• Journal of Hydrogen and New Energy
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• v.20 no.1
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• pp.38-44
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• 2009

Recently, the research focused on fuel cell hybrid vehicles (FCHVs) is becoming an attractive solution due to environmental pollution generated by fossil fuel vehicles. The proper energy control strategy will result in extending the fuel cell lifetime, increasing of energy efficiency and an improvement of vehicle performance. Battery state of charge (SoC) is an important quantity and the estimation of the SoC is also the basis of the energy control strategy for hybrid electric vehicles. Estimating the battery's SoC is complicated by the fact that the SoC depends on many factors such as temperature, battery capacitance and internal resistance. In this paper, battery charging time estimated by SoC is studied by using the speed response and current response. Hybrid system is consist of a fuel cell unit and a battery in series connection. For experiment, speed response of vehicle and current response of battery were determined under different state of charge. As the results, the optimal battery charging time can be estimated. Current response time was faster than RPM response time at low speed and vice versa at high speed.

• Steel and Composite Structures
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• v.7 no.6
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• pp.487-502
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• 2007

In recent decades there has been a trend towards improved mechanical characteristics of materials used in footbridge construction. It has enabled engineers to design lighter, slender and more aesthetic structures. As a result of these construction trends, many footbridges have become more susceptible to vibrations when subjected to dynamic loads. In addition to this, some inherit modelling uncertainties related to a lack of information on the as-built structure, such as boundary conditions, material properties, and the effects of non-structural elements make difficult to evaluate modal properties of footbridges, analytically. For these purposes, modal testing of footbridges is used to rectify these problems after construction. This paper describes an arch type steel footbridge, its analytical modelling, modal testing and finite element model calibration. A modern steel footbridge which has arch type structural system and located on the Karadeniz coast road in Trabzon, Turkey is selected as an application. An analytical modal analysis is performed on the developed 3D finite element model of footbridge to provide the analytical frequencies and mode shapes. The field ambient vibration tests on the footbridge deck under natural excitation such as human walking and traffic loads are conducted. The output-only modal parameter identification is carried out by using the peak picking of the average normalized power spectral densities in the frequency domain and stochastic subspace identification in the time domain, and dynamic characteristics such as natural frequencies mode shapes and damping ratios are determined. The finite element model of footbridge is calibrated to minimize the differences between analytically and experimentally estimated modal properties by changing some uncertain modelling parameters such as material properties. At the end of the study, maximum differences in the natural frequencies are reduced from 22% to only %5 and good agreement is found between analytical and experimental dynamic characteristics such as natural frequencies, mode shapes by model calibration.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.63-67
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• 2015

White light-emitting diode (WLED) is growing interest in using both illumination and communications. This paper reports visible light communication (VLC) composed of a super bright white light-emitting diode, low cost commercial photo-diode and a Fresnel lens. LED driver is consisted of the power MOSFET and MOSFET driver that switches the LED on and off. The modulation bandwidth of the LED used was determined to be 8 MHz. However, it was possible to communicate up to 1 Mbps under illumination of 500 lx because of the weak signal power and a low spectral sensitivity of the SHF213 as a PIN photodiode. In order to enhance the system bandwidth, the LED light was focused on the PIN photodiode by use of the Fresnel lens. As a result of that, visible light link was operated up to modulation bandwidth of the LED. The signal to noise ratio can be improved by 40 dB using an optical concentration at the receiver.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5091-5096
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• 2012

Background: There is a large amount of evidence that the ABO blood group system may play a role in disease etiology. A relationship between ABO and Rhesus blood groups and cancer risk has been demonstrated in a number of studies. However, in relation to gynecological malignancies, these findings are inconsistent and contradictory. Aim: To perform a case-control study for analysis of the distribution of ABO and Rh blood antigens among women from South-East Siberia who suffered from ovarian, endometrial and cervical cancer, and to assess the potential role of these antigens in carcinogenesis. Design, Subjects and Methods: A total of 1,163 cases with ovarian cancer (n=551), endometrial cancer (n=440) and cervical cancer (n=172) were involved in the study. The control group was formed from 22,581 female blood donors. Blood groups were determined through patients medical records and blood donor records. Odds ratios (OR) with 95% confidence intervals (CI) were calculated. The blood group O was defined as the referent group, as it has the greatest frequency in the populations of Southern Siberia. P values less than 0.05 were regarded as statistically significant. Results: We found that carriage of non-O blood types increased the risk of ovarian cancer by 40-60%, and the magnitude of this relationship was strongest in women with the AB (IV) blood group. Carriage of the A (II) blood group strongly correlated with an increased risk of ovarian cancer in premenopausal, but not in postmenopausal women. No statistically significant correlations were obtained for endometrial cancer and cervical cancer. Additionally, we did not observe a relationship between Rhesus factor and cancer risk. Conclusion: We suggest that carriage of non-O blood groups may elevate risk of ovarian cancer and can play a role in its development.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.689-699
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• 2020

The National Science and Technology Information Center (NDSL) database, which provides academic papers at home and abroad, collects, builds, and manages data collected from various sources. In this study, we analyzed the DB paper schema and DB metadata that are currently constructed and managed to derive an integrated DB schema that can manage the high-value-added papers and manage them efficiently by analyzing distributed DB papers. Also, the final academic information data items were determined through comparison and analysis using the Web of Science and SCOPUS schemas that are currently purchased and possessed. The academic information data items constructed and serviced through this study were summarized into seven papers, authors, abstracts, institutions, themes, journals, and references, and defined as core contents under construction. The integrated DB schema was created through this study, and the results of this study will be used as a basis for constructing the integrated DB collection of high quality academic papers and designing the integrated system.

