• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.113-122
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• 2015

This study aims to evaluate future stream flow by the operation of agricultural reservoir group at the upper stream of the Miho River. Four agricultural reservoirs with storage capacities greater than one million cubic meters within the watershed were selected, and the RCP 8.5 climate change scenario was applied to simulate reservoir water storage and stream flow assuming that there are no changes in greenhouse gas reduction. Reservoir operation scenarios were classified into four types depending on the supply of instream flow, and the water supply reliability of each reservoir in terms of water supply under different reservoir operation scenarios was analyzed. In addition, flow duration at the watershed outlet was evaluated. The results showed that the overall run-off ratio of the upper stream watershed of the Miho River will decrease in the future. The future water supply reliability of the reservoirs decreased even when they did not supply instream flow during their operation. It would also be difficult to supply instream flow during non-irrigation periods or throughout the year (January-December); however, operating the reservoir based on the operating rule curve should improve the water supply reliability. In particular, when instream flow was not supplied, high flow increased, and when it was supplied, abundant flow, ordinary flow, and low flow increased. Drought flow increased when instream flow was supplied throughout the year. Therefore, the operation of the agricultural reservoirs in accordance with the operating rule curve is expected to increase stream flow by controlling the water supply to cope with climate change.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.99-99
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• 2009

Two different micro-flows during the evaporation of ink droplets were achieved by engineering both surface tension gradient and compositional gradient across the ink droplet: (1) Coffee-ring generating flow resulting from the outward flow inside the ink droplet & (2) Marangoni flow leading to the circulation flow inside the ink droplet. The surface tension gradient and the compositional gradient in the ink droplets were tailored by mixing two different solvents with difference surface tension and boiling point. In order to create the coffee-ring generating flow (outward flow), a single-solvent system using N,N-dimethylformamide with nano-sized spherical alumina particles was formulated, Marangoni flow (circulation flow) was created in the ink droplets by combining N,N-dimethylformamide and fotmamide with the spherical alumina powders as a co-solvent ink system. We have investigated the effect of these two different flows on the formation of ceramic films by inkjet printing method, The packing density of the ceramic films printed with two different ink systems (single- and co-solvent systems) and their surface roughness were characterized. The dielectric properties of these inkjet-printed ceramic films such as dielectric constant and dissipation factor were also studied in order to evaluate the feasibility of their application to the electronic ceramic package substrate.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.109-111
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• 2015

The Arctic transportation offers big opportunities as shorter transport distances, less fuel consumption, less carbon emissions, faster deliveries of goods, and more profits. The present study is aimed to investigate a future flow to deal with policy in arctic transportation using Big data analysis.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.9
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• pp.1409-1418
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• 2009

This study investigates the relationship among interactivity, telepresence, flow, and future behavior intention in internet shopping. Respondents were female consumers age 20 to 30. These consumers are regarded to have experience in internet shopping. 500 samples were used in this research. For data analysis, descriptive statistics, factor analysis, ANOVA, and multiple regression analysis were used for this study. As the result, interactivity, telepresence, and flow affect future behavior intention. Flow is the most influential variable affecting the future behavior intention. It implies that hedonic shopping experience (aroused by flow) can increase the future behavior intention of consumers. Consumers can operate and change the product image with convenience by encouraging interactivity between the internet fashion shopping mall and consumers. Through the technology, the experience 'flow' of consumers can provide a sense of telepresence as if they were shopping in a real store. Consumers may feel unconscious of the passage of time and feel fun, free, and original. Therefore, the internet shopping mall should pay attention to what customers demand and reflect it through e-mail, real time chatting, and text messages. In addition, rich product information such as detailed images should be supplied to help customers visualize looks.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.34-45
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• 2013

Recently, world-wide research activities on new network architectures and protocols are being actively progressed. Furthermore, research activities on testbed and related technologies for supporting those activities are being actively performed. In domestic study, research on the OpenFlow protocol based future Internet testbed implementation and research on its virtualization for supporting independent research experiments are being performed at the same time. The network virtualization is a technology which maximizes the testbed utilization without interfering each other for the individual research when many researchers share the testbed. In this paper, we implemented a Enhanced FlowVisor by extending basic FlowVisor by adding QoS functions which are admission control and minimum bandwidth guarantee. On the testbed, we performed a real-time video streaming experiment for verifying the performance of the Enhnaced FlowVisor on the OpenFlow protocol based future internet testbed. The result shows that the Enhanced FlowVisor can provide reliable and stable QoS to the individual researches without disturbing each other traffic on virtualized networks of the future Internet testbed.

