• Title/Summary/Keyword: Experimental designs

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Signal and Noise Analysis of Indirect-Conversion Digital Radiography Detectors Using Linear-systems Transfer Theory (선형시스템 전달이론을 이용한 간접변환방식 디지털 래디오그라피 디텍터의 신호 및 잡음 분석)

  • Yun, Seung-Man;Lim, Chang-Hwy;Han, Jong-Chul;Joe, Ok-La;Kim, Jung-Min;Kim, Ho-Kyung
    • Progress in Medical Physics
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    • v.21 no.3
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    • pp.261-273
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    • 2010
  • For the use of Indirect-conversion CMOS (complementary metal-oxide-semiconductor) detectors for digital x-ray radiography and their better designs, we have theoretically evaluated the spatial-frequency-dependent detective quantum efficiency (DQE) using the cascaded linear-systems transfer theory. In order to validate the developed model, the DQE was experimentally determined by the measured modulation-transfer function (MTF) and noise-power spectrum, and the estimated incident x-ray fluence under the mammography beam quality of W/Al. From the comparison between the theoretical and experimental DQEs, the overall tendencies were well agreed. Based on the developed model, we have investigated the DQEs values with respect to various design parameters of the CMOS x-ray detector such as phosphor quantum efficiency, Swank noise, photodiode quantum efficiency and the MTF of various scintillator screens. This theoretical approach is very useful tool for the understanding of the developed imaging systems as well as helpful for the better design or optimization for new development.

Effectiveness of Community-Based Rehabilitation After Traumatic Brain Injury : A Systematic Review (지역사회 재활이 외상성 뇌손상 환자에게 미치는 효과: 체계적 고찰)

  • Park, Young-Ju;Chang, Moon-Young;Kim, Kyeoung-Mi
    • The Journal of Korean society of community based occupational therapy
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    • v.2 no.1
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    • pp.13-23
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    • 2012
  • Objective : The purpose of this study was to provide evidence for effectiveness of community-based rehabilitation methods and results after traumatic brain injury through systematic review. Methods : The materials of the research were collected by retrieving research items in the areas of "community-based rehabilitation" and "traumatic brain injury" from the data base of Ovid and PubMed. Among the collected materials, 7 research results are suggested concerning the effectiveness of rehabilitation in community-based after traumatic brain injury in terms of subjects, measurement tools, cure methods and results. Results : Characteristics of subjects were diverse in numbers of subject, age, level of impairment and duration of disease. Research designs were all experimental studies and the most outcome parameters of community-based rehabilitation was occupational performance(27.7%). Cure methods were used occupational therapy programs concerning rehabilitation programs, cognitive therapy, cognitive behavioral therapy and home based occupational therapy. Conclusion : The results implied that community-based rehabilitation is effective on occupational performance, participation, prevention, and occupational justice, partially effective on adaptation, health and wellness, and non effective on the role competence. It is suggested the future research need to be done to develop intervention programs and studies in every types.

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Development of Slacks Pattern for Old Aged Abdominal Obese Women (복부 비만 노년 여성을 위한 슬랙스 패턴 개발)

  • Kim, Seon-Ok;Kweon, Soo-Ae;Yoo, Jung-Ja
    • Korean Journal of Human Ecology
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    • v.18 no.1
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    • pp.157-166
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    • 2009
  • This study was conducted to evaluate the differences in external appearances and functional qualities between the slacks which were patterned on existing designs and on a new design in order to improve on their level of comfort of ready-made clothes for abdominally fat women. Five abdominally fat women in their 60's were chosen as experimental participants. Twenty-four external evaluation items, and seven different actions involving six moving parts of the body were investigated with a 5-level scale in the repeated wearing test. The results were analyzed by statistical methods. The newly designed pattern in this study was definitely superior to the other two patterns(L-type and K-type) on the external appearance evaluation. The newly pattern removed a waist belt and a dart from the front part of the garment and gave surplus space around the waist. It prevented superfluous wrinkles at the abdominal region and thighs. The superfluous wrinkles at the side regions also disappeared due to the length (inseam) reduction from waist to crotch. The newly pattern made the center-line of the back side slightly sloped to the main pattern in order to remove the drooped line. The newly pattern showed the highest score in the functional test of several actions. It was due to the reduction of the length from waist to crotch as well as the belt width. It made waist-line movement better, and made it easier and more comfortable to sit down. The newly pattern also showed the highest score in the functional test classified by specific movements of parts of the body for the same purpose. The slacks which were made of elastic materials showed better results than the non-elastic ones on external appearances and functional test items. It showed that the elastic materials played a better role in the increase of functional action of abdominally fat, aged women. This study suggests that the newly designed slacks pattern could give abdominally fat, aged women better external features and a more comfortable fitting sensation. As well, the results were significant as basic data to produce ready-made and/or tailer-made garments.

