• Title/Summary/Keyword: Engineering Practice

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Selection of Appropiate Plant Species of VFS (Vegetative Filter Strip) for Reducing NPS Pollution of Uplands (밭 비점오염저감을 위한 초생대 적정 초종 선정)

  • Choi, Kyung-Sook;Jang, Jeong-Ryeol
    • Journal of Korea Water Resources Association
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    • v.47 no.10
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    • pp.973-983
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    • 2014
  • This study focused on the selection of appropriate plant species of VFS (vegetative fiter strips) and the assessment of VFS effects for reducing NPS (non-point source) pollution from uplands. The experimental field was constructed with 1 control and 6 treated plots in the upland area of $1,500m^2$ with 5% slope which is located in Gunwi-gun, Gyeongbuk province. Six vegetation including Chufa, Common crabgrass, Barnyard grass, Turf grass, Tall fescue, Kenturky bluegrass, were applied to install VFS systems during the study period from June 2011 to Dec. 2012. The results of this study showed that 6.1~77.8% in runoff and 15.6~90.3% in TS, 49.9~96.6% in T-P, and 6.7~91.1% in T-N were reduced from the VFS treated plots. Generally high reduction effects were observed from TS, T-P, T-N, and SS, while BOD, TOC, and $NO_3^-$ showed low reductions. The best vegetation type was Turf grass showing higher reduction effects of NPS pollutions and having relatively easier maintenance efforts compared to other vegetations selected in this study. Based on these results, VFS technique found to be an effective management practice for reducing agricultural NPS pollutions in Korean upland conditions. Further study needs to be performed through various field experiments with long term monitoring in order to develop a design manual of VFS system for practical applications.

Development of Supportive Device Design for Artificial Hand Based on Virtual Simulation (가상 시뮬레이션을 이용한 의수 보조 장치 디자인 개발)

  • Lee, Ji-Won;Han, Ji-Young;Na, Dong-Kyu;Nah, Ken
    • Journal of Digital Convergence
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    • v.15 no.10
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    • pp.455-465
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    • 2017
  • This study focuses on design development and verification through virtual simulation based on 3D model data in the cloud platform as a method of utilization of engineering technology of design in the fourth industrial revolution era. The goal of research is to develop and examine a design for the needs of the target that has never been met before through virtual simulations that can be conducted in practice. As a research method, we analyzed secondary data to identify the needs of the target, and did literature research for the ergonomic data and target body development stages. In addition, the design development process of this study was shown meaningful result in design, structure, safety, material, durability through loop test of 7 virtual simulations. This study can be applied to the automated process system based on 3D model data in the 4th industrial revolution era and can be used as an element of the cyber physics system for the additional research.

$\sqrt{s}$- Observational Procedure for Consolidation Analysis (압밀해석을 위한 $\sqrt{s}$- 예측기법)

  • 정성교;최호광
    • Geotechnical Engineering
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    • v.14 no.2
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    • pp.41-54
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    • 1998
  • Predictions of consolidation settlement and time must be always erroneous because of heterogeneity of soil media. errors associated with the measurement of soil parameters, drawback of consolidation theories and so on. When filling is done on compressible soils, the observational procedure is a useful means in practice of evaluating the final consolidation settlement and time. However, the existing observational procedures including some disadvantages such as the difficulty of ending the linearity in the settlement curves, the unavoidable personal error, and so on. A new observational procedure($\sqrt{s}$ method) is suggested here for the consolidation analysis in field. As the results of applying the $\sqrt{s}$ method with other methods to two field data. the fecal settlements predicted by the s method as well as by the Asaoka'$\sqrt{s}$ method agreed well with the measured values. However, results obtained from the hyperbolic method(Tan, 1991) were always overestimated. and there happened many cases not to be predicted by the Hoshino's method. In the settlement curve from the $\sqrt{s}$method, the linearity between 60 and 90 eye of the average degree of consolidation is shown. and then the possibility of a personal error seems to be unusual. The final consolidation times(at $U_{95}$) predicted by the $\sqrt{s}$ method agreed well with the measured ones. but the ones by Asaoka and Tan(1996) methods were very much underestimated or overestimated. where $U_{95}$, is the average degree of consolidation of 95%. The big errors of these two methods seem to result from unconsidering the effect of stage construction.

