• Title/Summary/Keyword: Physics

Search Result 14,510, Processing Time 0.058 seconds

Measurement uncertainty analysis of radiophotoluminescent glass dosimeter reader system based on GD-352M for estimation of protection quantity

  • Kim, Jae Seok;Park, Byeong Ryong;Yoo, Jaeryong;Ha, Wi-Ho;Jang, Seongjae;Jang, Won Il;Cho, Gyu Seok;Kim, Hyun;Chang, Insu;Kim, Yong Kyun
    • Nuclear Engineering and Technology
    • /
    • v.54 no.2
    • /
    • pp.479-485
    • /
    • 2022
  • At the Korea Institute of Radiological and Medical Sciences, physical human phantoms were developed to evaluate various radiation protection quantities, based on the mesh-type reference computational phantoms of the International Commission on Radiological Protection. The physical human phantoms were fabricated such that a radiophotoluminescent glass dosimeter (RPLGD) with a Tin filter, namely GD-352M, could be inserted into them. A Tin filter is used to eliminate the overestimated signals in low-energy photons below 100 keV. The measurement uncertainty of the RPLGD reader system based on GD-352M should be analyzed for obtaining reliable protection quantities before using it for practical applications. Generally, the measurement uncertainty of RPLGD systems without Tin filters is analyzed for quality assurance of radiotherapy units using a high-energy photon beam. However, in this study, the measurement uncertainty of GD-352M was analyzed for evaluating the protection quantities. The measurement uncertainty factors in the RPLGD include the reference irradiation, regression curve, reproducibility, uniformity, energy dependence, and angular dependence, as described by the International Organization for Standardization (ISO). These factors were calculated using the Guide to the Expression of Uncertainty in Measurement method, applying ISO/ASTM standards 51261(2013), 51707(2015), and SS-ISO 22127(2019). The measurement uncertainties of the RPLGD reader system with a coverage factor of k = 2 were calculated to be 9.26% from 0.005 to 1 Gy and 8.16% from 1 to 10 Gy. A blind test was conducted to validate the RPLGD reader system, which demonstrated that the readout doses included blind doses of 0.1, 1, 2, and 5 Gy. Overall, the En values were considered satisfactory.

Operating Budget Management Plan on Electric Energy Consumption of Educational Facilities (교육시설물의 전기에너지 사용량에 따른 운영예산 관리방안)

  • Wang, Ji-Hwan;Jin, Chengquan;Lee, Sanghoon;Hyun, Chang-Taek
    • Korean Journal of Construction Engineering and Management
    • /
    • v.23 no.4
    • /
    • pp.26-35
    • /
    • 2022
  • The 7th education reform in 1997 has led changes in the way buildings were constructed and such changes drove educational facilities to steadily consume more energy every year. Also, these facilities take several years' estimated expenditure as well as the increased unit price of electricity into account when planning their annual operating budget. Such circumstances may adversely affect the establishment of their budget plan since improper allocation of operating costs could take place. To propose educational facilities' operating budget management plan on electrical energy consumption, this study developed a model that help oversee the facilities' consumption of electrical energy. For the model development, the primary core variables related to electrical energy factors from the aspects of surroundings, physics, policy, etc. were derived from taking both literature research and the characteristics of these facilities into account. The secondary core variables were then derived using the correlation analysis. Lastly, the electric energy use prediction model was developed by performing regression analysis based on the derived secondary core variables.

Development of Tutorial for Measuring Gravity Acceleration Using Arduino and Its Educational Application (아두이노를 활용한 중력 가속도 측정과 관련된 튜토리얼 및 교육적 활용 방안)

  • Kim, Hyung-Uk;Mun, Seong-Yun
    • The Journal of the Korea Contents Association
    • /
    • v.22 no.6
    • /
    • pp.69-77
    • /
    • 2022
  • Physical experiment through MBL has been used in many schools for a long time since students can check the experiment results immediately and conduct the experiment easily. However, conducting the experiment, not knowing the principle of the device or simply concentrating on the derived data has been raised as the problem of MBL experiment. To supplement this problem, this study measured the acceleration of gravity with the picket fence method, which is often used in MBL experiment, utilizing Arduino, calculated the error rate through a comparison to the actual acceleration of gravity and discussed the educational application of the experiment to measure it. As a result of the experiment, the error rate between the acceleration of gravity calculated by the experiment and the actual acceleration of gravity was about 1%, so it turned out that relatively accurate measurements were possible. Also, the sample mean of the experimental value was included in the confidence interval of 95%, so it could be concluded that it was a significant experiment. In addition, this study showed the possibility of the educational application of the experiment to measure it through the following: It can supplement the structural disadvantages of MBL; it can consider the interaction between Physics and Math; it is possible to converge with information course in STEAM education; and it is inexpensive to be equipped with the equipment. Hopefully, the physical experiment utilizing Arduino will further be revitalized in science gifted education based on this study.

