• Title/Summary/Keyword: Push-Pull

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Art and Collectivity (미술과 집단성)

  • Kwok, Kian-Chow
    • The Journal of Art Theory & Practice
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    • no.4
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    • pp.181-202
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    • 2006
  • "When it comes to art, nationalism is a goodticket to ride with", says the title of a report in the Indian Express (Mumbai, 29 Oct 2000). The newspaper report goes on to say that since Indian art was kept "ethnic" by colonialism, national liberation meant opening up to the world on India's own terms. Advocacy, at the tail end of the 20th century, would contrast dramatically with the call by Rabindranath Tagore, the founder of the academy at Santiniketan in 1901, to guard against the fetish of nationalism. "The colourless vagueness of cosmopolitanism," Tagore pronounced, "nor thefierce self-idolatry of nation-worship, is the goal of human history" (Nationalism, 1917). This contrast is significant on two counts. First is the positive aspect of "nation" as a frame in art production or circulation, at the current point of globalization when massive expansion of cultural consumers may be realized through prevailing communication networks and technology. The organization of the information market, most vividly demonstrated through the recent FIFA World Cup when one out of every five living human beings on earth watched the finals, is predicated on nations as categories. An extension of the Indian Express argument would be that tagging of artworks along the category of nation would help ensure greatest reception, and would in turn open up the reified category of "art," so as to consider new impetus from aesthetic traditions from all parts of the world many of which hereto fore regarded as "ethnic," so as to liberate art from any hegemony of "international standards." Secondly, the critique of nationalism points to a transnational civic sphere, be it Tagore's notion of people-not-nation, or the much mo re recent "transnational constellation" of Jurgen Habermas (2001), a vision for the European Union w here civil sphere beyond confines of nation opens up new possibilities, and may serve as a model for a liberated sphere on global scale. There are other levels of collectivity which art may address, for instance the Indonesian example of local communities headed by Ketua Rukun Tetangga, the neighbourhood headmen, in which community matters of culture and the arts are organically woven into the communal fabric. Art and collectivity at the national-transnational level yield a contrasting situation of, on the idealized end, the dual inputs of local culture and tradition through "nation" as necessary frame, and the concurrent development of a transnational, culturally and aesthetically vibrant civic sphere that will ensure a cosmopolitanism that is not a "colourless vagueness." In art historical studies, this is seen, for instance, in the recent discussion on "cosmopolitan modernisms." Conversely, we may see a dual tyranny of a nationalism that is a closure (sometimes stated as "ethno-nationalism" which is disputable), and an internationalism that is evolved through restrictive understanding of historical development within privileged expressions. In art historical terms, where there is a lack of investigation into the reality of multiple modernisms, the possibility of a democratic cosmopolitanism in art is severely curtailed. The advocacy of a liberal cosmopolitanism without a democratic foundation returns art to dominance of historical privileged category. A local community with lack of transnational inputs may sometimes place emphasis on neo-traditionalism which is also a double edged sword, as re kindling with traditions is both liberating and restrictive, which in turn interplays with the push and pull of the collective matrix.

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Friction of calcium phosphate brackets to stainless steel wire (인산칼슘재 브라켓과 강선사이의 마찰저항에 관한 연구)

  • Joo, Hyo-Jin;Park, Young-Guk
    • The korean journal of orthodontics
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    • v.37 no.5
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    • pp.376-385
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    • 2007
  • Esthetic brackets which resemble the color of natural teeth have been widely used. But the frictional resistance of ceramic brackets, a typical esthetic bracket, is greater than that of metal brackets. The purpose of this study was to measure the frictional resistance of the new calcium phosphate brackets (CPB) which were recently developed and to evaluate its clinical usability by comparing the frictional differences of CPB with metal brackets and metal slot inserted ceramic brackets. Methods: Experimental groups were CPB (Hyaline II, Tomy, Tokyo, Japan), metal bracket (Kosaka, Tomy, Tokyo, Japan) and metal slot inserted ceramic bracket (Clarity, 3M Unitek, Monrovia, CA, USA). All of the brackets had 0.022-inch slot sizes. The brackets were tested with $0.019\;{\times}\;0.025$ inch stainless steel wire (3M Unitek, Monrovia, CA, USA). A biologic model was used to simulate the situation which would occur during orthodontic treatment with fixed appliances. Retraction force was applied at a speed of 5 mm/min for 30 seconds. The frictional resistance was measured on a universal testing machine (Instron 4467, Instron, Norwood, MA, USA). Results: CPB showed significantly higher friction than metal brackets (p < 0.05) and lower friction than metal slot inserted ceramic brackets (p < 0.01). Conclusions: CPB can be considered to be a useful orthodontic esthetic bracket with respect to frictional resistance, as its friction is remarkably lower than that of metal slot inserted ceramic brackets.

