• Journal of KIISE:Software and Applications
• /
• v.32 no.7
• /
• pp.663-673
• /
• 2005

An analysis model for the dynamics information of two-dimensional time-series patterns is described. In the proposed model, two novel transforms that visualize the dynamic characteristics are proposed. The first transform, referred to as speed equalization, reproduces a time-series pattern assuming a constant linear velocity to effectively model the temporal characteristics of the signing process. The second transform, referred to as velocity transform, maps the signal onto a horizontal vs. vertical velocity plane where the variation oi the velocities over time is represented as a visible shape. With the transforms, the dynamic characteristics in the original signing process are reflected in the shape of the transformed patterns. An analysis in the context of these shapes then naturally results in an effective analysis of the dynamic characteristics. The proposed transform technique is applied to an online signature verification problem for evaluation. Experimenting on a large signature database, the performance evaluated in EER(Equal Error Rate) was improved to 1.17$\%$ compared to 1.93$\%$ of the traditional signature verification algorithm in which no transformed patterns are utilized. In the case of skilled forgery experiments, the improvement was more outstanding; it was demonstrated that the parameter set extracted from the transformed patterns was more discriminative in rejecting forgeries

• Korean Journal of Remote Sensing
• /
• v.37 no.2
• /
• pp.199-209
• /
• 2021

By removing the increasing trend that long-term time series average of rice yield due to technological advancement of rice variety and cultivation management, we tried to improve the rice yield estimation model which developed earlier using MODIS NDVI and meteorological data. A multiple linear regression analysis was carried out by using the NDVI derived from MYD13Q1 and weather data from 2002 to 2019. The model was improved by analyzing the increasing trend of rime-series rice yield and removing it. After detrending, the accuracy of the model was evaluated through the correlation analysis between the estimated rice yield and the yield statistics using the improved model. It was found that the rice yield predicted by the improved model from which the trend was removed showed good agreement with the annual change of yield statistics. Compared with the model before the trend removal, the correlation coefficient and the coefficient of determination were also higher. It was indicated that the trend removal method effectively corrects the rice yield estimation model.

• Applied Chemistry for Engineering
• /
• v.30 no.2
• /
• pp.247-253
• /
• 2019

In this study, compounds with azo-mesogenic groups at 4-, 3,5-, or 3,4,5-positions of one phenyl ring were synthesized, and their liquid crystallinity and photochemistry were investigated. The compounds in the Azo1 and Azo2 series had linear and planar geometries, respectively, while those in the Azo3 series had relatively bulky structures. Compounds of BA-Azo2 and BA-Azo3 did not show any liquid crystallinity. Compounds of BE-Azo1 and BE-Azo2 exhibited a monotropic liquid crystallinity, while the other compounds showed an enantiotropic liquid crystallinity. The liquid crystalline behavior was imparted by the azo-mesogenic groups, and most of the liquid crystalline compounds formed a smectic phase. All the RM-AzoX compounds exhibited photoisomerism because of the presence of the azo groups in the molecule. The rate of photoisomerization followed the order of RM-Azo3 < RM-Azo1 < RM-Azo2 and was considered to depend on the steric hindrance around the azobenzene groups in the molecule. These results suggest that the liquid crystallinity and photochemical property of the compounds are affected by the position or the number of azo-mesogenic groups phenyl ring of the molecule.

• Journal of Navigation and Port Research
• /
• v.47 no.3
• /
• pp.155-166
• /
• 2023

Trend analysis and time series analysis were conducted to predict the demand of manpower under the smartization of shipping and port logistics with transportation survey data of Statistic Korea during the period from 2000 to 2020 and Statistical Yearbook data of Korean Seafarers from 2004 to 2021. A linear regression model was adopted since the validity of the model was evaluated as the highest in forecasting manpower demand in the shipping and port logistics industry. As a result of forecasting the demand of manpower in autonomous ship, remote ship management, smart shipping business, smart port, smart warehouse, and port logistics service from 2021 to 2035, the demand for smart shipping and port logistics personnel was predicted to increase to 8,953 in 2023, 20,688 in 2030, and 26,557 in 2035. This study aimed to increase the predictability of manpower demand through objective estimation analysis, which has been rarely conducted in the smart shipping and port logistics industry. Finally, the result of this research may help establish future strategies for human resource development for professionals in smart shipping and port logistics by utilizing the demand forecasting model described in this paper.

