검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 270

        101.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Using a progressive die of the multi-stage drawing product, It was experiments for the Influence of the Products Roundness on the die pad process Safety die model, obstacle countermeasure research safety die design When the die pad is independent structure, Sidewall thickness of the inside 2stage, 3stage, 4stage of the product is thicker, the thickness of the inside 1stage and the bottom is thinner. it was become unstable beacuse the inside 1stage related to the Products Roundness is thinner. When the die pad is Integrated structure, Sidewall thickness of the inside 1stage, 2stage of the product is thicker, and Sidewall 3stage and 4stage was a thin. it was become unstable beacuse the inside 3stage related to the Products Roundness is thinner. Therefore, The appropriate combination of and integrated independent is required for each process.
        4,000원
        102.
        2015.05 구독 인증기관·개인회원 무료
        The Chlor-alkali (CA) process is a representative electrolysis system to produce valued chemicals such as chlorine gas and sodium hydroxide. Membrane cell process has been obtaining the largest market shares, because it is free from environmental issues and low chemicals purity. For the CA process, commercially available membrane materials are perfluorinated sulfonic acid ionomers (PFSAs) with high chemical resistance. Unfortunately, there are limited data associated with the relationships between membrane material parameters and CA performances. It prevents the CA membrane development to be difficult. In this study, the influences of PFSA membrane thickness are disclosed, considering their ion transport behaviors, gas evolution capability, and chemical/electrochemical resistances under CA operation conditions.
        103.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The expansion of the display market could mass-produce the product which becomes the super-slim and ultra-lighting according to the demand of customer. This change etched the mobile display panel in order to make the thin glass. The wet etching refers to the process of removing selectively the unnecessary part in order to form the circuit pattern among the semi-conductor or the LCD manufacturing process. The wet etching can progress the etching about a large amount at a time but the thickness of glass is not smooth or not etched according to the process condition. In this study, the defect factor in the etching process tries to be analyze. The experimental design was established and the processing condition was optimized in order to minimize under non-etch part generation by the experiment of design.
        4,000원
        104.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        등숙 시기와 이삭 내 위치에 따른 과피 두께 및 립중의 변화를 조사 이들 간의 상관관계를 분석한 결과는 다음과 같다. 등숙 시기별 과피 두께의 변화는 없는 것으로 확인되었다. 따라서 과피 두께는 수정 후 18일 전에 결정되는 것으로 판단되며 식미가 우수한 찰옥수수 품종 육성을 위한 과피 두께 조사는 풋이삭 수확 적기뿐 만 아니라 이 그 후에 실시하여도 풋이삭 수확 적기와 동일한 관측치를 획득할 수 있을 것이라 판단된다. 립중은 최초 조사기인 수정 후 18일에서부터 계속 증가하다가 35일경 이후 부터는 비슷한 무게를 유지하였으며 등숙 시기별 과피 두께의 변화와는 통계적 상관 관계가 없는 것으로 확인되었다. 따라서 전분 축적과 종자의 성숙을 통한 종자 부피의 증가와 과피 두께 변화는 서로 연관성이 없는 것으로 판단된다. 이삭 내 위치에 따라 하부에서 상부로 갈수록 과피 두께 및 립중의 평균은 감소하는 경향이었으며 이들의 표준편차는 중앙부에서 안정되고 작게 조사되었다. 또한 이삭 내 위치에 따른 과피 두께 및 립중의 평균간에는 두 품종 모두 정의 상관 관계가 있음을 확인하였다. 이로서 찰옥수수 품종 육성과정에서 과피 두께를 위한 시료의 채취는 이삭 중앙부로부터 샘플을 취하는 것이 변이가 적고 평균적인 관측치를 얻을 수 있을 것으로 기대된다.
        4,000원
        105.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Other countries(USA, Europe) have performed the fire resistance design of buildings by the alternative performance design methods, which are based on fire engineering theories. However, in Korea, the process on the alternative fire resistance performance design has only suggested without any applications for real steel structures. Therefore, In the case of steel structures stagnant research on refractory measures face difficulties in introducing fire resistance design. In this study, first of all, Intumescent paint was analyze the thermal properties(thermal conductivity, specific heat and density). In Sequence, using the section factor by H-standard section propose of section concrete filled steel tube and hollow. finally presents a reasonable thickness Intumescent paint takes time to target performance of the proposed cross-section steel tube.
