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        검색결과 4,563

        1601.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to fabricate the porous Al₂O₃ with dispersion of nano-sized Cu particles, freeze-drying of cam-phene/Al₂O₃ slurry and solution chemistry process using Cu-nitrate are introduced. Camphene slurries with 10vol% Al₂O₃ was frozen at -25˚C. Pores were generated by sublimation of the camphene during drying in air. The sinteredsamples at 1400 and 1500oC showed the same size of large pores which were aligned parallel to the sublimable vehiclesgrowth direction. However, the size of fine pores in the internal walls of large pores decreased with increase in sinteringtemperature. It was shown that Cu particles with the size of 100 nm were homogeneously dispersed on the surfaces ofthe large pores. Antibacterial test using fungus revealed that the porous Al₂O₃/1vol% Cu composite showed antifungalproperty due to the dispersion of Cu particles. The results are suggested that the porous composites with required porecharacteristics and functional property can be fabricated by freeze-drying process and addition of functional nano par-ticles by chemical method.
        4,000원
        1602.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to investigate the effects of process conditions on the quality characteristics of beef-bone broth inan attempt to improve the quality of ready-to-eat Gom-Tang. Cow soup bone (500g) was heated in water(1,500mL) at 121oC for 3 h to 15 h using an autoclave. In an examination of the physical characteristics of thebeef-bone broth, samples extracted after 3 h and 5 h were able to form a weak gel, whereas samples extracted atlater times appeared to lose their gel forming capability. Regardless of physical characteristics, crude protein andtotal amino acid content increased as the extraction time increased. The content ratio of glycine to crude protein of3.9 appears to be the limit for gel formation. The size distribution of microparticles and turbidity from floc forma-tion in the beef-bone broth were affected by the kind of salt present. Refined-salt produced smaller particle sizesand better turbidity compared with sea salt. Also, the particle size and the formation of aggregates increased withcalcium concentration. The optimum concentration of calcium was found to be less than 0.04%. Our results indicatethat control of extraction time and additives can enhance the quality of beef-bone broth.
        4,000원
        1603.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 아연공기전지용 분리막으로 사용하기 위한 다공성 막을 Polyethersulfone (PES) 용액의 상전이법을이용하여 제조하였다. 캐스팅 용액은 PES/polyvinylpyrrolidone(PVP)/N-methylpyrrolidone(NMP) 용액으로 그리고, 비용매는 물을 사용하여 분리막을 제조하였다. 제조된 분리막을 이용하여 아연공기전지를 제작하였다. 분리막의 모폴로지는 캐스팅 용액 내의 PES 및 PVP의 함량을 통해 조절하였다. 제조된 분리막의 기계적 특성, 이온전도도 및 모폴로지는 인장실험, im-pedance 실험 및 SEM을 이용하여 측정하였다. 아연공기전지의 성능은 current interrupt method (CIM)와 정전류 방전실험을통하여 측정하였다. 캐스팅 용액 내의 PES 함량이 증가함에 따라 기계적 강도는 증가한 반면 이온전도도는 감소하였다. 반면, 캐스팅 용액 내의 PVP 함량이 증가함에 따라 이온전도도는 증가하였지만 기계적 강도는 감소하였다. 이와 같은 이온전도도 경향의 아연공기전지 내에서의 효과는 current interrupt method와 정전류 방전실험에서 확인되었다. PES 함량이 높은 캐스팅 솔루션의 분리막으로 제조된 전지는 높은 IR 손실과 낮은 방전용량을 보였으며, PVP 함량이 높은 캐스팅 솔루션의 분리막으로 제조된 전지는 낮은 IR손실과 높은 방전용량을 보였다.
        4,000원
        1604.
        2014.02 구독 인증기관 무료, 개인회원 유료
        The object of this paper is investigate noise source at metal material product manufacturing plant and create noise map for predict noise. The plant is located close to a residential area, and residents noise exposure damage expected. Through this research 68 points noise sources were measured. And according to analysis result, 30 percent of noise sources are measured above 90dB(A). Based on this measurement results were create a noise map, and comparison between the predicted noise and the background noise. The noise maps were calculated by noise prediction software using measurement data, GIS data, ESRI SHP files and actual survey data. As a analysis result, metal material products manufacturing plants are will have an effect by noise on the nearby residential area.
        4,000원
        1605.
        2014.02 구독 인증기관 무료, 개인회원 유료
        A study on air bag filter for passenger car which is manufacturing preocess and method of very important one of the components. The manufacturing equipment consists of various component which nitting cam, nitting knife, rollers. The development target is weight reduction of metal filter, reduction of process.
        4,000원
        1606.
