• Journal of Digital Contents Society
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• v.19 no.6
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• pp.1091-1096
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• 2018

The purpose of this paper is to provide a convenient platform for bus users and a platform to provide tourist services suitable for bus tourism as integrated services. Recently, the number of FIT tourists for recreational purposes using public transportation is increasing as the bus use environment is improved. Accordingly, we need a tourist platform that meets the needs of tourists. In particular, a bus information providing algorithm is implemented using a bus information public API to more conveniently use the bus information providing system, and a user use behavior data collection module and a data mining module To develop a contents platform based on a bus stop for bus tourism services to FIT tourists using public transportation.

• The Journal of Korea Robotics Society
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• v.15 no.2
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• pp.100-106
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• 2020

In the agricultural field, interests in research using robots for fruit harvesting are continuously increasing. Dual arm manipulators are promising because of its abilities like task-distribution and role-sharing. To operate it efficiently, the task sequence must be planned adequately. In our previous study, a collision-free path planning method based on a genetic algorithm is proposed for dual arm manipulators doing tasks cooperatively. However, in order to simplify the complicated collision-check problem, the movement between tasks of two robots should be synchronized, and thus there is a problem that the robots must wait and resume their movement. In this paper, we propose a heuristic algorithm that can reduce the total time of the optimal solution obtained by using the previously proposed genetic algorithm. It iteratively desynchronizes the task sequence of two robots and reduces the waiting time. For evaluation, the proposed algorithm is applied to the same work as the previous study. As a result, we can obtain a faster solution having 22.57 s than that of the previous study having 24.081 s. It will be further studied to apply the proposed algorithm to the fruit harvesting.

• Structural Engineering and Mechanics
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• v.75 no.2
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• pp.247-269
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• 2020

A finite strip formulation was developed for buckling and free vibration analysis of laminated composite plates based on different shear deformation plate theories. The different shear deformation theories such as Zigzag higher order, Refined Plate Theory (RPT) and other higher order plate theories by variation of transverse shear strains through plate thickness in the parabolic form, sine and exponential were adopted here. The two loaded opposite edges of the plate were assumed to be simply supported and remaining edges were assumed to have arbitrary boundary conditions. The polynomial shape functions are applied to assess the in-plane and out-of-plane deflection and rotation of the normal cross-section of plates in the transverse direction. The finite strip procedure based on the virtual work principle was applied to derive the stiffness, geometric and mass matrices. Numerical results were obtained based on various shear deformation plate theories to verify the proposed formulation. The effects of length to thickness ratios, modulus ratios, boundary conditions, the number of layers and fiber orientation of cross-ply and angle-ply laminates were determined. The additional results on the same effects in the interaction of biaxial in-plane loadings on the critical buckling load were determined as well.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.2
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• pp.135-154
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• 2007

The 3 Northeast Asian countries of Korea, Japan and China have been stricter to each other than to other countries of out-region in air liberalization. The prominent reason of this intra-regional protective policy in air transportation seems to be the difference in competitive strength of their national flag carriers. As the 3 countries realize the importance of their mutual cooperation in the region, since China grows to be one of the leading economies in the world and the intra-regional trade and visitors increase tremendously, they are now taking the policy of intra-regional air liberalization more vigorously than before. Especially air cargo liberalization is easier than air passenger liberalization because they realize that the development of open economy is based on free flow of logistics regardless of the competitiveness of their national flag carriers. As Korea is the leading country in the region to promote air liberalization, this paper reviews the importance and growing trend of air cargo, analyzes current air liberalization policy between Korea, Japan and China and the initial effects of open sky in the routes of Shandung-Korea, and suggests the new policies of air liberalization to promote free flow of air logistics.

• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.829-834
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• 2015

To decrease excessive sugar intake, and increase vegetable and calcium intake, we manufactured sugar free fruit-vegetable jam containing calcium and fructo-oligosaccharide to substitute for sucrose. We evaluated jam for physico-chemical and sensory properties. When the amount of apple was replaced with the amount of kale, $^{\circ}brix$ decreased, whereas there were no significant changes in pH. As the amount of kale increased, lightness and yellowness increased. However redness did not show trend to increase or decrease. In the texture profile analysis, hardness, springiness, cohesiveness, gumminess and chewiness significantly decreased with increased amount of kale, but adhesiveness gradually increased. The sensory parameters including taste, flavor, color, spreadability and overall acceptance of jam added 10.0~12.0% amount of kale were the highest acceptance. As the amount of kale added in the jam, sensory properties decreased. In general, when sugar free fruit-vegetable jam was manufactured, apple and kale ratio of 3:1 or 4:1 was considered appropriate.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.1-14
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• 2023

This study derives quantitative data on how much the fiscal deficit of subway operation agencies can be reduced in the process of charging free rides for the elderly in metropolitan subways during peak periods. In smart card data, every trip of elderly is recorded except fares. Therefore, it is required to establish a methodology for estimating the fares of elderly passengers and distributing them to subway opertation agencies as income. This study builds a simultaneous dynamic traffic allocation model that reflects the assumption that elderly selects a minimum time route based on the departure time. The travel route of the elderly is estimated, and the distance-proportional fare charged to the elderly is calculated based on this, and the fare is distributed by reflecting the connected railway revenue allocation principle of the metropolitan subway operating agencies. As a result of conducting a case study for before and after COVID-19 in 2019 and 2020, it is analyzed that Seoul Metro's annual free loss of 360 billion won could be reduced 6~8% at the morning peak (07:00-08:59), and 13~16% at the morning and afternoon peak (18:00-19:59).

• Journal of Ship and Ocean Technology
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• v.3 no.4
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• pp.1-14
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• 1999

The improved Green integral equation using the Kelvin-type Green function in known free of irregular frequencies where the integral over the inner free surface integral is removed from the integral equation, resulting in an overdetermined integral equation. The solution of the overdetermined Green integral equation is shown identical with the solution of the improved Green integral equation Using the B-spline higher order panel method, the overdetermined equation is discretized in two different ways; one of the resulting linear system is square and the other is redundant. Numerical experiments show that the solutions of both are identical. Using the present methods, the exact values and higher derivatives of the potential at any place over the wetted surface of the body can be found with much fewer panels than low order panel method.

• Journal of Ocean Engineering and Technology
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• v.19 no.3
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• pp.25-30
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• 2005

To predict rolling performance for a barge-type FPSO, the evaluation of correct nonlinear roll damping is critical. The square section of FPSO causes a considerable viscous damping effect. Free roll decay tests were carried out to estimate nonlinear roll damping for a barge-type FPSO, under three different conditions. The roll motion RAO was deduced from model tests in the wave condition of the wideband spectrum. In numerical calculation, the quadratic damping was considered as equivalent linear damping, using the results of free roll decay test. Tested roll performance in the JONSWAP wave spectrum was compared with numerical results. These two results shaw good agreement, in spite of the proximity of peak wave period and roll natural period.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.3 no.1
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• pp.14-22
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• 2000

The improved Green integral equation for the calculation of time-harmonic potentials in the radiation diffraction problem about a freely floating body in the presence of moderate or weak current is presented. The forward-speed Green function presented by Brard is used. The correct free surface boundary conditions on the physical free surface are employed as well as an appropriate boundary conditions on the non-physical inner free surface. The default in the existing Green integral equation as well as in the source integral equation is discussed in detail.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.443-450
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• 2014

The objective of this study is to examine the nonlinear fluid characteristics near and inside a moonpool in various sea conditions. We estimate the flow of the free surface in a moonpool taking into account the viscosity effect and the hydrodynamic forces that affects a moonpool and hull through CFD calculations. The comparison of horizontal forces per wave length shows that the hydrodynamic force is greater for the long wave length than short wave length, and the greatest hydrodynamic force acts on the moonpool when the wave length is equal to the ship's length. The horizontal force decreases as the wave amplitude decreases, and the hydrodynamic force acting on the moonpool in ${\lambda}=LBP$ is 10 times that in ${\lambda}=LBP/3$. The free surface demonstrates the piston mode, in which it oscillates up and down while remaining essentially flat, and the rise of the free surface level increases as the wave length increases. We can assume that the hydrodynamic force acting on the moonpool increases owing to the effect of a strong vortex for ${\lambda}=LBP$ and owing to the rise of the free surface level for ${\lambda}=LBP{\times}2$.