• KSTLE International Journal
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• v.7 no.2
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• pp.51-55
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• 2006

In order to design an effective foot surface which can provide adequate friction for a self-propelled medical microrobot moving inside the small intestine, frictional mechanisms between the small intestine inner wall and the foot surface of the robot must be understood. In this paper, mechanical interlocking effect was considered to design the surface of the foot that can generate the desired frictional force. The concept of the design was derived from the hookworm that lives inside the small intestine. Hookwarms are known to adhere to the small intestine wall by interlocking with villi on the surface of the small intestine. The interlocking mechanism was considered as the main frictional mechanism for the design of the microrobot foot surface in this work. 2 mm and 6 mm diameter solid and hollow cylindrical shaped foot specimens were designed and tested to assess the frictional force between the specimens and the porcine small intestine specimen.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.151-162
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• 1997

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. In this study, the vertical movement of boom tips due to unevenness of ground in paddy fields was investigated, and an active pendulum suspension control system was designed and tested for compensating the movement and balancing the boom to the ground. The results for testing the performance of the control system showed that the system could balance the boom both in flat and inclined fields. The active pendulum control system developed in this study could be properly used for improving spraying performance of a boom sprayer.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.2
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• pp.1-10
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• 2003

It is important to understand the flow characteristics such as wave and wake development around a ship for the design of the hull forms with better resistance and propulsive performance. The experimental results explicating the local flow characteristics are also invaluable for validation of the physical and numerical modeling of CFD codes, which are recently gaining acknowledgements as efficient tools for hull form evaluation This paper describes velocity and wave profiles measured in the towing tank for the KRISO 138K LNG Carrier (KLNG) model with propeller and rudder. The results contained in this paper can provide the valuable information on the effect of propeller and rudder on stern flow characteristics of the modern commercial hull form, furthermore, the present experimental data will provide important database for CFO validation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.88-89
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• 2013

For the purpose of launching strikes, initial survivability of self-propelled artilleries is of crucial importance despite the fact that they are mobility weapon systems. This study identifies the combat placement possibility of the reinforced concrete box-type artillery positions, which might enable the replacement of the current igloo-types, in terms of cost and protection capability. In the numerical analysis the obtained numerical values have proved that these facilities have sufficient protection capability. In addition, it could be concluded that these facilities are also cost-competitive, if more than five positions are constructed simultaneously.

• Bulletin of the Society of Naval Architects of Korea
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• v.24 no.2
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• pp.36-46
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• 1987

This paper presents the results of seakeeping tests in a container ship model in irregular head waves. A time domain signal generating procedure is devised so that the wave maker behaves in accordance with the specified wave spectrum. The surface elevation of generated waves is measured and analysed to render the recorded wave spectrum for comparison with the specified one. Correction is made to the time domain signal until the differences between the two spectra become negligible. The motion responses and vertical acceleration of the self-propelled ship model are measured and analysed by both the spectral and the double amplitude methods. The two methods give nearly same statistical values. Finally the recorded spectra are compared with those calculated from the frequency domain motion analysis to show the credibility of the experimental results.

• Journal of the Korean Society of Systems Engineering
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• v.14 no.2
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• pp.1-7
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• 2018

The research and development stage can improve the goal level of the project through systematic operation and management of systems engineering. The test evaluation tasks in the R&D process have a lot of connections with the system engineering in terms of requirement management, and the methodology for deriving the requirements when establishing the test evaluation items has been consistently required. In this paper, we propose the process of effectively establishing and using QFD (Quality Function Deployment), a tool to manage customer requirement, and drawing up HOQ (House of Quality) in the search and exploratory development stage of the self - propelled mortar project.

• Advances in nano research
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• v.13 no.3
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• pp.269-284
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• 2022

Nanomachines can be pretty helpful in curing diseases. Nanomototors, thanks to their self-propelled feature, are one of the best structures to be utilized as drug delivery devices. These devices have been employed in biomedical application as they can improve the efficiency of drug delivery. In this study stability of a designed nanomotor in the bloodstream is investigated when the physical activities have been done considering the physical activities. Sports training, as well as exercise enhance the bloodstream, and this factor can significantly impact the drug-delivery quality. The mathematical simulation of nanomotor movement in the condition of the sports is done based on the mechanical sciences, and the impact of various essential parameters is discussed in detail.

• The Korean Journal of Franchise Management
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• v.2 no.1
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• pp.61-73
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• 2011

Supermarket Franchising, as a relatively new mode of retail business, is often regarded as one of the two hallmarks of the "Modern Logistics Revolution". After more than ten years of development, franchise supermarkets have been a rising force in retail business in China. As a product of a highly-developed commercial economy, franchise supermarkets mainly deals in foodstuffs and other daily necessities, featuring low cost, high turnover rate, low prices and diversified inventory. Propelled by the conveniences that come with open shelves and self-service shopping, franchise supermarkets have been growing very rapidly and the rise of many franchise supermarket brands bears testimony to its growth potential and profitability. Meanwhile, in the backdrop of this boom, some franchise supermarkets are going bankrupt. This paper analyzes the current status of franchise supermarkets and some factors bearing on their core competencies, so as to close the competitiveness gap with international retail giants.

• Journal of Mushroom
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• v.16 no.4
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• pp.250-256
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• 2018

The windrow turner, widely used for outdoor fermentation of mushrooms in Europe, has been improved by using rice straw instead of wheat straw in accordance with Korea's actual situation. It was compared with conventional excavator work, and the results were as follows. Agitation performance was $81m^3/hr$, which was 2.8 times higher than $28.6m^3/hr$ of excavator. As a result of the temperature distribution in the pile at the end of the fermentation stage, it was found that the temperature at the lower part of the pile was $5^{\circ}C$ higher than that of conventional pile. This was more favorable for aerobic fermentation. Meanwhile, ash ratio of prototype ($30.9{\pm}1.1%$) was higher than that of control $28.4{\pm}1.6%$. In the case of prototype turner agitation, the yield of mushroom cultivation was $880kg/66m^2$, that was 22.9% higher than the conventional control yield of $716kg/66m^2$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.595-609
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• 2020

In this study, we propose a decentralized mathematical model for predictive control of a system of multi-autonomous unmanned aerial vehicles (UAVs), also known as drones. Being decentralized and autonomous implies that all members make their own decisions and fly depending on the dynamic information received from other unmanned aircraft in the area. We consider a variety of realistic characteristics, including time delay and communication locality. For this flocking flight, we do not possess control for central data processing or control over each UAV, as each UAV runs its collision avoidance algorithm by itself. The main contribution of this work is a mathematical model for stable group flight even in adverse weather conditions (e.g., heavy wind, rain, etc.) by adding Gaussian noise. Two of our proposed variance control algorithms are presented in this work. One is based on a simple biological imitation from statistical physical modeling, which mimics animal group behavior; the other is an algorithm for cooperatively tracking an object, which aligns the velocities of neighboring agents corresponding to each other. We demonstrate the stability of the control algorithm and its applicability in autonomous multi-drone systems using numerical simulations.