The purpose of this study is to present a novel indicator for analyzing machine failure based on its idle time and productivity. Existing machine repair plan was limited to machine experts from its manufacturing industries. This study evaluates the repair status of machines and extracts machines that need improvement. In this study, F-RPN was calculated using the etching process data provided by the 2018 PHM Data Challenge. Each S(S: Severity), O(O: Occurence), D(D: Detection) is divided into the idle time of the machine, the number of fault data, and the failure rate, respectively. The repair status of machine is quantified through the F-RPN calculated by multiplying S, O, and D. This study conducts a case study of machine in a semiconductor etching process. The process capability index has the disadvantage of not being able to divide the values outside the range. The performance of this index declines when the manufacturing process is under control, hereby introducing F-RPN to evaluate machine status that are difficult to distinguish by process capability index.

팬픽션은 ‘카논(canon)’으로 불리는 원작의 사건에 ‘누락된 장면’을 삽입하기도 하고, 원작의 세계관과 ‘평행 세계’를 구축하여 원작의 주인공을 완전히 새로운 설정에 놓고 이야기를 창작하는 등 기본적으로 원저작물을 토대로 창작된다. 따라서 팬픽션은 원저작자의 2차적 저작물을 창작할 권리와 충돌할 가능성이 있다. 최근에는 ‘그 레이 50가지 그림자’, ‘BBC 셜록’ 등의 사례와 같이, 팬픽션은 특정 팬 중심의 팬문화를 넘어서서 대중적인 영역으로 점점 확대되고 있고 상업적 이용가치도 높아지고 있다. 그러나 팬픽션이 상업적으로 되는 순간, 저작권법 관점에서 아무런 문제가 없을 수 없다. 전통적으로 저작권법 관점에서 팬픽션을 다루 는 방법은, 공정이용 법리로 포섭하여 개별 구체적으로 팬픽션이 공정이용 기준에 부합하는지를 적용해서 원저작자의 2차적 저작물 작성권, 배타적인 권리를 제한할 수 있는지 여부를 따져보는 것이다. 그러나 공정이용 법리는 소송에서 이용자가 원용하게 되는 항변사유의 하나이므로, 소송을 하기 전에는 어떠한 이용이 공정한지 판단하기가 쉽지 않다. 더욱이, 구체적 사안과 사례별로 다양한 항변의 특성 및 팬픽션에 내재된 다양성을 고려한다면 공정이용 분석에 전적으로 의존하는 것은 팬픽션을 보호하는 최선의 방법이라고 할 수 없다. 즉 일부 공정이용 법리로 포섭되지 못한 팬픽션이 저작권법 침해가 되어 사장되고, 팬문화를 위축시키는 것은 대중문화발전에 도움이 되지 못하고, 이는 저작권법의 목표에도 맞지 않는 결과 가 되어버린다. 따라서 개인이 자신의 글쓰기 실력을 향상시킬 뿐만 아니라 대중매체에 표현된 가치와 아이디어를 논평할 수 있는 고유한 공간을 제공받아 그 문화를 발전시키고 향유할 수 있도록 새로운 제도를 모색할 필요가 있다. 저작권법에서 이미 존재하는 라이선스 제도 또는 CCL 등을 활용하자는 주장 등이 있다. 이에 본 논문에서는 저작권법 관점에서 팬픽션의 허용범위를 검토해 보고, 특히 저작재산권의 제한 사유인 공정이용 법리에 팬픽션을 포섭할 수 있는지, 우리나라 및 해외의 적용 사례 등을 살펴보면서 올바른 팬픽션 문화의 확산을 위한 방안 등을 모색해보고자 한다.

The Korean Air-Force aircraft maintenance depot paints the exterior of various aircraft, including high-tech fighters. Aircraft exterior painting is a maintenance process for long-term life management by preventing damage to the aircraft surface due to corrosion. The de-painting process is essential to ensure the quality of aircraft exterior paints. However, because the Korean Air-Force’s de-painting process is currently done with sanding or Plastic Media Blasting (PMB) method, it is exposed to harmful dust and harmful compounds and consumes a lot of manpower. This study compares the de-painting process currently applied by the ROK Air-Force and the more improved process of the US Air Force, and performs economic analysis for the introduction of advanced equipment. It aims to provide information that can determine the optimal time to introduce new facilities through Cost-Volume-Profit (CVP) analysis. As a result of the analysis, it was confirmed that the sanding method had the most economical efficiency up to 2 units per year, the PMB method from 3 to 21 units, and the laser method from 22 units or more. In addition, in a situation where the amount of de-painting work is expected to increase significantly due to the increase in fighters in future, BEP analysis was conducted on the expansion of the existing PMB method and the introduction of a new laser method. As a result of the analysis, it was confirmed that it is more economical to introduce the laser method when the amount of work exceeds the PMB work capacity(18 units per year). The paper would helpful to improve the productivity and quality of the Korean Air Force Aircraft maintenance depot through timely changes of facilities in the workplace in preparation for expansion.

