• Radiation Oncology Journal
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• v.15 no.1
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• pp.71-78
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• 1997

Purpose : To collect beam data for dynamic wedge fields using conventional measurement tools without the multi-detector system, such as the linear diode detectors or ionization chambers. Materials and Methods : The accelerator CL 2100 C/D has two photon energies of 6MV and 15MV with dynamic wedge an91es of 15o, 30o, 45o and 60o. Wedge transmission factors, percentage depth doses(PDD's) and dose Profiles were measured. The measurements for wedge transmission factors are performed for field sizes ranging from $4\times4cm^2\;to\;20\times20cm^2$ in 1-2cm steps. Various rectangular field sizes are also measured for each photon energy of 6MV and 15MV, with the combination of each dynamic wedge angle of 15o 30o. 45o and 60o. These factors are compared to the calculated wedge factors using STT(Segmented Treatment Table) value. PDD's are measured with the film and the chamber in water Phantom for fixed square field. Converting parameters for film data to chamber data could be obtained from this procedure. The PDD's for dynamic wedged fields could be obtained from film dosimetry by using the converting parameters without using ionization chamber. Dose profiles are obtained from interpolation and STT weighted superposition of data through selected asymmetric static field measurement using ionization chamber. Results : The measured values of wedge transmission factors show good agreement to the calculated values The wedge factors of rectangular fields for constant V-field were equal to those of square fields The differences between open fields' PDDs and those from dynamic fields are insignificant. Dose profiles from superposition method showed acceptable range of accuracy(maximum 2% error) when we compare to those from film dosimetry. Conclusion : The results from this superposition method showed that commissionning of dynamic wedge could be done with conventional dosimetric tools such as Point detector system and film dosimetry winthin maximum 2% error range of accuracy.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.345-351
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• 1996

Studies on extraction and color characteristics of purple sweet potato (PSP) pigment were performed to provide the basic information for the utilization of PSP as a new source of natural food colorant. PSP pigment was extracted well with the polar solvents such as distilled water, ethanol, and methanol. but hardly extracted with the non-polar solvents. Among the tested solvents, 20% ethanol solution containing 0.1% citric acid was found to be the most efficient for extraction of the pigment from PSP. PSP contained high amount of pigment not only in the epidermis but also in the flesh of the potato. The PSP pigment was heat stable even under pretreatments such as autoclaving and blanching of the potato before extraction. The optimum temperature of the extraction for the PSP Pigment was decided to be $30^{\circ}C$ by considering the stability and the rate of extraction. The pigment was markedly influenced by the change of pH. The color of the pigment solution was red at the pH range of $1.0{\sim}3.0$, became blue at $7.0{\sim}8.0$, then turned green at $9.0{\sim}10.0$. A characteristic batho-chromic shift of the pigment solution was observed as the pH of the solution increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1243-1252
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• 2017

There are limited programs for low sodium intake based on the nutrition education model for housewives who cook family meals. The objective of this study was to evaluate the effects of model-based nutrition programs for low sodium intake among housewives residing in Seoul by incorporating social cognitive theory. A questionnaire survey before and after education was conducted on 140 housewives who participated in the 'Low Sodium Nutritional Education Program' delivered by a district public health center for 12 weeks from November 2015 to January 2016. The contents of the nutrition education program and program evaluation items were based on the action plans for 'Less Sodium Healthy Practice' suggested by the Ministry of Food and Drug Safety. The results show that program participants showed a lower preference for sodium, higher selection of low sodium dishes from restaurants or cafeteria if available, and increased awareness of the need of restaurants to serve low sodium dishes compared to before. In terms of behavioral changes, there were significant improvements in checking nutrition labeling and selection of foods with low sodium, use of low sodium food products, use of natural seasonings to reduce salt intake, and consumption of fast foods and processed foods. On the other hand, requesting less salty meals when ordering and introducing restaurants or cafeterias with healthy and low sodium menus turned out to be difficult to put into practice. In conclusion, the nutrition education program for sodium intake reduction for housewives was effective in increasing knowledge, environment recognition, and behaviors related to low sodium intake but not behaviors related to physical environmental factors. Therefore, further nutrition education programs and practices for sodium intake reduction should be comprehensively implemented with improvement of physical environments for low sodium intake.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.43-52
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• 2006

Topical fluoride application for children is a widely peformed procedure in the field of pediatric dentistry to prevent dental caries. However, it is recently recognized as having some unwanted effects on several esthetic restorative materials as it roughens the surface of the restorative materials. The aim of this study was to evaluate the surface changes in composite resins to topical fluoride. Composite resins(Z $250^{(R)}$, Ultraseal $XT^{(R)}$ Filtek $flow^{(R)}$ $Revolution^{(R)}$, $Denfil^{(R)}$) in topical fluoride agents were immersed and their surface roughness, weight loss and SEM were evaluated. The results were as follows : 1. The 4 minutes-immersion groups showed more roughened surface than 1 minute-immersion groups and the control groups showed the smoothest surface among all the materials, and there was statistically significant difference except the revolution between the groups. 2. There was no significant difference between the 1 minute-immersion groups and 4 minutes-immersion groups in weight loss. 3. The experimental group treated with topical fluoride gel showed the generally mere roughened surface than control group in the SEM findings.

