• 제목/요약/키워드: Research frontier

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CU+ ION EXTRACTION FROM A MODIFIED BERNAS ION SOURCE IN A METAL-ION IMPLANTER

  • Hong, In-Seok;Lee, Hwa-Ryun;Trinh, Tu Anh;Cho, Yong-Sub
    • Nuclear Engineering and Technology
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    • v.41 no.5
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    • pp.709-714
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    • 2009
  • An ion implanter, which can serve as a metal-ion supply, has been constructed and performance tested. Copper ions are generated and extracted from a Bernas ion source with a heating crucible that provides feed gases to sustain the plasma. Sable arc plasmas can be sustained in the ion source for a crucible temperature in excess of $350^{\circ}C$. Stable extraction of the ions is possible for arc Currents less than 0.3 A. Arc currents increase with the induced power of a block cathode and the transverse field in the ion source. $Cu^+$ ions in the extracted beam are separated using a dipole magnet. A $20{\mu}A$ $Cu^+$ ion current can be extracted with a 0.2 A arc current. The ion current can support a dose of $10^{16}ions/cm^2$ over an area of $15\;cm^2$ within a few hours.

Optical transmittance property of PC, PET and PP films by ion implantation (이온주입에 의한 PC, PET, PP의 자외선 투과 특성)

  • Kim, Bo-Young;No, Yong-Oh;Lee, Jae-Sang;Lee, Jae-Hyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1104-1108
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    • 2004
  • A Study has been made of surface modification of various polymers by ion implantation to change the optical transmittance property at ultraviolet ray (UV, $200\sim400nm$). The substrates were PC (Polycarbonate), PET(Polyethyleneteraphtalate) and PP (Polypropylene). The effects of ion implantation on the change of optical transmittance were investigated in relation to ion species, implantation energies and ion fluences. The N, Ar, Kr, Xe ion implantation performed at ion energies from 20 to 50keV. The fluences ranged from $5\times10^{15}$ to $7\times10^{16}ions/cm^2$. UV/Vis transmittance spectroscopy, FT-IR and XPS were used to investigate optical transmittance, chemical structure and surface chemical state of irradiated polymer. Surface color was changed from the yellow to the dark brown and the transmittance of UV ray in the range UV-A($320\sim400nm$) decreased more than 80% after ion implantation.

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Islamic Bank Efficiency in Indonesia: Stochastic Frontier Analysis

  • OCTRINA, Fajra;MARIAM, Alia Gantina Siti
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.751-758
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    • 2021
  • This research is conducted to measure the efficiency level of Islamic banking in Indonesia and also to analyze the factors that can affect its efficiency level. This research used a purposive sampling technique to determine the sample size that will be used, with criteria that the bank has been operating since 2010 and consistently published its financial reports during the research period from 2011 until 2019; therefore, the total sample obtained was 11 samples. Analysis for efficiency level is done by using linear programming Stochastic Frontier Analysis (SFA), with test tool in the form of Frontier 4.1 and Eviews9 to find out what factors that affect efficiency. Efficiency test is done by involving input and output, while influence test used bank-specific variables comprising bank size, bank financial ratio, and macro-economy variable. Research result shows that there are only two banks that are almost close to being fully efficient firms, but the result still does not indicate that Islamic bank works efficiently. Results of the influence test show that factors affecting Islamic banking efficiency in Indonesia are bank size, Capital Adequacy Ratio (CAR), Non-Performing Finance (NPF), and Financing to Deposit Ratio (FDR), while other factors are not influential over the study period.

