• 한국초전도ㆍ저온공학회논문지
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• 제8권1호
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• pp.15-18
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• 2006

A new precursor solution wilt low fluorine content was synthesized for MOD processing of coated conductors. In this study, the precursor solution for MOD processing was synthesized using F-free yttrium and copper precursor. It was shown that crack-free and uniform precursor films were formed after calcination in humidified oxygen atmosphere. Less than 2 hours were required to finish the calcination process. The relatively gradual weight loss during the calcination process is attributed to the feasibility of fast calcination profile. The calcined precursor film was converted to a YBCO film without any secondary phases after annealing in wet $Ar/O_2$ atmosphere. Fully converted film shows uniform microstructure and high critical current density. $(Jc=2.7MA/cm^2) $.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2003년도 정기총회 및 학술대회
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• pp.69-72
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• 2003

This paper presents a signal processing IC for digital HDTV, which is designed to operate in bunt-in HDW or in HD-set-top Box. The chip supports de-multiplexing an ISO/IEC 13818-1 MPEG-2 TS stream. It decodes MPEG-2 MP@HL video bitstream, and provides high-quality scaled video for display on HDTV monitor. The chip consists of ARM7TDMI for TS-Demux, PCI interface, Audio interface, MPEG2 MP@HL video decoder Display processor, Graphic processor, Memory controller, Audio int3face, Smart Card interface and UART. It is fabricated using Sam sung's 0.18-um and the package of 492-pin BGA is used.

• 한국표면공학회지
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• 제43권1호
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• pp.1-6
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• 2010

The effect of organic additives, 1-(3-sulfoproyl)-2-vinylpyridineium hydroxide (SVH) and thiourea (TU), on the precision copper electrodeposition was investigated with optical, electrochemical and x-ray diffraction techniques. It was found that SVH played a r ole as a n accelerator and TU as an i nhibitor during the electroreduction of cupric ions in acidic Cu electroplating solution. Through electrochemical measurements, TU showed more strong interaction with cupric ions than SVH and dominated overall Cu electroplating process when both additives were present in the solution. In the case of three dimensional Cu electrodeposition on the 20 ${\mu}m$-patterned Ni substrates, SVH controlled the upright growth of Cu electrodeposits and so determined its flatness, while TU prohibited the lateral spreading of Cu in the course of pulse-reverse pulse current adaptation. With microscopic observation, we obtained the optimum organic additives composition, that is, 100 ppm SVH and 200 ppm TU during the current pulsation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.5153-5170
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• 2016

The benefit of the scalability and flexibility inherent in cloud computing motivates clients to upload data and computation to public cloud servers. Because data is placed on public clouds, which are very likely to reside outside of the trusted domain of clients, this strategy introduces concerns regarding the security of sensitive client data. Thus, to provide sufficient security for the data stored in the cloud, it is essential to encrypt sensitive data before the data are uploaded onto cloud servers. Although data encryption is considered the most effective solution for protecting sensitive data from unauthorized users, it imposes a significant amount of overhead during the query processing phase, due to the limitations of directly executing operations against encrypted data. Recently, substantial research work that addresses the execution of SQL queries against encrypted data has been conducted. However, there has been little research on top-k join query processing over encrypted data within the cloud computing environments. In this paper, we develop an efficient algorithm that processes a top-k join query against encrypted cloud data. The proposed top-k join processing algorithm is, at an early phase, able to prune unpromising data sets which are guaranteed not to produce top-k highest scores. The experiment results show that the proposed approach provides significant performance gains over the naive solution.

• 한국분말재료학회지
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• 제15권3호
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• pp.221-226
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• 2008

Silver coated copper composite powders were prepared by electroless plating method by controlling the activation and deposition process variables such as feeding rate of silver ions solution, concentration of reductant and molar ratio of activation solution $(NH_4OH/(NH_4)_2SO_4)$ at room temperature. The characteristics of the product were verified by using a scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic absorption (A.A.). It is noted that completely cleansing the copper oxide layers and protecting the copper particles surface from hydrolysis were important to obtain high quality Ag-Cu composite powders. The optimum conditions of Ag-Cu composite powder synthesis were $NH_4OH/(NH_4)_2SO_4$ molar ratio 4, concentration of reductant 15g/l and feeding rate of silver ions solution 2 ml/min.