        4,000원
        106.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Impaired respiratory function is common in patients with stroke. The purpose of this study were to investigate the effectiveness of exercises and to assess forced vital capacity and peak cough flow after completion of neck stabilizing and respiratory reeducation exercises (combining diaphragmatic breathing and pursed-lip breathing exercises). The 45 participants were randomly assigned to an experimental group 1 (n1=15), experimental group 2 (n2=15), and a control group (n3=15). All subjects performed conservative physical therapy for 30 minutes. Experimental group 1 undertook the neck stabilizing exercise and the respiratory reeducation exercise. Experimental group 2 undertook the respiratory reeducation exercise. Additional exercise did not exceed 30 minutes, five times a week for six weeks. The subjects were assessed for deep neck flexor thickness and breathing function (forced vital capacity, forced expiratory volume at one second, forced expiratory volume at one second/forced vital capacity, peak expiratory flow, and manual assisted peak cough flow) at pre-post value. The results of this study were as follows. Experimental group 1 showed a significant increase only in deep neck flexor thickness change rate (p<.05). All groups showed significant increases in forced vital capacity, forced expiratory volume at one second, and peak expiratory flow in pre-post measurement (p<.05). Experimental groups 1 and 2 showed an increase in manual assisted peak cough flow in pre-post measurement (p<.05). There was no significant difference between experimental group 1 and experimental group 2, but experimental group 1 improved more than experimental group 2 in respiratory function as a whole. In conclusion, these findings suggest that the neck stabilizing exercise in combination with the respiratory reeducation exercise can improve forced vital capacity and peak cough flow in patients with stroke.
        4,200원
        107.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The honeycomb aluminum foam of the porous metal has the merit of the impact absorption, the soundproof, the heat conductivity, the light weight. Aluminum 6061-T6 is used at the materials for the automobile, the ship, the machine and various structures. In this study, the sandwich combined with the honeycomb aluminum foam and aluminum 6061-T6 is simulated with the impact. Two kinds of models made by use of CATIA program with 3 kinds of impact energies are analyzed by ANSYS program. As the simulation result, the maximum deformations at the cases of 1 and 2 are shown as 4.8205mm and 11.909mm respectively. And the maximum equivalent stresses at the cases of 1 and 2 are shown as 274.45MPa and 265.6MPa respectively. As the simulation result at case 1 approaches the experimental result, all simulation results can be verified in order to apply into analyzing the impact properties of the honeycomb aluminum foam sandwiches. In cases of three kinds of impact energies, the striker is not shown to penetrate the upper face sheets of case 1. At the impact energy of 100 J, the striker is not shown to penetrate the upper face sheets of case 2. At the impact energies of 200 J and 300 J, the striker is shown to penetrate the upper face sheets of case 2. It is thought to predict and improve the structural safety the composite material combined with the aluminium foam by using this study result.
        4,000원
        108.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The objective of this study is to evaluate the effectiveness of a geogrid reinforced subbase of permeable flexible pavement structures with respect to permanent deformation. METHODS : Experimental trials employing a repeated triaxial load test scheme were conducted for both a geogrid reinforced subbase material and a control specimen to obtain the permanent deformation properties based on the VESYS model. Along with this, a finite elementbased numerical analysis was conducted to predict pavement performance with respect to the rutting model incorporated into the analysis. RESULTS AND CONCLUSIONS: The results of the experimental study reveal that the geogrid reinforcement seems to be effective in mitigating permanent deformation of the subbase material. The permanent deformation was mostly achieved in the early stages of loading and then rapidly reached equilibrium as the number of load applications increased. The ultimate permanent deformation due to the geogrid reinforcement was about 1.5 times less than that of the control specimen. Numerical analysis showed that the permeable, flexible pavement structure with the geogrid reinforced subbase also exhibits less development of rutting throughout the service life. This reduction in rutting led to a 20% decrease in thickness of the subbase layer, which might be beneficial to reduce construction costs unless the structural adequacy is not ensured. In the near future, further verification must be conducted, both experimentally and numerically, to support these findings.
        4,000원
        109.
        2015.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, in order to improve the efficiency of n-type monocrystalline solar cells with an Alu cell structure, we investigate the effect of the amount of Al paste in thin n-type monocrystalline wafers with thicknesses of 120 μm, 130 μm, 140 μm. Formation of the Al doped p+ layer and wafer bowing occurred from the formation process of the Al back electrode was analyzed. Changing the amount of Al paste increased the thickness of the Al doped p+ layer, and sheet resistivity decreased; however, wafer bowing increased due to the thermal expansion coefficient between the Al paste and the c-Si wafer. With the application of 5.34 mg/cm2 of Al paste, wafer bowing in a thickness of 140 μm reached a maximum of 2.9 mm and wafer bowing in a thickness of 120 μm reached a maximum of 4 mm. The study’s results suggest that when considering uniformity and thickness of an Al doped p+ layer, sheet resistivity, and wafer bowing, the appropriate amount of Al paste for formation of the Al back electrode is 4.72 mg/cm2 in a wafer with a thickness of 120 μm.
