• Title/Summary/Keyword: repetition

Search Result 1,575, Processing Time 0.032 seconds

Numerical Model Updating Based on Univariate Search Method for High Speed Railway Bridges (단변분 탐색법에 기초한 고속철도교량의 수치해석 모델 개선)

  • Park, Dong-Uk;Kim, Nam-Sik;Kim, Sung-Il
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.34 no.1
    • /
    • pp.17-27
    • /
    • 2014
  • Numerical model became one of most important tools for identifying the state of an existing structure in accordance with development of numerical analysis techniques. A numerical model should be updated based on the measured responses from the existing structure to accurately use the model for identifying the state of the bridge and executing numerical experiments. In this study, a new model updating method based on repetition method without a differential function is introduced and applicability for high speed railway bridge is verified with dynamic stability analysis. A fine measurement based on measurement points roaming method was executed with an wireless measurement system for precise dynamic characteristic analysis. The natural frequencies and mode shapes were estimated by correlation analysis and a mode decomposition technique. An initial numerical model was constructed based on design drawings and the model have been updated in accordance with the introduced model updating method. The results from numerical experiment and field test have been compared for verifying the applicability of the model updating method. And the dynamic stability analysis has been executed to verify the usability of the updated numerical model and the model updating method. It seems that the model updating method can be used for various bridges after evaluation of applicability for other type bridges in further studies.

Improvement of Fourier Transform Arteriography by Use of Ramped RF Profile and Dual Projections (경사 윤곽의 고주파 펄스와 이중 투사법에 의한 Fourier 변환 동맥 혈관 촬영법의 성능 향상)

  • Jung, K. J.;Kim, I. Y.;Lee, M. W.;Yi, Y.
    • Investigative Magnetic Resonance Imaging
    • /
    • v.6 no.1
    • /
    • pp.41-46
    • /
    • 2002
  • The Fourier transform arteriography (FTA) exploits the periodic variation of arterial flow velociety of arterial flow velocity in stnchronized with cardiac cycles. This technique is intrinsically unique compared to other modern techniques. This technique separates the arteries from the veins using the pulsatile arterial flow without using the presaturation RF pulses. Therefore, it has less RF deposition and is free from the dark band artifacts that can arise from retrograde flow and curved arteries. Furthermore, it is free from the artifacts induced by eddy currents. However, there are some drawbacks such as a single projection view and the saturation of arteries at the end of an imaging slab. These drawbacks are circumvented by applying recently developed techniques. The fast gradient switching capability of modern MRI systems enabled us to incorporate dual projection views into the conventional FTA sequence without increasing the repetition time. In addition, signals from the distal arteries were enhanced by use of a ramped RF pulse and therefore the distal arteries were less saturated. By use of the FTA sequence with dual projection views and the ramped RF pulse, we acquired the sagittal and coronal projection views of femoral arteriograms simultaneously with more enhanced signals of distal arteries than the conventional FTA.

  • PDF

Anthracofibrosis Mimicking Lung Cancer on CT: MR Imaging Findings (CT상 폐암과 유사하게 보이는 기관지 탄분 섬유화증의 자기공명영상 소견)

  • 류대식;이덕희;정승문;최수정;박성빈;박만수;강길현
    • Investigative Magnetic Resonance Imaging
    • /
    • v.5 no.1
    • /
    • pp.18-23
    • /
    • 2001
  • Purpose : To describe the MRI findings in the bronchial anthracofibrosis mimicking lung cancer on CT examination. Materials and methods : Ten patients, who showed CT findings mimicking lung cancer, were selected among fifty patients of bronchial anthracofibrosis proven by bronchoscopic biopsy, consisting of two men and eight women, ranging in age from 58 to 79 years old faverage age, 68 years old). CT scan and MRI were performed in all patients (n=10). Percutaneous lung biopsy on mass was performed in one patient. MRI findings were analyzed with the emphasis on the signal intensity of the mass (n=4), collapsed lung (n=4) and Iymph node (n=10) on axial T1 and T2-weighted images by two radiologists in consensus. No contrast enhancement was used in all cases. Results : CT scan revealed mass (n=4), atelectasis with obstructive pneumonia(n=4) and bronchial wall thickening(n=2). All patients showed enlarged medistinal Iymph nodes(n=10). The mass showed low signal intensity on T1WI and T2WI (n =4). The collapsed lung in patients with atelectasis indicated intermediate signal intensity on T1WI and low signal intensity on T2WI (n= 4). Nine patients showed low sisnal intensity of Iymph node on T1WI and T2WI, except one patient who showed central high signal intensity with peripheral rim of low signal intensity in right lower paratracheal llmph node on T2WI. Conclusion : Low signal intensity of a mass, collapsed lung, and lymph nodes on T2WI in anthracofibrosis patients may be helpful in differentiation of the lesion from lung cancer.