        2014.02 구독 인증기관 무료, 개인회원 유료
        In this study, a large modulus of elasticity of the titanium alloy in use, to create artificial hip stress shielding effect appears to reduce the head portion is excellent in the strength of Ti-6Al-4V, making bone pusher which requires low elastic modulus relative modulus of pure titanium grade 2, using a small two metal after welding by explosion welding hip was made. Explosion pressure welding by the welding region with respect to the mechanical properties and the tissue was observed.
        3,000원
        1607.
        2014.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Well-distributed ruthenium (Ru) nanoparticles decorated on porous carbon nanofibers (CNFs) were synthesized using an electrospinning method and a reduction method for use in high-performance elctrochemical capacitors. The formation mechanisms including structural, morphological, and chemical bonding properties are demonstrated by means of field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). To investigate the optimum amount of the Ru nanoparticles decorated on the porous CNFs, we controlled three different weight ratios (0 wt%, 20 wt%, and 40 wt%) of the Ru nanoparticles on the porous CNFs. For the case of 20 wt% Ru nanoparticles decorated on the porous CNFs, TEM results indicate that the Ru nanoparticles with ~2-4 nm size are uniformly distributed on the porous CNFs. In addition, 40 wt% Ru nanoparticles decorated on the porous CNFs exhibit agglomerated Ru nanoparticles, which causes low performance of electrodes in electrochemical capacitors. Thus, proper distribution of 20 wt% Ru nanoparticles decorated on the porous CNFs presents superior specific capacitance (~280.5 F/g at 10 mV/s) as compared to the 40 wt% Ru nanoparticles decorated on the porous CNFs and the only porous CNFs. This enhancement can be attributed to the synergistic effects of well-distributed Ru nanoparticles and porous CNF supports having high surface area.
        4,000원
        1608.
        2013.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Freeze drying of a porous Cu-Sn alloy with unidirectionally aligned pore channels was accomplished by using a composite powder of CuO-SnO2 and camphene. Camphene slurries with CuO-SnO2 content of 3, 5 and 10 vol% were prepared by mixing with a small amount of dispersant at 50˚C. Freezing of a slurry was done at -25˚C while the growth direction of the camphene was unidirectionally controlled. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green bodies were hydrogen-reduced at 650˚C and then were sintered at 650˚C and 750˚C for 1 h. XRD analysis revealed that the CuO-SnO2 powder was completely converted to Cu-Sn alloy without any reaction phases. The sintered samples showed large pores with an average size of above 100μm which were aligned parallel to the camphene growth direction. Also, the internal walls of the large pores had relatively small pores. The size of the large pores decreased with increasing CuO-SnO2 content due to the change of the degree of powder rearrangement in the slurry. The size of the small pores decreased with increase of the sintering temperature from 650˚C to 750˚C, while that of the large pores was unchanged. These results suggest that a porous alloy body with aligned large pores can be fabricated by a freeze-drying and hydrogen reduction process using oxide powders.
        4,000원
        1609.
        2013.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Tungsten oxide films were prepared by an electrochemical deposition method for use as the anode in rechargeable lithium batteries. Continuous potentiostatic deposition of the film led to numerous cracks of the deposits while pulsed deposition significantly suppressed crack generation and film delamination. In particular, a crack-free dense tungsten oxide film with a thickness of ca. 210 nm was successfully created by pulsed deposition. The thickness of tungsten oxide was linearly proportional to deposition time. Compositional and structural analyses revealed that the as-prepared deposit was amorphous tungsten oxide and the heat treatment transformed it into crystalline triclinic tungsten oxide. Both the as-prepared and heat-treated samples reacted reversibly with lithium as the anode for rechargeable lithium batteries. Typical peaks for the conversion processes of tungsten oxides were observed in cyclic voltammograms, and the reversibility of the heat-treated sample exceeded that of the as-prepared one. Consistently, the cycling stability of the heat-treated sample proved to be much better than that of the as-prepared one in a galvanostatic charge/discharge experiment. These results demonstrate the feasibility of using electrolytic tungsten oxide films as the anode in rechargeable lithium batteries. However, further works are still needed to make a dense film with higher thickness and improved cycling stability for its practical use.
        4,000원
        1610.
