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Comparison of Wedge Factors of Dynamic Wedge and Physical Wedge (기능상쐐기와 물질쐐기의 쐐기인수의 비교)

  • Kim Jae Sung;Kang Wee-Saing
    • Progress in Medical Physics
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    • v.15 no.4
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    • pp.237-246
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    • 2004
  • Even though the wedge factor was defined by ICRU, RTPS uses other definition different from the wedge factor to consider the wedge effect to correct dose. Because the factors with different concept are defined in a very different way, replacement of different factor could make severe error of dose and is unacceptable because their values are very different from each other. Radiotherapy machine installed in department includes physical wedges and function of dynamic wedge by upper jaws, and Eclipse and Pinnacle$^{3}$ such as RTPS are used. The wedge factors, relative wedge output factors and wedge field output factors of physical wedges and dynamic wedges were measured by an ionization chamber in water phantom. They are analyzed and compared in according to wedge position, field size, wedge angle, X-ray quality, measurement condition. Wedge factor, relative wedge output factors and wedge field output factors of dynamic wedges comparing physical wedges have an effect of several factors. Main factors effecting to the factors of dynamic wedges were field size and wedge angle. Beam quality of X-ray introduces a few effect to the factors. Because the factors related to wedge and defined with different concepts are different from each other, to reduce dose error it should be input by values proper to RTPS.

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A Study on the Understanding of the Base Area of Solid Figures in the Elementary Mathematics (초등수학에서 입체도형의 밑넓이 이해에 대한 연구)

  • Kim, Sung Joon
    • Journal of the Korean School Mathematics Society
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    • v.17 no.2
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    • pp.167-191
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    • 2014
  • In this study, we investigate the term-sets of 'base' or 'bottom': 'the bottom side of a polygon' and 'the base side (of a geometrical figure)'. And we study the concept of 'the base area' in the solid figures and the formula of 'the bottom dimensions'. We start from the 6th grade math problem: 'Find the bottom dimension of the rectangular.' The primary answer is that it does not use the term('the bottom dimensions') in the elementary mathematics. However, in the middle school mathematics, 'the base area' is used as means of 'the area of one bottom side', which is not explained anywhere from the elementary mathematics to middle school mathematics. In addition, the base is defined and 'the surface area' and 'the side area' is taught in the elementary mathematics, so we naturally think of 'the base area'. Therefore we first investigate the term-sets of 'base' or 'bottom' which has two elements: 'the bottom side of a polygon' and 'the base side (of a geometrical figure)'. Next we discuss 'the base area' through curriculum and textbooks, dictionary definitions and so on. In addition, we survey pre-service teachers and teachers about the solid figures and analyse the understanding of 'the base side' and 'the base area' comparatively. In particular, we compare the changes and the tendency of correct answers from the first question to the last question. As a result, we verify 'the cognitive gap' between the elementary mathematics and the middle school mathematics, we suggest the teaching of 'the base area' and succession subjects to teach figure domain in the elementary mathematics.

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First to Third Graders Have Already Established (분수 개념에 대한 초등학생들의 비형식적 지식 분석 - 1${\sim}$3학년 중심으로 -)

  • Oh, Yu-Kyeong;Kim, Jin-Ho
    • Communications of Mathematical Education
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    • v.23 no.1
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    • pp.145-174
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    • 2009
  • Based on the thinking that people can understand more clearly when the problem is related with their prior knowledge, the Purpose of this study was to analysis students' informal knowledge, which is constructed through their mathematical experience in the context of real-world situations. According to this purpose, the following research questions were. 1) What is the characteristics of students' informal knowledge about fraction before formal fraction instruction in school? 2) What is the difference of informal knowledge of fraction according to reasoning ability and grade. To investigate these questions, 18 children of first, second and third grade(6 children per each grade) in C elementary school were selected. Among the various concept of fraction, part-whole fraction, quotient fraction, ratio fraction and measure fraction were selected for the interview. I recorded the interview on digital camera, drew up a protocol about interview contents, and analyzed and discussed them after numbering and comment. The conclusions are as follows: First, students already constructed informal knowledge before they learned formal knowledge about fraction. Among students' informal knowledge they knew correct concepts based on formal knowledge, but they also have ideas that would lead to misconceptions. Second, the informal knowledge constructed by children were different according to grade. This is because the informal knowledge is influenced by various experience on learning and everyday life. And the students having higher reasoning ability represented higher levels of knowledge. Third, because children are using informal knowledge from everyday life to learn formal knowledge, we should use these informal knowledge to instruct more efficiently.

