• Communications for Statistical Applications and Methods
• /
• v.4 no.3
• /
• pp.847-858
• /
• 1997

In this note we develop a partial ordering among positive lower orthant dependent distributions with fixed marginals. This permits us to measure the degree of positive lower orthant dependence. Some basic properties and preservation results are derived.

• Ocean Systems Engineering
• /
• v.9 no.3
• /
• pp.287-328
• /
• 2019

Comprehensive understanding of the flood risk assessments via frequency analysis often demands multivariate designs under the different notations of return periods. Flood is a tri-variate random consequence, which often pointing the unreliability of univariate return period and demands for the joint dependency construction by accounting its multiple intercorrelated flood vectors i.e., flood peak, volume & durations. Selecting the most parsimonious probability functions for demonstrating univariate flood marginals distributions is often a mandatory pre-processing desire before the establishment of joint dependency. Especially under copulas methodology, which often allows the practitioner to model univariate marginals separately from their joint constructions. Parametric density approximations often hypothesized that the random samples must follow some specific or predefine probability density functions, which usually defines different estimates especially in the tail of distributions. Concentrations of the upper tail often seem interesting during flood modelling also, no evidence exhibited in favours of any fixed distributions, which often characterized through the trial and error procedure based on goodness-of-fit measures. On another side, model performance evaluations and selections of best-fitted distributions often demand precise investigations via comparing the relative sample reproducing capabilities otherwise, inconsistencies might reveal uncertainty. Also, the strength & weakness of different fitness statistics usually vary and having different extent during demonstrating gaps and dispensary among fitted distributions. In this literature, selections efforts of marginal distributions of flood variables are incorporated by employing an interactive set of parametric functions for event-based (or Block annual maxima) samples over the 50-years continuously-distributed streamflow characteristics for the Kelantan River basin at Gulliemard Bridge, Malaysia. Model fitness criteria are examined based on the degree of agreements between cumulative empirical and theoretical probabilities. Both the analytical as well as graphically visual inspections are undertaken to strengthen much decisive evidence in favour of best-fitted probability density.

• Journal of the Korean earth science society
• /
• v.26 no.2
• /
• pp.109-113
• /
• 2005

In this study, the estimation of the temperature distribution of Jeju Island with coastal ocean derived from the thermal band of Landsat 7/ETM+ of January 6, 2003 was carried out. For the computation of the temperature of the island and the coastal ocean based on the thermal band, we used NASA method wiich is the 8 bit Digital Number(DN) converted into spectral radiance. The computed results showed that the land temperature variations were from 0 to 12 Celsius degrees, and a good agreement with the observation ones based on the method. However, the ocean surface temperature was not much changed ground 15 degree since the water was well mixed between the coastal and the offshore ocean. The interesting results were that the temperature distributions of the southern part(Seogwipo City) of Jeju Island were higher than those of the north one(Jeju City) by more than 2 Celsius degree at the same height although the distance between the Jeju and the Seogwipo is only about 35km in winter season. The reason was found that the solar irradiance intensity of the south part was stronger than the north one by Halla mountain in winter season only. From the results, we found that the seasonal variations of solar irradiation and the height of Mt. Halla were an important role of temperature distribution of Jeju Island.

• Earthquakes and Structures
• /
• v.3 no.3_4
• /
• pp.413-434
• /
• 2012

This paper presents a displacement-based seismic design method with damage control, in which the targets for the considered performance level are set as displacements and a damage distribution is proposed by the designer. The method is based on concepts of basic structural dynamics and of a reference single degree of freedom system associated to the fundamental mode with a bilinear behaviour. Based on the characteristics of this behaviour curve and on the requirements of modal spectral analysis, the stiffness and strength of the structural elements of the structure satisfying the target design displacement are calculated. The formulation of this method is presented together with the formulations of two other existing methods currently considered of practical interest. To illustrate the application of the proposed method, 5 reinforced concrete plane frames: 8, 17 and 25 storey regular, and 8 and 12 storey irregular in elevation. All frames are designed for a seismic demand defined by single earthquake record in order to compare the performances and damage distributions used as design targets with the corresponding results of the nonlinear step by step analyses of the designed structures subjected to the same seismic demand. The performances and damage distributions calculated with these analyses show a good agreement with those postulated as targets.

• Earthquakes and Structures
• /
• v.25 no.6
• /
• pp.455-467
• /
• 2023

This study focuses on demonstrating the effectiveness of vibration control of tuned rotary mass damper (TRMD) for reducing the bidirectional and torsional response of the irregular asymmetric structure with voided slabs under earthquake excitations. The TRMD arranged in plane of one-story eccentric structure is proposed as a distributed tuned rotary mass damper (DTRMD) system. Lagrange's equation is used to derive the equations of motion of the controlled system. The optimum position and number of TRMD are numerically investigated under harmonic excitation and the control effects of different distributions are discussed. Furthermore, a shaking table test is conducted under different excitation cases, including free vibration, forced vibration and seismic wave to investigate the absorption performance of the device. The numerical simulations of different distributions of the TRMDs show that the DTRMDs are more effective in reduction of the displacement response of the asymmetric structure under the same mass ratio, even when the degree of eccentricity becomes large. However, with small degree of eccentricity, the unreasonable asymmetrical arrangement may cause the increase of the peak value of the rotational angular displacement. Finally, the experimental investigations exhibit similar results of translational displacement of the structure. It is concluded that the vibration of the irregular asymmetric structure can be controlled more economically and effectively by reducing the mass ratio through reducing the quantity of TRMDs at the high stiffness end.

