• Title/Summary/Keyword: critical current

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Superconducting Thick Film by Lateral Field Assisted EPD (측면보조전계 인가 전기영동전착 초전도후막)

  • 전용우;소대화;조용준
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.3
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    • pp.679-685
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    • 2004
  • Although the electrophoretic deposition method has the advantage of simple processing procedure, less fabrication facilities, and easier control for deposition thickness and wire length, providing economical and technical merits, it also has the disadvantages of cracking and porosity phenomena, requiring an improved processing method for higher particle density and constant particle orientation. we have developed an optimization method to increase the particle density and to unify its orientation, and have performed a study to overcome the cracking and porosity problems in the fabricated superconductor. In order to improve the surface uniformity and the conduction properties of the fabricated YBCO thick films, a system that applies alternate voltage vertically has been developed for the first time and applied to the electrophoretic deposition process. The applied alternate electric field caused a force to be exerted on each YBCO particle and resulted in a rotation of the particle in the direction of applied electric field, accomplishing a uniform particle orientation. We name this process as the shaky-aligned electrophoretic deposition method. For commercial utilization and efficiency, in this dissertation, alternating voltage of 60 Hz and 25 ∼ 120 V/cm was proposed to apply it as a subsidiary source for shaky-flow deposition so that the fabricated thin film showed uniform surface morphology with less voids and cracks and Tc,zero of 90 K and the critical current density of 3419 A/$cm^2$.

A Study on User's Requirement Analysis for Improvement of OASIS (한의학술논문검색시스템 기능개선을 위한 사용자 요구 분석에 관한 연구)

  • Han, Jeong-Min;Bae, Sun-Hee;Song, Mi-Young
    • Journal of Information Management
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    • v.40 no.3
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    • pp.79-97
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    • 2009
  • Thanks to current development of many search engines and web technologies, a new semantic searching technology appears, featuring giving a relevant meaning to the keyword beyond the previous keyword search service. On the wave of advance of various search engines, the enhancement of OASIS offered by KIOM is needed as well. To do this, KIOM examined demographic and sociological analysis on their position, status, and career, the convenience of OASIS, and the value of papers offered in OASIS from members who have ever used it. Furthermore, the importance of each area involved in oriental medicine is also examined in terms of a new direction for OASIS improvement. Based on the result of the user survey, it turned out that not only an automatic search system that can find meaning of chinese character-centered key words but also a Authority-system which can distinguish homonym beyond simple keyword search system should be introduced quickly. Also, we reached the conclusion that it is necessary to interconnect a citation index information on references with laboratory information of the agencies concerned and interconnect major web sites around the world by using Open API. OASIS is the only domestic web site for offering papers that cover oriental medicine. Therefore, if requirements about the site in oriental medical circles are analyzed sufficiently and the problems of its information search system are improved, OASIS is expected to play a critical role in the development of oriental medicine.

Fabrication of long SmBCO coated conductor on IBAD-MgO template using co-evaporation method (동시증발법을 이용한 SmBCO/IBAD-MgO 박막 장선재 제조)

  • Ha, H.S.;Kim, H.S.;Ko, R.K.;Yoo, K.K.;Yang, J.S.;Kim, H.K.;Jung, S.W.;Lee, J.H.;Lee, N.J.;Kim, T.H.;Song, K.J.;Ha, D.W.;Oh, S.S.;Youm, D.;Park, C.;Yoo, S.I.;Moon, S.H.;Joo, J.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.241-241
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    • 2007
  • We fabricated SmBCO coated conductors(CCs) on IBAD-MgO templates using co-evaporation method. IBAD-MgO templates consist of PLD-LMO/epi-MgO/IBAD-MgO/Ni-alloy and showed good in-plane texture of below FWHM 7 degree. Evaporation rates of Sm, Ba, and Cu were precisely controlled to get the optimum composition ratio after deposition process. To optimize the oxygen partial pressure of reaction region, wide range of the partial pressure was investigated from 1 mTorr to 15 mTorr. By reducing the oxygen partial pressure to 5mTorr, (103)grains in SmBCO layer have been increased. On the other hand, there were only (001)grains in SmBCO layer deposited at 15 mTorr $O_2$. Deposition temperature was also investigated from $600^{\circ}C\;to\;800^{\circ}C$ to make high Ic SmBCO CCs. SmBCO on IBAD MgO template showed that the Ic increased gradually at higher growth temperature to $800^{\circ}C$, which the highest Jc and Ic is $2.6\;MA/cm^2$ and 500 A/cm-w., respectively.

