• School Mathematics
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• v.18 no.4
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• pp.749-771
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• 2016

The purpose of this study is to analyze mathematical tasks of Korea and the USA textbooks focused on conditions for parallelograms. In this study, structures of task, types of proof and reasoning, and levels of cognitive demand are investigated. The conclusion is as follows: First, with respect to structures of task, structures presented in the USA textbooks are more diverse. Second, with respect to types of proof and reasoning, Korea and the USA prefer IC task and DA task. And task types presented in the USA textbooks are more diverse. Third, with respect to levels of cognitive demand, in both Korea and the USA textbooks, PNC task and PWC task account most. And compared to the USA, Korea prefer algorithms. In addition, we find out implications for reconstruction of Korea textbook. It is as follows: First, with respect to structures of task and types of proof and reasoning, the diversity of composition needs to be raised. Second, with respect to levels of cognitive demand, the concentration in PNC task needs to be declined. And levels of cognitive demand on types of tasks need to be reconsidered. Third, with respect to tasks' topic and material, internal and external connectivities of mathematics need to be strengthened.

• The Mathematical Education
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• v.58 no.2
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• pp.161-185
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• 2019

This study aims to examine pre- and in-service mathematics teachers' reasoning and how they justify their reasoning. For this purpose, we developed a set of mathematical tasks that are based on mathematical contents for middle grade students and conducted the survey to pre- and in-service teachers in Korea. Twenty-five pre-service teachers and 8 in-service teachers participated in the survey. The findings from the data analysis suggested as follows: a) the pre- and in-service mathematics teachers seemed to be very dependent of the manipulation of algebraic expressions so that they attempt to justify only by means of procedures such as known algorithms, rules, facts, etc., rather than trying to find out a mathematical structure in the first instance, b) the proof that teachers produced did not satisfy the generality when they attempted to justify using by other ways than the algebraic manipulation, c) the teachers appeared to rely on using formulas for finding patters and justifying their reasoning, d) a considerable number of the teachers seemed to stay at level 2 in terms of the proof production level, and e) more than 3/4 of the participating teachers appeared to have difficulty in mathematical reasoning and proof production particularly when faced completely new mathematical tasks.

• Korean Journal of Logic
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• v.14 no.2
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• pp.39-76
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• 2011

We explain some basic elements of Martin-L$\ddot{o}$f's type theory and examine the distinction between propositions and judgments. In section 1, we introduce the problem. In section 2, we explain the concept of proposition in the intuitionistic type theory as a development of the intuitionistic conception of proposition. In section 3, we explain the concept of judgment in the intuitionistic type theory. In section 4, we explain some basic inference rules and examine a particular derivation in the theory. In section 5, we examine one route from the Fregean distinction between propositions and judgments to the distinction between them in the intuitionistic type theory, paying attention to the alleged necessity for introducing different forms of judgments.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.12
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• pp.485-496
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• 2018

So far, the deep learning, a field of artificial intelligence, has achieved remarkable results in solving problems from unstructured data. However, it is difficult to comprehensively judge situations like humans, and did not reach the level of intelligence that deduced their relations and predicted the next situation. Recently, deep neural networks show that artificial intelligence can possess powerful relational reasoning that is core intellectual ability of human being. In this paper, to analyze and observe the performance of Relation Networks (RN) among the neural networks for relational reasoning, two types of RN-based deep neural network models were constructed and compared with the baseline model. One is a visual question answering RN model using Sort-of-CLEVR and the other is a text-based question answering RN model using bAbI task. In order to maximize the performance of the RN-based model, various performance improvement experiments such as hyper parameters tuning have been proposed and performed. The effectiveness of the proposed performance improvement methods has been verified by applying to the visual QA RN model and the text-based QA RN model, and the new domain model using the dialogue-based LL dataset. As a result of the various experiments, it is found that the initial learning rate is a key factor in determining the performance of the model in both types of RN models. We have observed that the optimal initial learning rate setting found by the proposed random search method can improve the performance of the model up to 99.8%.