Integrated analysis and design of composite beams with flexible shear connectors under sagging and hogging moments

  • Wang, A.J.;Chung, K.F.
    • Steel and Composite Structures
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    • v.6 no.6
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    • pp.459-477
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    • 2006
  • A theoretical research project is undertaken to develop integrated analysis and design tools for long span composite beams in modern high-rise buildings, and it aims to develop non-linear finite element models for practical design of composite beams. As the first paper in the series, this paper presents the development study as well as the calibration exercise of the proposed finite element models for simply supported composite beams. Other practical issues such as continuous composite beams, the provision of web openings for passage of building services, the partial continuity offered by the connections to columns as well as the behaviour of both unprotected and protected composite beams under fires will be reported separately. In this paper, details of the finite elements and the material models for both steel and reinforced concrete are first described, and finite element studies of composite beams with full details of test data are then presented. It should be noted that in the proposed finite element models, both steel beams and concrete slabs are modelled with two dimensional plane stress elements whose widths are assigned to be equal to the widths of concrete flanges, and the flange widths and the web thicknesses of steel beams as appropriate. Moreover, each shear connector is modelled with one horizontal spring and one vertical spring to simulate its longitudinal shear and pull-out actions based on measured load-slippage curves of push-out tests of shear connectors. The numerical results are then carefully analyzed and compared with the corresponding test results in terms of load mid-span deflection curves as well as load end-slippage curves. Other deformation characteristics of the composite beams such as stress and strain distributions across the composite cross-sections as well as distributions of shear forces and slippages in shear connectors along the beam spans are also examined in details. It is shown that the numerical results of the composite beams compare well with the test data in terms of various load-deformation characteristics along the entire deformation ranges. Hence, the proposed analysis and design tools are considered to be simple and yet effective for composite beams with practical geometrical dimensions and arrangements. Structural engineers are strongly encouraged to employ the models in their practical work to exploit the full advantages offered by composite construction.

A Study on the Hydrolysis of Sarin and Soman by Merrifield-Type Diaminatedpolystyrene-Cu (II) Heterogeneous Polymers (Merrifield-Type Diaminatedpolystyrene-Cu (II) 불균일 촉매에 의한 Sarin과 Soman 분해반응 연구)

  • 정우영;계영식
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.1
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    • pp.164-175
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    • 2000
  • Three compounds of Cu(II)-loaded N,N,N'-trimethylethylenediaminated Merrifield-type polymers were synthesized with yields higher than 80%, and the hydrolysis reaction rates of O-isopropylmethyl-phosphonofluoridate(GB) and O-pinacolylmethylphosphonofluoridate (GD) catalyzed by them have been surveyed. GB and GD hydrolysis by Cu(II)-loaded polymers occurs via intermediate complex mechanism where rapid equilibrium to form intermediate complex between substrate and Cu(II)-loaded polymers($K_f$) is followed by rate determining hydrolysis step($k_1$). The measured activation parameters for $k_1$ are ${\Delta}H^{\ddag}$ : $17.75{\pm}0.98kJ/mol$ ${\Delta}S^{\ddag}$ / : $-218.42{\pm}3.35J/mol$ K, $E^{\circ}_a$ : $20.22{\pm}0.98kJ/mo1$ for GB and ${\Delta}H^{\ddag}$ / : $11.16{\pm}1.15kJ/mol,$${\Delta}S^{\ddag}$ /: $-258.57{\pm}3.93J/mol$ K, $E^{\circ}_a$ : $13.64{\pm}1.15 kJ/mol$ for GD. Standard enthalpy/entropy changes corresponding to the intermediate complex formation constant $K_f$ are ${\Delta}H^{\circ}$ : $37.05{\pm}2.19 kJ/mo1,$$ {\Delta}S^{\circ}$ : $163.12{\pm}7.49 J/mol$ K and ${\Delta}H^{\circ}$ : 418.59{\pm}2.04 kJ/mol,$ ${\Delta}S^{\circ}$ : 4111.92{\pm}6.98 J/mol$ K for GB and GD, respectively, The electron push-pull mechanism by Cu(II)-loaded polymers lowers the P-F bond breaking energy(~400 kJ/mol) to less than 1/20 compared to the case in which no Cu(II)-loaded resin presents. Analysis of $K_f$ and 4k_1$ over pH=6.5~8.0 range suggest that the GB and GD hydrolysis occurs intramolecularily with $pK_a$ =7.29 for ligated $H_2O$ and $t_{1/2}$=36.9 sec, $pK_a$ = 7.06 and $t_{1/2}$=177.7 sec for GB and GD, respectively.

