• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.375-378
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• 2017

Shipping and logistics safety, security system is strengthening worldwide, the development of shipping and logistics safety security core technology for national security logistics system construction has been carried out. In addition, it is necessary to localize the Array Detection System, which is a core component of the container search machine, to cope with the 100% pre-inspection of the container scheduled for 2018 in the United States. In this paper, we propose a study on a self-developed Digital Signal Processing Board among the array detection systems that replace foreign products.

• Journal of Digital Contents Society
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• v.19 no.6
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• pp.1219-1224
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• 2018

Nowaday, smart mobile devices on Internet of Things are required to process and deliver greate amount of data in real-time. Therefore, heterogeneous mult-core architecture such the big.LITTLE core architecture, which shows high energy conservation while guaranteeing high performance, are widely employed on up to date smart mobile devices. The LITTLE cores should be highly utilized to gain higher energy conservation because LITTLE cores have much higher energy efficiency than big cores. In this paper, we propose a core selection algorithm, which tries to firstly assign a real-time task on a LITTLE core rather a big core while the task can be finished within its own deadline. We also perform simulation as performance evaluation to show that our proposed algorithm shows higher energy conservation while guaranteeing the required performance.

• Journal of Digital Convergence
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• v.11 no.6
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• pp.257-267
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• 2013

Disaster Experience, Perception and Core Competencies on Disaster Nursing of Nursing Students. This paper was aimed to investigate disaster experience, perception and core competencies on disaster nursing of nursing students and to provide basic data needed for development of disaster nursing program. 172 nursing students enrolled in a department of nursing completed questionnaires. The data were collected from December 1, 2012 to December 23, 2012. The result were as follows; The average level of perception about disaster nursing was 18.16 out of 25 points, suggesting that they generally perceived disaster nursing as an important matter. Core competencies of the subjects on disaster nursing was 41.56 out of 75 points, which was moderate for the core competencies on disaster nursing. There was statistically significant positive correlation between the perception about disaster nursing and core competencies on disaster nursing. It is necessary to develop disaster nursing program to reflect the needs of the field in Korea. Further research is needed to adequately address this issue.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.97-105
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• 2017

The subjects were 500 college students in 7 provincial areas for the study on the structural relation among professors' core competency, college students' cognitive learning competency and life competencies. The statistical methods of this study were as follows: frequency analysis, descriptive statistic analysis, exploratory factor analysis, reliability analysis, correlation analysis, confirmatory factor analysis, and structure equation model analysis. The results of the study are as follows. First, the lifelong learning educators' college students recognized core competency significantly affects on the college students' life competencies. Second, the lifelong learning educators' core competency significantly affects on the college students' cognitive learning competency. Third, the college students' cognitive learning competency significantly affects on life competencies. Fourth, the college students' cognitive learning competency has a significant mediating effect between the lifelong learning educators' core competency and the college students' life competencies. In other words, the lifelong learning educators' core competency based on the college students' cognitive learning competency has great effect on life competencies.

• Transactions of Materials Processing
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• v.32 no.1
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• pp.12-19
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• 2023

The armature core is a part responsible for the skeleton of the steering wheel. Currently, in the case of commercial trucks, the main parts of the parts are manufactured separately and then the product is produced through welding. In the case of this production method, quality and cost problems of the welded parts occur, and an integrated armature core made of magnesium alloy is used in passenger vehicles. However, in the case of commercial trucks, there is no application case and research is insufficient. Therefore, this study aims to develop an all-in-one armature core that simultaneously applies a magnesium alloy material and a die casting method to reduce the weight and improve the quality of the existing steel armature core. The product was modeled based on the shape of a commercial product, and finite element analysis (FEA) was performed through Ls-dyna, a general-purpose analysis program. Through digital image correlation (DIC) and uniaxial tensile test, the accurate physical properties of the material were obtained and applied to the analysis. A total of four types of compression were applied by changing the angle and ground contact area of the product according to the actual reliability test conditions. analysis was carried out. As a result of FEA, it was confirmed that damage occurred in the spoke area, and spoke thickness (t_spoke), base thickness (t_base), and rim and spoke connection (R) were designated as design variables, and the total weight and maximum equivalent stress occurring in the armature core We specify an objective function that simultaneously minimizes . A prediction function was derived using the sequential response surface method to identify design variables that minimized the objective function, and it was confirmed that it was improved by 22%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.9
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• pp.827-832
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• 2011

