• 대한임베디드공학회논문지
• /
• 제17권6호
• /
• pp.375-382
• /
• 2022

This paper proposes a multi-core cooperative computing structure considering the heterogeneous features of automotive embedded on-chip software. The automotive embedded software has the heterogeneous execution flow properties for various hardware drives. Software developed with a homogeneous execution flow without considering these properties will incur inefficient overhead due to core latency and load. The proposed method was evaluated on an target board on which a automotive MCU (micro-controller unit) with built-in multi-cores was mounted. We demonstrate an overhead reduction when software including common embedded system tasks, such as ADC sampling, DSP operations, and communication interfaces, are implemented in a heterogeneous execution flow. When we used the proposed method, embedded software was able to take advantage of idle states that occur between heterogeneous tasks to make efficient use of the resources on the board. As a result of the experiments, the power consumption of the board decreased by 42.11% compared to the baseline. Furthermore, the time required to process the same amount of sampling data was reduced by 27.09%. Experimental results validate the efficiency of the proposed multi-core cooperative heterogeneous embedded software execution technique.

• International Journal of Computer Science & Network Security
• /
• 제23권3호
• /
• pp.94-100
• /
• 2023

The primary goal of any communication spacecraft is to provide communication in variety of frequency bands based on mission requirements within the Indian mainland. Some of the spacecrafts operating in S-band utilizes a 6m or larger aperture Unfurlable Antenna (UFA for S-band links and provides coverage through five or more S-band spot beams over Indian mainland area. The Unfurlable antenna is larger than the satellite and so the antenna is stowed during launch. Upon reaching the orbit, the antenna is deployed using motors. The deployment status of any deployment mechanism will be monitored and verified by the telemetered values of micro-switch position before the start of deployment, during the deployment and after the completion of the total mechanism. In addition to these micro switches, a camera onboard will be used for capturing still images during primary and secondary deployments of UFA. The proposed checkout system is realized for validating the performance of the onboard camera as part of Integrated Spacecraft Testing (IST) conducted during payload checkout operations. It is designed for acquiring the payload data of onboard camera in real-time, followed by archiving, processing and generation of images in near real-time. This paper presents the architecture, design and implementation features of the acquisition, processing and Image generation system for Camera onboard spacecraft. Subsequently this system can be deployed in missions wherever similar requirement is envisaged.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2021년도 춘계학술대회
• /
• pp.574-576
• /
• 2021

대규모 운영시스템이나 확장성을 고려한 시스템을 구성할 때 마이크로서비스 기법을 도입하는 것이 필요하다. 카프카는 pub/sub 모델을 가지는 메시지 큐로서 분산환경에 잘 적용되는 특징을 가지며, 다양한 데이터 소스를 활용할 수 있다는 점에서 마이크로서비스에 적합하다. 이 논문에서는 아파치의 카프카를 이용한 교육동영상 공유 서비스의 데이터 공유 방안을 제안하고자 한다. 제안하는 시스템은 교육 동영상 공유서비스이 다양한 데이터를 공유하기 위해 카프카 클러스터를 구축하며, 아울러 교육동영상의 유사도를 기반으로 하는 추천 시스템과 연계하기 위해 스파크 클러스터를 이용한다. 그리고 파일, RDBMS의 DB등과 같은 다양한 데이터 소스를 공유하는 방안을 제시한다.

• Advances in nano research
• /
• 제14권5호
• /
• pp.443-450
• /
• 2023

Carbon nanotubes (CNTs) have received increased interest in reinforcing research for polymer matrix composites due to their exceptional mechanical characteristics. Its high surface area/volume ratio and aspect ratio enable polymer-based composites to make the most of its features. This study focuses on the experimental tensile testing and fabrication of carbon nanotube reinforced composite (CNTRC) beams, exploring various micromechanical models. By examining the performance of these models alongside experimental results, the research aims to better understand and optimize the mechanical properties of CNTRC materials. Tensile properties of neat epoxy and 0.3%; 0.4% and 0.5% by CNT reinforced laminated single layer (0°/90°) carbon fiber composite beams were investigated. The composite plates were produced in accordance with ASTM D7264 standard. The tensile test was performed in order to see the mechanical properties of the composite beams. The results showed that the optimum amount of CNT was 0.3% based on the tensile capacity. The capacity was significantly reduced when 0.4% CNT was utilized. Moreover, the experimental results are compared with Finite Element Models using ABAQUS. Hashin Failure Criteria was utilized to predict the tensile capacity. Good conformance was observed between experimental and numerical models. More importantly is that Young' Moduli of the specimens is compared with the prediction Halpin-Tsai and Mixture-Rule. Although Halpin-Tsai can accurately predict the Young's Moduli of the specimens, the accuracy of Mixture-Rule was significantly low.

