• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.106-116
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• 2011

USN(Ubiquitous Sensor Network) environment permits us to access whatever information we want, whenever we want. The technologies to provide a basement to these environments premise an accurate location establishment. Especially, ITS(Intelligent Transportation Systems) is easily constructed by applying USN technology. Localization can be categorized as either Range-based or Range-free. Range-based is known to be not suitable for the localization based on sensor network, because of the irregularity of radio propagation and the additional device requirement. The other side, Range-free is much appropriated for the resource constrained sensor network because it can actively locate by means of the communication radio. But, generally the location accuracy of Range-free is low. Especially, it is very low in a low-density environment. So, these two methods have both merits and demerits. Therefore, it requires a new method to be able to improve tracking accuracy by combining the two methods. This paper proposes the tracking scheme based on range-hybrid, which can markedly enhance tracking accuracy by effectively using the information of surrounding nodes and the RSSI(Received Signal Strength Indication) that does not require additional hardware. Additionally, we present a method, which can improve the accuracy of vehicle tracking by adopting the prediction mechanism. Simulation results show that our method outperforms other methods in the transportation simulation environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.310-316
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• 2016

We propose a novel contact-free transportation system in which an axial electrodynamic wheel is applied as an actuator. When the electrodynamic wheel is partially overlapped by a fixed conductive plate and rotates over it, three-axis magnetic forces are generated on the wheel. Among these forces, those in the gravitational direction and the lateral direction are inherently stable. Therefore, only the force in the longitudinal direction needs to be controlled to guarantee spatial stability of the wheel. The electrodynamic wheel consists of permanent magnets that are repeated and polarized periodically along the circumferential direction. The basic geometric configuration and the pole number of the wheel influence the stability margin of a transportation system, which would include several wheels. The overlap region between the wheel and the conductive plate is a dominant factor affecting the stiffness in the lateral direction. Therefore, sensitivity analysis for the major parameters of the wheel mechanism was performed using a finite element tool. The system was manufactured based on the obtained design values, and the passive stability of a moving object with the wheels was verified experimentally.

• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.526-534
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• 2023

To improve usability of super sweet corn, extracts were prepared with hydrolytic enzyme and changes in physicochemical and antioxidant properties were analyzed. Soluble solids and reducing sugars contents were higher in all enzyme treatment groups than in the control. When enzyme treatment time increased, contents of soluble solids and reducing sugars were also increased. There was no significant difference in lightness between treatment groups, with redness showing the highest value in the control and yellowness showing the highest value in the invertase treatment group. Free sugar content in the control was the lowest. However free sugar content in the enzyme combination treatment group was increased by more than four times compared to that in the control. Contents of ascorbic acid, flavonoids and polyphenols were higher in the enzyme treatment group than in the control. In particular, the enzyme combination treatment group showed the highest content. DPPH and ABTS radical scavenging abilities were significantly higher in all enzyme treatment groups than in the control. Radical scavenging abilities of cellulase treatment group and enzyme combination treatment group showed high activity. The activity increased when enzyme treatment time increased. The combined enzyme treatment method for super sweet corn was suitable for food processing.

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.235-240
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• 1999

• Journal of The Korea Institute of Healthcare Architecture
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• v.20 no.2
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• pp.27-35
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• 2014

Purpose: The number of the transportation poor has been steadily increased, and also the social perspective toward the disabled has been changed. Thus, Universal Design has been needed. In particular, the unknown majority of the transportation poor have frequently used the urban railway facilities which should reflect the ideals and principles of Universal Design. However, previous research has not focused on the study on critical factors of Universal Design. Based on this observation, the present study aims to find out Universal Design critical factors of urban railway station. Methods: This study explores the criteria of planning Universal Design in the urban railway station by analyzing and comparing the similar criteria used in both domestic areas and foreign countries. Result: Findings from this study are as follows. First, we found out the critical factors of Universal Design in the urban railway station by comparing and analyzing the similar criteria previously used. Second, this study also suggests the better directions toward the domestic criteria relating to the urban railway system. Third, we found the need of the universal standard as well as individually corresponding strategy. Moreover, we found the need of preparing the critical factors for the physical environments as well as the human service. Implications: The further research on findings of the planning criteria will have been continued on the basis of findings of the present study.

