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        검색결과 4,563

        1241.
        2016.04 구독 인증기관·개인회원 무료
        최근 10년간 쌀 생산량과 비교해 쌀 소비량은 크게 감소하였다. 이에 쌀 소비를 진작시키기 위한 다양한 쌀 가공품 과 기능성 쌀 소재에 대한 개발 필요성이 대두되었으며, 기능성 쌀 소재 중 소화도와 관련이 있는 저항전분(Resistant Starch, RS)에 관심이 집중되고 있다. 본 연구의 목적은 유기농 쌀 가루의 산 처리 기술을 개발하고, 이들의 물리 화학 적 특성을 알아보는 것이다. 구연산처리를 한 유기농 쌀 가루는 구연산(citric acid, CA)을 쌀가루의 건량기준 중량대비 0, 20, 30, 40% 농도로 처리한 후 105℃, 150℃에서 각각 건식으로 반응시켜 총 8가지의 구연산처리 유기농 쌀가루 (Dry-processed Citrate Organic Rice Flour, DCORF)를 제조하고 이들의 물리화학적 특성을 연구하였다. Degree of substitution (DS)는 CA 농도와 반응온도가 증가할수록 높은 결과를 나타내었다. Differential Scanning Calorimeter (DSC) 를 이용하여 열적 특성을 확인한 결과 CA의 양과 반응 온도가 증가할수록 호화개시온도는 55.02℃에서 39.66℃(105℃ 40%)까지 낮아지고, 150℃에서 처리한 시료에서는 열적 특성이 나타나지 않음을 확인할 수 있었다. X-ray diffractometer 를 이용하여 결정구조와 상대적결정화도(relative crystallinity)를 확인한 결과 호화에 따른 결정구조의 변화는 확인되었 으나 A형 결정구조는 변하지 않았으며, 상대적 결정화도는 105℃에서는 큰 변화가 없었으나 150℃에서는 크게 줄어 드는 것으로 확인되었다. 팽윤력(Swelling Power)은 CA와 열처리의 정도가 커질수록 감소하는 양상을 나타내었고, 용 해도(Solubility)는 열처리의 강도가 높을수록 낮아지고, CA의 양이 많아질수록 높아지는 양상을 띠었다. RS, RDS, SDS, 와 Total starch의 양을 측정한 결과 CA 농도와 열처리 강도가 높아질수록 RDS와 SDS, Total starch는 감소하였 고, RS함량은 현저히 증가하였다. 이러한 결과로 미루어, 유기농 쌀가루에 구연산으로 건식 열처리를 하면 난소화성을 가지게 되는 것을 확인 할 수 있었으며, 본 연구 결과가 산업적으로 난소화성 기능성 쌀 제품을 개발하는데 도움이 될 것으로 기대된다.
        1243.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the development environment is changing with the development of information communication technology, the systems that were used by each service became used with integration. In the process of integrating from existing legacy systems to new system, it should be smoothly integrated or shared, however, it cannot help holding existing technology or component due to significant cost burden for conversion. In this paper, it was not only classified by types with analyzing the various elements that make up legacy system but an approach and monitoring system were developed to each type. After System application results, data's information generated in each process is provided to other system in real time, so that it has not only secured the work efficiency and reliability but also it is made possible by integrating data in various formats for efficient data management, rapid search and tracking to history. With real-time monitoring system developed in this study, It can be very useful in a variety of industries which require real-time monitoring of distributed legacy system data.
        4,000원
        1244.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this paper is to analyze the problems and the sources of defective products and draw improvement plans in a small plastic boat manufacturing process using TOC (Theory Of Constraints) and statistical analysis. TOC is a methodology to present a scheme for optimization of production process by finding the CCR (Capacity Constraints Resource) in the organization or the all production process through the concentration improvement activity. In this paper, we found and reformed constraints and bottlenecks in plastic boat manufacturing process in the target company for less defect ratio and production cost by applying DBR (Drum, Buffer, Rope) scheduling. And we set the threshold values for the critical process variables using statistical analysis. The result can be summarized as follows. First, CCRs in inventory control, material mix, and oven setting were found and solutions were suggested by applying DBR method. Second, the logical thinking process was utilized to find core conflict factors and draw solutions. Third, to specify the solution plan, experiment data were statistically analyzed. Data were collected from the daily journal addressing the details of 96 products such as temperature, humidity, duration and temperature of heating process, rotation speed, duration time of cooling, and the temperature of removal process. Basic statistics and logistic regression analysis were conducted with the defection as the dependent variable. Finally, critical values for major processes were proposed based on the analysis. This paper has a practical importance in contribution to the quality level of the target company through theoretical approach, TOC, and statistical analysis. However, limited number of data might depreciate the significance of the analysis and therefore it will be interesting further research direction to specify the significant manufacturing conditions across different products and processes.
