• Transactions of the Korean hydrogen and new energy society
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• v.31 no.5
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• pp.436-443
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• 2020

The performance prediction model of a solid oxide fuel cell stack has been developed using deep neural network technique, one of the machine learning methods. The machine learning has been received much interest in various fields, including energy system mo- deling. Using machine learning technique can save time and cost requried in developing an energy system model being compared to the conventional method, that is a combination of a mathematical modeling and an experimental validation. Results reveal that the mean average percent error, root mean square error, and coefficient of determination (R2) range 1.7515, 0.1342, 0.8597, repectively, in maximum. To improve the predictability of the model, the pre-processing is effective and interpolative machine learning and application is more accurate than the extrapolative cases.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.190-193
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• 2001

In order to verify the efficiency or availability and stability of photovoltaic(PV) generation systems, huge system apparatuses are needed, in general, in which an actual size of solar panel, a type of converter system and some amount of load facilities should be installed in a particular location. It is also hardly possible to compare a Maximum Power Point Tracking (MPPT) control scheme with others under the same weather and load conditions in an actual PV generation system. The only and a possible way to bring above-mentioned problem to be solved is to realize a transient simulation scheme for PV generation systems using real weather conditions such as insolation and surface temperature of solar cell. The authors, in this paper, introduces a novel simulation method, which is based on a real-time digital simulator (RTDS), for PV generation systems under the real weather conditions. Firstly, VI characteristic equation of a solar cell is developed as an empirical formula and reconstructed in the RTDS system, then the real data of weather conditions are interfaced to the analogue inputs of the RTDS. The outcomes of the simulation demonstrate the effectiveness of the proposed simulation scheme in this paper. The results shows that the cost effective verifying for the efficiency or availability and stability of PV generation systems and the comparison research of various control schemes like MPPT under the same real weather conditions are possible.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.1
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• pp.17-25
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• 2016

Purpose: This study was aimed to determine the effects of thoracic spine thrust manipulation on muscle activities of the scapular upward rotators and middle deltoid, active range of motion (AROM), shoulder pain, and rounded shoulder posture in young adults with rounded shoulder. Methods: The subjects were 30 young adults (14 males, 16 females) with rounded shoulder. Thirty subjects were randomly assigned to an experimental (manipulation) and control (placebo) groups of fifteen subjects respectively. The manipulation group received the manipulation (high velocity, low amplitude), which was performed by a physical therapist with the subject in the supine position and with the arms crossed over the chest and hands passed over the shoulders. For the sham group, the same procedure was performed, with the exception that the high-velocity thrust was not applied. Measurements were taken before and after the intervention. Muscle activity of upper and lower trapezius, serratus anterior, middle deltoid was measured using surface electromyography. Visual analog scale (VAS) was used for shoulder pain. Goniometry was used for shoulder abduction active range of motion (AROM). Straight edge was used for supine rounded shoulder posture (RSP) distance. Results: The muscle activity of the upper trapezius, lower trapezius and middle deltoid muscle increased significantly after the intervention (p<.05). However, no significant difference was observed in serratus anterior muscle (p>.05). The VAS was significantly decreased and AROM significantly increased after the intervention (p<.05). The distance of RSP were not significant (p>.05). The control group showed no differences before and after the intervention (p>.05). Conclusion: The results of this study suggest that thoracic spine thrust manipulation can be an effective component of treatment plan to improve pain and function.

• The Journal of Bigdata
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• v.4 no.2
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• pp.207-220
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• 2019

Recent developments in information and communication technology has enabled the deployment of sensor based data to provide real-time services. In Korea, The Korea Transportation Safety Authority is collecting driving information of all commercial vehicles through a fitted digital tachograph (DTG). This information gathered using DTG can be utilized in various ways in the field of transportation. Notably in autonomous driving, the real-time analysis of this information can be used to prevent or respond to dangerous driving behavior. However, there is a limit to processing a large amount of data at a level suitable for real-time services using a traditional database system. In particular, due to a such technical problem, the processing of large quantity of traffic big data for real-time commercial vehicle operation information analysis has never been attempted in Korea. In order to solve this problem, this study optimized the new database server system and confirmed that a real-time service is possible. It is expected that the constructed database system will be used to secure base data needed to establish digital twin and autonomous driving environments.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.99-107
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• 2009

Since a long work piece influences the natural frequency of the entire system with a miniature high speed spindle, a bar-feeder is used for a long work piece to improve the vibration characteristics of a spindle system. Therefore, it is very important to design optimally support positions between a bar-feeder and a long work piece for a miniature high speed spindle system. The goal of the current paper is to present an optimization method for the design of support positions between a bar-feeder and a long work piece. This optimization method is effectively composed of the method of design of experiment (DOE), the artificial neural network (ANN) and the genetic algorithm (GA). First, finite element models which include a high speed spindle, a long work piece and the support conditions of a bar-feeder were generated from the orthogonal array of the DOE method, and then the results of natural vibration analysis using FEM were provided for the learning inputs of the neural network. Finally, the design of bar-feeder support positions was optimized by the genetic algorithm method using the neural network approximations.

