• Journal of Power System Engineering
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• v.12 no.6
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• pp.18-23
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• 2008

This paper describes development of real-time condition monitoring system to observe state of a container crane in a port. To analyze the state of a crane, the strength and the direction of wind are measured with sensors along with the load resulted a crane at the moment. The measured signals are processed by especially developed conditioning board and converted into digital data. Measured data are analyzed to define the state of the crane at an indicator. For transmission of these data to the indicator, we implemented wireless sensor network based on IEEE 802.15.4 MAC(Media Access Control) protocol and Bluetooth network protocol. To extend the networking distance between the indicator and sensor nodes, the shortest path routing algorithm was applied for WSN(Wireless Sensor Network) networks. The indicator sends the state information of the crane to monitoring server through IEEE 802.11 b wireless LAN(Local Area Network). Monitoring server decides whether alarm should be issued or not. The performance of developed WSN and Bluetooth network were evaluated and analyzed in terms of communication delay and throughput.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.7
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• pp.611-617
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• 2015

In the development of a vibration-based condition monitoring system in gearbox, one of the most important research topics is a quantitative analysis and test of the effect of gear damage on vibration of gearbox. This paper presents the evaluation result of vibration condition indicator according to the gear tooth damage through the vibration test of gearbox. The dynamic load test was performed with high speed railway (KTX)'s gearbox. The vibration of gearbox was measured according to a rotational speed change with the common gear fault modes, such as pitting and tooth breakage. The characteristics and the possibility of applying of vibration condition indicator on condition monitoring system were analyzed. As a result, the value of most condition indicator is gradually increased with the severity of gear faults. The NA6 indicator shows a low variation with the rotational speed change and high sensitivity in accordance with the gear fault.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.125-132
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• 2010

Characterization of sediment quality is important for the proper management of surface water quality, yet sediment has not been monitored sufficiently. In this study, fecal indicator microorganism concentrations of sediments in the Geum River Basin were monitored. Sampling was carried out at one paddy field, one lakeshore and five monitoring stations in the lower reach of the Geum River Basin. Surface waters and sediments were sampled four times during rainy season. Total coliform concentrations of sediments were 12 times higher in average to those of surface waters while E. coli concentrations of sediments were six times higher. No correlation found between indicator microorganism concentration between surface waters and sediments.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.3
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• pp.301-308
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• 2011

International Maritime Organization (IMO) proposed the Energy Efficiency Operation Indicator (EEOI) in 2005 and the Energy Efficiency Design Index (EEDI) in 2008 so as to address emission concern and regulation. Likewise, Ship Energy Efficiency Management Plan (SEEMP) and Greenhouse Gas (GHG) monitoring and management are also becoming an issue lately. This paper introduces the energy efficiency design index (operation indicator) monitoring system (EDiMS) software can continuously monitor $CO_2$, $NO_x$, $SO_x$, and PM values emitted from ship. The accurate inventory of ships GHG can be obtained from base of emission result during the engine shop test trial and the actual monitoring of shaft power and ship speed. In addition, the ability to store all exhaust emission and engine operation data can be applied as the useful tool of the inventory work of air pollution and ship energy management plan for the mitigation or reduction of ship emissions.

• Environmental Analysis Health and Toxicology
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• v.23 no.4
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• pp.231-245
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• 2008

Various methods for detecting changes in response behaviors of indicator specimens are presented for monitoring effects of toxic treatments. The movement patterns of individuals are quantitatively characterized by statistical (i.e., ANOVA, multivariate analysis) and computational (i.e., fractal dimension, Fourier transform) methods. Extraction of information in complex behavioral data is further illustrated by techniques in ecological informatics. Multi-Layer Perceptron and Self-Organizing Map are applied for detection and patterning of response behaviors of indicator specimens. The recent techniques of Wavelet analysis and line detection by Recurrent Self-Organizing Map are additionally discussed as an efficient tool for checking time-series movement data. Behavioral monitoring could be established as new methodology in integrative ecological assessment, tilling the gap between large-scale (e.g., community structure) and small-scale (e.g., molecular response) measurements.

