• Journal of the Korean Society of Systems Engineering
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• v.6 no.2
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• pp.37-45
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• 2010

Requirements engineering is an important phase in a system's life cycle. It is important to perform it correctly. The increasing complexity of systems makes requirements engineering activities more difficult. Non-functional requirements are drivers to emerge how much emergent system properties to aim for success. All functional requirements may be satifsfied, but if the level of desired non-functional requirements are overlooked, the system development will fail. There is growing awareness of the importance of defining non-functional requirements early in the process among the requirements engineering (RE) community. This paper propses a SysML based approach for non-functional requirements to identify and specify very early in the process or requirements engineering.

• Journal of the Korea Society of Computer and Information
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• v.24 no.3
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• pp.65-75
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• 2019

Non-Functional Requirements (NFR) play a crucial role during the software development process. Currently, NFRs are considered more important than Functional Requirements and can determine the success of a software system. NFRs can be very complicated to understand due to their subjective manner and especially their conflicting nature. Self-adaptive systems (SAS) are operating in dynamically changing environment. Furthermore, the configuration of the SAS systems is dynamically changing according to the current systems context. This means that the configuration that manages the trade-off between NFRs in this context may not be suitable in another. This is because the NFRs satisfaction is based on a per-context basis. Therefore, one context configuration to satisfy one NFR may produce a conflict with another NFR. Furthermore, current approaches managing Non-Functional Requirements trade-off stops managing them during the system runtime which of concern. To solve this, we propose fragmentizing the NFRs and their alternative solutions in form of Multi-entity Bayesian network fragments. Consequently, when changes occur, our system creates a situation specific Bayesian network to measure the impact of the system's conditions and environmental changes on the NFRs satisfaction. Moreover, it dynamically decides which alternative solution is suitable for the current situation.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.98-107
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• 2019

The defense system development process is a process of developing various systems that perform functions in various functional areas such as battlefield awareness, command control, force application, and logistical support. In other words, the defense system development process is a process of developing many systems simultaneously in various functional areas. Various systems developed through this process should be interoperable so that they can be integrated and operated in a joint warfighting environment. To successfully implement this, the US Department of Defense uses the Joint Capability Integrated Development System(JCIDS) for the defense system development, and within this JCIDS processes the Capability Based Assessment(CBA) methodology as its core technology. This CBA methodology transforms the mission activity requirements to functional capability requirements logically and transforms the functional capability requirements to system requirements logically also. Smart City is a city that improves the convenience and quality of life of the citizen by integrates various systems that perform various functions of the city and smarties various functional systems with smart services by using IT technology. In other words, defense system development and smart city development have a common feature of the process of developing many systems simultaneously in various functional areas. In order to address the problem of having to develop many systems simultaneously in each functional area, it is important to logically transform the various mission scenarios into functions and logically transform the functions into systems. Therefore, a joint capability integrated development system and its core methodology, Capability Based Assessment(CBA), can be applied to smart city development. This paper proposes a method for performing a smart city concept design method using the capability based evaluation (CBA) method.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.28 no.2
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• pp.35-56
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• 2017

The government-affiliated organizations are required the autonomous record preservation and management, considering their management independence and specialty. In absence of general record management system for government-affiliated organizations, establishment of the standard; Functional requirements of systems with record management for government-affiliated organizations, etc. NAK/S 24:2014(v1.0) is meaningful because it can consensus the functional requirements and directions which are considered when organizations develop in-house record management systems. This study aims to analyze functional requirements and suggest procedures and strategies for application of the standard in the case of development of the record management system.

• The Journal of Korean Association of Computer Education
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• v.9 no.4
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• pp.43-54
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• 2006

In general, user requirements in web-based learning systems are divided into functional and non-functional requirements. Developers are responsible for the verification of quality related requirements, which is known to be difficult to perform. This paper suggests a verification method that can be applied in the area where the conformance of implementation for non-functional requirements is required. The paper performs tests for non-functional requirements by using the information extracted from quality related features that have imposed constraints on design activities.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.52-60
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• 1999

By implementing the Systems Engineering process for the aircraft preliminary design, functional analysis study is performed, hence Functional Interface Data Flow(FIDF) and Functional Flow Block Diagram(FFBD) are generated. Based on FIDF and FFBD, allocable and non-allocable design/performance/RM＆S requirements are allocated to the appropriate levels. Weight and cost tracking and design margin management methodologies are studied and implemented for the balanced aircraft design.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1591-1598
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• 2011

The objective of this paper is to study how to apply the functional models in the design reviews and the validation of the subsequent design specifications and standards in the urban rail transit standardization program. The functional models can be obtained based on the requirements. Specifically, the requirements are first represented by the use case and sequence diagrams and then the results are transformed into the functional models using the Systems Modeling Language (SysML) diagrams and the FFBD (Functional Flow Block Diagram) and others. Based on the results of the study, it can be checked whether the original requirements have been reflected properly in the designs. Also, it can be seen that how the possible changes in the requirements affect the functions and thus how the designs should be changed accordingly.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.5
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• pp.801-807
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• 2010

Requirements management is one of the most essential activities of systems engineering in developing successful weapon systems. Particularly it is very important to consistently manage the traceability among the user requirements, the system requirements, the development specifications and the testing plans throughout the entire life cycle of the weapon system. However, the most part of requirements-related activities has centered around the functional and performance requirements but the integrated logistics support(ILS) requirement has not properly been managed. In this regard, a special attention is needed to develop and manage the ILS requirements. To do so, the ANSI/EIA-632 standard can be referred as a starting point since the ILS requirements of the weapon system under development are specified by the enabling products whereas the functional and performance requirements are covered by the end product requirements. Specifically, we first review and model several cases of previous weapon systems development, which reveals the problem of interest. Then, under the framework of ANSI/EIA-632, we study a hierarchical model for effectively managing ILS requirements by analyzing the features of ILS requirements. Finally, the value of the proposed model is discussed through the case study of electronic warfare equipment.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1216-1220
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• 2007

All the systems can be used properly for the original purpose when they can make the functions required for the users be concrete. Especially in the case that many technical systems are integrated like railroad systems, physically useful systems could be built if requirements analyses applying systems engineering and the process of functional design had to be supported. This paper is intended to review and present the measures and procedures to correctly supply the systems to users by giving systems manufactures and suppliers requirements in order to supply safe systems using safety analysis techniques named FHA(Functional Hazard Analysis) and Hazop Study.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.463-478
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• 2019

The most important non-functional requirements for dependability of any Embedded Real-Time Safety Systems are safety, availability and reliability requirements. System architecture plays the primary role in achieving these requirements. Compliance with these non-functional requirements should be ensured early in the development cycle with appropriate considerations during architectural design. In this paper, we present an application of system architecture modeling for quantitative assessment of system dependability. We use probabilistic model checker (PRISM), for dependability analysis of the DTMC model derived from system architecture model. In general, the model checking techniques do not scale well for analyzing large systems, because of prohibitively large state space. It limits the use of model checking techniques in analyzing the systems of practical interest. We propose abstraction based compositional analysis methodology to circumvent this limitation. The effectiveness of the proposed methodology has been demonstrated using the case study involving the dependability analysis of safety system of a large Pressurized Water Reactor (PWR).