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        검색결과 226

        81.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ensemble classification involves combining individually trained classifiers to yield more accurate prediction, compared with individual models. Ensemble techniques are very useful for improving the generalization ability of classifiers. The random subspace ensemble technique is a simple but effective method for constructing ensemble classifiers; it involves randomly drawing some of the features from each classifier in the ensemble. The instance selection technique involves selecting critical instances while deleting and removing irrelevant and noisy instances from the original dataset. The instance selection and random subspace methods are both well known in the field of data mining and have proven to be very effective in many applications. However, few studies have focused on integrating the instance selection and random subspace methods. Therefore, this study proposed a new hybrid ensemble model that integrates instance selection and random subspace techniques using genetic algorithms (GAs) to improve the performance of a random subspace ensemble model. GAs are used to select optimal (or near optimal) instances, which are used as input data for the random subspace ensemble model. The proposed model was applied to both Kaggle credit data and corporate credit data, and the results were compared with those of other models to investigate performance in terms of classification accuracy, levels of diversity, and average classification rates of base classifiers in the ensemble. The experimental results demonstrated that the proposed model outperformed other models including the single model, the instance selection model, and the original random subspace ensemble model.
        4,200원
        82.
        2016.02 구독 인증기관 무료, 개인회원 유료
        This study was carried out to improve the performance of sewer trenchless entire repair method by using the multifunctional safety high-pressure hose. Because the flexural strength and flexing modulus of elasticity increased in the range from 60℃ to 80℃ of the setting temperature, the unform quality was secured to satisfy the standard quality and consolidate the strength, by supplying steam to the entire sewer through the safety high-pressure hose simultaneously. After the steam was supplied, the temperature of the condensate water with a large amount occurred , compared with a small amount, was very low. So, the setting time was shorter over than one hour by reducing the unsatisfied cure state and excluding the condensate water. The standard quality increased by approximately 15% at upper, central, and lower points of the same sewer was gained from the test result of CIPP(cured in place pipes) constructed at the optimum setting temperature. The steam and air were supplied evenly to the sewer by controlling the safety high-pressure hose in the tense and relaxed state and by using the exclusive function of condensate water. The availability and safety for the constructed process were achieved.
        4,000원
        84.
        2015.11 구독 인증기관·개인회원 무료
        이 연구의 목적은 폴리머 자체의 개질을 통하여 막증류 법에 사용되는 막의 소수성 향상으로 막의 젖음 현상을 줄이는 것을 목표로 한다. 막의 소수성을 향상시키기 위해, 현재 일반적으로 쓰이는 폴리머(PVC, PVDF 등)에 소수성을 향상 시켜줄 수 있는 branch를 붙이는 방법으로 개질을 한다. Branch로는 styrene, pentafluorostyrene 등을 ATRP(atom transfer radical polimerization)를 통해 폴리머를 합성하고 ft-ir로 성공적으로 개질한 것을 확인하였다. 그 후, 평막 형태로 제막하여 접촉각을 측정해 소수성을 평가하는 것으로 폴리머의 소수성 향상 여부를 확인하였다.
        85.
        2015.10 구독 인증기관 무료, 개인회원 유료
        This paper considers a paternity and kinship analysis system(PKAS) being currently used in real sites. A knowledge-based expert system is proposed to improve the performance of PKAS in terms of accuracy, speed, training time, and satisfaction, which are common measures for evaluation. The knowledge base, one of the most important components in the knowledge-based expert system(KBES), consists of a rule made from random matching algorithm, decision rules of allele types and guide rules of options. The last two rules are learning incrementally from sample data. The results show that PKAS armed with the expert system ensures the better performance with regard to these criteria than the existing system. Especially as far as speed is concerned, as the sample size increases, it outperforms the existing one. As the number of samples increases, while processing time increases nearly exponentially in the existing PKAS, it does linearly in our proposed system.
        4,000원
        88.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we developed the hydraulic leveling jack(HLJ) with double-tube type structure which could be applicable to excessive lateral load area. In order to develop HLJ, the design requirements, such as the vertical and lateral loads where applied to hydraulic jack, were selected. To verify the structural stability of the HLJ, the structure analysis was performed. In order to verify the operational performance and structural stability of the developed HLJ, test bench was designed. The performance of HLJ was verified via various test using test bench.
        4,000원
        89.
        2015.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents the performance improvement of an EQS (Eradic Quake System) device applied to a nuclear power plant. For the nuclear facility, the EQS device needs to be ensured to have high quality, flexibility of design and reliability. To improve the reliability of the design, the hysteresis of the device must be exactly predicted. The friction coefficient of PTFE (PolyTetraFluoroEthylene) and the stiffness of the MER-Spring are considered as the factors influencing the hysteresis curve. In this paper, those factors are analysed to predict the behavior of the device and to improve the equipment of the EQS device. The results of the improved EQS device have been verified via a tests to be comparable with the predicted results. The estimation results indicate that considering those factors is more appropriate than the results of the previous design and method.
