• Journal of Korea Port Economic Association
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• v.35 no.3
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• pp.93-108
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• 2019

This study aims to suggest a containerization plan for non-standardized cargo; it also reveals the significance of containerization in facilitating freight inducement and cargo creation for increasing the competitiveness of the Gwangyang port container terminal and checking excessive competition among terminal operators. Therefore, this study suggested a containerization plan and its significance by dividing 14 items, ones with low containerization ratios or undergoing containerization, bulk, and liquid cargoes. In the case of general cargo, it will be necessary to raise the utilization rate by remodeling a general container or improving cargo loading techniques. In the case of bulk cargo, it will be necessary to exploit the benefits of containerization in preventing product deterioration due to rain, facilitating the sale of small orders, ensuring clean cargo handling, and reducing logistics cost, among others. In the case of liquid cargo, it will be necessary to order and sell liquid cargo in small quantities by using superior quality, safe, and durable Flexitank or Flexibag products, which offer transportation convenience and reduce time and costs.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.263-268
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• 2015

Put your information in the object-based sensors and mobile networks has been developed that correlate with ubiquitous information technology as the development of IT technology. However, a security solution is to have the data stored in the server, what minimal conditions. In this paper, we propose a data management method is applied to a hash chain of the properties of the multiple techniques to the data used by the big user and the data services to ensure safe handling large amounts of data being provided in the big data services. Improves the safety of the data tied to the hash chain for the classification to classify the attributes of the data attribute information according to the type of data used for the big data services, functions and characteristics of the proposed method. Also, the distributed processing of big data by utilizing the access control information of the hash chain to connect the data attribute information to a geographically dispersed data easily accessible techniques are proposed.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.54-60
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• 2015

The autoignition temperature (AIT) of a material is the lowest temperature at which the material will spontaneously ignite. The AIT is important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs of n-decane+ethylbenzene system by using ASTM E659 apparatus. The AITs of n-decane and ethylbenzene which constituted binary system were $210^{\circ}C$ and $430^{\circ}C$, respectively. The experimental AITs of n-decane+ethylbenzene mixture were a good agreement with the calculated AITs by the proposed equations with about $11^{\circ}C$ A.A.D.(average absolute deviation).

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.8-14
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• 2015

For the safe handling of 2-methyl-1-butanol being used in various ways in the chemical industry, the flash point and the autoignition temperature(AIT) of 2-methyl-1-butanol was experimented. And, the lower explosion limit of 2-methyl-1-butanol was calculated by using the lower flash point obtained in the experiment. The flash points of 2-methyl-1-butanol by using the Setaflash and Pensky-Martens closed-cup testers measured $40^{\circ}C$ and $44^{\circ}C$, respectively. The flash points of 2-methyl-1-butanol by using the Tag and Cleveland open cup testers are measured $49^{\circ}C$ and $47^{\circ}C$. The AIT of 2-methyl-1-butanol by ASTM 659E tester was measured as $335^{\circ}C$. The lower explosion limit by the measured flash point $40^{\circ}C$ was calculated as 1.30 Vol.%. It was possible to predict lower explosion limit by using the experimental flash point or flash point in the literature.

• Journal of the Korean Institute of Gas
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• v.16 no.3
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• pp.8-15
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• 2012

For the safe handling of isopropyl alcohol, the explosion limits were investigated. The lower flash points, upper flash points, fire point, and AITs(autoignition temperatures) by ignition time delay for isopropyl alcohol were experimented. By using literature data, the lower and upper explosion limits of isopropyl alcohol were recommended as 2.0 and 12.0 vol%, respectively. The lower flash points of isopropyl alcohol were experimented $12{\sim}14^{\circ}C$ by using closed-cup tester and $18{\sim}19^{\circ}C$ by using open cup tester. And the upper flash points of isopropyl alcohol was experimented $38^{\circ}C$ by using Setaflash closed-cup tester. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 apparatus was $463^{\circ}C$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.230-239
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• 2006

The depth, width and alignment of fairway that are main port water facilities should be designed considering the various elements including particulars of design ships, weather and sea conditions around fairway and method of ship-handling. However not only the existing Japanese design standard for fairway and also those of other countries do not take into consideration of such kind of elements and no design standard is made by quantitative analysis. In this circumstance the new design standard (Approach Channels, A Guide for Design) depending on classified various elements and quantitative analysis was proposed in 1997 by PIANC and IAPH. But it was proved that calculated values according to this standard were unfounded and had some problems to output the discontinuous value by small difference of calculation condition because the each value fur each element was simply added. And also it is hard to apply this standard to the design of port water facilities in Japan because this [A Guide for Design] is the design standard for long channels in European port. The proposal of more reasonable Japanese standard will be expected by applying the study result of naval architecture and navigation and by the cooperation of ship operators to use fairway, naval architects to built ships and civil engineers to dredge fairway. The concept of a fairway in 'Design standard fur fairway in next generation' is defined as passage for approach channel) and traffic lane designated by light buoys as navigable water for safe navigation. In 'Design standard for fairway in next generation' depth, width and alignment are picked up among many design elements of a fairway. Design method for those elements is shown based on design ships and navigational environments. This standard shows the method of design for each dimension depending on characteristic on design ship and weather and sea condition. On the other hand, in case of existing fairway, it is possible to decide the size of ship and navigation criteria by opposite analysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.4
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• pp.330-336
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• 2004

