• Journal of Power Electronics
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• 제18권1호
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• pp.34-44
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• 2018

This paper presents a pulse-width adjustment (PWA) strategy for a novel bidirectional DC-DC boost converter to improve the performance of the dynamic inductor current response. This novel converter consists of three main components: a full-bridge converter (FBC), a high-frequency isolated transformer with large leakage inductance, and a three-level voltage-doubler rectifier (VDR). A number of scholars have analyzed the principles, such as the soft-switching performance and high-efficiency characteristic, of this converter based on pulse-width modulation plus phase-shift (PPS) control. It turns out that this converter is suitable for energy storage applications and exhibits good performance. However, the dynamic inductor current response processes of control variable adjustment is not analyzed in this converter. In fact, dc component may occur in the inductor current during its dynamic response process, which can influence the stability and reliability of the converter system. The dynamic responses under different operating modes of a conventional feedforward control are discussed in this paper. And a PWA strategy is proposed to enhance the dynamic inductor current response performance of the converter. This paper gives a detailed design and implementation of the PWA strategy. The proposed strategy is verified through a series of simulation and experimental results.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1445-1452
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• 2016

Recently Mobile Software Applications are developed in various languages and stored in App Store. App Users selectively use appropriate apps for the owned hardware. In other words, it depends on the kinds of operating systems of the apps whether to use or not to use the applications in various languages. The apps should be differently implemented according to the kind of the user's device, though they provide the same functions. To solve these problems, it is necessary to define an independent function specification method which is not dependent to a specific system environment. In this paper, the Mobile Application Developing Framework is suggested, which incorporates all of the development process. Standardized models are proposed which can be used in the analysis and design steps. In implementation phase, a technique for cross framework design is suggested so as to implement a platform dependent mobile app.

• 한국산학기술학회논문지
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• 제5권5호
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• pp.413-420
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• 2004

본 연구에서는 인버터를 구동하는 용도의 직류전원장치에 대한 제어 알고리즘 개발을 목표로 하고 있으며, 구동과 회생기능을 갖는 전압형 PWM 컨버터에서 운전시 전원의 불평형을 보상하는 제어방법을 제안하고자 한다. 이를 위해 전력회생기능을 갖는 정류기에 대하여 기존 다이오드 및 SCR을 이용한 정류방식과의 비교를 통해 본 제어방식의 우수성을 시뮬레이션과 실험을 통해 입증하고자 한다. 전력변환기가 항상 평형상태를 유지하기 위해 전류제어 루프에 의하여 불평형 상태를 보상하는 방법을 사용하였으며, 통상적으로 전력변환기의 구성시 각상의 리액턴스가 같지 않은 누설변압기 등의 사용을 가능하게 하므로 제안된 전력변환기의 리액턴스가 불평형상태가 되어도 운전시 항상 평형상태로 유지되어 시스템을 안정적으로 구동 시킬 수 있는 제어기법의 설계를 통해 어떤 환경에서도 장치의 안정된 구동특성을 확인하고자 하였다.

• 한국컴퓨터정보학회논문지
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• 제13권5호
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• pp.171-177
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• 2008

소프트웨어 개발 방법론 중 소프트웨어를 부품화한 후에 이를 조려하거나 합성하여 새로운 정보시스템을 개발하는 CBD방법론이 널리 연구되어 왔다. 그러나 CBD방법론은 잦은 요구사항의 변경과 유연한 프로세스를 가져야 하는 모바일 환경에서 한계를 가진다. 본 논문에서는 이러한 한계를 해결하기 위해 UML컴포넌트에 기반한 개선된 모바일 개발 프로세스를 제안한다. 제안 기법은 빠른 변화가 발생하는 소규모의 모바일 시스템을 개발하기 위해 세 단계의 다이어그램으로 구성된 간소화된 프로세스를 가진다 제안된 개발 프로세스를 모바일 뱅킹 업무에 적용하여 요구사항의 변경에 빠르게 대응하고 유연한 개발이 가능함을 보인다.

• 정보보호학회논문지
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• 제29권2호
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• pp.465-472
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• 2019

최근 몇 년 사이에 사이버 공격의 보편화로, 사이버 공간내의 공격을 사이버전이라는 일종의 전쟁으로 간주하고 있다. 그러나 사이버전은 직접적인 피해 식별이 불가하여 공격에 대한 아군의 피해 파악이 어렵다. 사이버전에서 발생할 수 있는 공격에 대한 피해를 효과적으로 평가하기 위해, 본 논문은 MOCE(Measure of Cyber Effectiveness) 산출 식을 활용하여 사이버 공격에 대한 피해를 산출할 수 있는 DEVSim++ 기반의 사이버전의 피해 평가 시뮬레이션을 제시한다. 또한 사이버 지휘 통제 단계에서 지휘관의 판단을 돕기 위해, 공격 분류별 피해 받은 개체 수를 벤 다이어그램 형태로 표현하여 결과를 직관적으로 가시화한다.