        4,000원
        90.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the ventilation of duct is simulated by CFD and thermal changes on the seat surface are measured experimentally. These models are the improved duct and the existing one installed at the real seat in order to test the thermal change 1 minute later. The seat with the existing duct has the temperatures of 26℃ and 25℃ on lumber and femoral parts respectively. However, the seat with the improved duct has the temperature of 1℃ lower than the seat with the existing duct. This result contributes to develop the improved duct. Hereafter, the methods used in this study are expected to be useful at checking the flow resistance loss of the ventilation seat duct and assessing the flow channel design
        4,000원
        92.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Performance based design(PBD) is the method to make a fire safety design against them after predicting the factors of fire risk in a building. Therefore, predicting fire risk in a building is very important process in PBD. For predicting fire risk of a building, an engineer of PBD must consider various factors such as ignition location, ignition point, ignition source, first ignited item, second ignited item, flash over, the state of door and fire suppression system. But, it is difficult to trust fire safety capacity of the design because the process in Korea' PBD is unprofessional and unreasonable. This paper had surveyed some cases of PBD that had been made in Korea to find the problems of the process to predict fire risk. And it have proposed the improvements of process to predict fire risk of a building.
        4,000원
        93.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ozonation process has been widely used for drinking water disinfection around the world. Recently, the pressurized ozone contactor, in which the side stream typed ozone injection method is installed, has been applied to water treatment system. In this study, numerical calculations were conducted to compare prototype and screw-type ozone contactors based on hydraulic effectiveness in more details. The prototype ozone contactor was already installed and operated in domestic water treatment plant, and the screw-type is the suggested one for improving ozone contact efficiency installing the screw plate to the prototype. Screw turn numbers of screw plate were changed as 3, 5, 7 and 9, respectively for numerical simulation. The CT(concentration of disinfectant in mg/L times time in minutes) value was considered as one of the options for evaluating disinfection ability. From the results, it could be concluded that the performance of the screw-type is higher than that of the protype contactor by controlling the variable T as the tracer time. Also, Morill index of the screw-type(turn numbers = 5 ) appeared to be lower than the other.
        4,000원
        94.
        2014.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Commercial activated-carbon used as the electrode material of an electric double-layer capacitor (EDLC) was posttreated with various acids and alkalis to increase its capacitance. The carbon samples prepared were then heat-treated in order to control the amount of acidic functional groups formed by the acid treatments. Coin-type EDLC cells with two symmetric carbon electrodes were assembled using the prepared carbon materials and an organic electrolyte. The electrochemical performance of the EDLC was measured by galvanostatic charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. Among the various activated carbons, the carbon electrodes (CSsb800) prepared by the treatments of coconutshell-based carbon activated with NaOH and H3BO5, and then heat treated at 800˚C under a flow of nitrogen gas, showed relatively good electrochemical performance. Although the specific-surface-area of the carbon-electrode material (1,096m2/g) was less than that of pristine activated-carbon (1,122m2/g), the meso-pore volume increased after the combined chemical and heat treatments. The specific capacitance of the EDLC increased from 59.6 to 74.8 F/g (26%) after those post treatments. The equivalent series resistance of EDLC using CSsb800 as electrode was much lower than that of EDLC using pristine activated carbon. Therefore, CSsb800 exhibited superior electrochemical performance at high scan rates due to its low internal resistance.
        4,000원
        97.
        2013.10 구독 인증기관 무료, 개인회원 유료
        Hanok is the key technology of the 21st century buzzword, as 'healthy homes' and 'eco-friendly' and to meet the demands for the safety and comfort of the human body in space, the possibility is getting attention again. Hanok worth from the perspective of brand marketing, pay raises, and maintain it throughout the whole life cycle of the value based on continuous activities. The systematization, and the efficiency of the way should be carried out to maintain to achieve the purpose. This presented study is divided into three stages, the consideration of Hanok Characteristics, maintenance manual written case analysis and Hanok written direction of the manual and take advantage of the possibilities. Firstly, for the consideration of Hanok natures, we study the Hanok maintenance characteristics to analyze the use of materials and construct method based on the result of 'Hanok technology development'. Secondly, we grasp the element which can be applied on the maintenance manual, analyze the maintenance manual contents and the written direction. Lastly, proposed step of written direction, we suggest the direction of Hanok manual writing based on identified elements.
        4,000원
        98.
        2013.05 구독 인증기관 무료, 개인회원 유료
        The goal of this study is optimization of transparency liquid chemical coating process. At coating process in the maintenance of the coating gap is an important factor. Specially, at a small split from the substrate using the existing methods is difficult to maintain the uniformity of coating. In this study, slit coating uniformity and compare inkjet uniformity and thickness profile was analyzed using alpha-step. Also, the pencil hardness test and the color difference measurement were performed. As a result, changes of the coating process need to be made depending on the type of substrate and inkjet coating was suitable for substrate of a small split.
        4,000원
        99.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 선박의 중앙집중 공조시스템에 공랭식 에어컨을 직접 설치하여 열원의 성능개선과 거주 구역별 독립 냉 난방이 가능한 개별분산 공조시스템을 하고자 하는 것이다. 연구 결과 기존의 중앙집중방식 공조시스템에 비해 열원 제어와 열효율상의 문제점을 보완함과 동시에 장치의 효율을 향상시킴을 확인하였다. 또한 동일한 조건에서 장치의 냉동능력과 성능계수는 평균 약 3 %, 23~26 % 정도 높게 나타났으며, Chilled Water Plants의 압축기 소비동력은 약 12 % 정도 낮게 나타났고, 동일한 조건에서 난방 시 소비동력은 약 33.5 % 낮게 나타났다. 따라서 공랭식 에어컨을 이용한 개별분산 공조시스템이 열원 제어뿐만 아니라 장치의 성능향상과 거주구역별 쾌적한 온 습도 환경 조성에 크게 기여하는 결과를 얻을 수 있었다.
        4,000원
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