• Title/Summary/Keyword: Research Topics

Search Result 2,273, Processing Time 0.025 seconds

Study on the procedure to obtain an attainable speed in pack ice

  • Kim, Hyun Soo;Jeong, Seong-Yeob;Woo, Sun-Hong;Han, Donghwa
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.10 no.4
    • /
    • pp.491-498
    • /
    • 2018
  • The cost evaluation for voyage route planning in an ice-covered sea is one of the major topics among ship owners. Information of the ice properties, such as ice type, concentration of ice, ice thickness, strength of ice, and speed-power relation under ice conditions are important for determining the optimal route in ice and low operational cost perspective. To determine achievable speed at any designated pack ice condition, a model test of resistance, self-propulsion, and overload test in ice and ice-free water were carried out in a KRISO ice tank and towing tank. The available net thrust for ice and an estimation of the ice resistance under any pack ice condition were also performed by I-RES. The in-house code called 'I-RES', which is an ice resistance estimation tool that applies an empirical formula, was modified for the pack ice module in this study. Careful observations of underwater videos of the ice model test made it possible to understand the physical phenomena of underneath of the hull bottom surface and determine the coverage of buoyancy. The clearing resistance of ice can be calculated by subtracting the buoyance and open water resistance form the pre-sawn ice resistance. The model test results in pack ice were compared with the calculation results to obtain a correlation factor among the pack ice resistance, ice concentration, and ship speed. The resulting correlation factors were applied to the calculation results to determine the pack ice resistance under any pack ice condition. The pack ice resistance under the arbitrary pack ice condition could be estimated because software I-RES could control all the ice properties. The available net thrust in ice, which is the over thrust that overcomes the pack ice resistance, will change the speed of a ship according to the bollard pull test results and thruster characteristics (engine & propulsion combination). The attainable speed at a certain ice concentration of pack ice was determined using the interpolation method. This paper reports a procedure to determine the attainable speed in pack ice and the sample calculation using the Araon vessel was performed to confirm the entire process. A more detailed description of the determination of the attainable speed is described. The attainable speed in 1.0 m, 90% pack ice and 540 kPa strength was 13.3 knots.

A Global XQuery Query Processing based on Local XQuery Query Generation (지역 질의 생성기반 전역 XQuery 질의 처리 기법)

  • Park, Jong-Hyun;Park, Won-Ik;Kim, Young-Kuk;Kang, Ji-Hoon
    • Journal of the Korea Society of Computer and Information
    • /
    • v.15 no.11
    • /
    • pp.11-20
    • /
    • 2010
  • XML view is proposed to integrate between XML data and heterogeneous data over distributed environment and global XML view is used to search distributed heterogeneous data. At this time, standard query language for user is XQuery and the method for processing global XQuery queries over distributed environment is one of the new research topics. One of the basic and simple methods to process distributed SQL queries is that generates local queries for processing a global query and constructs the result of the global query from the results of the local queries. However, the syntax of XQuery differs from SQL because the XQuery contains some special expressions like FOR clauses for querying to semi-structured data, of course, FOR clauses are not used in SQL. Therefore, there are some problems to adopt the method for processing global SQL queries for generating local XQuery queries. This paper defines some problems when generates local XQuery queries for processing global XQuery queries and proposes a method for generating local XQuery queries considered these problems. Also we implement and evaluate a Global XQuery Processor which uses our method.

The effects of SSI Argumentation Program on the Preservice Biology Teachers' Decision-Making Types and Communication Ability (과학기술과 관련된 사회적 쟁점에 대한 논증 프로그램이 예비 생물교사들의 의사결정 유형과 의사소통 능력에 미치는 영향)