• 방송공학회논문지
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• 제24권3호
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• pp.485-494
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• 2019

주파수 변조 방식의 방송 주파수에 동조되는 안테나와 Realtek 사(社)의 RTL2832 칩을 이용하는 디지털 TV용 튜너와 아날로그-디지털 변환기로 구성되는 universal serial bus (USB) 동글을 이용하여 스테레오 주파수 변조 방송의 실시간 수신기를 컴퓨터의 소프트웨어로 구현한다. 아날로그 방송 신호가 USB 동글에서 디지털 신호로 변환되고 이진 데이터를 컴퓨터에서 매트랩 및 파이선 프로그래밍 언어의 신호처리 기법을 이용하여 저역 통과 필터, 대역 통과 필터, 주파수 판별기, 양측파대 진폭 복조, 위상 고정 루프. 샘플링 변환, 디앰퍼시스 등의 기능 블록을 설계한다. 최종적으로 수신기의 실시간 구현을 위하여 파이선 및 C++로 구성되는 그누라디오 (GNU Radio)를 이용하여 수신기 알고리즘을 소프트웨어로 구현한다.

• 한국산업융합학회 논문집
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• 제24권3호
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• pp.253-260
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• 2021

The implementation of subsea separation and liquid boosting is becoming a common development scheme for the exploration of deep water fields. Subsea separation is an attractive and economic solution to develop deep offshore fields producing fluid without hydrate or wax. A subsea separator can avoid or simplifying costly surface platforms of floating vessels, as well as being an efficient tool to enhance hydrocarbon production. Subsea separation system should be reliable to ensure successful operation in a wide range of 3-phase flow regime. In this study, multiphase flow characteristics inside in-line type subsea separation system are investigated for the design of subsea separation system.

• International journal of advanced smart convergence
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• 제10권1호
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• pp.24-37
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• 2021

China's "One Belt and One Road" initiative has brought multiple opportunities to the development of tourism in Guangdong, Guangxi and Hainan provinces and the implementation of the Beibu Gulf Urban Agglomeration Development Plan hasset clear goalsforfurther accelerating the coordinated development, in-depth cooperation of the three. This study takes the Beibu Gulf Urban Agglomeration as the research object and utilized the data envelopment analysis (DEA) procedure to estimate the technical efficiency, pure technical efficiency, and scale efficiency scores for each city and Malmquist index was subsequently used to analyze dynamically, then tries to offer an adequate inclusion of sustainable factors in overall tourism development efficiency results through the detection and estimation of potential sources of efficiency. In order to complete the task, data collection was focused on Guangdong, Guangxi and Hainan provinces of China over the period from 2016 to 2018. The results in the first phase show relatively high efficiency scores, particularly in the case of the Beibu Gulf Urban Agglomeration and with room for improvement in the case of other cities of Guangdong, Guangxi and Hainan provinces. The second stage results present several aspects that should be carefully considered in order to analysis tourism efficiency of the Beibu Gulf Urban Agglomerations vertically according to the changes of the frontier.

• 농촌계획
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• 제28권2호
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• pp.51-59
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• 2022

The purpose of this study is to provide a plan to promote the use of life SOC facilities by analyzing the factors affecting utilization of life SOC facilities established as part of the rural center revitalization project. To this end, we selected Seongjeon-myeon, Gangjin-gun where the rural center revitalization project was implemented, conducted a survey on residents while analyzing the project details, and analyzed the results. This study revealed that the residents with a cognitive level for the rural center revitalization project and life SOC tended to more actively use the life SOC facilities. Therefore, to boost residents' use of the life SOC facilities, it is necessary to promote their understanding of and interest in the rural center revitalization project in the project implementation phase and have them be sufficiently aware of the facilities by operating pilot programs for residents in each facility and holding local events and festivals. This study will lay a steppingstone for active resident use of life SOC facilities established in rural centers and provide basic data for further research.

• Asia Marketing Journal
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• 제14권3호
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• pp.153-167
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• 2012

KB Kookmin Card has separated as an independent corporation from KB Kookmin Bank Credit Card Business Group on March, 2011. Ever since, KB Kookmin Card worked to build its own brand identity. The strategic preparation and conscientious implementations made KB Kookmin Card position in consumer's mind with a strong and unique brand image. Its new brand image was rooted in the inherited strengths of reliable and sincere image. However, it faced the challenge to compete in credit card industry in which most competitors had an advanced and sophisticated image. The strengths of KB Kookmin Card were also at the same time their limitations. KB Kookmin Card took a strategy that strengthened the strengths and improved the weaknesses. It focused on the core competence of being a people's sincere life supporter that helps people make savings from everyday events to make a good sum rather than being a lump sum benefit. The brand introduction strategy was implemented in 2011. The implementation focused on the activities that made internal as well as external customers be aware of the brand. Communication programs using a variety of media were executed to attain this goal. In 2012, second phase communication programs were introduced to elaborate the newly established brand image. It introduced many extended products as well as accessory programs which targeted the segments. Also, various CSR activities in many social domains helped consumers and the public to consider KB Kookmin Card an authentic, caring, trustworthy, and consistently-developing supporter in their everyday lives.