• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.3
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• pp.271-278
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• 2015

This paper develops an OBD Diagnostic Program (Program) using Visual Studio (C#), which was used to diagnosis malfunction information from OBD-II system vehicles. We accomplished this using the Program, Diagnostic tests, Board (STN1110), FTDI Basic Cable, Mini USB Cable, OBD Data Cable, and both hybrid and regular vehicles. The Program tests real-time data output, DTC output, sensor value output, engine RPM, waveform data, OBD type check, PID inspection, and whole monitoring. We found vehicles used in this research had 19 PIDs, which was within OBD-II regulations. We also gathered data on control and diagnostic code regulated by OBD-II system, such as, sensor output value, engine RPM, DTC output, each PID analytic value, OBD type, fuel mode, and whole monitoring result value. Using the data collected through the Program appropriately can lead to more effective diagnostic practices and contribute to education.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.274-279
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• 2016

Aphanisticus congener is a newly recorded buprestid (Coleoptera) insect pest of turfgrass in Korea. This buprestid pest was initially found from turfgrass conservation site in a greenhouse in Jinju, Gyeongnam province, Korea in July, 2014. The Aphanisticus in the family Buprestidae is a leaf miner. A. congener is the close species of A. aeneus which was firstly reported as sugarcane leaf sucker in India. A. congener was active from early July to late August in the greenhouse. Damage by the insect led to drying out and browning of turfgrass leaf because larva fed on cell sap of leaves and adult fed on leaf surface. A. congener damaged Zoysia japonica, Z. sinica, Conodon dactylon, and Poa pratensis when adults were artificially released into potted turfgrasses in the laboratory. In green house, A. congener damaged Z. japonica, Z. macrostachya, Z. matrella, Z. sinica, Conodon dactylon, and hybrid zoysiagrass. However, no damage symptoms were observed from the same turfgrass accessions in the nearby field of the greenhouse. Thus, the new coleopteran pest may be a warm-adapted pest for turfgrass, damaging turfgrass leaf only in warmer conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.12
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• pp.3117-3132
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• 2012

The tree topology in multicast systems has high transmission efficiency, low latency, but poor resilience to node failures. In our work, some nodes are selected as backbone nodes to construct a tree-like core overlay. Backbone nodes are reliable enough and have strong upload capacity as well, which is helpful to overcome the shortcomings of tree topology. The core overlay is organized into a spanning tree while the whole overlay is of mesh-like topology. This paper focuses on improving the performance of the application-layer multicast overlay by optimizing the core overlay which is periodically adjusted with the proposed optimization algorithm. Our approach is to construct the overlay tree based on the out-degree weighted reliability where the reliability of a node is weighted by its upload bandwidth (out-degree). There is no illegal solution during the evolution which ensures the evolution efficiency. Simulation results show that the proposed approach greatly enhances the reliability of the tree-like core overlay systems and achieves shorter delay simultaneously. Its reliability performance is better than the reliability-first algorithm and its delay is very close to that of the degree-first algorithm. The complexity of the proposed algorithm is acceptable for application. Therefore the proposed approach is efficient for the topology optimization of a real multicast overlay.

• Earthquakes and Structures
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• v.17 no.4
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• pp.425-434
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• 2019

The most effective passive vibration control and seismic resistance options in a reinforced concrete (RC) high-rise building (HRB) are the base isolation and the tuned mass damper (TMD) system. Many options, which may be suitable or not for different soil types, with different types of bearing systems, like rubber isolator, friction pendulum isolator and tension/compression isolator, are investigated to resist the base straining actions under five different earthquakes. TMD resists the seismic response, as a control system, by reducing top displacement or the total movement of the structure. Base isolation and TMDs work under seismic load in a different way, so the combination between base isolation and TMDs will reduce the harmful effect of the earthquakes in an effective and systematic way. In this paper, a comprehensive study of the combination of TMDs with three different base-isolator types for three different soil types and under five different earthquakes is conducted. The seismic response results under five different earthquakes of the studied nine RC HRB models (depicted by the top displacement, base shear force and base bending moment) are compared to show the most suitable hybrid passive vibration control system for three different soil types.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4226-4230
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• 2022

The Korea Atomic Energy Research Institute (KAERI) has designed a Hybrid-Low Power Research Reactor (H-LPRR) which can be used for critical assembly and conventional research reactor as well. It is an open tank-in-pool type research reactor (Thermal Power: 50 kW_th) of which the most important applications are Neutron Activation Analysis (NAA), Radioisotope (RI) production, education and training. There are eight irradiation holes on the edge of the reactor core: IR (6 holes for RI production) and NA (2 holes for NAA) holes. In order to quantify the elemental concentration in target samples through the Instrumental Neutron Activation Analysis (INAA), it is necessary to measure neutron spectrum parameters such as thermal neutron flux, the deviation from the ideal 1/E epithermal neutron flux distribution (α), and the thermal-to-epithermal neutron flux ratio (f) for the irradiation holes. In this study, the MCNP6.1 code and FORTRAN 90 language are applied to determine the parameters for the two irradiation holes (NA-SW and NA-NW) in H-LPRR, and in particular its α and f parameters are compared to values of other research reactors. The results confirmed that the neutron irradiation holes in H-LPRR are designed to be sufficiently applied to neutron activation analysis, and its performance is comparable to that of foreign research reactors including the TRIGA MARK II.

