• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.121-127
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• 2023

A 500 km/h linear motor high speed terrestrial transportation service is planned to launch 2027 in Japan. In order to support 5G service in the train, the Sub-carrier spacing frequency of 30 kHz is planned to be used instead of common 15 kHz sub-carrier spacing to mitigate Doppler effect in such high-speed transportation. In addition, to increase the cell size of 5G mobile system, plural Base Station antenna will transmit the identical Down Link (DL) signal to form the expanded cell size along the train rail. In this situation, forward and backward antenna signals will be Doppler shifted by reverse direction respectively and the receiver in the train might suffer to estimate accurate Channel Transfer Function (CTF) for its demodulation. In this paper, Delay and Doppler Profiler (DDP) based Channel Estimator is proposed and it is successfully implemented in signal processing simulation system. Then the simulated performances are compared with the conventional Time domain linear interpolated estimator. According to the simulation results, QPSK modulation can be used even under severe channel condition such as 500 km/h, 2 path reverse Doppler Shift condition, although QPSK modulation can be used less than 200 km/h with conventional Channel estimator.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.7 no.1
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• pp.26-38
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• 2000

The purpose of this study was to estimate home care nursing cost for the patient with Cerebrovascular Disease based on a bundle of home care nursing services This study was conducted through four steps. The first step was to investigate home care nursing activities that were offered to the patient with Cerebrovascular Disease(CD) by home care nurse. The second step was to investigate the time spent on home care nursing service and to calculate labor and manufacturing cost. The third step was to calculate home care nursing cost per minute. And at the fourth step, home care nursing cost for a patient with Cerebrovascular Disease based on a bundle of home care nursing service was calculated. The results of the study were as follows: 1) The number of direct home care nursing activities for the patient with CD was 108, and the time of each activity was spent from 1 to 10 minutes. 2) Average time per visit was 51 minute, and the firs visit time were spent 1.6 times higher than 2nd visit time. 3) Nursing cost per minute(cost per visit ${\\}\;22,565\;\div\;$ average time per visit 51 minutes) was ${\\}\;442$. The cost per visit was calculated on Basic visiting cost(nurse's labor cost ${\\}\;15,760$ + management cost ${\\}\;6,805$) divided by average time per visit(51 minutes). 4) Home care nursing cost to the patient with CD based on bundle of home care nursing service was consisted of basic home care nursing cost, the cost of a bundle of service practiced on visit. and transportation fee. Basic home nursing cost(the time spent on basic home nursing service 20 minutes ${\times}$ nursing cost per minute ${\\}\;442$) was ${\\}\;8,840$. The cost of the bundle of home care nursing services to the patient with CD was calculated as self care ${\\}\;2.898$, Tracheostomy care ${\\}\;10,166$, immobility care ${\\}\;6,188$, sore care ${\\}\;6,188$. Foley care ${\\}\;6,630$, and Levin tube or Gastrostomy care ${\\}\;7.514$. Transportation fee which was composed of the labor cost for transportation(${\\}\;5,122$) and the car management cost(${\\}\;3.876$) was ${\\}\;8,998$. Home care nursing cost to the patient with CD based on bundle of home care nursing services consisted of basic home care nursing cost, the cost of a bundle of service practiced on visit, and transportation fee. It will contribute to improve quality of home care service, because of giving appreciate incentives to home care nurses. And it will be more efficient than current cost of hospital based home care. But it need to management than calculation of the current fee-for-services of home care.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.413-414
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• 2002

An automotive wheel bearing is one of the most important components to guarantee the service life of a passenger car. The endurance life of a bearing is affected by many parameters such as material properties, heat treatment, lubrication conditions temperature loading conditions, bearing geometry, internal clearance and so on. In this paper, we calculate the endurance life of wheel bearing units and analyze the sensitivity of bearing geometric parameters on the life by using Taguchi method.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.594-600
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• 2011

"The guidelines on the management of indoor air quality of public transportation" was enacted in December 2006 due to the fact that the interest and demand of improving the air quality for citizen using public transportation have been increased. Thus this research has considered what has influenced on the passenger cabin HVAC as well as the improvement of customer service as we proceed the study for better indoor air quality inside of the train by developing the module of cleaning air system for pollutants of a car air.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1227-1234
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• 2011

