• Journal of Engineering Education Research
• /
• v.15 no.5
• /
• pp.19-24
• /
• 2012

Robots have been attracting students' interest recently. Therefore, they are a good way to motivate to study related subjects. However, there are difficulties in teaching general students because a wide background is required to understand the fundamentals of robotics. In order to teach robotics fundamentals to beginners in a short period, an effective experimental class, including several phased experiments, is proposed in this paper. A portable two-DOF robot arm system with servo motors was developed for experiments, and the operation method based on kinematics was introduced for its operation. The effectiveness of the class was investigated by using a questionnaire after carrying it out in a university class for junior students.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.4
• /
• pp.73-80
• /
• 2016

Most fault prediction models have class imbalance problems because training data usually contains much more non-fault class modules than fault class ones. This imbalanced distribution makes it difficult for the models to learn the minor class module data. Data imbalance is much higher when severity-based fault prediction is used. This is because high severity fault modules is a smaller subset of the fault modules. In this paper, we propose severity-based models to solve these problems using the three sampling methods, Resample, SpreadSubSample and SMOTE. Empirical results show that Resample method has typical over-fit problems, and SpreadSubSample method cannot enhance the prediction performance of the models. Unlike two methods, SMOTE method shows good performance in terms of AUC and FNR values. Especially J48 decision tree model using SMOTE outperforms other prediction models.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.1605-1607
• /
• 2000

In this paper, the design of class AB BiCMOS log-domain filter for low-voltage and low-power was proposed. This filter is consist of a log-domain integrator using folded junctions with capacitor connected to emitter and it's class AB structure. A comparison between the proposed class AB BiCMOS log-domain filter and classical class A BiCMOS log-domain filter is drawn on the basis of SNR, THD and the frequency response. This comparison shows proposed filter are more than good SNR, THD and frequency characteristics than more class A log-domain filter for low voltage and low power.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.2B
• /
• pp.11-20
• /
• 2005

Strict priority scheduling scheme is a good candidate for the implementation of service differentiation in an Internet because of simplicity in implementation and the capability to guarantee the delay requirement of the highest class of traffic. However, it is also blown that strict priority starves the lower-class traffic at the cost of prioritizing the higher-class traffic. The purpose of this work is to propose an analytic method which can estimate the average delay performance of Diffserv service architecture and shows that strict priority scheme does not sacrifice the lower class traffic over a diverse condition of the load. From the numerical experiments for three-class Diffserv network we validate our argument that strict priority scheme may be applied to a service differentiation scheme for the future Internet.

• Journal of Korean Institute of Industrial Engineers
• /
• v.40 no.4
• /
• pp.404-414
• /
• 2014

Yield prediction is important to manage semiconductor quality. Many researches with machine learning algorithms such as SVM (support vector machine) are conducted to predict yield precisely. However, yield prediction using SVM is hard because extremely imbalanced and big data are generated by final test procedure in semiconductor manufacturing process. Using SVM algorithm with imbalanced data sometimes cause unnecessary support vectors from major class because of unselected support vectors from minor class. So, decision boundary at target class can be overwhelmed by effect of observations in major class. For this reason, we propose a under-sampling method with minor class based SVM (MCSVM) which overcomes the limitations of ordinary SVM algorithm. MCSVM constructs the model that fixes some of data from minor class as support vectors, and they can be good samples representing the nature of target class. Several experimental studies with using the data sets from UCI and real manufacturing process represent that our proposed method performs better than existing sampling methods.

• Journal of The Korean Association For Science Education
• /
• v.34 no.1
• /
• pp.10-20
• /
• 2014

This study compares the perceptions of elementary gifted child and science teacher in a science class for the gifted. In order to explore the research problem, students and teachers answered a written semi-structured questionnaire and participated in interviews regarding the gifted science class. The data was collected and analyzed. Science teachers recognized the characteristics of a good science class, especially in terms of educational content and teaching methodology. First, they suggested promoting inquiry skills, presenting a challenging task in atypical topic selection, student-centered curriculum, and controlling the pace of learning to recognize individual differences. Second, in terms of the science class skills and attitudes category, teachers recommended raising mutual satisfaction through vigorous interaction within a permissible atmosphere. Finally, science teachers need to strive for continued professional growth. Gifted children, meanwhile, want to investigate a wide range of topics without time constraints. Additionally, they may have to explore challenging topics further. They prefer to act like scientists in that they enjoy group activities, communication and cooperation. In particular, they want to be evaluated by others in a totally embedded assessment. Gifted children also expect teachers to understand the life circumstances and needs of the students. In addition, they asked for teachers to respect individual experiments and to show them how to safely use new equipment or research methods. As a result, gifted children and science teachers have to recognize the differences of opinion concerning a good science class for the gifted. This study can help formulate strategies to establish quality management of materials in gifted science classes.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.5 s.347
• /
• pp.94-103
• /
• 2006

