• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.4_1
• /
• pp.129-136
• /
• 1992

A precedure for recovering surface displacement from a time series of pressure measured by a pressure gage in a shallow water (that is, FFTM, LCM. IWM) is investigated with respect to a proper cut-off-frequency of a frequency response function for the accurate recovery of wave height and period. The authors examined the applicability of above mentioned three transformation procedures through field observations and laboratory experiments and the following results are obtained. i) The cut-off-frequency of the frequency response function used in FFTM is deeply depend on both the frequency response of the pressure sensor and the water depth at the sensor. In this study, a relatively accurate surface displacement can be recovered when the frequency response function is cut off at the frequency corresponding to kh=3.0 where k is a wave number at the depth of h. The frequency response function in the region higher than the cut-off-frequency is set constant to be the value at the cut-off-frequency. ii) The transformed surface displacements by LCM are affected by the small waves of short periods included in the measured pressure. It is found that pressure variation whose local frequency is higher than kh=1.5 has to be neglected to recover surface displacement sufficiently. iii) In IWM, the linear pressure response function is usually utilized by multiplying a coefficient N which is a function of the frequency (or kh) and takes a value around unity. However, in this study, a constant value of N(=1.0) gives a relatively accurate recovery of surface displacements.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.3
• /
• pp.322-329
• /
• 2011

A whole genome association (WGA) study was conducted to identify quantitative trait loci (QTL) for body conformation traits in Hanwoo cattle. The phenotypes of 497 steers were recorded from the Hanwoo Improvement Center of National Agricultural Cooperative Federation, Seosan, Korea, and analyzed using the Illumina Bovine 50 k SNP chip. A set of 35,987 SNPs that were available in the Hanwoo population was selected from the chip. After adjustments for the effects of year-season of birth, region and sire, phenotypes were regressed on each SNP using a linear regression model. Three hundred nineteen SNPs were detected for the ten conformation traits (p<0.003). For the significant SNPs, stepwise regression procedures were applied to determine best sets of markers. A total of 72 SNPs were selected (p<0.001), for which the sets of 5, 9, 10, 9, 8, 11, 4, 6, 3 and 7 SNPs were determined for height at withers, rump height, body length, chest depth, chest width, rump length, hip width, thurl width, pinbone width and heart girth, respectively. About 7-26% of the total phenotypic variation was explained by the set of SNPs for each trait. QTL for the conformation traits were harbored on most bovine chromosomes (BTAs). Four SNPs with pleiotropic effects on height at withers and rump height were detected on BTAs 3, 4, 6 and 16. A SNP with pleiotropic effects on chest width and rump length was also detected on BTA10. Two QTL regions, i.e. between 87 and 97 Mb in BTA3 and between 41 and 44 Mb in BTA7, were found, in which SNPs were detected for the five and three conformation traits, respectively. The detected SNPs need to be validated in other Hanwoo populations for commercial application to the genetic improvement of conformation characteristics in Hanwoo via marker-assisted selection (MAS).

• Journal of Korea Multimedia Society
• /
• v.13 no.3
• /
• pp.438-456
• /
• 2010

Iris recognition uses a unique iris pattern of user to identify person. In order to enhance the performance of iris recognition, it is reported that the diameter of iris region should be greater than 200 pixels in the captured iris image. So, the previous iris system used zoom lens camera, which can increase the size and cost of system. To overcome these problems, we propose a new method of enhancing the accuracy of iris recognition on low-resolution iris images which are captured without a zoom lens. This research is novel in the following two ways compared to previous works. First, this research is the first one to analyze the performance degradation of iris recognition according to the decrease of the image resolution by excluding other factors such as image blurring and the occlusion of eyelid and eyelash. Second, in order to restore a high-resolution iris image from single low-resolution one, we propose a new method based on multiple multi-layered perceptrons (MLPs) which are trained according to the edge direction of iris patterns. From that, the accuracy of iris recognition with the restored images was much enhanced. Experimental results showed that when the iris images down-sampled by 6% compared to the original image were restored into the high resolution ones by using the proposed method, the EER of iris recognition was reduced as much as 0.133% (1.485% - 1.352%) in comparison with that by using bi-linear interpolation

