• 전기전자학회논문지
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• 제21권4호
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• pp.331-337
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• 2017

본 논문에서는 20MHz 대역폭, 저잡음, 저전력의 3차 저역 통과 시그마-델타 모듈레이터를 개발한다. 본 시스템의 대역폭은 LTE 및 그 외 다른 광대역 무선통신 표준을 만족할 수 있다. Feed-forward 구조의 3차 저역 통과 필터를 통해 저전력 및 저복잡도를 실현한다. 개발된 시스템은 빠른 데이터 변환을 실현하기 위해 3bit-flash 타입의 양자화 회로를 사용하였다. Current-steering DAC의 경우 추가적인 회로 없이 높은 정확도와 낮은 전력 소모의 이유로 고안되었다. DAC의 입력 전압이 변할 경우 생기는 glitch들을 없애기 위해 cross-coupled 트랜시스터를 사용하여 glitch 상쇄(cancellation)를 실현하였다. 개발된 시스템은 32.65mW의 저전력 구현과 함께 65.9dB의 peak SNDR, 20MHz의 대역폭을 실현한다. 600mVp-p의 입력 two-tone 신호 입력 인가후의 IM3는 69dBc를 실현하였으며 TSMC의 0.18-um CMOS 공정을 이용하여 설계되었다.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.208-221
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• 2019

The inference for this research was concentrated on client's data protection in cloud computing i.e. data storages protection problems and how to limit unauthenticated access to info by developing access control model then accessible preparations were introduce after that an access control model was recommend. Cloud computing might refer as technology base on internet, having share, adaptable authority that might be utilized as organization by clients. Compositely cloud computing is software's and hardware's are conveying by internet as a service. It is a remarkable technology get well known because of minimal efforts, adaptability and versatility according to client's necessity. Regardless its prevalence large administration, propositions are reluctant to proceed onward cloud computing because of protection problems, particularly client's info protection. Management have communicated worries overs info protection as their classified and delicate info should be put away by specialist management at any areas all around. Several access models were accessible, yet those models do not satisfy the protection obligations as per services producers and cloud is always under assaults of hackers and data integrity, accessibility and protection were traded off. This research presented a model keep in aspect the requirement of services producers that upgrading the info protection in items of integrity, accessibility and security. The developed model helped the reluctant clients to effectively choosing to move on cloud while considerate the uncertainty related with cloud computing.

• 대한조선학회논문집
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• 제52권2호
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• pp.97-103
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• 2015

This paper has focused on the middle term process planning around quays based on the prefixed long-term plan of the product mixed ships. Recently, the order rate of high add-value ships in domestic shipyards has been sharply increased and the spending time at quays is accordingly on an increasing trend. For proper and practical process planning related to quays, it has to be closely connected with a long-term plan and product calendar, erection network and result of ship allocation around quays. Moreover, it is also required to include the integrated consideration of the whole process of a yard, each ship, and each team respectively. The most distinguishing feature of this study is that it would run on the ship allocation simulator and GIS framework in order not to be limited to the specific one yard and the readers can figure out the optimization formulation containing the work load leveling and a different approach from PERT/CPM. The proposed approach reflected all requirements from the department of process planning and management in a shipyard, and the analysis of the results has explained its performance of the optimization result with the examples of total 43 ships under construction from 2008 to 2013.

• 한국철도학회논문집
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• 제19권2호
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• pp.159-169
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• 2016

국내 철도의 관제는 신호, 전철전력, 통신, 설비 등 분야별로 고유한 시스템으로 구축되어 있다. 각 분야의 관제시스템은 현장 설비의 센싱 데이터를 중앙관제로 전송하는 매체와 프로토콜이 서로 상이하다. 안전관제시스템은 각 분야의 안전에 관련된 데이터를 모두 수집하여 철도 사고를 예측하고 예방하는 것을 목적으로 하며 표준 프로토콜을 사용한다. 안전관련 데이터는 기존 관제시스템의 현장 데이터 전송장치에서 데이터 수집이 필요하다. 이때 중요한 점은 기존 관제시스템 통신에 영향 없이 데이터를 수집하는 방법이다. 본 논문에서는 데이터를 수집하는 방법으로 네트워크 트래픽 감시나 보안용으로 사용되는 스니핑을 이용한다. 스니핑 장치를 사용할 때 야기되는 문제점을 설명하고 해결 방법으로 패킷 변환 노드를 제안하였다. 추가적으로 프로토타입을 개발하여 기능과 성능 테스트를 수행하여 S/W아키텍처와 패킷 변환 과정에 대해 검증하였다.

