• International Journal of Fluid Machinery and Systems
• /
• v.1 no.1
• /
• pp.148-154
• /
• 2008

The Wells turbine rotor consists of several symmetric airfoil blades arranged around a central hub, and the stagger angle is 90 degrees. These characteristics simplify the total construction of OWC type wave energy converters. Although the Wells turbine is simple, the turbine produces a complicated flow field due to the peculiar arrangement of blades, which can rotate in the same direction irrespective of the oscillating airflow. In order to understand these flows, flow visualization is carried out with an oil-film method in the water tunnel. This research aims to analyze the mechanism of the 3-D flows around the turbine with the flow visualization. The flow visualization explained the influence of attack angle, the difference between fan-shaped and rectangular wings, and the sweep angle.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.10
• /
• pp.54-59
• /
• 2019

The final reduction drive in tactical vehicles has a wear-pad that helps to maintain adequate end floating when the hub assay operates. The input axis and sun gear move repeatedly with the axis when tactical vehicle is operating. The hub assay is designed so that the wear pads won't seize during operation. Seizure of the wear pads during operation results in oil leakage. In our study, the fault mechanism was analyzed to prevent the seizure of the wear pads and an optimal design for the shape and material of the wear-pad was explored. We then observed the changes in temperature, shape, and material of several important parts.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.11
• /
• pp.1521-1528
• /
• 2011

We studied the material properties for reliability improvement in finite element analysis results for a nitrile butadiene rubber hub-bearing seal and for a carbon-filled rubber mount used in a vehicle. It was difficult to measure the material properties of hundreds of types of rubber for the mount design. Thus, we suggested that the engineering stressstrain relations from pure shear test data could be synthesized by using simple tension data and Poisson's ratio. We defined Poisson's ratio by using a function of principal stretches to synthesize the stress-strain relations for a pure shear test. A transformation of the pure shear data was applied to the experimental values to obtain the predicted results when the strain approaches 100%. In the finite element analysis for the contact force of a hub-bearing seal, the strain results that used the transformation of the pure shear data and simple tension data almost corresponded to the experimental values. Ogden constants were used to analyze.

• Journal of the Korean Society for Heat Treatment
• /
• v.27 no.2
• /
• pp.65-71
• /
• 2014

SMF9060 material is a Fe-based powder sintered alloy that is used for several automobile components such as Synchronize Hub, oil pump and transmission. These components are required excellent wear resistance and durability. In this study, we have performed a dry wear test at the ambient air and Ar gas conditions in the room temperature, and a lubricant wear test at the room temperature and engine oil temperature of $100^{\circ}C$. The amount of wear volume and coefficient friction are measured by a Profilometer and a Ball on disk type wear tester. The wear volume in Ar gas condition was a little higher than that in the ambient air condition. However the wear volume in the lubricant wear condition was much lower than in the dry wear condition. XRD analysis of the debris in Ar gas condition showed that the oxide film was not formed.

• Journal of Navigation and Port Research
• /
• v.29 no.6 s.102
• /
• pp.501-508
• /
• 2005

The purpose of this paper is to present the alternatives for improving coostal shipping logistics system to be a logistic hub-nation with a competitive edge. For this purpose, major environmental factors in Northeast Asia and accordingly its effects are analyzed And then the effects of coastal shipping system's development strategy is analysed using Structural Equation Model and Multiple Regression Model. Research results show that three types of coastal shipping development strategy( connected transportation system, structure of coastal shipping system, governmental support policy) will contribute much to being a logistics hub-nation. From the results, some implications are derived as follows. Firstly, environmental-friendly balanced ocean-coastal transport system is required Secondly, a excusive feeder port, Ro-Ro ship & high-speed ship are necessary to establish the one-stop logistics service system Finally, governmental support policy and subsidy(tax-exempted oil & various tax benefits) are required to reactivate lagged coastal shipping system to be a logistic hub-nation with a competitive edge.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.29 no.1
• /
• pp.441-449
• /
• 2005

The purpose of this research is to present the improvement measure of lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge. For this purpose, this research tries to find out major northeast asia environment factors and accordingly the effects of its. The effects of coastal shipping system's development strategy is analysed by structural equation model and multiple regression model. Research results show that three types of coastal shipping developing strategy(connected transportation system, structure of coastal shipping system, governmental support policy) will contribute much to be logistic hub-nation. The contribution effects is increasing cargo from strengthened feeder transport system and maximizing logistic service &minimizing logistic costs. From the result, some implications are derived as follow. First, familiar environmental balanced ocean-coastal transport system is required. Second the one-stop logistic service system is necessary to build excusive feeder port, and to establish Ro-Ro ship & high-speed ship, etc.. Third, governmental support policy and subsidy(tax exempted oil & various tax benefits) are required to bring up lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge.

