• International journal of advanced smart convergence
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• v.10 no.4
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• pp.278-288
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• 2021

Recently, IoT systems are cloud-based, so that continuous and large amounts of data collected from sensor nodes are processed in the data server through the cloud. However, in the centralized configuration of large-scale cloud computing, computational processing must be performed at a physical location where data collection and processing take place, and the need for edge computers to reduce the network load of the cloud system is gradually expanding. In this paper, a cluster system consisting of 6 inexpensive Raspberry Pi boards was constructed to perform fast data processing. And we propose "Kubernetes cluster system(KCS)" for processing large data collection and analysis by model distribution and data pipeline method. To compare the performance of this study, an ensemble model of deep learning was built, and the accuracy, processing performance, and processing time through the proposed KCS system and model distribution were compared and analyzed. As a result, the ensemble model was excellent in accuracy, but the KCS implemented as a data pipeline proved to be superior in processing speed..

• Laboraroty Animal Research
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• v.34 no.4
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• pp.133-139
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• 2018

Nonalcoholic steatohepatitis (NASH) is becoming common chronic liver disease because of the increasing global prevalence of obesity and consequently Nonalcoholic fatty liver disease (NAFLD). However, the mechanism for progression of NAFLD to NASH and then cirrhosis is not completely understood, yet. The triggering of these hepatic diseases is thought from hepatocyte injury caused by over-accumulated lipid toxicity. Injured hepatocytes release damage-associated molecular patterns (DAMPs), which can stimulate the Kupffer cells (KCs), liver-resident macrophages, to release pro-inflammatory cytokines and chemokines, and recruit monocyte-derived macrophages (MDMs). The increased activation of KCs and recruitment of MDMs accelerate the progression of NAFLD to NASH and cirrhosis. Therefore, characterization for activation of hepatic macrophages, both KCs and MDMs, is a baseline to figure out the progression of hepatic diseases. The purpose of this review is to discuss the current understanding of mechanisms of NAFLD and NASH, mainly focusing on characterization and function of hepatic macrophages and suggests the regulators of hepatic macrophages as the therapeutic target in hepatic diseases.

• Communications of Mathematical Education
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• v.26 no.1
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• pp.71-84
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• 2012

The purpose of this study is to analyze some Korean elementary pre-service teachers' Mathematical Knowledge for Teaching(MKT) and compare the results with those obtained by Kwon, Nam, & Kim(2009), so that we can provide some suggestions to improve education of elementary mathematics subject at Korean teachers colleges. For this purpose, we selected the MKT items on number and operations which were adapted for Korean in-service teachers by Kwon et al. The survey consisting of those items was administered to 88 Korean elementary pre-service teachers at teachers college, J University. The results are the following: First, the respondents, elementary pre-service teachers, showed that they already had a sufficient amount of Content Knowledge(CK) on number and operations, but that their level of Knowledge of Content and Students(KCS) was insufficient. This means we need to strengthen our students' KCS in education of elementary mathematics subject at our teachers colleges. Second, there was a strong correlation, in both CK and KCS, of item difficulty felt by the respondents with that by the Kwon et al's in-service teachers. Third, although the respondents valued the MKT items more than the above-mentioned elementary in-service teachers, about 70% of them said the items were never learned at their college. Furthermore, they had different opinions on some of the items from their counterparts'. The suggestions we get here are we need to first consider the results in improving education of elementary mathematics subject at our teachers colleges and second develop MKT items suitable for the situation of Korean schools and curriculums in order to obtain exact estimations of Korean elementary pre-service teachers' MKT.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2192-2193
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• 2011

VCU(Vehicle Control Unit) was developed to decrease the wire weight and make it easy to control the power of ECU in bimodal tram. VCU consists of CC(Central Computer), DU(Display Unit), TU(Terminal Unit) with PCB. CC is a main controller with progamming and DU displays the status with graphic symbols and letters. TU with PCB inputs and output the voltage controlled by CC. They communicate with CAN(Controller Area Network). VCU had been verified with software reliability verification test and environmental hardware test. This paper has shown the test results and application to bimodal tram.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.4
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• pp.225-232
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• 2011

In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 ($C_B$=0.60) hull and KRISO container ship (KCS), a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI). The computational results were validated by comparing with the existing experimental data.