• KIEAE Journal
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• 제10권1호
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• pp.3-10
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• 2010

Riverside forests make a river bank stable because trees of them hold together the stone and soil by roots and decrease the speed of running fluid by trunks. So they become known to have positive effects on flood prevention. So This study will be a basic study to preserve and restore of riverside forests. The goal of this study is to classify types of Han riverside forests between Yangpyeng and Yeoju gun. and find out sites of planting. Results of this study can be summarized as follows; The evaluation indicators were set up based on literature review and site survey. Two indicator categories were developed: natural environment and human environment. And they were divided into 5 sub-categories for calculating weights. As for the major indicator categories, the weighted index of natural environment is at 0.5. And the weighted index of human environment is at 0.5 followed by access at 0.15, the range of user at 0.15, cultivated land at 0.1 and legislation at 0.1. This study selected 53 sites for riverside forests planting. They were classified with types of bank(11), level-upped riverside(32), island(10). The amount of the length of 11 bank types is 23,050m, the area of 32 level-upped riverside types is $4,490,000m^2$ and the area of 10 island types is $4,590,000m^2$. After the evaluation of 53 riverside forests, this study selected 12 sites of riverside forests. They were two bank types, nine level-upped riverside types, and one island type. Rebuilding riverside forests are to accomplish the green network which links and divides region. It will be one of the best ecological methods to construct friendly environmental region.

• KIEAE Journal
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• 제12권3호
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• pp.3-10
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• 2012

The purpose of this study is to seek a planning approach for children's museum within Korean context that promotes community participation. A literature review method and a field survey method were used. Literature reviews on community participation paradigm, residents' participation and donation networks in community regeneration processes, and finally on case studies on children's museum in Korea were carried out. Through the field survey on Chicago Children's Museum(CCM) located in downtown Chicago, its role was identified as networking systems of community participation and donation and was verified as a socio-physical base for vitalizing donation culture that is an active and a leading community participation method. As a result, CCM has engaged many partnerships with city organizations and local schools to provide diverse and unique programs that are not only targeted to children but also parents, teachers and visitors. Also, an evolution of CCM through various types of donations and community participation was delineated. CCM was found successfully in restoring community spirit and vitalizing economical growth where it once was a decayed city area. Rather than focusing on descriptive technique of typical children's museum, this study explored how community fabric is made and acted out, through rethinking community participation's value, and how it can influence a physical space. CCM, as a good example of community participatory museum, the results can be used as a reference in planning and directing community participation based children's museums in Korea. It is significant to shed light on children's museum as an opportunity of social space which can empower community.

• 한국통신학회논문지
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• 제32권2B호
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• pp.83-89
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• 2007

본 논문에서는 OLT의 중앙집중 제어에 의한 대역폭 중재 없이 ONU간의 분산적인 동적 대역폭 할당을 이룰 수 있는 파워 검출 기반의 TDM-PON의 MAC 프로토콜을 제안하였다. 기존의 E-PON에서 사용하는 소프트웨어 기반의 DBA 방식과 달리, 제안된 방식은 하드웨어 기반의 파워 검출을 활용하여 동적 대역폭 할당 알고리즘을 수행함으로써 간단하고 빠르며 비용효과 측면에서 장점을 가진다. 제안된 가입자 망의 성능 평가는 수식적 분석과 컴퓨터 시뮬레이션을 통하여 수행하였으며, 특히 다양한 트래픽 모델 환경에서 제안된 방식의 성능향상 정도를 기존 E-PON들과 비교 및 분석하였다.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권6호
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• pp.264-273
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• 2006