        4,000원
        1245.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Patent management activities are considered to play a key role for technology-based firms under the recent knowledge-based economies. This is because intellectual property, including patents, can act as a system for continuous profit generation by protecting firms’ products, processes and services. In Korea, healthcare industry is now regarded as one of the promising next generation industries. Despite the promise of healthcare industry, Korean healthcare product manufacturers are faced with turbulent business changes, such as market opening. Even though there are various industrial studies on the effect of patent management activities on firm outcome, previous studies have hardly paid attention to Korean healthcare product manufacturing firms. For this reason, this study identifies the effect of patent management activities, such as patenting activeness, technical excellence and cooperation degree, on firm outcomes, including financial profitability and firm growth, with respect to the Korean healthcare product manufacturers. In this study, we located 86 Korean healthcare manufacturing firms from KORCHAMBIZ and DART, and then collected the data of their patenting activities and outcomes between 2001 and 2013. By applying factor analysis and regression analysis, our empirical study found that firms’ patenting activeness has the significant positive relationship on firms’ financial profitability, and firms’ patenting activeness and technical excellence have the significant positive relationship on firms’ financial growth. Our study is an initial attempt to identify the effect of patent management activities on firm outcome within Korean healthcare product manufacturing industry, and thus its results can be used as the basis to formulate national policies for Korean healthcare product industry.
        4,000원
        1246.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 각각의 혁신역량 요소가 기업의 혁신방법 선택에 미치는 영향을 EU 국가와 비교함으로써 국내 제조기업의 기술수준을 파악하고, 최신 자료를 통해 그 변화를 살 펴 혁신역량 제고를 위한 정책적 시사점을 도출하고자 한다. 이를 위해 유사한 데이터와 모 형으로 분석하였으며 그 결과, 2005년 한국은 대략 EU의 부진국가와 중간국가 사이에 위치 하며, 2014년에는 혁신비용지출에 따른 연구개발비 비중의 증가, 내부혁신활동 수행, 고기술 업종의 연구개발 선택 등 혁신역량이 일부 개선된 모습을 보였다. 따라서 혁신역량제고를 위 해서는 기업의 혁신비용지출에 대한 지원과 고기술기업, 특허출원 및 산학연 협력을 실시하 는 기업을 위한 제도적 보완이 필요할 것으로 보인다.
        5,500원
        1247.
        2016.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A roll-bonding process was applied to fabricate an AA1050/AZ91/AA1050 laminate complex sheet. Two AA1050 and one AZ91 magnesium sheets of 2 mm thickness, 30 mm width and 200 mm length were stacked up after surface treatment that included degreasing and wire brushing; material was then reduced to a thickness of 3 mm by one-pass cold rolling. The laminate sheet bonded by the rolling was further reduced to 2 mm in thickness by conventional rolling. The rolling was performed at 623K without lubricant using a 2-high mill with a roll diameter of 210 mm. The rolling speed was 15.9 m/min. The AA1050/AZ91/AA1050 laminate complex sheet fabricated by roll bonding was then annealed at 373~573K for 0.5h. The microstructure of the complex sheets was revealed by electron back scatter diffraction (EBSD) measurement; the mechanical properties were investigated by tensile testing and hardness testing. The strength of the complex sheet was found to increase by 11 % and the tensile elongation decreased by 7%, compared to those values of the starting material. In addition, the hardness of the AZ91 Mg region was slightly higher than those of the AA1050 regions. Both AA1050 and AZ91 showed a typical deformation structure in which the grains were elongated in the
        4,000원
        1248.
