• 한국항행학회논문지
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• 제16권6호
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• pp.927-934
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• 2012

본 논문은 저가의 GPS 수신기와 MEMS급 IMU, B-CDMA 무선 통신 모듈을 이용한 다수 차량의 상대위치 추정에 관한 연구이다. 차량의 상대위치를 추정함에 있어서, 각 차량의 가시 위성 조합이 불일치 할 경우 오차가 급증하는 현상이 발생한다. 본 논문에서는, 이를 개선하기 위하여 측정치 기반으로 상대위치를 계산하는 RGPS 알고리즘을 제안한다. 동시에 GPS/INS 통합 항법 알고리즘을 적용하여 각 차량의 방향각과 속도를 추정한다. 최종적으로 RGPS 알고리즘과 각 차량의 GPS/INS 통합항법 알고리즘 결과를 사용한 Position Integration Filter 알고리즘으로부터 최종적인 상대위치와 상대속도를 추정한다. 이와 같은 연구 결과를 증명하기 위하여 실제 실험을 통하여 추정 결과를 확인하였다. 실시간 프로그램과 실험용 모형 차량을 제작하여 상대위치, 상대속도 추정 실험을 실시, 실제 환경에서의 알고리즘의 성능을 검증하였다.

• 보건행정학회지
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• 제29권3호
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• pp.303-311
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• 2019

Background: Cerebrovascular disease is included in four major diseases and is a disease that has high rates of prevalence and mortality around the world. Moreover, it is a disease that requires a high cost for long-term hospitalization and treatment. This study aims to figure out the correlation between grip strength, which was presented as a simple, cost-effective, and relevant predictor of cerebrovascular disease, and cerebrovascular disease based on the results of a prior study. And furthermore, our study compared model suitability of the model to measuring grip strength and relative grip strength as a predictor of cerebrovascular disease to improve the quality of cerebrovascular disease's predictor. Methods: This study conducted an analysis based on the generalized linear mixed model using the data from the Korea Longitudinal Study of Ageing from 2006 to 2016. The research subjects consisted of 9,132 middle old age people aged 45 years or older at baseline with no missing information of education level, gender, marital status, residential region, type of national health insurance, self-related health, smoking status, alcohol use, and economic activity. The grip strength was calculated the average which measured 4 times (both hands twice), and the relative grip force was divided by the body mass index as a variable considering the anthropometric figure that affects the cerebrovascular disease and the grip strength. Cerebrovascular diseases, a dependent variable, were investigated based on experiences diagnosed by doctors. Results: An analysis of the association between grip strength and found that about 0.972 (odds ratio [OR], 0.972; 95% confidence interval [CI], 0.963-0.981) was the incidence of cerebral vascular disease as grip strength increased by one unit increase and the association between relative grip strength and cerebrovascular disease found that about 0.418 (OR, 0.418; 95% CI, 0.342-0.511) was the incidence of cerebral vascular disease as relative grip strength increased by unit. In addition, the model suitability of the model for each grip strength and relative grip strength was 11,193 and 11,156, which means relative grip strength is the better application to the predictor of cerebrovascular diseases, irrespective of other variables. Conclusion: The results of this study need to be carefully examined and validated in applying relative grip strength to improve the quality of predictors of cerebrovascular diseases affecting high mortality and prevalence.

• 한국초지조사료학회지
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• 제15권1호
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• pp.30-36
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• 1995

Pasture composed of about 30% botanical composition of white clover (Trijolium repem L.) is desirable in its productivity and quality. To get information on maintaining its productivity in the pasture, the experiment was canied out to determine the effect of infrequent, frequent defoliation or their alternation on change of its harvest yield and growth. Individual plants of Regal, Louisiana S-1, Grasslands Huia and Aberystwyth S184 were grown in 22cm plastic pot containing a 2 : 1 : 1 soil : sand : Peat moss mixture for 27 days after transplanting 50day seedlings raised on 3cm pots, and then all their fully expanded leaves are removed. Defoliation treatments were forced every 1 (CC, frequent), 4 week (RR, infrequent) or their alternations (CR, RC) after 8 weeks from the removal. To analyze the treatment effects, plants were sampled on 0 (the removal day), 4, 8, 12 and 16 weeks after the removal and seperated to leaves, petioles, stolons and roots. Each harvest yield of infrequent defoliation (RR) was higher than that of frequent defoliation (CC). Their alternations (RC, CR), however, forced fluctuation of the yield according to defoliation interval. Fraction weights from their altemations showed intermediate ones of infrequent and Frequent defoliation whose weights did the similar result to their harvest yields. Fraction and total dry weights per plant, shoot/root ratio were changed by relative span of defoliation interval, which resulted from the weights of leaves and petioles, removed parts. Root and total dry weight per plant of Regal were greater than the other cultivm in infrequent defoliation interval regardless of continuous or alternations. Productivity of white clover in pasture, therefore, can be controlled by alternation of infrequent and frequent defoliation or reverse.

