• Smart Media Journal
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• v.11 no.4
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• pp.9-18
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• 2022

Recently, research and system using AI is rapidly increasing in various fields. Smart farm using artificial intelligence and information communication technology is also being studied in agriculture. In addition, data-based precision agriculture is being commercialized by convergence various advanced technology such as autonomous driving, satellites, and big data. In Korea, the number of commercialization cases of facility agriculture among smart agriculture is increasing. However, research and investment are being biased in the field of facility agriculture. The gap between research and investment in facility agriculture and open-air agriculture continues to increase. The fields of fruit trees and plant factories have low research and investment. There is a problem that the big data collection and utilization system is insufficient. In this paper, we are proposed the system for determining the fruit tree growth stage using a deep learning-based object detection model. The system was proposed as a hybrid app for use in agricultural sites. In addition, we are implemented an object detection function for the fruit tree growth stage determine.

• KNOM Review
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• v.24 no.2
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• pp.24-34
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• 2021

Service providers using edge computing provide a high level of service. As a result, devices store important information in inner storage and have become a target of the latest cyberattacks, which are more difficult to detect. Although experts use a security system such as intrusion detection systems, the existing intrusion systems have low detection accuracy. Therefore, in this paper, we proposed a machine learning model for more accurate intrusion detections of devices in edge computing. The proposed model is a hybrid model that combines a stacked sparse autoencoder (SSAE) and a convolutional neural network (CNN) to extract important feature vectors from the input data using sparsity constraints. To find the optimal model, we compared and analyzed the performance as adjusting the sparsity coefficient of SSAE. As a result, the model showed the highest accuracy as a 96.9% using the sparsity constraints. Therefore, the model showed the highest performance when model trains only important features.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.65-73
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• 2016

Peer-to-Peer (P2P) systems with super-peer overlay networks show combined advantages of both hybrid and pure P2P systems. Super-peer is a special peer acting as a server to a cluster of generic peers. Organizing a super-peer network is one of important issues for P2P systems with super-peer networks. Conventional P2P systems are based on two-level hierarchies of peers. One is a layer for generic peers and the other is for super-peers. And it is usual that super-peer networks have forms of random graphs. However, for accommodating a large-scale collection of generic peers, the super-peer network has also to be extended. In this paper, we propose a scheme of hierarchically constructing super-peer networks for large-scale P2P systems. At first, a two-level tree, called a simple super-peer network, is proposed, and then a scheme of generalizing and then extending the simple super-peer network to multi-level super-peer network is presented to construct a large-scale super-peer network. We call it an extended super-peer network. The simple super-peer network has several good features, but due to the fixed number of levels, it may have a scalability problem. Thus, it is extended to k-level tree of a super-peer network, called extended super-peer network. It shows good scalability and easy management of generic peers for large scale P2P system.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.274-276
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• 2002

Ad Hoc망은 전형적인 무선 네트워킹과는 다른 새로운 무선 네트워킹 파라다임으로써 기존 유선 망의 하부 구조에 의존하지 않고 이동 호스트들로만 구성된 네트워크이다. Ad Hoc망에서 통신을 하기 위해서는 출발지 노드에서 목적지 노드까지 데이터 전송을 위한 라우팅에 관한 문제이다. Ad Hoc망에서는 모든 단말기의 위치변화가 가능하기 때문에 경로설정에 어려움이 따른다. 노드간에 정보를 보내고자 할 때 노드가 인접한 상태가 아니면 정보를 직접 보낼 수 없고 여러 중간 노드들을 거쳐서 정보를 보내는 다중-홉 라우팅 방식을 사용해야 한다. 따라서 중간 노드들은 패킷 라우터의 역할을 해야하는데 무선 통신자체가 좁은 대역폭과 한정된 채널을 가지고 전송 범위가 제한되는 문제가 있다. 또한 노드자체의 이동성과 전력 소모 등으로 인한 이탈은 망 위상을 수시로 변화시키므로 노드간에 정보를 전송하는데 가장 좋은 경로는 수시로 변경될 수 있으므로 많은 어려움이 따르게 된다. 본 논문에서는 이러한 문제의 해결방안으로 경로유지 과정에서 Ad Hoc망 내의 노드들은 이동성의 특성으로 인해 현재 사용되는 경로 보다 더 짧고 효율적인 경로가 발생하고 중간 노드가 이동 될 때 새로운 경로로 갱신하여 솔기없는 최적의 경로를 유지할 수 있는 방법을 제안한다. 제안 방법은 ZRP의 IERP에서 감청모드를 통하여 사용중인 경로보다 최적의 경로를 감지하여 새로운 경로로 갱신하는 방법과 중간 노드가 이동하여 경로가 깨진 경우 부분적으로 경로를 복구하는 방법을 제시하여 항상 최적화된 경로를 유지함으로써 Ad Hoc망의 위상변화에 대한 적응성을 높일 수 있도록 한다.기반으로 하는 교육용 애플리케이션 개발의 용이성의 증대를 기대할 수 있으며, 모델의 재사용성을 보장할 수 있다. 제안한다.수행하였다. 분석에서는 제품의 효율성뿐만 아니라 보안성을 중요하게 생각하였으며, 앞으로 보안 관련 소프트웨어 개발에 사용될 수 있는 도구들이 가이드 라인에 대한 정보를 제공한다.용할 수 있는지 세부 설계를 제시한다.다.으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.21-28
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• 2015

