• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.14 no.4
• /
• pp.49-59
• /
• 2004

Boolean function synthesize problem is to find a boolean expression with in/outputs of original function. This problem can be modeled into a 0-1 integer programming. In this paper, we find a boolean expressions of S-boxes of DES for an example, whose algebraic structure has been unknown for many years. The results of this paper can be used for efficient hardware implementation of a function and cryptanalysis using algebraic structure of a block cipher.

• Journal of Elementary Mathematics Education in Korea
• /
• v.14 no.3
• /
• pp.937-957
• /
• 2010

The purpose of this study is to discover the features of symbol sense. This study tries to sum up the meaning and elements of symbol sense and the measures to improve them through documents. Also based on this, it analyzes the learning conditions about symbol sense for 6th grade mathematically able students and suggests the method that activates symbol sense in the math of elementary schools. Considering various studies on symbol sense, symbol sense means the exact knowledge and essential understanding in a comprehensive way. Symbol sense is an intuition about symbols that grasps the meaning of symbols, understands the situation of question, and realizes the usefulness of symbols in resolving a process. Considering all other scholars' opinions, this study sums up 5 elements of the symbol sense. (The recognition of needs to introduce symbol, ability to read the meaning of symbols, choice of suitable symbols according to the context, pattern guess through visualization, recognize the role of symbols in other context) This study draws the following conclusions after applying the symbol questionnaires targeting 6th grade mathematically able students : First, although they are math talents, there are some differences in terms of the symbol sense level. Second, 5 elements of the symbol sense are not completely separated. They are rather closely related in terms of mainly the symbol understanding, thereby several elements are combined.

• Journal of the Korea Computer Graphics Society
• /
• v.6 no.1
• /
• pp.37-50
• /
• 2000

Using the complex formulation of plane curves which R. T. Farouki introduced, we can identify any plane polynomial curve with only a polynomial with complex coefficients. In this paper, using the well-known fundamental theorem of algebra, we completely factorize the polynomial over the complex number field C and from the completely factorized form of the polynomial, we find a new necessary and sufficient condition for a plane polynomial curve to be a Pythagorean-hodograph curve, obseving the set of all roots of the complex polynomial corresponding to the plane polynomial curve. Applying this method to space polynomial curves in the three dimensional Minkowski space $R^{2,1}$, we also find the necessary and sufficient condition for a polynomial curve in $R^{2,1}$ to be a PH curve in a new finer form and characterize all possible curves completely.

• The Journal of the Korea Contents Association
• /
• v.13 no.3
• /
• pp.119-130
• /
• 2013

This paper researches the algorithm, whose materiality and expressiveness can be obtained through live coding. Live coding is an improvised genre of music that generates sounds while writing code in real time and projecting it onto a screen. Previous studies of live coding have focused on the development environment to support live coding performance effectively. However, this study examines the aesthetic attitude immanent in the realization of the algorithm through analyzing mostly used languages such as ChucK, Impromtu, and the visualization of live code and cases of "aa-cell" and "slub" performance. The aesthetic attitudes of live coding performance can be divided into algebraic and geometric attitudes. Algebraic attitudes underline the temporal development of concepts; geometric attitudes highlight the materialization of the spatial structure of concepts through image schemas. Such a difference echoes the tension between conception and materiality, which appears in both conceptual and concrete poetry. The linguistic question of whether conception or materiality is more greatly emphasized defines the expressiveness of the algorithm.

• Journal of KIISE:Databases
• /
• v.27 no.2
• /
• pp.185-198
• /
• 2000

Recently the technological advance in the hardware dealing with multimedia data as well as the explosive increase of the volume of multimedia data bring about new interest in the use of multimedia presentations in many application domains. To use multimedia presentations efficiently, the integration of multimedia presentations into DBMS is necessary. This paper presents a multimedia presentatation query language based on contents and query processing techniques. Presently, multimedia presentation authoring tools denote a multimedia presentation using a presentation graph which is a DAG. A Node in the graph is a same type of media stream and edges denote a play-out order and a synchronization way among nodes. The contents of presentations graphs are the information of each stream, the sequential order of the information inside each stream and the play-out order among the streams. GCalculus/S is a calculus-based query language and can deal with the contents of a presentation graph and physical characteristics of multimedia data. It expresses the sequential order of information inside each stream and the play-out order of streams of a presentation graph using temporal operators Next, Connected and Until. O-Algebra, which is object algebra, is extended to process GCalculus/S queries.