Electric Power System Design Status for the Proton Accelerator Conventional Facilities of PEFP (양성자 가속기 연구센터 관련 전력설비 설계 현황)

  • Mun, K.;Jeon, G.P.;Min, Y.S.;Nam, J.M.;Kim, J.Y.;Kim, B.H.;Jeong, W.S.;Yoo, S.T.
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.496-497
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    • 2006
  • 90년대에 들어서면서부터 미래원천기술 개발에 필요한 양성자원 및 중성자원의 중요성이 부각됨으로써, 이에 적합한 고에너지(수백 MeV${\sim}$수 GeV) 및 대전류(수십 mA)의 대형 양성자 가속기가 개발되어 반도체 생산, 의료장비 등 여러 분야에 널리 적용되고 있는 추세이다[1, 2]. 이에 양성자 사업단은 21세기 미래 원천기술을 개발하고 산업경쟁력을 제고하며 공공복지를 증진시킬 수 있는 양성자가속기를 개발하여, NT, BT, IT, ST등 중요 국가과학기술분야의 발전기반을 확충하기 위한 프론티어 사업목표로 하고 있으며 이에 부응할 수 있는 양성자 가속기 연구센터 건설계획을 설정하여 추진 중에 있다. 본 논문에서는 양성자 가속기 연구센터 건설계획 과정 중에서 전력설비 설계 방법, 즉 154kV 수전 설비, 직류전원계통, 무정전 전원계통 설비, 접지 및 피뢰설비의 기능 및 특징에 관해 기술하고자 한다.

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Frontier Leadership Program for Engineering Students in Gunma University

  • Ishijima, Shunichi;Shimizu, Naoto;Masuda, Tsuyoshi;Seki, Yoichi;Tobita, Seiji
    • Journal of Engineering Education Research
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    • v.15 no.4
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    • pp.21-25
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    • 2012
  • In this paper, the purpose and overview of the "Frontier Leadership Program for Engineering Students through Joint Participation of Higher Education and the Industrial Sector" (FLC: Frontier Leadership Course) in Gunma University is reported together with our achievements during the last three years. The purpose of this special educational program is to promote and educate selected students who are highly motivated to learn science & mathematics and to become an active leader in industrial sectors or research institutes. The activity can be divided into two categories: "Student-Proposed Stream" and "Advanced Research Stream". These activities were found to be useful to cultivate student's leadership and global communication ability. Furthermore, most of the FLC students cultivated the excellent academic performance and five students among them will be allowed to skip their fourth undergraduate year and enter directly into our graduate school.

Measuring the Performance of Technology Transfer Activities of the Public Research Institutes in Korea (국내 공공 연구기관들의 기술이전 효율성 분석)

  • Ok, Joo-Young;Kim, Byung-Keun
    • Journal of Technology Innovation
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    • v.17 no.2
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    • pp.131-158
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    • 2009
  • We examine the effects of environmental or organizational factors on the performance of TLOs(technology transfer offices) in the PRIs(Public research institutes) using SFA(Stochastic Frontier Analysis), a technique for estimating the efficiency of DMUs(decision making units). In SFA, independent variables are assumed to determine the efficient production technique(production frontier) or affect the efficiency of DMUs. Previous researchs show that input variables such as number of personnel, R&D expenditure affect the production frontier while environmental or organizational variables affect the efficiency. We tried to estimate various types of models to find out whether environmental or organizational variables affect output variables differently from the previous research. Main empirical findings are as follows. First, R&D expenditure tends to increase all output variables considered. Second, environmental factors such as type of institutions and location of institutions affect the level of outputs. Third, organizational factors such as reward system for technology transfer also appear to affect the output variables. Fourth, environmental or organizational variables affect the production frontier directly rather than affect the efficiency of DMUs. Lastly, the efficiency of each DMU appear to be 1 or near to 1. Since almost all DMUs are equally efficient, it may not be effective to evaluate technology transfer activities of PRIs by efficiency criteria. We believe that this research should be complemented by additional data. More general types of production function need to be considered, and new techniques with concepts like output distance functions need to be developed to analyse multiple outputs simultaneously.

