• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.504-527
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• 2015

Underwater wireless sensor networks (UWSNs) are similar to the terrestrial sensor networks. Nevertheless, there are different characteristics among them such as low battery power, limited bandwidth and high variable propagation delay. One of the common major problems in UWSNs is determining an efficient and reliable routing between the source node and the destination node. Therefore, researchers tend to design efficient protocols with consideration of the different characteristics of underwater communication. Furthermore, many routing protocols have been proposed and these protocols may be classified as location-based and location-free routing protocols. Pressure-based routing protocols are a subcategory of the location-free routing protocols. This paper focuses on reviewing the pressure-based routing protocols that may further be classified into non-void avoidance protocols and void avoidance protocols. Moreover, non-void avoidance protocols have been classified into single factor based and multi factor based routing protocols. Finally, this paper provides a comparison between these protocols based on their features, performance and simulation parameters and the paper concludes with some future works on which further study can be conducted.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.233-236
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• 2001

We have designed and fabricated ASK modulator MMIC operating at 5.8GHz for OBE used in AGPS (Automatic Gate Passing System). ASK modulator MMIC was designed to apply a sing1e supply voltage of 3V to the drain in order to decrease ACP (Adjacent Channel Power). The measurement result of this chip exhibits on/off characteristic over 30dB. The design parameters are optimized through ADS simulation tool. The layouts and fabrication o( ASK Modulator MMIC were designed and fabricated by using ETRI 0.5${\mu}{\textrm}{m}$ MESFET library. The chip sizes were 1mm $\times$1mm. The performance analysis of the implemented ASK Modulator based on the design parameters is accomplished.

• 한국정보과학회논문지:시스템및이론
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• 제32권11_12호
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• pp.566-577
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• 2005

유비쿼터스 컴퓨팅은 네트워크로 상호연결된 프로세서로 구성되며, 하나 이상의 컴퓨터로 이루어진다. 따라서 한 시스템의 단일 컴포넌트 뿐만 아니라 전체 시스템의 가용도를 유지할 수 있어야만 한다. 본 연구에서는 사람의 간섭을 최소화하면서 예기치 못한 결함이 발생하여도 서비스를 지속적으로 제공할 수 있는 능력을 시스템에 부여하기 위한 오토노믹 자가 관리 기법을 제안하고 설계한다. 또한 시스템 로그 분석 결과를 통한 서비스 부하 모델을 근간으로 제안한 메커니즘의 효율성을 검증한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권7호
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• pp.2815-2839
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• 2020

In a cloud computing paradigm, allocation of various virtualized ICT resources is a complex problem due to the presence of heterogeneous application (MapReduce, content delivery and networks web applications) workloads having contentious allocation requirements in terms of ICT resource capacities (resource utilization, execution time, response time, etc.). This task of resource allocation becomes more challenging due to finite available resources and increasing consumer demands. Therefore, many unique models and techniques have been proposed to allocate resources efficiently. However, there is no published research available in this domain that clearly address this research problem and provides research taxonomy for classification of resource allocation techniques including strategic, target resources, optimization, scheduling and power. Hence, the main aim of this paper is to identify open challenges faced by the cloud service provider related to allocation of resource such as servers, storage and networks in cloud computing. More than 70 articles, between year 2007 and 2020, related to resource allocation in cloud computing have been shortlisted through a structured mechanism and are reviewed under clearly defined objectives. Lastly, the evolution of research in resource allocation techniques has also been discussed along with salient future directions in this area.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.65-65
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• 2003

After many genome projects, algorithms and software to process explosively growing biological information have been developed. To process huge amount of biological information, high performance computing equipments are essential. If we use the remote resources such as computing power, storages etc., through a Grid to share the resources in the Internet environment, we will be able to obtain great efficiency to process data at a low cost. Here we present the performance improvement of the protein secondary structure prediction (PSIPred) by using the Grid platform, distributing protein sequence data on the Grid where each computer node analyzes its own part of protein sequence data to speed up the structure prediction. On the Grid, genome scale secondary structure prediction for Mycoplasma genitalium, Escherichia coli, Helicobacter pylori, Saccharomyces cerevisiae and Caenorhabditis slogans were performed and analyzed by a statistical way to show the protein structural deviation and comparison between the genomes. Experimental results show that the Grid is a viable platform to speed up the protein structure prediction and from the predicted structures.

