed method.

• The Journal of the Korea Contents Association
• /
• v.12 no.9
• /
• pp.16-26
• /
• 2012

A path generation method considering the tendencies of users is required because users has the preferred routes through the properties such as time, distance, and congest. The existing method must input the additional information about user's tendency to generate path considering moving tendencies. However, mobile device have the inconvenient interface. Therefore users are reluctant to input additional information for path generation. In this paper, we propose the path generation method considering the tendencies of users without additional input of users tendencies. To show the superiority of the proposed method, we compared it with shortest distance or time path through performance evaluation.