• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3821-3828
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• 2000

Many software projects collect grouped failure data (failures in some failure interval or in variable time interval) rather than individual failure times or failure count data during the testing or operational phase. This paper presents the neural network (NN) modeling that is dble to predict cumulative failures in the variable future time for grouped failure data. ANN's predictive ability can be affected by what it learns and in its ledming sequence. Eleven training regimes that represents the input-output of NN are considered. The best training regimes dre selected rJdsed on the next' step dvemge reldtive prediction error (AE) and normalized AE (NAE). The suggested NN models are compared with other well-known KN models and statistical software reliability growth models (SHGlvls) in order to evaluate performance, Experimental results show that the NN model with variable time interval information is necessary in order to predict cumulative failures in the variable future time interval.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.2
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• pp.119-123
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• 1999

Background and Objectives : Conditions such as muscle atrophy, stretching of strap muscles, and continued craniofacial growth factors have been cited as contributing to the changes observed in the vocal tract structure and function in elderly speakers. The purpose of the present study is to compare F$_1$ and F$_2$ frequency levels in elderly and young adult male and female speakers producing a series of vowels ranging from high-front to low-back placement. Material and Methods : The subjects were two groups of young adults(10 males, 10 females, mean age 21 years old range 19-24 years) and two groups of elderly speakers(10 males, 10 females, mean age 67 years : range 60-84 years). Each subject participated in speech pathologist to be a speaker of unimpared standard Korean. The headphone was positioned 2 cm from the speakers lips. Each speaker sustained the five vowels for 5 s. Formant frequency measures were obtained from an analysis of linear predictive coding in CSL model 4300B(Kay co). Results : Repeated measure AVOVA procedures were completed on the $F_1$ and $F_2$ data for the male and female speakers. $F_2$ formant frequency levels were proven to be significantly lower fir elderly speakers. Conclusions : We presume $F_2$ vocal cavity(from the point of tongue constriction to lip) lengthening in elderly speakers. The research designed to observe dynamic speech production more directly will be needed.

• The Journal of Bigdata
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• v.5 no.1
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• pp.181-188
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• 2020

As the size of the airport terminal grows in line with the rapid growth of aviation passengers, the advanced baggage handling system that combines various data technologies has become an essential element in order to handle the baggage carried by passengers swiftly and accurately. Therefore, this study introduces the method of analyzing the baggage handling capacity of domestic airports through the latest data analysis methodology from the process point of view to advance the operation of the airport BHS and the main points based on event log data. By presenting an accurate load prediction method, it can lead to advanced BHS operation strategies in the future, such as the preemptive arrangement of resources and optimization of flight-carrousel scheduling. The data used in the analysis utilized the APIs that can be obtained by searching for "Korea Airports Corporation" in the public data portal. As a result of applying the method to the domestic airport BHS simulation model, it was possible to confirm a high level of predictive performance.

• Journal of the Korea Society of Computer and Information
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• v.26 no.4
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• pp.189-195
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• 2021

The point of this research is verifing the longitudinal changes in youth multicultural acceptance and to verify predictive variables of multicultural acceptance. Among the Korean Children and Youth Panal data collected by the Korea Institute for Children and Youth Policy, 1,972 data from the 3rd, 5th, and 6th data of the first-year middle school panal were used, and the data were analyzed by applying the latent growth model, and the following analysis results were obtained. First, adolescents' multicultural acceptability showed an increasing pattern, and the extent of the increase was large at the point of transition from the 3rd year(3rd year of middle school) to the 5th year. Second, predicting the change of multicultural acceptability were found to be significant in the initial values of peer communication, community consciousness and in the rate of change, life-satisfaction, peer communication, community consciousness. This study proposed some plans to improve multicultural acceptance in adolescence basing on these results.