Ultrasonic methods for measuring the cortical bone thickness in bovine tibia in vitro (생체 외 조건의 소 경골에서 초음파를 이용하여 피질골 두께를 측정하기 위한 방법)

  • Lee, Kang Il
    • The Journal of the Acoustical Society of Korea
    • /
    • v.41 no.5
    • /
    • pp.557-563
    • /
    • 2022
  • The cortical bone thickness of the tibia is related to fracture risk and overall bone status. The present study aims to investigate the feasibility of two different ultrasonic methods for measuring the cortical bone thickness in bovine tibia in vitro. In the reflection technique, the tibial cortical thickness was determined from ultrasonic reflections from the periosteum and the endosteum producing specific peaks in the signal envelope. In the axial transmission technique, the tibial cortical thickness was determined from ultrasonic guided wave velocities measured along the axial direction of the tibia. The cortical bone thickness determined by using the reflection technique correlated significantly with that measured by using a caliper, with a Pearson's correlation coefficient of r = 0.97 (p < 0.0001). In contrast, the correlation coefficients for the axial transmission technique were r = 0.92 (p < 0.0001) for the first arriving signal method and r = 0.89 (p < 0.0001) for the slow guided wave method. Clinical feasibility should be demonstrated with an in vivo application to address the question whether the ultrasonic methods presented here could be useful as a screening tool for osteoporosis and potentially could be applied to other skeletal sites such as the femur and the radius.

On the "Virtual and Real" and Blankness in Chinese Landscape Painting

  • Dongqi, Liu
    • International Journal of Advanced Culture Technology
    • /
    • v.10 no.3
    • /
    • pp.174-183
    • /
    • 2022
  • The abstract should summarize the contents of the paper and written below the author information. Use the word "Abstract" as the title, in 12-point Times New Roman, boldface type, italicized, centered relative to the column, initially capitalized, fixed-spacing at 13 pt., 12 pt. spacing before the text and 6 pt. after. The abstract content is to be in 11-point, italicized, single spaced type. Leave one blank line after the abstract, and then begin the keywords. All manuscripts must be in English. When it comes to the issue of "virtual and real" in traditional Chinese painting, the first impression is to describe the problems of painting strokes and ink, layout of pictures, etc., but it runs through the initial conception of the work, creation in the middle and aesthetic appreciation of the work. It exists in the whole process of artistic creation and appreciation. In essence, it is a problem of aesthetic thinking and philosophical thinking. Because the traditional Chinese painting theory is influenced by Taoism, when the concept of "virtual and real" is implemented in the specific picture of Chinese painting, it is contained in the specific shape of "physics", that is, the painting theory research of "blank space" in the picture. Based on the traditional Taoist philosophy of China, this paper takes the "virtual and real" view in Lao Zhuang's thought as the research object, deeply analyzes and compares its relationship with the "virtual and real" in Chinese landscape painting, and finds out their artistic spirit, essential characteristics and how to present them. This paper mainly discusses the internal relationship between Taoist philosophy and "virtual and real" in Chinese landscape painting from the following aspects. The introduction expounds the origin, purpose, significance, innovation and research methods of the topic. This paper analyzes the philosophical thoughts about landscape in the philosophical thoughts represented by Lao Tzu and Zhuangzi. The development of Chinese traditional aesthetics theory is closely related to Taoist philosophy, which has laid the foundation and pointed out the direction for the development of Chinese painting theory since ancient times. It also discusses the influence of the Taoist philosophy of "the combination of the virtual and real" on the emergence and development of the artistic conception of landscape painting. Firstly, through the analysis of the artistic conception of landscape painting and its constituent factors, it is pointed out that the artistic conception is affected by the personality and the painting artistic conception. Secondly, through the Taoist thought of "the combination of the virtual and real" in landscape painting, so as to reflect that it is the source of the artistic conception of Chinese landscape painting. It is the unique spiritual concept of "Yin and Yang" and "virtual and real" that creates the unique "blank space" aesthetic realm of Chinese painting in the composition of the picture. Finally, it focuses on the "nothingness" in Taoist philosophy and the "blank space" in Chinese landscape painting. The connotation of the "blank space" in Chinese painting exceeds its own expressive significance, which makes the picture form the aesthetic principle of emotional blending, virtual and real combination and dynamic and static integration. Through the "blank space", it deepens the artistic characteristics of the picture and sublimates the expression of "form" in Chinese painting.

