• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.615-618
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• 2016

Electrochemical noise(EN) has been used to analyze the deterioration of coating films of offshore wind substructures. In this study, prototype sensors using EN have been developed to detect the corrosion rate. To verify the reliability of sensors, experiments were conducted both in the laboratory and offshore using probe and standard samples. New analysis and data processing techniques show that the sensor can provide useful information about the corrosion rate.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.4
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• pp.314-322
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• 2012

In order to elucidate temporal variations of temperature, salinity, pH, dissolved oxygen (DO), suspended particulate matter (SPM), dissolved inorganic nutrients, and chlorophyll a, we performed 25-hour continuous monitoring in the Seomjin River Estuary in March (dry season) and July (rainy season) 2006. We also investigated spatial variations of marine environmental parameters across a saline gradient. In the Seomjin River Estuary, continuous monitoring results revealed that salinity variations were mainly affected by tidal cycle in the dry season and by river discharge in the rainy season. In the dry season, the spatio-temporal distribution of dissolved inorganic nutrient (nitrate, nitrite, and silicate) concentrations showed a good correlation with tidal cycle. While nutrient concentrations in rainy season showed not much variance in time. There were 6 and 4 times higher dissolved inorganic nitrogen and phosphorus concentrations in the rainy season than those in the dry season, respectively. Silicate concentration was 43 times higher in the rainy season than that in the dry season. Chlorophyll a concentration was higher in the dry season than that in the rainy season showing high nutrient concentrations. The results of this study, spatio-temporal variations of marine environmental factors are determined by both tidal cycle and river discharge. It seems that chlorophyll a concentration is related to the river discharge than dissolved inorganic nutrient distribution.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.46-63
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• 2012

The concept of an "intelligent building" received significant attention from academic, industry and standard development organizations when technically termed a building management system (BMS). Wireless sensor networks (WSNs) and their recent development enhanced monitoring and control applications for the building's areas. This paper surveys and analyzes advantages of the main current and emerging approaches that may be fit for BMS. Specifically, we discuss challenges including interoperability, integration, overhead, and bandwidth limitation of WSNs in BMS. Based on analyses, we highlight the advantages of an IP-based and RESTful architecture approach as the most suitable solution for BMS using WSNs (BMS-WSN). The paper also describes our future direction and design for BMS-WSN based on these advantages. The purpose is to enable interaction of users with BMS-WSN in the same way as with any website while ensuring energy efficiency. A test-bed implementation and evaluation of a BMS application is also introduced in this paper to demonstrate the feasibility and benefits of IP-based and RESTful architecture for BMS.

• Journal of IKEEE
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• v.17 no.3
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• pp.301-308
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• 2013

In this paper, we propose the hybrid lighting control system on multiple sensor. The proposed hybrid lighting control system was designed for management and control of street lightings by configured as the data display part of integration-interworking part, the data conversion-processing part of integrated management part, and the communication part of gateway system. The data are implemented to designing the DB to enable to storage in real-time by enable to monitoring by wireless remote control and schedule set. As a result of the efficiency verification of the proposed hybrid lighting control system, the hybrid lighting control system be to the real-time monitoring and remote lighting control was possible, because to peristalsis with smart devices and portable PC etc., and it could be obtained the effect of energy and electricity, communication cost reduction.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.60-66
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• 2004

Increased energy costs have placed demands for improved combustion efficiency, high equipment availability, low maintenance and safe operation. Simultaneously low NOx modification, installed due to stricter environmental legislations, require very careful combustion management. The flame diagnostics system has been developed specially to meet these requirements. We aimed at gaining the relationship between burner flame image and emissions such as NOx and unburned carbon in furnace by utilizing the image processing method. For the first step of development, its possibility test was undertaken with bench furnace. The test proceeded to the second step with pilot furnace, the system was observed to be effective for evaluating the combustion conditions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.89-97
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• 2012

In recent years, efficient energy management technologies are required, as environmental problems have emerged worldwide. In response to this, smart home services focused on efficient energy management technology seems to be emerging. And the integration of technology of user-oriented real-time energy monitoring and control systems is required. In this paper, we present a location-based green home service using smart phones for efficient energy management in a house. We design a green home network system to apply the green home service, and implement an integrated gateway system which connects and controls each appliance in a house. We develop appliance control services and indoor location services on smart phones, and determine whether user's occupancy of each room by measuring the location according to the variation of signal strength. In order to evaluate the performance of the energy savings, we have set up the scenarios of energy usage pattern and have compared the energy variation resulting from the application of the indoor location services with smart meters. A comparison of energy usage demonstrated that the energy saving of a house with the proposed location-based green home service was down up to 30%.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.121-129
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• 2013

