• Title/Summary/Keyword: Number Sense

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Effects of NEX on SNR and Artifacts in Parallel MR Images Acquired using Reference Scan

  • Heo, Yeong-Cheol;Lee, Hae-Kag;Cho, Jae-Hwan
    • Journal of Magnetics
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    • v.18 no.4
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    • pp.422-427
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    • 2013
  • The aim of this study was to investigate effects of the number of acquisitions (NEX) on signal-to-noise (SNR) and artifacts in SENSE parallel imaging of magnetic resonance imaging (MRI). 3.0T MR System, 8 Channel sensitivity encoding (SENSE) head coils were used along with an in-vivo phantom. Reference sequence of 3D fast field echo (FFE) was consisted of NEX values of 2, 4, 6, 8, 10 and 12. The T2 turbo spin echo (TSE) sequence used for exams achieved SENSE factors of 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, 3.0, 3.2, 3.5, 3.8 and 4.0. Exams were conducted five times for each SENSE factor to measure signal intensity of the object, the posterior phase-encode direction and frequency direction. And SNR was calculated using mean values. SENSE artifacts were identified as background signal intensity in the phase-encoded direction using MRIcro. It was found that SNR increased but SENSE artifacts reduced with NEX of 4, 8 and 12 when the NEX increased in reference scan. It is therefore concluded that image quality can be improved with NEX of 4, 8 and 12 for reference scanning.

Tuning Backoff Period for Enhancing System Throughput with Estimating Number of Devices in IEEE 802.15.4 Slotted CSMA/CA (IEEE 802.15.4 슬롯 기반 CSMA/CA에서 시스템 처리율 향상을 위한 단말 수 추정을 통한 백오프 기간 튜닝 기법)

  • Lee, Won Hyoung;Hwang, Ho Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.9
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    • pp.1243-1249
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    • 2018
  • In this paper, we propose a scheme that tunes the backoff period for enhancing the system throughput with estimating the number of devices in IEEE 802.15.4 slotted carrier sense multiple access with collision avoidance (CSMA/CA) networks. Since each device does not sense the channel always in IEEE 802.15.4 slotted CSMA/CA networks, a personal area network (PAN) coordinator is used to estimate the number of active devices. The PAN coordinator broadcasts an optimal backoff period for the estimated number of devices through a beacon frame. In order to estimate the number of devices in run time, a simple moving average filter is utilized. We show the performance of our proposed scheme in terms of the estimated number of devices and the system throughput. The simulation results show that our proposed scheme can obtain higher system throughput than the IEEE 802.15.4 standard.

A Study on Space of Healing focused on Light and Sense in Contemporary Spa Design (빛과 감각을 중심으로 한 현대 스파(Spa) 디자인의 치유 공간 구현에 관한 연구)

  • Park, So-Yeon;Kim, Jong-Jin
    • Korean Institute of Interior Design Journal
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    • v.22 no.6
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    • pp.241-250
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    • 2013
  • In contemporary society, spa has become one of the important healing spaces. As the present urban life has been more and more complex and competitive, space of recreation and healing are dramatically increased in terms of its number as well as location. In the past, there were three kinds of spa visitors. The first was the people who visited spas for medical reasons. The second was the people who visited spas for leisure and refreshment. The third was for social gatherings like in the ancient Rome. In present time, these three reasons are mixed together. As the spa program became rich and various, visitors tends to seek an appropriate spa environment that suits their needs. This is the main background for contemporary spa designs. In any case, concept of healing has been always the core element in spa. Light and sense have vital role to make a unique spa design. This paper aims to study different light and sense applications in contemporary spa designs. Specific focus is to find how light and sense in spa designs act to create a healing environment. 4 spa projects built in Europe after 2000 were selected and were analyzed based on the 4 light and sense characteristics. In conclusion, case analysis was summarized to suggest future possibilities.