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.511-514
• /
• 1997

The objective of this study is to propose a finite element based design of the dental implant replacing unction and shape of natural teeth. For this, geometric actors were varied to investigate stress distribution of the alveolar bone around dental implant. In this study, the results were obtained based on the theory of linear elastic, with geometrically axisymmetric assumption. Geometric actors determining implant shape are ranged as 0.2mm-0.6mm, 0.04mm-0.1mm, 0.46mm-0.84mm or height of thread, radius of curvature of thread, and pitch, respectively. The stresses in the alveolar bone caused by biting force playa major role in determining implant stability. Especially, the stress concentration in the cortical bone causes bone resorption and finally makes the implant unstable. Therefore, the stress distributions were investigated on the side of the alveolar bone focusing on the area of cortical bone. The maximum von Mises stress was found to increase up to 6% as the height of thread increases, while its value was to decrease to 19% when the radius of curvature increase within the assigned ranges. For the variation of pitch, the larger size of pitch results in greater maximum von Mises stress when the length of the implant under consideration is fixed. The existence of the neck below the shoulder did not affect the stress distribution in the region of alveolar bone. However, the stresses on the side of the implant near the neck were found to be different by 20% approximately. Therefore, the neck can provide the stability of the implant against continuing biting movement. As a conclusion, the finite element based study shows a potential in designing the dental implant systematically.

• Applied Microscopy
• /
• v.24 no.2
• /
• pp.48-62
• /
• 1994

The acute irradiation effect on rat Purkinje cell was carried out. Anesthetized rats, weighing 200-250g each, were exposed their heads to the linear accelerator (ML-4MV) with the doses of 3,000 rads or 6,000 rads respectively. Irradiated rats were sacrificed by perfusion fixation under anesthesia, six hours, two days and six days following the irradiations. Rats were perfused with the fixative of 1% glutaraldehyde-1% paraformaldehyde solution (pH 7.4). Small pieces of cerebellar cortices were taken out. Tissue blocks were washed out, and were refixed in the 2% osmium tetroxide solution. After dehydration, tissues were embedded in the araldite mixture. Ultrathin sections stained with uranyl acetate-lead citrate solution, were examined with an electron microscope. The results observed were as follow; 1. Many dark Purkinje cells exhibited most severe cellular alterations on 6 hours. But after the 2 or 6 days, the cells exhibited only some alterations of cytoplasmic organelles. 2. Many granular and agranular endoplasmic reticula exhibited the fusion of cisterns. These reticular alterations were most severe on 6 hours following irradiation. But the alterations were hardly found on 6 days. 3. In the Golgi region, alterations including the adhesion of lamelliform cisterns, enlarged saccules, and increased number of vesicles, etc, were seen on 6 hours. But the Golgi complexes were almost recovered on 6 days. 4. Lysosomes were abundant on 6 hours or 2 days, but some residual bodies were found on 6 days. 5. Mitochondrial changes were also most severe at on hours, and they were recovered thereafter. From the results, it was concluded that the cerebellar Purkinje cells reacted to the high doses of irradiation by hyperactive protein synthesis, autolytic activities and energy metabolism. The reaction was most active in the early stage. It implies that motor-control function of Purkinje cells are severely disturbed in the early stage of irradiation.

• Korean Journal of Remote Sensing
• /
• v.35 no.6_4
• /
• pp.1373-1389
• /
• 2019

KOMPSAT-5 is the first satellite in Korea equipped with X-band Synthetic Aperture Radar (SAR) instrument and has been operated since August 2013. KOMPSAT-5 is used to monitor the global environment according to its observation purpose and the availability of KOMPSAT-5 is also highlighted as the need of high resolution wind data for investigating the coastal region. However, the previous study for the validation of wind derived from KOMPSAT-5 showed that the accuracy is lower than that of other SAR satellites. Therefore, in this study, we developed the correction equation of normalized radar cross section (NRCS or backscattering coefficient) for improvement of wind from the KOMPSAT-5 and validated the effect of the equation using the in-situ measurement of ocean buoys. Theoretical estimated NRCS and observed NRCS from KOMPSAT-5 showed linear relationship with incidence angle. Before applying the correction equation, the accuracy of the estimated wind speed showed the relatively high root-mean-square errors (RMSE) of 2.89 m s^-1 and bias of -0.55 m s^-1. Such high errors were significantly reduced to the RMSE of 1.60 m s^-1 and bias of -0.38 m s^-1 after applying the correction equation. The improvement effect of the correction equation showed dependency relying on the range of incidence angle.