• Korea Journal of Hospital Management
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• v.11 no.3
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• pp.19-41
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• 2006

The Objective of this study was to design the model which predict the future cash flow of hospitals and on the basis of designed model to support sound hospital management by the prediction of future cash flow. The five cash flow measurement variables discussed in financial accrual part were used as variables and these variables were defined as NI, NIDPR, CFO, CFAI, CC. To measure the cash flow B/S related variables, P/L related variables and financial ratio related variables were utilized in this study. To measure cash flow models were designed and to estimate the prediction ability of five cash flow models, the martingale model and the market model were utilized. To estimate relative prediction outcome of cash flow prediction model and simple market model, MAE and MER were used to compare and analyze relative prediction ability of the cash flow model and the market model and to prove superiority of the model of the cash flow prediction model, 32 Regional Public Hospital's cross-section data and 4 year time series data were combined and pooled cross-sectional time series regression model was used for GLS-analysis. To analyze this data, Firstly, each cash flow prediction model, martingale model and market model were made and MAE and MER were estimated. Secondly difference-test was conducted to find the difference between MAE and MER of cash flow prediction model. Thirdly after ranking by size the prediction of cash flow model, martingale model and market model, Friedman-test was evaluated to find prediction ability. The results of this study were as follows: when t-test was conducted to find prediction ability among each model, the error of prediction of cash flow model was smaller than that of martingale and market model, and the difference of prediction error cash flow was significant, so cash flow model was analyzed as excellent compare with other models. This research results can be considered conductive in that present the suitable prediction model of future cash flow to the hospital. This research can provide valuable information in policy-making of hospital's policy decision. This research provide effects as follows; (1) the research is useful to estimate the benefit of hospital, solvency and capital supply ability for substitution of fixed equipment. (2) the research is useful to estimate hospital's liqudity, solvency and financial ability. (3) the research is useful to estimate evaluation ability in hospital management. Furthermore, the research should be continued by sampling all hospitals and constructed advanced cash flow model in dimension, established type and continued by studying unified model which is related each cash flow model.

• Journal of KIISE:Information Networking
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• v.41 no.4
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• pp.167-176
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• 2014

In this paper, we discuss the implementation and experimentations of a new future Internet architecture for mobile-oriented environments, named Mobile Oriented Future Internet (MOFI). The MOFI architecture is featured by the host identifier and local locator for identifier-locator separation, Query-First Data Delivery (QFDD), and Distributed Mapping System (DMS) for identifier-locator mapping control. In the existing study on MOFI, we examined the intra-domain mobility control, the implementation of MOFI over Linux platform, and the performance analysis over the small-scale testbed. In this paper, we describe how to implement the MOFI architecture for inter-domain mobility control by using the OpenFlow and Click Modular Router platform. From the experimentations over the KOREN testbed, we can see that the MOFI scheme can give better performance than the existing Proxy Mobile IP scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.118-127
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• 2010

Current TCP/IP-based Internet architecture has been used for over 30 years, however it will confront with fundamental problems due to new protocol extension limitation since communication environments will change drastically and various user requirements will be emerging in near future. To solve these problems, major countries have started Future Internet researches based on clean slate approach and they will deploy large-scale testbed to experiment and verify new functions. OpenFlow switch technology has been proposed as a new experimental technology for independent protocol that can utilized the legacy network devices and does not interfere with the production Internet traffic. Korea also started Future Internet testbed project called FIRST and OpenFlow switch with NetFPGA card will be used to deploy this testbed. To interconnect distributed testbed using OpenFlow switches, logical tunnel should be established by encapsulating MAC frame inside a unicast IP packet between OpenFlow switches because OpenFlow switches are not directly connected. In this paper, we have implemented a NetFPGA-based that performs MAC in IP tunneling between various OpenFlow switch sites implemented in domestic research network KOREN. The performance evaluation shows that the NetFPGA-based capsulator reveals better performance than the software-based tunneling and it can be utilized as a testbed for experimentation of Future Internet technologies.

• The Journal of Fisheries Business Administration
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• v.40 no.1
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• pp.51-74
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• 2009

The purpose of this study is to ascertain that how the futures market of the Japanese frozen shrimp that is the only fisheries asset all over the world can be efficient. Accordingly, this paper examines efficiency and information flow of the Japanese frozen shrimp market using data from Kansai Commodities Exchange frozen shrimp futures closing prices and spot prices. And then this paper estimates a forward price model using that data. From the model, risk premium is estimated and we could also analyse the future information flow into the futures market which reveals future spot prices. This thesis reached to conclusions as follows: First, the null of zero risk premium is rejected and the value of that is negative. Second, the time pattern of information flow into the futures market is that most of the information on future price arrives within a week and for the last week, most of relevant information is already incorporated. The result of this study contrasts with that of Stockman(1978) about currency futures market of U.S.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.2-4
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• 2010

Due to rapid progress in the performance of high-end computers, numerical prediction of fluid flow and flow-induced sound is expected to become a vital tool for aero- and hydro- dynamic design of various flow-related products. This presentation focuses on the applications of large-scale numerical simulations to complex engineering problems with a particular emphasis placed on the low-speed flows. Flow field computations are based on a large eddy simulation that directly computes all active eddies in the flow and models only those eddies responsible for energy dissipations. The sound generated from low-speed turbulent flows are computed either by direct numerical simulation or by decoupled methods, according to whether or not the feedback effects of the generated sound onto the source flow field can be neglected. Several numerical examples are presented in order to elucidate the present status of such computational methods and discussion on the future prospects will also be given.