The Analysis of the Effect of Understanding and Practices of Character-centered Instruction Model on Pre-service Science Teachers' Awareness of Character Education (인성 중심 교수 모형에 대한 이해와 실천이 예비 중등 과학교사의 인성 교육에 대한 인식에 미치는 영향 분석)

  • Park, Jihun;Kang, Eugene;Nam, Jeonghee
    • Journal of the Korean Chemical Society
    • /
    • v.65 no.4
    • /
    • pp.279-295
    • /
    • 2021
  • The purpose of this study was to investigate the effect of Character-centered instruction model on pre-service science teachers' awareness of both character education and character education in science education. First of all, pre-questionnaires about the sixteen pre-service science teachers' awareness of character education and character education in science education were asked. Through the lectures during a semester, they received an education about CoProC(Collaborative Problem-Solving for Character competence) model using Character-centered instruction model and character education. After the implementation, their changes of awareness were inspected through post-questionnaires. As a result of the study, it was revealed that general pre-service science teachers' pre-awareness of character education was mostly negative. The pre-service science teachers were more aware of character education in science classes than general character education. Even that, there seemed to be a greater tendency to think in connection with specific content and subject matter and character education rather than developing competencies due to the nature of the science subject itself. However, the experiences of the CoProC model changed their perception about character into a competent point of view, and thus influenced the change in their perception of character education. Therefore, education on character education methods for pre-service science teachers at teacher training institutions will increase their expertise in character education and help establish effective character education in school in the long term.

A Study on Implications and Improvement Plans for the Developing Consultation Guidelines for Environmental Assessment of Offshore Wind Power Development Projects (해상풍력 개발사업의 환경성 평가 협의 지침 개발에 관한 시사점 및 개선안 연구)

  • Haemi, Lee;Junho, Maeng
    • Journal of Environmental Impact Assessment
    • /
    • v.31 no.6
    • /
    • pp.449-464
    • /
    • 2022
  • This study reviewed the development process of the consultation guideline for the environmental assessment of offshore wind power. Based on this, implications and improvement plans for a future revision of the guidelines. Domestic and foreign case studies reviewed the consulting cases on domestic offshore wind power development projects, environmental location consulting cases, and guidelines related to overseas offshore wind power and analyzed location characteristics and significant environmental issues by project. Major environmental issues related to offshore wind power include birds, noise and vibration, marine animals and plants, marine physics, marine water quality and sediments, marine landscapes, and other auxiliary facilities installed on land. Implications and improvements for revising the consultation guidelines for evaluating offshore wind environments require data and clear guidelines at the central government level to determine areas where offshore wind projects can be located. In a situation where the importance of cumulative impact assessment is emphasized, guidelines for cumulative impact assessment methodologies for each item that reflect the domestic situation should be prepared for a cumulative impact assessment on offshore wind power environmental issues. In addition, when revising the consultation guidelines, empirical research cases should be reflected through the accumulation of environmental surveys and monitoring data of offshore wind farms by sea area.

