검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 249

        41.
        2018.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Existing reinforced concrete building structures have seismic vulnerabilities under successive earthquakes (or mainshock-aftershock sequences) due to their inadequate column detailing, which leads to shear failure in the columns. To improve the shear capacity and ductility of the shear-critical columns, a fiber-reinforced polymer jacketing system has been widely used for seismic retrofit and repair. This study proposed a numerical modeling technique for damaged reinforced concrete columns repaired using the fiber-reinforced polymer jacketing system and validated the numerical responses with past experimental results. The column model well captured the experimental results in terms of lateral forces, stiffness, energy dissipation and failure modes. The proposed column modeling method enables to predict post-repair effects on structures initially damaged by mainshock.
        4,000원
        43.
        2018.05 구독 인증기관·개인회원 무료
        최적화 분야에서는 VRP(Vehicle Routing Problem)에 대한 많은 연구가 오래전부터 이루어져 왔다. 기본적인 VRP 모형을 확장하여, 단일차고지와 다수차고지 특성, Pickup and Delivery 특성, Time Windows 특성 등을 고려하여 다양한 모형들을 도출되고 있으며 이들에 대한 보다 나은 해를 구하는데 초점이 맞추어져 왔다. 이들 VRP 모형들은 노드 수의 증가에 따른 NP-Hard 특성을 가지고 있기 때문에 최적화에 초점을 맞추기 보다는 Genetic Algorithms, Tabu Search, Simulated Annealing 등의 메타휴리스틱 기법 등을 이용하여 적용할 수 있는 우수한 해를 도출하려 노력을 기울이고 있다. 본 연구에서는 시간제약을 가지는 Multi-Depot Pickup and Delivery 모형을 이용하여 3자물류 기업에서 물류 트럭의 할당 및 이들에 대한 운영 상황 모니터링을 지원할 수 있는 시스템 개발에 초점을 맞추고 있다. 본 연구에서는 먼저 수요기업의 요구사항을 반영하여 가장 중점을 두고자 하는 혼적이 가능하고 시간제약을 반영한 해를 도출하고자 했으며 도출된 해를 기반으로 물류를 트럭에 할당한 후 물류 트럭에 대한 GPS기반의 모니터링 시스템을 제안하고자 한다.
        44.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Structure behaviors resulting from an earthquake are experimentally simulated mainly through a shaking table test. As for large-scale structures, however, size effects over a miniature may make it difficult to assess actual behaviors properly. To address this problem, research on the hybrid simulation is being conducted actively. This method is to implement numerical analysis on framework members that affect the general behavior of the structure dominantly through an actual scale experiment and on the rest parts by applying the substructuring technique. However, existing studies on hybrid simulation focus mainly on Slow experimental methods, which are disadvantageous in that it is unable to assess behaviors close to the actual level if material properties change depending on the speed or the influence of inertial force is significant. The present study aims to establish a Real-time hybrid simulation system capable of excitation based on the actual time history and to verify its performance and applicability. The hybrid simulation system built up in this study utilizes the ATS Compensator system, CR integrator, etc. in order to make the target displacement the same with the measured displacement on the basis of MATLAB/Simulink. The target structure was a 2-span bridge and an RC pier to support it was produced as an experimental model in order for the shaking table test and Slow and Real-time hybrid simulations. Behaviors that result from the earthquake of El Centro were examined, and the results were analyzed comparatively. In comparison with the results of the shaking table test, the Real-time hybrid simulation produced more similar maximum displacement and vibration behaviors than the Slow hybrid simulation. Hence, it is thought that the Real-time hybrid simulation proposed in this study can be utilized usefully in seismic capacity assessment of structural systems such as RC pier that are highly non-linear and time-dependent.
        4,000원
        45.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to develop a method to optimize residual chlorine concentrations in the process of providing water supply. To this end, this study developed a model capable of optimizing the chlorine input into the clearwell in the purification plant and the optimal installation location of rechlorination facilities, and chlorine input. This study applied genetic algorithms finding the optimal point with appropriate residual chlorine concentrations and deriving a cost-optimal solution. The developed model was applied to SN purification plant supply area. As a result, it was possible to meet the target residual chlorine concentration with the minimum cost. Also, the optimal operation method in target area according to the water temperature and volume of supply was suggested. On the basis of the results, this study derived the most economical operational method of coping with water pollution in the process of providing water supply and satisfying the service level required by consumers in the aspects of cost effectiveness. It is considered possible to appropriately respond to increasing service level required by consumers in the future and to use the study results to establish an operational management plan in a short-term perspective.
