• Journal of Forest and Environmental Science
• /
• 제30권1호
• /
• pp.101-106
• /
• 2014

The purpose of this research was to figure out the stand structure and growth characteristic with relation to DBH, height, and volume in sixteen Pinus koraiensis plantations of Gangwon province region. Age class was diversely distributed from age class II (16 yr) to age class VIII (77 yr), and, in terms of site index, sixteen regions were superior: nine regions 'high', seven regions 'middle'. The distribution of DBH by sites appeared a bell-shaped curve, and the number of trees was the most in diameter section of 18-22 cm. The dispersion of DBH was various with age and widest ranging from 18 cm to 58 cm in age class VII-VIII. The distribution of height was also a bell-shaped curve with the smaller deviation than the distribution of DBH, and most of trees were in height section of 14-18 m. The correlation of DBH and height was high (r=0.75), and the volume bigger than 1.0 $m^3$ was presented from DBH 35 cm, height 20 m.

• International Journal of Computer Science & Network Security
• /
• 제21권6호
• /
• pp.127-136
• /
• 2021

In the systems and software modeling field, a conceptual model involves modeling with concepts to support development and design. An example of a conceptual model is a description developed using the Unified Modeling Language (UML). UML uses a model multiplicity formulation approach, wherein a number of models are used to represent alternative views. By contrast, a model singularity approach uses only a single integrated model. Each of these styles of modeling has its strengths and weaknesses. This paper introduces a partial solution to the issue of multiplicity vs. singularity in modeling by adopting UML use cases and class models into the conceptual thinging machine (TM) model. To apply use cases, we adopt the observation that a use-case diagram is a description that shows the internal structure of the part of the system represented by the use case in addition to being useful to people outside of the system. Additionally, the UML class diagram is recast in TM representation. Accordingly, we develop a TMUML model that embraces the TM specification of the UML class diagram and the internal structure extracted from the UML use case. TMUML modeling introduces some of the advantages that have made UML a popular modeling language to TM modeling. At the same time, this approach supplies UML with partial model singularity. The paper details experimentation with TMUML using examples from the literature. Our results indicate that mixing UML with other models could be a viable approach.

• 한국전자파학회논문지
• /
• 제22권12호
• /
• pp.1060-1068
• /
• 2011

본 논문에서는 900 MHz 대역에서 동작하는 전류 모드 Class-D(Current-Mode Class-D: CMCD) 전력 증폭기를 설계 및 제작하고 특성을 분석하였다. 차동 구조에 의해 짝수차 고조파 성분이 제거된다는 점에 착안하여 출력단의 일반적인 CMCD 회로의 병렬 공진기를 제거하고 inverse class-F 전력 증폭기를 push-pull 구조로 연결하여 CMCD 전력 증폭기를 설계하였다. 로드-풀 기법을 이용하여 GaN 소자 기반의 inverse class-F 및 이를 적용한 CMCD 전력 증폭기를 설계 및 제작하였다. 제작한 CMCD는 34.2 dBm의 출력과 64.5 %의 드레인 효율을 가지며, 이는 출력측에 공진기 구조를 가지는 일반적인 CMCD 전력 증폭기의 드레인 효율과 비교했을 때 13.6 %의 효율 향상을 가진다.

• 한국초등과학교육학회지:초등과학교육
• /
• 제39권1호
• /
• pp.133-144
• /
• 2020

The purpose of this study is to identify the effect of Teacher Participation-oriented Education Program (TPEP) for Elementary School Teachers to Improve Class Expertise in Science Classes with a focus on visual attention. The participants were two elementary school teachers in Seoul and taught science subjects. The lesson topic applied to this study were 'Structure and Function of Our Body' in the second semester of fifth grade and 'Volcano and Earthquake' in the second semester of fourth grade. The mobile eye tracker SMI's ETG 2w, which is a binocular tracking system was used in this study. In this study, the actual practice time, participant's visual attention, visual intake time average, and visual intake time average were analyzed by class phase. The results of the study are as follows. First, as a result of analyzing the actual class execution time, the actual class execution time was almost in line with the lesson plan after the TPEP application. Second, visual attention in the areas related to teaching and learning activities was high after applying TPEP. Factors affecting the progress of the class and cognitive burdens were identified quantitatively and objectively through visual attention. Third, as a result of analyzing the visual intake time average of participants, there was a statistically significant difference in all classes. Fourth, as a result of analyzing the visual intake time average of participants, the results were statistically significant in the introduction(video), activity 1, activity 2, and activity 3 stages in the lecture type class. The Teacher Participation-oriented Education Program (TPEP) for Elementary School Teachers to Improve Class Expertise in Science Classes can extend elementary science class expertise such as self-class analysis, eye tracking, linguistic, gesture, and class design beyond traditional class analysis and consulting.