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Driving Properties of Diesel Injection System using the Multilayer Actuator Structured-ultrasonic Nozzle (적층액츄에이터형 초음파 노즐을 이용한 경유분사 시스템의 구동특성)

  • Kim, Do-Hyung;Kim, Hwa-Soo;Kang, Jin-Hee;Lee, Yu-Hyong;Hwang, Lark-Hoon;Yoo, Ju-Hyun;Hong, Jae-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.174-174
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    • 2008
  • 초음파를 이용하여 액체 연료를 분사하면 균일한 입경과 미립화가 우수하며 에너지 절약과 공해방지등을 할 수 있다. 또한 유속과 유량에 관계없이 이용할 수 있어 반도체 분야의 웨이퍼와 평판 표시기상에 사진 석판용 화학물질의 균일도포 컴퓨터 하드 디스크의 광택제 도포등에 사용할 수 있다. 이처럼 초저의 유출 용량을 요구하는 모든 공정 및 액체연료의 분사가 요구되는 모든 산업에 적용할 수 있는 장점을 가지고 있다. 하지만 현제까지 주로 사용되고 있는 초음파노즐의 액츄에이터는 단판액츄에이터형로 높은 교류전압을 인가해주어야 하는 단점을 가지고 있다. 이 단점을 해결하기 위해 적층액츄에이터형을 사용하여 초음파 노즐 구동하면 낮은 교류 입력전압에서도 단판액츄에이터형 초음파 노즐과 같은 특성을 가질 수 있다. 또한 초음파 노즐의 구동시 기계적인 진동을 이용하므로 많은 열을 발생시켜 노즐의 온도가 상승하여 세라믹 액츄에이터에도 그 영향을 미치게 되어 열적 열화 현상이 일어날 수 있기에 높은 큐리온도를 가지는 액츄에이터가 필요하다. 본 실험에서는 $Pb(Mn_{1/3}Nb_{2/3})_{0.02}(Ni_{1/3}Nb_{2/3})_{0.12}(Zr_{0.50}Ti_{0.50})_{0.86}O_3$ 조성을 사용하여 $900^{\circ}C$의 저온에서 액상 소결하여 적층혈액츄에이터를 제작하였으며 압전 및 유전 특성을 조사하였다. 제작된 초음파노즐을 구동하기 위해서는 약 36kHz의 30V이상의 교류입력전압 할 수 있는 구동회로가 필요로 한다. 압전액츄에이터의 구동을 위해서는 정확한 정현파 입력이 필요 없다. 압전액츄에이터의 특성상 유사 정현파 입력 만으로도 임피던스 매칭이 이루어지기 때문에 설계가 쉽고 간편한 Push-Pull 방식을 이용한 PWM인버터를 사용하였고 인버터의 출력 주파수를 34~38kHz까지 가변 할 수 있게 설계하였다. 제작된 적층액츄에이터형 초음파 노즐을 PWM인버터로 실제 액체 연료인 경유를 분사하였을 때의 액츄에이터의 온도 변화에 따른 공진주파수와 온도 의존성, 전기적 특성을 조사하고 미립화 분사되는 경유의 미립자 크기 및 최대 분사량을 조사 하였다.

