We investigate ow and magnetic structure of a solar prominence with a focus on how the magnetic eld originally determined by subsurface dynamics gives rise to the structure. We perform a magnetohydrodynamic simulation that reproduces the self-consistent evolution of a ow and the magnetic eld passing freely through the solar surface. By analyzing Lagrangian displacements of magnetized plasma elements, we demonstrate the ow structure that is naturally incorporated to the magnetic structure of the prominence formed via dynamic interaction between the ow and the magnetic eld. Our results explain a diverging ow on a U-loop, a counterclockwise downdraft along a rotating eld line, acceleration and deceleration of a down ow along an S-loop, and partial emergence of a W-loop, which may play key roles in determining structural properties of the prominence.

In this study, we developed a learning progression for the structure of the solar system using multi-tier supply form items and validated its appropriateness. To this end, by applying Wilson’s (2005) construct modeling approach, we set up ‘solar system components,’ ‘size and distance pattern of solar system planets,’ and ‘solar system modeling’ as the progress variables of the learning progression and constructed multi-tier supply form items for each of these variables. The items were applied to 150 fifth graders before and after the classes that dealt with the ‘solar system and star’ unit. To describe the results of the assessment, the students’ responses to each item were categorized into five levels. By analyzing the Wright map that was created by applying the partial credit Rasch model, we validated the appropriateness of the learning progression based on the students’ responses. In addition, the validity of the hypothetical pathway that was established in the learning progression was verified by tracking changes in the developmental level of students before and after the classes. The results of the research are as follows. The bottom-up research method that used multi-tier supply form items was able to elaborately set the empirical learning progression for the conceptualization of the structure of the solar system that is taught in elementary school. In addition, the validity of the learning progression was high, and the development of students was found to change with the learning progression.

본 연구에서는 SOI 구조를 이용한 50μm 두계의 규소 태양전지의 이용 가능성과 제한사항을 제시하기 위하여, interdigitated contact을 이용한 전극을 형성하도록 전지를 설계한 후 단계별 사진공정을 통해 태양전지를 제조하였다. Bonded SOI wafer를 이용하여 제조된 50μm 두께의 결정질 규소 태양전지의 효율은 전극간격이 1100μm과 base width가 35μm인 경우에서 11.5%로 가장 높은 값을 나타내었다. 또한 실험결과로부터 전면전극을 이용한 태양전지의 구조는 power loss를 최소화하는 최적의 base fraction을 적용하는 것이 필요하며, 전지의 효율은 fill factor에 강한 의존성을 나타내기 때문에 fill factor loss를 최소화하는 설계조건이 필요함을 알 수 있었다.

Recently, the rotational solar tracker system is presented for the high electric efficiency. The horizontal rotation tracker is the structure for rotationg horizontally the most important part. However, it is difficult to secure the safety and maintenance in solar tracker systems. Therefore, this study suggests the reasonable structure type for horizontal rotational solar tracker through the strength reinforcement of the structure to ensure stability.

Solar tracker structure is usually installed outdoor. Therefore, the structure can be influenced by wind load and snow load. In this study, the safety evaluation is performed by analyzing the results according to structural modelling and analysis for solar tracker structure. Also, solar tracker structure module is presented under the various design variables.

Recently, the manually adjustable solar structures are reguired for the angle variation of solar module to increase the electric power efficiency. Therefore, this study presents the adjustable connections in support structure and estimates the stiffness of the connections for the structural performance evaluation of the manually adjustable solar structure