• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1085-1090
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• 2011

To assure the safety of rolling stock, it is important to perform the fatigue analysis of reduction gear unit in rolling stock considering a variation of velocity and traction motor capability. This paper presents fatigue analysis of the damage of reduction gear unit of railway vehicle under variable amplitude loading(VAL) based on quasi-static fatigue analysis using finite element model and linear Miner's rule. The VAL for the simulation was constructed from the tractive effort curve and train run curves of railway vehicle under commercial operation condition using MSC.ADAMS dynamic analysis. The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the middle gear based on strain-life based approach. The results showed that the frequent high starting torque due to a quick start as well as increasing numbers of stops at station would decrease the fatigue life of reduction gear unit.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.498-509
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• 2018

involves philosophical perspectives that are different from other SF movies. This perspective was derived from that of Zecharia Sitchin, in which he tells the history of the earth and mankind from a very unique perspective. He claimed that the intelligent beings (according to Sitchen, we called them the gods) on this planet created mankind and brought them ancient civilizations. The purpose of this study is to analyze under the determination that a comparative analysis can be made between SF movies and an art genre, in the outlook that Sitchin's perspectives are under extraordinary attention of religious and academic circles and are assisting in solving many mysteries on earth with currently excavated archaeological evidences, to identify the factors of consensus between the message Sitchin wanted to convey and SF movies and find the historical perspectives of Sitchin in the cross-section between Sitchin and the narratives in .

• Radiation Oncology Journal
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• v.37 no.2
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• pp.117-126
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• 2019

Purpose: The purpose of this study was to characterize and evaluate the clinical significance of volume changes of soft tissue sarcomas during radiation therapy (RT), prior to definitive surgical resection. Materials and Methods: Patients with extremity or pelvis soft tissue sarcomas treated at our institution from 2013 to 2016 with RT prior to resection were identified retrospectively. Tumor volumes were measured using cone-beam computed tomography obtained daily during RT. Linear regression evaluated the linearity of volume changes. Kruskal-Wallis tests, Mann-Whitney U tests, and linear regression evaluated predictors of volume change. Logistic and Cox regression evaluated volume change as a predictor of resection margin status, histologic treatment response, and tumor recurrence. Results: Thirty-three patients were evaluated. Twenty-nine tumors were high grade. Prior to RT, median tumor volume was 189 mL (range, 7.2 to 4,885 mL). Sixteen tumors demonstrated significant linear volume changes during RT. Of these, 5 tumors increased and 11 decreased in volume. Myxoid liposarcoma (n = 5, 15%) predicted decreasing tumor volume (p = 0.0002). Sequential chemoradiation (n = 4, 12%) predicted increasing tumor volume (p = 0.008) and corresponded to longer times from diagnosis to RT (p = 0.01). Resection margins were positive in three cases. Five patients experienced local recurrence, and 7 experienced distant recurrence, at median 8.9 and 6.9 months post-resection, respectively. Volume changes did not predict resection margin status, local recurrence, or distant recurrence. Conclusion: Volume changes of pelvis and extremity soft tissue sarcomas followed linear trends during RT. Volume changes reflected histologic subtype and treatment characteristics but did not predict margin status or recurrence after resection.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.379-384
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• 2014

This article describes the dynamic behaviors of a rubber tired gantry crane(RTGC) under typical load conditions which are used in the design of gantry cranes. In order to investigate the dynamic characteristics of an RTGC, we developed a finite element crane model for its huge structure. The finite element model was validated with the modal test results, e.g., natural frequencies and normal modes. And other components of RTGC were converted into detailed 3D CAD models and finally transformed to rigid body models in a dynamic simulation program ADAMS. The load conditions considered in this paper were a normal operating condition(OP1) and container hanging condition with no external loads. As a result, we could find there was large influence of crane's vibration owing to its structural stiffness and deformation. And the vibration of crane could made the movements of RTGC, which occurs crash or malfunction of crane works.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.18 no.3
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• pp.168-174
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• 2015

Purpose: Recent studies have suggested that decreased serum potassium level may contribute to various metabolic disorders in adult patients including nonalcoholic fatty liver disease (NAFLD). We aimed to study the correlation between serum potassium levels and the histologic severity of NAFLD in children. Methods: Pediatric patients with biopsy-proven NAFLD were included in this study. Demographic, clinical, and histopathological data were obtained. Multivariable logistic regression analysis was used to assess whether potassium levels are associated with the presence of nonalcoholic steatohepatitis (NASH) or fibrosis after adjusting for possible confounders. A p-value <0.05 was considered statistically significant. Results: Among 125 biopsies, 49.6% (62) had evidence of NASH while 66.4% (83) had some degree of fibrosis (stage 1-3). Mean serum potassium was significantly lower in NASH group as compared to non-NASH group ($4.4{\pm}0.42mmoL/L$ vs. $4.8{\pm}0.21$, p<0.001). Higher potassium level had negative correlation with presence of steatosis, ballooning, lobular inflammation, fibrosis and NAFLD activity score (p<0.05). On multivariable analysis and after adjusting for the metabolic syndrome and insulin resistance, higher potassium level was significantly associated with lower likelihood of having a histological diagnosis of NASH on biopsy (odds ratio [OR], 0.12; 95% confidence interval [95% CI], 0.05-0.28; p<0.001). Similarly, the likelihood of having fibrosis decreases by 76% for every 0.5 mmoL/L increase in potassium (OR, 0.24; 95% CI, 0.11-0.54; p<0.001). Conclusion: Our study shows an inverse relationship between serum potassium levels and the presence of aggressive disease (NASH and fibrosis) in children with NAFLD.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.371-383
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• 2014

