• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.89-100
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• 2016

Given the unpredictability of the space environment, satellite communications are manually performed by exchanging telecommands and telemetry. Ground support for orbiting satellites is given only during limited periods of ground antenna visibility, which can result in conflicts when multiple satellites are present. This problem can be regarded as a scheduling problem of allocating antenna support (task) to limited visibility (resource). To mitigate unforeseen errors and costs associated with manual scheduling and mission planning, we propose a novel method based on a genetic algorithm to solve the ground support problem of multiple satellites and antennae with visibility conflicts. Numerous scheduling parameters, including user priority, emergency, profit, contact interval, support time, remaining resource, are considered to provide maximum benefit to users and real applications. The modeling and formulae are developed in accordance with the characteristics of satellite communication. To validate the proposed algorithm, 20 satellites and 3 ground antennae in the Korean peninsula are assumed and modeled using the satellite tool kit (STK). The proposed algorithm is applied to two operation modes: (i) telemetry, tracking, and command and (ii) payload. The results of the present study show near-optimal scheduling in both operation modes and demonstrate the applicability of the proposed algorithm to actual mission control systems.

• 한국멀티미디어학회논문지
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• 제17권6호
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• pp.706-715
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• 2014

It is used to lead to serious structural vulnerability of the system security of security-critical system when we have quickly developed software system according to urgent release schedule without appropriate security planning, management, and assurance processes. The Data Set and Provider of DataSnap, which is a middleware of Delphi XE2 of the Embarcadero Technologies Co., certainly help to develop an easy and fast-paced procedure, but it is difficult to apply security program and vulnerable to control software system security when the connection structure Database-DataSnap server-SQL Connection-SQL Data set-Provider is applied. This is due to that all kinds of information of Provider are exposed on the moment when DataSnap Server Port is sure to malicious attackers. This exposure becomes a window capable of running SQL Command. Thus, it should not be used Data Set and Provider in the DataSnap Server in consideration of all aspects of security management. In this paper, we study on the verification of the security vulnerabilities for Client and Server DataSnap in Dlephi XE2, and we propose a secure coding method to improve security vulnerability in the DataSnap server system.

• Journal of Advanced Marine Engineering and Technology
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• 제32권7호
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• pp.1061-1067
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• 2008

Direct Torque Control[DTC] and Vector Control are the two schemes developed for high performance induction motor drives. DTC based induction motors are being increasingly used in various industrial applications. DTC offers fast torque response and better speed control with lesser hardware and processing costs as compared to vector controlled drives. However, conventional DTC suffers from high torque ripple, current harmonics and low performance during torque transients. In this paper a new Direct Torque Control[DTC] method of induction motor is presented. In comparison with the conventional DTC method, the PWM technique is applied to proposed control method. In this method, decoupling mechanism is not required and the torque, the flux magnitude are under control using PI controllers and generating the voltage command for inverter control. Therefore torque and speed ripple could be reduced in comparison with the conventional switching table DTC.

• The Journal of Asian Finance, Economics and Business
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• 제7권4호
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• pp.213-221
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• 2020

This study examines the relationship between brand authenticity, brand equity, and customer satisfaction. A total of 263 participants participated in this study. Participants rated a set of three brands: Apple, Starbuck, and Nike. Each participant rated the extent to which the items described his or her authenticity with the brands listed, the equity of the brands listed, and feelings of satisfaction toward the brands. This study employs confirmatory factor analysis and structural equation modeling. The results indicate that 1) brand authenticity positively relates to brand equity, and 2) brand authenticity effects to customer satisfaction. The findings suggest that marketers can use the brand authenticity for assessment, planning, and tracking purposes to understand the authenticity of their brands for their customers. Products of authenticity brand are better liked, viewed as higher quality, offer greater value and are more likely to be purchased than less authenticity brand. They can command a significant price premium. The findings provide useful support and evidence for brand management, as well as companies in other developing countries, to engage more in brand practices as a core element of their strategic and brand management. This means that managers should work to increase perceptions of authenticity for their offerings.