Ethernet passive optical network (EPON) has drawn many attention as a promising access network technology for FTTH because it can provide a high bandwidth with a low cost. Since the uplink bandwidth in the EPON system is shared by many users, it is necessary for an EPON system to have an efficient bandwidth allocation mechanism. To support QoS in EPON, the previous bandwidth allocation schemes employ strict priority queueing (SPQ). Since SPQ gives unlimited priority to higher service class, the QoS of lower service classes gets worse. In this paper, we propose Class Gated DBA (Dynamic Bandwidth Allocation) algorithm in which the bandwidth is requested / granted in a service class basis. To avoid the monopoly in bandwidth usage by higher classes the maximum bandwidth that is allocate to each service class is limited (fairness between services classes). In addition, to avoid the monopoly in bandwidth usage by some particular users, each ONU runs fairness bandwidth allocation algorithm within each service classes. Through computer simulations, it is verified that the proposed algorithm achieves a good level of QoS, and at the same time maintains a good level of fairness between both service classes and users.

• Journal of the Korean School Mathematics Society
• /
• v.19 no.3
• /
• pp.277-289
• /
• 2016

This study is to figure out the activity of individual education with the note-taking in math class and correction and supportive explanations on attitudes toward learning of underachievers in mathematics in the second-year class of high school. This study has begun on the basis of the judgement that the note-taking especially correction and supportive explanations could help the underachievers in mathematics focus in class and develop good learning habits, and besides, students make a good relationship with teacher. According to this result, Many researches and exertions need to inform every student that mathematics is open and doing mathematics is a happy object. if the students who are underachievers were given the chance to organize their learning by themselves in the class with note-taking and correction and supportive explanations in the long-term, it should be effective enough to change their attitudes toward learning.

• Journal of Korean Elementary Science Education
• /
• v.38 no.1
• /
• pp.31-42
• /
• 2019

Through the criticism and evaluation of different classes teaching the same lesson topic, this study compared the viewpoints by two ways between two groups including pre-service and experienced teachers. Through free-style criticism, this study analyzed the differences between pre-service and experienced teachers' areas of attention. Through criteria-based analysis, the study analyzed the judgement of each area and the criteria of each judgement. The results of the study found that pre-service teachers criticised more limited areas, but somewhat more positive than their experienced teacher counterparts. Also, pre-service teachers did not observe thoroughly whether or not the teacher was well-informed of the science content, the sequence of curriculum, and whether or not meaningful interaction had occurred. As well as, pre-service teachers were not actually feel importance of student-oriented lessons, and they could not look room and materials are useful to students on students' sides. Additionally, pre-service teachers thought highly of lessons which were connected to other subjects rather than connected to daily life. Therefore, to notice diverse areas in the class, pre-service teachers need to criticise lessons using a diverse criterion. Also, pre-service teachers realized simple questions and that mechanical group activities are not always effective and that they need to think how to improve meaningful interaction. Moreover, they have to perceive that an inquiry-oriented student-lead approach is very important. Lastly, pre-service teachers have to closely consider the room efficiency and materials available to the students, and they must internalize that science class has to be connected with daily life.

• The Journal of Korean Association of Computer Education
• /
• v.20 no.4
• /
• pp.15-25
• /
• 2017

The purpose of this study is to verify the effectiveness of the flipped class by comparing Python programming classes divided into flipped class and general class. The participants who participated in each class had 36 students, so that they could participate in the class without knowing the difference of the class method. The students's academic achievement was applied the two groups with similar test items, and then the overall achievement were compared. The analysis showed that the achievements in flipped class in the basic grammar and intermediate grammar were higher than those in the general class. As a result of gender achievement analysis, there was no effect on the type of instruction. However, male student were generally higher in academic achievement. In conclusion, flipped class in the programming is a good way to improve students' understanding.