• Title/Summary/Keyword: Self-energy

Search Result 1,844, Processing Time 0.029 seconds

Negative apparent resistivity in dipole-dipole electrical surveys (쌍극자-쌍극자 전기비저항 탐사에서 나타나는 음의 겉보기 비저항)

  • Jung, Hyun-Key;Min, Dong-Joo;Lee, Hyo-Sun;Oh, Seok-Hoon;Chung, Ho-Joon
    • Geophysics and Geophysical Exploration
    • /
    • v.12 no.1
    • /
    • pp.33-40
    • /
    • 2009
  • In field surveys using the dipole-dipole electrical resistivity method, we often encounter negative apparent resistivity. The term 'negative apparent resistivity' refers to apparent resistivity values with the opposite sign to surrounding data in a pseudosection. Because these negative apparent resistivity values have been regarded as measurement errors, we have discarded the negative apparent resistivity data. Some people have even used negative apparent resistivity data in an inversion process, by taking absolute values of the data. Our field experiments lead us to believe that the main cause for negative apparent resistivity is neither measurement errors nor the influence of self potentials. Furthermore, we also believe that it is not caused by the effects of induced polarization. One possible cause for negative apparent resistivity is the subsurface geological structure. In this study, we provide some numerical examples showing that negative apparent resistivity can arise from geological structures. In numerical examples, we simulate field data using a 3D numerical modelling algorithm, and then extract 2D sections. Our numerical experiments demonstrate that the negative apparent resistivity can be caused by geological structures modelled by U-shaped and crescent-shaped conductive models. Negative apparent resistivity usually occurs when potentials increase with distance from the current electrodes. By plotting the voltage-electrode position curves, we could confirm that when the voltage curves intersect each other, negative apparent resistivity appears. These numerical examples suggest that when we observe negative apparent resistivity in field surveys, we should consider the possibility that the negative apparent resistivity has been caused by geological structure.

Comparison of Experimental and Radiation Therapy Planning (RTP) Dose Distributions on Air Cavity (공동(air cavity)의 존재 시 실험적 선량분포와 치료계획상의 선량분포 비교)

  • Kim, Yon-Lae;Suh, Tae-Suk;Ko, Shin-Gwan;Lee, Jeong-Woo
    • Journal of radiological science and technology
    • /
    • v.33 no.3
    • /
    • pp.261-268
    • /
    • 2010
  • This study is compared that the dose distribution by experimentation and radiation therapy planning (RTP) when the air cavity region was treated high energy photon. The dose measurements were performed with a 6 MV photon beam of linear accelerator. The polystyrene and self made acyl phantom were similar to tissue density of the human body. A parallel plate chamber was connected to an electrometer. The measurement setup was SCD (Source Chamber Distance) 100 cm and the distance of surface from air cavity was 3 cm. Absorbed dose of interface were measured by area and height. The percent depth dose were measured presence and absence of air cavity, depth according to a ratio of field size and air cavity size. The dose distribution on planning was expressed to do the inhomogeneity correction. As the area of air cavity was increased, the absorbed dose were gradually reduced. It was slightly increased, when the height of air cavity was changed from 0 cm to 0.5 cm. After the point, dose was decreased. In case of presence of air cavity, dose after distal air cavity interface was more great than absence of air cavity. The rebuild up by field size and area of air cavity occurred for field size, $4{\times}4\;cm^2$, $5{\times}5\;cm^2$ and $6{\times}6\;cm^2$, with fixed on area of air cavity, $5{\times}5\;cm^2$. But it didn't occur at $10{\times}10\;cm^2$ field size. On the contrary, the field size was fixed on $5{\times}5\;cm^2$, rebuild up occurred in area of air cavity, $4{\times}4\;cm^2$, $5{\times}5\;cm^2$. but, it did not occur for air cavity, $2{\times}2\;cm^2$, $3{\times}3\;cm^2$. All of the radiation therapy planning were not occurred rebuild up. It was required to pay attention to treat tumor in air cavity because the dose distribution of planning was different from the dose distribution of patient.

Perfluoropolymer Membranes of Tetrafluoroethylene and 2,2,4Trifluofo- 5Trifluorometoxy- 1,3Dioxole.