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Arguments and Some Issues to be Considered for Building the New Administration Capital City in Korea (신 행정수도 건설의 논거와 과제)

  • 안성호
    • Journal of the Korean Geographical Society
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    • v.38 no.2
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    • pp.298-311
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    • 2003
  • Building the new administration capital city, one of presidential candidate Moo-Hyun Rho's election pledges, is now listed as a priority national policy agenda of the Participation Government. However, so many people's negative attitudes ranging from cynical skepticism to firm objections against the national policy agenda may threaten its smooth policy actualization. At this juncture, this paper attempts to present persuasive arguments and discuss some critical issues to be considered for building the new administration capital city successfully. The paper begins with taking a look at the current state of hyper-concentration of Seoul agglomeration area and its harmful effects, paints a vision of 'an evenly developed country as a whole' via illustrating the vision from the Swiss case, and reviews the performance of the precedent governments' reform measures for rectifying the hyper-concentration of Seoul agglomeration area. And then, the paper argues for building the new administration capital city as a potent solution to the problem of excessive concentration of activities in Seoul agglomeration area, as well as a driving force to spur the government to realize the Participation Government' enthusiastic vision: 'a decentralized and evenly developed country as a whole' and 'the hub country in the Northeast Asia'. In addition, the paper discusses the location of the new administration capital city in connection with the forthcoming national unification. Lastly, the paper deals with the important issues such as the procedure of people's approval, the population size and legal status of the new administration capital city, the relationship between building the new administration capital city and decentralization reform, etc.

The Response Prediction of Flexible Pavements Considering Nonlinear Pavement Foundation Behavior (비선형 포장 하부 거동을 고려한 연성 포장의 해석)

  • Kim, Min-Kwan
    • International Journal of Highway Engineering
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    • v.11 no.1
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    • pp.165-175
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    • 2009
  • With the current move towards adopting mechanistic-empirical concepts in the design of pavement structures, state-of-the-art mechanistic analysis methodologies are needed to determine accurate pavement responses, such as stress, strain, and deformation. Previous laboratory studies of pavement foundation geomaterials, i.e., unbound granular materials used in base/subbase layers and fine-grained soils of a prepared subgrade, have shown that the resilient responses followed by nonlinear, stress-dependent behavior under repeated wheel loading. This nonlinear behavior is commonly characterized by stress-dependent resilient modulus material models that need to be incorporated into finite element (FE) based mechanistic pavement analysis methods to predict more realistically predict pavement responses for a mechanistic pavement analysis. Developed user material subroutine using aforementioned resilient model with nonlinear solution technique and convergence scheme with proven performance were successfully employed in general-purpose FE program, ABAQUS. This numerical analysis was investigated in predicted critical responses and domain selection with specific mesh generation was implemented to evaluate better prediction of pavement responses. Results obtained from both axisymmetric and three-dimensional (3D) nonlinear FE analyses were compared and remarkable findings were described for nonlinear FE analysis. The UMAT subroutine performance was also validated with the instrumented full scale pavement test section study results from the Federal Aviation Administration's National Airport Pavement Test Facility (FAA's NAPTF).

