• Journal of KIISE:Databases
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• v.33 no.1
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• pp.1-11
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• 2006

It is possible to track the moving vehicle as well as to develop the location based services actively according to the progress of wireless telecommunication and GPS, to the spread of network, and to the miniaturization of cellular phone. To provide these location based services, it is necessary for an index technique to store and search too much moving object data rapidly. However the existing indices require a lot of costs to insert the data because they store every position data into the index directly. To solve this problem in this paper, we propose a buffer node operation and design a GU-tree(Group Update tree). The proposed buffer node method reduces the input cost effectively since the operation stores the moving object location data in a group, the buffer node as the unit of a non-leaf node. hnd then we confirm the effect of the buffer node operation which reduces the insert cost and increase the search performance in a time slice query from the experiment to compare the operation with some existing indices. The proposed tufter node operation would be useful in the environment to update locations frequently such as a transportation vehicle management and a tour-guide system.

• Journal of Korea Water Resources Association
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• v.49 no.5
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• pp.361-372
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• 2016

Reliable long-term dam inflow prediction is necessary for efficient multi-purpose dam operation in changing climate. Since 2000s the teleconnection between global climate indices (e.g., ENSO) and local hydroclimate regimes have been widely recognized throughout the world. To date many hydrologists focus on predicting future hydrologic conditions using lag teleconnection between streamflow and climate indices. This study investigated the utility of teleconneciton for predicting dam inflow with 1-month lead time at Andong dam basin. To this end 40 global climate indices from NOAA were employed to identify potential predictors of dam inflow, areal averaged precipitation, temperature of Andong dam basin. This study compared three different approaches; 1) dam inflow prediction using SWAT model based on teleconneciton-based precipitation and temperature forecast (SWAT-Forecasted), 2) dam inflow prediction using teleconneciton between dam inflow and climate indices (CIR-Forecasted), and 3) dam inflow prediction based on the rank of current observation in the historical dam inflow (Rank-Observed). Our results demonstrated that CIR-Forecasted showed better predictability than the other approaches, except in December. This is because uncertainties attributed to temporal downscaling from monthly to daily for precipitation and temperature forecasts and hydrologic modeling using SWAT can be ignored from dam inflow forecast through CIR-Forecasted approach. This study indicates that 1-month lead dam inflow forecast based on teleconneciton could provide useful information on Andong dam operation.

• Journal of Korea Water Resources Association
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• v.50 no.7
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• pp.441-453
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• 2017

Water distribution networks (WDNs) supply drinking water to end users by maintaining sufficient water pressure for reliable water supply in normal and abnormal conditions. To design and operate WDNs in efficient way, it is required to quantify water supply ability of the network. Various reliability indices have been developed and applied in this field. Most of the reliability indices are calculated based on the energy within a network; that is, the total energy entered the network, the energy dissipated through water supply process, and the energy finally supplied at the nodes, etc. This study explains the energy composition in WDNs and introduces three well-known reliability indices developed based on the energy composition of the network. The three indices were applied to a study network under various demand loading scenarios that could occur in real-life operation practices. This study aimed to investigate the applicability of the reliability indices under abnormal scenarios and proposed to illustrate the spatial distribution of the system reliability in more intuitive way for proper responses to the abnormal situations.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.143-146
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• 2004

This paper presents a method to improve reliability by dispersed generation (DG) installation considering load types and interruption cost. The objective functions such as power losses cost, operation cost of DGS, power buy cost and interruption cost are minimized for reliability improvement and efficient operation. The several indices for reliability evaluation are improved by dispersed generation system installation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.47-59
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• 1994

The irrigation reservoir operation models developed were tested with weather and field data, and the sensitivity of the water requirement deficiency indices(WRDI) were checked with different initial reservoir storages, irrigated areas, and other water uses from the reservoir storage. Seven reservoir release rules were applied to Yongseol Reservoir. Twenty year WRDIs were computed to check performances of those reservoir release rules. Mean WRDIs were 138, 198, 198, 200, 240, 344, and 1033mm for ROM, TOS, COS, CRR, MSC, FAS, and SRC, respectively. The results indicated that ROM contributes consistently to higher operation efficiencies of an irrigation reservoir. The test results of LFROM and SFROM showed that reservoir operation with the proposed optimization technique ROM would be better suited for an irrigation district than those with the other rules. And the proposed model could be used as a tool to improve reservoir operations.

• Biomedical Science Letters
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• v.16 no.4
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• pp.247-258
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• 2010