  • PDF

Minimalism in Modern Hairstyle and Fashion (현대 헤어스타일과 의상에 나타난 미니멀리즘의 양상)

  • Sohn Hyang-Mi;Park Kil-Soon
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.29 no.12 s.148
    • /
    • pp.1554-1561
    • /
    • 2005
  • This study aims to analyze modern hairstyle and fashion in the collections in the late 1990s, based on the concepts and characteristics of Minimalism, a buzzword of the art field in the 1960s. This study used qualitative research method, in other words, presenting an analysis framework by studying domestic and foreign books and dissertations on Minimalism and then applying the Internet or visual image to the analysis framework. The result indicates that Minimalism design in modem hairstyle and fashion has four characteristics: simplicity, unity, repetition and spatiality.

Reflections on the Elementary School Geometry Curriculum in the Netherlands -Based on the Realistic Mathematics Education- (네덜란드의 초등학교 기하 교육과정에 대한 개관 -현실적 수학교육을 중심으로-)

  • Chong, Yeong-Ok
    • School Mathematics
    • /
    • v.9 no.2
    • /
    • pp.197-222
    • /
    • 2007
  • The study aims to reflect the elementary school geometry education based on the Realistic Mathematics Education in the Netherlands in the light of the results from recent researches in geometry education and the direction of geometry standards for school mathematics of the National Council of Teachers of Mathematics in order to induce implications for improving korean geometry curriculum and textbook series. In order to attain these purposes, the present paper reflects the history of elementary school geometry education in the Netherlands, sketches the elementary school geometry education based on the Realistic Mathematics Education in the Netherlands by reflecting general goals of the mathematics education, the core goals for geometry strand of the Netherlands, and geometry and spatial orientation strand of Dutch Pluspunt textbook series for the elementary school more concretely. Under these reflections on the documents, it is analyzed what is the characteristics of geometry strand in the Netherlands as follows: emphasis on realistic spatial phenomenon, intuitive and informal approach, progressive approach from intuitive activity to spatial reasoning, intertwinement of mathematics strands and other disciplines, emphasis on interaction of the students, cyclical repetition of experiencing phase, explaining phases, and connecting phase. Finally, discussing points for improving our elementary school geometry curriculum and textbook series development are described as follows: introducing spatial orientation and emphasizing spatial visualization and spatial reasoning with respect to the instruction contents, considering balancing between approach stressing on grasping space and approach stressing on logical structure of geometry, intuitive approach, and integrating mathematics strands and other disciplines with respect to the instruction method.

  • PDF

A Study on Characteristics of Core Projects Described in 3rd Community Health Plans (제3기 지역보건의료계획서에 기술된 핵심사업의 특성에 관한 연구)

