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        검색결과 1,080

        301.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Data clustering determines a group of patterns using similarity measure in a dataset and is one of the most important and difficult technique in data mining. Clustering can be formally considered as a particular kind of NP-hard grouping problem. K-means algorithm which is popular and efficient, is sensitive for initialization and has the possibility to be stuck in local optimum because of hill climbing clustering method. This method is also not computationally feasible in practice, especially for large datasets and large number of clusters. Therefore, we need a robust and efficient clustering algorithm to find the global optimum (not local optimum) especially when much data is collected from many IoT (Internet of Things) devices in these days. The objective of this paper is to propose new Hybrid Simulated Annealing (HSA) which is combined simulated annealing with K-means for non-hierarchical clustering of big data. Simulated annealing (SA) is useful for diversified search in large search space and K-means is useful for converged search in predetermined search space. Our proposed method can balance the intensification and diversification to find the global optimal solution in big data clustering. The performance of HSA is validated using Iris, Wine, Glass, and Vowel UCI machine learning repository datasets comparing to previous studies by experiment and analysis. Our proposed KSAK (K-means+SA+K-means) and SAK (SA+K-means) are better than KSA(K-means+SA), SA, and K-means in our simulations. Our method has significantly improved accuracy and efficiency to find the global optimal data clustering solution for complex, real time, and costly data mining process.
        4,000원
        304.
        2017.05 구독 인증기관 무료, 개인회원 유료
        Yoko Tawada’s drama Kafka Kaikoku (2013) depicts Japan’s encounter with Western culture from the Meiji era on as the catalyst for a metamorphosis much like Gregor Samsa’s in the work of the same name by Franz Kafka. Ironically, the victim of this East-West clash turns out to be Izumi Kyōka (1873-1939), a man who was anything but an enthusiastic adopter of European literary style. Interweaving elements also from Kafka’s Ein Landarzt (A Country Doctor, 1919), Tawada’s play suggests further that Izumi’s fate was set, since he—and, by extension, all Japanese—could not resist roles the West had prepared for him. Ultimately, this article explains, Kafka Kaikoku offers a critical view of modernization as a force that made Japanese into beings with a hybrid literary consciousness who lacked both much of their own native particularity and also their very humanity.
        6,000원
        305.
        2017.05 구독 인증기관·개인회원 무료
        Generally, fate of spematogonial stem cells (SSCs) can be determined specifically by microenvironments enclosed with various extracellular matrix (ECM) components and integrins recognizing directly ECM proteins play an pivotal role in transporting ECM-derived signals into cytoplasm, resulting in inducing a variety of biological functions such as cell attachment, self-renewal and differentiation. However, to date, studies on type of integrins expressed on the undifferentiated SSCs remain unclear. Therefore, we tried to investigate systematically what kind of integrin subunits are expressed transcriptionally or translationally in the SSCs derived from testis of hybrid B6CBAF1 mouse. For these, isolation of SSCs from testis were conducted by magnetic activated cell sorting (MACS) using Thy1 antibody. Subsequently, transcriptional and translational level of integrin α and β subunits in the isolated SSCs were measured by real-time PCR and fluorescene immunoassay, respectively. As the results, transcriptional levels of genes encoding total 25 integrin subunits were quantified, and integrin α4, α6, α7, α9, αV, αL and αE and integrin β1, β5 showed higher expression levels than other subunits. By contrast, integrin α3, α5, α 10 and α11 and integrin β2, β3, β4, β7 were weakly transcribed. When translational levels of the integrin α subunits showing high transcription level (α4, α6, α7, α9, αV αL, and αE) were measured, integrin α6, α7, α9, αV and αL were higher than integrin α4 and αE. In case of integrin β subunit, β1 evaluated more expression than β5. From these results, we speculate that the undifferentiated SSCs derived from hybrid B6CBAF1 mouse may express integrin α4β1, α6β1, α7β1, α9β1, αVβ1 and/or αVβ5 on plasma membrane. Moreover, this information will greatly contribute to constructing non-cellular niche supporting self-renewal of SSCs in the future.
        306.