        2013.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Fe4[Fe(CN)6]3 coated on a mica or TiO2/mica surface as infrared reflective blue pigment was prepared by a hydrothermal method. Fe4[Fe(CN)6]3, used as coloring agent, was uniformly coated on mica or TiO2/mica under the optimized condition of a 1.2 : 1 weight ratio between iron(III) chloride hexahydrate and potassium ferrocyanidetrihydrate at the initial pH level of 4.5 at 70˚C. The infrared (IR)-reflective pigments were characterized by SEM, Zeta-potenial, FT-IR, and UV-VIS NIR spectrophotometry. Especially the CIE color coordinate and total solar reflectance(TSR) properties of the pigments were investigated in relation to variation of the coating and coated substrate thicknesses. Isolation-heat paint was prepared with 20 wt% blue pigments fully dispersed in acryl-urethane resin and several additives to coat the film uniformly. The films were also measured with CIE color coordinate, TSR, and the surface temperature was recorded by an isolation-heat measuring system. The pigments and films of Fe4[Fe(CN)6]3 coated on mica and TiO2/mica showed high TSR values compared with the TSR value of Fe4[Fe(CN)6]3 itself. According to the increase of TSR value, the property of isolation-heat is effective. To realize the optimal blue color, we applied the the pigment to TiO2 coated mica(TM(b)) which has blueish interference color. The pigment of Fe4[Fe(CN)6]3 coated on TM(b) shows a strong blue color compared with that of Fe4[Fe(CN)6]3 coated on TiO2/Mmca(TM(w)), which has a whitish interference color.
        4,000원
        1611.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study includes: the relationships between corporate entrepreneurship(innovation, proactiveness, risk-taking) and firm performance(non-financial performance, financial performance) and the mediating effect of the self-efficacy on the relationship between corporate entrepreneurship and firm performance. In order to verify the relationships and mediating effect, data were collected from 368 individuals in employees working in small and medium-sized firms at Gyeongnam region to test theoretical model and its hypotheses. All data collected from the survey were analyzed using with SPSS 18.0. This study reports findings as follows: first, the relationship between the corporate entrepreneurship(except innovation) and the employee's self-efficacy is positively related. Second, there was also a positive correlation between the employee's self-efficacy and firm performance. Third, the relationship between the corporate entrepreneurship and the non-financial performance is positively related. The relationship between the corporate entrepreneurship(except innovation) and the financial performance is positively related. Finally, the employee's self-efficacy played as a partial mediator on the relationship between risk-taking and firm performance. The employee's self-efficacy played as a fully mediator on the relationship between proactiveness and non-financial performance. The employee's self-efficacy played as a partial mediator on the relationship between proactiveness and financial performance. However, there was no empirical evidence for the mediating effect of employee's self-efficacy on the relationship innovation and firm performance. Based on these findings, the implications and the limitations of the study were presented including some directions for future studies.
        4,300원
        1612.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research examines the causal relationships between supervisor trust and organizational citizenship behavior(OCB) and the mediating role of organizational trust on OCB. Using the sample of 282 small and medium sized enterprises’ employees, this study analyzes three alternative hypotheses centered around supervisor trust, organizational trust, and OCB. The results show that supervisor trust has a strong positive effect on OCB. Second, organizational trust is positively related to OCB. Third, this research proves that partial mediating effects of organizational trust exist between supervisor trust(relational trust) and OCB(civic virtue, sportsmanship). Finally, this research proves that a full mediating effect of organizational trust exists between supervisor trust(calculative trust) and OCB(sportsmanship). This study recommends supervisor trust, organizational trust be valued in order to increase OCB vital for organizational effectiveness or productivity in small-medium sized manufacturing enterprises.
        4,600원
        1613.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Microbial fermented cellulose gel, citrus gel(CG), was successfully fabricated to porousfoam by radiation treatment and freeze drying. The chemically induced radiation was used to createhighly porous foam and further freeze drying of the CG produced tough foams with interconnectedopen pores for use in tissue engineering. The microstructure of the CG foam was controlled byvarying the irradiation dose and quenching temperature with pore size ranging from several micronsto a few hundred microns. Tensile strength and Gurley value of the CG foam were influenced byirradiation dose. These radiation induced CG foams are promising scaffolds for tissue engineering.
        4,000원
        1614.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to present a case study of six sigma quality improvement practice in cooling fan motor(CFM) manufacturing processes. In this study, the CFM manufacturing process of automobile parts not relevant to the target process rate of the process point of view, in order to reduce the system to solve the problem of localized resolution procedures of six sigma DMAIC methodology was applied to study. In conclusion , this study 's field D in order to improve the initial rate of inadequate quality management best practices by applying the method of Six Sigma quality CFM failure through stabilization schemes were proposed cost reduction .To be CFM product to satisfy customers based on continuous monitoring of the effective field of claims quality management system is required.
        4,000원
        1615.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As companies were concerned with developing green logistics and environment, most logistics concerned functions like packaging, loading, storage, transportation and IT studies are active in study. Even if active in research studies, companies still recognized that logistics cost increases as green concepts are applied. For the efficient execution of green logistics management, it is absolutely necessary but difficult to build an optimal logistics system where each function is smoothly interacted through the proper integration and the link of various logistics functions and partners. This study aims to development of green logistics through integration of supply chain functions and partners. With this aim of study, case studies with analysis of embodiment, planning and operations for supply chain of companies are carried out.