• Communications of Mathematical Education
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• v.30 no.1
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• pp.101-120
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• 2016

The purposes of the study were to analyze pre-service mathematics teachers' MKT and to examine the perceptions of MKT to find implications for the improvement of pre-service mathematics teacher education program in the aspect of teachers' content knowledge. Twenty-six pre-service mathematics teachers participated in the survey to examine the perceptions of MKT and they also finished two MKT tasks which focused on a specific area of middle school geometry. According to the survey results, the participants thought that they have enough knowledge in all categories of MKT except KCT-2 and they appreciated the importance of MKT education in pre-service mathematics teacher education program. However, the participants showed difficulties in MKT task items which required SCK, KCS, KCT, especially, the proportions of those who showed appropriate knowledge on the items required SCK and KCT was less than 50%. These results show disagreement between the perceptions of pre-service mathematics teachers' MKT and practice of MKT.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.5
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• pp.419-428
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• 2014

This paper presents a numerical simulation method for the flow around advancing ships in regular waves by using a rectilinear grid system. Because the grid lines do not consist with body surface in the rectilinear grid system, the body geometries are defined by the interaction points of those grid lines and the body surface. For the satisfaction of body boundary conditions, no-slip and divergence free conditions are imposed on the body surface and body boundary cells, respectively. Meanwhile, free surface is defined with the modified marker density method. The pressure on the free surface is determined to make the pressure gradient terms of the governing equations continuous, and the velocity around the free surface is calculated with the pressure on the free surface. To validate the present numerical method, a vortex induced vibration (VIV) phenomenon and flows around an advancing Wigley III ship model in various regular waves are simulated, and the results are compared with existing and corresponding research data. Also, to check the applicability to practical ship model, flows around KRISO Container Ship (KCS) model advancing in calm water are numerically simulated. On the simulations, the trim and the sinkage are set free to compare the running attitude with some other experimental data. Moreover, flows around the KCS model in regular waves are also simulated.

• Journal of Veterinary Clinics
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• v.32 no.4
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• pp.356-358
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• 2015

When severely large corneal perforation occurs, penetrating keratoplasty is a treatment of choice alternative to enucleation. A twelve-year-old male Shih Tzu was referred with perforated corneal ulcer secondary to keratoconjunctivitis sicca (KCS). Perforated cornea was directly sutured using 10-0 non-absorbable suture material, and rotational conjunctival flap was performed. However, re-perforation of cornea by wound dehiscence was observed at 1 month after operation. The yellowish lens escaped outside the orbit during corneal re-perforation, the diagnosis was re-perforated corneal ulcer, moderate corneal edema, moderate KCS (STT; 6 mm) and endophthalmitis caused by escaped lens outside orbit. Accordingly, penetrating keratoplasty (PK) and evisceration through corneal recipient site and intrascleral silicone ball prosthesis were carried out as the planned treatment, and resulted in good cosmetic improvement compared to enucliation. However, exposure of silicone ball occurred at the 9 months after the surgery due to the irritation of implant, thus enucleation was performed. In perforated large corneal ulcer with severe intraocular damage, evisceration with silicone ball insertion with PK would be alternative treatment choice to improve the cosmetic appearance.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.5
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• pp.296-305
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• 2022

In order to investigate maneuvering characteristics of KCS in waves, captive model test in regular waves was conducted. Purpose of the test is measuring maneuvering hull forces when ship is maneuvering in waves. Model test was carried out using CPMC (Computerized Planar Motion Carriage) of ocean engineering basin in KRISO (Korea Research Institute of Ships and Ocean engineering). Total 6 degrees-of-freedom motion were fixed by two points supporting captive model test device, which is specially designed for this test. This system estimates 6 degrees-of-freedom forces and moments through 12 strain gauge signals. Mapping matrix from strain gauge signals to 6 degrees-of-freedom forces and moments was derived by a well-organized calibration test. Static drift test was conducted in calm sea and in regular waves with various wave conditions. Hydrodynamic coefficients related to drift angle were extracted for each wave conditions, and the effect of waves on course stability was analyzed.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.185-200
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• 2023

The Korea Augmentation Satellite System (KASS) is the first satellite navigation enhancement system in Korea developed in compliance with international standards. Technologies accumulated during the development process should be spread to industries such as academia and serve as the basis for developing the domestic satellite navigation field. This paper introduces the development process from design to implementation, testing, and verification of KASS control systems (KCS). First, development standards, milestones, requirements, and interface standards are presented as KCS development methods, and major functional design, physical design, and hardware/software implementation are described based on the allocated requirements. Subsequently, the verification environment, procedures, and results of the development product are covered and the developed operational and maintenance procedures are described. In addition, based on the experience gained through the development, suggestions were made for beneficial technology development and organization when promoting satellite navigation projects in the future. Since this work has important historical value for the development of domestic satellite navigation, it is expected that the development results will be shared with academia and industry in the future and be used as basic data for similar development.