Implications for Teacher Education through Pre-Service Science Teachers' Perception and Practice Cases on Online Formative Assessment (온라인 형성평가에 대한 예비 과학교사의 인식과 실행 사례를 통해 살펴본 교사 교육의 시사점)

  • Hyojoon, Kim;Jinwoong, Song
    • Journal of The Korean Association For Science Education
    • /
    • v.42 no.5
    • /
    • pp.501-514
    • /
    • 2022
  • This study aims to reveal what is necessary for pre-service science teachers to make good use of online formative assessment in the context of online classes. For 22 pre-service physics teachers, first, the preliminary perception of online classes, online formative assessment, and formative assessment was investigated; second, the practice process of online formative assessment was examined. Then the differences between perception and practice were compared and analyzed. Data were collected in preliminary surveys, lesson plans, online formative assessment items, and interview data. As a result of the study, an interaction was mentioned as the difficulty of online classes in the preliminary perception, and pre-service teachers mentioned the use of technology, feedback, and adjustment as advantages of online formative assessment. In most cases of practice, the automated feedback was used using the platform's technology, but it did not lead to adjustment and interaction. In addition, the use of items in online formative assessment was not suitable for formative functions. The reason why the interaction using formative feedback did not occur seems to be because the understanding of formative assessment was insufficient. Pre-service teachers need to be prepared for the 'formative' function through the feedback of online formative assessment so that can lead to interaction in online classes. The shift to online classes is creating difficulties, especially in interaction. It is necessary to prepare and educate pre-service teachers on fundamental aspects that can overcome these difficulties.

Comparison of Internal and External Frameworks for Units on Magnets in Elementary Science Textbooks First Developed by the Authorization System (검정제에 의해 최초 개발된 초등과학교과서들의 자석 단원에 대한 내외적 체제 비교)

  • Seongsoo, Jeon
    • Journal of The Korean Association For Science Education
    • /
    • v.42 no.5
    • /
    • pp.525-542
    • /
    • 2022
  • The purpose of this study is to comparatively analyze the internal and external frameworks of elementary science textbooks, which first appeared as the authorization system of elementary science textbooks changed from the national government system. In order to confirm the purpose of the authorization system to support the development of diverse and creative textbooks, this study compared 7 authorized textbooks with the national textbook developed as the 'Use of Magnets' unit of the 2015 revised science curriculum. In this study, the textbook's framework was largely divided into an external framework and an internal framework for the 'Use of Magnets' unit of elementary science textbooks, and quantitative and qualitative analyses were conducted in parallel according to each subcategory. According to the research results, in the external framework of textbook units, all textbooks had the same structure: unit introduction, scientific inquiry, creative convergence, unit arrangement, and scientific reading materials. The framework in the 'Use of Magnets' unit of the 7 types of authorized textbooks was found to have some differences according to the textbook development team's interpretation of the curriculum achievement standards and many commonalities that maintained the framework in the national textbooks. In addition, the characteristics of each textbook were clearly revealed in some areas not specified in curriculum such as unit introduction activities and science reading materials, a meaningful change was also found in that the level of inquiry activity was classified and operated in response to the uniform inquiry activity operation of the existing government textbooks.

A Comparative Study of Branching Ratio of 167Yb Radioactive Isotope from Gamma-ray Spectrum Produced by 169Tm(p,3n)167Yb Reaction with 100-MeV Proton Beam (100-MeV 양성자 빔을 이용하여 169Tm(p,3n)167Yb 반응에 의해 생성된 167Yb 방사성동위원소에서 방출되는 감마선 스펙트럼 비교 연구)

  • Sam-Yol, Lee
    • Journal of the Korean Society of Radiology
    • /
    • v.16 no.7
    • /
    • pp.953-960
    • /
    • 2022
  • The measurement of branching ratio of 167Yb radioactive isotopes from gamma-ray spectrum of 169Tm(p,3n)167Yb reaction were performed by using a 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC). The 167Yb isotope has a half-life of 17.5 minutes and decays to 169Tm. The gamma rays generated from the 167Yb isotope were measured using an HPGe detector gamma ray spectroscopy system. The energy calibration of the detector and the efficiency measurement of the detector were determined using a standard source. The gamma rays of known main energy (62.9, 106.2, 113.3, 143.5 and 176.3 keV) were measured. On the other hand, information about the intensity of the generated gamma rays is very inaccurate. Therefore, in this study, the decay strength of the main gamma rays was accurately measured. Overall, it was different from the previously known results, and in particular, it was found that the intensity of the main decay gamma ray, such as the 113.3 and 106.2 keV gamma ray, was overestimated, and it was found that the gamma ray, such as 62.9, 116.7 and 143.5 keV was underestimated. The present results are considered to be important information in the fields of nuclear fusion, astrophysics and nuclear physics in the future.