• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.84-98
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• 2021

The hydrodynamic characteristics of amphibious assault vehicles are investigated using commercial CFD code, STAR-CCM+. Resistance performances of a displacement-type vehicle and a semi-planing type vehicle are analyzed in calm water. The self-propelled model is also computed for the semi-planing type vehicle. All computations are performed using an overset mesh system and a RANS based flow-solver coupled with a two-degree of freedom equations of motion. A moving reference frame is applied to simulate revolutions of impeller blades for a waterjet propulsion system. Grid dependency tests are performed to evaluate discretization errors for the mesh systems. The numerical analysis results are compared with the experimental results obtained from model tests. It is shown that RANS is capable of investigating the resistance and self-propulsion characteristics of high-speed amphibious assault vehicles. It is also found that a fully covered side skirt, which is covering tracks, reduces resistance and stern trim, besides increasing propulsive efficiency.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.535-538
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• 2007

Since 1980s, the government has established the overall country development master plan for balance development of country, it set basic aim of restraint overcrowding of the metropolitan area and devising a regional balance development for development policy. But, new urban development master plan which if propelled has revised development master plan for stabilization of housing cost through supply housing in the metropolitan area, not reviewed discussion suitability of development plan with policy propulsion, efficient pre-plan, negotiation with local self-administration community, convergence opinion of local resident, environmental impact evaluation. therefore, we should suggest considerations related to policy and development when it propelled solution of housing inefficience in the metropolitan area and new urban development policy for harmony of central function in capital.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.33-43
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• 2019

A comparison between sea trial measurements and full-scale CFD results is presented for two self-propelled ships. Two ships considered in the present study are: a general cargo carrier at Froude number $F_n=0:182$ and a car carrier at $F_n=0:254$. For the general cargo carrier, the propeller rotation rate is fixed and the achieved speed and trim are compared to sea trials, while for the car carrier, the propeller rotation rate is adjusted to achieve the 80% MCR. In addition, three grids are used for each ship in order to assess the grid refinement sensitivity. All simulations are performed using the Naval Hydro pack based on foam-extend, a community driven fork of the OpenFOAM software. The results demonstrate the possibility of using high-fidelity numerical methods to directly calculate ship scale flow characteristics, including the effects of free surface, non-linearity, turbulence and the interaction between propeller, hull and the flow field.

• Journal of Internet Computing and Services
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• v.25 no.3
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• pp.9-18
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• 2024

Digital therapy has emerged as a novel treatment modality, propelled by advancements in information and communication technology. In the last five years, there has been a substantial surge in research publications addressing digital therapeutics (DTx) interventions, signaling a sustained upward trajectory in this field. The dynamic nature of computer science, marked by continuous innovation and development, underscores the need for agile adaptation to rapid changes. Consequently, computer science education is compelled to offer students insights into the latest trends. This research endeavors to contribute to the evolving landscape by developing textbooks that impart knowledge about DTx, an integration of information technology. The study focuses on the application of these textbooks to elementary and middle school students in South Korea. The instructional materials have been carefully organized to enable students to learn about the principle of Attention Deficit Hyperactivity Disorder (ADHD) DTx at the elementary level and the DTx that can prevent and address the digital drama at the middle school level. Based on the application of the textbook, students who received instruction using the textbook showed statistically significant improvements in all subcategories of creative problem-solving ability, including idea modification, visualization, task focus, analogy, idea generation, and elaboration (p<.01). Additionally, there were statistically significant changes in students' self-efficacy before and after using the textbook, with negative efficacy decreasing, and positive efficacy and social efficacy increasing (p<.001).

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.367-368
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• 2002

The design of capsule body for self-propelled endoscope is important from the frictional resistance point of view. The capsule should be able to overcome the frictional resistance in order to move along the intestine. The motivation of this work was to gain a better understanding of the capsule body design on the frictional resistance of the capsule inside an intestine. A special experimental set-up was built to measure the frictional resistance as the capsule was being pulled inside the pig intestine specimen. Tests were performed with open and closed intestine specimens. Experimental data showed that smooth cylindrical capsule geometry resulted in the least frictional resistance. The resistance inside the closed intestine specimen was about four times higher than that of the open specimen. It is expected that the results of this work will be used to design the optimum propulsion system for the microendoscope.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.307-314
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• 2005

In recent years, many environmentally disastrous oil spill accidents from damaged vessels become worse especially when the early treatment is not prompt enough. To properly handle this type of accidents and prevent further disasters, international organizations establish and impose various rules and regulations. In assessing the damages and providing salvage operations, the propulsive performance of damaged vessels is of great importance, as well as for containing oil spill while the vessels are being towed or self-propelled. Until now, many naval hydrodynamics researches have focused on the propulsive performance in normal operating conditions and only a few studies for damaged vessels are found in literature. In this paper experimental method is used to study the Propulsive performance of a very large crude-oil carrier (VLCC) in .heeled and/or trimmed conditions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.77-82
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• 2018

Track shoes improve the off-road driving ability of tanks. The strength of the track shoe body directly affects the driving ability of tanks, self-propelled artillery, and armored vehicles. In this study, the design technique for track shoe body was investigated. To select the optimal design of track shoe body, three track shoe body models were suggested and compared. Tensile strength was calculated using computer-aided engineering (CAE) analysis. Compressive tests were conducted using the original tank sprocket because sprocket compression is critical to the lifespan of the track shoe body. As a result, one track shoe body design was selected and the process of track shoe body design was described.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.1
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• pp.61-72
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• 1999

A Technical Manual is the tool that offers a guidance to a maintenance engineer in order to exactly use and maintain of complicated weapon system. Because the modern weapon system are complex and functionality integrated, its quantity is massive. So We spend a lot of money on its publication and suspending recent information. To solve this problem, to reduce a risk of loss and use easily, this study develops the IETM(Interactive Electronic technical manual) which observes the CALS standard. This paper provide the development concept, environment, technic of IETM.

• Journal of the Korean Institute of Educational Facilities
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• v.7 no.1
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• pp.57-66
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• 2000

Learning for educating creative thinking and problem solving abilities and for future-oriented method should have appropriate laboratory, experimental equipments and appliances. Technology laboratory model pertinent to experiment or activity for educating creative persons is suggested in the following : (1) It is considered that many problems of current education result from an overcrowded classes. The number of students per laboratory should be $30{\sim}40$ persons. (2) There should be sufficient activity spaces for students. Unlike normal classrooms laboratory should have various tools and materials, information, facility and equipment. (3) Flexible activity spaces for various activities should be provided for groups and individuals. (4) Safety facilities should be provided sufficiently. (5) Learning experiences of collection, analysis and utilization of information should be given. (6) Laboratories should be designed to be a place for self-propelled learning. They should be designed to be able to learn by individuals and small groups after taking into consideration the individual differences as students differ in interest, curiosity and ability.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.448-457
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• 1996

Chemical application is one of the most important field operation in rice production . Rolling of a boom due to local unevenness and softness in fields causes a local under/over-application of spray. This study was conducted to develop a control system for balancing a boom. A boom mounting mechanism was modfied and a control algorithm was developed in the study. The results for testing the performance of the control system showed that the system could balance the boom in flat and inclined fields. This research can contribute to improve spraying uniformity in applying agricultural chemicals with a boom sprayers.