        2017.05 구독 인증기관·개인회원 무료
        기존에 많이 이용되고 있는 전기탈이온(EDI) 공정은 전기투석법과 이온교환수지법을 혼합한 공정이다. 그리고 공정에 이용되는 모듈은 전기투석을 위한 양・음이온교환막이 있으며 두 막 사이에 이온교환수지로 채워지는 형태이다. 그리고 모듈의 성능을 결정하는 인자로는 이온교환수지의 균질한 크기 분포도가 있다. 하지만 이온교환수지와 양・음이온교환막으로 인해 모듈의 크기가 커지는 단점이 있다. 이러한 점들을 바탕으로 현재 이온교환수지를 글라인딩하여 bipolar 형태의 막으로 만든 electro-adsorption deionization(EAD) 공정 모듈이 생산되고 있다. 본 연구는 현재 생산되고 있는 모듈보다 높은 이온교환능력을 가지는 이온교환고분자를 합성하고, 이온교환수지을 대신할 이온교환그룹을 가진 nano particle 제조하여 이 둘을 적절하게 조절하여 하이브리드막을 제조하였다. 그리고 제조된 하이브리드막은 전기화학적, 열적, 기계적 특성평가를 실시하였고, 그에 따른 고찰을 진행하였다.
        307.
        2017.05 구독 인증기관·개인회원 무료
        이온교환막은 양이온 및 음이온을 선택적으로 분리할 수 있는 이온선택성을 지닌 막으로, 연료전지, 레독스전지, 전기투석, 역전기투석 등 다양한 분야에 응용되고 있다. 본 연구에서는 암모늄 및 비닐 그룹이 수식된 실란들과 솔-젤 법을 이용해 암모늄 그룹과 비닐 그룹을 동시에 지니는 올리고실록산 수지를 합성했고, 본 수지와 비닐 및 아크릴아마이드계 모노머 solution의 광라디칼 중합반응과 PE계 다공성 지지체를 활용해 실리콘-비닐 하이브리드 음이온교환막을 제조했다. 합성된 올리고실록산 수지는 FT-IR 및 29 Si NMR에 의해 분석되었고, 수지 내 실록산 결합이 성공적으로 형성되었음을 확인했다. 또한, 제조된 실리콘-비닐 하이브리드 음이온교환막은 swelling 후 약 20um 두께를 지니고 있었고, 0.6 Ω·cm² 이하의 저항, 85%의 permselectivity, 1.5 meq g-1 정도의 ion exchange capacity (IEC)를 지니고 있었다.
        308.
        2017.04 구독 인증기관·개인회원 무료
        GFRP(Glass Fiber Reinforced Polymer Plastic) has a superior corrosion resistance, high specific strength/stiffness, etc. Therefore, such properties can be used to mitigate the problems associated with the use of conventional construction materials. In this study, the various rib and pitch distance of hybrid fiber GFRP bars were evaluated by experimental method. From the test result, thirty two types of FRP hybrid bars such as spiral type with the dimension of rib geometry were fabricated. To evaluate the bond properties of them, direct pull-out test was performed. All testing procedures including specimen preparation, set-up of test equipment and measuring devices were made in accordance with the recommendations of ASTM D 7913. From the test results, it was found that cross type hybrid GFRP reinforcing bars showed the highest bond strength than that of the others due to the higher relative rib area.
        309.
        2017.04 구독 인증기관·개인회원 무료
        Tensile strength was investigated for hybrid bar (HYB), in this study. HYB is made of both steel reinforcement and glass fiber. Cross section of HYB has a shape in which steel reinforcement wrapped with glass fiber. For the production of HYB, rebar of SD400 class and glass fiber of E class are used as main materials. Vinyl ester resin is used to harden a glass fiber. In order to evaluate for tensile strength of HYB, the direct tensile test was performed about total ten specimens. The length of total specimens is 2,200 mm including the grip. Diameter of HYB according to core diameter was considered as a test variable. Direct tensile test for HYB was performed using a UTM with a capacity of maximum 1,000 kN. Tensile strength and strain were measured for each specimen during the test. From the test results, tensile strength and elastic modulus were 317 ~ 341 MPa, 103 ~ 107 GPa, respectively. Especially, elastic modulus of HYB was improved in comparison with usual GFRP bars such as the Aslan 100 or the V-rod.
        310.
        2017.04 구독 인증기관 무료, 개인회원 유료
        During the last two decades, fiber reinforced polymer (FRP) reinforcing bars for concrete structure have been extensively investigated and a number of FRP bars are commercially available. However, major shortcomings of the existing FRP bars are its high initial cost and low elastic modulus compared to conventional steel bars. Because of these reasons, Korea Institute of Civil Engineering and Building Technology (KICT) in Korea has developed the FRP Hybrid Bar which have the concept of material hybridization for concrete structures, especially for marine and waterfront concrete structures. This developed bar is new type material in construction field, verification of long term performance is very important for commercialization. In this paper, verification methodology on long term performance(corrosion, flexural behavior etc) of FRP Hybrid Bar is suggested.
        3,000원
        311.
