• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.49-52
• /
• 2007

We investigated hydrogen storage and production properties using redox system of iron oxide($Fe_{3}O_{4}$ + $4H_{2}$ ${\leftrightarrows}$ 3Fe + $4H_{2}O$) modified with rhodium, ceria and zirconia under atmospheric pressure. Reduction of iron oxide with hydrogen(hydrogen storage) and re-oxidation of reduced iron oxide with steam(hydrogen evolution) was carried out using a temperature programmed reaction(TPR) technique. On the temperature programmed studies, the effects of amounts of cerium and zirconium on the re-oxidation rate of partial reduced iron oxides were increased with increasing metal additives amount, but the rhodium amount showed little effect on the re-oxidation rate. On the thermal studies, the re-oxidation rates were enhanced with increasing temperature(300 $^{\circ}C$ < 350 $^{\circ}C$).

• 한국전기전자재료학회논문지
• /
• 제15권3호
• /
• pp.275-280
• /
• 2002

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid-stave chase synthesis for production of high temperature superconductor materials were discussed. Oxide superconductors with general formula of $ReBa_2Cu_3O_{7-x}$ (Re=Y, Sm) haute been made by using barium oxide initial powder instead of traditional barium carbonate. Phenomena observed during the grinding of the reactants mixture are presented. Mechano-chemical activation - as a pre-treatment of the reactants mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.

• International journal of advanced smart convergence
• /
• 제9권2호
• /
• pp.179-184
• /
• 2020

Recently, webtoons-based animations have been expanding in Korea, where the role of mobile devices is growing, and media videos such as "YouTube" and "Tik-Tok," which have shorter screening and production cycles than traditional feature films, dramas, and animations, are attracting attention and being enjoyed by public. In order to produce animation content that fits the trend of this shortening video and production cycle, efficiency must be increased not only in story but also in production. Production methods and production technologies need changes to increase efficiency. Animation using motion capture, which is highly production-efficient, is widely used in movies that shows realistic movements, but still has little use in producing cartoon-style animations with exaggerated movements. We analyzed the production method of 2D animation and CG animation and applied the result to CG animation to increase the efficiency of production and production. The methods of production through such experiments are expected to help improve the efficiency of producing animation content that is suitable for the latest trends such as webtoon animation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.334-340
• /
• 2002

This paper proposes a new anti-slip re-adhesion control system fur electric railway vehicle driven by inverter-fed induction motors. This paper introduces an instantaneous tangential farce coefficient estimator between driving wheel and rail, which is based on disturbance observer. The torque command of proposed system regulates to exceed this estimated tangential farce coefficient in order to avoid undesirable slip phenomenon of driving wheels. We have already proposed the anti-slip re-adhesion control system based on disturbance observer for simplified one wheel equivalent model successfully. This paper extend to this system to the actual bogie system, which has four driving wheels driven by two induction motors fed by one inverter. In order to apply anti-slip re-adhesion control to the actual bogie system a new anti-slip re-adhesion control based on both disturbance observer and speed sensor-less vector control of induction motor with quick response are combined. The experimental results and the numerical simulation results prove the validity of the proposed control system.

• 한국축산식품학회지
• /
• 제38권3호
• /
• pp.433-441
• /
• 2018

The objective of present study was to investigate the effect of cooking and their combinations with re-heating methods on the formation of cholesterol oxidation products (COPs) in stored chicken thigh meat. Pan roasting, steaming, oven grilling, charcoal grilling, and microwaving were used for cooking. Re-heating of samples was done using the same cooking methods or microwaving after 3 and 6 d of refrigerated storage. Cooking and re-heating resulted in reduction of crude fat and cholesterol contents of chicken thigh meat depending on storage period before re-heating. Cooking and storage period had no influence on the total amount of COPs. The highest total amount of COPs was observed in meat samples cooked by steaming and reheated by microwaving after 6 d of storage, which showed similar value to raw chicken meat stored for 6 days. However, different re-heating methods formed different types of COPs depending on storage period before re-heating. The high amount (p<0.05) of 25-hydroxycholesterol or ${\alpha}-epoxide$ was detected in meat samples reheated by steaming or microwaving at 3 or 6 d of storage after steamed cooking, respectively. As a result, the combination of steaming and re-heating with microwaving could increase the total amount of COPs in chicken thigh meat and different cooking/re-heating methods could form different types of COPs, even though no significant difference in the total amount of COPs depending on storage period.