  • Arcella, V.;Colaianna, P.;Brinati, G.;Gordano, A.;Clarizia, G.;Tocci, E.;Drioli, E.
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • 1999.07a
    • /
    • pp.39-42
    • /
    • 1999
  • Perfluoropolymers represent the ultimate resistance to hostile chemical environments and high service temperature, attributed to the presence of fluorine in the polymer backbone, i.e. to the high bond energy of C-F and C-C bonds of fluorocarbons. Copolymers of Tetrafluoroethylene (TEE) and 2, 2, 4Trifluoro-5Trifluorometoxy- 1, 3Dioxole (TTD), commercially known as HYFLON AD, are amorphous perfluoropolymers with glass transition temperature (Tg)higher than room temperature, showing a thermal decomposition temperature exceeding 40$0^{\circ}C$. These polymer systems are highly soluble in fluorinated solvents, with low solution viscosities. This property allows the preparation of self-supported and composite membranes with desired membrane thickness. Symmetric and asymmetric perfluoropolymer membranes, made with HYFLON AD, have been prepared and evaluated. Porous and not porous symmetric membranes have been obtained by solvent evaporation with various processing conditions. Asymmetric membranes have been prepared by th wet phase inversion method. Measure of contact angle to distilled water have been carried out. Figure 1 compares experimental results with those of other commercial membranes. Contact angles of about 120$^{\circ}$for our amorphous perfluoropolymer membranes demonstrate that they posses a high hydrophobic character. Measure of contact angles to hexandecane have been also carried out to evaluate the organophobic character. Rsults are reported in Figure 2. The observed strong organophobicity leads to excellent fouling resistance and inertness. Porous membranes with pore size between 30 and 80 nanometers have shown no permeation to water at pressures as high as 10 bars. However high permeation to gases, such as O2, N2 and CO2, and no selectivities were observed. Considering the porous structure of the membrane, this behavior was expected. In consideration of the above properties, possible useful uses in th field of gas- liquid separations are envisaged for these membranes. A particularly promising application is in the field of membrane contactors, equipments in which membranes are used to improve mass transfer coefficients in respect to traditional extraction and absorption processes. Gas permeation properties have been evaluated for asymmetric membranes and composite symmetric ones. Experimental permselectivity values, obtained at different pressure differences, to various single gases are reported in Tab. 1, 2 and 3. Experimental data have been compared with literature data obtained with membranes made with different amorphous perfluoropolymer systems, such as copolymers of Perfluoro2, 2dimethyl dioxole (PDD) and Tetrafluorethylene, commercialized by the Du Pont Company with the trade name of Teflon AF. An interesting linear relationship between permeability and the glass transition temperature of the polymer constituting the membrane has been observed. Results are descussed in terms of polymer chain structure, which affects the presence of voids at molecular scale and their size distribution. Molecular Dyanmics studies are in progress in order to support the understanding of these results. A modified Theodoru- Suter method provided by the Amorphous Cell module of InsightII/Discover was used to determine the chain packing. A completely amorphous polymer box of about 3.5 nm was considered. Last but not least the use of amorphous perfluoropolymer membranes appears to be ideal when separation processes have to be performed in hostile environments, i.e. high temperatures and aggressive non-aqueous media, such as chemicals and solvents. In these cases Hyflon AD membranes can exploit the outstanding resistance of perfluoropolymers.

  • PDF

Human Thermal Sensation and Comfort of Beach Areas in Summer - Woljeong-ri Beach, Gujwa-eup, Jeju-si, Jeju Special Self-Governing Province - (여름철 해변지역의 인간 열환경지수 및 열쾌적성 - 제주특별자치도 제주시 구좌읍 월정리 해변 -)

  • Park, Sookuk;Sin, Jihwan;Jo, Sangman;Hyun, Cheolji;Kang, Hoon
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.44 no.4
    • /
    • pp.100-108
    • /
    • 2016
  • The climatic index for tourism(CIT) has recently been advanced, which includes complete human energy balance models such as physiological equivalent temperature(PET) and universal thermal climate index(UTCI). This study investigated human thermal sensation and comfort at Woljung-ri Beach, Jeju, Republic of Korea, in spring and summer 2015 for landscape planning and design in beach areas. Microclimatic data measurements and human thermal sensation/comfort surveys from ISO 10551 were conducted together. There were 869 adults that participated. As a result, perceptual and thermal preference that consider only physiological aspects had high coefficients of determination($r^2$) with PET in linear regression analyses: 92.8% and 87.6%, respectively. However, affective evaluation, personal acceptability and personal tolerance, which consider both physiological and psychological aspects, had low $r^2s$: 60.0%, 21.1% and 46.4%, respectively. However, the correlations between them and PET were all significant at the 0.01 level. The neutral PET range in perceptual for human thermal sensation was $25{\sim}27^{\circ}C$, but a PET range less or equal to 20% dissatisfaction, which was recommended by ASHRAE Standard 55, could not be achieved in perceptual. Only PET ranges in affective evaluation and personal tolerance affected by both aspects were qualified for the recommendation as $21{\sim}32^{\circ}C$ and $17{\sim}37^{\circ}C$, respectively. Therefore, the PET range of $21{\sim}32^{\circ}C$ is recommended to be used for the human thermal comfort zone of beach areas in landscape planning and design as well as tourism and recreational planning. PET heat stress level ranges on the beach were $2{\sim}5^{\circ}C$ higher than those in inland urban areas of the Republic of Korea. Also, they were similar to high results of tropical areas such as Taiwan and Nigeria, and higher than those of western and middle Europe and Tel Aviv, Israel.