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Study on Entering Self-Employment of Young Workers (청년층의 자영업 진입에 관한 연구)

  • Shin, Jaeyoul;Kim, Jongsung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.1
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    • pp.247-257
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    • 2020
  • In recent years, the proportion of youth's self-employed is steadily increasing, and government policy also actively encourages youth to become an entrepreneur. However, most of the domestic precedent studies on the self-employed labor market focus on the middle-aged and the elderly, and previous studies on the self-employed labor market of young people are hardly ever studied. Above all, the study that examines the factors of entry into self-employment of young people is not sufficient and researchers usually utilize the study about for all ages to explain the self-employment market of young people. However, because the young and middle-aged people differ in labor market conditions, family backgrounds, and the level of accumulation of human capital, separate explanations and theories are needed. Therefore, this study explored the factors of entry into self-employment by separating the age group from 15~29 years old. The data used in the analysis was the 9th to 20th data of the Korea Labor Panel Survey. The youth unemployment rate and employment rate were referred to the Economically Active Population Survey of Statistics Korea. The analysis subject was limited to young people who are currently performing economic activities, and the analysis method used multi-level logit model. The main results are summarized as follows. First, the lower the unemployment rate and the higher the employment rate, the younger people tend to enter their own businesses on the structural level. Second on the individual level, young people who possess enough financial capital or pursuit personal aptitude or interest tend to enter self-employment. However, there are no statistical effects of human capital and entrepreneur capital.

Using Implementation Science to Advance Cancer Prevention in India

  • Krishnan, Suneeta;Sivaram, Sudha;Anderson, Benjamin O.;Basu, Partha;Belinson, Jerome L;Bhatla, Neerja;D' Cruz, Anil;Dhillon, Preet K.;Gupta, Prakash C.;Joshi, Niranjan;Jhulka, PK;Kailash, Uma;Kapambwe, Sharon;Katoch, Vishwa Mohan;Kaur, Prabhdeep;Kaur, Tanvir;Mathur, Prashant;Prakash, Anshu;Sankaranarayanan, R;Selvam, Jerard M;Seth, Tulika;Shah, Keerti V;Shastri, Surendra;Siddiqi, Maqsood;Srivastava, Anurag;Trimble, Edward;Rajaraman, Preetha;Mehrotra, Ravi
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3639-3644
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    • 2015
  • Oral, cervical and breast cancers, which are either preventable and/or amenable to early detection and treatment, are the leading causes of cancer-related morbidity and mortality in India. In this paper, we describe implementation science research priorities to catalyze the prevention and control of these cancers in India. Research priorities were organized using a framework based on the implementation science literature and the World Health Organization's definition of health systems. They addressed both community-level as well as health systems-level issues. Community-level or "pull" priorities included the need to identify effective strategies to raise public awareness and understanding of cancer prevention, monitor knowledge levels, and address fear and stigma. Health systems-level or "push" and "infrastructure" priorities included dissemination of evidence-based practices, testing of point-of-care technologies for screening and diagnosis, identification of appropriate service delivery and financing models, and assessment of strategies to enhance the health workforce. Given the extent of available evidence, it is critical that cancer prevention and treatment efforts in India are accelerated. Implementation science research can generate critical insights and evidence to inform this acceleration.

Improved Solubility and Characterization of Photovoltaic Properties D/A Copolymers based on Rigid Structure of Phenothiazine-Quinoxaline (Rigid한 Phenothiazine-Quinoxaline D/A 공액 고분자 구조의 용해성 향상 연구 및 유기박막태양전지로의 특성 분석)