• 아동학회지
• /
• 제37권2호
• /
• pp.13-25
• /
• 2016

Objective: The purposes of this study were to examine the effects of school-age children's ego strength, failure tolerance, and performance anxiety on their school class adjustment, and to model the relation structure of the variables. Method: For these purposes, a questionnaire survey was conducted with 562 6th graders. Results and Conclusion: The results of this study are summarized as follows. First, ego strength, failure tolerance, and performance anxiety were significantly different according to gender. Second, in male students, ego strength, failure tolerance, and performance anxiety had a significant direct effect on school class adjustment. In addition, ego strength and failure tolerance had a significant indirect effect on school class adjustment. Third, female students' paths to school class adjustment were similar to male students' but the effect of failure tolerance on performance anxiety and the effect of performance anxiety on school class adjustment were not significant. Fourth, in the results of multi-group analysis, the effect path from ego strength to school class adjustment was different between male and female students, and the effect was higher in female students than in male students.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 C
• /
• 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.

• 한국컴퓨터정보학회논문지
• /
• 제22권1호
• /
• pp.153-159
• /
• 2017

In recent years there has been a rise in the use and interest of the flipped learning as a teaching and learning paradigm. The flipped learning model includes any use of Internet technology to enrich the learning in a classroom, so that a professor can spend more time interacting with students instead of lecturing. In the flipped model, students viewed video lectures online outside of class time. Students then performed two kinds of assignments, a teamwork assignment and an individual work assignment, through the class time. In this paper, we propose a flipped educational model for a college class. This experimental research compares class of college algorithm using the flipped classroom methods and the traditional lecture-homework structure and its effect on student achievement. The result data of mid-term exam and final exam were analyzed and compared with previous year data. The findings of this research show that there was not a significant difference in the scores of student between two lecturing methods. The survey result and lecture evaluation by students show that students are in favor of the flipped learning.

• 대한가정학회지
• /
• 제38권12호
• /
• pp.1-14
• /
• 2000

The purpose of this study is to identify the change according to income bracket and the trade-off between expenditure items by analyzing expenditure patterns of the urban households as a reset of the IMF. The results of this study are as follows; The composition percentage and the amount of consumption expenditure of urban households after IMF decrease in all classes. But the change of composition percentage by the decrease of consumption expenditure is different in every class. The percentage of decrease of the upper class is higher than that of the lower class in an essential expenditure of household, which is food. And the percentage of decrease of the lower class is higher than that of the higher class in the discretionary expenditures such as clothes and education.

• 천문학회보
• /
• 제41권2호
• /
• pp.54.3-55
• /
• 2016

We model the spectral energy distribution (SED) of the Class 0 protostar L1527 IRS using a dust continuum radiative transfer code RADMC-3D to study the initial condition of gravitational collapse. To constrain the envelope structure, we use the data obtained by Herschel /PACS, which covers the far-infrared regime ($55-190{\mu}m$) where the SED of L1527 IRS peaks. According to our modeling, a more flattened density profile fits the far-infrared SED of L1527 IRS better than the density profile of a rotating and infalling envelope. Thus, we employ the density structure of a Bonnor-Ebert sphere, which consists of the inner flat-topped and the outer power-law regions and is often used for describing the density structure of the youngest sources in the low mass star formation process. A Bonnor-Ebert sphere fits very well the observed SED at ${\lambda}$ > $10{\mu}m$, suggesting that L1527 IRS might collapse from an unstable Bonnor-Ebert sphere rather than a singular isothermal sphere.

• Bulletin of the Korean Chemical Society
• /
• 제26권1호
• /
• pp.85-90
• /
• 2005

MX and its analogs are synthesized and modeled by quantitative structure activity relationship (QSAR) study including comparative molecular field analysis (CoMFA). As a result, factors affecting this class of compounds have been found to be steric and electrostatic effects. Because hologram quantitative structure activity relationship (HQSAR) technique is based on the 2-dimensional descriptors, this is free of ambiguity of conformational selection and molecular alignment. In this study we tried to include all the data available from the literature, and modeled with the HQSAR technique. Among the parameters affecting fragmentation, connectivity was the most important one for the whole compounds, giving good statistics. Considering additional parameters such as bond specification only slightly improved the model. Therefore connectivity has been found to be the most appropriate to explain the mutagenicity for this class of compounds.