• Proceedings of the KIEE Conference
• /
• 2006.07d
• /
• pp.2077-2078
• /
• 2006

This paper describes the development or a closed-loop Strapdown Attitude Reference System (SARS) algorithm integrated filtering estimator for determining attitude reference for railway and aviation system using fuzzy inference. The SARS consists of 3 single-axis rate gyms in conjunction with 2 single-axis accelerometers. For optimal values of fuzzy systems, we utilize on-line scheduling method for initial values and then use genetic algorithms for fine tuning. Implementation using experimental test data of unmanned aerial vehicle has been performed in order to verify the estimation. The proposed fuzzy inference based SARS demonstrate that more accurate performance can be achieved in comparison with conventional one. The estimation results were compared with the on-board vertical gyro as the reference standard.

• International Journal of Precision Engineering and Manufacturing
• /
• v.6 no.2
• /
• pp.34-39
• /
• 2005

The precision stage is an essential device for optic fiber assembly systems, micro machines and semiconductor equipments. A new piezoelectric inchworm type actuator is proposed to implement an actuator-integrated long-stroke linear stage. An in-and-quadrature phase (I/Q) heterodyne interferometer is developed as a feedback sensor of a servo system, and a synchronized counting method is proposed. The proposed measurement system can measure the accurate position of fast moving object with robustness to external sensing noise from actuator vibration. The developed servo stage will be applied to optic fiber device assembly system.

• KEPCO Journal on Electric Power and Energy
• /
• v.1 no.1
• /
• pp.47-54
• /
• 2015

The most important function in distribution automation system (DAS) is the service restoration. KEPCO's current service restoration provides a very effective restoration service. However, it has been developed without the consideration of unexpected abnormal conditions that may occur while processing the sequence of switching operations. The objective of this paper is to provide practical service restoration schemes under consideration of abnormal conditions. The proposed service restoration schemes have been integrated to a branch office (B/O) in KEPCO. The proposed method strongly supports the conventional service restoration and adds to its value.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2020.07a
• /
• pp.225-226
• /
• 2020

현대 사회에서는 재난의 유형과 피해가 다양해지고 이에 따른 위험성이 증가하여 재난에 대응하기 위한 운영 및 관리의 필요성이 증가하고 있다. 특히 건축물의 대형화, 복잡화로 인하여 대규모 상업시설 및 다중이용시설은 실내 구조가 복잡하기 때문에 재난 발생 시 안전한 대피 경로를 파악하여 이동하는 것이 어려운 문제가 있다. 이에 본 연구에서는 재난 발생 시에 대규모 시설 내에서 이용자가 안전한 대피경로를 확인하고 이동할 수 있도록 지원하기 위한 통합관제체계 구축 방안에 대해서 연구하였다. 본 연구에서 제시하는 통합관제체계와 스마트폰 어플리케이션을 연계하여 재난 발생 시, 시설 이용자에게 안전한 대피경로를 안내함으로써 실내 공간에서의 대패를 지원할 수 있다.

• Journal of Species Research
• /
• v.13 no.1
• /
• pp.41-49
• /
• 2024

Chironomus is a large genus of Diptera comprising about 400 species and occurs worldwide except for Antarctica. The strong morphological cross-taxon similarity of chironomid larvae renders identification at the species level difficult. Here, we analyzed the morphology of larvae of Chironomus flaviplumus, an easily cultured species employed as a bioindicator in polluted environments, to determine identifying morphological characteristics at the first through fourth instar. Observed differences appearing at each instar include the presence or absence of setae on the body and tubules on the 10^th and 11^th body segment, the number of seta interna in the mandible, and the presence or absence of ring organs in the antennae. Some specific morphological characteristics did not change after hatching. Our findings provide a reliable method for identifying C. flaviplumus larvae.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.4
• /
• pp.33-41
• /
• 2014

