• ETRI Journal
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• v.25 no.3
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• pp.187-194
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• 2003

Delay testing has become an area of focus in the field of digital circuits as the speed and density of circuits have greatly improved. This paper proposes a new scan flip-flop and test algorithm to overcome some of the problems in delay testing. In the proposed test algorithm, the second test pattern is generated by scan justification, and the first test pattern is processed by functional justification. In the conventional functional justification, it is hard to generate the proper second test pattern because it uses a combinational circuit for the pattern. The proposed scan justification has the advantage of easily generating the second test pattern by direct justification from the scan. To implement our scheme, we devised a new scan in which the slave latch is bypassed by an additional latch to allow the slave to hold its state while a new pattern is scanned in. Experimental results on ISCAS'89 benchmark circuits show that the number of testable paths can be increased by about 45 % over the conventional functional justification.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.1
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• pp.1-9
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• 1990

This paper investigates the significance and the implication of the pointer scheme, which was recently adapted by CCITT as a standard synchronization method in the broadband network-node interface environment, and discusses the merits of the pointer scheme in comparison with the conventional positive justification method. It also analyzes the jitter performance of the communication system employing the pointer scheme based on the fact that the pointer scheme corresponds to a multiple-bit positive/zero/negative justification.

• Research in Mathematical Education
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• v.8 no.1
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• pp.1-18
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• 2004

Current interest in mathematics learning that focuses on understanding, mathematical reasoning and meaning making underscores the need to develop ways of analyzing classrooms that foster these types of learning. In this paper, the author show that the constructs of social and socio-mathematical norms, which grew out of taking a symbolic interactionist perspective, and Toulmins scheme for argumentation, as elaborated for mathematics education by Krummheuer [The ethnology of argumentation. In: The emergence of mathematical meaning: Interaction in classroom cultures (1995, pp. 229-269). Hillsdale, NJ: Erlbaum], provide us with means to analyze aspects of explanation, justification and argumentation in mathematics classrooms, including means through which they can be fostered. Examples from a variety of classrooms are used to clarify how these notions can inform instruction at all levels, from the elementary grades through university-level mathematics.

• Communications of Mathematical Education
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• v.18 no.1 s.18
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• pp.1-18
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• 2004

Current interest in mathematics learning that focuses on understanding, mathematical reasoning and meaning making underscores the need to develop ways of analyzing classrooms that foster these types of learning. In this paper, I show that the constructs of social and sociomathematical norms, which grew out of taking a symbolic interactionist perspective, and Toulmins scheme for argumentation as elaborated for mathematics education by Krummheuer, provide us with means to analyze aspects of explanation justification and argumentation in mathematics classrooms, including means through which they can be fostered. Examples from a variety of classrooms are used to clarify how these notions can inform instruction at all levels, from the elementary grades through university-level mathematics.

• The Mathematical Education
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• v.43 no.1
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• pp.97-107
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• 2004

Current interest in mathematics learning that focuses on understanding, mathematical reasoning and meaning making underscores the need to develop ways of analyzing classrooms that foster these types of learning. In this paper, I show that the constructs of social and sociomathematical norms, which grew out of taking a symbolic interactionist perspective, and Toulmin's scheme for argumentation, as elaborated for mathematics education by Kummheuer, provide us with means to analyze aspects of explanation, justification and argumentation in mathematics classrooms, including means through which they can be fostered. Examples from a variety of classrooms are used to clarify how these notions can inform instruction at all levels, from the elementary grades through university-level mathematics.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.181-187
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• 2011

Korean government has introduced the modal shift grant scheme in July 2010 to help the competitiveness of carriage of rail freight and awarded a grant to private companies shifting mode of transportation from road to rail in the carriage of freight: the additional costs incurred in the modal shift are supported by the government. However, there arise needs for the amendment of the modal shift grant scheme. This study reviewed the modal shift grant schemes of foreign countries, such as EU, UK and Japan, and drew implications. Furthermore, this study suggested the future directions of the modal shift grant scheme from the respects of the maximization of the effects of the grant scheme, continual rail use of existing rail freight, and justification of the grant scheme. Finally, policy measures amending the existing modal shift grant scheme were suggested.

• Journal of The Korean Association For Science Education
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• v.38 no.2
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• pp.249-257
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• 2018

The purpose of this study was to analyze the knowledge and ability levels of middle school students in four areas: conceptual understanding, argument construction, justification schemes, and use of scientific knowledge in a causal explanation for a genetic phenomenon. A group of 162 middle school students who have taken a class titled Genetics and Evolution participated in the study. Each student answered-and justified the answer to-one question pertaining to genetics. Ability levels were rated from level 0 to level 4, with 4 being the top rating. Students were required to choose one of two competing arguments to explain whether green seed pimps and red seed pimps of the same size and shape were the same species or not. Analyzing conceptual understanding: 47% of the respondents provided the correct answer. Analyzing their abilities for constructing an argument: 75% of the students with the correct answer and 42% of the students with the incorrect answer were evaluated to be at ability level 3 or 4 for argument construction. Analyzing the students' justification schemes: "Scientific idea" and "Analogy" were the most frequently used schemes. Analyzing their use of scientific knowledge: of the students who selected the scientific idea justification scheme, 36% used the correct scientific knowledge, but the remainder used inaccurate or nonspecific scientific knowledge. These findings provide implication for encouraging argumentative writing explaining scientific phenomena regarding epistemic practice.

• The Mathematical Education
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• v.41 no.3
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• pp.291-318
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• 2002

We investigated on the primary school children's abilities of formal reasoning. Seventy students in grade 5 participated in the study. They responsed their best reactions on the problems constituted of three parts requiring the informal or formal reasoning and generalization. Their reactions are classified by some criteria depending the level of reasoning. About 10 students showed that they constructed a kind of scheme for solving the problems, similar to formal reasoning and beyond naive informal reasoning. And about 30 students did so partially. We concluded that the teaching and learning of reasoning by the progressive increasing the degree of rigor from grade 5 is possible.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.771-774
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• 1999

This paper presents a new timing structure for real time communications and its performance analysis. The cycle time consists of several "one time slot" which may be an interval defined by a synchronous traffic part followed by an asynchronous traffic part. If a station receives a token within a synchronous interval, it transmits its synchronous message if any, otherwise it may transmit an asynchronous message. This scheme is different from usual allocation schemes which divide one cycle into alternating synchronous and asynchronous subslots. This protocol is designed to prevent low priority messages from delaying too much due to lots of high priority messages. We propose the algorithm and show its justification by simulation.

• Journal of the Korean Society of Safety
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• v.22 no.3 s.81
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• pp.88-97
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• 2007

A point based speed enforcement system(SES) has been widely used in roadways to reduce the operating speeds and potential traffic accidents. Recently, the needs for introudcing new SES using point-to-point speed measurement was presented, however, no practical guidelines or justification of the system was available. This study investigated the effectiveness of the current SES and introduction of the new SES through user interview survey method. Survey results showed that 33% of respondents were unsatisfactory to the current way of SES operation, which was 11% higher than satisfactory respondents, and about 70% of the respondents supported the introduction of point-to-point based SES operation. A majority of respondents preferred the straight roadway segment, bridge and tunnel, and curved roadway segment for a start application site with the segment length of 1-5 km long. Using these survey results, an introduction scheme was discussed in terms of legal bases, installation criteria, and operational guidelines.