The objective of this research was to evaluate the relationships of preoperative (Pre-OP) levels of hematological and biochemical indices to perioperative variables in patients that underwent coronary artery bypass graft surgery (CABG). Pre-OP levels of hematological factors [total white blood cells (T-WBC), erythrocytes, hemoglobin, hematocrit, glycohemoglobin A1c (HbA1c), or platelet] were negatively or positively related with biochemical indices [alanine aminotransferase (ALT), bilirubin, glucose, fructosamine, triglyceride, and high density lipoprotein cholesterol (HDL)]. Pre-OP levels of hematological factors and biochemical indices were negatively or positively correlated with echocardiographic variables. Pre-OP level of HbA1c had a relationship with C-reactive protein. Pre-OP levels of aspartate aminotransferase (AST), ALT, HDL, glucose, fructosamine, or blood urea nitrogen (BUN) were positively or negatively associated with Pre-OP levels of cardiac markers (brain natriuretic peptide, troponin-I, creatine kinase isoenzyme 2, or CRP). Pre-OP levels of hematological factors (excepting T-WBC) related with operation time (OPT), postoperative mechanical ventilation time (POMVT), intensive care unit-period (ICU-period) or hospitalization. Pre-OP levels of AST, ALT, bilirubin, triglyceride, HDL, low dwensity lipoprotein, fructosamine, or BUN were positively or negatively correlated with OPT, graft numbers, POMVT, ICU-period or hospitalization. Retrospective this study reveals that Pre-OP levels of hematological and biochemical markers are associated with echocardiographic variables, several cardiac markers and postoperative outcomes, suggesting that Pre-OP levels of hematological and biochemical markers may be useful predictors for the diagnosis and prognosis of coronary artery disease.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.8
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• pp.731-740
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• 1991

This paper presents a knowledge based system to solve reactive power/voltage control problem in a power system. The methods to reduce inference time are proposed in inferring the solution of problem in the knowledge base which consists of heuristic rules and inowledge of experts. A set of indices drawn from the heuristic knowledge on the power system is utilized to make up for the defect of existing knowledge based systems which determine both the location and the amount of reactive power compensation devices. The concept of set of indices developed in this paper makes it possible to infer the amount of reactive power source only since the bus order list representing priority for the location of reactive power compensator to be switched on can be determined in advance. From the fact that there exists a relationship between the system voltage pattern and the reactive power pattern in operation, the pattern recognition technique is introduced to reduce the inference time in solving the severe voltage problem. To demonstrate the usefulness of the proposed knowledge based system, the IEEE 30 bus system is chosen as a sample system. The results of case study are also presented.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1416-1421
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• 1992

There are many objective indices of operative outcome of funnel chest, but there has been only a few report about the postoperative change of these indices and which is best correlated with subjective outcome. From January 1989 to December 1991, 74 patients with funnel chest underwent Ravitch operation and radiologic evaluation was performed on the twenty patients whose operative outcome were satisfactory by Humphreys` criteria and postoperative chest X-ray were available. Variable radiologic chest idices such as deformity grade [DG], lower vertebral index [LVI], upper vertebral index [UVI] and configuration index [CI] were measured preoperatively and 1, 6, 12 and 18 months pos-toperatively. The mean value of preoperative DG, LVI, UVI and CI were 5.32, 0.3, 0.26 and 1.01 respectively, and postoperative chages were as follows; DG; 3.13, 3.66, 3, 72, 4.0, LVI: 0.22, 0, 24, 0.25, 0.25 UVI; 0.27, 0.27, 0.27, 0.27 CI; 0.69, 0.77, 0.76, 0.79. The increments of CI were within the 90 percent confidence limit of normogram in most cases, but it was not true for LVI and UVI. And the differences between the observed and expected values of CI did not change significantly through the postoperative periods, which was not the case in LVI. We concluded from these results that 1] DG, LVI and CI were increased slowly during the postoperative follow up periods but the increments of CI were usually within the normal limits and so 2] CI can be used as a objective index of satisfactory outcome.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.339-346
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• 2017

The Korea Adaptation Center for Climate Change (KACCC) located in Korea Environment Institute has serviced a climate change vulnerability assessment support tool (VESTAP) since 2014 in order to help local governments to establish their own adaptation plans. Owing to its easy usage, the VESTAP has been utilized by not only local governments but also academia for examination of climate change vulnerability in various fields. However, the KACCC has not suggested a standard usage how to compose indices for climate exposure, sensitivity, and adaptation capacity which are main components of vulnerability although the KACCC manages operation and application of the VESTAP. Many users had no choice but to compose indices based on their own interpretation on the components of vulnerability. This technical note suggests the standard usage of VESTAP by reevaluating some vulnerability assessments previously developed. This may help users to correctly compose indices for climate change vulnerability assessment, and may minimize possibility of inter-user inconsistency in definition of vulnerability assessments.

• Smart Structures and Systems
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• v.16 no.4
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• pp.743-758
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• 2015

This paper presents an advanced life cycle cost (LCC) analysis of a ground source heat pump (GSHP) system and suggests a smart operation mode with a thermal performance test (TPT) and an energy pile system constructed on the site of the Incheon International Airport (IIA). First, an economic analysis of the GSHP system was conducted for the second passenger terminal of the IIA considering actual influencing factors such as government support and the residual value of the equipment. The analysis results showed that the economic efficiency of the GSHP system could be increased owing to several influential factors. Second, a multiple regression analysis was conducted using different independent variables in order to analyze the influence indices with regard to the LCC results. Every independent index, in this case the initial construction cost, lifespan of the equipment, discount rate and the amount of price inflation can affect the LCC results. Third, a GSHP system using an energy pile was installed on the site of the construction laboratory institute of the IIA. TPTs of W-shape and spiral-coil-type GHEs were conducted in continuous and intermittent operation modes, respectively, prior to system operation of the energy pile. A cooling GSHP system in the energy pile was operated in both the continuous and intermittent modes, and the LCC was calculated. Furthermore, the smart operation mode and LCC were analyzed considering the application of a thermal storage tank.