• Educational Technology International
• /
• 제17권1호
• /
• pp.87-116
• /
• 2016

In this research, we designed a teacher professional development (PD) program where a small group of mathematics teachers could share, reflect on, and discuss their pedagogical knowledge and practices of ICT-integrated lessons, using a video annotation tool called DIVER. The main purposes of this paper are both micro and macro: to examine how the teachers were engaged in the meaning-making process in a video-based PD (micro); and to derive implications about how to design effective video-based teacher PD programs toward a teacher community of practices (macro). To examine teachers' meaning-making in the PD sessions, discourse data from a series of 10 meetings was segmented into idea units and coded to identify discourse patterns, focusing on (a) participation levels, (b) conversation topics, and (c) conversation depth. Regarding the affordance of DIVER, discourse patterns of two meetings, before and after individual annotation with DIVER were compared through qualitative vignette analysis. Overall, we found that the teacher discourse shifted the focus from surface features to deeper pedagogical issues as the PD sessions progressed. In particular, the annotation function in DIVER afforded the teachers to exercise descriptive analyses of video clips in a flexible manner, thereby helping them cognitively prepared to take interpretative and evaluative stances in face-to-face discussions with colleagues. In conclusion, deriving from our research experiences, we discuss the possibilities and challenges of designing video-based teacher PD in a school context.

• 한국전자파학회논문지
• /
• 제29권7호
• /
• pp.550-559
• /
• 2018

본 논문은 딥뉴럴네트워크(deep neural network: DNN)를 이용해 사람 걸음 및 배경잡음원에 의해 발생한 마이크로 도플러 신호를 탐지 및 분류 처리하는 연구를 제안한다. 기존 분류처리 연구는 경험 및 통계적인 방법을 통해 분류기 성능에 직접적으로 영향을 미치는 의미있는 특징을 추출하기 위한 복잡한 과정을 포함한다. 그러나 딥뉴럴네트워크는 다수의 레이어 층을 단계적으로 통과하는 과정을 통해 점진적으로 특징을 재구성 및 생성하므로, 별도의 특징 추출과정을 생략할 수 있으며, 자연스럽게 네트워크상에서 특징을 생성할 수 있는 이점이 있다. 따라서 본 논문에서는 마이크로 도플러 신호 인식을 위한 딥뉴럴네트워크 효과성 입증을 위해, 이진분류기와 다층클래스 분류기를 다층퍼셉트론과 딥뉴럴네트워크를 통해 설계하고 비교분석한다. 실험 결과, 다층퍼셉트론은 이진분류기의 경우 테스트세트에 대한 분류 정확도가 90.3 %로 측정되었고, 다층클래스 분류기의 경우 테스트세트에 대한 분류정확도가 86.1 %로 측정되었다. 딥뉴럴네트워크는 이진분류기의 경우 테스트세트에 대한 분류 정확도가 97.3 %로 측정되었고, 다층클래스 분류기의 경우 테스트세트에 대한 분류정확도가 96.1 %로 측정되었다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권18호
• /
• pp.7645-7652
• /
• 2014

Neuroblastoma (NB), the most common extracranial solid tumor, accounts for 10% of childhood cancer. To date, scientists have gained quite a lot of knowledge about microRNAs (miRNAs) and their genes in NB. Discovering inner regulation networks, however, still presents problems. Our study was focused on determining differentially-expressed miRNAs, their target genes and transcription factors (TFs) which exert profound influence on the pathogenesis of NB. Here we constructed three regulatory networks: differentially-expressed, related and global. We compared and analyzed the differences between the three networks to distinguish key pathways and significant nodes. Certain pathways demonstrated specific features. The differentially-expressed network consists of already identified differentially-expressed genes, miRNAs and their host genes. With this network, we can clearly see how pathways of differentially expressed genes, differentially expressed miRNAs and TFs affect on the progression of NB. MYCN, for example, which is a mutated gene of NB, is targeted by hsa-miR-29a and hsa-miR-34a, and regulates another eight differentially-expressed miRNAs that target genes VEGFA, BCL2, REL2 and so on. Further related genes and miRNAs were obtained to construct the related network and it was observed that a miRNA and its target gene exhibit special features. Hsa-miR-34a, for example, targets gene MYC, which regulates hsa-miR-34a in turn. This forms a self-adaption association. TFs like MYC and PTEN having six types of adjacent nodes and other classes of TFs investigated really can help to demonstrate that TFs affect pathways through expressions of significant miRNAs involved in the pathogenesis of NB. The present study providing comprehensive data partially reveals the mechanism of NB and should facilitate future studies to gain more significant and related data results for NB.

