• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.4
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• pp.34-40
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• 2013

Attitude command response type required for enhanced handling qualities of helicopter can be implemented by mechanical automatic flight control system with SAS actuators which have limited authorities. However, the early saturation of SAS actuator hinders the helicopter from following the attitude command for large stick command. Auto-trim controller can delay SAS actuator's saturation by utilizing trim actuators and allows the attitude command response type for larger stick command. This paper describes the control law for limited authority system of helicopter with auto-trim. Limited authority system is applied to BO-105 linear dynamic model and simulation is performed along with handling quality analysis.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.1
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• pp.67-73
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• 2015

The previous limited authority system capable of implementing attitude command response type and translational command response type by operating SAS actuator has the problem of early saturation of SAS actuator since SAS actuator should compensate the mechanical linkage displacement caused by control sick movement. In this paper, a limited authority system where flight control computer receives the command from the control stick which is not connected to the mechanical linkage is described. In this system the compensation by the SAS actuator is not necessary and SAS actuator saturate later. SAS actuator saturation problem can be further relaxed by using the trim actuator. This new limited authority system is applied to BO-105 model, simulation is performed for the doublet input and pirouette maneuver is also simulated and analyzed.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.871-874
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• 2003

본 논문은 LDAP 클라이언트와 서버사이에서의 상호운용성 시험을 위한 시험도구 구현에 대한 것이다. 여러 벤더에 의해 구현된 LDAP 제품들을 업무에 적응하기 위해서는 상호간의 접속 운용이 가능한지를 시험하기 위한 것으로 표준적합성 시험과 함께 상호운용성 시험이 선행 되어야 한다. 이러한 시험을 위한 시험도구로 이미 구현된 것이 있으나, 이들은 OS 에 따른 설치 시 제약조건이 많으며, 시험 실행방법의 어려움과, 시험 시 시험항목 및 LDAP 서버에 저장된 데이터가 한정되어 불편한 점이 있다. 이를 보완하기 위해 BLITS를 기반으로 한 OS의 제약이 적고, 사용자가 시험 항목을 수정 가능한 시험도구를 구현하였다. 구현한 시험도구의 타당성 검증을 위해 두 개의 LDAP 서버를 대상으로 하여 실제 상호운용성 시험을 수행 하였다. 시험 결과 203.241.249.185 의 주소를 가지는 서버는 선정된 시험항목과 사용자가 정의한 시험에 대해 모두 정상적인 시험결과를 출력하였으며 www.openldap.com 주소를 가지는 서버는 관리자 권한이 필요치 않은 항목에 대해서는 정상적인 시험결과를 출력하여 구현한 시험도구가 정상적으로 동작함을 확인하였다.

• The KIPS Transactions:PartA
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• v.10A no.4
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• pp.339-346
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• 2003

This paper provides a framework for information assurance within collaborative design, based on a technique we call role-based viewing. Such role-based viewing is achieved through integration of multi-resolution geometry and security models. 3D models are geometrically partitioned, and the partitioning is used to create multi-resolution mesh hierarchies. Extracting a model suitable for access rights for individual designers within a collaborative design environment Is driven by an elaborate access control mechanism. 

• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.260-262
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• 2003

최근 인터넷 및 이동 통신이 발달하면서 많은 사용자를 동시에 서비스할 수 있는 고성능 메인 메모리 데이타베이스 관리 시스템에 대한 연구가 활발히 진행되고 있지만, 특정 응용에 한정되도록 개발됨으로써(ad-hoc designed system) 시스템의 범용성이 떨어질 뿐만 아니라, 고객 지향적 요구 사항을 적시에 반영할 수 있는 유연한 구조 및 다른 응용 분야로의 적용(customizing)이 어렵다. 특히, 정보 보안에 대한 문제를 해결하지 못하기 때문에 적용 영역의 확대에 걸림돌이 되고 있다. 본 논문은 접근제어에 초점을 두고 저장된 데이타에 대한 권한 없는 접근, 고의적인 파괴 및 변경으로부터 데이타베이스를 보호하여 고신뢰성을 추구하고, 다중 사용자들의 이질성을 해결하며 다양한 보안 정책을 유연하게 지원하는 고성능 메인 메모리 데이타베이스 관리 시스템을 위한 접근제어 미들웨어 시스템에 대한 프로토타입을 제시한다.