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Design and Performance Evaluation of Small Size Counting and Imaging Gamma Probe System (소형 계수용 및 영상용 감마프로브 시스템의 설계와 성능평가)

  • Yang, Myo-Geun;Kwark, Cheol-Eun;Sim, yong-Geol;Kim, Hee-Joung;Choi, Yong;Chung, Jung-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • Journal of Biomedical Engineering Research
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    • v.18 no.3
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    • pp.291-299
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    • 1997
  • As a microimaging device detecting gamma rays emitted from small lesions or tumors during operation, the intraoperative surgical probe has been proposed and is now under development. We have designed a multipurpose portable gamma prove system and evaluated the performance both for the absolute counting purpose of residual radioactivities and for the localizing capability of gamma events using the NaI(Tl) crystal and two types of photomultiplier tubes(PMTs). Counting efficiencies in the range of routine clinical use of radiation dose were measured using the assembly of single channel PMTs and 0.5 inch thick NaI(Tl) crystal of 1 inch diameter. The positioning of gamma events for imaging purpose requires the multiple channel PMTs with appropriate positioning electronics. We have designed a simple and reliable positioning circuit based on the concept of modified Anger. In preliminary experiments using the multiple channel PMT of 3 inch diameter and the dim lighth source, we were able to trace and localize the correct position with reduced positioning error by the use of two multiplier/divider chipset and simplified peripherals. The energy resolutions for the counting gamma probe measured as full width at half maximum(FWHM) for Cs-137, F-18, Tc-99m were 12%, 13%, and 36%, respectively. The spatial resolution for the imaging gamma probe measured as FWHM for green LED was 2.9 mm. The results indicate that the currently developing probe is very promising and could be very useful for many applications in nuclear medicine. Future studies will include developing collimators, improving interface hardwares, and evaluating the system with clinical data.

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Generalization of Window Construction for Subsequence Matching in Time-Series Databases (시계열 데이터베이스에서의 서브시퀀스 매칭을 위한 윈도우 구성의 일반화)

  • Moon, Yang-Sae;Han, Wook-Shin;Whang, Kyu-Young
    • Journal of KIISE:Databases
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    • v.28 no.3
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    • pp.357-372
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    • 2001
  • In this paper, we present the concept of generalization in constructing windows for subsequence matching and propose a new subsequence matching method. GeneralMatch, based on the generalization. The earlier work of Faloutsos et al.(FRM in short) causes a lot of false alarms due to lack of the point-filtering effect. DualMatch, which has been proposed by the authors, improves performance significantly over FRM by exploiting the point filtering effect, but it has the problem of having a smaller maximum window size (half that FRM) given the minimum query length. GeneralMatch, an improvement of DualMatch, offers advantages of both methods: it can use large windows like FRM and, at the same time, can exploit the point-filtering effect like DualMatch. GeneralMatch divides data sequences into J-sliding windows (generalized sliding windows) and the query sequence into J-disjoint windows (generalized disjoint windows). We formally prove that our GeneralMatch is correct, i.e., it incurs no false dismissal. We also prove that, given the minimum query length, there is a maximum bound of the window size to guarantee correctness of GeneralMatch. We then propose a method of determining the value of J that minimizes the number of page accesses, Experimental results for real stock data show that, for low selectivities ($10^{-6}~10^{-4}$), GeneralMatch improves performance by 114% over DualMatch and by 998% iver FRM on the average; for high selectivities ($10^{-6}~10^{-4}$), by 46% over DualMatch and by 65% over FRM on the average.

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Performance Analysis of the Channel Equalizers for Partial Response Channels (부분 응답 채널을 위한 채널 등화기들의 성능 분석에 관한 연구)