This study investigated the status and problems of the post-project environmental management for development projects and suggested improvements of the system to achieve effectiveness for the system of the sea area utilization consultation. The post-project environmental management has had several problems such as the neglect of implementations and checks for the consultation items, the lack of actions and notifications of results, the absence of awareness and expertise of the post-project environmental management. In addition, although it is very important to verify results of actual change and modelling of marine environment before and after the projects, the marine environmental monitoring and assessment have been perfunctorily carried out. Thus, for the improvements of the post-project environmental management to the system of the sea area utilization consultation, it is extremely necessary for related stakeholders to raise awareness of the post management and implement it faithfully, and establish the post management system for conflict resolution and enforce sanctions and accountability against executory items. Furthermore, it should establish systematic monitoring system of marine environmental impact survey.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.440-454
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• 2020

To prevent pollution from ships, the Energy Efficiency Design Index (EEDI) is a mandatory guideline for all new ships. The Ship Energy Efficiency Management Plan (SEEMP) has also been applied by MARPOL to all existing ships. SEEMP provides the Energy Efficiency Operational Indicator (EEOI) for monitoring the operational efficiency of a ship. By monitoring the EEOI, the shipowner or operator can establish strategic plans, such as routing, hull cleaning, decommissioning, new building, etc. The key parameter in calculating EEOI is Fuel Oil Consumption (FOC). It can be measured on board while a ship is operating. This means that only the shipowner or operator can calculate the EEOI of their own ships. If the EEOI can be calculated without the actual FOC, however, then the other stakeholders, such as the shipbuilding company and Class, or others who don't have the measured FOC, can check how efficiently their ships are operating compared to other ships. In this study, we propose a method to estimate the EEOI without requiring the actual FOC. The Automatic Identification System (AIS) data, ship static data, and environment data that can be publicly obtained are used to calculate the EEOI. Since the public data are of large capacity, big data technologies, specifically Hadoop and Spark, are used. We verify the proposed method using actual data, and the result shows that the proposed method can estimate EEOI from public data without actual FOC.

• Smart Structures and Systems
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• v.14 no.4
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• pp.617-641
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• 2014

The energy constraint is still a common issue for the practical application of wireless sensors, since they are usually powered by batteries which limit their lifetime. In this paper, a practical compound energy efficiency strategy is proposed and realized in the implementation of a real time wireless sensor platform. The platform is intended for wireless structural monitoring applications and consists of three parts, wireless sensing unit, base station and data acquisition and configuration software running in a computer within the Matlab environment. The high energy efficiency of the wireless sensor platform is achieved by a proposed adaptive radio transmission power control algorithm, and some straightforward methods, including adopting low power ICs and high efficient power management circuits, low duty cycle radio polling and switching off radio between two adjacent data packets' transmission. The adaptive transmission power control algorithm is based on the statistical average of the path loss estimations using a moving average filter. The algorithm is implemented in the wireless node and relies on the received signal strength feedback piggybacked in the ACK packet from the base station node to estimate the path loss. Therefore, it does not need any control packet overheads. Several experiments are carried out to investigate the link quality of radio channels, validate and evaluate the proposed adaptive transmission power control algorithm, including static and dynamic experiments.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.152-159
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• 2024

Cracks in structural materials present a critical challenge to infrastructure safety and long-term durability. Timely and precise crack detection is essential for proactive maintenance and the prevention of catastrophic structural failures. This study introduces an innovative approach to tackle this issue using U-Net deep learning architecture. The primary objective of the intended research is to explore the potential of U-Net in enhancing the precision and efficiency of crack detection across various concrete crack detection under various environmental conditions. Commencing with the assembling by a comprehensive dataset featuring diverse images of concrete cracks, optimizing crack visibility and facilitating feature extraction through advanced image processing techniques. A wide range of concrete crack images were collected and used advanced techniques to enhance their visibility. The U-Net model, well recognized for its proficiency in image segmentation tasks, is implemented to achieve precise segmentation and localization of concrete cracks. In terms of accuracy, our research attests to a substantial advancement in automated of 95% across all tested concrete materials, surpassing traditional manual inspection methods. The accuracy extends to detecting cracks of varying sizes, orientations, and challenging lighting conditions, underlining the systems robustness and reliability. The reliability of the proposed model is measured using performance metrics such as, precision(93%), Recall(96%), and F1-score(94%). For validation, the model was tested on a different set of data and confirmed an accuracy of 94%. The results shows that the system consistently performs well, even with different concrete types and lighting conditions. With real-time monitoring capabilities, the system ensures the prompt detection of cracks as they emerge, holding significant potential for reducing risks associated with structural damage and achieving substantial cost savings.