• 한국학교수학회논문집
• /
• 제25권4호
• /
• pp.353-374
• /
• 2022

본 연구는 4차 산업시대를 맞아 코딩을 포함한 교수·학습이 강조됨에 따라 코딩수업에서 수학 교수·학습의 효과를 파악하고자 수행되었다. 이를 위해 경기도 D 중학교 1학년 학생들 32명이 스크래치를 활용한 7차시 프로그램에 참여하여, 그들의 활동자료는 컴퓨터에 매 차시 저장되었고, 연구자는 관찰일지를 매주 작성하였다. 중학교 등식의 성질에서 이렇게 수집된 자료를 통해 연구자는 도구화 수준에 대해 개별 학생의 수준을 조사하고, 학생의 컴퓨터프로그래밍 자기효능감을 사전과 사후 검사를 통해 조사하였다. 학생들의 도구화는 다양하게 나타났는데 연구가 시작된 시점에는 도구화의 제 3 또는 4수준에 해당하는 학생이 9%에 불과하였지만 연구마무리 시점에는 80%를 상회하였다. 학생들의 컴퓨터프로그래밍에 대한 자기효능감은 유의한 수준으로 향상되었다.

• Journal of applied mathematics & informatics
• /
• 제42권3호
• /
• pp.635-646
• /
• 2024

In this research work, we introduce and investigate four innovative types of soft spaces, pushing the boundaries of traditional spatial concepts. These new types of soft spaces are named as soft T_b space, soft T^#_b space, soft T^##_b space and soft_αT^#_b space. Through rigorous analysis and experimentation, we uncover and propose distinct characteristics that define and differentiate these spaces. In this research work, we have established that every soft $T_{\frac{1}{2}}$ space is a soft _αT^#_b space, every soft T_b space is a soft _αT^#_b space, every soft T^#_b space is a soft _αT^#_b space, every soft T_b space is a soft T^#_b space, every soft T^#_b space is a soft T^##_b space, every soft $T_{\frac{1}{2}}$ space is a soft ^#T_b space and every soft T_b space is a soft #T_b space.

• 한국초등수학교육학회지
• /
• 제14권2호
• /
• pp.287-314
• /
• 2010

알고리즘을 지도하는 전통적인 방법은 우선 '표준 알고리즘'을 완성된 형태로 제시하고 이어서 간단한 사례를 통하여 이해한 다음, 보다 일반적인 문제에 적용함으로써 표준 알고리즘을 연습하는 형태이다. 그러나 이 방법은 표준 알고리즘에 지나치게 집중되어 있다는 문제점과 함께, 학생 스스로 문제에 적합한 알고리즘을 선택하거나 알고리즘 자체를 개발하는 경험을 제공하지 못한다는 제한점을 갖고 있다. 이 논문에서는 자연수 곱셈 알고리즘의 다양성을 활용하여 학생 스스로 알고리즘을 개발하고 발명할 수 있도록 지도하는 방안을 상세하게 구안하였고, 그에 따른 교수실험을 통하여 초등학교 3학년 학생의 곱셈 알고리즘에 대한 이해 과정을 분석하였다. 그 결과는 첫째, 실험적인 지도안으로 학습한 실험반은 자리값의 원리와 분배법칙의 이해에 있어서 비교반보다 높은 성취를 보였으나, 계산 능력에 있어서는 그렇지 못했다. 둘째, 비교반은 물론 실험반에서도 표준 알고리즘의 선호도가 가장 높았으며, 실험반에서는 표준 알고리즘 다음으로 격자곱셈의 선호도가 높은 것으로 나타났다. 격자 곱셈을 교육 소재로 활용하는 것을 적극 고려할 필요가 있다. 셋째, 비례표는 그것이 가지는 이론적인 장점에도 불구하고 우리나라 초등학교 3학년 학생이 배우기에는 다소 무리가 따르는 것으로 나타났다.