        4,000원
        110.
        2014.12 구독 인증기관 무료, 개인회원 유료
        유기태양전지의 투명전극으로서 기존의 값비싸고 깨지기 쉬운 Indium Tin Oxide (ITO) 전극을 대체하고자, 전도성 고분자인 poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)를 적용하였다. 솔벤트의 도핑 농도에 따른 PEDOT:PSS 박막의 전기 전도도와 표면 거칠기의 특성 변화를 관찰하고, 그 결과가 PEDOT:PSS를 투명전극으로 사용한 유기태양전지의 특성에 미치는 영향을 연구하였다. PEDOT:PSS의 솔벤트 농도가 증가함에 따라, 박막의 표면 거칠기가 증가하고, 이는 유기태양전지의 단락전류의 변화를 야기했다. 또한, 소자의 홀 이동층이 얇아짐에 따라 광활성층의 단파장영역의 광흡수가 증가하는 것을 관찰할 수 있었다.
        4,000원
        111.
        2014.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Microstructural evolution in the thickness direction of an oxygen free copper processed by accumulative rollbonding (ARB) is investigated by electron back scatter diffraction (EBSD) measurement. For the ARB, two copper alloy sheets 1 mm thick, 30 mm wide and 300 mm long are first degreased and wire-brushed for sound bonding. The sheets are then stacked and roll-bonded by about 50% reduction rolling without lubrication at an ambient temperature. The bonded sheet is then cut to the two pieces of the same dimensions and the same procedure was repeated on the sheets up to eight cycles. The specimen after 1 cycle showed inhomogeneous microstructure in the thickness direction so that the grains near the surface were finer than those near the center. This inhomogeneity decreased with an increasing number of ARB cycles, and the grain sizes of the specimens after 3 cycles were almost identical. In addition, the aspect ratio of the grains decreased with an increasing number of ARB cycles due to the subdivision of the grains by shear deformation. The fraction of grains with high angle grain boundaries also increased with continuing process of the ARB so that it was higher than that of the low angle grain boundaries in specimens after 3 cycles. A discontinuous dynamic recrystallization occurred partially in specimens after 5 cycles.
        4,000원
        112.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 국내 선박해양플랜트연구소에 구축된 빙해수조의 빙특성 중에서 모형빙의 두께와 유효탄성계수 산출과정이 소개되었다. 수조에서 결빙되는 빙판은 크기가 가로 세로각각 30 m 정도에 두께는 40mm정도이다. 모형선의 실험결과를 쇄빙선 설계에 사용하기 위하여 빙 특성 정보가 필요하다. 사람이 빙판을 일부 절개하고 일일이 손으로 두께를 측정하는 것을 지양하기 위하여 초음파 기기를 사용하였는데 저주파 장비를 사용하여 작은 샘플 모형빙에 대한 두께는 계측되었다. 하지만 완벽한 계측을 위해서는 송수신 일체형 저주파 센서나 정확한 위치가 설정된 분리형 센서 혹은 고가의 특수 장치가 필요함을 확인하게 되었다. 한편 빙판의 처짐량을 간이식 LVDT로 계측하고 이를 탄성체 위에 놓인 무한 판의 특성길이 관계식에 대입하여 빙의 유효탄성계수를 산출하였는데 외국의 결과와 유사함이 입증되었다.
        4,000원
        113.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the activity of the transverse abdominal muscle resulting from changed posture by measuring the thickness of the transverse abdominal muscle in a supine posture, a slouched sitting posture, and an erect sitting posture. The subjects of the study were 28 patients with cerebral palsy. All their transverse abdominal muscles at the end of inhalation were measured at supine, slouched sitting (S sitting) and erect sitting (E sitting) postures by using ultrasonography, and then their dynamic sitting balance was measured at S sitting and E sitting postures by using BioRescue. For the statistical analysis, the Kruskal-Wallis test and the Wilcoxon signed-rank test were used to compare the differences among each the postures. The results were as follows. The thickness of the transverse abdominal muscle when comparing the supine posture and the S sitting posture showed no statistically significant difference. But the E sitting posture showed a statistically significant difference as compared with the others. In addition, the dynamic sitting balance in comparing the S sitting and E sitting postures showed a significant difference. In conclusion, the E sitting posture has a more positive effect on postural control and balance than generally taking the S sitting posture, for the sitting posture of a patient with cerebral palsy. It is suggested that patients with cerebral palsy mainly experiencing a sedentary life or being in a wheelchair should be seated in the E sitting posture during their daily life, and it may be necessary to continue to monitor and manage the proper E sitting posture.