A Cognitive Study on the Usability of Cross-referencing link ad Multiple hierarchies (교차적 연결과 다계층구조의 유용성에 관한 인지적 연구 : 사이버쇼핑몰의 커스터머 인터페이스를 중심으로)

  • 이정원;김진우
    • Korean Journal of Cognitive Science
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    • v.10 no.1
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    • pp.25-43
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    • 1999
  • The focus of this study is on the elements of structure design that facilitate u user interaction with applications within cyberspace Structure design entails decisions regarding the optimal classification and hierarchical organization of information into s successively higher units. i.e .. the grouping of highly related information in the form of nodes of a site and the subsequent connection of nodes that are inter-related. The decisions are based on the designer's subjective classification framework. which is not always compatible with that of the user. We propose that the ensuing cognitive dissonance can be reduced via the employment of multiple hierarchies and cross-referencing links. Multiple hierarchies represent a single information space in terms of a number of single hierarchies. each of which represent a different perspective Cross-referencing refers to the inter-connection between the constituent hierarchies by providing a link to the alternate hierarchy for information that is most likely to be categorized in diverse manners by users with differing perspectives. In this study we conducted two empirical studies to gauge the effectiveness of multiple hierarchies and Cross-referencing links in the domain of cyber shopping malls. In the first phase. an experiment was conducted to determine how subjects classified given products with respect to two different perspectives for categorization. Experimental cyber malls were developed based on the results from the first phase to test the effectiveness of multiple hierarchies and cross-referencing links. Results show that the ease of navigation was higher for cyber malls that had implemented cross-referencing links are of greater value when used in conjunction with single hierarchical designs rather than multiple hierarchies. Users satisfaction with and ease of navigation was higher for cyber malls that had not implemented multiple hierarchies. This paper concludes with discussion of these results and their implications for designers of cyber malls.

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Integrated Eco-Engineering Design for Sustainable Management of Fecal Sludge and Domestic Wastewater

  • Koottatep, Thammarat;Polprasert, Chongrak;Laugesen, Carsten H.
    • Journal of Wetlands Research
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    • v.9 no.1
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    • pp.69-78
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    • 2007
  • Constructed wetlands and other aquatic systems have been successfully used for waste and wastewater treatment in either temperate or tropical regions. To treat waste or wastewater in a sustainable manner, the integrated eco-engineering designs are explained in this paper with 2 case studies: (i) a combination of vertical-flow constructed wetland (CW) with plant irrigation systemfor fecal sludge management and (ii) integrated CW units with landscaping at full-scale application for domestic wastewater treatment. The pilot-scale study of fecal sludge management employed 3 vertical-flow CW units, each with a dimension of $5{\times}5{\times}0.65m$ (width ${\times}$ length ${\times}$ media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/$m^2.yr$ and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80 - 96%. The accumulated sludge layers of about 80 - 90 cm was found at the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation Sunflower plant (Helianthus annuus) plots, each with a dimension of $4.5{\times}4.5m$ ($width{\times}length$). In the study, the CW percolate were fed to the treatment plots at the application rate of 7.5 mm/day but the percolate was mixed with tap water at different ratio of 20%, 80% and 100%. Based on a 1-year data of 3-crop plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increasing in CW percolate ratios. The highest plant biomass yield and oil content of 1,000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower is found. In addition to the pilot-scale and field experiments, a case study of the integrated CW systems for wastewater treatment at Phi Phi Island (a Tsunami-hit area), Krabi province, Thailand is illustrated. The $5,200-m^2$ CW systems on Phi Phi Island are not only for treatment of $400m^3/day$ wastewater from hotels, households or other domestic activities, but also incorporating public consultation in the design processes, resulting in introducing the aesthetic landscaping as well as reusing of the treated effluent for irrigating green areas on the Island.

