• Journal of the Korean School Mathematics Society
• /
• v.21 no.2
• /
• pp.141-160
• /
• 2018

In order to propose effective learning methods to teach basic mathematics course for students of business administration, we conducted the survey on recognition and attitude on mathematics subjects, and analyzed academic achievements of the business mathematics as a basic mathematics course in relation to the results of the survey. First, we investigated learning contents and problems difficult for students to understand in the course, and presented the instructional method and significance of them with examples. These learning contents and problems were collected from the students using the mathematics cafe. Furthermore, we analyzed types of the incorrect answers on the midterm and final examinations in the business mathematics. Although it is difficult to generalize the finding to all of the business administration students due to differences in academic level and educational environment, much work has been put in to present learning method of the business mathematics for students of business administration.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.6A
• /
• pp.651-659
• /
• 2004

The Fast Handover protocol ［1］ provides seameless handover in wireless If networks by minimizing handover latency, which uses anticipation based on layer 2 (L2) trigger information. Therefore, it incurs higher signaling costs compared with the basic Mobile U protocol. Furthermore, since the L2 trigger is based on fluctuating wireless channel states, the handover anticipation may sometimes be incorrect. In the case of incorrect anticipation, unnecessary buffer space may be used for the purpose of providing a smooth handover. Therefore, it is essentical to analyze these overhead costs, in order to evaluate and compare the performance of Fast Handover with that of the basic Mobile U protocol. In this paper, we analyzed the overhead associated with Fast Handover including the signaling cost and the packet delivery cost. We formulated these costs based on a timing diagram and compared Fast Handover with basic Mobile Ipv6 in terms of their packet loss rates and buffer requirements. Also, we studied the impact of the L2 triggering time on the total overhead cost.

• Journal of the Korea Convergence Society
• /
• v.8 no.5
• /
• pp.13-17
• /
• 2017

Existing Speech feature extracting method in speech Signal, there are incorrect recognition rates due to incorrect speech which is not clear threshold value. In this article, the modeling method for improving speech recognition performance that combines the feature extraction for speech and silence characteristics normalized to the non-speech. The proposed method is minimized the noise affect, and speech recognition model are convergence of speech signal feature extraction to each speech frame and the silence feature normalization. Also, this method create the original speech signal with energy spectrum similar to entropy, therefore speech noise effects are to receive less of the noise. the performance values are improved in signal to noise ration by the silence feature normalization. We fixed speech and non speech classification standard value in cepstrum For th Performance analysis of the method presented in this paper is showed by comparing the results with CHMM HMM, the recognition rate was improved 2.7%p in the speech dependent and advanced 0.7%p in the speech independent.

• Journal of the Korean earth science society
• /
• v.25 no.4
• /
• pp.222-231
• /
• 2004

The purpose of this study is to analyze the seventh curriculum textbooks and teacher's guides of high school science courses in relation to the generation (mechanism) of magma in subduction boundary and find the incorrect descriptions of the texts and the figures (illustrations) and then suggest some improved schemes. According to the result there are many discrepancies in definition of 'magma' among the textbooks and further little scientific explanations about the formation mechanism of magma in most textbooks, and even no descriptions about that. In addition, the figures are inconsistent with the description of the text and also have some incorrect depiction which might contribute to the forming and reinforcing misconceptions about Plate Tectonics as well as a volcanic activity in subduction boundary. On the basis of the previous researches, therefore, some improved schemes (text descriptions and figures) are suggested. The results of this study should be used as a reference for publishing science textbook, developing science curriculum, and teaching effectively in the high school.

• The Mathematical Education
• /
• v.56 no.1
• /
• pp.63-80
• /
• 2017

By analysing the examination papers from third grade high school students, we classified the errors occurred in the problem solving process of high school 'Geometry and Vectors' into several types. There are five main types - (A)Insufficient Content Knowledge, (B)Wrong Method, (C)Logical Invalidity, (D)Unskilled Expression and (E)Interference.. Type A and B lead to an incorrect answer, and type C and D cannot be distinguished by multiple-choice or closed answer questions. Some of these types are classified into subtypes - (B1)Incompletion, (B2)Omitted Condition, (B3)Incorrect Calculation, (C1)Non-reasoning, (C2)Insufficient Reasoning, (C3)Illogical Process, (D1)Arbitrary Symbol, (D2)Using a Character Without Explanation, (D3) Visual Dependence, (D4)Symbol Incorrectly Used, (D5)Ambiguous Expression. Based on the these types of errors, answers of each problem was analysed in detail, and proper ways to correct or prevent these errors were suggested case by case. When problems that were used in the periodical test were given again in descriptive forms, 67% of the students tried to answer, and 14% described flawlessly, despite that the percentage of correct answers were higher than 40% when given in multiple-choice form. 34% of the students who tried to answer have failed to have logical validity. 37% of the students who tried to answer didn't have enough skill to express. In lessons on curves of secondary degree, teachers should be aware of several issues. Students are easily confused between 'focus' and 'vertex', and between 'components of a vector' and 'coordinates of a point'. Students often use an undefined expression when mentioning a parallel translation. When using a character, students have to make sure to define it precisely, to prevent the students from making errors and to make them express in correct ways.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.5
• /
• pp.457-463
• /
• 2015

This paper presents the need for the concept of collective intelligence based system for the timely learning and incorrect notes show the utilization and satisfaction. The old wrong answer note system is characterized by the provision of uniform right answer explanations for the questions whose answers were wrong by checking whether the evaluation items were answered right or wrong. The characteristic requires a lot of improvements in terms of wrong answer analysis and feedback since it cannot properly receive feedback on the items that a learner got right by luck in spite of poor understanding of them and on the errors in the selection process of wrong answers by individual learners. The SERO wrong answer note was designed to propose new ways to identify and capture such "score errors" and compensate for the practical weaknesses of learners. The Stability Emergency Risk Opportunity (SERO) wrong answer note is based on a method of categorizing and analyzing evaluation items answered by the examinee into four types (S, E, R and O type), and commentary correct as well as incorrect answers by presenting a variety of commentary notes using the collective intelligence of the study show that satisfaction is high.

