• Korean Journal of Mathematics
• /
• v.14 no.1
• /
• pp.35-46
• /
• 2006

The concept of convolution is a fundamental mathematical concept in a wide variety of disciplines and applications including probability, image processing, physics, and many more. The visualization of convolution for the continuous case is generally predetermined. On the other hand, the convolution structure embedded in the discrete case is often subtle and its visualization is non- trivial. This paper purports to develop the CAS techniques in visualizing the logical structure in the concept of a discrete convolution.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.14 no.1
• /
• pp.88-96
• /
• 1989

General measure in the reliability is the k-terminal reliability, which is the probability that the specified vertices are connected by the working edges. To compute the k-terminal reliability components are usually assumed to be statistically independent. In this study the modeling and analysis of the k-terminal reliability are investigated when dependency among components is considered. As the size of the network increases, the number of the joint probability parameter to represent the dependency among components is increasing exponentially. To avoid such a difficulty the structured-event-based-reliability model (SERM) is presented. This model uses the combination of the network topology (physical representation) and reliability block diagram (logical representation). This enables us to represent the dependency among components in a network form. Computational algorithms for the k-terminal reliability in SERM are based on the factoring algorithm Two features of the ractoring algorithm are the reliability preserving reduction and the privoting edge selection strategy. The pivoting edge selction strategy is modified by two different ways to tackle the replicated edges occuring in SERM. Two algorithms are presented according to each modified pivoting strategy and illustrated by numerical example.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.10
• /
• pp.2421-2433
• /
• 1997

In this paper, based on the relative logical storage cost of each movie by the difference of service request probability, we propose and implement the SDU(Separate Data Use) method and the EDU(Existing Data Use) method to provide FF(Fast Forward) and FR(Fast Reverse) function in efficiently through analysing MPEG bit stream and frame characteristics. By selecting and applying the FF/FR function providing method based on the service request probability of movie, the proposed method can reduce the cost of FF/FR functions for total serviced movies.

• Journal of the Korean School Mathematics Society
• /
• v.20 no.4
• /
• pp.387-404
• /
• 2017

In this paper, in the last 4 years(2014~2017 school year), we classified the probability and statistical items based on the evaluation scope of the mathematics subject content knowledge which were presented by the Korea Institute for Curriculum and Evaluation, and the classified items were analyzed. As a result, First, in order to induce normalization of the probability and statistical curriculum, four assessment field should be evenly distributed. Second, integrated thinking and comprehensive analytical thinking assessment is required. Third, item an epilogue should be used to measure mathematical thinking and logical competence. Fourth, the ratio of the number of items in probability and statistics to the number of that was 7.7%~10.0%, and the ratio according to the item weighting was 5.0%~7.5%. Fifth, it maintains the policy of stabilizing a good the level of difficulty of the items. Finally, probability and statistical assessment should focus on measuring problem solving ability from an inductive point of view.

• Wind and Structures
• /
• v.26 no.1
• /
• pp.45-56
• /
• 2018

Wind damage of urban trees arises to be a serious issue especially in the typhoon-prone areas. As a family of tree species widely-planted in Southeast China, the structural behaviors of Plane tree is investigated. In order to accommodate the complexities of tree morphology, a fractal theory based finite element modeling method is proposed. On-site measurement of Plane trees is performed for physical definition of structural parameters. It is revealed that modal frequencies of Plane trees distribute in a manner of grouped dense-frequencies; bending is the main mode of structural failure. In conjunction with the probability density evolution method, the fragility assessment of urban trees subjected to wind excitations is then proceeded. Numerical results indicate that small-size segments such as secondary branches feature a relatively higher failure risk in a low wind level, and a relatively lower failure risk in a high wind level owing to windward shrinks. Besides, the trunk of Plane tree is the segment most likely to be damaged than other segments in case of high winds. The failure position tends to occur at the connection between trunk and primary branches, where the logical protections and reinforcement measures can be implemented for mitigating the wind damage.