• Journal of Preventive Medicine and Public Health
• /
• v.38 no.3
• /
• pp.283-290
• /
• 2005

Objectives : The aim of this paper was to examine the relationship between the summertime (June to August) heat index, which quantifies the bioclimatic apparent temperature in sultry weather, and the daily disease-related mortality in Seoul for the period from 1991 to 2000. Methods : The daily maximum (or minimum) summertime heat indices, which show synergetic apparent temperatures, were calculated from the six hourly temperatures and real time humidity data for Seoul from 1991 to 2000. The disease-related daily mortality was extracted with respect to types of disease, age and sex, etc. and compared with the time series of the daily heat indices. Results : The summertime mortality in 1994 exceeded the normal by 626 persons. Specifically, blood circulation-related and cancer-related mortalities increased in 1994 by 29.7% (224 persons) and 15.4% (107 persons), respectively, compared with those in 1993. Elderly persons, those above 65 years, were shown to be highly susceptible to strong heat waves, whereas the other age and sex-based groups showed no significant difference in mortality. In particular, a heat wave episode on the 22nd of July 2004 ($>45^{\circ}C$ daily heat index) resulted in double the normal number of mortalities after a lag time of 3 days. Specifically, blood circulation-related mortalities, such as cerebral infraction, were predominant causes. Overall, a critical mortality threshold was reached when the heat index exceeded approximately $37^{\circ}C$, which corresponds to human body temperature. A linear regression model based on the heat indices above $37^{\circ}C$, with a 3 day lag time, accounted for 63% of the abnormally increased mortality (${\geq}+2$ standard deviations). Conclusions : This study revealed that elderly persons, those over 65 years old, are more vulnerable to mortality due to abnormal heat waves in Seoul, Korea. When the daily maximum heat index exceeds approximately $37^{\circ}C$, blood circulation-related mortality significantly increases. A linear regression model, with respect to lag-time, showed that the heat index based on a human model is a more dependable indicator for the prediction of hot weather-related mortality than the ambient air temperature.

• Membrane Journal
• /
• v.6 no.2
• /
• pp.86-95
• /
• 1996

Rotary disc ultrafiltration module(RDM) was developed for the separation of oil e$$\mu$sions. This module was devised to reduce the gel polarization phenomenon by decoupling the operation pressure and the surface velocity of solution in ultrafiltration(UF) processes. The rotary disc membrane consists of 3mm-thick ABS plate covered with UF membrane (UOP, U.S.A.). When the angular velocity($\omega$) was increased, the pure water flux was slightly decreased due to pressure drop caused by centrifugal force and slip flow at the surface of membrane. The pressure drop was proportional to the square of linear velocity(${\omega}r$). When the angular velocity was changed from 52.36rad/s to 2.62rad/s, the flux decline for 5% cutting oil in one-shaft RDM at $25^{\circ}C$ and 0.1MPa was 30.16%. In the lower concentrations, angular velocity tends to give less effect on the flux. Flux(J; $kg/m^{2} \cdot s$) in a rotating disc module is mainly a function of the bulk concentration($C_{B}$; %), the linear velocity(${\omega}r$; m/s) and the effective transmembrane pressure($\Delta P_{T}$ ; Pa). Using a modified resistance-in-series model, the flux data of cutting oil experiments were fitted to give the following equation.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.3
• /
• pp.82-89
• /
• 2012

This paper presents the intelligent tracking algorithm for maneuvering target using the positional error compensation of the maneuvering target. The difference between measured point and predict point is separated into acceleration and noise. Fuzzy c-mean clustering and predicted impact point are used to get the optimal acceleration value. The membership function is determined for acceleration and noise which are divided by fuzzy c-means clustering and the characteristics of the maneuvering target is figured out. Divided acceleration and noise are used in the tracking algorithm to compensate computational error. The filtering process in a series of the algorithm which estimates the target value recognize the nonlinear maneuvering target as linear one because the filter recognize only remained noise by extracting acceleration from the positional error. After filtering process, we get the estimates target by compensating extracted acceleration. The proposed system improves the adaptiveness and the robustness by adjusting the parameters in the membership function of fuzzy system. To maximize the effectiveness of the proposed system, we construct the multiple model structure. Procedures of the proposed algorithm can be implemented as an on-line system. Finally, some examples are provided to show the effectiveness of the proposed algorithm.