• 한국전산구조공학회논문집
• /
• 제34권1호
• /
• pp.51-58
• /
• 2021

본 논문에서는 Needle-punched C/SiC 복합재료 해석을 위한 효율적인 멀티스케일 해석기법을 소개한다. 기존 Needle-punching으로 인해 복잡한 미소구조를 갖는 NP 복합재료는 기존의 제안된 복합재료 멀티스케일 기법으로 물성을 계산하는 것은 한계가 있어 왔다. 이를 극복하기 위해 micro-CT 이미지 촬영을 통해 NP 복합재료의 미소구조를 면밀히 파악할 수 있었고, 이미지 프로세싱을 바탕으로 실제구조와 직접적으로 대응할 수 있는 3D high fidelity 모델을 구축하였다. 또한 유한요소해석에 맞춰 요소크기를 조절할 수 있는 sub-region processing 소개를 바탕으로 효율적인 유한요소해석을 수행하였다. NP 복합재료의 미소구조 거동뿐만 아니라, macro-scale 구조해석의 적용을 위해 subcell 모델링을 제안하였다. Needle-punching에 의한 Z축 NP 섬유의 규칙적인 간격을 이용하여 모델링을 수행할 수 있었다. 제안한 두 종류의 모델은 균질화 기법을 이용하여 등가거동 및 등가물성을 파악하였으며, 추가적인 실험 결과와의 비교를 통해 검증을 수행하였다.

• 한국동물위생학회지
• /
• 제43권3호
• /
• pp.129-137
• /
• 2020

In this study, we applied biodegradable drug delivery carries (BDDC) for food-and-mouth (FMD) vaccination. After FMD vaccination using BDDC, we estimated the percentage inhibition (PI) of antibody, decomposed patterns, and histopathologic features of BDDC. PI of antibody was higher than 50 at two weeks after injection and sustained positive PI until 10 weeks after injection. BBDC injection group showed significantly an increased pattern of blood monocyte at two and three weeks after injection. According to the Micro CT, micro-cracks were observed at two weeks after injection and the morphology of BDDC was lost at four weeks after injection. For histopathological examination, acute inflammation with neutrophil infiltration and micro-metallic residues were observed around BDDC until four weeks after injection and inflammatory responses gradually decreased at 10 weeks. Based on our experiment, BDDC is considered as an alternative way to vaccine injection for veterinary applications. Our study can be used as basic data for the drug delivery system using biodegradable metals in the future.

• 한국결정성장학회지
• /
• 제19권2호
• /
• pp.90-94
• /
• 2009

Mong Hsu rubies from Myanmar were heat treated in oxidizing(oxygen) atmosphere at $1650^{\circ}C$ for 1 hour. The investigations of the micro-structural defects in the samples before and after heat treatment have been carried out by the variety of analysis techniques of FTIR, UV-VIS-NIR and SEM-EDS. It was found that after heat treatment the dark blue cores region were disappeared and turned to orange red color with the presence of the dense cloudy brownish colored tiny particles in and near former blue zoning. As-received ruby samples only revealed the presence of FTIR absorption peaks of diaspore, boehmite and O-H stretching, at 1986, 2115 and $3078/3319\;cm^{-1}$ respectively. The UV-VIS-NIR absorption of as-received and heat treated ruby samples similarly showed peaks at 405, 554 and 693 nm associated with $Cr^{3+}$, but for the same samples, the absorption peak of heat-treated ruby samples at 693 nm was somewhat stronger than that of the untreated ruby samples. Especially the presence of $Cr^{3+}$ peaks at 659 and 675 nm was found obviously in as-received ruby samples only. The SEM-EDS investigation disclosed the micro-porous defect structures commonly related to the core regions of the untreated ruby samples, which after heat treatment in an oxidizing environment those defect features have been dissolved into the host phase resulting in the lightening or disappearance of the dark coloration of ruby core.