A Study on the Correlation Analysis of EEG and Vibraimage due to Auditory and Olfactory Stimulation (청각 및 후각자극에 의한 뇌파(EEG)와 진동이미지기술의 상관성 분석에 관한 연구)

  • Kim, Jung-Min;Kim, Myung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.6
    • /
    • pp.4291-4297
    • /
    • 2015
  • EEG has been used to measure the emotion of amenity and discomfort in the interior space. EEG is limited to the experiment, because it is a equipment of contact type. However, Vibraimage can measure the emotion with a web camera. Because Vibraimage is a equipment of non-contact type, it is more suitable for the interior space than EEG. Therefor, it tries to find a correlation variable between EEG and Vibraimage to measure the human emotions. In this study, it were analyzed correlation of EEG and vibraimage due to variation of loudness 60[dB], 90[dB] and rosemary, jasmine scents. Check the health status of subjects who were selected 3 male students, and the period of this experiment was about months. The condition of the environmental test room was in temperature 25[$^{\circ}C$], relative humidity 50[RH%], air current speed 0.02[m/s] and illuminance 1000[lux]. It were analyzed correlation of twenty-three index of EEG(absolute ${\theta}$, relative ${\theta}$, absolute $S{\alpha}$, relative $S{\alpha}$, absolute ${\alpha}$, relative ${\alpha}$, absolute ${\beta}$, relative ${\beta}$, absolute $\gamma$, relative $\gamma$, absolute $F{\alpha}$, relative $F{\alpha}$, absolute SMR, relative SMR, $SMR/{\theta}$, $SMR+M{\beta}/{\theta}$, absolute $H{\beta}$, relative $H{\beta}$, $H{\beta}/{\alpha}$, absolute $M{\beta}$, relative $M{\beta}$, SEF50, ASEF50) and ten index of Vibraimage(Aggression, Stress, Tension/Anxiety, Suspect, Balance, Charm, Energy, Self regulation, Inhibition, Neuroticism). As a result, I was found that relative ${\gamma}$ index of EEG and neuroticism index of Vibraimage have a high correlation as (${\pm}$).414 and (${\pm}$).424.

A Comparative Study of Dietary Behaviors and Nutrient Intakes According to Alcohol Drinking among Male University Students in Chungnam (충남지역 일부 남자 대학생의 알코올 섭취수준에 따른 식행동 및 영양섭취상태 비교 연구)

  • 최미경;전예숙;김애정
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.30 no.5
    • /
    • pp.978-985
    • /
    • 2001
  • The purpose of this study was to investigate the effect of alcohol drinking on dietary behaviors and nutrient intakes among the university male students. The subjects were divided three group; no-alcohol group(n=83), alcohol group(n=78), and high-alcohol group(n=78).And they were observed general characteristics, life style, eating pattern, food frequency and nutrient intake using questionnaires. The mean age, height, weight and BMI of the subjects were 25.8$\pm$6.1 years old 171.5$\pm$5.4 cm, 63.4$\pm$9.7 kg and 2.3$\pm$2.8/kg/$m^2$, respectively. The types of residence and person who prepares meals were significantly different among the groups: the frequency of self-boarding and preparing meals oneself in high-alcohol group were higher than in other two groups. The frequency of physical exercise and cigarette smoking in high-alcohol group were higher than in other two groups. There were no significant differences in skipping meals among three groups. However, the most common reson why high-alcohol group skipped meals was due to a eating habit, while a lack of time in other two groups. The results show that the high-alcohol group tended to eat more often instant ramien, soybean sprout, anchovy, and coffee compared to the other two groups. The energy intakes in alcohol and high-alcohol groups were lower than those in no-alcohol group. In conclusion, high-alcohol students have unhealthy dietary behaviors in the light of high frequency of cigarette smoking, eating habit of skipping meals and instant foods, and therefore showing a strong need of proper education in alcohol withdrawal and meal management for them.