  • Kim, Sun Young
    • Journal of Science Education
    • /
    • v.42 no.1
    • /
    • pp.12-26
    • /
    • 2018
  • This study examined the effects of SSI argumentation program on the preservice biology teachers' decision-making types and communication ability. The SSI argumentation program was developed based on 'Social Decision-Making & Problem-Solving strategy' and Toulmin's argumentation pattern. The preservice teachers had opportunities of SSI argumentation through small group discussions. They were asked to identify the issues regarding SSI, think of solutions, and make a decision along with claims, warrants, data, and rebuttals. The preservice biology teachers experienced four SSI topics of abortion, euthanasia, gene manipulation, artificial intelligence. The results indicated that the preservice biology teachers significantly improved the communication ability after the intervention, but they did not change their types of decision-making. In addition, after the intervention, the Pearson correlation results indicated that 'the logical type' of decision-making significantly relates to the communication ability(p<.01). The preservice biology teachers mentioned that they improved their ability of considering warrants, data, background information, context, and rebuttals. Further, the preserivce biology teachers mentioned that they became take an interest in socioscientific issues and improved their ability of accepting criticism from others as well as caring about others when they argue each other. This study implicated that the SSI argumentation program has effects on improving personality education in school science.

A Preliminary Study on Designing PDS Model for Korean Mathematics Teachers (한국형 수학교사 전문성 개발 체제(PDS) 모델 구축을 위한 기초 연구)

  • Lee, Kyeong Hwa;Na, Gwi Soo;Kwon, Na Young;Kim, Dongwon;Lee, Hwan Chul;Lee, Dong Hwan;Ko, Eun Sung;Park, Min Sun;Park, Mimi;Lee, Eun Jung;Cho, Jin Woo;Park, Jin Hyeong
    • Journal of Educational Research in Mathematics
    • /
    • v.22 no.4
    • /
    • pp.581-602
    • /
    • 2012
  • For developing mathematics teachers' professionalism, it is necessary to construct PDS to provide training programs which are appropriate for Korean context and needed by mathematics teachers. This study is a preliminary study for constructing PDS and aims to design PDS model for Korean mathematics teachers. Firstly, components of model were elicited by theoretical review. Secondary, focus group discussion with 8 teachers and individual interview with 1 educational profession and 3 foreign mathematics education researchers were conducted. Finally, by reflecting FGD and interview results, the final version of PDS model was designed. The final model is constructed by 3 components, which are life cycle, program types, and participants. In addition, professional development topics for each life cycle according to PDS model are presented.

  • PDF

A Study on the Classification of Student's Bluffing on Geographical Terms (지리 용어에 대한 학습자의 블러핑(Bluffing) 유형에 관한 연구)

  • Jang, Eui-Sun
    • Journal of the Korean Geographical Society
    • /
    • v.49 no.4
    • /
    • pp.615-632
    • /
    • 2014
  • This study aims to explore 'bluffing', one of the most important topics in order to ensure the objectivity, validity, reliability of scoring of constructed-response items. The author identifies the conception of bluffing, and classifies major types of bluffing on the basis of previous studies on the theoretical level. Next, the author analyzes empirically the bluffing strategies and types of learners on key terms of Korean Geography subject. Compared with the existing research reports, the result of this study shows a significantly lower average bluffing score. On the other hand, it is consistent in results of previous studies reported that average bluffing score is similar between genders and that those students who got highest grades did least bluffing. Actually bluffing types are classified into four categories: 'repeating the question' type, 'depending on a well-known or existing knowledge' type, 'applying some basic concepts regardless of understanding' type, and 'inducing scorer's basic beliefs' type. Some comments and suggestions are as follows. First, it is necessary to continue researches of the relations among bluffing and age, gender, grade, intelligence and learning styles. Second, it is required for scorers who score constructed-response items to develop and supply the scoring guide including analysis contents of bluffing types and cases, and increase opportunity for training. Third, we need to inquire the domain-specific bluffing types in geography subject based on the generalizable sample size.