Communication is very important in warfare. Dispatch riders were used in ancient warfare, but communication system is used in modern warfare, as the advancement of communication equipments. In order to weaken enemy military strength, communication jamming signal disrupts enemy communication systems. Tone jamming is one of the common communication jamming techniques. Tone jamming is that several tones are placed in the spectrum for neutralizing the enemy's radio communication receivers. In this paper, we develop multitone jamming signal controlled tone number up to 10 tones and tone interval between tones using DDS(Direct Digital Synthesizer) core and FPGA(Field Programmable Gate Arry) of Xilinx Inc. and show the jamming signal output.

• ETRI Journal
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• v.37 no.6
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• pp.1176-1187
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• 2015

This work proposes a highly efficient sensorless motor driver chip for various permanent-magnet synchronous motors (PMSMs) in a wide power range. The motor driver chip is composed of two important parts. The digital part is a sensorless controller consisting mainly of an angle estimation block and a speed control block. The analog part consists of a gate driver, which is able to sense the phase current of a motor. The sensorless algorithms adapted in this paper include a sliding mode observer (SMO) method that has high robust characteristics regarding parameter variations of PMSMs. Fabricated SMO chips detect back electromotive force signals. Furthermore, motor current-sensing blocks are included with a 10-bit successive approximation analog-to-digital converter and various gain current amplifiers for proper sensorless operations. Through a fabricated SMO chip, we were able to demonstrate rated powers of 32 W, 200 W, and 1,500 W.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.3
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• pp.83-95
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• 2022

A technology can be newly formed through technological convergence achieved by the intersection of two or more technological fields. As the complexity of technology development increases, related interest is increasing. Researches have been carried out on the concept, related indicators and analysis of technology convergence including method of social networks. This paper intends to suggest an analysis method of technology convergence using social networks based on the company's possessing technologies. According to the similarity of technologies among companies, a social network was constructed and the technology convergence was analyzed using k-core, a social network subgroup method. Using the result of k-core, base and element technologies for convergence was identified with their relations. Using the suggested method, technology convergence was analyzed on real technology data of defense-industry companies. When the minimum technology similarity is 0, the overall technology convergence relations between technology elements can be identified. In the scope of data in this paper, technologies of defense S/W, aircraft structure and structural materials are identified as important base technology for convergence.

• Journal of Technologic Dentistry
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• v.46 no.1
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• pp.15-19
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• 2024

An ideal post material should have physical properties similar to those of dentin. Post materials with high elastic moduli may cause root fractures. This clinical report describes the treatment of a severely damaged tooth using a recently introduced material. Polyetherketoneketone (PEKK) is a semicrystalline high-performance thermoplastic polymer. PEKK is a promising material for custom post-and-core fabrication because of its elasticity close to that of dentin, good shock absorbance, machinability, and low cost. A laboratory scanner was used to digitize the conventional impression of a severely damaged maxillary right first molar. A custom PEKK post-and-core was designed and milled using computer-aided design and computer-aided manufacturing technology. Using the proposed technique, a custom PEKK post-and-core was fabricated accurately and human error was reduced. Restoration was luted with resin cement. Custom PEKK post-and-core restorations are a viable alternative for treating severely damaged teeth.

• Nuclear Engineering and Technology
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• v.36 no.1
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• pp.53-63
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• 2004

The research was performed to develop a CANDU-6 Core Monitoring System(CCMS) that enables operators to have efficient core management by monitoring core power distribution, burnup distribution, and the other important core variables and managing the past core history for Wolsong nuclear power plant unit 1. The CCMS uses Reactor Fueling Simulation Program(RFSP, developed by AECL) for continuous core calculation by integrating the algorithm and assumptions validated and uses the information taken from Digital Control Computer(DCC) for the purpose of producing basic input data. The CCMS has two modules; CCMS server program and CCMS client program. The CCMS server program performs automatic and continuous core calculation and manages overall output controlled by DataBase Management System. The CCMS client program enables users to monitor current and past core status in the predefined GUI(Graphic-User Interface) environment. For the purpose of verifying the effectiveness of CCMS, we compared field-test data with the data used for Wolsong unit 1 operation. In the verification the mean percent differences of both cases were the same($0.008\%$), which showed that the CCMS could monitor core behaviors well.