• Title/Summary/Keyword: 서수

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Effects of Deposition Conditions on Properties of CuNi thin Films Fabricated by Co-Sputtering of Dual Targets (이중 타겟의 동시 스퍼터링을 이용한 CuNi 박막 제작시 증착변수가 박막의 물성에 미치는 영향)

  • Seo, Soo-Hyung;Lee, Jae-Yup;Park, Chang-Kyun;Park, Jin-Seok
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.1
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    • pp.11-16
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    • 2001
  • CuNi alloy films are deposited by co-sputtering of dual targets (Cu and Ni, respectively). Effects of the co-sputtering conditions, such as powers applied to the targets, deposition pressures, and substrate temperatures, on the structural and electrical properties of deposited films are systematically investigated. The composition ratio of Ni/Cu is almost linearly decreased by increasing the DC power applied to the Cu target from 25.6 W to 69.7 W with the RF power applied to the Ni target unchanged(140 W). it is noted that the chamber pressure during deposition and the film thickness give rise to a change of the Ni/Cu ratio within the films deposited. The former may be due to a higher sputtering yield of Cu atom and the latter due to the re-sputtering phenomenon of Cu atoms on the surface of deposited film. The film deposited at higher pressures or at lower substrate temperatures have a smaller crystallite size, a higher electrical resistivity, and much more voids. This may be attributed to a lower surface mobility of sputtered atoms over the substrate.

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A Study on RF High Power Durability of Al-Cu Alloy Electrodes Used in Ladder-type SAW(surface acoustic wave) Filters (Al-Cu 합금 전극막 구조를 갖는 사다리형 SAW filter의 RF-고전력 내구성 특성 고찰)

  • 김남철;이기선;서수정;김지수;김윤동
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.5
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    • pp.435-443
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    • 2001
  • As power durable RF SAW filters, AL-(0∼2wt%)Cu alloy multi-layered thin electrodes were deposited on 42° LiTaO$_3$ piezoelectric substrates by magnetron sputtering process, and then ladder-type RF SAW filters, satisfying the electrical specification of CDMA transmission band, were fabricated through optimizing SAW resonator structures. The temperature of film electrodes in SAW filter was increased with RF power, and reached the maxima to cause a failure of SAW filters at the cut-off frequencies of the RF filter band. As RF power increases, the electrodes of Al-Cu alloy showed higher power durability than that of pure Al. The multi-layer laminated film of Al-1wt.% Cu/Cu/Al-1wt%Cu resulted in the best power durability up to 4W of RF power. Every film electrode, however, was destroyed within seconds whenever applying a critical RF power to SAW filters, regardless of the composition and structure of film electrodes. The breakdown of film electrodes under FR power seems to believe due to the fatigue of electrodes caused by repetitive cyclic stress of surface acoustic wave, which is amplified as RF power increases.

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Deposition and characterization of ZnO thin films for piezo-electric devices (압전 소자용 ZnO 박막의 증착 및 물성 분석)

  • Lee, Jin-Bock;Kim, Kwi-Hyun;Shin, Yang-Ho;Seo, Soo-Hyung;Park, Jin-Seok
    • Proceedings of the KIEE Conference
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    • 1999.11d
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    • pp.959-961
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    • 1999
  • ZnO thin films are deposited by using an RF magnetron sputtering system. Structural and electrical properties are analyzed as a function of deposition conditions, such as RF power, Ar/($Ar+O_2$) ratio, and substrate temperature. The c-axial growth of ZnO is observed to be preferable to the $SiO_2$/Si substrate, rather than the Si substrate. By adding the oxygen gas during deposition, the electrical resistivity of films is increased, but the c-axial growth is inhibited. A pizoelectric resonator of Al/ZnO/Al is also fabricated to estimate the electric-mechanical coupling coefficient($k^2$) of ZnO film. The value of $k^2$ obtained from our work is about 10.14 %.

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Comparative Analysis of Multiattribute Decision Aids with Ordinal Preferences on Attribute Weights (속성 가중치에 대한 서수 정보가 주어질 때 다요소 의사결정 방법의 비교분석에 관한 연구)

  • Ahn Byeong Seok
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.1
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    • pp.161-176
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    • 2005
  • In a situation that ordinal preferences on multiattribute weights are captured, we present two solution approaches: an exact approach and an approximate method. The former, an exact solution approach via interaction with a decision-maker, pursues the progressive reduction of a set of non-dominated alternatives by narrowing down the feasible attribute weights region. Subsequent interactive questions and responses, however, sometimes may not guarantee the best alternative or a complete rank order of a set of alternatives that the decision-maker desires to have. Approximate solution approaches, on the other hand, can be divided into three categories including surrogate weights methods, dominance value-based decision rules, and three classical decision rules. Their efficacies are evaluated in terms of choice accuracy via a simulation analysis. The simulation results indicate that a proposed hybrid approach, intended to combine an exact solution approach through interaction and a dominance value-based approach, is recommendable for aiding a decision making in a case that a final choice is seldom made at single step under attribute weights that are imprecisely specified beyond ordinal descriptions.