The Influence of Teachers' Vocational Aptitude and Sense of Responsibility on Their Teaching Efficacy in Early Childhood Education and Care (보육교사의 직업적성 및 책임감이 교사효능감에 미치는 영향)

  • Chae, Jin-Young
    • Korean Journal of Childcare and Education
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    • v.12 no.2
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    • pp.57-72
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    • 2016
  • The purpose of this study was to examine the influence of teachers' vocational aptitude and sense of responsibility on their teaching efficacy in early childhood education and care. 259 teachers in ECEC were recruited from 19 daycare centers and the data were analyzed through frequency, percentage, Pearson's correlations, and stepwise regression using SPSS 18.0. The findings are as follows. First, teachers' teaching efficacy was significantly different according to their age, the number of years of teaching experiences, and education levels. Second, all degrees of teachers' vocational aptitude, sense of responsibility, and their teaching efficacy were higher than the median points. Second, teachers' efficacy relating with running class was affected most by the ability of safe management in vocational aptitude, and teaching methods in sense of responsibility. For teachers' efficacy relating to teaching, acceptability/sensitivity in vocational aptitude and motivation had the most impact. The implication was discussed in order to figure out the ways to increase teachers' efficacy.

A STUDY OF SOME TESTS OF TREND IN CONTINGENCY TABLES

  • Jee, Eun-Sook
    • The Pure and Applied Mathematics
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    • v.4 no.1
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    • pp.7-18
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    • 1997
  • Consider an $r\;\times\;c$ contingency table under the full multinomial model in which each classification is ordered. The problem is to test the null hypothesis of independence. A number of tests have been proposed for this problem. In this article we show that all of these tests can be improved on in some sense for most cases. In fact the preceding tests sometimes are inadmissible in a strict sense. Furthermore, we show by example that in some cases improved tests can yield substantially improved power functions.

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Determination of Optimal Number of AGV by Simulation (시뮬레이션에 의한 AGV 최적대수 결정)

  • Lee, Mun-Sup;Yi, Sang-Yong
    • Journal of Korean Institute of Industrial Engineers
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    • v.16 no.1
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    • pp.59-65
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    • 1990
  • In the design of AGVS (Automated Guided Vehicle Systems), one of the important problem is to determine the number of AGVs required to provide a given level of transport service. At present, there are two kind of methods to determine the number of AGVs, the one is to use the mathematical model, the other is to use the simulation technique. Among these, simulation based technique is more reliable than analytical method. In this sense, this paper intend to determine the optimal number of AGVs using personal computer simulation by SIMAN Ver.3.5.

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Effects of the Urban Farm Program on the Participants' Sense of Community (도시텃밭 운영 프로그램이 참여자 공동체의식에 미치는 영향)

  • Park, Tae-Ho;Lee, Insung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.5
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    • pp.119-128
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    • 2012
  • This study investigated the effects of urban farm program on the participants' sense of community. Three public urban farms in Seoul were selected and surveyed. The results were as follows: First, the effects of the urban farm program on the sense of community were verified by a multifaceted analysis. There were significant differences in the interaction and sense of community between urban farms with and without regular programs. Program participants showed higher level of activity, interaction and sense of community compared to non-participants. Program participation was the most important factor in the path analysis. Second, the number of participating group, residential ownership and duration were important factors in the sense of community. This implies that urban farm programs should target house owners with long duration, in particular socially disadvantaged classes such as single-family and elderly household. Third, diverse cultural programs related to the regional society gained higher satisfaction than the simple agricultural educational programs.

Correlation and Combining Ability of Plant Spreading Chracteristics in F1 Hybrids by Diallel Cross in Petunia hybrida (페튜니아 일대 잡종에서 덩굴성 관련형질의 상호관계 및 조합능력)