  • Seong, Ki-Ho;Yun, Dae-Hee;Park, Yong-Sung
    • Clean Technology
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    • v.20 no.4
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    • pp.415-424
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    • 2014
  • In this study, two kinds of polymer (PPQX-2hdPTZ (P1), POPQX-2hdPTZ (P2)) were synthesised by Suzuki coupling reaction based on phenothiazine derivative as electron-donor and quinoxaline derivative as electron-acceptor. Microwave synthesis workstation was used to shorten the polymerization time and increase the degree of polymerization. The physical, thermal stability, optical and electrochemical properties of the synthesized polymer were confirmed. The thermal stability of two polymers was outstanding as the initial decomposition temperature was $323-328^{\circ}C$. And additional substituted alkoxy chain on P2 showed higher degree of polymerization. An analysis of electrochemical properties, all polymer had similar HOMO energy level values. Device was fabricated by ITO/PEDOT:PSS/active layer/$BaF_2$/Al structure and photovoltaic properties were confirmed. Each device has a different film thickness and the resulting change in PCE was confirmed. As a result the thinner thickness of the film showed a high efficiency ($PCE_{max}:P1=1.0%$, P2 = 1.1%).

A Study on the Design of Amplifier for Source Driver IC applicable to the large TFT-LCD TV (대형 TFT-LCD TV에 적용 가능한 Source Driver IC 감마보정전압 구동용 앰프설계에 관한 연구)

  • Son, Sang-Hee
    • Journal of IKEEE
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    • v.14 no.2
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    • pp.51-57
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    • 2010
  • A CMOS rail-to-rail high voltage buffer amplifier is proposed to drive the gamma correction reference voltage of large TFT LCD panels. It is operating by a single supply and only shows current consumption of 0.5mA at 18V power supply voltage. The circuit is designed to drive the gamma correction voltage of 8-bit or 10-bit high resolution TFT LCD panels. The buffer has high slew rate, 0.5mA static current and 1k$\Omega$ resistive and capacitive load driving capability. Also, it offers wide supply range, offset voltages below 50mV at 5mA constant output current, and below 2.5mV input referred offset voltage. To achieve wide-swing input and output dynamic range, current mirrored n-channel differential amplifier, p-channel differential amplifier, a class-AB push-pull output stage and a input level detector using hysteresis comparator are applied. The proposed circuit is realized in a high voltage 0.18um 18V CMOS process technology for display driver IC. The circuit operates at supply voltages from 8V to 18V.

An Analysis of Determinants of Medical Cost Inflation using both Deterministic and Stochastic Models (의료비 상승 요인 분석)

  • Kim, Han-Joong;Chun, Ki-Hong
    • Journal of Preventive Medicine and Public Health
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    • v.22 no.4 s.28
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    • pp.542-554
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    • 1989
  • The skyrocketing inflation of medical costs has become a major health problem among most developed countries. Korea, which recently covered the entire population with National Health Insurance, is facing the same problem. The proportion of health expenditure to GNP has increased from 3% to 4.8% during the last decade. This was remarkable, if we consider the rapid economic growth during that time. A few policy analysts began to raise cost containment as an agenda, after recognizing the importance of medical cost inflation. In order to Prepare an appropriate alternative for the agenda, it is necessary to find out reasons for the cost inflation. Then, we should focus on the reasons which are controllable, and those whose control are socially desirable. This study is designed to articulate the theory of medical cost inflation through literature reviews, to find out reasons for cost inflation, by analyzing aggregated data with a deterministic model. Finally to identify determinants of changes in both medical demand and service intensity which are major reasons for cost inflation. The reasons for cost inflation are classified into cost push inflation and demand pull inflation, The former consists of increases in price and intensity of services, while the latter is made of consumer derived demand and supplier induced demand. We used a time series (1983-1987), and cross sectional (over regions) data of health insurance. The deterministic model reveals, that an increase in service intensity is a major cause of inflation in the case of inpatient care, while, more utilization, is a primary attribute in the case of physician visits. Multiple regression analysis shows that an increase in hospital beds is a leading explanatory variable for the increase in hospital care. It also reveals, that an introduction of a deductible clause, an increase in hospital beds and degree of urbanization, are statistically significant variables explaining physician visits. The results are consistent with the existing theory, The magnitude of service intensity is influenced by the level of co-payment, the proportion of old age and an increase in co-payment. In short, an increase in co-payment reduced the utilization, but it induced more intensities or services. We can conclude that the strict fee regulation or increase in the level of co-payment can not be an effective measure for cost containment under the fee for service system. Because the provider can react against the regulation by inducing more services.

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