• 경영과학
• /
• 제10권2호
• /
• pp.61-77
• /
• 1993

This paper involves a study of developing the production scheduling system in a general job shop type mechanical factory. We consider realistic situations in the job-shop environments, such as alternative machines for operation, the new kinds of processes, the machining center with the plural pallet, the operational situation of each machine during the scheduling period, occurings of urgent orders and machine breakdowns. We also propose the methodology of re-schedule. It is very fast and acceptable for real time production control system. These all functions are implemented on IBM PC and program source is written in PASCAL language.

• 한국경영과학회지
• /
• 제22권1호
• /
• pp.51-58
• /
• 1997

In this paper, we propose a stochastic LP model for determining an optimal input quantity in a single-product multi-stage production system with random yields. Due to the random yields in our model, each stage of the production system can result in defective items, which can be re-processed or scrapped at certain costs. We assume that the random yield at each stage follows an independent discrete empirical distribution. Compared to dynamic programming models that prevail in the literature, our model can easily handle problems of larger sizes.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2004년도 ISMP Pb-free solders and the PCB technologies related to Pb-free solders
• /
• pp.257-261
• /
• 2004

Recently, Pb free solder technologies are developed, and start using for many packaging items. But this technology contains many problems. They are very high re-flow temperature and high cost than normal solder paste. Specially, high re-flow temperature effects heavy damage to packaging and occur many crack to packaging. We developed special ACI (anisotropic conductive ink) that becomes substitution of solder paste. This technology cans adhesive lower temperature such as $120\~150^{\circ}C$. Adhesion time is very short, too. This technology is suitable for mass production.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
• /
• pp.148.2-148.2
• /
• 2011

천연의 메탄 하이드레이트를 생산하기 위한 방법으로는 크게 다음의 세 가지가 알려져 있다; 감압법, 열 자극법, 저해제 주입법. 갑압법이 가장 경제성이 높은 방법으로 보고 있으며, 이를 활용한 개발생산 시에는 해리 이후의 잔류 물에서 하이드레이트 전구체라고 알려진 하이드레이트 구조가 남아 있으며 이는 생산된 메탄 가스의 이송 과정에서 하이드레이트 재생성의 위험을 높이게 된다. 하이드레이트 재생성을 방지할 수 있는 한 가지 수단으로는 억제제를 주입하는 방법이 가능한데, 적절한 양을 주입함으로써 생산의 경제성을 높일 수 있다. 최근 들어 kinetic 억제제의 적용이 인기를 얻고 있는 바, 수용성 고분자인 이들 억제제를 적용하여 초기 하이드레이트 핵 생성을 지연시킬 수 있다. 이들 kinetic 억제제를 메탄 하이드레이트 생산 과정에서 투여하는 방법을 실험적으로 측정해 보았고, 잔류의 하이드레이트 구조에 대한 존재여부에 대하여 간접적으로 증명해보고자 하였다. kinetic 억제제로는 Poly Vinyl Caprolactam (PVCap)을 선택하였다. 해리압력, PVCap 주입 농도에 변화를 주면서 메탄 하이드레이트 생산, 수송과정에서 발생할 수 있는 하이드레이트 재생성 억제에 대한 효과를 실험적으로 측정하였다.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
• /
• pp.530-533
• /
• 2000

Recently, Manufacturers have recognized the importance of recycling because of the limitation of natural resources and new and proposed laws and legislations that assign responsibility to manufacturer for the ultimate disposal of their products and the environmental problems. In this paper, products assembled recyclable parts and non-recyclable parts are collected after consumer usage and go into a plant. And the collected recyclable parts are disassembled through the disassembly process and have three attributes - re-usable attribute, re-manufacturing attribute and dumping attribute. In this situation, we deal with a production planning for recycle-oriented manufacturing system. The proposed model maximizing the profit in a system is formulated as a mixed-integer linear programming. And then a numerical example is used to evaluate the effectiveness of the proposed model