• Journal of Internet Computing and Services
• /
• v.12 no.1
• /
• pp.119-130
• /
• 2011

As a de facto standard for system modeling, UML diagrams have been widely used in the industry. Of these, the class diagram is useful to visualize the classes and their relationships and thus directly influences the forward and reverse processes of system modeling and development. Many earlier studies have attempted to examine as to what impact the layout and complexity of the class diagram would have on the comprehension of system modeling. However, their findings have been equivocal and it is not easy to understand the effects of diagram layout. Accordingly this research relied on the guidelines of diagram layout suggested in the earlier studies and designed a 2 (layout) x 2 (complexity) factorial design to examine their impact on diagram comprehension. 47 subjects were participated in the experiment where class diagrams were provided differently in their layout and complexity. We found that a good layout was significantly more effective than the bad. Furthermore the results were significantly persistent in the complex group than the simple. However, there was no interaction effect between layout and complexity of the diagram.

• Journal of Power Electronics
• /
• v.17 no.4
• /
• pp.892-904
• /
• 2017

A design of a Class-E inverter with only one inductor and one capacitor is presented. It is operated at the optimal operation mode for domestic cooker. The design principle is based on the zero-voltage derivative switching (ZVDS) of the Class-E inverter with a parallel load network, which is a parallel resonant equivalent circuit. An induction load characterization is obtained from a large-signal excitation test bench, which is the key to an accurate design of the induction cooker system. Consequently, the proposed scheme provides a more systematic, simple, accurate, and feasible solution than the conventional quasi-resonant inverter analysis based on series load network methodology. The derivative of the switch voltage is zero at the turn-on transition, and its absolute value is relatively small at the turn-off transition. Switching losses and noise are reduced. The parameters of the ZVDS Class-E inverter for the domestic induction cooker must be selected properly, and details of the design of the components of this Class-E inverter need to be addressed. A 1,200 W prototype is designed and evaluated to verify the validation of the proposed topology.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.5 no.2
• /
• pp.93-99
• /
• 1985

All soil characteristics for 10,077ha of establishable grassland in 1984 were statistically summarized. Soils could be classified into 5 of Order, 7 Suborder, 11 Great group, 28 Subgroup, and 105 Series by the new comprehensive classification system. Distribution rate of farm houses managed the extent magnitude of 3.0ha was 70.8% and its total extent was 35.9%. Extent rate of uncultivated method was 71.3%. These soils were distributed with regard to hilly land and mountain foot slope at, 82.0, and to 0-30% slope at 66.9%. Soil texture was light such as sandy loam to loam at 85.0%, available soil depth more than 20cm at 97.8%, and gravel content less than 35% at 98.4%. Soil would be distributed in 67.3 of first class, 29.7 second class, and 3.0% third class for suitability. Mean values of pH, available $P_2O_5$, OM, Ca, Mg and K for topsoil were 5.6, 31ppm, 3.2%, 2.23me/100gr, 1.05me/100gr, and 0.37me/100gr, respectively.

• Journal of the Korean earth science society
• /
• v.26 no.1
• /
• pp.30-40
• /
• 2005

The purpose of this study is to analyze gifted students' perception of the teaching activities at the gifted science high school (Busan Science Academy), in Busan, Korea, and to investigate the science experiment class practice. In this study, a questionnaire about the curriculum courses, teaching strategies, and evaluation method of the school was administered to 139 gifted students. The verbal interactions during the science experiment class were audio and videotaped, transcribed, and analyzed. The results of this study are as follows: First, according to the gifted students' perception, the credits of specialized courses and advanced elective courses need to be increased and the credits of general courses need to be reduced. Second, teachers at this school mainly use teaching strategies such as lecture, group activities, and discussion; on the other hand, the students prefer diverse teaching strategies such as discussion, lecture, experiment, inquiring activities, and problem solving. Third, students prefer a writing test assessment rather than a written report assessment or portfolio assessment. Fourth, the patterns of verbal interaction were different depending on the level of the teachers' questions and interactions between the students in the experiment class facilitated students' inquiry.