• School Mathematics
• /
• v.8 no.3
• /
• pp.265-290
• /
• 2006

The purpose of this study is to search an effective teaching & learning program by examining how much does Excel affect on problem solving of linear function. This study was based on qualitative case study. Teaching experiment was performed for seven periods with five students in 8th graders. Pre and posts tests were attempted to analyze the changes of student's ability on problem solving of linear function. The analysis of tests were performed in category with correct process-object perspective, near process-object perspective, incorrect process-object perspective. According to this study, the subjects showed an improvement on problem solving perspective of linear function. This meant that lessons using Excel had influenced on the problem solving of linear function. We noticed that exploring the learning environment with Excel could supplement paper-and-pencil environment. We believed that Excel with an intuitive dynamic and explorative skills can play a role in scaffolding to support problem solving of linear function.

• Journal of the Korean Institute of Navigation
• /
• v.5 no.2
• /
• pp.1-39
• /
• 1981

A doppler log is the typical device which can measure the ship's speed over the ground directly, by means of doppler effect of the underwater ultrasonic wave, which involves the error due to the sea bottom inclination, the trim and the incorrect transducer installation etc. The present doppler log adopts a single transducer, faced in the direction of themain beam, and therefore it is unable to correct the beam direction to eliminate the above mentioned error. Moreover, the frequencyis also limitted in a comparatively high range for getting a sharp beam with single transducer, and the speed over the ground can not be detectable at the deep sea, for an instance, over 200 meters. This paper describes a theoretical consideration for the doppler log error and an analysis by a computer on the observed speed data by a full size model ship. The result is verified that the most of doppler log error is caused by the ultrasonic beam angle of transducer. To eliminate the doppler log error due to the incorrect transducer installation and also to sharpen the beam for lower frequency range to expand measurable sea depth, this paper proposes a method of controlling the directivity adopting a linear transducer array and of controlling the directivity by the control of exciting current, and investigates by the computer simulation and make experiment with magnetostrictive ferrite transducer of 28, 50 and 75KHz. The experimental results are shown well coincide with the measured ones, and they are revealed that in case where the transducer interval is greater than 1 wavelength, the effective control of the beam direction is hardly performed with keeping adequate beam width and side lobe level. It is concluded that 6-elements array with inter element space of a half wavelength can make comparatively sharp beam and low side lobe level. The results obtained here will contribute very much to the improvement of the performance of doppler log.

• Education of Primary School Mathematics
• /
• v.25 no.3
• /
• pp.213-232
• /
• 2022

With the importance of number line in learning fractions, this study investigated how 4th grade students understand fractions and its operations in number line. The questionnaire consisted 22 items which were related to representing fractions, comparing the size of fractions, and operating addition and subtraction of fractions. Both structured number line and sub-structured number line were presented in the items. As results of the study, the overall success rates were not high and even some items showed higher incorrect answer rates than the success rates. Also, the students showed a difficulty in solving non-structured number line tasks. It was also noticeable that students showed several types of incorrect answers, which means that students had incomplete understanding of both fractions and number line. This paper is expected to shed light on elementary students' understanding of fractions and number line and to provide implications of how to deal with number line in teaching and learning fractions in the elementary school.

• Journal of The Geomorphological Association of Korea
• /
• v.26 no.4
• /
• pp.123-140
• /
• 2019

This study analyzed problems of interpretive signs along Eorimok-Yeongsil Trail on Mt. Hallasan National Park, focusing on factors of distracting visitor's attention from reading and understanding the signs. Eorimok-Yeongsil Trail has a total of 86 signs, and according to their purpose and content, they are classified into thirteen general signs, sixteen location signs, nine safety signs and forty-eight interpretive signs. Interpretive signs provide visitors with information and explanations about the nature and human resources of Mt. Hallasan as well as enhancing the opportunity for self-guided interpretation. The contents of interpretive signs of Eorimok-Yeongsil Trail are composed of landscapes, flora and fauna, topography, geology, history and culture, of which 70.8% of the total are related to plants and animals. Interpretive signs on the Eorimok-Yeongsil Trail do not attract visitors' attention because of the low readability, inappropriate locations and frequent errors in translation from Korean into other languages. The causes of low readability of interpretive signs include thirty-six physically damaged and faded signs, twenty-two improper font sizes and misuse of color schemes and five unclear description signs. The reasons for the incorrect locations include twenty-two long distances from the trails, twenty-one inadequate heights and fifteen inconsistencies in descriptions and locations. Problems with English use include eight grammar and spelling errors, twenty-one incorrect translations, and twenty-six English names missing.