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A Comparative Study on the Business and Financial Structure of Public Housing Agencies in Asia: Korea, Japan, Singapore and Hong Kong (아시아 공공주택기관의 사업특성 및 재무현황 비교 연구 : 한국, 일본, 싱가포르, 홍콩을 중심으로)

  • Kim, Yong-Tai;Park, Shin-Young;Cho, Seung-Youn
    • Land and Housing Review
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    • v.2 no.4
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    • pp.529-538
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    • 2011
  • Recently, one of the critical issues in Korea is the huge debt and future role of Korea Land and Housing Corporation. In this regards, the purpose of this study is to get implications from other public housing agencies in Asian countries such as UR of Japan, HDB of Singapore and HA of Hongkong. The changes of housing policy since 1960s, business and financial structure of housing agencies in each nation are investigated and compared. As a result, some policy directions can be proposed as follows : review of current mass housing program, relaxing qualifications for public rental housing, promotion of urban renewal projects, reinforcing cooperation with private sector and local governments, more government's support to LH's financing and loss from businesses for public interests and re-evaluation of LH's debt. The contribution of this study is that suggestions to improve housing policy and to alleviate financial problem of LH are based on the actual conditions of public housing agencies in Asian countries where the housing policy implementation system is similar to Korea, not on the theoretical basis.

Study on Estimation of the Appropriate Social Discount Rate for Evaluating Public Investment Project (공공투자사업 평가의 적정 사회적할인율 추정에 관한 연구)

  • Jang, Byeong-Cheol;Son, Ui-Yeong;O, Mi-Yeong
    • Journal of Korean Society of Transportation
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    • v.28 no.2
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    • pp.65-75
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    • 2010
  • When the cost-benefit analysis is applied for social discount rate(SDR), the choice of SDR to be used in analysis is critical. One of the important issues when public investment project evaluate what is the SDR theory, so there have studied about SDR and no exact answer it so far. In this study, there are three of SDR theories that be estimated social time preference rate, social investment returns and the weighted average method from 1990s, 2000 to 2003 and 2004 to 2008.. First, social time preference method computes consumer's interest rate and the model of Pearce and Ulph(1999). Second, social investment returns method computes private returns of capital. Third, the weighted average method computes the model of Squire, L., Herman G. van der Tak(1975) and private consumption expense and the private investment expense. SDR is estimated in the rage between 2.4% and 3.9% from 2004 to 2008. It is not appropriate that the interest rate was unstable. But it is consider for social equity from present to future generations. Considering this things, downward need to the value of current SDR 5.5%.

Meta-analysis of the Korean Literatures for Developing Clinical Practice Guidelines of Benign Prostatic Hyperplasia (전립선비대증의 진료지침 개발을 위한 한국문헌의 메타분석)

  • Yu, Seung-Hum;Kim, Chun-Bae;Kang, Myung-Geun;Song, Jae-Mann
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.3 s.58
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    • pp.643-664
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    • 1997
  • This study is to provide evidence-based recommendations for the most-effective treatments of benign prostatic hyperplasia based on patient preference or clinical need, and to meta-analyze the Korean literatures for the development of BPH treatment guidelines. For these analyses, extensive literature searches (208 articles), with priority given to the Korean Journal of Urology, were conducted from 1960 to August, 1996. Meta-analysis, like all statistical analysis, has two main functions: data summarization (qualitative meta-analysis) and smoothing o. pattern recognition (quantitative meta-analysis). As well, critical reviews and syntheses with the mean and 90-percent confidence intervals for the likelihood were used to evaluate empirical evidence and significant outcomes of the BPH treatment literatures (106 articles). For this task, the Methodologic Panel for BPH Guidelines was composed of multidisciplinary experts in the field. The results of the study were summarized as follows: For all that watchful waiting is an appropriate treatment strategy for the majority of patients with prostatism, we couldn't find the Korean literatures which carried this article. The literatures on alpha-1-adrenergic receptor blockers provide no evidence to suggest that any one alpha blocker is more effective than another. The finasteride reduces the size of the prostate, on average, and leads to a small yet perceptible reduction in sysptoms. Of all treatment options, prostate surgery with transurethral resection of the prostate (TURP), transurethral incision of the prostate (TUIP), and so on, offers the best chance for symptom improvement. However, surgery also has the highest rates of significant complications. Therefore, surgery need not always be a treatment of last resort. Balloon dilation of the prostatic urethra is clearly less effective than surgery in relieving symptoms, but it is associated with fewer complications. Emerging technologies for treating BPH include lasers, coils, stents, thermal therapy and hyperthermia. Established technologies will also be reanalyzed as results of new trials are reported. Although this study has some limitations due to lacking for good quality literatures, ' it provides a cornerstone for our medical research. It represents the most current scientific knowledge regarding the clinical epidemiology including treatment of BPH. It will be revised and updated as needed.