• Preventive Nutrition and Food Science
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• v.20 no.2
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• pp.119-125
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• 2015

The biologically active compounds raphasatin and sulforaphene are formed during the hydrolysis of radishes by an endogenous myrosinase. Raphasatin is very unstable, and it is generated and simultaneously degraded to less active compounds during hydrolysis in aqueous media. This study determined the hydrolysis conditions to maximize the formation of raphasatin and sulforaphene by an endogenous myrosinase and minimize their degradation during the hydrolysis of radish roots. The reaction parameters, such as the reaction medium, reaction time, type of mixing, and reaction temperature were optimized. A stability test for raphasatin and sulforaphene was also performed during storage of the hydrolyzed products at $25^{\circ}C$ for 10 days. The formation and breakdown of raphasatin and sulforaphene in radish roots by endogenous enzymolysis was strongly influenced by the reaction medium, reaction time, and type of mixing. The production and stabilization of raphasatin in radishes was efficient in water and dichloromethane with shaking for 15 min at $25^{\circ}C$. For sulforaphene, the favorable condition was water as the reaction medium without shaking for 10 min at $25^{\circ}C$. The maximum yields of raphasatin and sulforaphene were achieved in a concurrent hydrolysis reaction without shaking in water for 10 min and then with shaking in dichloromethane for 15 min at $25^{\circ}C$. Under these conditions, the yields of raphasatin and sulforaphene were maximized at 12.89 and $1.93{\mu}mol/g$ of dry radish, respectively. The stabilities of raphasatin and sulforaphene in the hydrolyzed products were 56.4% and 86.5% after 10 days of storage in water and dichloromethane at $25^{\circ}C$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.691-697
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• 2016

Remanufacturing refers to restoring a used product to an acceptable condition for resale in the market of remanufactured items. In this paper, we deal with the acquisition price and remanufacturing decision for remanufacturing systems in the case where the demand for the remanufactured product in a single period is known and the return quantity of the used product is determined by its acquisition price. The quality of the acquired used product is categorized into two classes, high and low, through inspection and different qualities incur different remanufacturing costs. The probability that the acquired used product is categorized as high class can be a constant or random variable. We derive the expected total cost functions, obtain the optimal solutions, and interpret the managerial meaning of the optimal solution for each case. The sensitivity of the optimal solution with respect to the variation of the inspection cost and uncertainty of the quality of the used product is investigated through numerical examples.

• Journal of the Korean Society for information Management
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• v.25 no.3
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• pp.143-158
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• 2008

This study was conducted under the premise of providing the model for the construction of the library and the digital library in PUST, the joint construction from South and North Korea. First, we determined the problems in the construction of digital libraries as well as possible issues that may rise from the construction of the digital library in PUST. The results of the research showed that there were imminent problems from the operation of a digital library with the inadequate progress in the Held of copyright. In addition, the difference in the language system and the knowledge foundations of the two countries will produce problems in the homepage access, database construction, and information retrieval. In order to overcome these predictable problems, this research proposes the following: (1) parallel operation of both digital and high-drive libraries; (2) duplexing the homepage through the application of unicode concerning the digital library; (3) development and application of converted letter codes through the establishment of NCHAR data type; and (4) construction of an authority database.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.516-520
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• 2009

The purpose of this study is to determine optimal filtering condition and threshold for the detection of gait-cycles for various walkway slopes as well as gait velocities. Ten young healthy subjects with accelerometer system on thigh and ankle walked on a treadmill at 9 conditions (three speeds and three slopes) for 5 minutes. Two direction signals, i.e. anterior-posterior (AP) and superior-inferior (SI) directions, of each sensor (four sensor orientations) were used to detect specific events of gait cycle. Variation of the threshold (from -1G to 1G) and lowpass cutoff frequency (fc) were applied to the event detection and their performance was evaluated according to the error index (EI), which was defined as the combination of the accuracy and false positive rate. Optimal fc and threshold were determined for each slope in terms of the EI. The optimal fc, threshold and their corresponding EI depended much on the walkway slope so that their coefficients of variation (CV) ranged 19~120%. When all data for 3 slopes were used in the identification of optimal conditions for each sensor, the best error indices for all sensor orientations were comparable ranging 1.43~1.76%, but the optimal fc and threshold depended much on the sensor position. The result indicates that the gait-cycle detection robust to walkway slope is possible by threshold method with well-defined filtering condition and threshold.

• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.228-233
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• 2015

Purpose: Gait is the most basic element when evaluating the quality of life with activities of daily living under ordinary life circumstances. Symmetrical use of the lower extremities requires complicated coordination of all limbs. Thus, this study examined asymmetry of muscle activity quadriceps femoris and tibialis anterior as a baseline for training during over-ground walking and stair walking of stroke patients. Methods: Subjects were 14 stroke patients included as one experimental group. Gait speed used in this study was determined by the subject. Low extremity paretic and non-paretic EMG was compared using the surface EMG system. Results: The low extremity EMG difference was statistically significant during over-ground walking and stair walking (p<0.05). The result of low extremity EMG substituted symmetry ratio formula was compared to EMG symmetry ratio in both legs during over-ground walking and stair walking. The average symmetry ratio of quadriceps femoris during over-ground walking was 0.65, and average symmetry ratio of quadriceps femoris during stair walking was 0.47, with significant difference (p<0.05). Conclusion: EMG data was higher in stair walking than over-ground walking. However, in the comparison of symmetry ratio, asymmetric EMG of quadriceps femoris was significantly increased during stair walking. These findings suggested that application of stair walking for strengthening of both legs can be positive, but the key factor is maintaining asymmetrical posture of both legs. Therefore, physical therapists should make an effort to reduce asymmetry of quadriceps femoris power during stair walking by stroke patients.