• Journal of the Korean Institute of Navigation
• /
• v.17 no.4
• /
• pp.43-51
• /
• 1993

The purposes of this study are to make an analysis the sensible degree in Korea by using the formulas prepared by Watanabe, and to divide the climatic classification by the sensible degree in order to apply in practical life. Most data(air temperature, relative humidity, wind velocity, atmospheric pressure) are extracted from the "Climatic Table of Korea, Volume II(1961~1990)" issued by the Korea Meteorological Administration. As a result of this study, distribution patterns of the sensible degree are similar to isotherms when the wind velocity is zero, and then the sensible degrees are reduced with the increase of latitude. And western coastal and inland regions have larger values than eastern coastal regions in summer. However, the cont-rary distributions are shown in winter. When the wind velocity is not zero, distribution patterns of the sensible degree are influenced by the wind velocity. In summer, the values of central and southern inland regions are especially higher than the coastal regions, and most northern districts and some inland regions (Kangnung, Ulchin, Yongju etc.) have low values in winter. Then, the climate of Korea is divided into four patterns as follows : Yow means the sensible degree when the wind velocity is zero in winter. Yow > 3 : Jeju Island and southern coastal regions Yow = 0~3 : Most southern district and eastern coastal regions of central districts Yow = -3~0 : Most central districts and some eastern coastal regions (Hamheung, Youngheung, Won-san etc.) of northern districts Yow < -3 : Most northern districts and some inland regions(Inje, Hongcheon, Yang-pyeong etc.) of cent-ral districts.districts.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.7
• /
• pp.79-90
• /
• 1999

This investigation presents the experimental results of forced convection boiling heat transfer around a circular, electrically heated horizontal cylinder to subcooled water in cross flow. In these experiments, the following primary variables were included: heat flux, flow velocity, pressure and degree of subcooling at inlet. Local surface temperatures were measured at nine peripheral positions. Local surface temperature distributions are classified into four categories depending on the supplied heat flux. The effects of the boiling curve depending on the fluid velocity, degree of subcooling at inlet and pressure are presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.686-691
• /
• 2010

Flash boiling takes place when the thermodynamic state of the liquid deviates from its saturation limit over which the liquid temperature exceeds by a certain degree of superheat. The liquid jet introduced into the lower pressure zone than the liquid saturation pressure experiences a sequence of the atomization and disintegrated into numerous faster and smaller droplets. In the present study spray characteristics for a flash swirl spray were experimentally investigated. Injectant temperature is raised by a high frequency dielectric heating method and local spray characteristics are instantly measured by Global Sizing Velocimetry (GSV, TSI Inc.). Dependence of dimensionless superheat degree and injection pressure on total and local SMDs and mean droplet size is quantitatively examined. The flash swirl spray has the relation in the injection pressure and nozzle diameter in order to determine the spray quality, including the dimensionless superheat degree. Small droplets occur in the void core and local droplet size distributions largely depend on the dimensionless superheat degree and the injection pressure.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2006.04a
• /
• pp.55-56
• /
• 2006

This thesis describes the use of measured aerosol size distributions and size-resolved hygroscopic growth to examine the physical and chemical properties of several particle classes. The primary objective of this work was to investigate the optical and cloud forming properties of a range of ambient aerosol types measured in a number of different locations. The tool used for most of these analyses is a differential mobility analyzer / tandem differential mobility analyzer (DMA / TDMA) system developed in our research group. To collect the data described in two of the chapters of this thesis, an aircraft-based version of the DMA / TDMA was deployed to Japan and California. The data described in two other chapters were conveniently collected during a period when the aerosol of interest came to us. The unique aspect of this analysis is the use of these data to isolate the size distributions of distinct aerosol types in order to quantify their optical and cloud forming properties. I used collected data during the Asian Aerosol Characterization Experiment (ACE-Asia) to examine the composition and homogeneity of a complex aerosol generated in the deserts and urban regions of China and other Asian countries. An aircraft-based tandem differential mobility analyzer was used for the first time during this campaign to examine the size-resolved hygroscopic properties of particles having diameters between 40 and 586 nm. Asian Dust Above Monterey (ADAM-2003) study was designed both to evaluate the degree to which models can predict the long-range transport of Asian dust, and to examine the physical and optical properties of that aged dust upon reaching the California coast. Aerosol size distributions and hygroscopic growth are measured in College Station, TX to investigate the cloud nucleating and optical properties of a biomass burning aerosol generated from fires on the Yucatan Peninsula. Measured aerosol size distributions and size-resolved hygroscopicity and volatility were used to infer critical supersaturation distributions of the distinct particle types that were observed during this period. The predicted CCN concentrations were used in a cloud model to determine the impact of the different aerosol types on the expected cloud droplet concentration. RH-dependent aerosol extinction coefficients are calculated at a wavelength of 550 nm.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.11
• /
• pp.723-729
• /
• 2014

In this paper, we derive the average repair bandwidth and/or read cost for arbitrary repairable linear code ensembles. The repair bandwidth and read cost are the required amount of data and access number of nodes to restore a failed node, respectively. Here, the repairable linear code ensemble is given by such parameters as the number k of data symbols, the number m of parity symbols, and their degree distributions. We further assume that the code is systematic, and no other constraint is assumed, except possibly that the exact repair could be done by the parity check-sum relation with fully connected n=k+m storages. This enables one to apply the result of this paper directly to any randomly constructed codes with the above parameters, such as linear fountain codes. The final expression of the average repair read cost shows that it is highly dependent on the degree distribution of parity symbols, and also the values n and k.