  • PDF

The Components of Portfolio Assessment for Korean Elementary Science Classroom (초등학교 자연과 포트폴리오 평가(Portfolio Assessment)의 구성 요소)

  • Kim, Chan-Jong;Kim, Hye-Jeong
    • Journal of The Korean Association For Science Education
    • /
    • v.18 no.2
    • /
    • pp.233-243
    • /
    • 1998
  • Many science educators concern about the problems of assessment using paper & pencil test. Performance assessment is believed to be a very promising alternatives to traditional assessment. Portfolio assessment, a kind of performance assessment, has many desirable characteristics to foster students' creativity and increase students' responsibility for their own learning. However few research study has been dealt with this assessment method and few teacher adopts this method in science class. The characteristics and structures of portfolio assessment were explored by reviewing related literatures. The appropriate portfolio assessment was designed based on the results of exploration. For our primary science class, general and specific objectives are needed, depending on the nature of the instructional topics. The children's evidences for portfolio may be limited in their forms because of insufficient learning materials and reproducing facilities in classrooms. Large portions of children's evidence should be collected during class hours to reduce burdens of children. The evaluation criteria may be holistic rather than analytical because of large class size. Portfolio assessment will bring about many changes in primary science classes. Students' have more responsibility in science learning. Teachers will focus major instructional objectives, and concern more about students' meaningful learning. Although portfolio assessment requires more work to teachers and children it could be applicable to our science classroom.

  • PDF

The Cases of Integrated Science Education Practices in Schools -What are the ways to facilitate integrated science education?- (통합 과학교육을 실천하고 있는 두 중등학교의 사례 -무엇이 통합 과학교육을 가능하게 하는가?-)

  • Ahn, Jungyong;Na, Jiyeon;Song, Jinwoong
    • Journal of The Korean Association For Science Education
    • /
    • v.33 no.4
    • /
    • pp.763-777
    • /
    • 2013
  • This is a case study on two schools practising integrated science education (hereafter ISE). The purposes of this study are to investigate the types and features of ISE in the schools actively practising ISE, to identify the contextual factors of the schools, and to give implications for implementing ISE in schools. This study investigated the contextual factors in practicing ISE with a focus on the two schools, a middle school in Gyeonggi-do and a high school in Busan. They were breaking down the boundaries among teaching subjects and providing student-oriented instruction with problems in the real world. The data were collected by observing classes, by interviewing teachers, and by reviewing school documents and students' reports. The research findings are as follows: first, the two schools took part in ISE actively. They teach science to students providing integrated experiences mainly by using interdisciplinary knowledge and/or by solving the problems pertaining to the real world. While the former integrated subjects centering on topics, the latter focused on a project-based learning driven by students. They have differences in regard to the role of teachers and students, the level of integration and the type of integration. Second, the contextual factors that enabled ISE to be implemented there were found. The previous studies revealed six contextual factors in practising ISE: small and stable learning environment, leadership, team activities, in-school planning time, flexible timetable and community links. This study also found similar factors. However, the cases of this study provided ISE on a large scale and in a short period of time, instead of a small and stable learning environment. Teachers viewed the process of ISE not only as a tool to overcome the conservative culture of teachers but also as a pursuit of innovation.

A Study on the Cultural Exchange of the Weaving Skills and Patterns Witnessed in Geum-textiles between the East and West - from Ancient Times to the Tang Dynasty - (제직기술과 문양을 통해 본 금직물(錦織物)의 동서교류에 관한 연구 - 고대부터 당시대를 중심으로 -)