• Journal of Digital Convergence
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• v.19 no.4
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• pp.133-139
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• 2021

Due to the rapid progress in network technology, many research on content security technologies is also being conducted in the mobile digital content sector. In the meantime, content protection has been immersed in preventing illegal copying, certifying, and issuance/management certificates, but still have many vulnerabilities in managing or authenticating confidential information. This study aims to strengthen confidential information about content based on dual management of content download rights through mobile phone numbers or device numbers. It also protect replay-attack by building a secure mobile DRM system where digital content is safely distributed based on a three-stage user authentication process. In addition, blockchain-based content security enhancements were studied during the primary/secondary process for user authentication for the prevention of piracy and copyright protection. In addition, the client authentication process was further improved through three final stages of authorization in the use of illegal content, considering that legitimate users redistributed their content to third-party.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1519-1527
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• 2007

In order to combat the security threats that sensor networks are exposed to, a cryptography protocol is implemented at sensor nodes for point-to-point encryption between nodes. Given that nodes have limited resources, symmetric cryptography that is proven to be efficient for low power devices is implemented. Data protection is integrated into a sensor's packet by the means of symmetric encryption with the Dragon stream cipher and incorporating the newly designed Dragon-MAC Message Authentication Code. The proposed algorithm was designed to employ some of the data already computed by the underlying Dragon stream cipher for the purpose of minimizing the computational cost of the operations required by the MAC algorithm. In view that Dragon is a word based stream cipher with a fast key stream generation, it is very suitable for a constrained environment. Our protocol regarded the entity authentication and message authentication through the implementation of authenticated encryption scheme in wireless sensor nodes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.323-325
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• 2016

Computing loud arrival times were, important data Clouding and, without being limited to the device, may process the information. Recently, work environment and improved access to Cloud and Mobile, this decision has been made to take effect immediately. However, when such important decisions of the government, the security is required. In this paper, we study the network access and control in IoT, Cloud, Bigdata, Smartwork System applied to Mobile. Study the authentication, authorization, and security for each security level Level of Service to connect to the DB information. Research of this paper will be used as the basis for the information processing and decision-making system design and construction of public institutions and agencies as important information for the protection Smartwork System.

• Korean Security Journal
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• no.61
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• pp.39-57
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• 2019

The executive authority of the Ministry of Public Administration and Security on the 'management of security of the government complexes' is not sufficiently secured only with the organization law, the Government Organization Act. It is needed to establish an administrative actions law, an individual law that sets detailed contents and limitations of the executive authority to be stipulated. The current regulation, Regulation on the Management of the Government Complexes which is a Presidential Decree, is a legal decree that lacks a legal basis. The decree does not match with the current constitutional framework and raises the issue of its legality. The regulation may have the characteristics as a public property management law so far as it stipulates such matters as supply and maintenance management for the complexes, acquisition and disposition of complexes, facilities management of complexes, etc. However, the regulation includes high authority actions by an administrative organization, such as facilities security and order maintenance including restriction and control of access. This makes the regulation have the characteristics of a public property policy act as well. To supplement the legal framework for this situation, it is needed to level up some of the provisions relating to protection and security management to the level of an act as they stipulate high authority actions by an administrative organization. Other matters in the Regulation on the Management of the Government Complexes such as provisions relating to supply and allocation of complexes, etc. may be maintained as they are. In addition, the protection officers (general service official) does not own legal authority and have limitations on securing the capability to deal with the situations on implementing the on-site protection duty. Therefore, it is needed for the protection officers to secure protection duty-related authority by stipulating in a law. The main contents of the law on the protection and security of the government complexes may be those matters providing reservations on the implementations of laws. These may include the limitation of rights of and charging obligations on the people such as restricting the actions of personnel in the complex, rights and obligations of protection personnels relating to their duties, use of weapons, training of protection personnel, penal provisions, etc. These legal reservations should be included in an individual act.

• Journal of the Korean Geographical Society
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• v.30 no.4
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• pp.389-410
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• 1995

Large metropolitan areas in the US are distinguished by highly fragmented fiscally independent suburban municipalities and special districts. The suburban fragmentation implies the congregation of similar socio-economic groups escaped from central cities and the disparity of geographical resources among local government jurisdictions. This study examines St.Louis County suburbs as a case study for the implictions of suburban governmental fragmentation and the fiscal disparities across local governmental boundaries by analyzing their relationship with public service provision using police and public school services as examples. The distribution of fiscal resources across political boundaries, the processes which created them, and public service inequalities reproduced from the disparity of fiscal resources reveal the causes and consequences of suburban governmental fragmentation. The central part of suburban fragmentation is the segregation of public goods consumption reproduced from the disparity of local fiscal resources, and it acts as a basic geographical segregating force in the suburban spatial organization.