• International Commerce and Information Review
• /
• v.10 no.4
• /
• pp.579-595
• /
• 2008

Medical tourism is a contemporary phenomenon which has its roots in both tourism and health care industry. This market has grown significantly' for the last 10 years. The purpose of this study is to suggest strategies to develop medical tourism in Korea by studying cases of the medical tourism developed countries such as Singapore, Malaysia, India, Thailand as well as analysis medical tourists who has visited to H university hospital. In total of 254 medical tourists were analysed and the results of the study are followed: Korean government need to appease medical law to be able to attract more medical tourists; medical industry and tourism industry need to develop Korean specialized medical tourism package, Middle-Eastern markets, where the oil money exists, should be developed.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.12
• /
• pp.55-61
• /
• 2018

Purpose - It suggests that making a policy and strategies for a way of Dubai has a strong priority strategy on science and technology by using much oil dollars to prepare risk when oil dollar's decrease. This has been now investigated how the leading innovator has changed the periphery countries. Research design, data, and methodology - Analyze policy, status, what other neighbouring Middle East countries also want to benchmark a successful case of a leading Dubai strategy. Higher manpower is needed absolutely to develop S&T. and etc. Dubai and Arab countries establish university to nurture as well as invite the talented manpower from overseas to recover deficient manpower. Dubai built totally academy city and invited branch of the overseas famous university, and Saudi Arabia built university(KAUST) and invite faculty and support good scholarship for students. Abrab countries especially, This is studied the process of differentiating and integrating the migrant workers of these cities into the globalized cities. This has resulted in large-scale employment for foreign and local companies in these cities and the spread of science and innovation. Results - Dubai supports venture or SMEs by using a strong priority strategy and attracts foreigner's investor, with which the neighbouring countries have been preparing together for 4th wave. It demonstrates that the gravitational model has been activated from neighboring countries of innovation science to create Dubai's hub. The maturity of long-term urban innovation is related to innovation capability through the national response and review. As a result, the flow of skilled international migration has been localized because of the mutual intersection with the local employment structure, and the development has spread as it spreads to neighboring countries. Conclusion - For the exploiting of new Distribution market in the neighbouring countries, Middle East countries' a strong priority strategy on S&T and education system give an influence on economic situation of the 4th wave in the world and world order of leading by USA, Japan, or EU, and etc. This is due to the creation of clusters in the form of SEZs, friendly industrial policies and world-class infrastructure and innovation development. Its neighbours benchmark the cases of distribution of science innovation and centralizes the surrounding people.

• Journal of Korea Port Economic Association
• /
• v.36 no.4
• /
• pp.1-16
• /
• 2020

Since Korea has excellent port infrastructure and competitive petrochemical complexes, there is plenty of potential for creating an oil hub in Northeast Asia. In particular, Ship-to-Ship (STS), which creates high added values, contributes greatly to the national economy. In this study, the liquid cargo volumes of chemical industrial products, refined petroleum products, and crude oil were analyzed at the national and regional (Busan, Ulsan, and Yeosu/Gwangyang) levels. Additionally, a Granger causality analysis was performed between imports, exports, and transshipments, in pairs. ADF, PP, and KPSS were analyzed for the unit root test. In addition, the VAR model and expanded VAR model suggested by Toda and Yamamoto were used for further analyses. Findings revealed a difference in Granger causality depending on the region or cargo type. These findings suggest that policies and incentive schemes for ports need to be differentiated according to the region and cargo types. In addition, the different patterns in the relationship between transshipments and import-export petrochemical cargoes should be considered.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2002.05a
• /
• pp.129-134
• /
• 2002

This study is focused on the layout design with sizing for the main propulsion shafting with controllable pitch propeller system. For appropriate design and successful manufacturing of controllable pitch Propeller system, it is based on specifications to be required from the customer as well as the stresses calculation and analysis of main propulsion system for hollow shafting. And it must be performed according to the U.S military specifications MIL-STD-2189(SH) with drawing of NAVSHIPS 803-2145807, and also the stress analysis by applying safety factor. The results are as follows : 1. For the main propulsion system with controllable pitch propeller, it is designed the following items propeller diameter, hub diameter, dimensions of oil distribution or actuating unit based on shaft mounting type, diameters of propeller and intermediate shaft, dimension of split muff coupling, coupling flange thickness and of coupling bolt diameter. 2. As the results, we can get complete our own design ability for the main propulsion shafting with controllable pitch propeller system with critical data which are necessary to establish shafting arrangement from the ship building companies.