        4,200원
        47.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper suggests a specific model that could efficiently improve the interaction and the interface between MES(Manufacturing Execution System) server and POP(Point of Production) terminal through electronic document server and electronic pen, bluetooth receiver and form paper in disassembly and process inspection works. The proposed model shows that the new method by electronic document automation system can more efficiently perform to reduce processing time for maintenance work, compared with the current approach by handwritten processing system. It is noted in case of the method by electronic document automation system that the effects of proposed model are as follows; (a) While the processing time per equipment for maintenance by the current method was 300 minutes, the processing time by the new method was 50 minutes. (b) While the processing error ratio by the current method was 20%, the error ratio by the new method was 1%.
        4,000원
        48.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is necessary to monitor growth status of the crops due to continuous change of climate causing insecurity in crop cultivation. Low altitude remote sensing(LARS) system is utilized to accurately monitor the growth status of the crops. In this study, models for monitoring fresh weight(FW), one of the major growth factors of Chinese cabbage, were developed with structural indices and simple ratio calculated from bands in remotely sensed canopies by NIR, RE(imaging sensor A) and multispec-4c sensors(imaging sensor B) equipped with fixed-wing UAV depending on vegetation stages of normal planting(NP) and delayed planting(DP) Chinese cabbages. In results of imaging sensor A, the estimation models using structural indices and simple ratio were divided into NP and DP due to different attribute of reflectance in canopies with changed environment condition depending on different planting dates. The estimation models using simple ratio calculated by red edge and visible bands of NP showed better performance than other models, but RMSE was high. The models using simple ratio calculated by same bands of DP were feasible to accurately estimate FW(R2 of more than 0.946 with RMSE of less than 169.5 g). In results of imaging sensor B, the estimation models using structural indices and simple ratio on DP were divided into low to intermediate FW and intermediate to high FW. As a result, estimation models of all structural indices and simple ratio in low to intermediate FW bands were advisable to estimate FW(R2 of more than 0.860 with RMSE of less than 104.7 g). Estimation models of those calculated by red edge and visible bands in intermediate to high FW were only possible to accurately estimate FW(R2 of more than 0.532 with RMSE of less than 400.7 g).
        4,300원
        50.
        2017.04 구독 인증기관·개인회원 무료
        For the development of processed food for hypoglcemia, it is important to construct model system to confirm factors that reduce the glycemic index in real food. This study was to investigate the relationship between the gel model system and real food the high amylose type of segoami using response surface methodology. The independent variables were concentration (X1; 10, 15, 20, 25, and 30%) and steaming time (X2; 30, 35, 40, 45, and 50 min). The predicted glycemic index (Y1) was analyzed as a dependent variable. The regression of pGI was 0.7343, indicating that the model fits the data well in the prediction test. The predict glycemic index of the gel was in the range of 71.38 ~ 83.78, depending on the gel preparation conditions and predicted optimum condition was 23.7% gel concentration and 43.8 minutes of gelatinization. The predict glycemic index of rice gel were decreased with an increase of gel concentration, rather than the steaming time. In order to confirm the effect on in vitro digestibility in real food, the real food (Garraedduk) was prepared by applying the optimal conditions. As a result, there was no significant difference between the predicted value (77.1) and the experiment value (76.6). This result showed that the in vitro digestibility in real food can be predicted by applying the gel model system.
        51.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study concerned the analysis on the efficiency of the conversion of water tank type supply system to direct water supply system to examine the feasibility of the conversion, as well as the calculation of optimal conversion range that enables the supply of safe, high-quality water at stable pressure in accordance with the standards of water supply facility. The results of this research showed that when converting water supply system from water tank type supply system to direct water supply system, more nodal points could be properly converted and more reduction of electricity usage was expected in case water pressure rather than residence time was fixed. This means that higher efficacy can be obtained by fixing water pressure when converting water supply system. However, since the number of the locations that received on-spot inspection was small and the electricity usage measured was not exclusively by water supply facility, it is difficult to judge that such reduction of electricity usage accurately represents reduced electricity usage by water supply facility alone. therefore, after having secured on-spot information about a larger number of locations in apartment complexes that have converted water supply system, and utilizing information about electricity usage exclusively by water supply facility, the proposed method of this research could be applied to accurately deducing expected reduction of electricity usage by water supply facilities of various other apartment complexes. It is also considered possible to deduce an effective operation method of water supply system by finding out an area that shows low pressure or low residual chlorine concentration in the optimal conversion range of water supply, followed by estimating the proper location of pumping station or the proper chlorine dosage at the power purification plant that supply water to the target area.
        4,000원
        52.