• Journal of The Korean Association For Science Education
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• v.5 no.1
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• pp.49-61
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• 1985

In this study, I compared and analyzed the new and old secondary school science textbooks to find the charateristics of them and the differences between them. The results of the study are the following. Major concepts in the new textbook are almost similar to those in the old one. The-new textbook reinforces the functions of the introudction and checking the result of learning, and presents more and diverse learning materials and reduces the degree of learning difficulty by omitting the several abstract knowledges and mathematical formulas which can be understood through formal operational thinking. The results show that the new textbook is more effective in arousing student's interest and curiosity there fore it increases the efficiency of learning. But the new textbook is less suitable for inquiry because it is mainly composed of explanation and fact rather than experiment and observation. I think that this is the result from the actual approach to the real conditions of school when the curriculum was reformed and the new textbook was written.

• Journal of Korean Home Economics Education Association
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• v.19 no.4
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• pp.91-117
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• 2007

This study was to compare the contents and practical problems addressed, the process of teaching-learning method, and evaluation method of Korean Home Economics curriculum and of the Oregon and Ohio's Practical Problem Focused Family & Consumer Sciences Curricula. The results are as follows. First, contents of Korean curriculum are organized by major sub-concepts of Home Economics academic discipline whereas curricular of both Oregon and Ohio states are organized by practical problems. Oregon uses the practical problems which integrate multi-subjects and Ohio uses ones which are good for the contents of the module by integrating concerns or interests which are lower or detailed level (related interests). Since it differentiates interest and module and used them based on the basic concept of Family and Consumer Science, Ohio's approach could be easier for Korean teachers and students to adopt. Second, the teaching-learning process in Korean home economics classroom is mostly teacher-centered which hinders students to develop higher order thinking skills. It is recommended to use student-centered learning activities. State of Oregon and Ohio's teaching-learning process brings up the ability of problem-solving by letting students clearly analyze practical problems proposed, solve problems by themselves through group discussions and various activities, and apply what they learn to other problems. Third, Korean evaluation system is heavily rely on summative evaluation such as written tests. It is highly recommended to facilitate various performance assessment tools. Since state of Oregon and Ohio both use practical problems, they evaluate students mainly based on their activity rather than written tests. The tools for evaluation include project documents, reports of learning activity, self-evaluation, evaluation of discussion activity, peer evaluation in a group for each students for their performance, assessment about module, and written tests as well.

• Journal of Korean Home Economics Education Association
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• v.31 no.3
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• pp.91-116
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• 2019

The purpose of this study is to examine the meaning of Changemaker education and to investigate the significance of Changemaker education in home economics education through a study of growth of learners applying the TEMPS program. To this end, first, the concept of Changemaker education was defined. Changemaker education is an education that changes society in a positive direction through a process of thinking about, learning about, making, and participating(playing) in various problems that we face in real life and drawing out solutions and share he solutions with others. Second, in this reasearch, the direction of Changemaker education is to make them interested in social problems and solve it and to make both the family and the career life happy and healthy by collaborating with other people. The scope of the contents is defined as "the selection of the content elements of the five domains of the child family, diet nutrition, clothing, housing and consumer life". As a way of teaching, we suggested that the TEMPS phase is followed so that the session purpose is achieved. Third, the Changemaker program consists of five steps of TEMPS among the five key ideas of Changemaker education. T(Thinking) is the step of understanding the problem and thinking about how to solve it, and E(Education) is getting the background for the next step. M(Making) is a step to create a target for problem solving, and P(Participation) and P(Play) are steps to Participation and enjoy. S(Share) is a step of changing the society through the result display, SNS sharing, and class presentation. In this study, 12 programs for middle school and 15 programs for high school were developed on the basis of TEMPS level. Each of the programs consists of 2 to 12 unit hours, which add up to 68 hours in the middle school program and 68 in high school. The learners who participated in the Changemaker program for one year (March 2, 2018~December 31, 2018) will experience improvement in many aspects including the linkage of life and education, practical ability, self-directed learning, self-esteem, sense of achievement and self-reflection, sensory observation, and so on.