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Numerical Analysis of Self-Supported Earth Retaining Wall with Stabilizing Piles (2열 자립식 흙막이 공법의 거동특성에 관한 수치해석적 연구)

  • Sim, Jae-Uk;Jeong, Sang-Seom;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.31 no.5
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    • pp.35-46
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    • 2015
  • In this study, the behavior of self-supported earth retaining wall with stabilizing piles was investigated by using a numerical study and field tests in urban excavations. This earth retaining wall can provide stable support against lateral earth pressures through its use of stabilizing piles that provide passive resistance to lateral earth pressures arising due to ground excavations. Field tests at two sites were performed to verify the performance of instrumented retaining wall with stabilizing piles. Furthermore, detailed 3D numerical analyses were conducted to provide insight into the in situ wall behavior. The 3D numerical methodology in the present study represents the behavior of the self-supported earth retaining wall with stabilizing piles. A number of 3D numerical analyses were carried out on the self-supported earth retaining wall with stabilizing piles to assess the results stemming from wide variations of influencing parameters such as the soil condition, the pile spacing, the distance between the front pile and the rear pile, and the pile embedded depth. Based on the results of the parametric study, the maximum horizontal displacement and the maximum bending moment significantly decreased when the retaining wall with stabilizing piles is used. Moreover, the horizontal displacement reduction effect of influencing parameters such as the pile spacing and the distance between the front pile and the rear pile is more sensitive in sandy soil, with a higher friction angle compared to clayey soil. In engineering practice, reducing the pile spacing and increasing the distance between the front pile and the rear pile can effectively improve the stability of the self-supported earth retaining wall with stabilizing piles.

Merits and Demerits of Analytical Marxism Searching for Solutions to the Political Economy of Media/Communication Industry (분석적 마르크시즘의 공과(功過) ‘마르크스주의 경제학’과 ‘신고전파 경제학’의 방법론 논쟁을 통한 미디어/커뮤니케이션 정치경제학의 방향 찾기)

  • Lee, Sang-Khee
    • Korean journal of communication and information
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    • v.45
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    • pp.7-48
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    • 2009
  • The recent crises of Marxism do not mean Marx’s crisis. Marx said that he was not a Marxist. The purposes of this essay explore (1) the modern identity of the political economy; (2) the possibilities of mutual understanding between neoclassical economics and Marxist economics; (3) problems of the political economy in media and communication industry. I have begged for analytical Marxists, because of their good fruits. They accepted the methods of modern social science and they constituted a tremendous advance in the application of the scientific methods to the study of society. In insisting on micro-foundations(methodological individualism), analytical Marxism distinguished itself from structuralism and functionalism. I appreciate that analytical Marxism has reduced a theory to practice. But the works didn’t listen to everyone(from Marxists to un-Marxists), and explain everything. Making theory with production/consumption, macro/micro, and structure/behavior is a road to the political economy in the long run. It also applies to media and communication industry. The realm of media/communication is broad, which in philosophy, humanities, politics, economics, sociology, and engineering. And media policy is more complicated by politicians who look at the same situation from different angles. By the aid of interdisciplinary research, the political economy of media/communication shall explain at full length.

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The efficiency Analysis of study using brainwave measurement device (Biopac 뇌파측정 장치를 이용한 학습의 효율성 분석)

  • An, Young-Jun;Lee, Chung-Heon;Park, Mun-Kyu;Ji, Hoon;Lee, Dong-Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.951-953
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    • 2015
  • Learning for thinking says the behavior of the organism changes as a result of practice or experience. It is very difficult to identify focusing ability objectively when students study. But, brain of the body is not so. EEG signal means continuously electric records of brain potential variation between two points on the scalp when brain activities take place. In types of EEG, there are delta(0~4Hz), theta(4~8Hz), alpha(8~13Hz), beta(13~30Hz) and gamma waves(30~50Hz). SMR waves and Mid-beta waves appear when focused for studying. Part for the most influence on concentrating reported that Mid-beta waves. In relation to brain activities, EEG has been actively researched for evaluating brain focus index system during learning and study. So, By using Biopac system for this study, measured brain wave was converted into FFT for extracting Mid-beta domain signals that are related to learning after giving focus invoked subjects to a small number of people. When concentrating, we measured the change in the power of the Mid-beta frequency domain and presented a correlation. Based on these results, we analyzed whether students are concentrated objectively on learning or not. and hope to offer more efficient learning method.

