• 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.

• Bulletin of the Korean Mathematical Society
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• v.36 no.3
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• pp.579-588
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• 1999

In this paper we study the connections between right quasi-duo rings and 2-primal rings, including several counterexamples for answers to some questions that occur naturally in the process. Actually we concern following three questions and modified ones: (1) Are right quasi-duo rings 2-primal$\ulcorner$, (2) Are formal power series rings over weakly right duo rings also weakly right duo\ulcorner and (3) Are 2-primal rings right quasi-duo\ulcorner Moreover we consider some conditions under which the answers of them may be affirmative, obtaining several results which are related to the questions.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.4
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• pp.265-269
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• 2009

Formal specification plays important roles in guaranteeing software safety of safety-critical systems such as nuclear power plant's digital control systems. We had developed a technique [1] which synthesizes Function Block Diagram(FBD) programs from NuSCR formal requirements specifications, but it did not be used widely as it had no automatic tool support. FBD is one of the programming languages for Programmable Logic Controllers(PLC) based system. This paper introduces a CASE tool, NuSCRtoFBD, developed to automate the synthesis procedure. The CASE tool NuSCRtoFBD can reduce a number of errors occurred in the process of manual FBD programming.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.99.2-99
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• 2001

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.5
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• pp.830-843
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• 2016

The world wide increase of obesity and demands for various plus-size fashion are expanding the global plus-size fashion market. This study is to understand the market status of the US (the biggest plus-size fashion market) as well as analyze women's fashion shown in power blogs on the plus-size fashion trend. For research methods, photos from the top 10 globally ranked plus-size power blogs on Alexa.com were collected and divided into 5 plus-size body types based on: design factors, style, color, item, and texture. Pants with tops or completed outfits including pants, tops, and outer were the most common for casual styles; in addition, a tendency to pursue comfortable and naturally fitted clothes was also indicated. As for colors, the most common were blue colors and white or pastel toned colors; in addition, soft, hard, and transparent were all evenly used for materials. One-piece items were the most popular formal style that were mostly a one-tone color made with hard materials indicated by the pursuit of the fanciness and formality of a dress for a formal occasion. Black was the most common color, and the color variation was less diverse compared to that of casual styles. The most common for semi-formal styles were outfits with movability and more fanciness such as wearing a casual outer on top of a formal one-piece. When examining the fashion in plus-size blogs, there are differences in the frequency of design factors due to the diversity of body-types; in addition, different items were shown to be preferred in accordance with styles. The results of this study will help fashion companies who want to enter the global plus-size women's fashion market (including the US market); in addition, research on plus-size fashion that is changing the fashion and aesthetic paradigm is expected to contribute to academia.

• Communications of the Korean Mathematical Society
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• v.23 no.3
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• pp.307-312
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• 2008

In this note we first give a simple, direct proof of a combinatorial determinant involving the usual higher derivatives and then obtain a corresponding result in positive characteristic.

• Bulletin of the Korean Mathematical Society
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• v.50 no.5
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• pp.1623-1630
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• 2013

The aim of this paper is to prove that every quadratic formal power series ${\omega}$ can be expressed as a periodic non-simple continued fraction having period length one.

• Journal of Computing Science and Engineering
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• v.6 no.4
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• pp.310-319
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• 2012

Next generation wireless receivers demand low computational complexity algorithms with high computing power in order to perform fast signal detections and error estimations. Several signal detection and estimation algorithms have been proposed for next generation wireless receivers which are primarily designed to provide reasonable performance in terms of signal to noise ratio (SNR) and bit error rate (BER). However, none of them have been chosen for direct implementation as they offer high computational complexity with relatively lower computing power. This paper presents a low-complexity power-efficient algorithm that improves the computing power and provides relatively faster signal detection for next generation wireless multiuser receivers. Measurement results of the proposed algorithm are provided and the overall system performance is indicated by BER and the computational complexity. Finally, in order to verify the low-complexity of the proposed algorithm we also present a formal mathematical proof.

• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.157-171
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• 1999

In this work, an automatic software verification method for Nuclear Power Plant (NPP) protection system is developed. This method utilizes Colored Petri Net (CPN) for system modeling and Prototype Verification System (PVS) for mathematical verification. In order to help flow-through from modeling by CPN to mathematical proof by PVS, an information extractor from CPN models has been developed in this work. In order to convert the extracted information to the PVS specification language, a translator also has been developed. ML that is a higher-order functional language programs the information extractor and translator. This combined method has been applied to a protection system function of Wolsong NPP SDS2(Steam Generator Low Level Trip). As a result of this application, we could prove completeness and consistency of the requirement logically. Through this work, in short, an axiom or lemma based-analysis method for CPN models is newly suggested in order to complement CPN analysis methods and a guideline for the use of formal methods is proposed in order to apply them to NPP Software Verification and Validation.

• Journal of English Language & Literature
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• v.64 no.3
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• pp.329-345
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• 2018

Sun Yung Shin's poetry collection Skirt Full of Black (2007) brings the author's personal history as a Korean female adoptee to bear upon poetic language in daring formal experiments, instantiating the liminal state of being shuttled across borders to land in an in-between state of marginalization. Other Korean American poets have also drawn on the experience of transnational adoption and racialization explore the literary potential of English to materialize haunting memories or the untranslatable yet persistent echoes of a lost home that gestures across linguistic boundaries, as seen in the case of Lee Herrick or Jennifer Kwon Dobbs. Shin however dismantles the referential foundation of English as a language she was transplanted into through formal transgressions such as frazzled syntax, atypical typography, decontextualized punctuation marks, and phonetic and visual play. The power to signify and thereby differentiate one entity or meaning from another dissipates in the cacophonic feast of signs in Skirt Full of Black; the word fragments of identificatory markers that turn racialized, gendered, and culturally contained subjects into exotic things lose the power to define them as such, and instead become alterities by departing from the conventional meaning-making dynamics of language. Expanding on the avant-garde legacy of Korean American poets Theresa Hak Kyung Cha and Myung Mi Kim to delve further into the liminal space between Korean and American, referential and representational, or spoken and written words, Shin carves out a space for discreteness that does not subscribe to the hierarchical ontology of differential value assignment.