        4,200원
        1616.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyurethane is an elastomer polymer, which is flexible, tough and resistant. This material is widely used various fields such as automobile, aeroplane, textiles, construction industries. Currently there exists more than 1,000 manufacturing companies in Korea that are closely related to Polyurethane. In spite of a number of Polyurethane manufacturing companies, there are little attention in academia as well as industries to study the safety and manufacturing process improvement on Polyurethane. In this paper, we consider a case study for the Polyurethane manufacturer to improve productivity by using safety management and manufacturing process reengineering. After careful analysis, we derive three enhancements to increasing the safety and productivity for the target company. Especially, we achieve about 16% productivity improvement in roller manufacturing process by replacing manual stirring job with automated mixing machine.
        4,300원
        1617.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to figure out the impacts of technological innovation and cost management on productivity in small shipping industries to come up with developmental implications. To achieve this, a survey was carried out to 150 workers in small shipbuilding industries through April 2 to April 20, 2012. As for findings stated above, technological innovation and cost management in the Korean small shipbuilding industries were key factors that elevate financial and non-financial productivity. In the light of low technological prowess and cost structure of small shipbuilding industries, their productivity can be improved when intensive cost management with production factor technology as know-how is realized through quality management, which product development technology is the top priority as an independent niche strategy. Consequently, the combination of infrastructures in small shipbuilding industries with continuous efforts for cost reduction by the link to the systematized structure can't only secure their independent competitiveness, but raise their productivity.
        4,000원
        1618.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The object of this paper is to examine the noise generating mechanism at manufacturing process of metal material products. To accomplish the object; A noise generating mechanism of high noise machine, which is mounted in the small and medium size enterprise, was investigated. The measurement method of the noise for the machine by manufacturers were investigated. The noise at the 250 points of the manufacturing process machine in the 40 processes of the 3 factories, 3 business fields was measured. The database of the noise was built from the measurement data. The major sound sources and frequency range for the manufacturing process of metal material product machine was investigated.
        4,000원
        1619.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The bio reactors with high efficiency using ejector are widely used in gas-liquid system, This is also due to the high efficiency in gas dispersion resulting in high mass transfer rate and low power requirements. Thus, the new liquid fertilizer manufacturing equipment composed with aeration tank, cycling tank and circulation pump using an ejector was developed. The aim of this study is to investigate the effect of an ejector on the liquid fertilizer manufacturing equipment and to design the optimal ejector for actual application using CFD analysis and experimental method. The results show that the suction air mass flow rate is increased, as the diameter of driving ejector nozzle is smaller and the position of nozzle is toward the exit of an ejector.
        4,000원
        1620.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        메밀 속성 장 프리믹스의 최적 조건을 확립하고자 품질특 성을 조사하였다. 소금량(8, 10, 12%)에 따른 품질특성 결과, 대장균 군수는 소금량 10, 12%(21일), 8%(28일) 이후로 검출 되지 않았으며, B. subtilis HJ18-4를 starter로 첨가한 군은 발 효 7일부터 검출되지 않았다. 아미노태 질소 함량은 21일까 지 급격히 증가하였으며, 그 후로 완만히 증가하였다. 그 결 과, 소금 함량 10%, starter 첨가 시 보다 안전한 발효가 이루어 졌다. 가수량(1:1, 1:1.5. 1:1.8)의 따른 품질특성 결과, 총균수 와 아미노태 질소 함량은 가수량이 적을수록 높았으며, 1:1 혼 합(35일)일 때 아미노태 질소 함량은 169.5 ㎎%로 가장 높았 고, 발효 28일 이후 대장균 군이 검출되지 않았다. 용기별(항 아리, 유리, 플라스틱)의 품질특성 결과, 총균수와 아미노태 질 소 함량은 유리 용기 대비 플라스틱과 항아리 용기가 높았으 며, 대장균군도 보다 빨리 감소하였다. Batch size(1.25 ㎏, 2.5 ㎏)를 달리하여 제조된 메밀 속성 장의 품질특성 결과, 총균수와 아미노태 질소 함량은 batch size에 따른 큰 차이가 없었으 며, 대장균 군 측정 결과, 14일째 2.5 ㎏(3.00×102 CFU/g), 1.25 g (1.25×103 CFU/g)으로 나타났다. 메밀 속성 장 프리믹스의 최적 조건은 가수량 1:1, 소금의 양 10%, B. subtilis HJ-18-4를 starter로 첨가, 항아리 및 플라스틱 용기는 3주, 유리 용기는 4주 발효시키는 것이 바람직하였다.
        4,000원