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Distraction Techniques for Children Undergoing Procedures: A Critical Review of Korean Intervention Research (아동기 처치관련 관심전환요법: 국내 아동 중재연구의 비평적 고찰)

  • Im, Eun Seon;Kim, Jin Sun
    • Child Health Nursing Research
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    • v.20 no.4
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    • pp.340-349
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    • 2014
  • Purpose: The purpose of this study was to provide a critical assessment of evidence-based Korean pediatric research that can inform clinical practicability of, and future research on distraction interventions for pediatric procedural pain management. Methods: A critical review of evidence-based Korean pediatric research was conducted. Databases were searched to identify research that included an evaluation of a distraction intervention as an intervention for pediatric procedural pain management. The search yielded 68 studies. Results: From these studies, 14 were included for this review and all were recently published (2003-2014). Quasi experimental designs were most frequently used (n=12) and for 71.4% the focus was preschoolers. Audiovisual techniques were the most common form of distraction. In most studies clinical utility of the distraction intervention was not examined. Fairly consistent reductions in behavioral measures of pain in association with the distraction intervention were found but less consistent results were found for physiological measures. Conclusion: Lack of methodological rigor limits the evidence for distraction interventions to reduce pain and fear experienced by children during painful procedures. Further research to analyze the cost and time-effectiveness and to identify consumer and provider satisfaction with distraction interventions is needed to determine whether distraction interventions are clinically relevant.

Trends of Doctoral Dissertations of One College of Nursing in Korea (일 간호대학 박사학위논문의 분석을 통한 간호학 연구의 경향)

  • Choe, Myoung-Ae;Hong, Kyung-Ja;Han, Kyung-Ja;Park, Young-Sook;Park, Sung-Ae;Hah, Yang-Sook;Kim, Keum-Soon;Yun, Soon-Nyung;Song, Mi-Soon;Yi, Myung-Sun;Lee, In-Sook;Park, Hyeoun-Ae;ChoiKwon, S-Mi;Chung, Chae-Weon;Park, Yeon-Hwan;Chang, Hee-Kyung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.15 no.1
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    • pp.32-43
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    • 2009
  • Purpose: The purpose of this study was to identify the trend of nursing research by analyzing the doctoral dissertations in one college of nursing in Korea. Method: The areas of research, the methodological characteristics, and theories used in the research were explored in all doctoral dissertations (n=120) published from 1989 to 2006. Result: Mainly "Nursing" has been studied (44.9%) among four meta-paradigms of nursing science. The "client" domain (46.7%) and the "practice" domain (41.7%) were most frequently studied in type of nursing knowledge. The main purpose of the thesis was to develop nursing interventions and examine the effectiveness of the practice (40.8%) in quantitative research. Almost all (94.7%) of the qualitative dissertation studies were to explore phenomena in the nursing field. Almost half of the dissertations (43.9%) were an experimental design, 34.7% were a model construction, and 15.8% were a qualitative design. The majority of dissertations (83.3%) were to apply the specific theory and almost half (43.8%) studied borrowed theories from other fields. Conclusion: It is necessary to develop more rigorous and various research designs such a longitudinal design, or randomized controlled trial and this will lead to expanding the body of nursing knowledge.

Examination of Color Difference in Elastic Pavement that uses EPDM Chip using Ultraviolet Ray Accelerated Weathering Test (자외선 촉진 내후성 시험에 의한 EPDM Chip을 사용한 탄성포장의 색차분석)