• Journal of The Korean Association For Science Education
• /
• v.39 no.5
• /
• pp.669-679
• /
• 2019

In this study, we investigated how 'Scientific Inquiry Experiment,' a newly introduced subject under the 2015 revised curriculum, was implemented to identify the difficulties that science teachers face in the process of teaching the subject and to explore how to support them through online survey and interview methods. A questionnaire of the survey, which consisted of environmental factors of class, preparation and execution of class, teacher self-evaluation of class, and direction for the subject, was developed, and the online survey was requested with a response from one teacher per school from 1674 high schools nationwide. We analyzed the results from 814 teachers who answered all required questions, and we also conducted interviews and online advisory discussions to ensure the validity of our analysis. In the results of the study, teachers complained of lack of time for preparation and execution of the subject, and they demanded laboratory assistants and quality teaching materials. In addition, in order to achieve the goal of the subject, they agreed the necessity of using the 'block scheduling' though they also agreed the difficulties of its implementation. Meanwhile, the alteration of guidelines for evaluation, which was changed from 9-grade system to 3-grade system, was positively recognized by teachers. As a result of this change, the percentage of performance assessment increased in 2019 compared to 2018, but there were no significant changes in the number of 'hands-on activity.' Finally, we proposed ways to support 'scientific inquiry experiment'.

• Journal of the Korean Society of Earth Science Education
• /
• v.4 no.1
• /
• pp.43-56
• /
• 2011

The purpose of this study is to examine the effects of small group inquiry skills on improving science process skills and attitudes toward science in elementary school science. The research questions of this study were as follows. First, effects of small group inquiry skills on improving science process skills in elementary school science. Second, effects of small group inquiry skills on improving attitudes toward science in elementary school science. The subjects of this study is two classes from 6th grade elementary classes in Busan. The experiment class practiced small group inquiry skills, while the control class practiced self inquiry. To verify the effect of the experiment, ANOVA was conducted. The main findings of this study are as follows. First, the small group inquiry skills gave a significant influence on increasing the science process skills, including the basic science process skills and the integrated science process skills, of students. Especially, among subordinate factors of science process skills between groups, it was effective to increase abilities of observing, reasoning, interpreting data, formulating hypothesis. It is necessary for teachers to make an effort to teach according to steps of the small group inquiry skills and to support inquiry activities, in order to increasing the science process skills. However, frequency of additional lessons have a little influence on increasing the science process skills. Second, there is meaningful change in the attitudes toward science for those who studied the small group inquiry skills. Also, they affected subordinate factors of the attitudes toward science, like the attitudes toward science inquiry, the happiness about science class. This study shows that the small group inquiry skills give a positive influence on the science process skills and attitudes toward science in elementary school science.

• Journal of the Korean Society of Earth Science Education
• /
• v.5 no.2
• /
• pp.197-203
• /
• 2012

The main purpose of this research is to search the effect of different types of advance organizers in elementary science classes, to the students in acquiring scientific concepts and its retentions. In order to proceed with the research, We have chosen 93 students of three different classes of fifth graders, studying in M elementary school in U metropolitan city. We have randomly chosen two classes as an experimental group and one class as a comparative group. In the first experimental group (Group1), advance organizer was put in a form of a sentence., and the second experimental group (Group2), advance organizer was put in a form of a picture. For the comparative group, We have not put any advance organizer, and the method of class was proceeded as it was before. The result of this research are as follows. Firstly, the result of 'One-way analysis of variance' on scientific concept grade, right after the experiment on three groups, has shown a meaningful difference that, the shape of advance organizer does affect the acquisition of elementary school students' scientific concept. Secondly, even though Group1, who was given with a sentence as an advance organizer, got higher scientific concept scores after the experiment than that of comparative group, However, there was not a meaningful difference between Group1 and comparative group. Thirdly, Group2, who was given with a picture as an advance organizer, has shown a meaningful difference from comparative group. Judging from the facts above, utilizing an advance organizer of a picture in elementary science class, will be very affective on students' acquiring scientific concept.