In the semi-conductor process, a simulation process is performed to detect defects by analyzing the behavior of the impurity through the physical quantity calculation of the inner element. In order to perform the simulation, Finite-Difference Time-Domain(FDTD) algorithm is used. The improvement of semiconductor which is composed of nanoscale elements, the size of simulation is getting bigger. Problems that a processor such as CPU or GPU cannot perform the simulation due to the massive size of matrix or a computer consist of multiple processors cannot handle a massive FDTD may come up. For those problems, studies are performed with parallel/distributed computing. However, in the past, only single type of processor was used. In GPU's case, it performs fast, but at the same time, it has limited memory. On the other hand, in CPU, it performs slower than that of GPU. To solve the problem, we implemented a computing model that can handle any FDTD simulation regardless of size on the cluster which consist of heterogeneous processors. We tested the simulation on processors using MPI libraries which is based on 'point to point' communication and verified that it operates correctly regardless of the number of node and type. Also, we analyzed the performance by measuring the total execution time and specific time for the simulation on each test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.706-715
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• 2004

In this paper, to decide the watermark embedding positions and embed the watermark we use the subband tee structure which is presented in the wavelet domain and the edge information in the spatial domain. The significant frequency region is estimated by the subband searching from the higher frequency subband to the lower frequency subband. LH1 subband which has the higher frequency in tree structure of the wavelet domain is divided into 4${\times}$4 submatrices, and the threshold which is used in the watermark embedding is obtained by the blockmatrix which is consists by the average of 4${\times}$4 submatrices. Also the watermark embedding position, Keymap is generated by the blockmatrix for the energy distribution in the frequency domain and the edge information in the spatial domain. The watermark is embedded into the wavelet coefficients using the Keymap and the random sequence generated by LFSR(Linear feedback shift register). Finally after the inverse wavelet transform the watermark embedded image is obtained. the proposed watermarking algorithm showed PSNR over 2㏈ and had the higher results from 2％ to 8％ in the comparison with the previous research for the attack such as the JPEG compression and the general image processing just like blurring, sharpening and gaussian noise.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.768-779
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• 2017

Recently, the great number of mobile devices causes excessive data/control traffic problems in the centralized LTE/EPC network and such dramatically increased traffic is emerging as a critical issue. In the Centralized Mobility Management (CMM) based LTE/EPC network, the Packet Data Network Gateway (P-GW) plays the centralized mobility anchor role and it accommodates most of data traffic. To solve this problem, the IETF has proposed the Distributed Mobility Management (DMM) scheme, but it has only focused on the data traffic load balancing and could not solve the control traffic overload problem. In this paper, therefore, we propose a new SDN based hybrid CMM/DMM Mobility Management (C-DMM) architecture based on Packet Network Edge Gateway (P-EGW), and introduce a selection scheme between CMM and DMM according to a device's mobility and the number of PDN connections. In order to prove the efficiency of the proposed architecture and scheme, we compare the data traffic processing load and the control traffic processing load over each scheme by emulating them in the ONOS controller and the Mininet environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.477-480
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• 2002

Si-O-C(-H) thin film with a tow dielectric constant were deposited on a P-type Si(100) substrate by an inductively coupled plasma chemical vapor deposition (ICPCVD). Bis-trimethylsilymethane (BTMSM, H$_{9}$C$_3$-Si-CH$_2$-Si-C$_3$H$_{9}$) and oxygen gas were used as Precursor. Hybrid type Si-O-C(-H) thin films with organic material have been generated many voids after annealing. Consequently, the Si-O-C(-H) films can be made a low dielectric material by the effect of void. The surface characterization of Si-O-C(-H) thin films were performed by SEM(scanning electron microscope). The characteristic analysis of Si-O-C(-H) thin films were performed by X-ray photoelectron spectroscopy (XPS).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.401-404
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• 2015

This paper proposes a high-performance in-loop filter in HEVC(High Efficiency Video Coding) encoder for Ultra HD video processing in real time. HEVC uses in-loop filter consisting of deblocking filter and SAO(Sample Adaptive Offset) to solve the problems of quantization error which causes image degradation. In the proposed in-loop filter encoder hardware architecture, the deblocking filter and SAO has a 2-level hybrid pipeline structure based on the $32{\times}32CTU$ to reduce the execution time. The deblocking filter is performed by 6-stage pipeline structure, and it supports minimization of memory access and simplification of reference memory structure using proposed efficient filtering order. Also The SAO is implemented by 2-statge pipeline for pixel classification and applying SAO parameters and it uses two three-layered parallel buffers to simplify pixel processing and reduce operation cycle. The proposed in-loop filter encoder architecture is designed by Verilog HDL, and implemented by 205K logic gates in TSMC 0.13um process. At 110MHz, the proposed in-loop filter encoder can support 4K Ultra HD video encoding at 30fps in realtime.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.5
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• pp.499-506
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• 2019

This paper is concerned with the operating stability of 7kW inverter using SIC hybrid module and verifies the validity of the simulation results by comparing the result of the loss equation and the simulation result, Simulation results using Si module and SiC hybrid module are compared to compare switch loss and diode loss. Through the loss equation calculation, the conduction loss of SiC Hybrid module is 168W, switching loss is 9.3W, diode loss is 10.5nW, When compared with the simulation results, similar values were shown. As a result of comparing the simulation results of the Si module and the SiC Hybrid module, The total device loss of the Si module was 246.2W, and the total device loss of the SiC Hybrid module was 189.9W. The loss difference was 56.3W, which was about 0.8W. thereby verifying the reverse recovery characteristics of the SiC SBD. In addition, temperature saturation test was conducted to confirm the stability of SiC Hybrid module and Si module under high temperature saturation, In the case of the Si module, the output power was stopped at 4kW, and the SiC Hybrid module was confirmed to operate at 7kW. Based on this, an efficiency graph and a temperature graph are presented, and the Si module is graphed up to 4kW and the SiC Hybrid module is graphed up to 7kW.