  • PDF

A Study on the aesthetic of Calligraphy by Seok Jeon Hwang Wook (석전(石田) 황욱(黃旭)의 서예미학(書藝美學) 고찰)

  • Kim, Doyoung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.8 no.2
    • /
    • pp.227-234
    • /
    • 2022
  • Seok Jeon Hwang Wook (18913~1999), a descendant of a traditional literary writer in the western part of Honam, did not join the flow of modern and contemporary calligraphy and painting. And throughout his life, he enjoyed himself without losing the appearance of a scholar, immersed himself in traditional calligraphy, and gained spotlight at his late age for his original hand grabbing calligraphy. Immediately after the Korean War, all of his property was lost due to his two sons' left-wing activities, causing great pain at home. Even in the most painful and difficult time in human history, he relied on brushes, poetry, and gayageum to keep his upright scholarly spirit and national love. And beyond the pleasures of the worldly senses, he played with self-satisfaction in the 'true pleasure(大樂)' without greed. In the course of his studies, he focused on honing the fonts of Wang Hui-ji, Gu Yang-sun, An Jin-gyeong, Jo Maeng-bu, and Xin-wi and Lee Sam-man without a special teacher. In particular, he faced a crisis of having to give up his brush due to tremor that came after his 60th birthday, but he showed a strong will. He transformed it into a new style of art, such as developing hand grabbing calligraphy(握筆法) with a strong and strong energy that no one could match. From 1965 to 1983, 'right hand grabbing calligraphy' was used, and from 1984 to 1993, 'left hand grabbing calligraphy' was used. She made her name as a calligrapher widely known in 1973 (age 76) with her first solo exhibition, The Calligraphy Exhibition commemorating her 60th wedding anniversary. His writing method is naturally rough and sloppy by breaking away from the previous calligraphy methods and artificial technique, and is unfamiliar yet full of muscle. And the calm, strong and rough chuhoegsa(錐劃沙) and the heavy yet majestic ininni(印印泥) individual handwriting expressed a strange feeling and achieved original Seokjeon calligraphy that went beyond the existing calligraphy writing methods, and his indomitable calligraphy spirit was As a unique existence in the history of calligraphy, he still remains as a model.

Blended IT/STEM Education for Students in Developing Countries: Experiences in Tanzania (개발도상국 학생들을 위한 블랜디드 IT/STEM교육: 탄자니아에서의 경험 및 시사점)

  • Yoon Rhee, Ji-Young;Ayo, Heriel;Rhee, Herb S.
    • Journal of Appropriate Technology
    • /
    • v.6 no.2
    • /
    • pp.151-162
    • /
    • 2020
  • Education is one of the priority sectors specified in Tanzania, and it has committed to provide 11 years of compulsory free basic education for all from pre-primary to lower secondary level. Despite the Government's efforts to provide free basic education to all children, there are 2.0 million (23.2 per cent) out of 8.5 million children at the primary school age of 7-13, who are out of school in Tanzania. The ICT class should be offered as a regular class in all secondary schools in Tanzania, recommended by the ministry of education. However, many schools are struggling to implement this mandate. Most of schools offer the ICT class with theory without any real hardware. Some schools were given with computers but they were not maintained for operation. There is a huge task to make ICT education universal. Main issues include: remoteness (off-grid area), lack of ICT teachers, lack of resources such as hardware, infrastructure, and lack of practical lessons or projects to be used at schools. An innovative blended ICT/STEM education program is being conducted not only for Tanzanian public and private/international schools, but also for out-of-school adolescents through institutions, NGO centers, home visits and at the E3 Empower academy center. For effective STEM education to take place and remain sustainable, more practical curriculum, and close-up teacher support need to be accompanied concurrently. Practical, project-based simple coding lessons have been developed and employed that students experience true learning. The effectiveness of the curriculum has been demonstrated in various project centers, and it showed that students are showing new interests in exploring new discovery, even though this was a totally new area for them. It has been designed for an easy replication, thus students who learned can repeat the lessons themselves to other students. The ultimate purpose of this project is to have IT education offered as universally as possible throughout the whole Tanzania. Quality education for all children is a key for better future for all. Previously it was hoped that education with discipline will improve the active learning. But now more than ever, we believe that children have the ability to learn on their own with given proper STEM education tools, guidelines and environment. This gives promising hope to all of us, including those in the developing countries.