• Journal of the Korea Society for Simulation
• /
• v.19 no.3
• /
• pp.109-117
• /
• 2010

In this study, we consider stationary waiting times in a simple fork-and-join type queue which consists of three single-server machines, Machine 1, Machine 2, and Assembly Machine. We assume that the queue has a renewal arrival process and that independent service times at each node are either deterministic or non-overlapping. We also assume that the Machines 1 and 2 have an infinite buffer capacity whereas the Assembly Machine has two finite buffers, one for each machine. Services at each machine are given by FIFO service discipline and a communication blocking policy. We derive the explicit expressions for stationary waiting times at all nodes as a function of finite buffer capacities by using (max,+)-algebra. Various characteristics of stationary waiting times such as mean, higher moments, and tail probability can be computed from these expressions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.6
• /
• pp.82-88
• /
• 2001

This paper considers the problem of the identification of the time invariant parameters of distributed systems. In general, the parameters are identified by using the CBPOM(Conventional Block Pulse Operational Matrices), but in this paper, the parameters ard identified by using the EBPOMS(Extended Block Pulse Operational Matrices) which can reduce the burden of operation md the volume of error caused by matrices multiplication. The simulation cloves the effectiveness of the proposed method.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.4
• /
• pp.443-452
• /
• 1995

Object-oriented database systems have been proposed as an effective solution for providing the data management facilities of complex applications. Proving this claim and the investigation of related issues such as query processing have been hampered by the absence of a formal object-oriented query model. In this paper, we not only define a query model based on aggregation inheritance but also develop semantic rewriting rules which are applied to equivalence preserving rewrite rules in algebraic expression of a query. Analyzing semantically the query model, the query model can be optimized to logically object-oriented query processing. And algebra expresstions of a query can be optimized by applying equivalence preserving rewrite rules.

• Communications of Mathematical Education
• /
• v.10
• /
• pp.519-528
• /
• 2000

최근 10 여년 동안 교육 현장의 각 부분에 여러 가지 종류의 테크놀로지가 도입되면서, 교육의 내용과 방법에 있어서 점진적인 변화가 나타나고 있다. 예를들어, 수학 과목에 있어서는 그래픽 계산기, 도형 및 기하 학습 프로그램, 스프레드 시트, 함수 그래픽 프로그램 등의 도입으로 교과 과정 전반에 걸친 변화가 일고 있는데, 처음에는 이들 테크놀로지가 단순히 기존의 수업에서 수많은 반복을 요하거나, 지필식 방식으로는 정확하게 나타내기 어려운 도형이나 그래프를 빠르고 정확하게 그려내주는 보조수단으로 사용되었지만, 시간이 지나면서 이들 테크놀로지에 대한 활용도가 높아지게 되고, 이들 테크놀로지에 대한 교사들의 활용능력이 증대됨에 다라서, 이러한 테크놀로지가 단순한 보조수단에 머무르지 않고 주지에 기술이나 개념을 설명하는 방법 자체를 변화시키고 있다. 예를들어, 함수 교육에 있어서 그래픽 프로그램이 사용될 때에도, 초기 단계에서는 이들 함수의 개념을 설명할 때에는 거의 집합론이나 대수학적인 방법을 이용하였고, 최종 단계로 이들 함수를 좌표계 위에 표현하기 위한 보조수단으로 잠깐씩 사용되는 경우가 대부분이었으나, 최근들어서는 함수 학습의 초기과정부터 곧바로 이들 그래프 프로그램을 적극적으로 도입하여 학습자로 하여금 다양한 그래프 조작을 하게 함으로써, 어려운 집합론이나 대수학적인 개념을 도입하지 않고서도 함수에 대한 개념을 시각적으로 직관적으로 파악하도록 하는 학습 방안들이 제시되고 있는 것이다. 본 고에서는 현행 중고등학교 함수 교육 과정에서 그래프에 대한 다양한 조작 기능을 제공함으로써 학습자로 하여금, 제시되는 함수에 대한 시각적이고 직관적인 이미지를 가질 수 있도록 하기 위해서 개발된 ‘그래프 마법사’라는 프로그램을 소개하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2018.11a
• /
• pp.320-322
• /
• 2018

선박이 부두의 계류시설에 접촉할 때 발생하는 접안에너지는 해당선박의 접안속도에 가장 큰 영향을 받는다. 접안속도가 과다할 경우 부두에 접촉하는 사고로까지 이어질 수 있으므로 각각의 부두 특성에 맞는 적절한 접안속도를 설계하는 것이 중요하다. 선박접안속도의 경우, 일반적으로 대수정규분포를 따른다고 가정하고 있으나 국내에서는 이에 대한 검증이나 연구가 없어 해외의 사례를 바탕으로 설계접안 속도를 설정하고 있는 상황이다. 이에 본 연구에서는 부두의 선박접안속도를 설계하기 위한 통계학적인 접근으로 접안속도의 실측데이터를 토대로 그 빈도수를 히스토그램으로 표현하여 각각의 확률분포도와 비교 분석하고, 확률분포에 대한 검정법으로 K-S (Kolmogorov-Smirnov Test) 검정, A-D(Anderson-Darling) 검정, Q-Q(Quantile-Quantile) Plot 등을 이용하여 접안속도 분포에 적합한 확률분포도를 확인하였다. 분석 결과, 선박접안속도의 빈도분포는 일반적으로 알려진 대수정규분포 뿐만 아니라 Weibull 분포와 적합한 형태를 보이는 것을 알 수 있었다. 추가적으로 본 연구에서는 초과확률 개념에서의 접안속도의 예측치를 구하여 구해진 1/1000, 1/10000의 접안속도 예측치를 설계접안속도의 참고자료로 제안하고자 한다.