• 전기학회논문지
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• 제65권3호
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• pp.388-396
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• 2016

Through the correspondence works with international electrotechnical vocabulary(IEV) in the smart grid field and power information technology field, we analyzed cases for discussion of terms and definitions in the IEV and then proposed an advanced procedure and computing system for standardization of International Electronical Committee(IEC) terminologies. The standardization procedure consists of processes for existing terminology, new terminology and correspondent terminology which have different structures. An example of the standardization work of correspondent terminology is given. The standardization computing system are based on the process for terminology extraction, terminology verification and terminology management which could provide the Wikipedia type terminology search function. In order to prevent that there exist multiple terminologies in IEV, the database search system is needed to be developed. We proposed the 'IEV_Term_Search' program which is the database search system. Terminology standardization of different technical committees(TC) and completion of the IEV to promote cooperation between TC 1 and the TCs must be followed by revision and standardization using the standardization computing system.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.658-661
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• 2005

클라이언트/서버 기반 방식의 컨텐츠 전송 시스템은 서버로 작업요청이 많아질 경우에는 서버에 처리부하가 집중되는 병목현상으로 인하여 시스템이 마비 되는 취약점을 가지고 있다. 그러나 인터넷 사용자의 폭발적인 증가와 컨텐츠 품질 향상 요구로 인하여 서버의 증설만으로는 한계에 이르렀다. 그러므로 이러한 문제점들을 개선하기 위해 P2P 기반 컴퓨팅방식을 사용한다. 본 논문에서는 컴퓨팅 자원의 공유를 목적으로 하는 P2P 컴퓨팅 환경에서 유휴 컴퓨팅 자원을 이용하여 교육 콘텐츠 전송 시스템을 설계하고 구현한다. 제안된 시스템은 인터넷 전송뿐만 아니라 위성 채널을 통해 콘텐츠를 전송할 수 있도록 시스템을 구현하고, 실시간 강의와 비실시간 강의의 콘텐츠를 모두 전송하도록 설계한다.

• International Journal of Computer Science & Network Security
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• 제21권2호
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• pp.158-170
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• 2021

Virtualization technologies are being adopted and broadly utilized in many fields and at different levels. In cloud computing, achieving load balancing across large distributed virtual machines is considered a complex optimization problem with an essential importance in cloud computing systems and data centers as the overloading or underloading of tasks on VMs may cause multiple issues in the cloud system like longer execution time, machine failure, high power consumption, etc. Therefore, load balancing mechanism is an important aspect in cloud computing that assist in overcoming different performance issues. In this research, we propose a new approach that combines the advantages of different task allocation algorithms like Round robin algorithm, and Random allocation with different threshold techniques like the VM utilization and the number of allocation counts using least connection mechanism. We performed extensive simulations and experiments that augment different scheduling policies to overcome the resource utilization problem without compromising other performance measures like makespan and execution time of the tasks. The proposed system provided better results compared to the original round robin as it takes into consideration the dynamic state of the system.

• 반도체디스플레이기술학회지
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• 제23권1호
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• pp.1-6
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• 2024

Recently, artificial neural networks have been playing a crucial role and advancing across various fields. Artificial neural networks are typically categorized into feedforward neural networks and recurrent neural networks. However, feedforward neural networks are primarily used for processing static spatial patterns such as image recognition and object detection. They are not suitable for handling temporal signals. Recurrent neural networks, on the other hand, face the challenges of complex training procedures and requiring significant computational power. In this paper, we propose memristors suitable for an advanced form of recurrent neural networks called reservoir computing systems, utilizing a mask processor. Using the characteristic equations of Ti/TiOx/TaOy/Pt, Pt/TiOx/Pt, and Ag/ZnO-NW/Pt memristors, we generated current-voltage curves to verify their memristive behavior through the confirmation of hysteresis. Subsequently, we trained and inferred reservoir computing systems using these memristors with the NIST TI-46 database. Among these systems, the accuracy of the reservoir computing system based on Ti/TiOx/TaOy/Pt memristors reached 99%, confirming the Ti/TiOx/TaOy/Pt memristor structure's suitability for inferring speech recognition tasks.

• 디지털융복합연구
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• 제9권1호
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• pp.153-164
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• 2011

급신장하고 있는 소셜컴퓨팅은 사회 전반에 걸쳐 그 파급력과 영향력을 확대하고 있는데, 최근 정치 분야로도 영역을 넓혀가고 있다. 한편 시민들의 정치적 참여 추세는 '스마트시민정당'이란 혁신적 아이디어를 낳았고, 이는 정당의 개방성과 수용성을 요구하기에 이르렀다. 스마트시민정당은 기존의 ICT(Information Communication Technology)는 물론 소셜컴퓨팅을 기반으로 하는 원활한 소통구조를 요구한다. 즉 스마트시민정당을 구현하기 위해서는 소셜컴퓨팅 환경이 갖추어진 컴퓨팅 프레임워크가 필요한 것이다. 이에 본 연구는 스마트시민정당의 기술적 기반으로서 소셜컴퓨팅 프레임워크를 제안하는 데에 목적이 있다. 이를 위해 본 연구는 제2절에서 소셜웹의 부상, 공공(정치)부문에서의 ICT와 혁신, 소셜컴퓨팅의 개념과 영향 등을 다룰 것이다. 또한 제 3절에서는 문헌 연구와 전문가 심층면담 을 통해 스마트시민정당의 개념과 특성 및 서비스를 살펴본 다음, 이를 지원하기 위한 쇼셜컴퓨팅 프레임워크 구조와 구성요소 및 서비스 기능에 대해 다룰 것이다.