• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.2
• /
• pp.37-44
• /
• 2013

Generally, a reduced chemical mechanism of n-heptane is used as chemical fuel of a 3-D diesel engine simulation because diesel fuel consists of hundreds of chemical components and various chemical classes so that it is very complex and large to use for the calculation. However, the importance of fuel in a 3-D simulation increases because detailed fuel characteristics are the key factor in the recent engine research such as homogeneous charged compression ignition engine. In this study, normal paraffin, iso paraffin and aromatics were selected to represent diesel characteristics and n-dodecane was used as a representative normal paraffin to describe the heavy molecular weight of diesel oil (C10~C20). Reduced kinetics of iso-octane and toluene which are representative species of iso paraffin and aromatics respectively were developed in the previous study. Some species were selected based on the sensitivity analysis and a mechanism was developed based on the general oxidation scheme. The ignition delay times, maximum pressure and temperature of the new reduced n-dodecane chemical mechanisms were well matched to the detailed mechanism data.

• Health Policy and Management
• /
• v.32 no.1
• /
• pp.53-62
• /
• 2022

Background: This study was designed to examine regional proportions for people who experienced unmet health care needs due to reduced mobility or unhealthiness and factors associated with experience of unmet health care needs by them. Methods: A total of 11,620 people were retrieved from the Korea Health Panel data (2014-2018). Regional proportions for people who experienced unmet health care needs due to reduced mobility or unhealthiness were estimated using cross-sectional weights and the factors associated with them were analyzed using generalized estimating equation. Results: The number of people who experienced unmet health care needs due to reduced mobility or unhealthiness was estimated as 278,083 in 2018. Women, the aged (65+), below elementary school, single as marital status, low income, bad self-rated health, people with disabilities, and long-term insurance beneficiaries were statistically significantly associated with experience of unmet health care needs due to reduced mobility or unhealthiness. Conclusion: Given high and dispersed demand for visiting health care, government need to expand the infrastructure and finance to facilitate visiting health care.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1499-1502
• /
• 2008

This paper proposes an efficient data compression for the conventional method of reducing EMI in a 10 bit LCD timing controller (TCON). In addition, we develop a new method to reduce EMI in a LCD TCON through repeated data on adjacent blocks. The novel technique reduced EMI by 10 dB for a 52" FHD 10it LCD TV.

• Communications for Statistical Applications and Methods
• /
• v.16 no.5
• /
• pp.881-889
• /
• 2009

Support vector machines(SVMs) are known as flexible and efficient classifier of multivariate observations, producing a hyperplane or hyperdimensional curved surface in multidimensional feature space that best separates training samples by known groups. As various methodological extensions are made for SVM classifiers in recent years, it becomes more difficult to understand the constructed model intuitively. The aim of this paper is to visualize various SVM classifications tuned by several parameters in reduced dimensions, so that data analysts secure the tangible image of the products that the machine made.

• Journal of the Optical Society of Korea
• /
• v.15 no.2
• /
• pp.168-173
• /
• 2011

Based on the distinctive characteristics observed in the intensity transmittance of an IPS-LC panel, the previous one-dimensional model is greatly reduced such that only a few data points and their interpolations predict the intensity transmittance of an IPS-LCD with a small error for arbitrary gray levels. Experimental procedure and numerical methods are described in detail.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.7
• /
• pp.1307-1311
• /
• 2006

In this paper, we propose new speech feature parameter using the Matrix Factorization for appearance part-based features of speech spectrum. The proposed parameter represents effective dimensional reduced data from multi-dimensional feature data through matrix factorization procedure under all of the matrix elements are the non-negative constraint. Reduced feature data presents p art-based features of input data. We verify about usefulness of NMF(Non-Negative Matrix Factorization) algorithm for speech feature extraction applying feature parameter that is got using NMF in Mel-scaled filter bank output. According to recognition experiment results, we confirm that proposed feature parameter is superior to MFCC(Mel-Frequency Cepstral Coefficient) in recognition performance that is used generally.