• 대한안전경영과학회지
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• 제5권4호
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• pp.97-106
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• 2003

At present, tendency of ERP(Enterprise Resource Planning) enterprises is that many ERP enterprises from abroad are rushing into capture of small and medium enterprises at home actively. SAP Korea and Korean Oracle have already showed their new product targeting domestic market of small or medium standing enterprise, and more, even MS(Micro Soft) also rushes into this market in earnest. The domestic business circle of ERP should prepare countermeasure by raising the perfection of product and having good command of minute marketing strategy to survive from aggressive strategy of SMB market. In addition, about the computerization of main affairs of business, ordering developing process was general that developing staffs analysed the affairs of each department that needed computerization and construct according to the operation process by using different tools, but condition is changing that businesses themselves are purchasing business application package from expert soft program enterprise and construct. Therefore, in this study, I try to grasp the problem of management, and define a new process that can help for more efficient management by making it an object producing and management module of enterprise 'K' that is one of domestic small and medium enterprise and that is operating ERP at present. As well, through the analysis of affair related producing, we are aiming to prepare for establishment of target, its range, and making the standard of result evaluation.

• 한국군사과학기술학회지
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• 제26권3호
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• pp.281-301
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• 2023

The shipboard combat system is a key system for naval combat that supports a command and control process cycle consisting of Detect - Control - Engage in real time to ensure ship viability and conduct combat missions. Modern combat systems were developed on the basis of Open Architecture(OA) to maximize acceptance of latest technology and interoperability between systems, and actively introduced the COTS(Commercial-of-the-shelf). However, as a result of that, vulnerabilities inherent in COTS SW and HW also occurred in the combat system. The importance of combat system cybersecurity is being emphasized but cybersecurity research reflecting the characteristics of the combat system is still lacking in Korea. Therefore, in this paper, we systematically identify combat system threats by applying Data Flow Diagram, Microsoft STRIDE threat modelling methodology. The threats were analyzed using the Attack Tree & Misuse case. Finally we derived the applicable security requirements which can be used at stages of planning and designing combat system and verified security requirements through NIST 800-53 security control items.

• 대한토목학회논문집
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• 제33권1호
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• pp.363-375
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• 2013

오늘날 숙련된 굴삭기 운전자의 부족현상은 갈수록 심화되고 있으며, 자원개발 및 새로운 생활공간 창출 등을 목적으로 운전자가 접근하기 어려운 극한환경에서 토공작업의 필요성이 증가함에 따라 전 세계적으로 토공완전자동화를 위한 무인화 굴삭로봇 개발의 노력이 경주되고 있다. 국내에서도 지난 2006년 말부터 국토해양부 건설기술혁신사업의 일환으로 '지능형 굴삭시스템' 연구단을 구성하여 연구를 지속하고 있다. 본 논문에서는 지능형 굴삭시스템의 작업계획생성시스템이 갖추어야 할 세부요소기술 중, 굴착작업의 위치, 범위, 목표, 순차 등 굴삭로봇의 운용단위 작업명령정보를 생성하기 위한 정보화단위를 제공하는 로컬영역설계모듈의 연구개발내용에 대하여 설명한다. 로컬영역의 설계는 굴삭로봇의 제원, 작업메커니즘, 휴리스틱 및 구조적안전성 등 여러 영향요소가 고려되어야 안전하고 효율적인 굴착작업을 보장하는 작업계획을 생성할 수 있다. 따라서 로컬영역의 설계요소를 분석하기 위하여 현장조사를 통한 개념적 설계를 수행하고, 상세설계를 통해 설계변수를 도출하였으며, 휴리스틱 및 구조적 해석요건을 만족하도록 설계내용을 정량화하였다. 마지막으로 로컬영역설계모듈을 개발하기 위한 알고리즘을 구축하고, 개발된 모듈을 검증하였다.