        2016.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To study the dispersion factors of silica sol prepared from fumed silica powder, we prepared silica sol under an aqueous system using a batch type bead mill. The dispersion properties of silica sol have a close relationship to dispersion factors such as pH, milling time and speed, the size and amount of zirconia beads, the solid content of fumed silica, and the shape and diameter of the milling impellers. Especially, the silica particles in silica sol were found to show dispersion stability on a pH value above 7, due to the electrostatic repulsion between the particles having a high zeta potential value. The shape and diameter of the impellers installed in the bead mill for the dispersion of fumed silica was very important in reducing the particle size of the aggregated silica. The median particle size (D50) of silica sol obtained after milling was also optimized according to the variation of the size and amount of the zirconia beads that were used as the grinding medium, and according to the solid content of fumed silica. The dispersion properties of silica sol were investigated using zeta potential, turbiscan, particle size analyzer, and transmission electron microscopy.
        4,000원
        1249.
        2016.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To achieve the fabrication of high-quality Ag-coated Cu particles through a wet chemical process, we reported herein pretreatment conditions using an ammonium-based mixed solvent for the removal of a Cu2O layer on Cu particles that were oxidized in air for 1 hr at 200 oC or for 3 days at room temperature. Furthermore, we discussed the results of post-Ag plating with respect to removal level of the oxide layer. X-ray diffraction results revealed that the removal rate of the oxide layer is directly proportional to the concentration of the pretreatment solvent. With the results of Auger electron spectroscopy using oxidized Cu plates, the concentrations required to completely remove 50-nm-thick and 2-nm-thick oxides within 5 min were determined to be X2.5 and X0.13. However, the optimal concentrations in an actual Ag plating process using Cu powder increased to X0.4 and X0.5, respectively, because the oxidation in powder may be accelerated and the complete removal of oxide should be tuned to the thickest oxide layer among all the particles. Back-scattered electron images showed the formation of pure fine Ag particles instead of a uniform and smooth Ag coating in the Ag plating performed after incomplete removal of the oxide layer, indicating that the remaining oxide layer obstructs heterogeneous nucleation and plating by reduced Ag atoms.
        4,000원
        1250.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구에서는 계면활성제에 작용기를 첨가하여 유화제 뿐만 아니라 합성에서의 모노머로 작 용할 수 있는 반응성 계면활성제를 합성하였다. 반응성 계면 활성제는 메타아크릴 산, 아크릴산과 비이 온성 계면 활성제인 폴리 옥시 에틸렌 라우릴 에테르 (POE 23)를 사용하여 합성되었으며 벤젠을 용매 로서 사용하였고, P-TsOH를 촉매로서 사용 하였다. 합성된 계면 활성제는 FT-IR, 1H-NMR 스펙트 럼, 원소 분석을 하였다. 물성 평가는 HLB, Cloud point, 표면 장력, 임계 미셀 농도를 측정 하였다. HLB 값은 11.62∼12.09 범위로 평가 하였다. cmc 값은 표면 장력 법으로 측정하였을 때 1×10-4~5×10-4 의 값을 가졌다. 실험을 통해 측정된 Cloud point은 35, 39℃ 이었다. 합성 계면 활성 제의 유화 특성은 polyoxyethylene lauryl ether보다 낮았다. 또한, 유화력은 벤젠에서 보다 대두유에서 더 좋았다. 실험결과 합성 수율은 93.27 ∼ 94.49%로 확인되었다.
        4,000원
        1251.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electromagnetic interference(EMI) shielding sheet of grid pattern for the wireless charger has been designed by using grid pattern metal sheet, PET & DST stacking and laminating technology. For this purpose, the twisting protection and the bubbling prevention device, the automatic position adjustment controller, the visual sensors and the motor actuator for controller, the EMI shielding sheet cutting device and the main control system have been developed for manufacturing the apparatus. As the study result, the development on manufacturing the equipment and shielding sheet of the EMI shielding sheet of grid pattern for the wireless charger having the lamination productivity of 27.4m/min exceeded the target of 8m/min in this study. In addition, the magnetic induction and the applicable shielding sheet were prepared in the magnetic resonance system, all of the two wireless charging system. The power with a band of average 6.87MHz of shielding sheet was greater than the target of 30dB to 32.57dB. The available frequency with a band of average 7.95MHz the target was exceeded by a 7.00MHz.