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The Effectiveness of Sensory Integrative Intervention: A Systematic Review (감각통합중재 효과에 관한 체계적 고찰)

  • Kim, Kyeong-Mi
    • The Journal of Korean Academy of Sensory Integration
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    • v.7 no.2
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    • pp.77-90
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    • 2009
  • Objective : The purpose of this study was to provide evidence for the effectiveness of Sensory Integrative Intervention (SII) through a systematic review. Method : The systematic review was executed using MEDLINE/PubMed, PsycINFO, CINAHL, Cochrane Library, OTSeeker. The key words for search was "effects of sensory integration", "sensory integration therapy", and "sensory integration intervention". 11 studies were used for data analysis, and the level of evidence were level I, leve lII and level IV. The substances of review were subject (population), method (intervention type), effect of the intervention, outcome parameter, and outcome measurement. Results : 1. The subjects of SII were autism spectrum disorders (30.7%), pervasive developmental disorder (15.4%) and preterm infants (15.4%). 2. Most frequently used method was the traditional intervention of J. Ayres (36.5%). The outcome parameters of SII were behavioral outcome (40.63%), motor performance outcome (28.13%), sensory-based outcome (25.0%), and academic outcome (6.35%). 3. The effects of SII were improvement of motor performance (66.7%), sensory-based (62.5%), and behavior problems (61.5%). In most studies, however, academic skill such as writing skill was not a positive outcome parameter in terms of effectiveness of SII. Conclusions : The results implied that the sensory integrative intervention is effective on motor performance, sensory-based and behavioral change, but not on the academic skill. It is suggested that the future research need to be done to examine whether and how the effect of sensory integration intervention can be long-lasting and contribute any academic skill and activities of daily living performance.

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Effects of incorporation of 2.5 and 5 wt% TiO2 nanotubes on fracture toughness, flexural strength, and microhardness of denture base poly methyl methacrylate (PMMA)

  • Naji, Sahar Abdulrazzaq;Behroozibakhsh, Marjan;Kashi, Tahereh Sadat Jafarzadeh;Eslami, Hossein;Masaeli, Reza;Mahgoli, Hosseinali;Tahriri, Mohammadreza;Lahiji, Mehrsima Ghavvami;Rakhshan, Vahid
    • The Journal of Advanced Prosthodontics
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    • v.10 no.2
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    • pp.113-121
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    • 2018
  • PURPOSE. The aim of this preliminary study was to investigate, for the first time, the effects of addition of titania nanotubes ($n-TiO_2$) to poly methyl methacrylate (PMMA) on mechanical properties of PMMA denture base. MATERIALS AND METHODS. $TiO_2$ nanotubes were prepared using alkaline hydrothermal process. Obtained nanotubes were assessed using FESEM-EDX, XRD, and FT-IR. For 3 experiments of this study (fracture toughness, three-point bending flexural strength, and Vickers microhardness), 135 specimens were prepared according to ISO 20795-1:2013 (n of each experiment=45). For each experiment, PMMA was mixed with 0% (control), 2.5 wt%, and 5 wt% nanotubes. From each $TiO_2$:PMMA ratio, 15 specimens were fabricated for each experiment. Effects of $n-TiO_2$ addition on 3 mechanical properties were assessed using Pearson, ANOVA, and Tukey tests. RESULTS. SEM images of $n-TiO_2$ exhibited the presence of elongated tubular structures. The XRD pattern of synthesized $n-TiO_2$ represented the anatase crystal phase of $TiO_2$. Moderate to very strong significant positive correlations were observed between the concentration of $n-TiO_2$ and each of the 3 physicomechanical properties of PMMA (Pearson's P value ${\leq}.001$, correlation coefficient ranging between 0.5 and 0.9). Flexural strength and hardness values of specimens modified with both 2.5 and 5 wt% $n-TiO_2$ were significantly higher than those of control ($P{\leq}.001$). Fracture toughness of samples reinforced with 5 wt% $n-TiO_2$ (but not those of 2.5% $n-TiO_2$) was higher than control (P=.002). CONCLUSION. Titania nanotubes were successfully introduced for the first time as a means of enhancing the hardness, flexural strength, and fracture toughness of denture base PMMA.