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.119-122
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• 2015

It is very useful and important to see the status and change of necessary parts in a short period through selecting and observing the bioindicator continually to forecast and prepare the future. Especially, living things are so closely related to the environment that the indicator between the environment and living things shows close interrelationship. Also, the indicator related to environment provides information about representative or decisive environmental phenomenon and is used to simplify complicated facts. Considering wide range of background and application including various indicators such as the change-, destruction-, pollution-, and restoration of habitats, climate change, and species diversity, the closest category includes "environmental indicator," "ecological indicator," and "biodiversity indicator." The selection and use of bioindicator is complicated and difficult. The necessary conditions for the indicator selection are flexible and greatly depend on the goals of investigation such as the indicator for biological diversity investigation of specific area, the indicator for habitat destruction, the indicator for climate change, and the indicator for polluted area. It should meet many various conditions to select a good indicator. In this study, eleven selection standards are established based on domestic and overseas studies on bioindicator selection: species with clear classification and ecology, species distributed in geographically widespread area, species that show clear habitat characteristics, species that can provide early warning for a change, species that are easy and economically benefited for the investigation, species that have many independent individual groups and that is not greatly affected by the size of individual groups, species that is thought to represent the response of other species, species that represent the ecology change caused by the pressure of human influence, species for which researches on climate change have been done, species that is easy to observe, appears for a long time and forms a group with many individuals, and species that are important socially, economically, and culturally.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.676-682
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• 2011

Sybil attack can disrupt proper operations of wireless sensor network by forging its sensor node to multiple identities. To protect the sensor network from such an attack, a number of countermeasure methods based on RSSI (Received Signal Strength Indicator) and LQI (Link Quality Indicator) have been proposed. However, previous works on the Sybil attack detection do not consider the fact that Sybil nodes can change their RSSI and LQI strength for their malicious purposes. In this paper, we present a Sybil attack detection method based on a transmission power range. Our proposed method initially measures range of RSSI and LQI from sensor nodes, and then set the minimum, maximum and average RSSI and LQI strength value. After initialization, monitoring nodes request that each sensor node transmits data with different transmission power strengths. If the value measured by monitoring node is out of the range in transmission power strengths, the node is considered as a malicious node.

• Journal of Power Electronics
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• v.11 no.4
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• pp.424-429
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• 2011

In this paper, the simulator of an on-line monitoring system for the range extender electric vehicle has been developed. The messages from the four control modules, the air pressure and fuel level sensors data, and the on/off switching states of 31 indicator lamps can be received through the control area network (CAN), and displayed on the graphic panel. The simulator was designed using the four DSP boards, variable resistors, and toggle switches instead of the four control modules, sensors, and switching state of indicator lamps on an actual series hybrid electric vehicle (SHEV) bus, respectively. The performance of the monitoring technologies was verified with the simulator at the laboratory, and then it was tested on an actual SHEV bus. The simulator is very useful at the initial development of the monitoring system at the hybrid-type or electrical vehicles.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.4
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• pp.213-218
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• 2002

The use of biological indicator for environmental monitoring has suddenly become popular in many international organizations as well as domestic ones. Since the biological indicator species should be well responsive to native environmental change, development of native indicator species is prerequisite for environmental assessment and restoration program. Through regression analysis of mean density and pH, potential indicator species were screened from Namsan and Kwangreung where differential environmental stresses are influenced; Lasiobelba remota, Ceratozetes sp. Tectocepheus velatus, Neogymnobates sp. and Oppia sp.3. Also keystone species in two study area were Lohmannia coreana, Ceratozetes sp., Rostrozetes pulcherrimus, and Lasiobelba remota in Namsan Deciduous forest and Neogymnobates sp., Neogymnobates donghaksaensis, and Cultroribula tridentata in Kwangreung. Advantages and disadvantages of using biological indicator for environmental monitoring were further discussed.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.22-29
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• 2007

Investigation of carabid beetles as on ecological indicator species for wetland characterization and monitoring was conducted in three types of wetlands such as emergent wetland, forested wetland, and estuary, During the investigation period, twenty-eight species belonging to twenty-two genera and three families(Carabidae, Harpalidae, Brachinidae) were identified. The diversity of carabid beetles at riverine wetland such as Woopo (H'=1.18) and Hwapo-neup (H'=1.08) were higher than in the forested wetland (H'=1.03) and estuarine (H'=0.91). Species compositions in each wetland were significantly different(${\chi}^2=1716.8$, P<0.01). Riverine wetlands differed significantly from the forested wetland. Indicator species for the wetland chose with indicator species analysis were reacted sensitively on the parameter such as soil composition, moisture of soil, and environmental change. Thus, it was consequently suggested that these indicator species may be applied for wetland characterization and monitoring of the wetland ecosystem.