• 한국물환경학회지
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• 제37권2호
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• pp.103-113
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• 2021

In this study, an Excel-based model (ROADMOD) was developed to estimate pollutant loading from the road and evaluate BMPs. ROADMOD employs the Chezy-Manning equation and empirical expression for estimating surface runoff, and power function for pollutant buildup, and exponential function for pollutant washoff in SWMM. The results of model calibration for buildup and washoff using observed data revealed a good match between the simulation results and the observed data. The long-term surface runoff and sediment simulated by ROADMOD demonstrated a good match with those by SWMM with 2 ~ 14% of relative error. The shorter sweeping interval (within 8 days) remarkably decreased sediment loads from the road. It was found that the effect of reducing sediment loads from the road was greatly affected not only by the sweeping interval but also by sweeping on the day before a rainfall event. The 48% of removal efficiency of sediment loads from the road was achieved with 26 times of road sweeping per year when sweeping was performed on the day before the rainfall event. A 4-day sweeping interval showed similar removal efficiency (48%) with 96 times of sweeping per year. It is considered that the road sweeping on the day before a rainfall event could maximize the effect of reducing the non-point source pollution from the road with minimization of the number of road sweeping. So, the road sweeping on the day before a rainfall event can be considered as one of the useful and best management practices (BMPs) on road.

• 한국임상약학회지
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• 제21권2호
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• pp.90-99
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• 2011

Health Insurance Review & Assessment Service (HIRA) claims database has a high potential to detect signals of new drug interactions. The aim of this study was to evaluate the usefulness of information component (IC) and relative risk (RR) as a tool for signal detection, and to analyze the possible drug interactions caused by clopidogrel using HIRA claims database. This study was performed in elderly patients over 65 years of age who administered clopidogrel from January 2005 to June 2006 in South Korea. Serious Adverse Events (SAEs) as drug interactions of clopidogrel were defined as any ambulatory hospitalization for ischemic diseases within comcomitant medication period of clopidogrel. Information Component (IC) and Relative Risk (RR) were calculated to compare the proportion of drug-SAE pairs in order to select drug specific SAEs. IC and RR signals of clopidogrel drug interaction were screened when IC's 95% confidence interval was greater than 0 and RR's 95% confidence interval was greater than 1 respectively. All detected signals were compared to references such as $Micromedex^{(R)}$ and 2010 Drug Interaction $Facts^{TM}$. Sensitivity, specificity, positive predicted value and negative predicted value were used to evaluate usefulness of this method. Among 13,252,930 cases of elderly patients who co-administered clopidogrel and other drugs, 47,485 cases were detected as SAE. Of these, one-hundred nine cases were detected by the IC-based data-mining approach and ninety one cases were detected by the RR-based data-mining approach. Total One-hundred sixty three unrecognized signals were detected by IC or RR. Twelve signals from IC-based data-mining (57.1%) were corresponded with drug interactions from references and eight signals from RR-based data-mining (38.1%) were corresponded with drug interactions from references. These signals include proton pump inhibitors, calcium channel blockers and HMG CoA reductase Inhibitors, which were known to affect CYP450 metabolism. Further studies using HIRA claims database are necessary to develop appropriate data-mining measure.

• 한국농공학회지
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• 제40권2호
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• pp.59-68
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• 1998

This study was conducted to derive optimal design floods by generalized gamma distribution model of the annual maximum series at eight watersheds along Geum, Yeongsan and Seomjin river systems. Design floods obtained by different methods for evaluation of parameters and for plotting positions in the generalized gamma distribution model were compared by the relative mean errors and graphical fit along with 95% confidence limits plotted on gamma probability paper. The results were analyzed and summarized as follows. 1. Basic statistics and parameters were calculated by the generalized gamma distribution model using different methods for parameters. 2. Design floods according to the return periods were obtained by different methods for evaluation of parameters and for plotting positions in the generalized gamma distribution model. 3. It was found that design floods derived by sundry averages method for parameters and Cunnane method for plotting position in the generalized gamma distribution are much closer to those of the observed data in comparison with those obtained by the other methods for parameters and for plotting positions from the viewpoint of relative mean errors. 4. Reliability of design floods derived by sundry averages method in the generalized gamma distribution was acknowledged within 95% confidence interval.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.79-81
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• 2006