        4,000원
        1252.
        2016.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, 5 um sized ZrSiO4 was ground to 1.9 um, 0.3 um, and 0.1 um sized powders by wet high energy milling process, and the sintering characteristics were observed. Pure ZrSiO4 itself can-not be sintered to these levels of theoretical density, but it was possible to sinter ZrSiO4 powder of nano-scale size of, −0.1 um to the theoretical density and to lower the sintering temperature for full density. Also, the decomposition of ZrSiO4 with a size in the micron range resulted in the formation of monoclinic ZrO2; however, in the nano sized range, the decomposition resulted in the tetragonal phase of ZrO2. So, it was possible to improve the sintering characteristics of nano-sized ZrSiO4 powders.
        4,000원
        1253.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        반도체 및 디스플레이 공정에서 배출되는 N2/NF3 혼합 가스 분리를 위한 폴리썰폰 중공사막 제조 연구를 수행하였다. 먼저 non-solvent induced phase separation (NIPS)와 vapor induced phase separation (VIPS) 혼합 공정을 이용하여 기체 투과성이 높은 고분자 중공사막을 제조하였다. 제조된 중공사막 표면에 PDMS(polydimethylsiloxiane)와 Teflon AF1600® 고 분자 소재를 이용하여 얇은 박막을 추가적으로 코팅하는 방법으로 기체 분리막을 완성하였다. 제조된 분리막은 코팅된 고분 자 소재의 기체 분리 특성에 따라 상이한 N2/NF3 분리 성능을 보여주었다. 특히 Teflon AF1600® 이 코팅된 중공사막의 경우 N2/NF3 분리 성능(> 14)을 보여주었고, N2 투과도는 4.5 GPU를 나타내었다. 상용 폴리썰폰 막과 비교해 볼 때, 투과도는 약간 감소하였지만 기체 선택도는 크게 증가하였다. 이런 특징은 N2/NF3를 분리하는 분리막 구조로써 큰 가능성을 지니는 것으로 판단된다. Abstract:
        4,000원
        1254.
        2016.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In order to fabricate porous mullite ceramics with controlled pore structure and improved mechanical strength, a freeze casting route has been processed using camphene mixed with tertiary-butyl alcohol (TBA) and coal fly ash/alumina as the solvent and the ceramic material, respectively. After sintering, the solidification characteristics of camphene and TBA solvent were evident in the pore morphology, i.e., dendritic and straight pore channels formed along the solidification directions of camphene and TBA ice, respectively, after sublimation. Also, the presence of microcracks was observed in the bodies sintered at 1500 oC, mainly due to the difference in solidification volume change between camphene and TBA. The compressive strength of the sintered bodies was found generally to be dependent, in an inverse manner, on the porosity, which was mainly determined by the processing conditions. After sintering at 1300~1500 oC with 30~50 wt% solid loading, the resulting mullite ceramics showed porosity and compressive strength values in ranges of 83.8~43.1% and 3.7~206.8 MPa, respectively.
        4,000원
        1255.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study focuses on fabricating silver flake powder by a mechanical milling process and investigating the formation of flake-shaped particles during milling. The silver flake powder is fabricated by varying the mechanical milling parameters such as the amount of powder, ball size, impeller rotation speed, and milling time of the attrition ballmill. The particle size of the silver flake powder decreases with increasing amount of powder; however, it increases with increasing impeller rotation speed. The change in the particle size of the silver flake powder is analyzed based on elastic collision between the balls, taking energy loss of the balls due to the powder into consideration. The change in the particle size of the silver flake powder with mechanical milling parameters is consistent with the change in the diameter of the elastic deformation contact area of the ball, due to the collision between the balls, with milling parameters. The flake-shaped silver particles are formed at the elastic deformation contact area of the ball due to the collision. Keywords: Flake powder, Milling, Ball collision, Elastic deformation
        4,000원
        1256.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 역전기투석 응용을 위해 엔지니어링 고분자 기반의 이오노머와 다공성 폴리에틸렌 지지체를 사용 한 세공충진 이온교환막을 제조하고 이를 결합한 이오노머-세공충진 복합막을 제조하였다. 이온전도도가 높은 이오노머와 우 수한 기계적 강도를 가진 세공충진막을 결합함으로써 상용 이온교환막(AMX/CMX, Astom Corp., Japan) 대비 동등 수준의 전기화학적 특성 및 응용에 적합한 물리적 안정성을 확보할 수 있었다. 제조된 이오노머-세공충진 복합막을 이용하여 역전기 투석 성능을 평가한 결과 상용막 대비 음이온 교환막의 경우 86.4%, 양이온 교환막은 104.8% 수준의 우수한 발전성능을 나 타내었다.