• Journal of Theoretical and Applied Mechanics
• /
• 제3권1호
• /
• pp.16-33
• /
• 2002

A concept of hierarchical modeling, the newest modeling technology. has been introduced early In 1990. This nu technology has a goat potential to advance the capabilities of current computational mechanics. A first step to Implement this concept is to construct hierarchical models, a family of mathematical models which are sequentially connected by a key parameter of the problem under consideration and have different levels in modeling accuracy, and to investigate characteristics In their numerical simulation aspects. Among representative model problems to explore this concept are elastic structures such as beam-, arch-. plate- and shell-like structures because the mechanical behavior through the thickness can be approximated with sequential accuracy by varying the order of thickness polynomials in the displacement or stress fields. But, in the numerical analysis of hierarchical models, two kinds of errors prevail: the modeling error and the numerical approximation errors. To ensure numerical simulation quality, an accurate estimation of these two errors Is definitely essential. Here, a local a posteriori error estimator for elastic structures with thin domain such as plate- and shell-like structures Is derived using element residuals and flux balancing technique. This method guarantees upper bounds for the global error, and also provides accurate local error Indicators for two types of errors, in the energy norm. Comparing to the classical error estimators using flux averaging technique, this shows considerably reliable and accurate effectivity indices. To illustrate the theoretical results and to verify the validity of the proposed error estimator, representative numerical examples are provided.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권5호
• /
• pp.1328-1342
• /
• 2013

Searchable encryption is a cryptographic protocol for searching a document in encrypted databases. A simple searchable encryption protocol, which is capable of using only one keyword at one time, is very limited and cannot satisfy demands of various applications. Thus, designing a searchable encryption with useful additional functions, for example, conjunctive keyword search, is one of the most important goals. There have been many attempts to construct a searchable encryption with conjunctive keyword search. However, most of the previously proposed protocols are based on public-key cryptosystems which require a large amount of computational cost. Moreover, the amount of computation in search procedure depends on the number of documents stored in the database. These previously proposed protocols are not suitable for extremely large data sets. In this paper, we propose a new searchable encryption protocol with a conjunctive keyword search based on a linked tree structure instead of public-key based techniques. The protocol requires a remarkably small computational cost, particularly when applied to extremely large databases. Actually, the amount of computation in search procedure depends on the number of documents matched to the query, instead of the size of the entire database.

• Steel and Composite Structures
• /
• 제34권3호
• /
• pp.377-391
• /
• 2020

A concrete filled steel tube (CFT) column with stiffeners has preferable behavior subjected to axial loading condition due to delay local buckling of the steel wall than traditional CFT columns without stiffeners. Welding lines in welded built-up steel box columns is expected to behave as longitudinal stiffeners. This study has presented a numerical investigation into the behavior of built-up concrete filled steel tube columns under axial pressure. At first stage, a finite element model (FE) has been built to simulate the behavior of built-up CFT columns. Comparing the results of FE and test has shown that numerical model passes the desired conditions and could accurately predict the axial performance of CFT column. Also, by the raise of steel tube thickness, the load bearing capacity of columns has been increased due to higher confinement effect. Also, the raise of concrete strength with greater cross section is led to a higher load bearing capacity compared to the steel tube thickness increment. In CFT columns with greater cross section, concrete strength has a higher influence on load bearing capacity which is noticeable in columns with more welding lines.

• Steel and Composite Structures
• /
• 제34권3호
• /
• pp.347-359
• /
• 2020

The objective of this study is to experimentally scrutinize the axial performance of built-up concrete filled steel tube (CFT) columns composed of steel plates. In this case, the main parameters cross section types, compressive strength of filled concrete, and the effect of welding lines. Welded built-up steel box columns are fabricated by connecting two pieces of cold-formed U-shaped or four pieces of L-shaped thin steel plates with continuous penetration groove welding line located at mid-depth of stub column section. Furthermore, traditional square steel box sections with no welding lines are investigated for the comparison of axial behavior between the generic and build-up cross sections. Accordingly, 20 stub columns with thickness and height of 2 and 300 mm have been manufactured. As a result, welding lines in built-up specimens act as stiffeners because have higher strength and thickness in comparison to the plates. Subsequently, by increasing the welding lines, the load bearing capacity of stub columns has been increased in comparison to the traditional series. Furthermore, for specimens with the same confinement steel tubes and concrete core, increment of B/t ratio has reduced the ductility and axial strength.