In this study, binderless-WC, WC-6 wt%Co, WC-6wt% 1 and 2.5 B4C materials are fabricated by spark plasma sintering process (SPS process). Each fabricated WC material is almost completely dense, with a relative density up to 99.5 % after the simultaneous application of pressure of 60 MPa. The WC added Co and Co-B4C materials resulted in crystalline growth. The WC with HCP crystal structure has respective interfacial energy (basal facet direction: 1.07 ~ 1.34 J·m−2, prismatic direction: 1.43 ~ 3.02 J·m−2) that depends on the grain growth direction. It is confirmed that the continuous grain growth, biased by the basal facet, which has relatively low energy, is promoted at the WC/Co interface. As abnormal grain growth takes place, the grain size increases more than twice from 0.37 to 0.8 um. It is found through analysis that the hardness property also greatly decreases from about 2661.4 to 1721.4 kg/mm2, along with the grain growth.

Expensive PCBN or ceramic cutting tools are used for processing of difficult-to-cut materials such as Ti and Ni alloy materials. These tools have the problem of breaking easily due to their high hardness but low fracture toughness. To solve these problems, cutting tools that form various coating layers are used in low-cost WC-Co hard material tools, and research on various tool materials is being conducted. In this study, binderless-WC, WC-6 wt%Co, WC-6 wt%Co-1 wt% Mo2C, and WC-6 wt%Co-2.5 wt% Mo2C hard materials are densified using horizontal ball milled WC-Co, WC-Co-Mo2C powders, and spark plasma sintering process (SPS process). Each SPSed Binderless-WC, WC-6 wt%Co-1 wt% Mo2C, and WC-6 wt%Co- 2.5 wt% Mo2C hard materials are almost completely dense, with relative density of up to 99.5 % after the simultaneous application of pressure of 60 MPa and almost no significant change in grain size. The average grain sizes of WC for Binderless- WC, WC-6 wt%Co-1 wt% Mo2C, and WC-6 wt%Co-2.5 wt% Mo2C hard materials are about 0.37, 0.6, 0.54, and 0.43 μm, respectively. Mechanical properties, microstructure, and phase analysis of SPSed Binderless-WC, WC-6 wt%Co-1 wt% Mo2C, and WC-6 wt%Co-2.5 wt% Mo2C hard materials are investigated.

When the product is taken out after the injection process, the surface of the product and the mold are attached and to separate them, it is necessary to consider the frictional force between the mold surface and the product surface. Therefore, to reduce the frictional force, a subtraction gradient for the rib shape is generally applied, and a lapping process is performed to improve the surface roughness of the rib shape surface of the processed mold. Therefore, research is needed to improve the surface roughness when processing the rib. In this study, slotting processing was applied to improve surface roughness when processing ribs. Slotting processing is a processing method that removes material through the feed motion of the tool, and processing is possible regardless of the aspect ratio of the processing shape. A slotting tool was developed for rib machining and a comparative experiment with electric discharge machining was performed. Also after processing, the surface roughness and processing time were compared and analyzed, and the improved surface roughness and fast processing time characteristics of the slotting processing compared to electric discharge processing were confirmed.

In this study, (GaN)1-x(ZnO)x solid solution nanoparticles with a high zinc content are prepared by ultrasonic spray pyrolysis and subsequent nitridation. The structure and morphology of the samples are investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The characterization results show a phase transition from the Zn and Ga-based oxides (ZnO or ZnGa2O4) to a (GaN)1-x (ZnO)x solid solution under an NH3 atmosphere. The effect of the precursor solution concentration and nitridation temperature on the final products are systematically investigated to obtain (GaN)1-x(ZnO)x nanoparticles with a high Zn concentration. It is confirmed that the powder synthesized from the solution in which the ratio of Zn and Ga was set to 0.8:0.2, as the initial precursor composition was composed of about 0.8-mole fraction of Zn, similar to the initially set one, through nitriding treatment at 700oC. Besides, the synthesized nanoparticles exhibited the typical XRD pattern of (GaN)1-x(ZnO)x, and a strong absorption of visible light with a bandgap energy of approximately 2.78 eV, confirming their potential use as a hydrogen production photocatalyst.