  • Hong, Chang Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1D
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    • pp.91-98
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    • 2011
  • Recently, the usage of elastic paving using EPDM Chip instead of pedestrian sidewalk blocks or permeable concrete used mostly for pedestrian walk, trails and in parks has been increassed as it can absorb impact during walking and produce wide range of colors and designs. However, the properties of EPDM Chip including elasticity and durability are decreased when exposed to ultraviolet ray and scenic paving functions through various colors are lowered due to the yellowing phenomenon. In this study, ultraviolet ray accelerated weathering test has been conducted to analyze the color changes in EPDM Chip and polyurethane resin, which are the main ingredients of elastic paving, when exposed to ultraviolet ray. The color differences are quantitatively analyzed through the color value coordination of the colored space by using the color difference scheme. The experimental results show that the color changes in BL polyurethane resin which is used most frequently at present was larger than that of EPDM Chip. Moreover, the total color difference, ${\Delta}E$, of BC polyurethane resin are 3.162 on the $14^{th}$ day of commencement of acceleration, which is 6 times greater color change resistance against ultraviolet ray than that of BL polyurethane resin with total color difference of 20.639. Therefore, the usage of BC polyurethane resin, which is manufactured to have chain-type molecular structure by using the isocyanate as the HMDI at the time of producing polymer, as binder in elastic paving with EPDM Chip is found to be a highly efficient method of restraining the color changes due to the ultraviolet ray.

Crossed Effects of Light and Temperature on the Growth and Maturation of Gametophytes in Costaria costata and Undaria pinnatifida (쇠미역(Costaria costata)과 미역(Undaria pinnatifida) 배우체의 생장과 성숙에 광과 온도가 미치는 영향)

  • Na, Yeon Ju;Jeon, Da Vine;Han, Su Jin;Maranguy, Cyr Abel Ogandaga;An, Dae Sung;Cha, Hyung Kee;Lee, Jae Bong;Yang, Jae Hyeong;Lee, Hae Won;Choi, Han Gil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.2
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    • pp.190-197
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    • 2016
  • We examined for differences in the growth and fertility of microscopic stages between Costaria costata and Undaria pinnatifida in crossed temperature×irradiance (12, 17, 22℃×20, 60 μmol photons m–2s–1) and daylength×irradiance (8, 12, 16, 24 h×20, 60 μmol photons m–2s–1) experimental designs. After 13 days in culture, maximum gametophyte growths of the two species were obtained under the following combinations of factors: 17℃×60 μmol photons m–2s–1 and 24 h daylength×60 μmol photons m–2s–1. C. costata gametophytes produced sporophytes about 6 days earlier than those of U. pinnatifida. Sporophyte densities were highest in the 12 h daylength×60 μmol photons m–2s–1 combination after 20 days in C. costata (9.7 plants mm–2) and 26 days in U. pinnatifida (9.1 plants mm–2). However, optimal growth conditions for the microscopic sporophytes differed between species: 17℃×60 μmol photons m–2 s–1 for C. costata, 12℃×60 μmol photons m–2 s–1 for U. pinnatifida. Thus, C. costata gametophytes grew faster and produced sporophytes earlier than those of U. pinnatifida, even though the haploid gametophytes of the two species responded similarly to environmental conditions. Optimal growth temperatures for the microscopic sporophytes also differed between species.

A VLSI Design of High Performance H.264 CAVLC Decoder Using Pipeline Stage Optimization (파이프라인 최적화를 통한 고성능 H.264 CAVLC 복호기의 VLSI 설계)

  • Lee, Byung-Yup;Ryoo, Kwang-Ki
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.12
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    • pp.50-57
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    • 2009
  • This paper proposes a VLSI architecture of CAVLC hardware decoder which is a tool eliminating statistical redundancy in H.264/AVC video compression. The previous CAVLC hardware decoder used four stages to decode five code symbols. The previous CAVLC hardware architectures decreased decoding performance because there was an unnecessary idle cycle in between state transitions. Likewise, the computation of valid bit length includes an unnecessary idle cycle. This paper proposes hardware architecture to eliminate the idle cycle efficiently. Two methods are applied to the architecture. One is a method which eliminates an unnecessary things of buffers storing decoded codes and then makes efficient pipeline architecture. The other one is a shifter control to simplify operations and controls in the process of calculating valid bit length. The experimental result shows that the proposed architecture needs only 89 cycle in average for one macroblock decoding. This architecture improves the performance by about 29% than previous designs. The synthesis result shows that the design achieves the maximum operating frequency at 140Mhz and the hardware cost is about 11.5K under a 0.18um CMOS process. Comparing with the previous design, it can achieve low-power operation because this design is implemented with high throughputs and low gate count.