• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.46-61
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• 2002

Among the many phases involved in software development, requirements analysis phase in generally considered to play a crucial role in determining the overall software quality. Therefore, many software development companies manages the phase as one of the important phase. Especially, safety assurance through requirements analysis for safety-critical systems is quite demanding, and national and international bodies routinely require safety demonstration. Among various approaches, inspection and formal methods are generally shown to be effective. In this paper, we propose a formal verification procedure for SCR(Software Cost Reduction)-style SRS(Software Requirements Specification) using the PVS specification and verification procedure and applied this procedure to an industrial system such that a shutdown system for Wolsung nuclear power plant. This system had been verified through inspection not formal verification. The application of formal methods is rare in Korea, so it is very important to experiment about formal verification to industrial systems.

• The Journal of Korean Association of Computer Education
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• v.7 no.6
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• pp.129-139
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• 2004

In developing highly reliable systems such as C4I systems formal methods provide both developers and clients with assurance that they are in the right development processes. This paper investigates into techniques for formal specifications and tests for software components where rigorous verification is required. In particular, the paper suggests decomposition techniques for state-model based specifications using the weakest precondition, and suggests test methods for the specification by generating black box test-cases.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.519-522
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• 2001

바람직한 비즈니스 룰의 기본은 어디에 어떠한 형태로 구현되더라도 유일하고, 일관적인 모델 이여야 한다는 것이다. 또한 비즈니스 룰 자체의 정립은 의사결정 시스템을 사용함으로써 경영 전략이 바뀌어도 시스템 담당자에게 의뢰할 필요 없이 기획자가 바로 코드 값만 변경시키면 기존의 시스템을 그대로 사용할 수 있을 정도의 유연성을 가지게 된 현실에 비추어 볼 때 매우 요원한 일이다. 즉, 비즈니스 룰은 DRM(Digital Rights Management) 시스템뿐만 아니라 e-CRM을 실현하는 모든 시스템에서 사용되며, 이 비즈니스 룰의 충돌로 인해서 시스템의 작동 여부가 결정될 수 있다. 룰 자체가 자연어로 기술되고 언젠가는 모순을 유발할 가능성이 높기 때문에 먼저 명확한 논리식으로 표현하고 LEGO라는 정형기법 도구를 통해 검증하도록 한다.

• Journal of KIISE:Software and Applications
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• v.35 no.12
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• pp.731-740
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• 2008

A railway control system is one of the typical safety-critical systems. It is required to use formal methods for the requirements specification and verification in order to develop the global-standard railway control systems based on the computer systems. In this paper, we develop a guideline for requirements specification using formal methods, and present a case study of the development of a computer-based railway control system through the application of the proposed guideline. We use the Statechart and the Z method for the formal requirements specifications and verify the consistency and completeness of the formal specifications of the requirements.

• Journal of KIISE:Software and Applications
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• v.27 no.2
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• pp.120-133
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• 2000

Major obstruction of using formal methods for hybrid real-time systems in industry is the difficulty that engineers have in understanding and applying the quantitative methods in an abstract requirements phase. While formal methods technology in safety-critical systems can help increase confidence of software, difficulty and complexity in using them can cause another hazard. In order to overcome this obstruction, we propose a framework for qualitative requirements engineering of the hybrid real-time systems. It consists of a qualitative method for requirements specification, called QFM (Qualitative Formal Method), and a safety analysis method for the requirements based on a causality information, called CRSA (Causal Requirements Safety Analysis). QFM emphasizes the idea of a causal and qualitative reasoning in formal methods to reduce the cognitive burden of designers when specifying and validating the software requirements of hybrid safety systems. CRSA can evaluate the logical contribution of the software elements to the physical hazard of systems by utilizing the causality information that is kept during specification by QFM. Using the Shutdown System 2 of Wolsong nuclear power plants as a realistic example, we demonstrate the effectiveness of our approach.

• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.52-58
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• 2007

The game software development involves planning, programming and graphics. Between planning and programming, software analysis and design is essential and plays the role of a bridge. This article analyzes, for game software, the applicability of formal methods, which are widely used in general software engineering fields. Since the effective communication between game planners and game developers is crucial, appropriate application of formal methods give us a lot of benefits in view of development cost and software quality.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6372-6378
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• 2014

This study examined the formal types and public space of Mies van der Rohe's office designs in Germany. The characteristics of the formal types, the relationship between public space and formal types, and the composition of public space were analyzed by hierarchy with perspective drawings and plans. The conclusions were as follows. Mies used the formal types, such as U shape and I shape in his early days. Later, he adopted the curved shape and tried to fragment the forms by combining the curved shape with an I shape. Mies designed the entry space in front of the simple formal types. The curved shape was used to create various hierarchical courtyards and rear gardens. The results suggest that Mies developed his own ideas on the formal types and public space utilizing a variety of methods.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.151-159
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• 2024

Twin clutch model enables the power-shifts as conventional planetary automatic transmission and eradicates the disadvantages of single clutch trans- mission. The automatic control of the dual clutches is a problem. Particularly to control the clutching component that engages when running in one direction of revolution and disengages when running the other direction, which exchange the torque smoothly during torque phase of the gearshifts on planetary-type automatic transmissions, seemed for quite a while hard to compensate through clutch control. Another problem is to skip gears during multiple gearshifts. However, the twin clutch gear control described in ["M Goetz, M C Levesley and D A Crolla. Dynamics and control of gearshifts on twin clutch transmissions, Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 2005"], a significant improvement in twin clutch gear control system is discussed. In this research our objective is to formally specify the twin clutch gear control system and verify it with the help of formal methods. Formal methods have a high potential to give correctness estimating techniques. We use UPPAAL for formal specification and verification. Our results show that the twin clutch gear control model partially fulfills its functional requirements.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.934-936
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• 2005

실시간 시스템에서 스케줄링 가능성 여부는 매우 중요하다. 그래서 실시간 시스템이 주어진 시간적 제약 사항을 만족 시킬 수 있도록 스케줄러 등 많은 연구들이 진행되고 있다. 그런데 기존의 스케줄링 방식은 외부 환경이나, 태스크에 대한 정확한 정보를 요구한다. 하지만 이런 정보를 정확히 예측하는 것이 매우 힘들다. 그래서 이런 정보들에 따라 시스템의 성능이 저하 되거나, 아니면 오류를 야기 할 수 있다. 그래서 본 논문에서는 실시간 시스템의 이론에 제어 이론을 접목하여 시스템에 외부 환경에 대해 강인 하면서 높은 효율을 보일 수 있는 스케줄러를 설계하고 제시 한다.

• The KIPS Transactions:PartD
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• v.8D no.1
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• pp.62-70
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• 2001

Correct descriptions for software component functions become a strong requirement in developing critical software especially on the area of real-time applications. In this paper, we introduce both formalization of software design using patterns and verification methods in order for the components to increase their understandability. In particular, the paper investigates into a means of formal description techniques based on VDM++ for the software components, and provides adequacy proof steps for a given functional descriptions.