• Computers and Concrete
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• v.26 no.2
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• pp.161-173
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• 2020

Shear keys in precast concrete segmental bridges (PCSBs) are usually match-casting which is very labour intensive. In this research, an innovative match-casting-free construction was proposed by leaving small gap between the convex and the concave castellated shear keys in the joints of PCSBs. Specimen experiment, shear strength analysis and numerical simulation were conducted, investigating the loading performance of this new type of dry joints, the gap dry joints. Compared with match-casting joint specimens, it has been found from experiment that shear capacity of gap joint specimens significantly decreased ranging from 17.75% to 42.43% due to only partially constrained and contacted in case of gap dry joints. Through numerical simulation, the effects of bottom contacting location, the heights of the gap and the shear key base were analyzed to investigate strength reduction and methods to enhance shear capacity of gap joint specimens. Numerical results proved that shear capacity of gap dry joints under full contact condition was higher than that under partial contact. In addition, left contact destroyed the integrity of shear keys, resulting in significant strength reduction. Larger shear key base remarkably increased shear capacity of the gap joint. Experimental tests indicated that AASHTO provision underestimated shear capacity of the match-casting dry joint specimens, while the numerical results for the gap dry joint showed that AASHTO provision underestimated shear capacity of full contact specimens, but overestimated that of left contact specimens.

• Structural Engineering and Mechanics
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• v.54 no.2
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• pp.199-219
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• 2015

This paper presents the non-destructive evaluation of a high-speed railway bridge using train-induced strain responses. Based on the train-track-bridge interaction analysis, the strain responses of a high-speed railway bridge under moving trains with different operation status could be calculated. The train induced strain responses could be divided into two parts: the force vibration stage and the free vibration stage. The strain-displacement relationship is analysed and used for deriving critical displacements from theoretical stain measurements at a forced vibration stage. The derived displacements would be suitable for the condition assessment of the bridge through design specifications defined indexes and would show certain limits to the practical application. Thus, the damage identification of high-speed railways, such as the stiffness degradation location, needs to be done by comparing the measured strain response under moving trains in different states because the vehicle types of high-speed railway are relatively clear and definite. The monitored strain responses at the free vibration stage, after trains pass through the bridge, would be used for identifying the strain modes. The relationship between and the degradation degree and the strain mode shapes shows certain rules for the widely used simply supported beam bridges. The numerical simulation proves simple and effective for the proposed method to locate and quantify the stiffness degradation.

• Journal of Navigation and Port Research
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• v.36 no.9
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• pp.763-767
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• 2012

The ratio of the mobility handicapped person is about 25.8% of the total population in Korea(MCT, 2006). In order to prepare for the enforcement of the "Transportation Services Improvement Act for the Mobility Handicapped People"(MCT, 2006), various equipments and installations should be developed to ensure appropriate safety level for the mobility handicapped persons in maritime transportation. While approximately 10 million people are using domestic passenger vessels annually, preferences for maritime transport is very low, especially for the mobility handicapped. This study reviewed a current status of the mobility handicapped person in domestic passenger ship and analysed the improvement plan for them. To investigate the current status of domestic passenger vessel usage by the mobility handicapped, to analysis the requirements for amenities necessary for the mobility handicapped and select the ones to be developed based on the investigated results and to do feasibility study of barrier-free ship.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.471-475
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• 2006

For years, Korea, China and Japan have been continuously increasing intra-trade. In addition, by concluding FTA (Free Trade Agreement) among Korea, Japan and China, the trade capacity will be increased. In this way, the increasing trade capacity will induce to change north-east Asian economy. This paper researches which method is more economical and efficient in the aspect of the transportation time and distance, after comparing the existing marine transportation network with new intermodal transportation network considering TKR.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.365-372
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• 2015

This paper reviews the one of problems that may occure for the tram operating in Korea, it's a free-riding problem, I analyzed the feasibility of combining the introduction of world-class technology solution "IT". It is under review the introduction of tram in Su-won city, Chang-won city, Wi-Rye new town. Free-riding is one of the biggest issues of any agency that operates the public transportation system. It has been acting as the main factors threatening the financial integrity of the operating agency, and the ratio of free-riding is further increased. In this paper, I want to build a foundation for the development of the system by analyzing the economic feasibility for the introduction of free-riding prevention system.