• Journal of Gastric Cancer
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• v.23 no.2
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• pp.289-302
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• 2023

Purpose: Liver metastasis (LM) is reported in approximately 40% of patients with advanced/metastatic gastric/gastroesophageal junction adenocarcinoma (metastatic esophagogastric adenocarcinoma; mGEA) and is associated with a worse prognosis. This post-hoc analysis from the RAINBOW trial reported the efficacy, safety, and biomarker outcomes of ramucirumab and paclitaxel combination treatment (RAM+PAC) in patients with (LM+) and without (LM-) LM at baseline. Materials and Methods: Patients (n=665) were randomly assigned on a 1:1 basis to receive either RAM+PAC (LM+: 150, LM-: 180) or placebo and paclitaxel (PL+PAC) (LM+: 138, LM-: 197). The overall survival (OS) and progression-free survival (PFS) were evaluated using stratified Kaplan-Meier and Cox regression models. The correlation of dichotomized biomarkers (VEGF-C, D; VEGFR-1,2) with efficacy in the LM+ versus LM- subgroups was analyzed using the Cox regression model with reported interaction P-values. Results: The presence of LM was associated with earlier progression than those without LM, particularly in patients receiving PL+PAC (hazard ratio [HR], 1.68). RAM+PAC treatment improved OS and PFS irrespective of LM status but showed greater improvement in LM+ than that in LM- (OS HR, 0.71 [LM+] vs. 0.88 [LM-]; PFS HR, 0.47 [LM+] vs. 0.76 [LM-]). Treatment-emergent adverse events were similar between patients with and without LM. No predictive relationship was observed between biomarker levels (VEGF-C, D; VEGFR-1,2) and efficacy outcome (OS, PFS) (all interaction P-values >0.05). Conclusions: RAM provided a significant benefit, irrespective of LM status; however, its effect was numerically stronger in patients with LM. Therefore, RAM+PAC is a clinically meaningful therapeutic option for patients with mGEA and LM.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.141-150
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• 2008

The response of grain yield(GY) and milled-rice protein content(PC) to crop growth status and nitrogen(N) rates at panicle initiation stage(PIS) is critical information for prescribing topdress N rate at PIS(Npi) for target GY and PC. Three split-split-plot experiments including various N treatments and rice cultivars were conducted in Experimental Farm, Seoul National University, Korea in 2003-2005. Shoot N density(SND, g N in shoot $m^{-2}$) and canopy reflectance were measured before N application at PIS, and GY, PC, and SND were measured at harvest. Data from the first two years(2003-2004) were used for calibrating the predictive models for GY, PC, and SND accumulated from PIS to harvest using SND at PIS and Npi by multiple stepwise regression. After that the calibrated models were used for calculating N requirement at PIS for each of nine plots based on the target PC of 6.8% and the values of SND at PIS that was estimated by canopy reflectance method in the 2005 experiment. The result showed that SND at PIS in combination with Npi were successful to predict GY, PC, and SND from PIS to harvest in the calibration dataset with the coefficients of determination ($R^2$) of 0.87, 0.73, and 0.82 and the relative errors in prediction(REP, %) of 5.5, 4.3, and 21.1%, respectively. In general, the calibrated model equations showed a little lower performance in calculating GY, PC, and SND in the validation dataset(data from 2005) but REP ranging from 3.3% for PC and 13.9% for SND accumulated from PIS to harvest was acceptable. Nitrogen rate prescription treatment(PRT) for the target PC of 6.8% reduced the coefficient of variation in PC from 4.6% in the fixed rate treatment(FRT, 3.6g N $m^{-2}$) to 2.4% in PRT and the average PC of PRT was 6.78%, being very close to the target PC of 6.8%. In addition, PRT increased GY by 42.1 $gm^{-2}$ while Npi increased by 0.63 $gm^{-2}$ compared to the FRT, resulting in high agronomic N-use efficiency of 68.8 kg grain from additional kg N. The high agronomic N-use efficiency might have resulted from the higher response of grain yield to the applied N in the prescribed N rate treatment because N rate was prescribed based on the crop growth and N status of each plot.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.1
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• pp.127-140
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• 1988

The management of sewage and rainfall runoff becomes an emerging problem with the growth of urban communities. From the uncontrollable excess intensity or amount of rainfall, the conditions of sewer surcharge or manhole overflow could be generated in the combined sewer network where municipal or industrial wastewaters and rainfall runoff flow. The predictive model far the prevention of property and human life losses from this inundation was studied in this research. In the development of a mathematical flow model for the combined sewer surcharge and overflow, the Preissmann Slot concept and the four-point implicit method of finite difference were utilized. For the usage in personal computer, the overlapping segment method that required less memory storage was adopted. Through the simulation of hypothetical sewer network, the conservation of discharge volume was checked, and the usefulness of the Preissmann Slot was assured from the temporal distribution of discharge and depth along the sewer network. Also the possible field application for the correction of sewer diameters and slopes in the design of sewer network which has no surcharge/overflow condition was suggested.

