• Journal of the Society of Naval Architects of Korea
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• v.56 no.2
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• pp.143-151
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• 2019

This study describes a method for analyzing log data generated in a process using process mining techniques. A system for collecting and analyzing a large amount of log data generated in the process of manufacturing an offshore plant piping material was constructed. The analyzed data was visualized through various methods. Through the analysis of the process model, it was evaluated whether the process performance was correctly input. Through the pattern analysis of the log data, it is possible to check beforehand whether the problem process occurred. In addition, we analyzed the process performance data of partner companies and identified the load of their processes. These data can be used as reference data for pipe production allocation. Real-time decision-making is required to cope with the various variances that arise in offshore plant production. To do this, we have built a system that can analyze the log data of real - time system and make decisions.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.893-903
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• 2022

Recently, computer vision (CV)-based safety monitoring (i.e., object detection) system has been widely researched in the construction industry. Sufficient and high-quality data collection is required to detect objects accurately. Such data collection is significant for detecting small objects or images from different camera angles. Although several previous studies proposed novel data augmentation and synthetic data generation approaches, it is still not thoroughly addressed (i.e., limited accuracy) in the dynamic construction work environment. In this study, we proposed a game engine-driven synthetic data generation model to enhance the accuracy of the CV-based object detection model, mainly targeting small objects. In the virtual 3D environment, we generated synthetic data to complement training images by altering the virtual camera angles. The main contribution of this paper is to confirm whether synthetic data generated in the game engine can improve the accuracy of the CV-based object detection model.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.41-45
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• 2006

The fabrication process of fiber placement system of carbon fiber reinforced plastic (CFRP) requires real time process control and reliable inspection to ensure quality by preventing defects such as delamination and void. Therefore, novel non-contact inspection technique is required during the non-destructive evaluation in a fiber placement system. For the inspection of delamination in CFRP, various methods to receive laser-generated ultrasound were applied by using piezoelectric transducer, air-coupled transducer, wavelet transform and scanning laser ultrasonic technique. Laser-generated ultrasound was received with a conventional piezoelectric sensor in contacting manner. Then signal characteristics due to defects were analyzed to find a factor for detecting defects. Air-coupled transducer was used for reception of laser-generated guided wave using linear slit array in order to generate high frequency guided wave. And line scan technique was used to confirm the capability of on-line application. The high frequency component of laser-generated guided wave received with piezoelectric sensor disappeared after propagating through delamination region. Nevertheless, it was failed to receive high frequency guided wave in using air-coupled transducer. The first peak of the frequency spectrum under 100kHz in the delamination region is higher than in the sound region. By using this feature, the line scanned frequency data were acquired in fully non-contact generation and reception of ultrasound. This method was proved as useful technique for detecting delamination in CFRP.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.27-33
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• 2017

To efficiently provide cloud computing services to users over the Internet, IT resources must be configured in the data center based on virtualization and distributed computing technology. This paper focuses specifically on the problem that new training data can be added at any time in a wide range of fields, and new attributes can be added to training data at any time. In such a case, rule generated by the training data with the former attribute set can not be used. Moreover, the rule can not be combined with the new data set(with the newly added attributes). This paper proposes further development of the new inference engine that can handle the above case naturally. Rule generated from former data set can be combined with the new data set to form the refined rule.

• Korean Journal of Computational Design and Engineering
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• v.4 no.4
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• pp.381-390
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• 1999

In this study, a pseudo ship structure data model for the :.hip cargo hold structure based on STEP is proposed. The proposed data model is based on Application Reference Model of AP218 Ship Structure which is the model that specifies conceptual structures and constraints used to describe the information requirements of an application. And the proposeddata model refers the Ship Common Model framework for the model architecture which is the basis for ongoing ship AP development within the ISO ship-building group and the ship product definition information model of CSDP research project for analyzing the relationship between ship structure model entities. The proposed data model includes Space, Compartment. Ship Structural System, Structural Part and Structural Feature of cargo hold. To generate this data model schema in EXPRESS format, ‘GX-Converter’was used which enables user to edit a model in EXPRESS format and convert schema file in EXPRESS format. Using this model schema, STEP physical file containing design data for ship cargo hold data structure was generated through SDAI programming. The another STEP physical file was also generated containing geometry data of ship cargo hold which was extracted and calculated by SDAI and external surface/surface intersection program. The geometry information of ship cargo hold can be then transferred to commercial CAD system, for example, Pro/Engineer. Examples of the modification of the design information are also Presented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4643-4660
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• 2014