        2017.04 구독 인증기관·개인회원 무료
        Many insects possess symbiotic microorganisms in their bodies, wherein host-symbiont intimate interactions occur. Despite recent advances in omics technology, the molecular bases of the symbiotic associations remain unclear. The bean bug Riptortus pedestris harbors an environmentally acquired Burkholderia symbiont in their midgut crypts. Unlike other insect symbionts, the Burkholderia symbiont is easily culturable and genetically manipulatable outside the host insect. In conjunction with the experimental advantages of the bean bug, the Riptortus–Burkholderia association is an ideal model system for approaching the molecular bases underpinning insect-microbe symbioses. In this presentation, the current knowledge of this model system is summarized.
        53.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development of an appropriate public service quality model has become increasingly recognised as an important subject of interest in the public sector as well as academia. In particular, the public systems enacted by governments are widely used and have a significant impact on national competitiveness. But few researches have been conducted to explore the quality dimensions of a public system service and empirically examine the relationship among related variables. Therefore, in this study, we strive to develop a quality measurement model of public system service that can be effectively used in practice. Using 601 samples gathered through a structured survey from project engineers, a conceptual quality model of public system is presented and discussed. Given the exploratory nature of this study, an exploratory factor analysis is used to investigate quality dimensions and partial least square (PLS) is employed in determining the structural relationships. From empirical results, we found that the quality dimensions of the public system had four distinct quality dimensions (design quality, environment quality, primary outcome quality, additive outcome quality). All four quality dimensions showed good representative factors in explaining user satisfaction. Perceived trust was proved to significantly mediate the relationship between quality dimensions and user satisfaction. Our research is expected to contribute to the literature by providing a good conceptual framework for assessing public system quality by linking four quality dimensions with user satisfaction. In particular, the developed model can elaborately measure process quality and multi-functional outcome quality of the system by the supplementation of design quality and additive outcome quality respectively. Practical implications are also suggested on the basis of our analysis.
        4,800원
        54.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        UPS system in the liquefied natural gas(LNG) receiving terminal is one of the fundamental equipment that need to sustain operation during earthquake. In this study, modal identification test of UPS system was performed based on IEEE Std. 693-2005 and natural frequencies and modal damping, mode shapes had been identified. In addition, tri-axial time history test was performed to check the behavior and stress of the equipment during earthquake. Eigenvalue analysis was performed and analysis model was modified by reflecting the results of the test. Static analysis by dead weight and response spectrum analysis were performed to compare the combined stresses with the stress results of test. Dynamic characteristics and combined stresses under seismic load condition of the improved analysis model were similar to the test results and in this regard the compatibility was proved.
        4,000원
        55.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper a concept of the paradigm shift in the operations of Water and Wastewater systems regarding the production and usage of water was introduced. Based on this concept the interrelationships between the water quality in the upper basin of NakDong River relative to Busan and the degree of satisfaction of the customers on the water supply service in Busan were modeled using the System Dynamics modeling methodology. SamRangJin basin area was determined as the upper basin of Busan after analyzing the relationships between the water quality of MoolGeum water intake point and water quality data of various mid- and upper water intake points along NakDong River. The amount of contaminants generated in SamRangJin basin was modeled using the Gross Regional Domestic Product in the area and the treated amount was calculated using the efficiency of wastewater treatment and the degree of improvement of environmental condition per investment. The water quality at MoolGeum water intake point was modeled to take the effects of the remaining amount of contaminants after treatment and the non-point source contaminants in SamRangJin basin. Using the developed System Dynamics model the effects of the investment for the improvement of environmental condition in SamRangJin basin were compared to the case of alternate water source development for Busan in terms of the degree of satisfaction of the customers on the water supply service in Busan.
        4,000원
        56.
        2016.10 구독 인증기관·개인회원 무료
        Biogenic amines (BAs) are toxic nitrogenous compounds and formed by the microbial decarboxylation of amino acids during fermentation. Consumption of fermented foods high in BAs can pose the adverse health effects. The objective of current study was to develop a reduction method of BAs in fermented soybean paste by applying catechins during fermented koji manufacturing step. Analysis of BAs in fermented soybean paste was conducted using High Performance Liquid Chromatography (HPLC). The levels of Putrescine decreased for 63.7%, 60.1%, 76.1%, 73.4% for 0.3% addition of Epicatechin, Epicatechin gallate, Epigallocatechin, Epigallocatechin gallate, respectively. The levels of Cadaverine decreased for 24.3%, 34.3%, 42.6%, 37.2% for 0.3% addition of Epicatechin, Epicatechin gallate, Epigallocatechin, Epigallocatechin gallate, respectively. Especially, The best reduction effect of BAs appeared for 0.3% addition of Epigallocatechin. Current study demonstrated the potential use of catechins for reduction of biogenic amines in fermented soybean paste model. Finding from this research can practically guide fermented food industry by providing practical application of additives for reduction of BAs.