  • Shin, Hey-Sung
    • Journal of the Korean Society of Costume
    • /
    • v.62 no.4
    • /
    • pp.107-122
    • /
    • 2012
  • The purpose of this study is to investigate the changes and developments that occurred as a result of the exchanges of gyeong-geum(經錦), a warp-faced compound weave of East Asia, and wie-geum(緯錦), a weft-faced compound weave of West Asia. In order to maximize the efficiency of this research, topics were narrowed down to the weaving skills and patterns, and the period was limited to the Tang dynasty. The systematic characteristics and differences of gyeong-geum and wie-geum were compared and contrasted through different works of literature. Then the excavated remains of geum-textiles were analyzed and the characteristics of the geum-textiles were defined in chronological order. The origin of wie-geum is traced back to the time when West Asia started to imitate the weaving style of the East Asian gyeong-geum. When combined with the weaving skills of the West Asian, gyeong-geum, which broke through the West and developed into the weft-faced compound twill silk, or samite. The exchange of geum-textiles took place as the techniques of gastric filament woven geum-textiles returned to the East. Along with the pearl roundel motifs of Sassanian Persia, mythical animals and western motifs of hunter patterns were used for the patterns of wie-geumin during the early Tang dynasty. This tendency is related to pa-sa-geum(波斯錦), ho-geum(胡錦), beon-geum(番錦) according to the recorded literature. The 8th and 9th century are periods when the West Asian Persian style was abandoned and the East Asian style, samite, was established. Not only did S twist silk threads replace Z twists, but also the repetition of patterns unfolded along with the weft and the warp. As this tendency was strengthened after the 9th century, the expression of patterns became more vividly colorful and showed both elements of naturalism and realism. The characteristics of the Bosangwha(寶相花) pattern in the Tang period were established with the rampantly repeated rosettes with birds often holding auspicious branches, that fly amid floral compositions.

A Study on the Development of Book Talk Shows Program Applied Talk, Music, and Video Shows (토크.뮤직.영상 쇼의 개념을 적용한 북 토크 쇼 개발 연구)

  • Lee, Jong-Moon
    • Journal of Korean Library and Information Science Society
    • /
    • v.39 no.1
    • /
    • pp.279-297
    • /
    • 2008
  • The purpose of this research is to perform reading based on their levels of reading readiness for different groups of readers, to develop the Book Talk Show program which was dependent on the philosophies and emotions on reconstructed topics of the concerned books by Talk, Music, and Video Shows, enabled communal sharing of the effects of reading, to provide an evaluation tool of such applications in real readings, and to evaluate the validity and usefulness of the devised program scheme. At first, the concept of "Book Talk Shows" was established on the base of the definition of Talk, Music, and Video Shows, then the program was applied to the readers across 4 different Book Talk Shows, and examined its problems and any possible revisions. At the same time, the survey was conducted on 39 experts and professional in the field of Book Talk Show management[31 people(79.5%) provided answers to the survey) on the validity and usefulness of the devised program scheme. The Results of survey showed that 27 people(87.1% of the people who provided answers to the survey) said that these suggestions were "very valuable and useful" and 24 people from this group(88.9%) said that they would like to "apply" such program designs to their own programs. However, the vast majority of the recipients said that they would face problems of 'budget' and 'readiness' when applying such program design, and emphasized the importance of budget assurance in developing and applying future models in Book Talks Show programs.

  • PDF

Measuring the Professional Development Needs for Technical and Vocational Education and Training Staff in Nepal: A Look at Teachers' Perceptions (네팔 직업기술교육훈련 교사들의 교육훈련 프로그램 요구조사)

  • Lim, Jin Ho;Kim, Dongwook
    • Journal of Practical Engineering Education
    • /
    • v.12 no.1
    • /
    • pp.163-176
    • /
    • 2020
  • Promoting job growth and quality has been central to developing countries to reduce poverty for decades. In this regard, Nepal is not unique in its need to develop effective TVET programme as it is considered showing positive association with workforce development and productivity. While the copious academic literature has highlighted upon staff training programme in general education, it encounters lack of adequate attention in the field of TVET education. The purpose of the study is to identity and prioritise the professional development needs for the teachers of TVET sector in Nepal. A sample(N=317) of Nepalese teachers from seven provinces were asked to answer the scale. The Borich needs assessment model was employed to assess the perceived level of importance and present preferred training modules among 29 teaching subjects. Moreover, a quadrant analysis using 2×2 matrix was used as a diagnostic tool to denote overriding training topics. The result shows that following competence skills constructs were perceived to be in high need of enhancement as well as in existence of discrepancies: 'occupational characteristics of TVET trainer', 'training needs analysis and curriculum development', 'curriculum development based on national competence standard(NCS)', and 'Institution management evaluation'.