        2017.04 구독 인증기관 무료, 개인회원 유료
        To overcome shortcomings of fiber reinforced polymer (FRP), a hybridized FRP rebar was developed by the authors. This hybrid bar herein called “FRP Hybrid Bar” was fabricated by adopting advantages from two different materials, including glass fiber reinforced polymer (GFRP). Corrosion resistant characteristics of FRP Hybrid Bar were evaluated and the test results were explained in this paper. The use of the alternative reinforcement could allow concrete structures to extend life-span, to save maintenance and repair costs, etc. if the FRP Hybrid Bar was applied to RC structures located in a very corrosive environment, such as marina or harbor areas.
        3,000원
        312.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        GFRP(Glass Fiber Reinforced Polymer Plastic) has a superior corrosion resistance, high specific strength/stiffness, etc. Therefore, such properties can be used to mitigate the problems associated with the use of conventional construction materials. In this study, the various rib and pitch distance of hybrid fiber GFRP bars were evaluated by experimental method. From the test result, thirty two types of FRP hybrid bars such as spiral and cross type with the dimension of rib geometry were fabricated. To evaluate the bond properties of them, direct pull-out test was performed. All testing procedures including specimen preparation, set-up of test equipment and measuring devices were made in accordance with the recommendations of ASTM D 7913. From the test results, it was found that cross type hybrid GFRP reinforcing bars showed the highest bond strength than that of the others due to the higher relative rib area.
        4,000원
        313.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고강도, 내약품성, 무독성, 내연소성의 장점을 가지고 있는 PVdF (polyvinylidene fluoride) 나노섬유로 기공이 0.4 μm 평막을 제조한 후, 부직포와 평막으로 나권형 모듈을 제작하였다. 용존유기물의 흡착 제거를 위한 입상 활성탄(GAC, granular activated carbon) 흡착 컬럼과 자체 제작한 나권형 모듈로 혼성 수처리 공정을 구성하였다. 카올린과 휴믹산으로 조 제한 모사 용액을 대상으로, 처리수를 재순환하는 경우와 배출하는 경우 각각 GAC 충진량의 영향을 알아보았다. 여과실험 후 물 역세를 하여 회복률과 여과저항을 계산하였다. 또한, 탁도와 UV254 흡광도를 측정하여 GAC의 흡착 효과를 고찰하였 다. 그 결과, 처리수를 재순환하는 경우와 배출하는 경우 모두 탁도 처리율에는 GAC 충진량의 영향이 없었다, 하지만 GAC 의 UV254 흡광도 처리율이 처리수를 순환하는 경우 0.7~3.6%이었는데, 처리수를 배출하는 경우 3.2-5.7%로 증가하였다. 처리 수를 순환하는 경우 GAC의 충진량이 증가함에 따라, 가역적 여과저항(Rr)과 비가역적 여과저항(Rir)은 감소하는 경향을 보였 다. 그러나 총여과저항(Rt)은 거의 일정하였고, 물 역세 회복률(Rb)은 다소 증가하는 경향을 보였다.
        4,000원
        314.
        2017.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Transparent organic-inorganic hybrid hard coating films were prepared by the addition of SiO2 or ZrO2, as an inorganic filler to improve the hardness property, filler was highly dispersed in the acrylic resin. To improve the compatibility in the acrylic resin, SiO2 or ZrO2 is surface-modified using various silanes with variation of the modification time and silane content. Depending on the content and kind of the modified inorganic oxide, transparent modified inorganic sols were formulated in acryl resin. Then, the sols were bar coated and cured on PET films to investigate the optical and mechanical properties. The optimized film, which has a modified ZrO2 content of 4 wt% markedly improved in terms of the hardness, haze, and transparency as compared to neat acrylate resin and acrylate resin containing modified SiO2 content of 8 wt%. Meanwhile, the low transparency and high haze of these films slowly appeared at SiO2 content above 10 wt% and ZrO2 content of 5 wt%, but the hardness values were maintained at 2H and 3H, respectively, in comparison with the HB of neat acrylate resin.
        4,000원
        315.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Compound logistics is a service aimed to enhance logistics efficiency by supporting that shippers and consigners jointly use logistics facilities. Many of these services have taken place both domestically and internationally, but the joint logistics services for e-commerce have not been spread yet, since the number of the parcels that the consigners transact business is usually small. As one of meaningful ways to improve utilization of compound logistics, we propose a brokerage service for shipper and consigners based on the hybrid recommendation system using very well-known classification and clustering methods. The existing recommendation system has drawn a relatively low satisfaction as it brought about one-to-one matches between consignors and logistics vendors in that such matching constrains choice range of the users to one-to-one matching each other. However, the implemented hybrid recommendation system based brokerage agent service system can provide multiple choice options to mutual users with descending ranks, which is a result of the recommendation considering transaction preferences of the users. In addition, we applied feature selection methods in order to avoid inducing a meaningless large size recommendation model and reduce a simple model. Finally, we implemented the hybrid recommendation system based brokerage agent service system that shippers and consigners can join, which is the system having capability previously described functions such as feature selection and recommendation. As a result, it turns out that the proposed hybrid recommendation based brokerage service system showed the enhanced efficiency with respect to logistics management, compared to the existing one by reporting two round simulation results.
