• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.337-340
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• 2009

In general, channel information of received DTV signal analyzed based on symbol timing clock with only In-phase information in DTV receiver. This paper presents technical requirements of channel analysis system for DTV reception signal. In order to meet such requirements and measure more accurate magnitude and phase of channel information, compensation method for the quadrature information from measured in-phase data is proposed. The proposed channel analysis system is implemented with a commercial DTV chipset and provides fast data analysis with good connectivity with field test vehicles. Computer simulation and laboratory test results are provided to figure out the performance of the proposed channel analysis system for DTV signal.

• 한국항공운항학회지
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• 제17권3호
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• pp.40-50
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• 2009

Avionics system's function for an air transport mission is analysed. The starting point for designing a Avionics system is a clear understanding of the mission requirements and the requirement allocation by the top level aircraft system. Therefore, the analysis begins by making a top-down analysis to the aircraft missions. The baseline mission is divided into segments, and each segment is subjected to a detailed analysis to establish the requirements for the Avionics system. Special attention is given to capture the key aspects of interfaces, and to incorporate them into the design.

• 한국컴퓨터정보학회논문지
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• 제21권11호
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• pp.79-83
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• 2016

In this paper, we define four levels of analysis, design, implementation, and testing of the configuration of the development phase by S/W development life cycle. In particular, it dealt with the stage of the analysis phase to prepare an information system developed intensively. Details of the derivation of the information security requirements, it can be seen that comes from the perspective of confidentiality, integrity, availability and accountability, etc. It dealt with from the first manifestations of the projects planning to final planning to establish information security in activities of the Information Security requirements. As an example exhibited by assessing the information security analysis phase activities of S corporations, it can be seen that the improved sales rise in information security activities.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1635-1643
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• 2022

STPA (System-Theoretic Process Analysis) is a widely used safety analysis technique to identify UCAs (Unsafe Control Actions) resulting in potential losses. It is totally dependent on the experience and ability of analysts to construct an information model called Control Structures, upon which analysts try to identify unsafe controls between system components. This paper proposes a formal approach to support the manual identification of UCAs, effectively and systematically. It allows analysts to mechanically extract Process Model, an important element that makes up the Control Structures, from a formal requirements specification for a software controller. It then concisely constructs the contents of Context Tables, from which analysts can identify all relevant UCAs effectively, using a software fault tree analysis technique. The case study with a preliminary version of a Korean nuclear reactor protections system shows the proposed approach's effectiveness and applicability.

• International Journal of Aeronautical and Space Sciences
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• 제17권2호
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• pp.268-283
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• 2016

Aircraft manufacturing companies have to consider multiple derivatives to satisfy various market requirements. They modify or extend an existing aircraft to meet new market demands while keeping the development time and cost to a minimum. Many researchers have studied the derivative design process, but these research efforts consider baseline and derivative designs together, while using the whole set of design variables. Therefore, an efficient process that can reduce cost and time for aircraft derivative design is needed. In this research, a more efficient design process is proposed which obtains global changes from local changes in aircraft design in order to develop aircraft derivatives efficiently. Sensitivity analysis was introduced to remove unnecessary design variables that have a low impact on the objective function. This prevented wasting computational effort and time on low priority variables for design requirements and objectives. Additionally, uncertainty from the fidelity of analysis tools was considered in design optimization to increase the probability of optimization results. The Reliability Based Design Optimization (RBDO) and Possibility Based Design Optimization (PBDO) methods were proposed to handle the uncertainty in aircraft conceptual design optimization. In this paper, Collaborative Optimization (CO) based framework with RBDO and PBDO was implemented to consider uncertainty. The proposed method was applied for civil jet aircraft derivative design that increases cruise range and the number of passengers. The proposed process provided deterministic design optimization, RBDO, and PBDO results for given requirements.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.417-421
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• 2006

ICAO defines performance requirements of navigation system such as accuracy, integrity, continuity and availability. The integrity is most significant performance requirement in aviation where safety of life is crucial. Many researches on this topic anticipate that GPS with SBAS or Galileo can meet APV requirements and GPS with GBAS or Galileo with GBAS will meet CAT II and III requirements. These performance expectations are based on global analysis. In this paper regional integrity analysis in Korea using various combinations of modernized GPS, Galileo and SBAS is given. The simulation results show that CAT I requirement can be met using modernized GPS and Galileo alone, however, CAT II and III are not met even augmenting SBAS because of VPL. A more efficient augmentation such as GBAS which can reduce VPL dramatically is required to meet CAT II and III in Korean region.