To meet the increasing demand from various fishing fields for training of fishing equipment operators, a fishing winch simulator was designed to train maritime students in the correct and safe operation of hydraulic winches under various load conditions related to fishing operations. The aim of this study is to describe the basic dynamic characteristics of the newly developed hydraulic fishing winch simulator and particularly to analyze the mechanical responses produced on the winch operation controls. The winch simulator consists of two winch units, a computer control and data acquisition system, a control consol and other associated mechanisms. When one winch is in hauling mode, the other one will always be in loading mode. The revolution speed of the hauling winch was controlled by a proportional directional control valve, and the braking torque of the loading winch was controlled by a proportional pressure control valve. The simulation experiments indicated that the dynamic characteristics of the hauling winch followed the braking response characteristics of the loading winch. The tests also showed that the warp speed and tension linearly depend on the pressure differential across the motor of the loading winch controlled by operating the proportional pressure control valve during the hauling operation. The experience gained from various training courses showed that the fishing winch simulator was very realistic and it was valuable for training novice winch operators. The results of the winch simulation exercise were recorded and used to evaluate the training on the operation and handling of the winch system. From these test results, we concluded that the tension acting on the warp during hauling operations can successfully be simulated by controlling the pressure differential across the motor with step changes of the control input signal to the proportional pressure control valve of the loading winch.

• Congress of the korean instutite of fire investigation
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• 2011.04a
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• pp.102-116
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• 2011

With the spread of FMD and AI in the country livestock farmers have used lime(CaO) prevalently and due to incorrect storage lime served as a fire ignition source in a number of cases. As combined chemically with water, lime has exothermic reaction. Then In these experiments we want to know how exothermic reaction - caused by lime - acts as sources of fire ignition in any circumstances and conditions. So we have done experimental work of ignition temperature and ignition process in the artificial conditions as lime combined chemically with water. As a result, we have confirmed that lime could be flammable material sufficiently as a fire ignition source with the proper presence of heat and moisture conditions. If the lime served as sources of fire ignition, as identification techniques of fire scene, we must ascertain the existence of water, flammable material and Calcium Hydroxide($Ca(OH)_2$). We should take special precautions in order to prevent fire and educate the safe handling of lime to the manufacturer and agricultural cooperative's joint livestock farmers who product or use lime.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.292-295
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• 2004

The SIT was introduced by Nishizawa. in 1972. When compared with high-voltage, power bipolar junction transistors, SITs have several advantages as power switching devices. They have a higher input impedance than do bipolar transistors and a negative temperature coefficient for the drain current that prevents thermal runaway, thus allowing the coupling of many devices in parallel to increase the current handling capability. Furthermore, the SIT is majority carrier device with a higher inherent switching speed because of the absence of minority carrier recombination, which limits the speed of bipolar transistors. This also eliminates the stringent lifetime control requirements that are essential during the fabrication of high-speed bipolar transistors. This results in a much larger safe operating area(SOA) in comparison to bipolar transistors. In this paper, vertical SIT structures are proposed to improve their electrical characteristics including the blocking voltage. Besides, the two dimensional numerical simulations were carried out using ISE-TCAD to verify the validity of the device and examine the electrical characteristics. A trench gate region oxide power SIT device is proposed to improve forward blocking characteristics. The proposed devices have superior electrical characteristics when compared to conventional device. Consequently, the fabrication of trench oxide power SIT with superior stability and electrical characteristics is simplified.

• Safety and Health at Work
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• v.13 no.3
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• pp.357-363
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• 2022

Background: Refractory ceramic fibers (RCFs) are a suspected carcinogen but have been widely used as insulations. Depending on the temperature, RCFs can transform into crystalline SiO₂, which is a carcinogen that can be present in the air during bulk RCF handling. This study analyzed the physicochemical and morphological characteristics of RCFs at high temperatures and determined the exposure levels during the semiconductor scrubber maintenance. Methods: Sampling was conducted at a company that manufactures semiconductor scrubbers using RCFs as insulation. Bulk RCF samples were collected both before and after exposure to a scrubber temperature of 700℃. Airborne RCFs were collected during scrubber maintenance, and their characteristics were analyzed using microscopes. Results: The components of bulk RCFs were SiO₂ and Al₂O₃, having an amorphous structure. Airborne RCFs were morphologically different from bulk RCFs in size, which could negatively affect maintenance workers' health. 58% of airborne RCFs correspond to the size of thoracic and respirable fibers. RCFs did not crystallize at high temperatures. The exposure caused by airborne RCFs during the scrubber frame assembly and insulation replacement was higher than the occupational exposure limit. Conclusion: Workers conducting insulation replacement are likely exposed to airborne RCFs above safe exposure limits. As RCFs are suspected carcinogens, this exposure should be minimized through prevention and precautionary procedures.