• The Korean Journal of Applied Statistics
• /
• v.23 no.6
• /
• pp.1201-1208
• /
• 2010

In teaching probability and statistics classes, we should increase efforts to develop examples that enhance teaching methodology in delivering more meaningful knowledge to students. Sports is one field that provides a variety of examples and World Cup Soccer events are a treasure house of many interesting problems. Teaching, using examples from this field, is an effective way to enhance the interest of students in probability and statistics because World Cup Soccer is a matter of national interest. In this paper, we have suggested several examples pertaining to counting the number of cases and computing probabilities. These examples are related to many issues such as possible scenarios in the preliminary round, victory points necessary for each participant to advance to the second round, and the issue of grouping teams. Based on a simulation using a statistical model, we have proposed a logical method for computing the probabilities of proceeding to the second round and winning the championship for each participant in the 2010 South Africa World Cup.

• Journal of The Korean Association For Science Education
• /
• v.25 no.7
• /
• pp.787-793
• /
• 2005

The purposes of this study were to investigate the development of probabilistic thinking in relation to the cognitive level of elementary school students and to analyze the effects of probability activities in Thinking Science(TS) program on the development of probabilistic thinking. 152 6th grade elementary school students compiled the sample group which was divided into an experimental group and a control group. Probability activities in TS program were used with the experimental group, while the normal curriculum was conducted with the control group. Both the experimental and control group were assessed with Science Reasoning Task II and a probabilistic thinking test before execution of this investigation and were post-tested with probabilistic thinking test after the project period was complete. Results of this study showed that the students in the concrete operational stage and transitional stage used subjective strategy together with quantitative strategy in probability problem-solving, and students in the early formal operational stage used quantitative strategy in probability problem-solving. It was also found that the higher the cognitive level of students, the higher the probabilistic thinking level. The probability activities of the TS program influenced the development of probabilistic thinking of elementary school students. Assessing the development of probabilistic thinking on the basis of the cognitive level found that the level of effectiveness was significantly higher for students in the early concrete operational stage and transitional stage than students in any other stage.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.15 no.2
• /
• pp.161-172
• /
• 2017

To evaluate radiological impact from the operation of a low- and intermediate-level radioactive waste disposal facility, a logical presentation and explanation of expected accidental scenarios is essential to the stakeholders of the disposal facility. The logical assessment platform and procedure, including analysis of the safety function of disposal components, operational hazard analysis, operational risk analysis, and preparedness of remedial measures for operational safety, are improved in this study. In the operational risk analysis, both design measures and management measures are suggested to make it possible to connect among design, operation, and safety assessment within the same assessment platform. For the preparedness of logical assessment procedure, classification logic of an operational accident is suggested based on the probability of occurrence and consequences of assessment results. The improved assessment platform and procedure are applied to an operational accident analysis of the Korean low- and intermediate-level radioactive waste disposal facility and partly presented in this paper.

• Journal of Educational Research in Mathematics
• /
• v.15 no.3
• /
• pp.315-334
• /
• 2005

The purpose of this study is to find out the implications on when and how the correlation concept can be taught. we investigate the development time and method of the concept in a statistical perspective those initially have discussed in psychology by Piaget. We first reviewed the 1958 research by Inhelder and Piaget. It was the first one which researched the development of the correlation and has become the foundation of psychological perspective. According to them, the correlation concept needs proportional and probability concept ahead of its development and argued on the coefficient of correlation based on formal and logical position. However, from a statistical perspective, the correlation concept is a part of the distribution concept. So, the level of the correlation concept grows from the comparison of conditional distributions to the conditional probability distribution where the proportional concept and probability concept are applied. As reviewed through the literature, we found that 11-12 years old students in early formal operation stage reasoned about correlation through the comparison of conditional distributions. In our study, we argue that we need to consider the possibility of beginning didactic mediation for correlation concept earlier and the method approaching it in a distribution perspective.

• School Mathematics
• /
• v.11 no.3
• /
• pp.513-526
• /
• 2009

The purpose of this paper intuitively shows the exact and logical explanation of Independent Event and Dependent Event. In actual classrooms, teachers have difficulty in describing the connection between those events and real life. Some teachers have wrong perceptions on the definition of those events. For example, they may not realize exactly what P(B A)=P(B) means and may not explain intuitively the original meaning of why it is independent event. Also they believe that Independent Event and Dependent Event do not always match with real life. This paper, therefore, tries to prove intuitively the exact meanings of those events in the Verbal Form with some examples and it proves that those events exactly match with real life. It is expected that this paper will greatly contribute to the improvement of probability education.