Application and effectiveness of a nutrition education program based on the 2020 Dietary Reference Intakes for Koreans for undergraduates in Gyeongsangnam-do and Gyeonggi-do (2020 한국인 영양소 섭취기준 활용 자료를 이용한 영양교육 프로그램의 적용 및 효과: 경상남도 및 경기도 지역 대학생을 대상으로)

  • Mijoo Choi;Hyein Jung;Nayoung Kim;Sangah Shin;Taejung Woo;Eunju Park
    • Journal of Nutrition and Health
    • /
    • v.56 no.6
    • /
    • pp.730-741
    • /
    • 2023
  • Purpose: The 2020 Dietary Reference Intakes for Koreans (KDRIs) serves as a foundation for daily nutrient and energy recommendations aiming to enhance public health and prevent chronic diseases. They act as guidelines for maintaining proper nutrition and overall health. Using KDRIs is crucial for promoting healthier lifestyles and making informed dietary choices. Thus, this study explores the influence of a nutrition education program, based on the 2020 KDRIs, on the nutrition knowledge and dietary habits of undergraduates in Gyeongsangnam-do and Gyeonggi-do. Methods: The nutrition education program, designed with diverse instructional materials, was executed across a wide range of universities. The education group (n = 75) engaged in the program for a 6-week instructional period, while the control group (n = 53) underwent the survey without participating in the education program. Nutrition Quotient (NQ) and knowledge assessments were administered to both groups immediately before and after the instructional period. Results: Within the education group, the nutrition education program positively impacted responses to NQ practice items, including knowledge of nutrition, daily intake, and portion sizes (p < 0.05). In contrast, there were no significant differences between the before and after responses of the control group for most survey items. Post-program evaluations showed significantly higher self-assessment scores and increased satisfaction levels (p < 0.05), with the satisfaction rate for the education program using the 2020 KDRIs reaching 99.2%. Conclusion: This study has demonstrated the positive impact of an effective nutrition education program. However, there is a need for the continuous development and implementation of nutrition education programs to sustain these outcomes and further enhance the nutritional education experience.

A Psychological Interpretation of Fairly Tale Mokdoryung, Son of Tree (한국민담 '목(木)도령'의 분석심리학적 해석)

  • Jin-Sook Kim
    • Sim-seong Yeon-gu
    • /
    • v.25 no.2
    • /
    • pp.224-264
    • /
    • 2010
  • A brief story of the tale follows : Mokdoryung was a son of an arbor tree and a fairly. When the boy was 7-8 years old, mother-fairy returned to the sky. By using father-tree, Mokdoryung survived from the flood where he saved ants, mosquitos, and a boy with the same age. They arrived on top of the highest mountain, met an old woman with two daughters, worked as servants. With help of insects, Mokdoryung passed the trials, married to a wise daughter and 2 couples became the ancestor of the mankind. Interpretation of the tale starts with amplification of tree which symbolizes Self and Libido. As the son of the tree-spirit and a fairly from the sky, Mokdoryung is a kind of 'divine child' which represents a psychic possibility to understand archetypal nature of unconscious. Adversities of early childhood due to mother's absence regarded as necessary condition for 'divine child' to attain highest good. Flood can be compensation of absence of feminine as well as to bring a new life. The notion of father·tree becomes a kind of life-boat has to do with union of opposite(vertical phallic tree and horizontal feminine boat). Ants and mosquitoes represent upper and lower level of unconsciousness, they mediate divine power. Therefore respecting insects means respecting unconscious, and reward of insects means salvation come from unconscious. The boy saved from the flood presents emergence of psychic energy in its latent unconscious condition to create mental dynamism. The old woman is Great Mother or anima, the controller or guider of unconscious. Working as servants can be an active service for the divine marriage. Trials of separating millet from sand, and finding right direction relate to separatio, means one needs to be separated from unconscious before conunctio, union of opposite. Two sets of couple becoming ancestor of man-kind has to do with number 4 (quaternity) as well as regeneration. Although the tale includes both positive couple (Mokdoryung, wise daugther in east room). and negative couple(shadow side of Mokdoryung, step daughter in west room)as ancestors of mankind, "Good" seems to be more valued than "evil".