• Proceedings of the KSR Conference
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• 2005.05a
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• pp.127-131
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• 2005

The running test for the Korean High Speed Train(HSR-350x) was performed at operating maximum sped(350km/h) at December 16th, 2004. HSR-350x had been fabricated in June, 2002 and the on-line test for the performance fo HSR-350x was started with 60km/h at August 19th, 2002. The success of running test at 350km/h is recorded the 4th rank in the world. In this paper, the measured results of the major performance(running behaviour, current collection, stability of rail and bridge) characteristics for HSR-350x are reviewed. All measured values are within the criteria.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.478-479
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• 2009

The HEMU-400X(High-speed Electric Multiple Unit 400km/h eXperimental) project starts in 2007. It is required to analysis and simulate the train performance throughout the project life cycle for a successful completion of the project. This paper is devoted to the development of a train performance analysis model for the high-speed electric multiple unit 400km/h experimental. The model consist of running resistance model, train model, traction model and braking model. So, this paper represents the results of the train performance analysis.

• Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.109-120
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• 2021

Protein hydrolysates and krill meal (KM) are used as protein sources in aquafeeds. The study was conducted to examine the supplemental effects of shrimp protein hydrolysates (SH) or KM in a high-plant-protein diet for red seabream (Pagrus major). A fish meal (FM)-based diet (40%) was considered as the high-FM diet (HFM) and a diet containing 25% FM and soy protein concentrate, in the expense of FM protein from HFM diet, was considered as the low fish meal (LFM) diet. Two other experimental diets (SH and KM) were prepared by including SH and KM into LFM diet at 5% inclusion levels in exchange of 5% FM from the LFM diet. A feeding trial was conducted for fifteen weeks using triplicate group of fish (Initial mean body weight, 8.47 ± 0.05 g) for a diet. Growth performance and feed efficiency of fish were significantly enhanced by HFM, KM and SH supplemented diets over those of fish fed LFM diet. Interestingly, these parameters of fish fed SH diet showed better performance than KM and HFM groups. Liver IGF-I expression of fish fed SH diet was comparable to HFM group and higher than KM and LFM diets. Protein digestibility of SH diet was significantly higher than KM, HFM, and LFM diets. Dry matter digestibility of SH diet was comparable to HFM diet and significantly higher than KM and LFM diets. Nitro blue tetrazolium and superoxide dismutase activities of HFM, SH and KM groups were significantly elevated than the LFM group and SH diet increased catalase and glutathione peroxidase activities of fish compared to KM and LFM groups. Hemoglobin level and hematocrit of fish fed SH and KM diets were significantly higher than LFM group. A diet containing 20% FM with KM is comparable to a HFM diet which contains 40% FM for red seabream. SH can be used to replace FM from red seabream diet down to 20% and fish performance can be improved better than a diet containing 40% FM. Overall, it seems that SH is more effective ingredient in red seabream diet compared to KM.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.668-676
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• 2010

Optimal net residual dispersions (NRDs) of inline dispersion management (DM) for compensating the signal distortion of $24{\times}40$ Gbps WDM channels in optical transmission links, in which optical phase conjugator (OPC) is placed from 250 km to 750 km by spacing 50 km in 1,000 km total transmission length of single mode fiber (SMF), are induced as a function of various ope positions. And, performance improvement of WDM channels in transmission links with the induced optimal NRD is investigated by comparing with that in transmission links with NRD = 0 ps/nm. It is confirmed that optimal NRDs are decided by displacement of OPC from mid-way of total transmission length, i.e. 500 km, and the determinating and applying of optimal NRD in case of ope displacement into transmitters is more stable and effective than that in case of ope displacement into receivers from 500 km. Also, it is shown that eye opening penalties (EOPs) of WDM channels in transmission links with optimal NRD are improved by 1.5 dB to 3 dB, which are related with OPC position, from that obtained in transmission links with fixed NRD of 0 ps/nm.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.11 s.188
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• pp.85-92
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• 2006

For the improvement of a conventional railway speed, tilting train(Tilting Train express) is under the development aiming for a maximum speed 180km/h. Compared to the existing conventional rolling-stock, tilting train could take an advantage of speed improvement about $20{\sim}30%$ on curve sections due to the improvement of cowing performance. However, this speed increasement creates a severe load at wheels, thus it is necessary to study the safety of wheel for tilting train preferentially. On the other hand, it is under consideration that the wheel for conventional railway rolling-stock at speeds of 150km/h will be applied to tilting train at speeds of 180km/h. In this paper, we have studied the strength of wheel structure, the geometrical contact characteristics, and the dynamic performance of wheel to evaluate the safety of wheel for tilting train.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.524-528
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• 2008