The Current Status and Educational Requirements for Genetics Curriculum at Nursing Institutions (간호교육에서의 유전학 교육과정 현황과 요구)

  • Hong, Hae-Sook;Byeon, Young-Soon;Na, Yeon-Kyung
    • Journal of Korean Biological Nursing Science
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    • v.5 no.1
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    • pp.13-22
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    • 2003
  • The purpose of this study was to investigate and analyze current educational requirements related to genetics curriculum(from June 2002 to September 2002) established at nursing institutions and to provide the basic data for the development of genetics science program at the undergraduate. Subjects of this study were comprised of twenty-three colleges of nursing in 4-year baccalaureate and thirty colleges in 3-year diploma programs. The results of this study were as follows : 1) 32 colleges offer courses related to genetics. 29 among 32 colleges have that integrated. Three schools have established completely independent courses of genetics. 21 colleges do not have any courses dealing with genetics. 2) The contents of courses related to genetics include: Congenital abnormalities, chromosomal aberrations, congenital metabolic disease, prenatal diagnosis and genetic counseling, genes and chromosomes, immune genetics, blood type and genetics, rule of genetics, variation in gene expression, the map of the human gene, gene linkage genetics, interaction of genes, single inheritance in order and genetic biochemistry. 3) For course credit, 14colleges(48.3%) offered at most 1 credit per course. The grade of student who can take the course, 51.7% were in their second year while 37.9% were in their third year. The majors of nursing faculty who taught the course were nursing(51.7%) and basic nursing science(17.2%). 4) As far as the need of opening the courses related to genetics, 36 colleges(67.0%) have made a 'need', 12 schools(22.6%) state 'dose not need'. 711e reason for need were the following development of bio engineering, increase number of patients who are related to genetics, recognition of the need in clinical nursing. 7 schools(13.2%) agreed to offer independent course in genetics but 39 schools(73.6%) are in disagreement with that. When the school offers the course with other courses, 27 schools(50.0%) are opening basic nursing science and 14 schools(26.4%) are opening nursing as an integrated courses. If the name of course was either genetic nursing(34.0%) or genetics(28.3%), the credits for the course was one or 2 credits. 33 schools(62.3%) students were in the first or second years. 41 schools(84.9%), the majors of the faculty who had taught the course were either basic nursing science(35.8%), nursing(28.3%) or basic medicine(24.5%). The contents of the course should include in that order: Chromosome aberrations, prenatal diagnosis and genetic counseling, congenital metabolic disease, congenital abnormalities, genes and chromosomes, the rules of genetics, immune genetics, interaction of genes, variation in gene expression, etc. The results and discussions of the study indicate that the entire curriculums need to be investigated with respect to contents of education, nursing curriculums and name of courses because of the increasing need of knowledge related to genetics in the clinical practice.

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A Study on the Core Management Competencies of Ventures Formed by Entrepreneur's Incubator Organizations and Startup Experience: Focusing on the Biomedical Industry in Korea (창업가의 배태조직과 창업경험이 형성하는 창업기업의 핵심경영자원에 관한 연구: 한국의 바이오메디컬 산업을 중심으로)

  • Kim, Doyeon;Kim, Yeonbae;Song, Changhyeon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.1
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    • pp.269-284
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    • 2020
  • This study explored the core management competencies of ventures formed by the entrepreneur's incubator organization and startup experience in the biomedical industry in Korea. An in-depth interview was conducted with 13 entrepreneurs of biomedical ventures. Based on the previous literature, the core management competencies of the ventures, which are influenced by the incubator organization and startup experience, are classified into 'technical competency', 'organization management competency', 'network competency' and 'market pioneering competency'. Analysis of the in-depth interview has revealed 18 factors influencing the formation of the core management competencies of ventures. Qualitative factors that were not addressed by the previous empirical studies were identified in this study. These include 'confidence in technology development', 'way of performing R&D', 'organizational culture' etc. This study is characterized by its scarcity as a qualitative study that deals with the entrepreneurs' prior experience. In addition, this study categorize the core management competencies which are formed by entrepreneurs' incubator organization and startup experience as four factors. This result is expected to be useful in future research.