  • Lee, Sang-Kyung;Lee, Jae-Chon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8A
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    • pp.739-752
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    • 2002
  • Recently, to utilize the limited bandwidth effectively, the concept of partial response (PR) signaling has widely been adopted in both the high-speed data transmission and high-density digital recording/playback systems such as digital microwave, digital subscriber loops, hard disk drives, digital VCR's and digital versatile recordable disks and so on. This paper is concerned with adaptive equalization of partial response channels particularly for the magnetic recording channels. Specifically we study how the PR channel equalizers work for different choices of desired or reference signals used for adjusting the equalizer weights. In doing so, we consider three different configurations that are actually implemented in the commercial products mentioned above. First of all, we show how to compute the theoretical values of the optimum Wiener solutions derived by minimizing the mean-squared error (MSE) at the equalizer output. Noting that this equalizer MSE measure cannot be used to fairly compare the three configurations, we propose to use the data MSE that is computer just before the final detector for the underlying PR system. We also express the data MSE in terms of the channel impulse response values, source data power and additive noise power, thereby making it possible to compare the performance of the configurations under study. The results of extensive computer simulation indicate that our theoretical derivation is correct with high precision. Comparing the three configurations, it also turns out that one of the three configurations needs to be further improved in performance although it has an apparent advantage over the others in terms of memory size when implemented using RAM's for the decision feedback part.

Parish Nursing : A New Challenge for Primary Health Care (지역교회간호(Parish Nursing) - 일차건강간호를 위한 새로운 도약)

  • No, Yu-Ja;Baek, Yeong-Mi
    • The Korean Nurse
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    • v.37 no.2
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    • pp.53-62
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    • 1998
  • ursing as a profession is characterized by its holistic, mind-body-spirit approach to the patient. Also, nurses have historically been the leaders in health education and promotion. Parish nursing has a great potential for providing primary preventive health care. services as well as assisting people to access the health care system. While working in the community, parish nurses see the church as the new arena for delivering health care services. The parish nurse program was introduced by Granger Westberg in 1984. The concept of parish nursing is based on several beliefs; health is multidimensional and affects all aspects of an individual-physical, psychological, social, and spiritaul being. Parish nursing is one model in which churches can cooperatively work with health care institutions to address the needs of their parishioners. The role of the parish nurse is emphasized in four basic area: a) health education, b) health counseling, c) referal services, and d) facilitation and organization of support groups within the congregation. The parish nurse programs work chiefly in congregation or commuity where a certain language of faith is ready at hand. This means that the parish nurse works in an ecology of meanings and care which encourages the drawing on the message of God's grace, the practices and habits it encourages. The parish nurse may be involved in the church's health ministries and may work on either paid or volunteer basis; however, one of the most important qualification of the parish nurse is to have the nursing knowledge and skills to practice within the standards of Nursing Practice Act. The completion of standards of practice for professional nurses practicing as parish nurses had been identified as a priority by the HMA Executive Board (1996, HMA). In conclusion, parish nursing promotes health and healing by empowering the faith community, family, or individual to incorporate health and healing practices. There are several preconditions that should proceed to establish the foundation for successful development of the parish nursing program in Korea. First, reciprocal relationship with home health nursing should be considered. Second, correct terms and concepts of parish nursing should be studied and understood. Third, systematic study and investigation should be followed for further development of parish nursing. Fourth, strengths and weaknesses of different models should be studied to develop proper model of parish nursing for Korean situation. Finally, consensus of standardized education program and corporation with various religious communities as well as health institutions should be established. When these preconditions are met, the role of parish nursing as a new program for the promotion of holistic health will be established.

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The syntax comparative research of Korean and Chinese Adjectives (한·중 형용사 통사론적 비교 연구 - 형용사의 특징과 기능을 중심으로)

  • Dan, Mingjie
    • Cross-Cultural Studies
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    • v.25
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    • pp.483-527
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    • 2011
  • The main focus of this dissertation is the comparative research of Korean and Chinese adjectives. With the comparison and contrast of the concepts, features and usages of Korean and Chinese adjectives, we have concluded some similarities and differences. The aim is to help Chinese learners who study Korean better understand the features of Korean adjectives and use them more easily. Korean belongs to 阿?泰?族 and expresses meanings with pronunciation; however, Chinese belongs to ?藏?族 and expresses meanings with characters. There are many similarities between those two languages that look completely different, such as pronunciation and grammar at some extent. Even the Chinese words in Korean are quite similar to Chinese. However, the two languages are very different from each other, from the detailed grammatical view. For instance, the auxiliary word in Korean and Chinese is completely different. Then, Korean has a concept: ?尾that does not exist in Chinese at all. Especially, about categories of words, it is very important and difficult to distinguish adjective and verb for the Chinese Korean-learners. One reason of the challenge is that some Korean adjectives are categorized as verbs in Chinese. For example, "like", "dislike", "fear" in Korean are "psychological adjective" however, they are "psychological verb" in Chinese. The differences in categorization always mislead learners in understanding whole articles. At the same time, they cause more problems and difficulties in learning other grammatical items for Chinese Korean-learners. Based on that, the dissertation is helpful for Chinese learners who are studying Korean. Starting from the most basic concepts, the second chapter focuses on analyzing the similarities and differences between Korean and Chinese adjectives. The correct understanding of adjective is the basis of accurate learning of it. With the comparison of concepts and primary comprehension of adjective, the third chapter analyzes in detail about the features of Korean and Chinese adjective from grammar and meaning. Based on those features, we analyze the detailed usages of Korean and Chinese adjective in articles; especially we provide the detailed explanations of adjective changes in different tense and ?尾 changes in using with noun and verb. The fourth chapter emphasizes the similarities and differences of adjective meanings in Korean and Chinese. We have provided the comparative analyses from six different views, which could be helpful for Chinese Korean-learners. Until now, there are few comparative studies of Korean and Chinese adjectives. About this dissertation, some limitations also exist in such an area. However, we hope it could provide some help for Chinese Korean-learners, and more profound research will be developed in the future.