Korea is a mountainous country, with as much as 70% of the area is covered by hills and mountains. This geography places constraints on the minimum radius of curvature for the rail network. It was expected that the speed of trains could be enhanced on the existing railway network without a huge investment in infrastructure by using tilting trains. The development of tilting trains in Korea started in 2001 as research & development project. A 6-car prototype test tilting train, called the Tilting Train eXpress (TTX), was built in December 2006 and experimental trials began in 2007. TTX has distributed power, is designed to run at 200 km/h, and has a planned service speed of 180 km/h. In this paper, we first describe the performance of tilting train, and then present the estimated running times, and the time saving compared with today's conventional trains and non-tilting trains, based on the Jungang line. So the time saving could be separated into two effects by higher track top-speed and tilting devices.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.307-309
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• 2006

There are operated the six thousand train in the interior of a country. 95% of them are possible usage of resuscitation. Especially, Among them VVVF-Inverter vehicle has a merit of the highest recycle rate. but we don't use a apt recycled energy. Although the existing recycle energy used inverter method supply with electric power, it is decided in accordance with the state of sources. So efficiency of recycled electric power is of poor quality and catenary-voltage-fluctuation be generate because of recycled electric power. and it is able to affect system of safety train service. We'll research the method of supply according to wire condition after storing recycle energy made during train's stopping relation to Advanced EMU Research. Those methods are divided SMES, Fly-Wheel and Supercapacitor, and Considering the both economical efficiency and system application, we'll develop recycle energy storage system suitable our country condition.

• Proceedings of the KSPS conference
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• 2002.11a
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• pp.191-194
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• 2002

Lip-reading technology that is studied them is used to compensate speech recognition degradation in noise environment in bi-modal's form. The most important thing is that search for correct lips area in this lip-reading. But, it is hard to forecast stable performance in dynamic environment. Used RASTA filter that show good performance to remove noise in the speech to compensate. This filter shows that improve performance of using time domain of digital filter. To this experiment observes performance of speech recognition only using image information, service chooses possible 22 words and did recognition experiment in car. We used hidden Markov model by speech recognition algorithm to compare this words' recognition performance.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.235-241
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• 2006

The demand of 3D terrain mapping techniques is increasing in many application fields such as CNS(Car Navigation System), web service system, DMB(Digital Multimedia Broadcasting) systems and etc To construct a 3D terrain map, it is a pre-requite step that register data collected from different surveying sources. This Paper Present the methodology to register airborne photo, LIDAR data, and digital map, which are major data sources to create a 3D terrain mao. For this purpose, we developed the generally applicable algorithm that uses linear features to register airborne photos and digital maps to LIDAR data. The algorithm explicitly formulates step-by-step methodologies to establish observation equations for transformation. The results clearly demonstrate the proposed algorithm is appropriate to register these data sources.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.162-167
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• 2002

An automotive wheel bearing is one of the most important components to guarantee the service life of a passenger car. The endurance life of a bearing is affected by many parameters such as material properties, heat treatment, lubrication conditions, temperature, loading conditions, bearing geometry, internal clearance and so on. In this paper, we analyze the relation between loads and deformations of wheel bearing units. On the basis of it, we calculate the endurance life of wheel bearing units and suggest a method to determine the initial contact angle to achieve a maximum endurance life with considering stress concentration.

• Journal of Korean Society for Quality Management
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• v.36 no.3
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• pp.1-12
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• 2008

Obtaining the accurate final importance of each customer attribute (CA) is very important in the house of quality(HOQ), because it is deployed to the quality of the final product or service through the quality function deployment(QFD). The final importance is often calculated by the multiplication of the relative importance rate and the competitive priority rate. Traditionally, the sample mean is used for estimating two rates but the dispersion is ignored. This paper proposes a new approach that incorporates statistical significance to consider the dispersion of rates in determining the final importance of CA. The approach is illustrated with a design of car door for each case of crisp and fuzzy numbers.