In this paper, we propose a new architecture of Self-Organizing Fuzzy Polynomial Neural Networks (SOFPNN) by means of consecutive optimization and also discuss its comprehensive design methodology involving mechanisms of genetic optimization. The network is based on a structurally as well as parametrically optimized fuzzy polynomial neurons (FPNs) conducted with the aid of information granulation and genetic algorithms. In structurally identification of FPN, the design procedure applied in the construction of each layer of a SOFPNN deals with its structural optimization involving the selection of preferred nodes (or FPNs) with specific local characteristics and addresses specific aspects of parametric optimization. In addition, the fuzzy rules used in the networks exploit the notion of information granules defined over system's variables and formed through the process of information granulation. That is, we determine the initial location (apexes) of membership functions and initial values of polynomial function being used in the premised and consequence part of the fuzzy rules respectively. This granulation is realized with the aid of the hard c-menas clustering method (HCM). For the parametric identification, we obtained the effective model that the axes of MFs are identified by GA to reflect characteristic of given data. Especially, the genetically dynamic search method is introduced in the identification of parameter. It helps lead to rapidly optimal convergence over a limited region or a boundary condition. To evaluate the performance of the proposed model, the model is experimented with using two time series data(gas furnace process, nonlinear system data, and NOx process data).

• 정보보호학회논문지
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• 제30권5호
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• pp.771-780
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• 2020

양자키분배(QKD)는 양자컴퓨터의 위협으로부터 안전하게 비밀키를 나누어 갖는 키공유 프로토콜 중 하나이다. 일반적으로 QKD 장치에 연결되는 암호장치는 경합조건 발생과 구현의 복잡성 때문에 송신자 또는 수신자의 역할을 설치할 때부터 적용한다. 기존 QKD 시스템은 링크용 암호장치에 주로 적용되었기 때문에 암호장치의 송·수신자 역할을 고정하여도 문제가 없었다. 암호장치와 QKD 장치가 공급하는 양자키의 종속성을 제거하여, QKD 네트워크로 유연하게 확장할 수 있는 새로운 QKD 시스템 및 프로토콜을 제안하였다. 기존 QKD 시스템에서는 암호장치가 요청하는 비밀키를 양자키로 직접 분배하였으나, 제안한 QKD 시스템에서는 난수로 생성한 비밀키를 암호장치에 분배한다. 두 QKD 노드 사이에서 미리 나누어 가진 송신용 및 수신용 양자키를 이용하여 비밀키를 암호화하고 전달하는 구조를 제안하였다. 제안한 QKD 시스템은 QKD 장치들 사이에서 공유한 양자키의 의존성을 제거하여 암호장치의 고정된 송·수신자 역할이 필요 없다.

• 한국통신학회논문지
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• 제36권6B호
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• pp.583-591
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• 2011

본 논문에서는 기존 G-PON(Gigabit Passive Optical Network) 링크에 RSOA(Reflective Semiconductor Optical Amplifier) 기반 DWDM-PON(Dense Wavelength Division Multiplexing-PON) 기술과 O/E/O 변환 방식의 RE(Reach Extender) 기술을 적용하여 전송거리와 링크 용량 그리고 분기수를 증가시킬 수 있는 2.5 Gbps 하이브리드 PON 링크의 구조를 제안한다. RSOA 기반 DWDM-PON 기술은 간선 중계링크에 적용되어, 기존 G-PON 보다 최대 32배의 링크 전송용량을 제공할 수 있다. RE 기술은 원격노드에서 GTC(GPON Transmission Convergence) 프레임의 재 변조를 통해 DWDM-PON과 G-PON 사이의 파장변환 기능을 제공하며, 상향 프레임의 수신을 위한 버스트 모드 리셋 신호를 제공한다. 본 논문에서 제안된 하이브리드 PON은 상용 G-PON 시스템을 사용하여 WDM 신호 파장 당 최대 60 km의 전송거리와 128분기를 제공할 수 있다.