• 한국주조공학회지
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• 제38권1호
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• pp.9-15
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• 2018

Electromagnetic continuous casting (EMCC) was used to fabricate Ti-6Al-4V alloys with properties suitable for medical applications. Ti-6Al-4V alloy ingots fabricated by EMCC were subjected to heat treatment, such as residual stress removing (RRS), furnace cooling after solution treatment (ST-FC) and water-cooling after solution treatment (ST-WC), in order to obtain characteristics suitable for the standard. After component analysis, the microstructure and mechanical properties (tensile strength and elongation) were evaluated by ICP, gas analysis, OM, SEM, a Rockwell hardness tester and universal testing machine. The Ti-6Al-4V alloy ingot fabricated by EMCC was fabricated without segregation, and the lamellar structure was observed in the RRS and ST-FC specimens. The ST-WC specimen showed only martensite structure. As a result of evaluating the mechanical properties based on the microstructure results, we found that the water-cooled heat treatment condition after the solution treatment was most suitable for the Ti-6Al-4V ELI standard.

• 한국가금학회지
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• 제26권2호
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• pp.85-95
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• 1999

The mechanically deboned chicken meat(MDCM) has several limits in using for in using for in processed meat products as a main material because of poor color and textural properties, chance of microbial contamination and lipid oxidation. There has been a growing interest all over world in the application of MDCM to the surimi process. The surimi made from MDCM contains a high concentration of myofibrillar protein since this processing involves repeated washing processes with an aqueous solution in order to remove heme pigments, fat and other undesirable substances. The quality of the surimi made from MDCM is affected by various processing factors, such as kinds of wash solution, ion strength, washing cycle, temperature, pH changes, composition, part of muscle, particle size, and rigor state etc. A number of researchers havee investigated the effect of the various washing conditions on the properties of surimi gels. A fuller information of all the factors affecting surimi processing and gel formation by heat-induced gelation has not been known yet.

• 한국환경교육학회지:환경교육
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• 제2권1호
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• pp.92-99
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• 1991

According to our secondary school curriculum for natural science and technical circles, there be used 353 of chemical reagents including 24 kinds of harmful and toxicant components. At present, most school are discharging their school laboratory waste water without any chemical and physical treatments. So as to solve the environmental problem for water pollution, this study tried to research a kind of adsorbant utilizing saw dust, wasted wood sources and designed the simple processing system using the adsorbent. This adsorbent was made by extracting lignin substances from raw saw dust under the solution of 0.5N-NaOH at the temperature of $100^{\circ}C$. Their metal removed rates was measured not only by processing of column and vessel. but also by comparing the standard solution and real waste water. The results were proved as more than 90(%) of the adsorptive efficiency on the average from Pb, Cd, Cu except Cr(VI)in case of the school experimental waste water soaked in vessels a long with 4g of the adsorbent for 24 hours. The new processing system enables to remove most harmful and toxicant metals by filtering, sedimenting and adsorbing at the low cost.

• 산업경영시스템학회지
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• 제28권3호
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• pp.98-108
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• 2005

The assembly line balancing problem has been focused by many research works because the efficient management of the assembly line might influence not only the quality of the products but also the working conditions for the workers. This paper deals with U-shape mixed-model assembly line balancing and considers both the processing time and the physical workloads. We suggest the goal programming approach for this situation and to overcome some difficulties of finding optimal solution, we adopt the genetic algorithm that is one of the most promising solution techniques. We tested several test problems and present the results that indicate some improvement for the line balancing as well as the stable performance of the algorithm.

• 한국세라믹학회지
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• 제35권10호
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• pp.1049-1054
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• 1998

In order to fabricate ideal powders new processing is necessary in which the solute atoms in solution ra-pidly move to mix each other to the degree of molecular level the viscosity of solution should be low not to effect the moving of solute atoms and the powders could be directly obtained as crystalline. Supercritical fluid is defined as condensed gas sated up to its critical pressure and temperature. In this paper su-percritical fluid methods were studied as a new ceramic processing of powder preparation. The crystalline powders of TiO2 which are useful for electronic ceramic materials were fabricated by hydrolysis of titanium (IV) ethoxide using ethanol as a supercritical fluid at the condition of 270$\pm$3$^{\circ}C$, 7.3 MPa for 2hr. The cry stalline anatase powders could be directly obtained and its primary particle size was 20 min.