• Smart Structures and Systems
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• v.32 no.3
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• pp.179-193
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• 2023

This study explores an alternative to the existing centralized process for data anomaly detection in modern Internet of Things (IoT)-based structural health monitoring (SHM) systems. An edge intelligence framework is proposed for the early detection and classification of various data anomalies facilitating quality enhancement of acquired data before transmitting to a central system. State-of-the-art deep neural network pruning techniques are investigated and compared aiming to significantly reduce the network size so that it can run efficiently on resource-constrained edge devices such as wireless smart sensors. Further, depthwise separable convolution (DSC) is invoked, the integration of which with advanced structural pruning methods exhibited superior compression capability. Last but not least, quantization-aware training (QAT) is adopted for faster processing and lower memory and power consumption. The proposed edge intelligence framework will eventually lead to reduced network overload and latency. This will enable intelligent self-adaptation strategies to be employed to timely deal with a faulty sensor, minimizing the wasteful use of power, memory, and other resources in wireless smart sensors, increasing efficiency, and reducing maintenance costs for modern smart SHM systems. This study presents a theoretical foundation for the proposed framework, the validation of which through actual field trials is a scope for future work.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.66-71
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• 2023

This paper describes a hybrid cleaning method of silicon wafer combining nano-bubble and ultrasound to remove sub-micron particles and contaminants with minimal damage to the wafer surface. In the megasonic cleaning process of semiconductor manufacturing, the cavitation induced by ultrasound can oscillate and collapse violently often with re-entrant jet formation leading to surface damage. The smaller size of cavitation bubbles leads to more stable oscillations with more thermal and viscous damping, thus to less erosive surface cleaning. In this study, ultrasonic energy was applied to the wafer surface in the DI water to excite nano-bubbles at resonance to remove contaminant particles from the surface. A patented nano-bubble generator was developed for the generation of nano-bubbles with concentration of 1×10⁹ bubbles/ml and nominal nano-bubble diameter of 150 nm. Ultrasonic nano-bubble technology improved a contaminant removal efficiency more than 97% for artificial nano-sized particles of alumina and Latex with significant reduction in cleaning time without damage to the wafer surface.

• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.731-744
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• 2014

Extracting students' own culture and resources as main sources in science class, we begin a research to explore teaching and learning settings that are more responsive to adolescents. This study has been designed to explore the funds of knowledge that students bring into middle school science class. It also focused on the features of teaching and learning settings that stimulated the autonomous inflow of students' funds of knowledge as resources of science learning. Data from participant observations and in-depth interviews with 7th grade students were qualitatively analyzed based on grounded theory. We found that students' funds of knowledge were formed from their family life, neighbor communities, peer group, and pop culture. The funds of knowledge based on peer culture emerged as the most salient factor of students' enhanced participation and utterance. Common features of classes that stimulated the inflow of funds of knowledge were analyzed to be: (1) hybrid spaces for learning designed in advance: (2) sharing and enlargement of the funds of knowledge that has been brought into the class: and (3) common orientation of the community of practice for knowledge co-construction and shared outcomes. From these findings, this paper discussed the educational implications for promoting students' potential resources to actual sources of science class. It also discussed students' development of participation specifically among the generally marginalized students. Science classes based on the funds of knowledge of students offer an increased possibility of knowledge co-construction through the hybridized interactions of student's everyday lives and science knowledge and lead to more meaningful learning experiences.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.377-381
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• 2014

In this study, we report for the first time a hybridization between Caretta caretta and Chelonia mydas in South Korea. On 7th May 2012, a sea turtle (Jeju sea turtle 01, JST01) was found in the east coast of Jeju Island, South Korea. The morphological characteristics of JST01 were compared with those of C. caretta and C. mydas that were frequently observed in Korean Seas. Interestingly, JST01 showed similar morphological characters such as body color, appearance of carapace, shape of upper beak, serration on marginal scute, and two claws with those of C. caretta. On the other hand, JST01 showed also similar patterns in several characteristics including the numbers of marginal, inframarginal and costal scute, smooth carapace without keel, no contact between costal scute and nuchal scute with those of C. mydas. From these results, we suggest that JST01 is one of hybrid animals bred between C. caretta and C. mydas, because JST01 has species-specific characters from both species. We anticipate that our study would be useful and have significant impact onto study inter-specific hybridization in the groups of sea turtle.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.285-298
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• 2022

This study is to investigate the effects and characteristics of science and engineering integrated lessons on elementary students' creative engineering problem solving propensity (CEPSP). The science and engineering integrated lessons used in this study was a 10 lesson-hours STEM program, co-developed by University of Minnesota and Purdue University. The program was implemented in the 6th grade science class of H Elementary School located in P Metropolitan city. The main data of this study are the pre-post CEPSP result and interview with 5 students collected before and after the research. The CEPSP result was analyzed by a paired-sample t-test and hierarchical cluster analysis. As a result of the t-test, it was found that overall, the program has a positive effect on the students' CEPSP score. As a result of cluster analysis, it was confirmed that studnets' CEPSP could be classified into two groups (lower and higher score cluster). Five students whose, CEPSP score has significantly improved after the lessons were interviewed to find out what the characteristics of the program that contribute the significant change are. As a result of conducting centroid analysis of the interview transcription and the hybrid analysis method, it was found that the meaningful experiences that the five students commonly shared were 'problem solving through collaboration' and 'through repeated experiments (redesign)', problem solving' and 'utilization of scientific knowledge'. As minor reactions, 'choice of the best experimental method' and 'difference between science and engineering' appeared.