• Journal of Korean Society of Transportation
• /
• v.24 no.4 s.90
• /
• pp.7-17
• /
• 2006

The purpose or this paper is to investigate the relationship between highway improvement and Induced Travel Demand(ITD) focusing on the Seoul metropolitan area data. In addition, authors tried to estimate basic unit of demand elasticity focusing on zone and trip purpose which can be applied for the ITD forecasting. The results are based on the 2002 Metropolitan Household Transportation Survey Data, where the demand elasticity (DE) is -0.582 in Seoul, -0.597 in Incheon and -0.559 in Gyounggi province, respectively. This study revealed part of the relationship between highway improvement and ITD for metropolitan region and provided the framework for yielding real estimated values by applying the concept of demand elasticity in terms of the relationship by using regional and long-term data. We expect that the basic unit of demand elasticity focusing on zone and trip purpose can be applied for the ITD forecasting to analyze the whole demand exactly The estimated DE's for age group and day of week can also be used for Proper transportation management and transport Policy making. Some limitations have also been discussed.

• Journal of Korean Society of Transportation
• /
• v.27 no.4
• /
• pp.195-206
• /
• 2009

The deregulation of aviation markets in Europe and the United Sates had led airlines to reconfigure their networks into hub-and-spoke systems. Recent trends of "Open Skies" in the Asian aviation market are also expected to prompt the reformation of airlines' networks in the region. A significant connectivity index is a crucial tool for airlines and airport authorities to estimate the degree of hub-and-spoke operations. Therefore, this paper suggests a new index, Continuous Indirect Connectivity Index (CICI), for measuring the coordination of airlines' flight schedules, applying it to the Asian, European and the American aviation markets. CICI consists of three components：(i) temporal connectivity to identify the attractiveness between connection flights, (ii) spatial connectivity to differentiate the attractiveness by de-routing distance with continuous linear function, and (iii) relative intensity to reflect the effect of direct flight frequency on transfer routes. CICI is evaluated to examine a casual relationship through regression analyses with two dependent variables of the number of transfer passengers and transfer rates. Compared with Danesi's index and Doganis' index through evaluation processes, CICI has a higher coefficient value of determination, implying that it explains the relationship between connectivity and transfer passengers more precisely.

• Journal of Korean Society of Transportation
• /
• v.35 no.1
• /
• pp.1-10
• /
• 2017

The compact city usually provides good accessibility of residents with multiple transportation modes. However, in a compact city, annual average of travel distance per household by car is relatively short due to more congested traffic condition and larger travel cost than disperse city. As a result, total travel demand is decreasing when the region becomes more compact. Therefore compact development is regarded as one of the sustainable choices for future urban planning in many countries. This study aims at an empirical analysis of the relationship between urban compactness and travel demand based upon land-use and travel data for city of Seoul. In this study, 424 sub-districts with the mixed land-use patterns are assessed in a hexagonal diagram. The measurement is based on the relative deviation of each sector's characteristics including numbers of residence, manufacture, and trade & service. Multiple linear regression models are developed to analyze the effects of urban compactness on zonal trip generations. As a result, the trip generation rate in the residence-intensive and mixed-use areas is found to be relatively low. Furthermore, residents in high-compact areas tend to use public transport more often than residents in less compact areas.

• The Korean Journal of Food And Nutrition
• /
• v.29 no.5
• /
• pp.724-734
• /
• 2016

The purpose of this study was to determine the health behaviors and nutritional status related to dyslipidemia in Korean middle-aged adults (between 50 and 64 years old) from the Korean National Health and Nutrition Examinations Survey data (2007~2010). A total of 4,721 subjects were analyzed in this study. The subjects were divided into three groups (normal, borderline, and dyslipidemia) according to serum lipid levels. Parameters included in this study were drinking and smoking, anthropometric parameters, blood and nutritional parameters. The latter parameter included food/nutrients intake. All data was adjusted by sex, region, education level, and age. General linear model and logistic regression model were used for statistical analysis. The dyslipidemia group was comprised of more men than women. By contrast, the borderline group was comprised of more women than men (p<0.001). No significant differences were observed for other general characteristics. There were more smokers and drinkers(drinking per time) in the dyslipidemia group (p<0.05). Anthropometric data showed significant difference, ie, height (p<0.05), weight, body mass index, waist circumference, percent body fat, and blood pressure were higher in the dyslipidemia group (p<0.001). Only blood urea nitrogen showed no significant difference among groups. The HbA1c (p<0.01), fasting blood glucose, GOT, GPT, creatinine levels were higher in the dyslipidemia group (p<0.001). So it is required for the management of obesity in dyslipidemia group. The dyslipidemia group ate less sea food (p<0.05). The nutrients intake of energy and protein, thiamin, riboflavin, niacin, calcium, phosphorus were lower in the dyslipidemia group (p<0.05). Therefore, to lower dyslipidemia prevalence rates, it is necessary to increase the intake of foods containing ${\omega}-3$ fatty acids. We also suggest a meal management program and nutritional education to recognize the risk of dyslipidemia, especially for people such as the individual in the borderline and dyslipidemia study groups.