Geostationary ocean satellite, unlike other sun-synchronous polar-orbit satellites, will be able to take a picture of a large region several times a day (almost with every one hour interval). For geostationary satellite, the target region is fixed though the location of sun is changed always. Thus, the ocean signal of a given target point is largely dependent on time. In other words, the ocean signal detected by geostationary satellite sensor must translate to the signal of target when both sun and satellite are located in nadir, using another correction model. This correction is performed with a standardization of signal throughout relative geometric relationship among satellite - sun - target points. One signal value of a selected pixel point of the target region of Geostationary Ocean Colour Imager (GOCI) would be set up as a standard, and the ratio of all remained pixel point can be calculated. This relative ratio called bidirectional factor, the result of modelling of spatiotemporal variation of bidirectional factor is shown.

• The Plant Pathology Journal
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• 제28권2호
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• pp.172-184
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• 2012

An infection risk model for Phytophthora blight on chili pepper was developed to estimate the first date of disease occurrence in the field. The model consisted of three parts including estimation of zoosporangium formation, soil water content, and amount of active inoculum in soil. Daily weather data on air temperature, relative humidity and rainfall, and the soil texture data of local areas were used to estimate infection risk level that was quantified as the accumulated amount of active inoculum during the prior three days. Based on the analysis on 190 sets of weather and disease data, it was found that the threshold infection risk of 224 could be an appropriate criterion for determining the primary infection date. The 95% confidence interval for the difference between the estimated date of primary infection and the observed date of first disease occurrence was $8{\pm}3$ days. In the model validation tests, the observed dates of first disease occurrence were within the 95% confidence intervals of the estimated dates in the five out of six cases. The sensitivity analyses suggested that the model was more responsive to temperature and soil texture than relative humidity, rainfall, and transplanting date. The infection risk model could be implemented in practice to control Phytophthora blight in chili pepper fields.

• Steel and Composite Structures
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• 제37권5호
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• pp.571-587
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• 2020

In this article the seismic demand and performance of two recent braced steel frames named steel moment frames with the elliptic bracing (ELBRFs) are assessed through a laboratory program and numerical analyses of FEM. Here, one of the specimens is without connecting bracket from the corner of the frame to the elliptic brace (ELBRF-E), while the other is with the connecting brackets (ELBRF-B). In both the elliptic braced moment resisting frames (ELBRFs), in addition to not having any opening space problem in the bracing systems when installed in the surrounding frames, they improve structure's behavior. The experimental test is run on ½ scale single-story single-bay ELBRF specimens under cyclic quasi-static loading and compared with X-bracing and SMRF systems in one story base model. This system is of appropriate stiffness and a high ductility, with an increased response modification factor. Moreover, its energy dissipation is high. In the ELBRF bracing systems, there exists a great interval between relative deformation at the yield point and maximum relative deformation after entering the plastic region. In other words, the distance from the first plastic hinge to the collapse of the structure is fairly large. The experimental outcomes here, are in good agreement with the theoretical predictions.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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• pp.174-181
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• 1998

A prospective study was conducted to evaluate the preventive effect of Korean ginseng against cancer in the population residing ginseng cultivation area, Kangwha-eup from August 1987 to December 1997. The participants consisted of 4,553 adults over 40 years old who completed a questionare on ginseng intake. During the surveillance period, 14.4% (656 of 4,553) of subjects had died, cancer accounting for 23.9% (157) of total deaths. The proportional hazard model of Cox was used to estimate relative risks when controlling simultaneously for covariates. Ginseng intakers had a decreased risk (relative risk(RR) =0.48, 95% confidence interval (Cl) : 0.34-0.66) for cancer compared with non-intakers. The RRs of cancer were 0.36 (95% Cl: 0.24-0.56) for multiple combination intakers. Among 24 red ginseng intakers, there were no cancer deaths. The RRs of ginseng intakers were 0.38 (95% Cl: 0.20-0.71) in gastric cancer and 0.29 (95% Cl: 0.15- 0.57) in lung cancer. These findings strongly suggested Korean ginseng have non-organ specific cancer preventive effects against cancer. Further research for clarifying the mechanisms of prevention and clinical trials on Korean ginseng must be conducted with worldwide collaborations