  • Kim, Dong-Moon;Lee, Weon-Young;Moon, Ok-Ryun;Kim, Chang-Yup
    • Journal of Preventive Medicine and Public Health
    • /
    • v.37 no.1
    • /
    • pp.88-98
    • /
    • 2004
  • Objectives : The 3rd community health plan let health centers select and promote core projects considering budget and manpower. This study analyzed the content and selection processes of core projects, using the nationwide 3rd community health plans, to give relevant information on health center policies. Methods : Classification criteria for content analysis of core projects were established and verified through a literature review and by specialist discussions. Fifty plans were selected by stratified proportional random sampling for regional characteristics. And coding criteria standardized through coding repetition and discussion, by 2 persons (k>0.7). Using stratified proportional random sampling for 16 cities and provinces, regional characteristics, 117 plans were selected, and the contents of the core project selection processes and program contents analyzed. Results : The survey was used by 59.8 % of samples as a core project decision-making method. The partici- pants included 98.6, 81.4, 40 and 38.6% of the health staffs, residents, medical institutions, and administrators, respectively. Discussion was used by 15.4% of samples. The participants were health staffs by 100% as a great. The ranking of the frequencies of the selected core projects were, in order; chronic disease control, health promotion, elderly health, maternal-child health, and oral health at 16.4, 14.8, 14.3, 12.7 and 11.9%, respectively. Analyses on the chronic disease control and elderly health contents showed the diversity of object disease, high rates of visitors on patient detection programs, high rates of unclear target populations, and the provision of medical exams and treatments as the main services, with high variations in business per-formance. The national health budgets for health centers in 2003 were about 910 and 240 million won for chronic disease control and elderly health, respectively, which were less than for the other five priority core projects. Conclusions : The chronic disease control and elderly health at the health centers were not standardized for object disease, patient detection program, target population, service provision, and national support budget was insufficient. Thus it is necessary to develop standard guidelines, and increase financial support, for chronic disease control and elderly health

An Exploratory Analysis School-based Intervention Studies to Prevent Smoking by American Adolescents (미국의 청소년 흡연예방을 위한 중재 프로그램의 현황)

  • Jung, Hye-Sun;Ha, Yeong-Mi;Jhang, Won-Gi;Lee, Ji-Won;Yi, Yun-Jeong;Yun, Soon-Nyung
    • Journal of the Korean Society of School Health
    • /
    • v.21 no.2
    • /
    • pp.119-134
    • /
    • 2008
  • Purpose: The purpose of this study is to understand a variety of intervention studies to prevent smoking by adolescents in U.S. and find out implications for Korea. Methods: This study reviewed articles found in the internet and analysed the data of US DHHS and CDC. Results: The School Health Policies and Programs Study (SHPPS) is a national survey periodically conducted to assess school health policies and programs of U.S. The main components of SHPPS are health education and physical education, health services, mental health and social services, school policies, and school environments. The CDC guidelines for school health programs to prevent tobacco use and addiction are composed of policy, instruction, curriculum, training, family involvement, tobacco-use cessation efforts, and evaluation. School-based interventions to prevent smoking can be classified into the categories of information-giving curricula, social competence curricula, social influence approaches, combined methods draw on social competence and social influence approaches and multi-modal programmes and Youth Empowerment study. The key programs for adolescent smoking prevention are ALERT Project, HSPP, TNT Project, MPP, NC YES. Conclusions: As smoking is often the first step of unhealthy behaviour such as alcohol drinking, illegal drugs, and violence, smoking prevention programmes for adolescents in U.S. have been comprehensive school-based health programs. In smoking prevention programs for adolescents, CDC plays a critical role by supporting survey, research, policy, and funds. The effectiveness of the programs was high when it was based on school and involved parents, community, and mass media. As the effect of each programme is not expected to last for a long time, consistent repetition of these interventions is essential. Current smoking prevention programs for adolescents are exploring the empowerment approach focused on the active involvement of participants rather than traditional approaches using order and discipline.

Operatonal characteristics of the PLS linac vacuum system (PLS 선형가속기 진공계의 운전특성)

  • 김임경;박용정;김경렬;남궁원
    • Journal of the Korean Vacuum Society
    • /
    • v.5 no.4
    • /
    • pp.269-277
    • /
    • 1996
  • The vacuum systems of PLS linac provides average pressure of $2.6\times 10^{-6}$Pa under high power microwave of 54 MW peak with 4.1 $\mu \textrm s$ pulse width and 10 Hz repetition rates. The base pressure of system is$2.4\times 10^{-6}$Pa with 45$^{\circ}C$ cooling water. The outgassing rate of the system is decreased from $3.0\times 10^{-11}Torr-l/sec-\textrm{cm}^2$ at the initial stage after installation to $1\times 10^{-12}Torr-l/sec-\textrm{cm}^2$ at present. Total accumulated microwave energy dose is about 140 GJ per module. All ion pumps are working under saturated regime and effective pumping speeds of 60 I/s, 230 I/s ion pumps are 45 I/s, 65 I/s, 140 I/s under the operating range. Main problems occurred in recent year are troubles of ion pump controller and vacuum gauge controller, vacuum leak of energy doubler window and electron gun ceramic, and water leak in the dummy load of acceleraing columns. Total of 41 troubles with 140. 8 hours down time give good system availability of 98%. Down time can be reduced by high power waveguide valves and water dummy loads under development, and then availability is expected to be increased up to 99.5%.

