• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.55-62
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• 2011

Recently, construction work has diversified and become larger. So, a systematic measurement and management measures are required. In this study, USN technology which is one of the most important network technologies was selected. Based on elements derived from comparison of each element of standard was calculated according to the importance of the elements. The importance of the decision to support the proposed model is explained by integrating the importance of each criteria and decision-support model by considering the situation and creating a matrix of considerations for the construction of earthwork. The results of this study show that USN technology in the context of judging criteria can be selected for the earthwork.

• Spatial Information Research
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• v.20 no.6
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• pp.119-127
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• 2012

u-City is next generation city which can innovate functions of city. It can realize increase of convenience, improvement of life quality and safety guarantee by convergence of information technologies and ubiquitous service with urban space. Market of u-City is in range of rapid growth and u-City can make enormous synergy effects by accompanying construction technologies with spatial information, sensor technologies, communications network and related equipments. In this study, we analyzed the domestic/abroad status, researches and element technologies involved in u-City. And, we suggested overseas expansion strategy of u-City such as selection and analysis of target nations, packaging method of u-City service models and application of BIM/GIS connection technologies in terms of u-City construction and operation.

• Journal of Sensor Science and Technology
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• v.12 no.6
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• pp.289-297
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• 2003

In this paper, we propose accurate classification method of an EEG signals during a mental tasks. In the experimental task, subjects achieved through the process of responding to visual stimulus, understanding the given problem, controlling hand motions, and select a key. To recognize the subjects' selection time, we analyzed with 4 types feature from the filtered brain waves at frequency bands of $\alpha$, $\beta$, $\theta$, $\gamma$ waves. From the analysed features, we construct specific rules for each subject meta rules including common factors in all subjects. In this system, the architecture of the neural network is a three layered feedforward networks with one hidden layer which implements the error back propagation learning algorithm. Applying the algorithms to 4 subjects show 87% classification success rates. In this paper, the proposed detection method can be a basic technology for brain-computer-interface by combining with discrimination methods.

• Journal of Astronomy and Space Sciences
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• v.19 no.3
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• pp.215-224
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• 2002

This paper describes EGSE design for the small satellite such like KOMPSAT-2 satellite. Recent design trend of small satellite and EGSE is to take short development time and less cost. For this purpose, the design for KOMPSAT-2 satellite and EGSE are not much modified from KOMPSAT-1 heritage. It means that it is able to be accommodated the verified hardware and software modules used in KOMPSAT-1 satellite program if possible. The objective of EGSE is to provide hardware and software for efficient electrical testing of integrated KOMPSAT-2 satellite in three general categories. (1) Simulators for ground testing (e.g. solar-simulation power, earth scenes, horizons and sun sensor). (2) Ground station type satellite data acquisition and processing test sets. (3) Overall control of satellite using hardline datum. In KOMPSAT (KOrea Multi-Purpose SATellite) program, KOMPSAT-2 EGSE was developed to support satellite integration and test activities. The KOMPSAT-2 EGSE was designed in parallel with satellite design. Consequently, the KOMPSAT-2 EGSE was based on the KOMPSAT-1 heritage since the spacecraft design followed the heritage. The KOMPSAT-2 baseline was elaborated by taking advantage of experience from KOMPSAT-1 program. The EGSE of KOMPSAT-2 design concept is generic modular design with preference in part selection with commercial off-the-shelf which were proven from KOMPSAT-1 programs, flexible/user friendly operational environment (graphical interface preferred), minimized new design and self test capability.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.635-651
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• 2012

To produce a level-3 monthly composite image from daily level-2 Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll-a concentration data set in the East Sea, we applied four average methods such as the simple average method, the geometric mean method, the maximum likelihood average method, and the weighted averaging method. Prior to performing each averaging method, we classified all pixels into normal pixels and abnormal speckles with anomalously high chlorophyll-a concentrations to eliminate speckles from the following procedure for composite methods. As a result, all composite maps did not contain the erratic effect of speckles. The geometric mean method tended to underestimate chlorophyll-a concentration values all the time as compared with other methods. The weighted averaging method was quite similar to the simple average method, however, it had a tendency to be overestimated at high-value range of chlorophyll-a concentration. Maximum likelihood method was almost similar to the simple average method by demonstrating small variance and high correlation (r=0.9962) of the differences between the two. However, it still had the disadvantage that it was very sensitive in the presence of speckles within a bin. The geometric mean was most significantly deviated from the remaining methods regardless of the magnitude of chlorophyll-a concentration values. Its bias error tended to be large when the standard deviation within a bin increased with less uniformity. It was more biased when data uniformity became small. All the methods exhibited large errors as chlorophyll-a concentration values dominantly scatter in terms of time and space. This study emphasizes the importance of the speckle removal process and proper selection of average methods to reduce composite errors for diverse scientific applications of satellite-derived chlorophyll-a concentration data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.981-987
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• 2009