• Journal of Power Electronics
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• 제15권2호
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• pp.530-543
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• 2015

Air-cooling method is adopted on the basis of the requirements for the thermal stability and convenient field use of an electrical source transmitter. The power losses of the transmitter are determined after calculating the losses of the alternating current (AC)-direct current (DC) power supply, the constant-current circuit, and the output circuit. According to the analysis of the characteristics of a heat sink with striped fins and a fan, the engineering calculation expression of the Nusselt number and the design process for air-cooled dissipation are proposed. Experimental results verify that the error between calculated and measured values of the transmitter losses is 12.2%, which meets the error design requirements of less than 25%. Steady-state average temperature rise of the heat sink of the AC-DC power supply is $22^{\circ}C$, which meets the design requirements of a temperature rise between $20^{\circ}C$ and $40^{\circ}C$. The transmitter has favorable thermal stability with 40 kW output power.

• Journal of Information Processing Systems
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• 제20권1호
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• pp.38-52
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• 2024

The 5G is the 5th generation mobile network that provides enhanced mobile broadband, ultra-reliable & low latency communications, and massive machine-type communications. New services can be provided through multi-access edge computing, network function virtualization, and network slicing, which are key technologies in 5G mobile communication. However, these new technologies provide new attack paths and threats. In this paper, we analyzed the overall threats of 5G mobile communication through a literature review. First, defines 5G mobile communication, analyzes its features and technology architecture, and summarizes possible security issues. Addition, it presents security threats from the perspective of user devices, radio access network, multi-access edge computing, and core networks that constitute 5G mobile communication. After that, security requirements for threat factors were derived through literature analysis. The purpose of this study is to conduct a fundamental analysis to examine and assess the overall threat factors associated with 5G mobile communication. Through this, it will be possible to protect the information and assets of individuals and organizations that use 5G mobile communication technology, respond to various threat situations, and increase the overall level of 5G security.

• 한국정보시스템학회지:정보시스템연구
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• 제27권1호
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• pp.43-65
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• 2018

Purpose The emergence of mobile applications has simplified our life in various ways. Regarding tourism activities, mobile applications are already efficient in providing personalized tourism related information and are very much effective in booking hotels, flights, etc. However, there are very few studies on classifying the actual service requirements and improving the customer satisfaction in mobile tourism applications. The purpose of this study is to implement a practical mobile tourism application. To serve the purpose, we classify and categorize the service requirement of mobile tourism applications in Korea. We employed Kano model and analytic hierarchy process (AHP). Specifically, we conducted a focus group study to find out the service requirements in mobile tourism applications. Design/methodology/approach The data for this study were collected from Koreans and Foreigners who has the experience using mobile tourism applications. Participants needed to be familiar with mobile tourism applications because such users may be more aware of the mobile tourism applications services. We analyzed 147 valid data using Kano model and conducted AHP analysis on five experts in the field of tourism using Expert Choice software. Findings In this paper, we identified the 17 service quality requirements in the mobile tourism applications. The results reveal that the service requirement such as Geo-location map, Multilingual option, Compatibility with different operating systems were unavoidable service, absent of such requirements leads to the dissatisfaction. Based on the results of the integrated application of both Kano model and AHP analysis, this study provide specific implications for improving the service quality of the mobile tourism applications in Korea.

• 융합보안논문지
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• 제15권5호
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• pp.29-35
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• 2015

네트워크 보안 암호화 방식은 단대단 암호화 방식과 링크간 암호화 방식으로 구분된다. 네트워크 환경에서 보안 품질요구사항 이란 시스템이 제공해야 할 보안품질 속성의 수준이다. 품질속성은 관찰할 수 있고 측정할 수 있어야 하기 때문에 품질 요구사항도 가능하면 정확한 수치로 제시되어야 한다. 품질 요구사항이 정의되어야 구체적 품질 관리 목표가 설정된다. 품질속성에서 기능적 요구사항은 암호화를 통해 얻을 수 있는 서비스 기능에 대한 요구조건이다. 비 기능적 요구사항은 암호화를 통해 얻을 수 있는 서비스의 품질 요구조건이다. 본 연구에서 제안하는 암호화 품질 평가체계는 기능적 요구사항과 비 기능적 요구사항 2개영역으로 도출한다. 평가지표의 동일 분류내 척도를 산출한 후 각 지표의 품질 측정값에 대한 연계지표를 작성한다. 품질평가 매트릭스는 품질측정 값에 대한 연계지표 분석용 2-factor 평가로서 기능적 요구사항과 비기능적 요구사항 두 가지 기준으로 평균치를 산출 한다. 산출결과는 추세를 분석하여 종합 평가가 가능하도록 한다. 이와같은 방식을 적용할 경우 네트워크 보안 암호화 품질평가의 기반을 구성할 수 있다.