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An Analysis on the Determinants of Efficiency of the Pharmaceutical Firms using Stochastic Frontier Analysis (Stochastic Frontier Analysis를 이용한 제약회사의 효율성과 그 결정요인분석)

  • Sakong, Jin;Kim, Jeongkyu
    • Health Policy and Management
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    • v.25 no.2
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    • pp.97-106
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    • 2015
  • Background & Methods: The purpose of this research is to estimate the efficiency of the pharmaceutical firms and the determinants of their efficiency. Stochastic frontier analysis(SFA) and panel study are applied to the data of 60 domestic pharmaceutical firms from 2006 to 2012. Results & Conclusion: First, the result of the stochastic frontier analysis shows that overall efficiency of the pharmaceutical firms is increasing as time goes by. However, if firms are classified by the scale, the larger firms show more efficiency and if classified by the degree of innovativeness, the innovative firms show more efficiency compared to the non-innovative firms. This evidences show that the scale and R&D investment have significant relationships with the efficiency of the pharmaceutical firms. Therefore, it is necessary to increase the national level of investment for the fundamental researches to vitalize R&D of the new drugs. Second, the result of estimation of the determinants of efficiency shows that the firms with larger sales promotion expenses and entertainment expenses have less efficiency compared to the other firms. This can be explained by the structural characteristics of the small generic pharmaceutical firms. Therefore, the government had better make the pharmaceutical firms to reduce sales promotion and entertainment expenses and increase R&D expenses by introducing systems such as global budgeting system on medicine or reference pricing system.

LiDAR-based Mobile Robot Exploration Considering Navigability in Indoor Environments (실내 환경에서의 주행가능성을 고려한 라이다 기반 이동 로봇 탐사 기법)

  • Hyejeong Ryu;Jinwoo Choi;Taehyeon Kim
    • The Journal of Korea Robotics Society
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    • v.18 no.4
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    • pp.487-495
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    • 2023
  • This paper presents a method for autonomous exploration of indoor environments using a 2-dimensional Light Detection And Ranging (LiDAR) scanner. The proposed frontier-based exploration method considers navigability from the current robot position to extracted frontier targets. An approach to constructing the point cloud grid map that accurately reflects the occupancy probability of glass obstacles is proposed, enabling identification of safe frontier grids on the safety grid map calculated from the point cloud grid map. Navigability, indicating whether the robot can successfully navigate to each frontier target, is calculated by applying the skeletonization-informed rapidly exploring random tree algorithm to the safety grid map. While conventional exploration approaches have focused on frontier detection and target position/direction decision, the proposed method discusses a safe navigation approach for the overall exploration process until the completion of mapping. Real-world experiments have been conducted to verify that the proposed method leads the robot to avoid glass obstacles and safely navigate the entire environment, constructing the point cloud map and calculating the navigability with low computing time deviation.

Influence of kneading ratio on the binding interaction of coke aggregates on manufacturing a carbon block

  • Kim, Jong Gu;Kim, Ji Hong;Bai, Byong Chol;Choi, Yun Jeong;Im, Ji Sun;Bae, Tae-Sung;Lee, Young-Seak
    • Carbon letters
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    • v.28
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    • pp.24-30
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    • 2018
  • Coke aggregates and carbon artifacts were produced to investigate the interactions of coke and pitch during the kneading process. In addition, the kneading ratio of the coke and binder pitch for the coke aggregates was controlled to identify the formation of voids and pores during carbonization at $900^{\circ}C$. Experiments and thermogravimetric analysis revealed that carbon yields were improved over the theoretical yield calculated by the weight loss of the coke and binder pitch; the improvement was due to the binding interactions between the coke particles and binder pitch by the kneading process. The true, apparent, and bulk densities fluctuated according to the kneading ratio. This study confirmed that an excessive or insufficient kneading ratio decreases the density with degradation of the packing characteristics. The porosity analysis indicated that formation of voids and pores by the binder pitch increased the porosity after carbonization. Image analysis confirmed that the kneading ratio affected the formation of the coke domains and the voids and pores, which revealed the relations among the carbon yields, density, and porosity.