• Journal of KIISE:Software and Applications
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• v.27 no.4
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• pp.412-421
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• 2000

In spite that the main contents of mathematical and scientific learning are understanding principles and their applications, most of existing educational softwares are based on rote learning, thus resulting in limited educational effects. In the artificial intelligence research, some progress has been made in developing automatic tutors based on proving and simulation, by adapting the techniques of knowledge representation, search and inference to the design of tutors. However, these tutors still fall short of being practical and the turor, even a prototype model, for learning problem solving is yet to come out. The geometry problem-solving tutor proposed by this research involves dynamic inference performed in parallel with learning. As an ontology for composing the problem space within a real-time setting, we have employed the notions of propositions, hypotheses and operators. Then we investigated the mechanism of interactive learning of problem solving in which the main target of inference involves the generation and the test of these components. Major accomplishment from this research is a practical model of a problem tutor embedded with a series of inference techniques for algebraic manipulation, which is indispensable in geometry problem solving but overlooked by previous research. The proposed model is expected to be applicable to the design of problem tutors in other scientific areas such as physics and electric circuitry.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.265-274
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• 1993

정보화 사회에서 대량으로 생산된 데이타 코드들은 일관된 설계 원칙없이 필요할 때마다 만들어 사용함으로써 정보의 중복 저장 및 정보교환에 있어서의 변환 작업등으로 인한 경비의 소요가 상당한 실정이다. 이러한 문제점에 대한 해결책으로 본 논문에서는 데이타코드 설계자가 일관성있게 데이타코드를 생성할 수 있도록 도와주는 데이타 코드 생성 지원 전문가 시스템의 설계에 관하여 연구하였다. 불완전 영역 설계를 위한 지식 획득과 표현에 적합한 전문가 시스템 쉘인 GUESS(Guideline Underlying Expert system Shell)를 설계하였다. GUESS는 전문가 시스템을 설계 지원 도구로 사용하는 사용자에게 기존에 작성된 적절한 설계 용례를 선택의 기준으로 제공하며, 유연성 있는 작업 지침들을 규칙으로 포함하고 있다. GUESS는 Prolog언어를 기반으로 한 추론기관과 설계지침을 포함하는 정적지식, 외부 데이타베이스를 연결한 동적 정보, 설계 세부방법을 담고 있는 부가도구들로 구성된다. GUESS/DCG는 데이타 코드 생성을 지원하기 위하여 데이타 코드의 유형과 선택기준 및 설계원리를 정적지식으로 가지며, 이를 경험적으로 탐색하는 추론 기관 및 사용자인 데이타 코드 설계자와 적절한 대화식 접근을 가능하게 하는 설명부분과 대화 인터페이스를 GUESS를 바탕으로 구현한 것이다. 특히 동적 정보의 적절한 이용과 데이타 코드의 통합된 저장, 일관성 있는 운영을 보장하기 위하여 개발중인 데이타 코드 관리시스템과의 인터페이스 부분을 추가하여 기존에 운영되고 있는 데이타 코드의 참고와 호환성, 확장성을 유지하였다. 이 시스템은 데이타 코드 관리시스템에 일관된 생성 수단을 제공하는것 외에도, 각 기관에서 대량으로 작성되는 데이타 코드를 유지, 보수하는 작업에도 큰 기여를 할 것이다.지의 선택작업이 행해지는 경우에 촛점을 맞추었다. 그리하여 다작업장의 휴리스틱에 의거한 작업순서 결정을 위해 우선 BB의 상한을 구하는 연구를 행했다. 이를 위해 우선 단일작업장에서 야기될 수 있는 모든 상황을 고려한 최적 작업순서 결정규칙을 연구했으며, 이의 증명을 위해 이 규칙에 의거했을 때의 보완작업량이 최소가 된다는 것을 밝혔다. 보완작업 계산의 효율성을 제고하기 위해 과부하(violation)개념을 도입하였으며, 작업유형이 증가된 상황에서도 과부하 개념이 보완작업량을 충분히 반영할 수 있음을 밝혔다. 본 연구에서 제시한 최적 작업순서 규칙에 의거했을 때 야기될 수 있는 여러가지 경우의 과부하를 모두 계산했다. 앞에서 개발된 단일작업량의 최적 작업순서 결정규칙을 이용하여 다작업장의 문제를 실험했다. 이 문제는 규모가 매우 크므로 Branch & Bound를 이용하였으며, 각 가지에서 과부하량이 최적인 경우만을 고려하는 휴리스틱을 택하여 실험자료를 이용하여 여러 회 반복실험을 행했다. 그리고 본 연구의 성과를 측정하기 위해 휴리스틱 기법시 소요되는 평균 CPU time 범위에서, 랜덤 작업순서에 따른 작업할당을 반복실험하여 이중 가장 좋은 해와 비교했다. 그러나 앞으로 다작업장 문제를 다룰 때, 각 작업장 작업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용을 발생시키는 작업장의 작업순서결정에 대해서도 연구를 행하여, 보완작업비용과 준비비용을 고려한 GMMAL 작업순서문제를 해결하기 위한 연구가 수행되어야 할 것이다.로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.429-440
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• 2001

