• Journal of Biomedical Engineering Research
• /
• v.21 no.2
• /
• pp.119-127
• /
• 2000

금속판/형과스크린 계측기와 CCD 카메라를 이용한 방사선영상장치가 현재 전자포탈영상에 널리 쓰이고 있다. 이 장치의 효율적인 영상획득을 위해 계측효율이 좋고, 공간분해능력이 뛰어난 금속판/ 형과스크린 계측기의 두께를 최적화할 필요가 있었다. 이 논문에서는 금속판과 형광스크린의 두께가 계측효율과 공간분해능에 미치는 영향이 연구되었다. 이 결과는 치료 엑스선 영상장치에 쓰일 수 있는 금속판/형과스크린 계측기의 최적화된 두께를 결정하는데 쓰일 수 있다. 몬테칼로 방법을 이용하여 계산한6 MV 선형가속기에서 발생되는 엑시선의 에너지 스펙트럼을 바탕으로, 여러 가지 두께의 금속판/형광스크린에 대하여 계측효율과 공간분해능을 계산하였고, 이를 실험을 통해 검증하였다. 계측효율은 입사된 엑스선의 에너지가 형광스크린에 흡수된 비율로 계산되며, 공간분해능은 흡수된 에너지의 공간 분포를 통해 계산되었다. 계측효율은 금속판의 두께에 의해, 공간분해능은 형광스크린의 두께에 의해 결정될 수 있음을 본 연구를 통해 확인할 수 있었고, 이로써 특정이용에 관련된 금속판/형광스크린의 두께에 대한 서로 보상 (trade-off) 관계에 있음을 계산과 측정결과를 통해 확인할 수 있었고, 이로써 특정이용에 관련된 금속판/형광스크린 계측기의 최적화된 두께를 산출할 수 있게 되었다. 계산을 바탕으로 CCD를 이용한 전자포탈영상장치의 시작품을 설계 및 제작하였고 팬텀을 이용하여 영상을 얻었다. 단일 프레임 영상은 노이즈가 많으나, 프레임 평균 방법을 이용하여 영상의 질을 향상시킬 수 있었다.

• Journal of Korea Water Resources Association
• /
• v.39 no.7 s.168
• /
• pp.617-626
• /
• 2006

In this study 3-month SPI data from 59 stations over the Korean peninsula are analyzed by deriving and spatially characterizing the EOFs. Also, the coefficient time series of EOF are applied to the multi-variate time series model to generate the time series of 10,000 years, to average them to estimate the areal average, and to decide the maximum drought severity for given return periods. Finally, the drought prevention ability is evaluated by considering the effective storage of dam within the basin and the size of agricultural area. Especially for the return period of 30 years, only the Han river basin has the potential to overcome the drought. Other river basins like the Youngsan river basin, which has a large portion of agricultural area but less water storage, are found to be very vulnerable to the rainfall-sensitive agricultural drought.

• Journal of Korean Association for Spatial Structures
• /
• v.7 no.6
• /
• pp.61-68
• /
• 2007

The hole for the insertion of the pin in the shank is exist at ball joint connection of the space frame. It brings about the brittle fracture caused by stress concentration. Consequently it cannot expect the deformation performance or energy absorption performance from ball joint connection. In this study we developed a new connection details which will increase the plastic deformation performance at ball joint connection and can absorb the error in construction, which expect the plastic deformation performance at the reduced shank without brittle fracture at the screw of bolt and pin. Also it's capacity is verified by the performance in numerical analysis and test. We confirmed bolt's plastic deformantion performance through controled shank and pin's area.

• 대한공업교육학회지
• /
• v.44 no.2
• /
• pp.1-27
• /
• 2019

In recent years, space planning ability using 3D sketch software is required in the working field of interior design. However, vocational high school do not respond appropriately to changes in the industry, because the class of vocational high school consists of hands-on practical classes and 2D CAD based classes. There is a shortage of 3D sketch software-based instruction programs that can improve students' spatial planning skills. Therefore, this study is to develop instruction program using 3D sketch software for 'Planning for Residential Space' unit of NCS-based on interior design subject and to find out the effect on students' academic achievement by applying to vocational high school class. The 3d sketch software based instructional program developed in this study was developed through four stages of preparation, development, implementation and evaluation according to the PDIE model process. The experimental design model used nonequivalent group posttest-only design in this study. Experiments were conducted on vocational high school students in construction and 9 hours of interior design subjects were applied. After the experiments, students were tested for academic achievement in the cognitive, affective, and psychomotor areas. As a result, the instruction program using the 3d sketch program developed in this study was found to be more effective in improving students' academic achievement than existing manual instruction program in both cognitive, affective, and psychomotor areas.