        4,000원
        114.
        2014.06 구독 인증기관 무료, 개인회원 유료
        Background and Purpose: The Ankle-Brachial Index (ABI) is the ratio of blood pressure in the lower legs to that in the arms. The intima-media thickness (IMT) of extracranial carotid arteries determined by B-mode ultrasound is a measurable index of the presence of atherosclerosis. A low ABI and a high carotid IMT are independently related to increased risk of cardiovascular events. This study examined the association between carotid IMT and ABI in patients with ischemic stroke. Materials and Methods: Retrospectively, 116 hospitalized patients with ischemic stroke were recruited. Using a pulse wave velocity ABI device along with carotid duplex sonography, we measured carotid IMT and ABI and investigated the correlation between average values. Results: There was a significant difference in carotid IMT between the normal and abnormal ABI groups (P=0.0262). The group with an abnormal ABI was more than five times as likely to have increased carotid IMT as the group with a normal ABI (age, sex-adjusted OR 5.67 (95% CI 1.85~17.38)). The ABI and carotid IMT showed a weak inverse linear correlation in patients with ischemic stroke (correlation coefficient −0.378 after adjusting for age and sex). Conclusion: Our study suggests that an abnormal ABI is associated with a high carotid IMT in patients with ischemic stroke.
        3,000원
        115.
        2014.04 구독 인증기관·개인회원 무료
        Plates are frequently used in constructing nuclear power plant structures as a structural member. Creating holes in plates, complying with the function, may sometimes is needed. As the buckling may cause the plate to be failed, this study deals with investigating the effects of the thickness of the plate having through holes on its buckling. A range of thicknesses from 1mm to 10mm is considered for the plate to be investigated. Two holes of diameters of 10mm are created in the plate. The load having the magnitude of 1N/m is applied on the left edge of the plate. Both plates with and without holes are investigated. Results showed that thin plates can fail due to geometrical failure while thick plates may fail due to materials failure. The maximum difference in buckling load between the plate with hole and without hole has occurred for the plate having the thickness of 6mm.
        116.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to investigate the association between carotid artery calcification (CAC) on panoramic radiograph and intima-media thickeness (IMT) measured on ultrasound. Panoramic radiographs which were taken from dental patients aged 50 years and older who visited for dental treatment were screened for the presence of CAC. The study group was composed of seven patients (four males and three females, average age 74.4±4.2 yrs) with CAC detected on panoramic radiographs, and the control group eleven patients (seven males and four females, average age 64.5±10.1 yrs) without CAC. All the patients underwent carotid ultrasonography to measure carotid IMT. The IMT was compared between the groups by nonparametric analysis of covariance (ANCOVA). The range of IMT of the study group was 1.10~2.0 mm, while that of the control group 0.60~1.10 mm. The mean of IMT was 1.50±0.34 mm in the study group and 0.85±0.14 mm in the control group, and there was statistically significant difference between the two groups (p<.01). In conclusion, CAC detected on panoramic radiograph might have an association with atherosclerosis
        4,000원
        117.
        2014.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To realize high-performance thin film solar cells, we prepared CIGS by the co-evaporation technique on both sodalime and Corning glass substrates. The structural and efficient properties were investigated by varying the thickness of the Mo:Na layer, where the total thickness of the back contact was fixed at 1μm. As a result, when the Mo:Na thickness was 300 nm on soda-lime glass, the measured Na content was 0.28 %, the surface morphology was a plate-like compact structure, and the crystallinity by XRD showed a strong peak of (112) preferential orientation together with relatively intense (220) and (204) peaks as the secondary phases influenced crystal formation. In addition, the substrates on soda-lime glass effected the lowest surface roughness of 2.76 nm and the highest carrier density and short circuit current. Through the optimization of the Mo:Na layer, a solar conversion efficiency of 11.34% was achieved. When using the Corning glass, a rather low conversion efficiency of 9.59% was obtained. To determine the effects of the concentration of sodium and in order to develop a highefficiency solar cells, a very small amount of sodium was added to the soda lime glass substrate.
        4,000원