Distribution of Private Medical Practitioners' Income from Medical Insurance and its determinants (의원의 의료보험진료비 수입분포와 그 결정요인)

  • 서수교;박재용
    • Health Policy and Management
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    • v.5 no.1
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    • pp.1-30
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    • 1995
  • This study was conducted to investigate the distribution of private medical practitioners' income from the medical insurance and its determinants. Total amount of the medical service fee paid by the medical insurance to 1,268 private clinics(767 in Taegu and 510 in Kyungpook that had been in practice at least for one year) in 1993 was compared by the characteristics of practitioner, clinic, patient and population. The practitioners in 40-49 years of age and 6-10 years inpractice had the highest income. Total income of a clinic was increased with the number of physicians, employees and equipments. The largest income differentials were observed among obstetrics and gynecology clinics and the least differentials were among pediatrics clinics. The characteristics of practitioner, clinic and population accounted for 41.7% of the total variance of income. The important determinants of income were specialty of the clinic, age of the practitioner and number of the employee and equipments. The large income differentials among clinics imply a skewed distribution of patients and thus long waiting time, inefficient utilization of manpower and inadequate quality of care. Effective measures to reduce the income differentials need to be developed.

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Status of Construction of TCM Network Pharmacology Databases and Potential Application of TCMSP to Korean Traditional Medicine - mainly with Sasang-related Herbs (중국 네트워크약리학 데이터베이스 구축 현황 및 TCMSP의 활용가능성 검토 - 사상체질의학의 약물을 중심으로 -)

  • Hwang, Sang Moon;Beck, Jongmin;Suh, Su Yeon;Kwon, Young Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.29 no.6
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    • pp.443-450
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    • 2015
  • The purpose of this study was is to understand how the network pharmacology databases of traditional medicine in China are established and provide suggestion for successful implementation in Traditional Korean Medicine. We searched for network-pharmacology-related TCM Databases provided on the internet, and analysed their contents. Then, we compared herbs related to Sasang with herbs of the TCM Databases. We chose 8 network-pharmacology-related TCM Databases. They shared information about compounds, herbs, formulae, drugs, targets and diseases, and provided interaction networks between these components. In comparison with herbs related to Sasang, TCMSP Database did not have information about 99 herbs in total, and 25 herbs included in major Sasang formulae. The implications and recommendations for Traditional Korean Medicine researches were discussed. Based on the results of this primary study, more related studies should be carried out in the future.

Development of Hysteretic Analysis Model for RC beam with Relocated Plastic Hinge from Column Face (소성힌지가 기둥면에서 이동된 RC보의 이력거동 해석모델)

  • Seo, Soo-Yeon;Yoon, Seung-Joe;Lee, Li-Hyung;Kwon, Young-Joon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.3
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    • pp.167-175
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    • 2002
  • In this paper, an analytical model is proposed for analyzing the hysteretic behavior of RC beam with relocated plastic hinge region under load reversals. The plastic hinge is modeled not to be concentrated on a point but to be distributed on a finite size in beam. This is based on the assumption that the plastic hinge is formed over a certain region, in which the curvature varies. Tangential matrix is reformed using stiffness coefficients including variales such as the length and location of plastic hinge region. In order to construct the hysteretic rule of hinge, modified Takeda rule is also proposed on the base of regression analysis for the previous test results. Previous specimens are analyzed using the proposed model and the result is compared with test result. On the result of the comparison, it was shown that the hysteretic behavior of beams with different location of plastic hinge region could be prediced using the proposed analytical process.

The Effect of Cold Working and Heat Treatment on the Magnetic Properties of in-situ Formed Cu-Fe Composites (In-situ 법(法)에 의한 Cu-Fe 복합조직(複合組織)의 자기적(磁氣的) 특성(特性)에 미치는 가공(加工) 및 열처리(熱處理)의 영향(影響))

  • Shur, S.J.;Park, H.S.
    • Journal of the Korean Society for Heat Treatment
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    • v.2 no.2
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    • pp.38-45
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    • 1989
  • The Cu-Fe permanent magnet were prepared in situ process, which has economic and mass productive merits in producing multi filamentary composites. The purpose of this research was to study the effect of reduction ratio and heat treatment on magnetic property. As the reduction ratio of Cu-Fe wire increased, the filament structure became finer and interfilament distances decreased and the morphology of filament cross section became ribbon shape. As Fe content increased significantly. The coercivity and squareness of Cu-55 wt%Fe composite increased as a reduction ratio became higher, whereas they increased to maximum values at 0.09 mm ${\phi}$ for Cu-30 wt%Fe, and 0.066 mm ${\phi}$ for CU-45 wt%Fe respectively, and decreased for further reduction. The magnetic properties of Cu-Fe composites can be more enhanced by intermediate heat treatment. The best magnetic properties were obtained from Cu-55 wt%Fe composite deformed to 0.054 mm ${\phi}$ and annealed.

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