• Asian-Australasian Journal of Animal Sciences
• /
• v.2 no.4
• /
• pp.607-613
• /
• 1989

The validity of the hypothesis that between-breed differences of carcass composition in cattle can be reduced when compared at the same degree of maturity was assessed using carcass data of various breeds obtained from slaughter experiments in Denmark, Japan and Malaysia. All cattle were kept in intensive feeding conditions in this study. With respect to temperate data (Danish and Japanese data), although large between-breed differences were found in carcass composition in the comparison at the same slaughter weight, the differences were reduced when compared at the same degree of maturity. This result supported the above hypothesis. Kedah-Kelantan and their crosses in Malaysian data, however, had more muscle and bone contents but less fat content than temperate breeds, even if compared at the same degree of maturity. This could be attributed to the history that native Kedah-Kelantan breed has adapted itself in the direction of decreasing fat deposition which requires much energy and prevents heat evaporation, in order to survive under high temperature and high humiodity conditions in Malaysia. In spite of the same tropical breed, carcass composition of Sahiwal-Friesian was similar to that of other temperate breeds at the same degree of maturity.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.178-181
• /
• 2005

The positioning accuracy of the Global Positioning System (GPS) has been improved considerably during the past two decades. The main error sources such as ionospheric refraction, orbital uncertainty, antenna phase center variation, signal multipath, and tropospheric delay have been reduced substantially, if not eliminated. In this study, the GPS data collected by the GPS receivers that were established as continuously operating reference stations by International GNSS Service (IGS), Ministry of the Interior (MOl), Central Weather Bureau (CWB), and Industrial Technology Research Institute (ITRI) Of Taiwan are utilized to investigate the impact of atmospheric water vapor on GPS positioning determination. The surface meteorological measurements that were concurrently acquired by instruments co-located with the GPS receivers include temperature, pressure and humidity data. To obtain the influence of the GPS height on the proposed impact study. A hydrodynamic ocean tide model (GOTOO.2 model) and solid earth tide were used to improve the GPS height. The surface meteorological data (pressure, temperature and humidity) were introduced to the data processing with 24 troposphere parameters. The results from the studies associated with different GPS height were compared for the cases with and without a priori knowledge of surface meteorological measurements. The finding based on the measurements in 2003 is that the surface meteorological measurements have an impact on the GPS height. The associated daily maximum of the differences is 1.07 cm for the KDNM station. The impact is reduced due to smoothing when the average of the GPS height for the whole year is considered.

• Ocean and Polar Research
• /
• v.28 no.4
• /
• pp.439-449
• /
• 2006

This study was aimed at measuring the fishing capacity of Powered Anchovy Drag Net Fisheries (PADNF) in Korea using Peak-to-Peak(PTP) and Data Envelopment Analysis(DEA) methods recommended by FAO. In the analysis, both fishing capacities of total PADNF and individual PADNF vessels were measured with time series data and cross sectional data, respectively. In addition, the results of the DEA measurement were analyzed in order to determine reduction levels of fishing capacity. In case of total PADNF, the results by rn and DEA methods showed a similar rate of capacity utilization (79%), indicating the capacity was not utilized enough. In addition, the sensitivity analysis suggested that the number of vessels should be reduced by 20%, and the gross tonnage and the horse power should be reduced by 20% and 21%, respectively if the current catch is to stay at the 2004 level. The DEA results on individual PADNF vessels indicated the capacity utilization was 75% on average, showing some differences in capacity utilization among vessels (31%-100%). The results of the study would be useful for measuring production efficiency in PADNF. They would also provide good policy information for efficient use of resources and capacity reduction levels, which are useful far vessel buyback programs of coastal and offshore fisheries.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.279-283
• /
• 2009

Distributed generation(DG) of combined cooling, heat. and power(CCHP)has been gaining momentum in recent year as efficient, secure alternative for meeting increasing energy demands. This paper presents the energy performance of microturbine CCHP system equipped with an absorption chiller by modelling it in hospital building. The orders of study were as following. 1)The list and schedule of energy consumption equipment in hospital were examined such as heating and cooling machine, light etc. 2) Annual report of energy usage and monitoring data were examined as heating, cooling, DHW, lighting, etc. 3) The weather data in 2007 was used for simulation and was arranged by meteorological office data in Daejeon. 4) Reference simulation model was built by comparison of real energy consumption and simulation result by TRNSYS and ESP-r. The energy consumption pattern of building were analyzed by simulation model and energy reduction rate were calculated over the cogeneration. As a result of this study, power generation efficiency of turbine was about 30% after installing micro gas turbine and lighting energy as well as total electricity consumption can be reduced by 40%. If electricity energy and waste heat in turbine are used, 56% of heating energy and 67% of cooling energy can be reduced respectively, and total system efficiency can be increased up to 70%.