This paper presents an effective memory access method for a high-speed data transfer on mobile systems using a direct memory access controller that considers the characteristics of a multi-port memory controller. The direct memory access controller has an integrated channel management function to control multiple direct memory access channels. The channels are physically separated and operate independently from each other. Experimental results show that the proposed direct memory access method improves the transfer performance by up to 72% and 69% on read and write transfer cycles, respectively. The total number of transfer cycles of the proposed method is 63% less than in a commercial method under 4-channel access.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.6
• /
• pp.77-81
• /
• 2008

In the deeply coupled GPS/INS integrated systems, if the integration filter update period is longer than the period of GPS navigation data, the loss of correlation values occurs due to the bit transition. This problem can be resolved when data wipe off(DWO) is used. However, general DWO methods requires heavy computation or cannot be applied continuously. This paper proposes an effective DWO method using carrier phase discriminator In order to show validity of the proposed method, simulations were carried out. The simulation results show that the data bit is accurately estimated and conform that the loss of correlation values and the error of code phase is small.

• Nuclear Engineering and Technology
• /
• v.49 no.1
• /
• pp.148-164
• /
• 2017

The focus on the issues surrounding spent nuclear fuel and lifetime extension of old nuclear power plants continues to grow nowadays. A transparent decision-making process to identify the best suitable nuclear fuel cycle (NFC) is considered to be the key task in the current situation. Through this study, an attempt is made to develop an equilibrium model for the NFC to calculate the material flows based on 1 TWh of electricity production, and to perform integrated multicriteria decision-making method analyses via the analytic hierarchy process technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory methods. This comparative study is aimed at screening and ranking the three selected NFC options against five aspects: sustainability, environmental friendliness, economics, proliferation resistance, and technical feasibility. The selected fuel cycle options include pressurized water reactor (PWR) once-through cycle, PWR mixed oxide cycle, or pyroprocessing sodium-cooled fast reactor cycle. A sensitivity analysis was performed to prove the robustness of the results and explore the influence of criteria on the obtained ranking. As a result of the comparative analysis, the pyroprocessing sodium-cooled fast reactor cycle is determined to be the most competitive option among the NFC scenarios.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.5
• /
• pp.40-48
• /
• 2013

Eco deck plate system is a construction method that deconstruction of galvanized steel sheets is possible by integrating steel-wire-integrated girders and the galvanized steel sheets with bolts. Therefore, compared with previous steel-wire-integrated deck plates which were joined by welding, the system is acknowledged as the construction method possible management and repair. This study conducted an experimental research by manufacturing total 24 full size specimens in a same condition for 12-shape specimens by two parts to evaluate structural behaviors of the eco deck plates. In the results after the test, permissible deflection for the construction load action was shown to be values under design values and satisfactory. The processing of lattice steel wires was presented to be structurally advantageous in being manufactured by cutting downward. Also, in case of a specimen that D13 as a steel wire was used, destruction occurred at the welding part of the bottom steel wire and the lattice steel wire, so improvement measures for the welding in factory manufacture are necessary.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.4
• /
• pp.69-77
• /
• 2019

In this study, we evaluated the mechanical properties and nitrogen oxides removal characteristics according to the type and incorporation rate of the photocatalyst and investigated the method of separated placement for the production of economical and efficient photocatalyst concrete. As a result, when the photocatalyst incorporation rate was 5%, the highest compressive strength and elastic modulus were measured. As a result of evaluating the nitrogen oxides removal performance by the photocatalytic reaction, as the photocatalyst incorporation rate increased, the nitrogen oxide removal rate increased. At this time, the nitrogen oxides removal performance of photocatalyst P-25 was better than the NP-A. In consideration of economic efficiency, we have provided a method of separated placement for casting a constant thickness of concrete surface with photocatalyst concrete and evaluated the integrated performance at this time. As a result, it appears to be equal to or higher than mechanical performance and durability performance as compared with Plain, and it is judged that the integrated behavior is satisfied.