• Journal of Digital Contents Society
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• v.18 no.3
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• pp.607-612
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• 2017

The use of RaspberryPi in building an embedded system may be difficult for users in understanding the circuit and the hardware cost. This paper proposes a solution that can test the systems virtually. The solution consists of three elements; (i) editor, (ii) interpreter and (iii) simulator and provides nine full modules and also allows the users to configure/run/test their own circuits like real environment. The task of abstraction for modules through the actual circuit test was carried out on the basis of the data sheet and the specification provided by the manufacturer. If we can improve the level of quality of our solution, it can be useful in terms of cost reduction and easy learning. To achieve this end, the electrical physics engine, the level of interpreter that can be ported to the actual board, and a generalization of the simulation logic are required.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1358-1364
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• 2016

Maritime accidents caused by a ship include collisions, sinking, stranding and fire etc. This study is intending to consider fire accidents among such diverse marine accidents. It is much likely that various sorts of fires break out because crewmen are living in a narrow space for long periods of time consequent on the ship's characteristic of sailing on the sea. According to the ship fire survey, about 50% of the total fire accidents occurred at an engine room, and the main fire origin was analyzed to be oil. In addition, ship fire breaks out in the order of baggage racks and living quarter. In short, the survey indicates that all sorts of fires belonging to A, B, C and D-class have occurred. This study, targeting an actual passenger ship 'A', found the response time to evacuation, during which the people on board a ship recognize the outbreak of fire, and act, and the travel time for evacuation which is the actual travel time. In addition, this study carried out a simulation through the special program for fire analysis - FDS (Fire Dynamics Simulator) in order to find the effective evacuation time, i.e. life survival time. Particularly, this study did comparative analysis of the influence on the survival of passengers and crew based on the collected simulation data by fire size and sort. As a result of the analysis, it was found that when examining the only actual evacuation movement time excepting the response time to evacuation, people are safe by completing evacuation before the effective evacuation time only in case fire size is 100Kw among all sorts of fires. In other words, in case of the outbreak of fire more than 1 MW, it was found to fail to meet evacuation safety regardless of fire size.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.30-35
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• 2000

The experimental study on the lift-off height of diffusion flames was conducted to investigate the damage of swirl-coaxial injector used in $GO_2$/kerosene rocket engine during initial stage of ignition. To investigate the causes of damage and to prevent further damage of the injector, experimental injector was designed and hot fire tests were performed with varying propellant momentum ratio($\frac{Momentum of {GO_2}}{Momentum of Kerosene}$) from 1 to 12. In experimental coaxial injector, kerosene is sprayed from the central nozzle with swirl and $GO_2$ sprayed around the kerosene nozzle in the direction parallel to the axis of combustion chamber. Chamber pressure are close to the atmospheric condition. Lift-off height was measured by still images from camcoder and average values were used as data.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.133-141
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• 2020

Up to date cosmetic OEM/ODM (original equipment manufacturing/original development manufacturing) industry receives attention as a future growth engine due to steady growth. However, because of limited research and development capability, many companies have employed commercial management platforms specialized for large-sized companies; thus, overall system effectiveness and efficiency is low. Especially, MRP (material requirement planning) system introduced originally in 1970s is employed to calculate the requirement of the parts. However, dynamic nature of production lead time usually results in incorrect requirements. In addition, its algorithm does not consider the capability of the production resources. Also, because the commercial MRP system calculates all subcomponent for fixed period, the more goods have subcomponent, the slower calculation is. Therefore, conventional MRP system cannot respond complicated situation in time. In this study, we will suggest a new method that can respond to complicated situations resulting from short lead time and urgent production order in Korean cosmetic market. In particular, a distributed MRP system is proposed, that consists of multi-functional and operational modules, based on the characteristic of the BOM (bill of material). The distributed MRP system divides components (i.e. products and parts) into several fields and decrease the problem size; thus, we can respond to dynamically changed data any time. Through this solution, we can order components quickly, adjust schedules and planned quantity, and manage stocks reasonably. In addition, a prototype of the distributed MRP system is presented in this paper, in which ERP (enterprise resource planning) sever data is associated with an excel spreadsheet via MSsql. System user interface is implemented by a VBA (visual basic for applications) tool. According to a case study, response rate for delivery and planning achievement rate were enhanced about 20%, and inventory turnover was also decreased. Consequently, the proposed system improves overall profit.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.3
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• pp.397-419
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• 2022