        57.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper suggests a specific model that could efficiently improve the interaction and the interface between MES(Manufacturing Execution System) server and PDA terminal through RFID(Radio Frequency Identification) system and bar-code system in automative transmission shipment place of the finished assembly parts. The proposed model shows that the new method by RF-Tag system can more efficiently perform to reduce processing time and loading time for shipment, compared with the current approach by bar-code system. It is noted in case of the method by RF-Tag that the effects of proposed model are as follows; (a) While the shipping lead time per truck for carrying by the current method was 35 minutes, the shipping lead time by the new method was 15 minutes. (b) While the accuracy for carrying by the current method was 50%, the accuracy by the new method was 99%.
        4,000원
        58.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The recent development of modern weapon system by SOS (System of System) has required users to have more exact decision making. It is possible to achieve the control of complex weapon system more efficiently and effectively by increasing usability. Accordingly, many studies on graphical display have been conducted for several years in the field of HCI (Human Computer Interaction) and GUI (Graphic User Interface), starting from its design stage. Therefore, this paper focuses on evaluating the system GUI usability and analyzing several important points based on performance model, which is a tool for the evaluation and the improvement of service quality. Performance Model, the main focus of this study, reflects user expectations (which is defined as user importance in this paper). The study consists of four steps. First, 34 checklists are drawn from the existing studies related to GUI usability evaluation by using a heuristic method, and then the checklists are matched with 11 weapon system design factors. Next, the study evaluates the importance of GUI element and the usability of weapon system “A” with the checklists twice respectively. Third, the performance of user importance (Pi) and the performance of usability (Pu) are calculated by modifying a numerical formula for normalization in this step. Finally, the study compares the approach it takes and the existing usability evaluation method, demonstrating that there is a significant difference between the two methods as a result. In addition, 4 improvement factors are suggested for weapon system “A” as “Shortcut” and “Description of Abbreviation,” and so on. Although it is necessary to conduct more studies for higher reliability and validity of the results, this study is meaningful considering it takes a new point of view.
        4,000원
        59.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As technology has developed and cost for data processing has reduced, big data market has grown bigger. Developed countries such as the United States have constantly invested in big data industry and achieved some remarkable results like improving advertisement effects and getting patents for customer service. Every company aims to achieve long-term survival and profit maximization, but it needs to establish a good strategy, considering current industrial conditions so that it can accomplish its goal in big data industry. However, since domestic big data industry is at its initial stage, local companies lack systematic method to establish competitive strategy. Therefore, this research aims to help local companies diagnose their big data capabilities through a reference model and big data capability assessment system. Big data reference model consists of five maturity levels such as Ad hoc, Repeatable, Defined, Managed and Optimizing and five key dimensions such as Organization, Resources, Infrastructure, People, and Analytics. Big data assessment system is planned based on the reference model’s key factors. In the Organization area, there are 4 key diagnosis factors, big data leadership, big data strategy, analytical culture and data governance. In Resource area, there are 3 factors, data management, data integrity and data security/privacy. In Infrastructure area, there are 2 factors, big data platform and data management technology. In People area, there are 3 factors, training, big data skills and business-IT alignment. In Analytics area, there are 2 factors, data analysis and data visualization. These reference model and assessment system would be a useful guideline for local companies.
        4,000원
        60.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Companies build the factory automation system to improve management effectiveness and productivity as prime strategies for sustainable growth. But most companies undergo various trials and errors while carrying out the project without elaborate preparation stage for factory automation. In this study, we tried to verify what factors are critical to effectively building distribution automation system, which is a branch of factory automation system. A consulting model for setting up a Material Handling Automation System by utilizing the Stage-Gate Process, which is product development process was studied. 29 material handling automation projects carried out between the year 1990 to 2013 at K-Company were selected. Interviews with the project managers, operators and maintenance personnels, various records and current status of the projects were used as data for structural equations based on the Milan consulting model and existing researches of factory automation, CIM for material handling automation. Creating effective basis of production, material handling system and energy saving system with expert review, when preparing a material handling automation project, help promote the project planning thus contributing to the performance of the resulting system, which appears though rather weakly in our data. Also the effect of material handling automation can be enhanced through sufficient and effective links to the relevant environments such as production logistics management and automated warehouses. More detailed planning characteristics of project promotion or some time-series data of effective Material Handling Automation System could enhace furthur studies. We propose a consulting model for setting up an efficient material handling automation system.
        4,000원
        1 2 3 4 5