In this study, AlSi10Mg alloy powders are synthesized using gas atomization and sieving processes for powder bed fusion (PBF) additive manufacturing. The effect of nozzle diameter (ø = 4.0, 4.5, 5.0 and 8.0 mm) on the gas atomization and sieving size on the properties of the prepared powder are investigated. As the nozzle diameter decreases, the size of the manufactured powder decreases, and the uniformity of the particle size distribution improves. Therefore, the ø 4.0 mm nozzle diameter yields powder with superior properties. Spherically shaped powders can be prepared at a scale suitable for the PBF process with a particle size distribution of 10–45 μm. The Hausner ratio value of the powder is measured to be 1.24. In addition, the yield fraction of the powder prepared in this study is 26.6%, which is higher than the previously reported value of 10–15%. These results indicate that the nozzle diameter and the post-sieve process simultaneously influence the shape of the prepared powder as well as the satellite powder on its surface.

In this work, the results obtained from the simulation of sedimentation of an elliptical cylinder in a viscous fluid are presented. The fluid flow velocity and pressure fields are evaluated by the famous lattice Boltzmann method (LBM). A smoothed profile method (SPM) is considered to enforce the no-slip boundary condition at the curved boundaries of the elliptical cylinder. The coupling between LBM LBM: Lattice Boltzmann Method and SPM SPM: Smoothed Profile Method is done by adding a hydrodynamic force term to the discretized version of the lattice Boltzmann equation. At first, the developed numerical code is validated by applying it to the unbounded laminar flow over an elliptical cylinder for different values of Reynolds number, Re. Later, simulations are carried out for sedimentation of an elliptical particle in a closed enclosure by considering different values for Re defined by terminal settling velocity of the cylinder. The robustness and accuracy of present simulation technique is assessed by comparing the particle trajectories and orientations obtained at different Re with the results from the existing literature. It is observed that, over a period of time, the particle attains steady state constant velocity and sediments horizontally when Re is low (Re=1.9) and moderate (Re=12.6). Whereas, an oscillating pattern for the sedimentation velocity is observed when Re is 32.9.

In this work, narrow-band green-emitting CsPbBr3 particles are embedded in commercialized glass composites by a facile dry process. By optimizing the method through sintering in glass frit (GF) composites including CsBr and PbBr2, used as precursors, the encapsulation of CsPbBr3 particles made them waterproof with green fluorescence. To improve the fluorescent properties by reducing aggregation of CsPbBr3, fumed silica (FS) is additionally used to help particles avoid bulking up in the glass matrix. The CsPbBr3 perovskite/glass composites are characterized using scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy (EDS) maps, which support the existence of CsPbBr3 particles in the glass matrix. The photoluminescence (PL) properties demonstrate that the emission spectrum peak, full width at half maximum (FWHM), and photoluminescence quantum yield (PLQY) values are 519 nm, 17 nm, and 17.7 %. We also confirm the water-resistant properties. To enhance water/moisture stability, the composite sample is put directly into water, with its PLQY monitored periodically under UV light.

Expensive PCBN or ceramic cutting tools are used for the processing of difficult-to-cut materials such as Ti and Ni alloy materials. These tools have a problem of breaking easily due to their high hardness but low fracture toughness. To solve this problem, cutting tools that form various coating layers are used in low-cost WC-Co hard material tools, and researches on various tool materials are being conducted. In this study, WC-5, 10, and 15 wt%Ni hard materials for difficult-to-cut cutting materials are densified using horizontal ball milled WC-Ni powders and pulsed current activated sintering method (PCAS method). Each PCASed WC–Ni hard materials are almost completely dense, with a relative density of up to 99.7 ~ 99.9 %, after the simultaneous application of pressure of 60 MPa and electric current for 2 min; process involves almost no change in the grain size. The average grain sizes of WC and Ni for WC-5, 10, and 15 wt%Ni hard materials are about 1.09 ~ 1.29 and 0.31 ~ 0.51 μm, respectively. Vickers hardness and fracture toughness of WC-5, 10, and 15 wt%Ni hard materials are about 1,923 ~ 1,788 kg/mm2 and 13.2 ~ 14.3 MPa.m1/2, respectively. Microstructure and phase analyses of PCASed WC-Ni hard materials are performed.

최근 환경규제가 강화됨에 따라 액화천연가스(Liquefied Natural Gas)를 이용하여 전력을 생산해내는 신규발전설비인 부유식 LNG 발전설비(floating LNG power plant)가 개발되고 있다. 부유식 LNG 발전설비는 운용 시 증발가스가 발생하고 이를 제거하거나 회수할 수 있는 시스템의 설계가 필요하다. 그러나 해양플랜트는 해상요건에 따라 설계가 상이하고, 부유식 LNG 발전설비의 설계 전 시행착오를 줄이기 위해 지속적으로 수정이 가능한 BOG 회수시스템 공정모사 모델이 필요하다. 따라서 본 연구에서는 상용공정시뮬레이션 프로그램을 통해 부유식 LNG 발전설비에 적합한 모델을 모델링하고자 냉매사용 유무에 따라 서로 다른 BOG(Boil-Off Gas) 회수시스템을 모델링하여 BOG의 회수율과 액화점을 비교 및 분석하였으며, 그 결과 질소냉매를 사용한 BOG 회수시스템 모델을 부유식 LNG 발전설비용 BOG 회수시스템 모델로 제안하고자 한다.