Smart agriculture has emerged to be a solution to the global food crisis and a new growth engine in the era of the Fourth Industrial Revolution. The purpose of this study is to reveal the spatiality of smart agriculture by analyzing smart agriculture policies in major countries and examining how major's agricultural knowledge and experience are expressed in specific agricultural environment. I selected China, Japan, the Netherlands, and the United States as representative examples. In the analysis of agricultural policy, the direction, governance and main areas and technologies were focused. As a result, it is found both standardization strategy and the localization strategy work at the same time. Standardization strategies decontextualize technologies and policies from the economic, social, cultural, and ecological contexts of region. The regionalization strategy builds a smart agricultural model for each country with reflecting geographical characteristics. This study could be for facilitating further researches on geographies of agricultural technology and agricultural knowledge production.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.2_2
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• pp.307-312
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• 2020

This study presents problems and improvement measures for the supply rate of single-alarm detector and fire extinguisher installed in households. Statistics from the NFDS show that 18 percent of all fires and 45 percent of deaths occurred in residential buildings over the past eight years. It was less than 60% that households be equipped rate of basic fire-fighting systems by 2019. In this study, I analyzed the law and statistics of fire to devise a method for fire safety. I proposed that the basic fire-fighting systems is be equipped in households. Like this : First, a free distribution policy for the over 60 years of age and Areas where is fire engine difficult to enter. Second, the policy of adopting safety pay in disaster. Third, the policy of expanding supply through the revision of the Licensed Real Estate Agents Act. Fourth, the policy of self-regulating installation by safety education and set up a data base system. Fifth make a law of household's National Fire Safety Standards.

• The Journal of the Korea Contents Association
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• v.6 no.9
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• pp.98-107
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• 2006

By improving performance of mobile machine(3D engine, 3D accelerator chip set, etc) and developing wireless network technology, a demand for actual contents of users is being increased rapidly. But, there are some difficulties yet for the speedy development of actual contents because of the limitation of development resources that is dependent on each mobile device's different performance. In general, much of the animated character-creation work for mobile environment is still done manually by experienced animator with the method of key frame processing. However, it needs a lot of time and more costs for creating motion. Additionally, it is possible to cause a distortion of motion. In this paper, I solved the difficulties by using a optical motion capture system, it was able to acquire accurate motion data more easily and quickly, and then it was possible to make 3D dance contents efficiently. Also, I showed techniques of key reduction and controlling frame number for using huge amounts of motion capture data in mobile environment which requires less resources. In making 3D dance contents, using an optical motion capture system was verified that it was more efficient to make and use actual-reality contents by creating actual character motion and by decreasing processing time than existing method.

• Journal of Technology Innovation
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• v.27 no.2
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• pp.37-71
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• 2019

How has the passenger car's architecture evolved? In the meantime, the discussions on the car architecture have been mixed, i.e., integral, modular, and the coexistence of two types. Therefore, in this study, we aim to develop two indices can measure the degree of modularization of passenger car and its all modules using global trade data. By applying the indices to the framework of architecture positioning that reflects the hierarchical structure of a product, we examined that the degree of modularization of the passenger car architecture has been enhanced. Meanwhile, the degree of modularization differs across the modules that make up the car. Specifically, we observed the higher degree of modularization in front-end, cockpit and seat modules. Whereas, we found that body module had a relatively low degree of modularization. In particular, we observed that the platform of passenger car has notably modularized due to carmakers' efforts to achieve model diversification and reduction of cost and period in new product development at the same time. Interestingly, we showed that three modules, i.e., engine, chassis (relatively less modularized), and transmission (relatively highly modularized), had a different level of modularization, even if they commonly make up the platform. We contribute to the suggestion for analytical approaches that examine the degree of modularization and its progress longitudinally. In addition, we propose the necessity of decomposition of a system into elements in a study of product architecture, considering the possibly distinctive progress of modularization across the elements.

• Tribology and Lubricants
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• v.34 no.5
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• pp.197-207
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• 2018

Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.

• Journal of Science Education
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• v.32 no.1
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• pp.47-60
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• 2008

The Ministry of Science and Technology has been planning various events and carrying them out as the effort for promotion and popularization of science. The ministry has made followings: i)Science culture year, 2004 ii) Physics year, 2006 iii)Chemistry year, 2007 iv)Biology year, 2008. Especially, in 2006 the ministry held various exhibitions and contests about chemistry. The science play "Oxygen" had been presented in the whole country, 2006. From 2006 to 2007 the moving science museum had been displayed many times in the whole country. The national broadcast media KBS made a special program and televised several times to commemorate the year of chemistry. Like that in 2006 the chemistry approached to general people. In these surroundings, we wondered how chemistry was expressed in daily newspaper and how the general public accepted chemistry in the year of chemistry, 2006. So we selected four daily newspaper and researched descriptions about chemistry then analyzed the image of chemistry in that descriptions. When we research, we first selected 5 words of high frequency. On the internet research engine we used these 5 words and searched descriptions. We read and sorted descriptions which were more connected to chemistry. Finally we analyzed the images of descriptions(affirmative or negative) and character. The chemistry's image on newspaper descriptions influences people greatly. Because that is the easiest channel.