• Fire Science and Engineering
• /
• v.15 no.1
• /
• pp.16-22
• /
• 2001

Thermal properties of PP and LLDPE dusts from chemical plant and their risks of coexisting with oxidizer were investigated by a pressure vessel. The thermal decomposition of PP and LLDPE dusts with temperature using DSC and the weight loss with temperature using TGA were also investigated to find the thermal hazard of PP and LLDPE dusts. Using the pressure vessel which can estimate ignition and explosion of PP and LLDPE dusts coexisting with oxidizer, a series of bursting of a rupture disc, experiments has been conducted by varying the orifice diameters the weight ratio of the sample coexisting with oxidizers and the species of oxidizer. And fire gases was measured by gas analyser ($ECOM-A^+$). According to the results of the thermal analysis of PP and LLDPE dusts, the decomposition temperature range of PP and LLDPE dusts was 200 to 350 and 300 to $500^{\circ}c$, respectively. The risk of PP and LLDPE dusts coexisting with oxidizer was increased as the orifice diameter was decreased. On the other hand, it was increased as the weight ratio of the sample to the oxidizer were increased. In addition, the risk of PP and LLDPE dusts coexisting with oxidizer was affected by the decomposition temperature of the sample and oxidizer. It is found that the risk of fire becomes high when the decomposition temperature of the sample is about same as that of oxidizer. Also, the fire gases was occurred carbon monoxide and carbon dioxide. The amount of carbon monoxide generated was found to be much higher in PP decomposition than in LLDPE due to incomplete combustion of PP which has high content of carbon in chemical compound.

• Asian Journal of Turfgrass Science
• /
• v.23 no.1
• /
• pp.77-90
• /
• 2009

Near Infrared Reflectance Spectroscopy(NIRS) is a quick, accurate, and non-destructive method to measure multiple nutrient components in plant leaves. This study was to acquire a liner regression equation by evaluating the nutrient contents of 'CY2' creeping bentgrass rapidly and accurately using NIRS. In particular, nitrogen fertility is a primary element to keep maintaining good quality of turfgrass. Nitrogen, moisture, carbohydrate, and starch were assessed and analyzed from 'CY2' creeping bentgrass clippings. A linear regression equation was obtained from accessing NIRS values from NIR spectrophotometer(NIR system, Model XDS, XM-1100 series, FOSS, Sweden) programmed with WinISI III project manager v1.50e and ISIscan(R) (Infrasoft International) and calibrated with laboratory values via chemical analysis from an authorized institute. The equation was formulated as MPLS(modified partial least squares) analyzing laboratory values and mathematically pre-treated spectra. The accuracy of the acquired equation was confirmed with SEP(standard error of prediction), which indicated as correlation coefficient($r^2$) and prediction error of sample unacquainted, followed by the verification of model equation of real values and these monitoring results. As results of monitoring, $r^2$ of nitrogen, moisture, and carbohydrate in 'CY2' creeping bentgrass was 0.840, 0.904, and 0.944, respectively. SEP was 0.066, 1.868, and 0.601, respectively. After outlier treatment, $r^2$ was 0.892, 0.925, and 0.971, while SEP was 0.052, 1.577, and 0.394, respectively, which totally showed a high correlation. However, $r^2$ of starch was 0.464, which appeared a low correlation. Thereof, the verified equation appearing higher $r^2$ of nitrogen, moisture, and carbohydrate showed its higher accuracy of prediction model, which finally could be put into practical use for turf management system.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.9
• /
• pp.87-92
• /
• 2014

The Ground anchor is reinforcement to resist pull-out through ground that is used supports structure. The pull-out resistance of anchor is constructed by skin friction resistance from compression borehole wall in expanded wings and bearing pressure from the ground. Especially, underreamed ground anchor is reinforcement that adopts active reinforcement to prevent deformation of ground using bearing resistance generated reaming anchorage. This study is conducted to calculate bearing resistance of underreamed ground anchor. Realistic model tests were fulfilled to determine bearing resistance of anchor, and correlate results of tests to Uniaxial Compressive Strengths (UCS) of ground models that assumed weathered rock condition in 8 case. In a comprehensive series of the tests, the bearing resistances were measured by pull-out tests. The bearing resistances derived from tests have a linear correlation with UCS. We also suggest empirical equation between bearing resistance and UCS of rocks by single linear regression analyses. In test results of this study, the bearing resistances were evaluated approximately 13 times higher than UCS of the grounds, and it is qualitatively similar to numerical values of pull-out force derived from theory.