        4,300원
        1257.
        2016.02 구독 인증기관 무료, 개인회원 유료
        정수슬러지를 탄화 및 활성처리하여 흡착제를 제조하였으며, 이를 이용한 황화수소 흡착특성을 고찰하였다. 제조 된 흡착제에 대한 BET측정 및 SEM 등 물성분석을 실시하였으며, 황화수소를 대상으로 회분식의 흡착평형실험 을 실시하였다. 실험변수로는 활성처리시 적용되는 약품종류 및 농도 등이 적용되었다. 실험결과, 정수슬러지는 탄화나 약품첨착과정을 통해 커다란 성능 향상이 이뤄짐을 알 수 있었다.
        4,000원
        1258.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        올레핀/파라핀 혼합 기체의 분리를 위한 올레핀 촉진 수송 분리막의 제조를 위해 amide 작용기를 가지며 glassy한 특성을 보이는 polyvinylpyrrolidone (PVP) 고분자를 분리막의 matrix로서 사용하였다. 분리막의 기체 투과 실험은 propylene 과 propane 50 : 50의 부피비로 혼합된 기체를 사용하였고, bubble meter와 gas chromatography를 사용해 투과도와 선택도를 측정하였다. 또한 SEM image와 FT-IR을 통해 막의 특성을 조사하였다. 100시간의 장시간 성능 측정 결과 선택도는 약 15, 투과도는 약 1.3 GPU 이상을 각각 유지하였다. 기존의 poly(2-ethyl-2-oxazoline) (POZ)/AgBF4/Al(NO3)3 분리막과 비교함으 로써, 고분자 matrix로서의 PVP 특성을 확인하였다.
        4,000원
        1259.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        폴리카프로락톤(PCL)에 NaCl을 혼합한 용액을 블레이드법에 의하여 막형태로 제조한 후 NaCl을 추출하는 염출 법을 이용하여 조직공학적으로 사용할 3차원 다공망을 갖는 멤브레인 형태의 지지체를 제조하였다. 본 연구에서는 성형된 멤 브레인의 건조조건과, NaCl 입자의 크기, NaCl의 혼합량을 각각 다르게 하여 제조하였다. 별도로 제작한 고분자용액 공급장 치를 이용하여 PCL/클로로포름(CHCl3) 용액에 NaCl 입자가 균일하게 혼합된 용액을 유리판에 분주하여 필름 어플리케이터 를 사용하여 블레이드법에 의한 멤브레인을 제조하였다. 멤브레인 지지체에는 NaCl 입자에 의한 거대기공과 거대기공을 이 루는 구조벽에서는 CHCl3의 증발에 의한 미세기공이 함께 복합적으로 상호 연결되어 형성되었다.
        4,000원
        1260.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The microstructural properties and electrical characteristics of sputtering films deposited with a Cu-Ga target are analyzed. The Cu-Ga target is prepared using the cold spray process and shows generally uniform composition distributions, as suggested by secondary ion mass spectrometer (SIMS) data. Characteristics of the sputtered Cu-Ga films are investigated at three positions (top, center and bottom) of the Cu-Ga target by X-ray diffraction (XRD), SIMS, 4-point probe and transmission electron microscopy (TEM) analysis methods. The results show that the Cu-Ga films are composed of hexagonal and unknown phases, and they have similar distributions of composition and resistivity at the top, center, and bottom regions of the Cu-Ga target. It demonstrates that these films have uniform properties regardless of the position on the Cu-Ga target. In conclusion, the cold spray process is expected to be a useful method for preparing sputter targets.
        4,000원