        4,000원
        316.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pressure retarded osmosis (PRO) processes can be implemented on a number of water types, using different technologies and achieving various power outcomes. In this study, Sewage facility effluent was used for feed solution of PRO and synthetic NaCl water for draw solution. This study was conducted to investigate effect of water quality of pretreatment on power density and flux decline in PRO process. The results show that organic and particulate foulants have to be removed for more stable operation. Flourescence technique with EEM enables to investigate the chemical properties of aquatic organic matter by extracting spectral information. Humic/fulvic matters and soluble microbial by-products were analyzed as the most affecting factors on the PRO performance. As a result of analyzing the whole system based on the energy consumption of the unit process, specific energy consumption(SEC) of the applicable technology for PRO pre-treatment should be about 0.2 kWh/m3 or less.
        4,000원
        317.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Originally, most lilies for cut-flower were Asiatic and Oriental hybrids. These days, however, interspecific hybrid cultivars are reared worldwide and customers expect various flower types and colors. ‘Cream Bell’ cultivar is an interspecific OT hybrid (Oriental hybrid × Trumpet hybrid) bred at Chungnam-do ARES in 2013. In 2007, interspecific pollination by stigma cut-style of OT hybrid 'Yelloween' and Trumpet hybrid 'Pink Perfection' was conducted to foster the cultivar with flourishing growth, high resistibility to leaf burn and leaf blight. It went through seed culture, multiplication, and seedling from 2007 to 2010. Breeding hybrid evaluation showed that the quality of the hybrid is excellent. From 2011 to 2013, unheated vinyl house cultivation and cultivar registration were performed for characterization. The flower of this lily is clear cream and primrose in color, without spots. It has a width of 18.2 cm and the consistent large flower has a trumpet style, along with many inner and outer perianth overlap. The stem has an oatmeal color and mid-size leaves. Flowering time in the central district starts on the 27th June, which seems to be relatively early. The flower direction is oriented inflorescence and semi-upward, and the cultivar shows robustness to leaf burn and leaf blight. The bulb can be grown with stem and leaf after cutting the flower, as the plant is quite tall. Also, with the high rate of bulb growth, bulb production is convenient. Cut flower production is of high quality with only routine cultivation control (disease, insects, nutrient, and moisture).
        4,000원
        318.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fiber-reinforced polymer (FRP) bars have advantages as a construction material, including corrosion resistance, lightweight and high tensile strength. However, FRP rebars have shortcomings, such as low elastic modulus comparing to the steel rebar. With these reasons, FRP bars have not been widely used to reinforced-concrete (RC) structures. To overcome these shortcomings, the steel-hybrid GFRP rebars were developed by the authors at Korea Institute of Civil Engineering and Building Technology (KICT). Mechanical properties of the developed steel-hybrid GFRP rebars were experimentally evaluated through this study. Both tensile and bonding tests were conducted and the mechanical performance was investigated as well as corrosion resistance. As a result of all tests, elastic modulus, tensile strength and boding strength of the steel-hybrid GFRP rebars were all improved in comparison with fully GFRP rebars.
        4,000원
        319.
        2016.11 구독 인증기관·개인회원 무료
        본 연구에서는 SWRO공정의 Feed Dilution에 따른 SWRO Permeate Flow의 민감도 분석 및 Hybrid Module Design을 통한 개선방안을 검토하였다.
        320.
        2016.11 구독 인증기관·개인회원 무료
        본 연구는 RO 공정을 통한 해수담수화 플랜트의 에너지 저감을 위한 FO/RO hybrid pilot plant 실증 연구에 관한 것이다. 폐수처리 방류수를 이용하여 FO 공정을 통해 해수를 희석시키고, 희석된 해수는 RO 공정을 통해 담수를 생산하는 공정으로 폐수재이용과 저에너지 담수화를 목적으로 하였다. 이 공정은 RO 공정에 유입되는 해수의 염도가 낮아지기 때문에 담수화 에너지를 획기적으로 낮추는 것이 가능하다. 운전된 system은 유입수 기준 1ton/hr의 처리용량을 가 지는 FO/RO hybrid 공정으로 화력발전소 내의 해수담수화 설비내에서 운전하였다. 이를 통하여 기존 RO system 대비 약 20~30%정도의 에너지 소비 저감 효과 및 RO의 fouling 개선 효과가 있음을 확인하였다.