  • Song, Cheon Young
    • FLOWER RESEARCH JOURNAL
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    • v.17 no.3
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    • pp.179-184
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    • 2009
  • The correlation and combining abilities related with plant spreading characteristics of plant height, plant width, stem length, internode length, number of stem, number of leaves, and number of flower were studied in the $F_1s$ of 10 crosses from the partial five-parent diallel cross in Petunia hybrida. The plant width showed highly positive correlation with internode length, and number of flower. The mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for plant width, number of stem, number of leaves, and number of flowers. The mean square values of GCA were greater than those of SCA for all the characters, showing preponderance of additive gene actions for these characters. The lines of D and I for plant width and length of stem showed relatively high GCA effects. The crosses of $D{\times}I$, $F{\times}I$, and $G{\times}I$ exhibited high SCA effects on plant width, especially $G{\times}I$ effected in internode length and number of flower. The broad sense heritability was generally high compared to narrow sense one. Plant width and stem length, and internode length related to spreading growth showed the higher heritability than the other characters in the broad and narrow sense.

Inter-Relationship and Combining Ability of Plant Growth in F1 Hybrids of Petunia hybrida (페튜니아 일대 잡종에서 생육관련 형질의 상호관계 및 조합능력)

  • Song, C.Y.;Hong, K.H.;Kang, Y.K.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.3 no.1
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    • pp.85-93
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    • 2001
  • The inter-relationship and combining abilities of characters for leaf length, leaf width, branch number, leaf number, leaf area, fresh weight and dry weight were studied in the F1 combination of 15 crosses from the partial six-parent diallel cross in Petunia hybrida. The leaf area, fresh weight and dry weight showed high positive correlation together with the other growth characters such as leaf length, leaf width, branch number, leaf number. The mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for all the growth characters. The estimates of variance components of SCA were greater than those of GCA for all the characters, showing preponderance of non-additive gene actions for these characters. GCA effect was high in the lines of D and G for leaf length and fresh weight, and in the lines of C and D for branch number, leaf number, leaf area and fresh weight. The crosses of D×E, D×G, and E×G exhibited high SCA effect for all the growth characters such as leaf length, leaf width, branch number, leaf number, leaf area, fresh weight, and dry weight. The broad sense heritability was generally high compared to narrow sense one in the 7 characters. The highest heritability of the broad and narrow sense was shown in the leaf width and dry weight.

Satisfaction with Department Selection and Changes in a Sense of Employment Among Some Students Majoring in Dental Hygiene (일부 치위생과 재학생의 학과선택 만족도 및 취업의식변화)

  • Kim, Jin-Soo;Lim, Kun-Ok
    • Journal of Korean society of Dental Hygiene
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    • v.6 no.2
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    • pp.103-113
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    • 2006
  • The purpose of this study was to examine and analyze motivation of entrance into the college, knowledge prior to the entrance, satisfaction with their major, and a sense of employment after graduation among students majoring in dental hygiene at some colleges and subdivide them by grades for comparative analysis to determine the progress of changes in general characteristics, department satisfaction, and a sense of employment among students majoring in dental hygiene for the recent three years and provide basic data for improving dental hygienic education. Questionnaires were distributed to 520 students majoring in dental hygiene at some college in South Chungcheong, South Jeolla, and North Jeolla Provinces, followed by explanation of the purport of the research and the content of the questionnaire; after completion, 513 copies were used for analysis with exception of 7 copies with insincere responses. The analysis of the data examined resulted in the following conclusions: First, Changes in Department Satisfaction among Students Majoring in Dental Hygiene As for motivation of entrance into a college, less and less students chose the department of dental hygiene through recommendation by parents or seniors while more and more students chose their major due to easy employment. Less and less students obtained information on the department from a college application guidebook while more and more students obtained it through Internet. There was also a gradual increase in prior knowledge about the department and in satisfaction with their major. More and more students had no will to change their course. Second, Changes in a Sense of Employment among Students Majoring in Dental Hygiene There was a gradual decrease in the number of students who would follow friends' or their own decision in selecting workplace but an increase in the number of those who would follow their professors' opinion. There was a gradual increase in the number of students who wanted to be employed in workplace with good social perception; many students wanted to be employed in a personal dental clinic, a general hospital, or a public health center; and more and more students also wanted to be employed in a school dental health center or to become a government official or an educator.

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