• Journal of Life Science
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• v.12 no.5
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• pp.577-583
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• 2002

The growth kinetics and the production of $\beta$-glucuronidase from transgenic tobacco's suspension culture was investigated in the flask culture and a 2.5 L bubble column reactor. The growth of bubble column reactor was similar to that of flask culture. However, in the bubble column reactor, the production of $\beta$ -glucuronidase reached 2850 U/mg (85-fold higher than that of flask culture). In both case, the production level of $\beta$ -glucuronidase was fluctuated, which was resulted from periodical degradation of the protein. Sucrose is important component in plant culture medium. Twice addition of sucrose in bubble column reactor could not improve cell growth, since other components in a medium were already depleted. However, the addition of sugar decreased cell size, which facilitated the operation of bioreactor. The production of $\beta$ -glucuronidase was continuously increased, however final concentration of $\beta$ -glucuronidase was similar to that without sucrose addition.

• YAKHAK HOEJI
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• v.51 no.5
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• pp.296-300
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• 2007

The purpose of this study was to investigate the preventive effects of Lycii fructus Extract (LFE) against the acute hepatotoxicity-inducing lipopolysaccharide (LPS) in the liver. LFE of 100 mg/kg concentration was intraperitoneally administered into rats at dose of 1.5 ml/kg for 20 days. On the day 21, 1.5 ml/kg of LPS dissolved in saline was injected 4 hours before anesthetization. We examined the levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), lactate dehydrogenase (LDH) in serum of rats, superoxide dismutase (SOD) in mitochondrial fraction, and malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPx) in liver homogenate. LPS-treatment markedly increased the levels of GOT, GPT, LDH and MDA, and significantly decreased those of SOD, CAT and GPx. But LFE-pretreatment decreased the levels of GOT, GPT, LDH and MDA, by 17.7%, 27.5%, 40.7% and 56.9%, respectively and increased those of SOD, CAT and GPx, by 90.5%, 78.9% and 83.8%, respectively. These results showed that the LFE had the preventive effects against the acute hepatotoxicity-inducing LPS in the liver.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.427-432
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• 2006

Purpose: Noninflammatory synovial fibrosis has been noted for main causal factor of carpal tunnel syndrome (CTS). Recently, there are some reports that heparin have not only anti-coagulative effect but also anti-inflammatory and anti-fibrotic potential and have an effect on interstitial pulmonary fiborosis. Authors examined whether heparin affects pathogenesis of CTS. Methods: First, heparin was administered to fibroblast that was cultured from patient's transverse carpal ligament. Secondly, we evaluated the expression from genes of type I, III collagen, TGF ${\beta}$ isoforms and MMP. Fibroblasts were isolated and cultured from transverse carpal ligaments of 5 patients with CTS. Heparin (0, 1, 10,$100{\mu}g/ml$) was administered to cultured fibroblast and reverse transcription PCR for mRNA expression of type I, III collagen, TGF-${\beta}$ isoforms and MMP was done. Results: Heparin suppressed gene expression of type I, III collagen and TGF-${\beta}1$, ${\beta}3$ but promoted gene expression of TGF-${\beta}2$ and MMP-2. Conclusion: Heparin directly suppress gene expression of type I, III collagen. But, It is undetermined that heparin can present it's effect mediated by TGF ${\beta}$ isoforms or MMP.

• Journal of Korean Society of Steel Construction
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• v.26 no.2
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• pp.133-142
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• 2014

Double split tee connection is a full strength-partial restrained connection that suitable for ordinary moment frame and special moment frame which demonstrates behavior characteristics depending on the stiffness ratio of columns and beams, changes in the geometric shape of the T-stub, number of fasteners and effect of panel zone. For the double split tee connection to ensure structurally safe behavior, it needs to exhibit sufficient strength, stiffness and ductile capacity. This study sought to investigate the effects of the moment-rotation angle relationship of the double split tee connection and to evaluate the initial rotational stiffness of the double split tee connection depending on changes in the geometric shape of the T-stub. To this end, two different double split tee connection specimens are experimented which designed to change geometric parameter values (${\alpha}^{\prime}$) of the T-stub, and a three-dimensional finite element analysis was performed.

• The Journal of the Korean bone and joint tumor society
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• v.5 no.4
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• pp.221-228
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• 1999

The purpose of this study was to verify the importance of apoptosis in genesis of osteosarcoma and whether apoptosis may play an important role as a predictive factor for the response to chemotherapy. Of the patients who were diagnosed osteosarcoma between January 1995 and June 1999, ten patients were selected. All specimens were obtained before and after preoperative chemotherapy and examined for the occurrence of apoptosis. Apoptosis was investigated by in situ end-labeling technique on paraffin-embedded sections and apoptotic indices were calculated before and after chemotherapy. The ages of ten patients ranged from 15 to 59 with equal sex ratio. All patients completed the planned pre-operative chemotherapy. Apoptosis occurs in osteosarcoma and apoptotic indices are increased after chemotherapy. Mean apoptotic index (AI) before and after chemotherapy were 17.2 (range 6-28.9) and 26.3 (9.6-46.2), respectively. Apoptotic cells were usually present around the necrotic area. The AI was increased as the progression of stage and in responder group more than in non-responder. Apoptosis is induced by pre-operative chemotherapy and the response is variable. Changes in AI levels before and after chemotherapy may possibly predict an individual patient's overall response.