• Fire Science and Engineering
• /
• v.30 no.1
• /
• pp.121-129
• /
• 2016

Ambulances are an important element of pre-hospital emergency medical services, and also an important space for improving the work efficiency of paramedics. Paramedics use the interior environment to maximize the capabilities of the space, but ambulances need to be improved to help with the responsibilities of paramedics. A Seamless space was constructed in accordance with the placement of first-aid emergency medical equipment and drugs, and a patient room was loaded in the interior space of an ambulance. This study was to improve the treatment space of an ambulance to improve the efficiency of work by paramedics The new design provides safety and efficiency for emergency medical services through planning of interior storage suitable for the duties of paramedics and through identification and analysis of the problems in the environment.

• The KIPS Transactions:PartD
• /
• v.18D no.6
• /
• pp.451-460
• /
• 2011

The ability to trace change history and dependency relations of software artifacts which are continuously changed has been recognized as an important factor that support quality management activities such as verification, validation, and testing in software system development process. General software configuration management systems provide tracing information for artifacts only within the configuration management system, and it does not go further to changes that occur within personal workspace. This paper provides a solution that helps tracing down not only changes of configuration items but also change history of artifacts existent in personal workspace through the integration of configuration management system and personal workspace. Furthermore, in cases of artifacts which are included in a configuration item, this paper provides a solution that support tracing dependency relations between the artifacts by identifying their version links. For the integration of configuration management system and personal workspace, a revision of configuration item is connected to the artifact's version of the workspace by the tagging mechanism, and traceability for change history and dependency relations of artifacts can be managed more effectively through integrated change process.

• Journal of the Korea Computer Graphics Society
• /
• v.4 no.1
• /
• pp.89-100
• /
• 1998

A multi-user virtual reality system supports shared environments for concurrent accesses by multiple users. The performance of these systems depends heavily on the network environments. This paper experiments an effective network model for shared virtual environments. This model has a middle layer called groups placed between the server and its clients, and the tasks of server are distributed to these groups. Using groups solves some of the problems of existing systems such as lack of scalability, message overheads, and latency due to message passing among locally communicating entities in the virtual environment. Some experiments show lower overhead than existing distributed virtual environment systems in WAN as well as LAN environments. This model also supports a method that can be used to construct application specific network environments using message handler which allows user-defined message formats.

• School Mathematics
• /
• v.14 no.1
• /
• pp.1-28
• /
• 2012

The purpose of the study are to identify factors of mathematical visualization through the thirty students of highschool 2nd year and to investigate how each visualization factor is used in mathematics problem solving process. Specially, this study performed the qualitative case study in terms of the five of thirty students to obtain the high grade in visuality assessment. As a result of the analysis, visualization factors were categorized into mental images, external representation, transformation or operation of images, and spacial visualization abilities. Also, external representation, transformation or operation of images, and spacial visualization abilities were subdivided more specifically.

• Journal of Gifted/Talented Education
• /
• v.20 no.1
• /
• pp.1-30
• /
• 2010

The purpose of this study was to develop the inspection model of cognitive ability to identify visual artistic giftedness of the elementary school children with considering the relation between visual artistic giftedness and cognitive ability based on literature and preceding research. The research method applied literature research and quantitative research. Through literature review on the relation between art education and cognitive thinking and visual artistic of giftedness, it was suggested to prescribe the validity of cognitive ability as an element for identification of visual artistic giftedness identification, and then prescribed the elements of cognitive ability, and developed the inspection model of cognitive ability by measuring specific variables. Based on the results of literature research through the quantitative research, verified significance of developed inspection instrument on cognitive ability, validity and reliability of the inspection model of cognitive ability according to visual artistic giftedness identification of the elementary school children. As a result of reviewing related literature and preceding research, it could be referred that visual thinking ability, spatial perception power and critical thinking ability coincided with a characteristic of an art field can show excellent ability in various art activities and be valid criteria of visual artistic giftedness as cognitive ability of the visual artistic gifted with potential possibilities. In conclusion, as the elements of cognitive ability for the visual artistic giftedness identification of the elementary school children, visual thinking ability, spatial perception power and critical thinking ability were verified to be valid in terms of logical and experimental. Therefore, the result of the research will be able to provide a new approach in education program development of visual artistic giftedness of the elementary school children and a various developmental possibility in identification of visual artistic giftedness.

• Journal of Gifted/Talented Education
• /
• v.16 no.2
• /
• pp.167-191
• /
• 2006

The purpose of this study was to explore logical thinking abilities and metacognitive characteristics by student's giftedness and grade level. Furthermore, this study sought to present the practical basis for the promotion of students' abilities in self-driven learning as well as cognition. Average-ability students(n=199), economically disadvantage gifted students(n=133), and gifted students(n=111), who were sampled by two-step sampling procedures, responded the logical thinking ability test(Cho et al, 2006) and the questionnaire asking self-perception for 'metacognitive knowledge' and 'metacognitive control' abilities(Cho & Han, 2004). As the results, average-ability students showed less logical thinking abilities(in language, mathematics, and space) than gifted students. The logical thinking abilities had affected by giftedness, grade level and these interaction. And gifted students showed higher metacognitive control abilities in planning, monitoring, priority, and strategies of learning than average-ability students. However, there were no significant differences in metacognitive knowledge and metacognitive control abilities between economically disadvantaged gifted students and gifted students.