  • PDF

Interactivity and Rhizomatic Art Systems: Focusing on the Digital Images (상호작용성(Interactivity)과 리좀(Rhizome)적 작품체계: 디지털 이미지를 중심으로)

  • Park, Yeon-Sook
    • The Journal of Art Theory & Practice
    • /
    • no.9
    • /
    • pp.33-57
    • /
    • 2010
  • Focused on the performance of interactivity in the appreciation of media art, this study is associated with the continually changed art texts and a participator's physical reactions to savor the art. Digital works of art emphasizing interactivity usually decentralize and disperse the responsibility and the central role for creating and producing the art works. Proper procedure of the work is generated by actions such as clicking the mouse, controlling the joy stick or actual movement of anticipators' bodies. The art works are influenced by participators' interactivity, which makes the leading roles and the responsibility for creating art scattered and divided. These features are similar with those of the 'Rhizome' which Gilles Deleuze(1925~1995) and Felix Guattari(1930~1992) have discussed. In their argument, 'Rhizome' is an interval or being 'between', which keeps changing. 'Rhizome' is a state in which the individual and the work of art never reach the conclusion, only a phenomenon of eternally altering. Like 'Rhizome', this sort of art work has the decentralized system, opens for several directions, and activates the system which is changeable as linked items increased or decreased. These works stimulate the individual to perform and act while appreciating the art piece. In terms of processing and preceeding, interactivity is the important equipment and catalyzer. Through these procedures, the pieces can be the 'floating work of art' combined and condensed with the whole participators' reactions. The 'floating work of art' is neither the expression of an individual nor that of one particular group. Multidimensional influence of the web is the web which is constantly reorganizing and producing in its connective state. This connective state is activated by interactivity. The Rhizomatic system embodies the floating work of art process. Due to each individual perceiving art in individualistic terms, there is no dominating powers or central points. I regard this art works possessing above traits as the work of art with Rhizomatic system. The work of art with the Rhizomatic system is embodied through interactivity and because physical action activates the process of appreciation, a participator can actually experience and practice the philosophy. Ultimately the Rhizomatic speculation occurs during the interactivity of appreciating the Rhizomatic art pieces. The Rhizomatic system penetrates into the intuitive area beyond our recognition and thoughts, as we are engaged in the connective process. With the methods and manners of interactive art, we can possibly reconsider the system as a tool in which the participator is directly able to link experience and theory to the philosophies of Deleuze and Guattari.

  • PDF

Effects of Infrared Pasteurization on Quality of Red Pepper Powder (적외선 살균이 고춧가루의 품질에 미치는 영향)

  • Jung, Jin-Joo;Choi, Eun-Ju;Lee, You-Jin;Kang, Sung-Tae
    • Korean Journal of Food Science and Technology
    • /
    • v.43 no.2
    • /
    • pp.156-160
    • /
    • 2011
  • A tray type-infrared (IR) pasteurization system was developed for decreasing microorganisms in red pepper powder (RPP). The RPP was passed through a tray by a vibrating mode under the 4 IR lamps (total 8000 W) and by circulating water under the tray. Fungi was pasteurized by applying power higher than 2000 W to the RPP. The decrease in viable cell numbers of bacteria, however, was not observed under the same conditions. Conveying speed of RPP was optimized to 106-164 g/min on the basis of microbial reduction and retaining of moisture content of RPP. The water content of 32 mesh-RPP decreased rapidly after pasteurization. However, fungi in both RPPs could be sterilized regardless of particle sizes. The repetition of IR pasteurization was not favourable due to severe decrease of water content in RPP. The IR pasteurization of RPP did not cause significant difference in the capsaicinoid contents, ASTA colour value, and L, a, and b values under all investigated conditions.