• Advances in nano research
• /
• 제8권3호
• /
• pp.191-202
• /
• 2020

The article brings the study of nonlocal, surface and the couple stress together to apparent the frequency retaliation of FG nanobeams (Functionally graded). For the examination of frequency retaliation, the article considers the accurate spot of neutral axis. This article aims to enhance the coherence of proposed model to accurately encapsulate the significant effects of the nonlocal stress field, size effects together with material length scale parameters. These considered parameters are assimilated through what are referred to as modified couple stress as well as nonlocal elasticity theories, which encompasses the stiffness-hardening and softening influence on the nanobeams frequency characteristics. Power-law distribution is followed by the functional gradation of the material across the beam width in the considered structure of the article. Following the well-known Hamilton's principle, fundamental basic equations alongside their correlated boundary conditions are solved analytically. Validation of the study is also done with published result. Distinct parameters (such as surface energy, slenderness ratio, as nonlocal material length scale and power-law exponent) influence is depicted graphically following the boundary conditions on non-dimensional FG nanobeams frequency.

• 한국생물정보학회:학술대회논문집
• /
• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
• /
• pp.313-318
• /
• 2005

Estimating the reliability of protein-protein interaction data sets obtained by high-throughput technologies such as yeast two-hybrid assays and mass spectrometry is of great importance. We develop a maximum likelihood estimation method that uses both protein localization and gene expression data to estimate the reliability of protein interaction data sets. By integrating protein localization data and gene expression data, we can obtain more accurate estimates of the reliability of various interaction data sets. We apply the method to protein physical interaction data sets and protein complex data sets. The reliability of the yeast two-hybrid interactions by Ito et al. (2001) is 27%, and that by Uetz et at.(2000) is 68%. The reliability of the protein complex data sets using tandem affinity purification-mass spec-trometry (TAP) by Gavin et at. (2002) is 45%, and that using high-throughput mass spectrometric protein complex identification (HMS-PCI) by Ho et al. (2002) is 20%. The method is general and can be applied to analyze any protein interaction data sets.

• 대한수학회보
• /
• 제55권4호
• /
• pp.1189-1208
• /
• 2018

The aim of this paper is to study the class of ${\Lambda}$-constacyclic codes of length $2p^s$ over the finite commutative chain ring ${\mathcal{R}}_a=\frac{{\mathbb{F}_{p^m}}[u]}{{\langle}u^a{\rangle}}={\mathbb{F}}_{p^m}+u{\mathbb{F}}_{p^m}+{\cdots}+u^{a-1}{\mathbb{F}}_{p^m}$, for all units ${\Lambda}$ of ${\mathcal{R}}_a$ that have the form ${\Lambda}={\Lambda}_0+u{\Lambda}_1+{\cdots}+u^{a-1}{\Lambda}_{a-1}$, where ${\Lambda}_0,{\Lambda}_1,{\cdots},{\Lambda}_{a-1}{\in}{\mathbb{F}}_{p^m}$, ${\Lambda}_0{\neq}0$, ${\Lambda}_1{\neq}0$. The algebraic structure of all ${\Lambda}$-constacyclic codes of length $2p^s$ over ${\mathcal{R}}_a$ and their duals are established. As an application, this structure is used to determine the Rosenbloom-Tsfasman (RT) distance and weight distributions of all such codes. Among such constacyclic codes, the unique MDS code with respect to the RT distance is obtained.