A Study on the Structure of Soshaewon Landscape Garden Featuring Borrowed Scenery - Focusing on the Soshaewon Sisun and the Thirty Poems of Soshaewon - (차경(借景)을 통해 본 소쇄원 원림의 구조 - 「소쇄원시선(瀟灑園詩選)」과 「소쇄원30영」을 중심으로 -)

  • So, Hyun-Su
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.4
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    • pp.59-69
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    • 2011
  • In this study I examined the status of the borrowed scenery of Soshaewon and analyzed the structure of Byeolseo Gardenusing "Soshaewon Sisun(瀟灑園詩選)", which consists of a collection of poems written by people who visited Soshaewon during Joseon Dynasty with bibliographical explanations and "the Thirty Poems of Soshaewon", written by Yang, Gyeong Ji who was the fifth generation from Yang, San Bo. This study expanded the concept of borrowed scenery to include visual, synaesthetic, temporary and ideal features based on the theory of borrowed scenery in "Won Ya(園冶)", which emphasized the time feature and change, and explained that a landscape garden could be perfected by the presence of borrowed scenery beyond the previous borrowed landscape which was recognized through visual value. It would be correct to understand that the visitors to Soshaewon accomplished imaginary scenery(意境) through recreating Soshaewon into a space that stimulated poetic sentiment and aesthetic sensitivity by creating four types of borrowed scenery of a landscape garden composed of both real and fictitious scenery. At present the scope of Soshaewon tends to be limited to its inner garden covering the stream garden. However, in this study I took a new approach in defining the scope of Soshaewon, providing three types of Byeolseo Garden area ; more specifically, the expanded scope of Soshaewon covers the outer garden that secured the outlook of visual, temporary and synaesthetic objects for borrowed scenery and the right to use by purchasing more area by the descendants and the ideological garden that was composed of the ideal borrowed scenery created by the Confucian friends and colleagues who praised the Jeungamcheon Stream area and various famous mountains longing for the immortal world.

A Comparison of the Clinical Competence, Knowledge of Patient Safety Management and Confidence of Patient Safety Management according to Clinical Practice Experience of Nursing Students

  • Lim, Jae-Ran;Song, Hyo-Suk
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.7
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    • pp.65-73
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    • 2021
  • The purpose of this study is to cornpare the differences in clinical competence, knowledge of patient safety management and confidence of patient safety management according to the clinical practice experience of nursing students, Of the 73 nursing students who experienced clinical practice and 35 nursing students who did not experience, a total of 108 students in the third grade were analyzed, In the results of this study, clinical competence(t=.88, p=.377) knowledge of patient safety management(t=-.29, p=.773), and confidence of patient safety management(t=1.11, p=.267) the difference between was not statistically significant in the two groups. In the two groups, the score of the sub-area according to each variable is the lowest. First, the sub-area of the nursing process a lowest score in clinical competence, and the second, the sub-area of measuring knowledge about concept of near miss was the Knowledge of patient safety management. The score was the lowest in, and thirdly, the sub-area of writing an incident report when an error occurred had the lowest score in confidence of patient safety management. Therefore, in order to improve the quality of clinical competence of nursing students, it is necessary to develop a strategic educational guideline to improve the clinical practice education environment, to improve patient safety management capabilities and to cultivate correct attitudes toward patient safety management.