Recently, the study on wireless body area network for providing ubiquitous healthcare services has been actively done, including the standardization of the IEEE and others. Wireless body area network is usually configured in tree format using multi-hop communication mode due to the power limitation and the characteristics of human body. In this case, differently from existing sensor network, the wireless body area network tends to be disconnected due to the frequent movement of human body. The number of connections which can be supported at each node has some limitations due to the constraint imposed on power consumption. In this paper, we have proposed a heuristic algorithm for optimal selection of parent node with guaranteed QoS for a disconnected node, which considers the priority on packet transmission. Simulation has been performed to evaluate the performance of the proposed algorithm.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.153-163
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• 2013

As recent buildings have been more higher and larger, construction vertical lifting planning and operation is a key factor for successful project in tall building. Although many studies have been trying to set up a construction lifting planning system at early stage, there's not existing a control real-time lift operation control system with respect to during construction stage. Therefore, In this study, we use the sensor device to collect the lift operating data for improvement of lift operation efficiency and develope optimum lift operating system which can perform real-time analysis. Finally, we verify the efficiency of proposed system through comparison between realtime operating data and simulated data using proposing system. In this paper, the proposed system show more efficient moving line compared with previous system. This can contribute to development of unmanned lift system.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1936-1938
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• 2000

In this paper, a frequency spectra of AE (acoustic emission) signals detected from the partial discharges of an epoxy resin void and a cast resin transformer in operating were analyzed to offer the proper frequency range of AE signals from the corona discharge for the purpose of AE sensor selection, From these results, a frequency spectra of AE signals emitted from the corona discharges in the void of an epoxy resin sample were about 190[kHz] to 220[kHz] by the FFT(fast fourier transform), A frequency spectra of AE signals emitted from a cast. resin transformer with non-load were appeared to be downward of about 140[kHz] by the FFT, and then a frequency spectra of AE signals emitted from the above of cast resin transformer with load were appeared to increase from about 190[kHz] to 220[kHz] by the FFT.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.119-126
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• 2020

The purpose of this study is to identify trends in the type and method of Inertial Measurement Unit (IMU) by investigating studies on the type and method of convergence study of the IMU by systematic review. The study was conducted using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. 23 studies that meet the selection criteria were selected from 630 studies identified by three databases. As a result of this study, showed that various research using IMU was being conducted around the world, and the type of IMU was strap, full body suit, belt, wrist watch, shoes and glove. Among them, the number of strap-type IMUs was the largest at 11. The IMU's strengths were simplicity, real-time data collection and ease of application, which were used as measurement methods such as task, walking, and range of joint. The result of this study is expected to be used as basic data for experts in the medical and rehabilitation fields that conduct IMU research.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.468-479
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• 2016

In order to supply power to online monitoring systems that are attached to high voltage catenary or overhead wires, a wireless power transfer system is required that is able to transmit power over the insulation gap. Such wireless power transfer systems have transmitter and receiver coils that have diameters of over 10cm. This paper focused on an investigation of the sources of loss in the coils when the coils are fabricated using printed circuit board technology. Using finite element simulation results, it has been shown that the dielectric loss in the substrate was the dominant source of the total loss. It has been demonstrated that the selection of a proper dielectric material was the most critical factor in reducing the loss. For further reduction of the loss, the distributed tuning capacitor method and the slotting of the inter-turn spaces have been proposed. For the evaluation of the proposed methods, four coils have been fabricated and their equivalent series resistances and quality factors were measured. Measured quality factors were greater than 300, which means that these devices will be helpful in achieving high coil-to-coil efficiency.