• Journal of Life Science
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• v.33 no.6
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• pp.490-497
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• 2023

Pregnant women may need to take medications to treat preexisting diseases or diseases that develop during pregnancy. However, some drugs may be fetotoxic and lead to, for example, teratogenicity and growth retardation. Predicting the fetotoxicity of drugs is thus important for the health of the mother and fetus. The fetotoxicity of many drugs has not been established because various challenges hinder the ability of researchers to determine their fetotoxicity. The need exists for in silico-based fetotoxicity assessment models, as they can modernize the testing paradigm, improve predictability, and reduce the use of animals and the costs of fetotoxicity testing. In this study, we collected data on the fetotoxicity of drugs and constructed fetotoxicity prediction models based on various machine learning algorithms. We optimized the models for more precise predictions by tuning the hyperparameters. We then performed quantitative performance evaluations. The results indicated that the constructed machine learning-based models had high performance (AUROC >0.85, AUPR >0.9) in fetotoxicity prediction. We also analyzed the feature importance of our model's predictions, which could be leveraged to identify the specific features of drugs that are strongly associated with fetotoxicity. The proposed model can be used to prescreen drugs and drug candidates at a lower cost and in less time. It provides a predictive score for fetotoxicity risk, which may be beneficial in the design of studies on fetotoxicity in human pregnancy.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.484-491
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• 2005

Quantitative microbial risk assessment (QMRA) analyzes potential hazard of microorganisms on public health and offers structured approach to assess risks associated with microorganisms in foods. This paper addresses specific risk management questions associated with Staphylococcus aureus in kimbab and improvement and dissemination of QMRA methodology, QMRA model was developed by constructing four nodes from retail to table pathway. Predictive microbial growth model and survey data were combined with probabilistic modeling to simulate levels of S. aureus in kimbab at time of consumption, Due to lack of dose-response models, final level of S. aureus in kimbeb was used as proxy for potential hazard level, based on which possibility of contamination over this level and consumption level of S. aureus through kimbab were estimated as 30.7% and 3.67 log cfu/g, respectively. Regression sensitivity results showed time-temperature during storage at selling was the most significant factor. These results suggested temperature control under $10^{\circ}C$ was critical control point for kimbab production to prevent growth of S. aureus and showed QMRA was useful for evaluation of factors influencing potential risk and could be applied directly to risk management.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4637-4642
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• 2014

Background: Hypoxia-inducible factor $1{\alpha}$ (HIF-$1{\alpha}$) plays an important role in regulating cell survival and angiogenesis, which are critical for tumor growth and metastasis. Genetic variations of HIF1A have been shown to influence the susceptibility to many kinds of human tumors. Increased expression of HIF-$1{\alpha}$ has also been demonstrated to be involved in tumor progression. However, the prognostic value of single nucleotide polymorphisms (SNPs) inthe HIF1A gene remains to be determined in most cancer types, including colorectal cancer (CRC). In this study, we sought to investigate the predictive role of HIF1A SNPs in prognosis of CRC patients and efficacy of chemotherapy. Materials and Methods: We genotyped two functional SNPs in HIF1A gene using the Sequenom iPLEX genotyping system and then assessed their associations with clinicopathological parameters and clinical outcomes of 697 CRC patients receiving radical surgery using Cox logistic regression model and Kaplan Meier curves. Results: Generally, no significant association was found between these 2 SNPs and clinical outcomes of CRC. In stratified analysis of subgroup without adjuvant chemotherapy, patients carrying CT/TT genotypes of rs2057482 exhibited a borderline significant association with better overall survival when compared with those carrying CC genotype [Hazard ratio (HR), 0.47; 95% confidence interval (95% CI): 0.29-0.76; P < 0.01]. Moreover, significant protective effects on CRC outcomes conferred by adjuvant chemotherapy were exclusively observed in patients carrying CC genotype of rs2057482 and in those carrying AC/CC genotype of rs2301113. Conclusions: Genetic variations in HIF1A gene may modulate the efficacy of adjuvant chemotherapy after surgery in CRC patients.