• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.116.2-116.2
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• 2017

DLC (Diamond like carbon) 박막을 전극 재료로 활용하기 위해서는 높은 전기 저항과 금속성 기판에 대한 낮은 접착력을 극복해야 한다. 본 연구에서는 PECVD에 의해 합성 된 DLC/Ti 전극의 아크 중간층, 질소 도핑, 증착 및 열처리 온도가 접착 강도와 전기적 및 전기 화학적 특성에 주는 영향을 체계적으로 조사 하였다. 그 결과, arc ion plating (AIP) 법에 의해 증착 된 Ti/TiC 중간층의 도입은 스크래치 테스트와 전기화학적 싸이클 테스트에서 향상된 접착 강도 및 수명을 가져온다는 것을 확인 하였다. 그리고 arc 중간층에서의 arc droplet은 DLC 박막의 표면적을 넓혀 전기 화학적 활성도를 높이는 긍정적인 역할을 하였다. 소량의 질소 도핑은 DLC 막의 비저항을 크게 낮춰주었고, 전기화학적 활성도를 증가시켰다. 증착 온도가 높을수록 DLC 막의 sp2/sp3 비율이 증가하였고, 이에 따라 비저항은 감소하였으며 전기 화학적 활성도는 증가하였다. 반면, 가장 높은 전기화학적 전위창은 $300^{\circ}C$ 에서 얻어졌으며 더 높은 온도에서 감소하였다. 열처리 온도를 높일수록 비저항의 감소 및 전기 화학적 활성도가 증가한 반면, 전기화학적 전위창은 지속적으로 감소하였고, 높은 열처리 온도에서는 DLC 전극의 수명이 줄어드는 것을 확인 하였다.

• Journal of Convergence Society for SMB
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• v.6 no.4
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• pp.1-8
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• 2016

In this study, we must investigate what the major success factors that should be considered before introducing to successfully achieve the goal of building enterprise information systems. To evaluate the factors significantly affecting among the success factors. This study is to present by analyzing the typical success factors affecting successful introduction of the system information to companies that lack sufficient information and reviews for the introduction of enterprise information systems.

• Journal of Energy Engineering
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• v.11 no.2
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• pp.106-113
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• 2002

While the demand for energy has shown a sharp increase recently, the supply seems to be limited by the fact that the conventional fossil fuel energy or nuclear energy has its own environmental problems such as, for example, global warming or nuclear waste disposal. To overcome such limited supply of energy, the utilization of natural thermal energy such as river water and sea water as well as treated sewage can be a substantial supplement. The potential use of the unused energy has become more and more feasible these days as the heat pump technology has been advanced. In the present study, the unused energy reserves are estimated on regional and monthly basis for each resource based on the method developed here in order to establish the base data for its utilization. The potential use of the unused energy is also discussed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.2
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• pp.103-108
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• 2007

The absorption spectra of Pu in stock solution were measured using a UV-Vis-NIR spectrophotometer after dissolving $PuO_2\;with\;HNO_3$, HF and $HClO_4$. The spectroscopic characteristics of Pu (III, IV, VI) in acidic, neutral and alkali media were investigated. Also, the intensities and position of major peaks for Pu(VI) were observed with increasing acidic and alkali concentration. The variation of oxidation states of Pu(VI) with an adding reducing reactant was investigated in HCl and NaOH medium.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1207-1217
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• 2013

This study utilizes raw data from "Research on the actual condition of firms' information security" of KISA (2010) and constructs panel dataset to analyze a causal relationship between information security investment and security breach. Using Difference in Difference estimation method we find the following results. First, while the usual causality that information security investment reduces security breach is not supported, the reverse causality that security breach increases information security investment is well explained. Second, contrary to the conventional wisdom, firms in the finance/insurance business sector show the most significant reverse causality pattern.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1165-1172
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• 2012

The purpose of this paper is to investigate the reality of the occupational pension and suggest annuitization over a lifetime of the occupational pension for the purpose of securing income after retirement. A survey and the empirical analysis such as regression and crosstabulation analysis are employed. An research on a case study of an advanced countries is also conducted. The crosstabulation analysis shows that the post-retirement amenities of the self-employed person and the lower income bracket are serious. Individual retirement pension is suggested for the self-employed person and Riester Pension in Germany is recommended for the lower income bracket. The cases in Australia and the UK are useful for annuitization over a lifetime of the occupational pension.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.172-178
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• 1992

The graft copolymerization of acrylonitrile(AN) onto chitosan film by using $F^{3+}(FeCl_3{\cdot}6H_2O)$ as a photosensitizer in an aqueous medium was carried out under ultraviolet(UV) irradiation. The grafted copolymer was identified by using IR spectroscopy and scanning electron microscope. The effects of various polymerization parameters involving monomer concentration, photosensitizer concentration, polymerization time and polymerization temperature were investigated. As monomer concentration and photosensitizer concentration were increased, the percent grafting was increased up to limiting value. And also the percent grafting was found to increase by increasing the polymerization time and temperature.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.139-145
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• 2012

The low speed aerodynamic characteristics of modified sonic arc airfoil which is developed to fit the transonic regime are investigated. This airfoil is designed by using the shape function of sonic arc proposed by Schwendenman, the data of NACA0012, and commercial program Maple. In order to investigate the low speed aerodynamic characteristic of sonic arc airfoil, the numerical analysis is conducted below Mach number 0.3 and the results are compared and analyzed with it of NACA0012 airfoil. At each Mach number, the drag of modified sonic arc airfoil is less 1.5% than NACA0012's drag and the lift of modified sonic arc airfoil is less 2% than NACA0012's lift. The moment coefficient of modified sonic arc airfoil is also less 1.4% than it of NACA0012 at each Mach number.

• Journal of Engineering Education Research
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• v.11 no.2
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• pp.90-101
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• 2008

This study was conducted to develop pre-engineering educational program model based on STEM integration approach. To accomplish this purpose literature review and content validity ratio survey were carried out. The main results of this study were as follows: First, the conceptual model of STEM integration approach was constituted. Second, the conceptual model of pre-engineering educational program model based on STEM integration approach was proposed. Third, the formation steps of inquiry project activity, problem solving activity, and creative engineering design activity were developed to structure the educational program.

• The Journal of the Korean dental association
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• v.19 no.6 s.145
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• pp.535-540
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• 1981

In order to collect the basic data for planning school dental health programmes, the author had examined dental health conditions of 120 males and 120 females of Changgyung Primary School children in the first grade. The percentages of persons with conditions requiring immediate attention, toothbrushing times and daily frequency, df rate, df index, dt index, ft index, it index, DMF rate, DT index, MT index, FT index, IT index, DMFT index, percentages of persons with periodontal status in every of the four categories with soft deposits, calculus, intense gingivitis, and advanced periodontal involvement were calculated and evaluated. The obtained results were as follows: 1. Persons with requiring immediate attention was 7.1% of all the examined children. 2. The df rate was 88.3%, and df index was 3.4 teeth per person. And then the DMF rate was 17.1%, while DMFT index was 0.3 teeth per person. 3. As the periodontal status, the persons with soft deposits was 90.0% of children, calculus 26.3%, intense gingivitis 0.4%, and no advanced periodontal involvement. 4. Average toothbrushing frquency was 1.2 times in a day per person. But 71.5% of toothbrushing was performed before meals, while the others after meals.