To achieve a computer tutor framework with high learning effects as well as practicality, the goal of this research has been set to developing an intelligent tutor for problem-solving in mathematics domain. The maine feature of the CyberTutor, a computer tutor developed in this research, is the facilitation of a learning environment interacting in accordance with the learners differing inferential capabilities and needs. The pedagogical information, the driving force of such an interactive learning, comprises of tutoring strategies used commonly in various domains such as phvsics and mathematics, in which the main contents of learning is the comprehension and the application of principles. These tutoring strategies are those of testing learners hypotheses test, providing hints, and generating explanations. We illustrate the feasibility and the behavior of our propose framework with a sample problem-solving learning in geometry. The proposed tutorial framework is an advancement from previous works in several aspects. Firstly, it is more practical since it supports handing of a wide range of problem types, including not only proof types but also finding-unkown tpes. Secondly, it is aimed at facilitating a personal tutor environment by adapting to learners of varying capabilities. Finally, learning effects are maximized by its tutorial dialogues which are derived from real-time problem-solving inference instead of from built-in procedures.

• Economic and Environmental Geology
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• v.52 no.5
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• pp.459-469
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• 2019

We present a quantitative evaluation of density, vesicularity and microtextures for coarse lapilli collected from the Jugam Scoria Deposits, northeastern Ulleung Island. Lapilli from the deposits have modal vesicularities of 61% in the lower part and 67% in the upper part, and vesicle populations dominated by non-interconnected subround vesicles. Clasts of modal vesicularity have margin-parallel zonation, with subaerially quenched rims interpreted to preserve "syn-fragmentation" magmatic textures in microlite-free sideromelane rims, grading "post-fragmentation" tachylitic interiors with vesicle and microlite textures that progressively coarsen from rim to interior. Degassing scenarios are linked to syn-fragmentation vesicle textures to demonstrate that the magmas degassed in dominantly closed systems. And diffusion-controlled cooling rates of trachyandesitic pyroclasts in contact with atmosphere are linked to post-fragmentation evolution of vesicle and microlite textures to infer about transportation and dispersal of the pyroclasts in low shooting jets. These textural analyses show that the Jugam eruptions were strictly applied to the strombolian type, analogous to the hawaiian type among any classical subaerial eruption type.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.169-178
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• 2008

Level of Service (LOS) is one of ways to evaluate operational conditions. It is very important factor in evaluation especially for the facility of highways. However, some studies proved that ${\upsilon}/c$ ratio and accident rate is appeared like a second function which has a U-form. It means there is a gap between LOS and safety of highway facilities. Therefore, this study presents a method for evaluation of a signalized intersection which is considered both smooth traffic operation (delay) and traffic safety (accident). Firstly, as a result of our research, accident rates and EPDO are decreased when it has a big delay. In that reason, it is necessary to make a new Level of Service included traffic safety. Secondly, this study has developed a negative binominal regression model which is based on the relation between accident patterns and stream. Thirdly, standards of LOS are presented which is originated from calculation between annual delay costs and annual accident cost at each intersection. Lastly, worksheet form is presented as an expression to an estimation step of a signalized intersection with traffic accident prediction model and new LOS.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.540-559
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• 2007

The purpose of this paper is to analyse the locations and to interpret the landscapes of the local towns in Joseon Dynasty from Feng-shui's point of view. As a result of analysing the locations of towns in Gyeongsang Province, the towns which have typical Feng-shui landscapes make up to 58% of the total. Historically, the local towns that were established in the early period of the Joseon Dynasty didn't reveal Feng-shui's landscape, but those that were established in the late period of the Joseon Dynasty revealed the Feng-shui's landscape clearly. In this article, I classify the local towns of the Gyeongsang Province into 3 types: 1. Non Feng-shui type These towns are located near the seashore. The main reason that these towns were located at the seashore was defense against an enemy. 2. Semi Feng-shui type. These towns don't have natural location but have a man-made landscape, based on the principles of Feng-shui. 3. Typical Feng-shui type. These towns were typically administrational towns which were located at the center of a local region.