The HEMU-400X(High-speed Electric Multiple Unit 400km/h eXperimental) project starts in 2007. It is required to analysis and simulate the train performance throughout the project life cycle for a successful completion of the project. This paper is devoted to the development of a train performance analysis model for the high-speed electric multiple unit 400km/h experimental. The model consist of running resistance model, train model, traction model and braking model. So, this paper represents the results of the train performance analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.167-171
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• 2012

A computational analysis of nozzle flow is conducted to investigate effects of the flight altitude on thrust performance. Reynolds-averaged Navier-Stokes equation with k-${\omega}$ SST(Shear Stress Transport) turbulence model is employed to simulate the nozzle flow in various altitude conditions, where continuum mechanics is to be valid. Thrust performance of the nozzle is exceedingly poor upto 10 km of flight altitude because of the irreversible phenomena such as shock and/or flow separation occurring inside the nozzle, whereas it is restored to the nominal value as the altitude is attained higher than 30 km.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.679-684
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• 2017

Recently, the speed of high-speed railway has been rapidly increase with the development of high-speed train design and operating technology. This causes a lot of complaints related the environmental noise in residential areas near the high-speed railway. In order to operate the high-speed railway in accordance with the design speed, noise reduction technology should be developed to meet the noise characteristics of high-speed railway. And it is important to develop the prediction technology by grasping the noise radiation characteristics. In order to meet these requirements, in recent years, infra-research for 400 km/h high speed railway has been conducted. Reliable noise prediction and noise reduction techniques have been developed through this study. This paper is concerned with wind pressure safety and noise performance evaluation of the newly developed 400 km/h noise reduction device. The wind pressure safety and The noise performance of the developed device was confirmed by this paper.

• Land and Housing Review
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• v.7 no.4
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• pp.307-314
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• 2016

Energy harvesting technique is to utilize energy that is always present but wasted. In this study, we have developed the energy harvester of the hybrid method utilizing both vibration and pressure of the vehicle traveling a road or parking lot. In the previous study, we have developed a prototype energy harvester, improved hybrid energy harvester, and developed a final product that offers improved performance in the hybrid module. The results were published in the previous paper. In this study, we installed the finally developed hybrid module in the actual parking lot. And we measured the power generation performance due to pressure and vibration, and the running speed of the vehicle when the vehicle is traveling. And we compared the results with those obtained in laboratory conditions. In a previous study performed in laboratory conditions the maximum power of the energy block was 1.066W when one single time of vibration, and 1.830W when succession with 5 times. On the other hand, in this study, we obtained the average power output of 0.310W when the vehicle is running at an average 5 km/h, 0.670W when at an average 10 km/h, and 1.250W when at an average 20 km/h, and 2.160W when at an average 5 km/h. That is, the higher the running speed of the vehicle has increased power generation performance. However, when compared to laboratory conditions, the power generation performance of the energy block in driving speed by 20km/h was lower than those in laboratory conditions. In addition, when compared to one time of vibration of laboratory conditions, power generation performance was higher when the running speed 20km/h or more and when five consecutive times in laboratory conditions, it was higher when the running speed 30km/h or more. It could be caused by a difference of load conditions between the laboratory and the actual vehicle. Thus, applying the energy block on the road would be more effective than that on the parking lot.

• Journal of Sasang Constitutional Medicine
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• v.33 no.4
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• pp.1-9
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• 2021

Objectives The purpose of this study was to check whether the classification of the individual's Body Mass Index (BMI) could be predicted by analyzing the voice data constructed at the Korean medicine data center (KDC) using machine learning. Methods In this study, we proposed a convolutional neural network (CNN)-based BMI classification model. The subjects of this study were Korean adults who had completed voice recording and BMI measurement in 2006-2015 among the data established at the Korean Medicine Data Center. Among them, 2,825 data were used for training to build the model, and 566 data were used to assess the performance of the model. As an input feature of CNN, Mel-frequency cepstral coefficient (MFCC) extracted from vowel utterances was used. A model was constructed to predict a total of four groups according to gender and BMI criteria: overweight male, normal male, overweight female, and normal female. Results & Conclusions Performance evaluation was conducted using F1-score and Accuracy. As a result of the prediction for four groups, The average accuracy was 0.6016, and the average F1-score was 0.5922. Although it showed good performance in gender discrimination, it is judged that performance improvement through follow-up studies is necessary for distinguishing BMI within gender. As research on deep learning is active, performance improvement is expected through future research.