• 한국위성정보통신학회논문지
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• 제6권1호
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• pp.37-44
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• 2011

2010년 6월 26일에 발사된 통신해양기상위성(천리안)은 Ka-대역 위성통신, 정지궤도 해양관측, 그리고 기상관측을 위한 탑재체를 가지고 있다. 정지궤도상의 위성을 효과적으로 운용하기 위해서 위성 임무운영 개념을 정립하여 이를 위성관제시스템의 개발 초기 단계부터 적용하였다. 천리안 위성의 임무운영은 일별, 주별, 월별 그리고 계절별 운영으로 구분된다. 위성의 일별운영은 임무계획, 명령계획 및 전송, 원격측정 데이터 처리 및 분석, 위성 거리측정 및 궤도결정, 위성의 궤도 및 이벤트 예측, 그리고 휠 오프로딩 파라미터 계산으로 구분된다. 위성의 주별 운영으로는 화요일에 남북방향 위치유지조정, 목요일에 동서방향 위치유지조정으로 구분된다. 월별운영으로는 위성의 온보드 오실레이터를 갱신하기 위한 비행역학 파라미터 계산과 위성으로의 전송이 수행되며 계절별 운영으로 봄과 가을에는 지구가 태양을 가리는 식에 관련된 위성운영을 수행한다. 이 논문에서는 통신해양기상위성이 발사된 후 약 3개월에 걸친 궤도 내 시험 기간 중에 이루어진 위성관제시스템의 주요 기능들에 대한 운영검증을 기술한다. 이 기간 중에 위성관제시스템의 대부분 기능이 성공적으로 검증되었으며 천리안 위성관제시스템은 위성의 설계 수명기간인 7년 또는 위성이 수명을 다하는 그 이후까지 계속 사용될 예정이다.

• 한국정보시스템학회지:정보시스템연구
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• 제19권4호
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• pp.25-49
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• 2010

As companies introduced ERP (Enterprise Resource Planning) systems since the middle of 1990s, the databases of the companies has become centralized and gigantic. The companies are now developing data-mining based applications on those centralized and gigantic databases for knowledge management. Almost of them are using $Pro^*C$/C++, a embedded SQL programming language, and it's because the $Pro^*C$/C++ is independent of platforms and also fast. However, they suffer from difficulties in development and maintenance due to the characteristics of corporate databases which have intrinsically large number of tables and fields. The purpose of this research is to design and implement a methodology which makes it easier to develop and maintain embedded SQL applications based on relational databases. Firstly, this article analyzes the syntax of $Pro^*C$/C++ and addresses the concept of repetition and duplication which causes the difficulties in development and maintenance of corporate information systems. Then, this article suggests a management architecture of source codes and databases in which a preprocessor generates $Pro^*C$/C++ source codes by referring a DB table specification, which would solve the problem of repetition and duplication. Moreover, this article also suggests another architecture of DB administration in which the preprocessor generates DB administration commands by referring the same table specification, which would solve the problem of repetition and duplication again. The preprocessor, named $PrePro^*C$, has been developed under the UNIX command-line prompt environment to preprocess $Pro^*C$/C++ source codes and SQL administration commands, and is under update to be used in another DB interface environment like ODBC and JDBC, too.

• 한국위성정보통신학회논문지
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• 제1권2호
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• pp.16-24
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• 2006

복합임무를 갖는 정지궤도 위성인 통신해양기상위성은 항공우주연구원, 전자통신연구원, 해양연구원, 기상청과 국내외 기업이 공동으로 개발을 수행하고 있다. 통신해양기상위성의 주 계약자는 EADS Astrium이며 전자통신연구원은 정보통신부의 재원으로 Ka 대역 통신탑재체와 지상 관제시스템을 개발하고 있다. 통신해양기상위성의 관제시스템은 궤도상의 위성을 감시하고 제어할 수 있는 유일한 시스템이다. 통신해양기상위성에 탑재되어 있는 세개의 탑재체와 위성체 버스에 대한 임무운용을 위해서 지상 관제시스템은 원격측정 신호의 수신과 처리, 위성의 추적과 거리측정, 원격명력의 생성 및 송출, 위성의 임무계획, 비행역학데이터 처리, 그리고 위성 시뮬레이션을 수행한다. 이와 같은 기능을 적절히 할당해서 통신해양기상위성의 관제시스템은 TTC, 실시간운영, 임무계획, 비행역학, 그리고 위성시뮬레이터와 같은 5개의 서브시스템으로 구성되었다. 본 논문에서는 통신해양기상위성 관제시스템을 구성하는 5 개의 서브시스템에 대한 기능 설계와 인터페이스를 기술한다.