• Journal of the Korean Institute of Landscape Architecture
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• v.17 no.1
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• pp.43-54
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• 1989

In recent years plants have increasingly become in inferior part of the interior designing of large buildings. In 28 large buildings selected at random in Seoul City have been subjected to studies on utilization status of fille interior landscape plants. The results obtained were as follows. 1. Plant class found in Interior of large buildings were 59 class, especially Dracaena were the most predominent plants among them, and then comes Monstera, Phiodendron, Schefflera, and Washingtonia in that order. 2. The most abundant ornamental plant cultivars were Monstera adansoii(Monstera perutusa cv.), and then comes Schefflera arboricora(Schefflera Hong Kong cv.), Washingionia rubusta (Washingtonia palm). Rhapis excelsa, and Diffenbachia(Hawaii Snow cv.) in that order. 3. Foliage plants among the interior landscape plants showed 99.5 percent and Woody plants and Bonsai plants showed each 0.4, 0.1 percent. 4. Climbing foliage plants found in 28 large building observed For the present study were 9 cultivar, and the most abundant plants were Hedera (pittsburgh cv.) and Epipremnum (Marble Queen cv.) pl anted to clustered planting. 5. A majority of plants used to plastic pot, and most of 71an1s place on the floor. 6. Height of plants ranging less then 50cm were more frequently found, but ranging from 50cm to 2.0m were 4.3 percent and the most predominent height of plants were Canariensis showed 4m in the large buildings. 7. Interior light intensity in large building were shortage, therefore artificial lamp for formal growing needed to be equipped. 8. Purpose growth of interior plants were to in order visitors. 9. 7he superintendents prefered to used pot-stand. 10. The most important environment factor for plant growing were light, humidity, and water.

• The Transactions of the Korea Information Processing Society
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• v.1 no.3
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• pp.367-379
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• 1994

This paper describes scheduling algorithms of the UNIX operating system and shows an analytical approach to approximate the average conditional response time for a process in the UNIX operating system. The average conditional response time is the average time between the submittal of a process requiring a certain amount of the CPU time and the completion of the process. The process scheduling algorithms in thr UNIX system are based on the priority service disciplines. That is, the behavior of a process is governed by the UNIX process schuduling algorithms that (ⅰ) the time-shared computer usage is obtained by allotting each request a quantum until it completes its required CPU time, (ⅱ) the nonpreemptive switching in system mode and the preemptive switching in user mode are applied to determine the quantum, (ⅲ) the first-come-first-serve discipline is applied within the same priority level, and (ⅳ) after completing an allotted quantum the process is placed at the end of either the runnable queue corresponding to its priority or the disk queue where it sleeps. These process scheduling algorithms create the round-robin effect in user mode. Using the round-robin effect and the preemptive switching, we approximate a process delay in user mode. Using the nonpreemptive switching, we approximate a process delay in system mode. We also consider a process delay due to the disk input and output operations. The average conditional response time is then obtained by approximating the total process delay. The results show an excellent response time for the processes requiring system time at the expense of the processes requiring user time.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.341-348
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• 2018

To investigate the effect of light sources on the growth and photosynthesis of the dwarf apple rootstock M.9 for the production of standard seedlings, the plants were cultivated in a controlled environment for 6 weeks. The sources of light are six treatments [Red (R), Blue (B), White (W), RBUV (R7B3 containing UV-A), RBW (R3B1W1), SMF (high pressure sodium + metal halide + fluorescent lamp) under $154{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Growth characteristics of apple seedlings varied depending on artificial light source at 3 weeks and 6 weeks. The plant height of apple seedling was high in the R, RBUV, RBW, and SMF light sources at 3 weeks, and in the R light at 6 weeks. There was no significant difference on stem diameter among the treatments at 3 weeks, but showed high in RBUV and RBW light at 6 weeks. Leaf number was the highest in RBUV light at 3 and 6 weeks. The chlorophyll content (SPAD value) was high in the B and RBUV light at 3 weeks, but it was not significant at 6 weeks. The growth rate to height of the R light (1.12mm/day) was the highest among the treatments, followed by RBUV, RBW, SMF, W and then B. Leaf area was the highest in RBUV and RBW lowest in B. Specific leaf area was high in W and fresh and dry weight were high in RBUV. The photosynthetic rate at 6 weeks was highest in the B and lowest in the R. Stomatal conductivity and transpiration rate were higher in the B and W compared to the other light sources. Therefore, we are considered that light sources for growth of dwarf apple rootstock M.9 seedlings are suitable the R, RBUV, and RBW light sources with a high mixing ratio of Red and Red +Blue.