UO2 kernels, a key component of fuel elements for high temperature gas cooled reactors, have usually been prepared by sol-gel methods. Sol-gel processes have a number of advantages, such as simple processes and facilities, and higher sphericity and density. In this study, to produce 900 μm-sized UO2 particles using an external gelation process, contact length extension of the NH3 gas of the broth droplets pass and the improvement of the gelation device capable of spraying 14 MNH4OH solution are used to form 3,000 μm-sized liquid droplets. To produce high-sphericity and high-density UO2 particles, HMTA, which promotes the gelation reaction in the uranium broth solution, is added to diffuse ammonium ions from the outside of the gelation solution during the aging process and generate ammonium ions from the inside of the ADU gel particles. Sufficient gelation inside of ADU gel particles is achieved, and the density of the UO2 spheres that undergo the subsequent treatment is 10.78 g/cm3; the sphericity is analyzed and found to be 0.948, indicating good experimental results.

The enamel powders used traditionally in Korea are produced by a ball-milling process. Because of their irregular shapes, enamel powders exhibit poor flowability. Therefore, polygonal enamel powders are only used for handmade cloisonné crafts. In order to industrialize or automate the process of cloisonné crafts, it is essential to control the size and shape of the powder. In this study, the flowability of the enamel powders was improved using the spheroidization process, which employs the RF plasma treatment. In addition, a simple grid structure and logo were successfully produced using the additive manufacturing process (powder bed fusion), which utilizes spherical enamel powders. The additive manufacturing technology of spherical enamel powders is expected to be widely used in the field of cloisonné crafting in the future.

저작권법이 2011. 12. 2. 개정되어 공정이용 조항이 도입되었다. 이로써 저작물의 통상적인 이용 방법과 충돌하지 아니하고 저작권자의 정당한 이익을 부당하게 해치지 않는 경우에 해당하면 저작물을 이용할 수 있게 되었다. 공정이용 해당 여부를 판단하는 데에는 이용의 목적 및 성격, 저작물의 종류 및 용도, 이용된 부분이 저작물 전체에서 차지하는 비중과 그 중요성, 저작물의 이용이 그 저작물의 현재 시장 또는 가치나 잠재적인 시장 또는 가치에 미치는 영향 등을 고려하여야 한다. 미국 사례로서 선거운동에서 이용허락 없는 원음악저작물을 사용한 경우와 국내 사례로서 실제 골프코스를 화면에 재현하여 스크린 골프장 운영업체에 제공한 경우, 박람회에서 이용허락 없이 홍보 동영상을 재생한 경우, 방송사의 시험문제를 비판하기 위하여 대상 문항을 인터넷에 게시한 경우, 노동착취 행위를 알리는 과정에서 작가를 조롱하기 위하여 예술작품을 복제한 경우를 소개하고 이를 통해 실제 사례에서 위와 같은 판단 요소가 어떻게 고려되는지 살펴보았다. 한편 인공지능의 빅데이터 활용에도 공정이용조항이 적용될 수 있다. 공정이용조항은 저작권 제한 사유를 구체적⋅개별적으로 열거한 것이 아니라 일반적⋅포괄적으로 규정하고 있으므로, 인공지능과 같이 빠르게 발전하는 기술에 따른 다양한 저작물 이용 형태까지도 적시에 파악하여 저작권자와 이용자 또는 일반 공중 사이의 이익을 합리적으로 조율할 수 있다는 장점이 있다. 이때에는 위와 같은 법률상의 고려요소와 함께 저작권자의 권리 보호를 위한 합리적인 노력 내지 조치의 존부, 산재된 이득의 집적 효과, 그로 인한 이해당 사자들이 얻는 이익 또는 불이익의 정도 등을 종합적으로 고려하여야 한다. 그러나 공정이용조항은 인공지능의 빅데이터 활용을 가능하게 하는 임시적인 방편에 불과하다. 예측가능성을 제공하여 기술 발전을 도모하기 위해서는 텍스트 및 데이터 마이닝에 관한 입법적 조치가 요구된다. 입법 과정에서는 4차 산업혁명 시대에 있어 인공지능의 적극적 활용을 위한 제도적 장치 마련의 필요성이라는 측면과 함께, 산재된 저작권의 경미한 이용에서 비롯된 재산적 가치의 이전에 대한 보상의 필요성이라는 측면까지도 충분히 고려되어야 할 것이다.