The nematode Caenorhabditis elegans (C. elegans) offers a unique opportunity for biological and basic medical researches due to its genetic tractability and well-defined developmental lineage. It also provides an exceptional model for genetic, molecular, and cellular analysis of human disease-related genes. Recently, C. elegans has been used as an ideal model for the identification and functional analysis of drugs (or small-molecules) in vivo. In this review, we describe conserved oncogenic signaling pathways (Wnt, Notch, and Ras) and their potential roles in the development of cancer stem cells. During C. elegans germline development, these signaling pathways regulate multiple cellular processes such as germline stem cell niche specification, germline stem cell maintenance, and germ cell fate specification. Therefore, the aberrant regulations of these signaling pathways can cause either loss of germline stem cells or overproliferation of a specific cell type, resulting in sterility. This sterility phenotype allows us to identify drugs that can modulate the oncogenic signaling pathways directly or indirectly through a high-throughput screening. Current in vivo or in vitro screening methods are largely focused on the specific core signaling components. However, this phenotype-based screening will identify drugs that possibly target upstream or downstream of core signaling pathways as well as exclude toxic effects. Although phenotype-based drug screening is ideal, the identification of drug targets is a major challenge. We here introduce a new technique, called Drug Affinity Responsive Target Stability (DARTS). This innovative method is able to identify the target of the identified drug. Importantly, signaling pathways and their regulators in C. elegans are highly conserved in most vertebrates, including humans. Therefore, C. elegans will provide a great opportunity to identify therapeutic drugs and their targets, as well as to understand mechanisms underlying the formation of cancer.

• Advances in aircraft and spacecraft science
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• v.6 no.6
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• pp.529-550
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• 2019

The effect of multiple process parameters on a set of continuous response variables is, especially in experimental designs, difficult and intricate to determine. Due to the complexity in aeroacoustic and vibroacoustic studies, the often-performed simple one-factor-at-a-time method turns out to be the least effective approach. In contrast, the statistical Design of Experiments is a technique used with the objective to maximize the obtained information while keeping the experimental effort at a minimum. The presented work aims at giving insights on Design of Experiments applied to aeroacoustic and vibroacoustic problems while comparing different experimental designs and approximation models. For this purpose, an experimental rig of a ducted low-pressure fan is developed that allows gathering data of both, aerodynamic and aeroacoustic nature while analysing three independent process parameters. The experimental designs used to sample the design space are a Central Composite design and a Box-Behnken design, both used to model a response surface regression, and Latin Hypercube sampling to model an Artificial Neural network. The results indicate that Latin Hypercube sampling extracts information that is more diverse and, in combination with an Artificial Neural network, outperforms the quadratic response surface regressions. It is shown that the Latin Hypercube sampling, initially developed for computer-aided experiments, can also be used as an experimental design. To further increase the benefit of the presented approach, spectral information of every experimental test point is extracted and Artificial Neural networks are chosen for modelling the spectral information since they show to be the most universal approximators.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4921-4926
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• 2015

Background: Breast cancer is the most common cancer type among women with increasing incidence rates, improved prognosis and survival. According to the localization of the tumor, breast cancer is designated as unilateral (UBC) or bilateral (BBC). BBC can be classified as synchronous (SBBC) or metachronous (MBBC) based on the time interval between the diagnosis of the first and the secondary tumors. According to the guideline of WHO 2012, BBC is generally defined as SBBC when contralateral breast carcinoma is diagnosed within 3 months. The aim of this study was to compare the characteristics and patterns of metastasis of BBC patients with UBC. Materials and Methods: A cohort of 768 patients with breast cancer treated at the Turkish Ministry of Health-Izmir Bozyaka Research and Training Hospital between 1976 and 2012 were studied. Survival analysis was performed comparing UBC and BBC patients. In addition, evaluations were performed in patients with SBBC and MBBC sub-groups. We used a 3-months interval to distinguish metachronous from synchronous. Results: When clinical and histopathological parameters were statistically evaluated, ER status, event-free and overall survival were found to be significant between UBC and BBC patients. In comparison of SBBC and MBBC patients, age, histological type of tumor, event-free and overall survival were found to be significant. Conclusions: BBC cases were found to show worse prognosis than UBC cases. Among BBC, SBBC had the worst prognosis based on overall survival rates.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.12
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• pp.1579-1584
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• 2011

This paper discusses an energy system that can convert wave energy into electrical energy. This wave energy generation system is movable and has 12 arms and one generator. A multibody dynamic model for this system is established by using kinematic constraints. A gear mechanism, several kinematic constraints, and force elements are included in the model. Wave forces are obtained numerically from the time domain formulation based on the Morison equation. The MSC/ADAMS program is employed to carry out dynamic analysis of the wave energy generation system. The dynamic behavior responses of this system are analyzed for design verification. According to the results of the dynamic analysis, the yaw motion is relatively stable and kinetic energy sufficient to generate electrical energy is obtained when the wave height exceeds 1m.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.520-525
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• 2020

In this study, we developed a machine learning-based model for predicting the production stage temperature of distillation process. It is necessary to predict an accurate temperature for control because the control of the distillation process is done through the production stage temperature. The temperature in distillation process has a nonlinear complex relationship with other variables and time series data, so we used the recurrent neural network algorithms to predict temperature. In the model development process, by adjusting three recurrent neural network based algorithms, and batch size, we selected the most appropriate model for predicting the production stage temperature. LSTM₁₂₈ was selected as the most appropriate model for predicting the production stage temperature. The prediction performance of selected model for the actual temperature is RMSE of 0.0791 and R² of 0.924.