Integrity authentication of biometric data in Wireless Body Area Network (WBAN) is a critical issue because the sensitive data transmitted over broadcast wireless channels could be attacked easily. However, traditional cryptograph-based integrity authentication schemes are not suitable for WBAN as they consume much computational resource on the sensor nodes with limited memory, computational capability and power. To address this problem, a novel lightweight integrity authentication scheme based on reversible watermark is proposed for WBAN and implemented on a TinyOS-based WBAN test bed in this paper. In the proposed scheme, the data is divided into groups with a fixed size to improve grouping efficiency; the histogram shifting technique is adopted to avoid possible underflow or overflow; local maps are generated to restore the shifted data; and the watermarks are generated and embedded in a chaining way for integrity authentication. Our analytic and experimental results demonstrate that the integrity of biometric data can be reliably authenticated with low cost, and the data can be entirely recovered for healthcare applications by using our proposed scheme.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.981-983
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• 2003

The Remote Sensing Group of the Mines and Geosciences Bureau (MGB) has acquired SAR data of the Central Cebu Island for its research study area. The MGB is one of the proponent of DOST-NASA PACRIM II Project, which is composed of eleven (11) agencies and institutions in the Philippines, that focuses on the scientific application of radar data with the theme on hazard and natural resources management. The PACRIM II Project, being done on three-year term, is slated for completion in the year 2004. The main thrust of the project study of the MGB is the baseline environmental monitoring studies, on which the data are to be fused with some other available data from LandSAT and photogrammetry. The generated data is part of the information for the update of thematic mapping being done. The 12 ${\times}$ 60 km swath AirSAR data covers the Central Cebu Island. The highlights of conducting this research project are: Extent of Watershed Basin boundaries - identification of the tributaries that drain water supply to the metropolitan area; Monitoring of the mountain highways - identification of landslide risk prone sites as part of natural hazard monitoring on a national highway that cuts along the mountainous areas; and Coastline change assessment - monitoring the coastline activities relative to the rapid urbanization and exposure as part of coastal management. The Phase 1 of this report discusses the fusion with the ArcView generated data as baseline studies on the monitoring activities.

• International Journal of Computer Science & Network Security
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• v.23 no.3
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• pp.10-16
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• 2023

The ever-increasing amount of data generated by various industries and systems has led to the development of data mining techniques as a means to extract valuable insights and knowledge from such data. The electrical energy industry is no exception, with the large amounts of data generated by SCADA systems. This study focuses on the analysis of historical data recorded in the SCADA database of the Libyan Electricity Company. The database, spanned from January 1st, 2013, to December 31st, 2022, contains records of daily date and hour, energy production, temperature, humidity, wind speed, and energy consumption levels. The data was pre-processed and analyzed using the WEKA tool and the Apriori algorithm, a supervised machine learning technique. The aim of the study was to extract association rules that would assist decision-makers in making informed decisions with greater efficiency and reduced costs. The results obtained from the study were evaluated in terms of accuracy and production time, and the conclusion of the study shows that the results are promising and encouraging for future use in the Libyan Electricity Company. The study highlights the importance of data mining and the benefits of utilizing machine learning technology in decision-making processes.

• Spatial Information Research
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• v.19 no.5
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• pp.13-25
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• 2011

Until now, most of the Web GIS system has been developed with one-sided service type that provides pre-built spatial information to users. Recently, however, interactive web system is getting attention because users can create directly spatial information contents that meet their needs. In line with this trend, this study had a aim to develop a UGC(User Generated Contents) support system for marine science researchers who can generate spatial data by themselves on the web. The main advantage of this system is that it provides marine survey data and marine spatial information that needed to work for marine science research. Furthermore, it provides the functions of extracting of coastline as point data for their marine study area, and making of the spatial planning map for marine field survey work and marine science thematic maps for exploratory analysis after research survey. Such kinds of interactive UGC support system gives researchers a chance for utilizing marine spatial information more easily. Therefore, it is expected that the improving of the efficiency of research works, as well as increasing of the utilization of marine spatial data.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.73-79
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• 2012

Because the contact time between satellite and ground station is very limited in LEO (Low Earth Orbit) satellite, all telemetry data generated on spacecraft bus are stored in a mass memory and downlinked to the ground together with real time data during the contact time. The mass memory is initialized in the first system initialization phase and the page status of each memory block is generated step by step. After the completion of the system initialization, the telemetry data are continuously stored and the stored data are played back to the ground by command. And the memory scrubbing is periodically performed for correction of single bit error which can be generated on harsh space environment. This paper introduces the mass memory operation method for telemetry processing of LEO satellite. It includes a general mass memory data structure, the methods of mass memory initialization, scrubbing, data storage and downlink, and mass memory management of primary and redundant mass memory.