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Development of a simple and sensitive method to detect enteric viruses from oysters (굴로부터 장바이러스를 검출하기 위한 간단하고 민감한 방법의 개발)

  • Chung, Eun-Young;Je, Hee-Bok;Jun, Hong-Ki;Yoon, Jae-Deuk;Jee, Young-Mee;Cheon, Doo-Sung;Cho, Hae-Wol;Jang, Kyung-Lib
    • Journal of Life Science
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    • v.12 no.1
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    • pp.49-54
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    • 2002
  • Development of a rapid method possessing the requisite sensitivity and specificity for virus monitoring is necessary for protection of the shellfish-consuming public. Oysters tissue usually contains virus particles in relatively small concentrations along with various other substances that can interfere with detection steps. Therefore, the critical point concerning the detection of viruses in shellfish tissues resides in the processing of samples. The current study demonstrated the possibility of purifying small amounts of virus particles at the interface of a 10/50% sucrose gradient after a single round of sucrose gradient ultracentrifugation. We could detect HAV and poliovirus simultaneously from oyster tissues by using two different sets of primer. Furthermore, the method showed a high level of virus recovery rate (>95%) as determined by plaque assays of the final samples. Taken the advantages of the simple and sensitive methods, it was possible to detect 2 pfu of HAV in 5 g of oyster digestive tissues within 24h.

Development of the Hospital Foodservice Facility Evaluation tools based on the General HACCP-based Sanitation Standards and Guidelines (병원급식에 일반위생관리기준과 HACCP 제도 적용을 위한 시설ㆍ설비 위생관리 점검도구 개발)

  • 이정숙;곽동경;강영재
    • Korean journal of food and cookery science
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    • v.19 no.3
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    • pp.339-353
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    • 2003
  • The rapid increase in food borne illness outbreaks in Korea has been one of the major threats to the Nation's Health. Foodservice establishments have been identified as the major place for these outbreaks, mainly due to the lack of sanitary management and sanitary facility management practices. The purposes of the study were to develop hospital foodservice facility evaluation tools, based on the general HACCP-based standards and guidelines, for hospital food service establishments, to ensure the safety of these foodservices and to reduce the risk of food home illness. The scope of this study included: 1) an assessment of the current foodservice sanitation practices and managements for 6 general hospitals, with more than 400 beds, and 3 general hospitals, with less than 400 beds; 2) the development of foodservice establishments sanitation evaluation tools and sanitation standards, based on the HACCP system. The survey data showed varied results between the hospitals surveyed. Most of the hospital foodservice operations had many problems with ventilation and the plumbing. The total dimensional mean scores for the hospitals with more than 400 beds and less than 400 beds were 31.5 and 27.0, respectively. The highest dimension scores were for the water supply facility and lighting, with the lowest for insect and rodent control and toxic materials management. The levels of the mean scores were very low, especially for the general hospitals with less than 400 beds. These low mean scores may have arisen from critical problems within the hospital foodservice operations. The most needed facility management items for improvement were: storage shelf should be spaced 6 inches from the floor and walls, the use of three compartment sinks, utility sinks and cleaning facilities, with a floor drain for cleaning mops or liquid wastes, a ventilation hood designed to prevent dripping onto food, cooking facilities should be disassembled for washing and sanitizing, a separated hand washing sink and a sanitized food board for each area should be provided, all toxic material must have warning labels attached, and be stored in an area away from food preparation under padlock. The evaluation tool consisted of 14 dimensions, with 65 check-off items. The results of this study will provide basic facilities' guidelines to regulators, or foodservice industry personnel, wishing to build, or expend, and establish an efficient flow of food. As a result, food borne illnesses will be effectively prevented, and the Nation's health will be promoted for the development of their own sanitation standards, with a checklist for the safe production of foods.