• Hwankyungkyoyuk
• /
• v.21 no.1
• /
• pp.16-30
• /
• 2008

This study was aimed at finding what effects pro-con discussion classes have on students' environmental decisions and set a series of research questions as follows. First, in a small group discussion, how a student's environmental decision is affected by opinions of other students in the same group. Second, what would be the relations between a students' personal factors including gender, environmental knowledge, attitude, and behavior and their decisions. A decisional experiment was applied to 185 students consisting of 2 girl classes and 4 boy classes of K highschool located in Kongju City, Chungnam. These students were taking 'Ecology and Environment' as one of the few general selective subjects once a week. Decision issue introduced to the experiment was regarding of constructing a wind power station on Baekdu Mountains which is protected by the law. This issue can be characterized as not conflict between conservation and development but conflict between two different types of environment friendly approaches that make students experience more difficult while making a decision. The results of this study an be summarized as follows. First, after taking the class introducing environmental issues and having a debate other students on the issue both within a small group or all classmates together, just less then 30% of the students changed their selections. Second, students were found to be affected by other students' opinion while making his or her own decision. Third, no relationship was found to be statistically considerable between students decisions and their personal factors except of their courses, liberal or science.

• Journal of The Korean Association For Science Education
• /
• v.16 no.4
• /
• pp.451-460
• /
• 1996

The ethical issue is one of the most important themes in both science and environmental education. Especially related to the right of other species, animal dissection has been brought about two contradictory attitudes. In spring 1996, a survey was conducted to assess the status of animal dissection in secondary schools and the awareness of 94 biology teachers and 422 secondary students toward animal dissection. And the meaning of animal dissection in biology class was discussed in terms of environmental education. The findings were as follows: First, most of students(96.6%) had participated once or twice to animal dissection experiments(eg. fish, frog, shellfish, cuttlefish and chicken). And about half of teachers (57.4$\sim$64.9%) and some students(41.9%) felt ethical conflict in animal dissection. Second, many teachers(81.0%) and students(87.1%) thought that animal dissection was effective method to achieve the goal of biology education, but they needed more consideration on the respect for life in animal dissection experiment. Third, many teachers(88.3%) had students, who objected to animal dissection, participate obligatorily or passively. Fourth, teachers and students thought that audio-visual media such as video(teachers 63.5%, students 39.7%), computer simulations(teachers 31.7%, students 28.1%) and models(teachers 22.2%, students 24.1%) could be effective as alternatives. These findings suggest that animal dissection experiment, although it is needed to achieve the goal of biology education, requires careful consideration on the rights of animal and the respect for life, and alternatives for students who object to animal dissection in biology class.

• Women's Health Nursing
• /
• v.8 no.3
• /
• pp.345-357
• /
• 2002

The purpose of this study is to find out how the Father Class, which is being practiced at a hospital located in Seoul, influences on fathers' level of knowledge and confidence of postpartal mother and newborn care. Research design was quasi-experimental study using non equivalent experiment and control group. The data, questionaires, were collected from Sep. 13, 2001 to Oct. 31, 2001 through e-mail, telephone and mail, after discharge from S hospital located in Seoul, where the experimental group was educated at the Father Class and control group didn't take part in the class. The objects were the fathers who have the first baby through normal delivery or C-sec delivery including experimental group 48 persons and control group 52 persons. Four instruments were the revised ones of Lee Mi Kyoung's(1990) and Kwak Yon Hee's tool based on the resources of direct interviews of fathers and one expert, professor. The reliability of four instruments were Cronbach's $\alpha$ scores .85 -93. Data were analyzed by SPSS 10.0 program using $x^2$-test, and t-test and, One- way ANOVA, and Pearson correlation, etc. The results of this study are as follows; 1.The two groups were confirmed as a homogeneous group by showing no significant difference statistically at the level of 5%. 2.The results of proving the hypothesis are followings: 1)The first hypothesis, "the fathers who participated in the Father Class will have the higher level of knowledge about postpartal mother care than the fathers who didn't" was accepted by significant difference statistically (p=0.000). 2)The second hypothesis, "the fathers who took part in the class will have the higher confidence in postpartal mother care than the fathers who didn't", was supported by significant difference statistically (p=0.000). 3) The third hypothesis, "the fathers who attended the class will have the better knowledge about taking care of newborn than the others", was accepted by significant difference statistically (p=0.000). 4)The fourth hypothesis, "the fathers who participated in the class will have the higher confidence in newborn care than others," was supported by significant difference statistically (p=0.000). 3.The further analysis showed whether they participated in Prenatal Birth Preparing Class influenced on the father's level of knowledge and confidence in postpartal mother and newborn care. In conclusion, the Father Class is the effective nursing intervention strategy that can help new fathers attain father and husband roles by enhancing the level of confidence in and knowledge of the postpartal mother and newborn care.