• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.365-373
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• 2017

This study proposes a newly developed dry washing method for removing pollutants such as total petroleum hydrocarbon (TPH) and oxidized iron from the surface of ballast gravel. A batch-type dry washing method showed a good performance in a previous study. In this study, a continuous-type dry washing system, instead of a batch-type system, was prepared to improve the efficiency of the system. A drier and a separator were also applied to this system as pre-treatment process, and the performance of this system was evaluated. In this experiment, blasting media was blasted on the polluted gravels through 12 nozzles by a pressure of $5-6kg/cm^2$ for 20-30 mins to remove TPH and oxidized iron. It was found to be possible to remove 80-90% of TPH and oxidized iron by using this system. Several ways to improve the performance were suggested in this study.

• Cross-Cultural Studies
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• v.51
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• pp.329-356
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• 2018

Types of emotional expressions are comprised of vocabulary that describes emotion and composition of sentences to express emotion such as an exclamatory sentence and a rhetorical question, expressions of interjection, adverbs of attitude for an idea, and a style of writing. This study is focused on vocabulary that describes emotion and analyzes the aspect of translation when emotional expression of 'Kyo(驚)' is shown in "Kokoro". As a result, the aspect of translation for expression of 'Kyo(驚)' showed that it was translated to vocabulary as suggested in the dictionary in some cases. However, it was not always translated as suggested in the dictionary. Vocabulary that describes the emotion of 'Kyo(驚)' in Japanese sentences is mostly translated to corresponding parts of speech in Korean. Some adverbs needed to add 'verbs' when they were translated. Different vocabulary was added or used to maximize emotion. However, the corresponding part of speech in English was different from Korean. Examples of Japanese sentences expressing 'Kyo(驚)' by verbs were translated to expression of participles for passive verbs such as 'surprise' 'astonish' 'amaze' 'shock' 'frighten' 'stun' in many cases. Idioms were also translated with focus on the function of sentences rather than the form of sentences. Those expressed in adverbs did not accompany verbs of 'Kyo(驚)'. They were translated to expression of participles for passive verbs and adjectives such as 'surprise' 'astonish' 'amaze' 'shock' 'frighten' 'stun' in many cases. Main agents of emotion were showat the first person and the third person in simple sentences. Translation of emotional expressions when a main agent was the first person showed that the fundamental word order of Japanese was translated as in Korean. However, adverbs of time and adverbs of degree were ended to be added. The first person as the main agent of emotion was positioned at the place of subject when it was translated in English. However, things or causes of events were positioned at the place of subject in some cases to show the degree of 'Kyo(驚)' which the main agent experienced. The expression of conjecture and supposition or a certain visual and auditory basis was added to translate the expression of emotion when the main agent of emotion was the third person. Simple sentences without the main agent of emotion showed that their subjects could be omitted even if they were essential components because they could be known through context in Korean. These omitted subjects were found and translated in English. Those subjects were not necessarily human who was the main agent of emotion. They could be things or causes of events that specified the expression of emotion.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.65-72
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• 2014

Turbine rotor-pyrostarter coupled test was performed for the verification of thermo-structural suitability of a turbopump turbine. Newly developed solid propellant and design concept were used in pyrostarter development. In case of turbine rotor, rotor configuration modification and post EDM machining process are adopted in rotor manufacturing respectively for the thermal stress relief and the surface integrity improvement on the blade surfaces. In the test, combustion gas of pyrostarter was directly ejected from the nozzles and impinged on the stationary turbine rotor specimen through the identically shaped flow passage of turbopump. Three kind of thermal load - design to extreme condition - test were performed and no damages were found on the turbine rotor specimens.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.23-28
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• 2012

The LPG engine technology in Korea has made significant advances with the mass production of LPG vehicle with liquid phase LPG injection system, and have reached to satisfy the SULEV emission regulations. As of now, domestic production of LPG fuelled vehicles in Korea have reached more than 2.4 millions, which is the best in the world. But in the technical point of view, the key technologies for fuel injection system of LPG fuelled engine are mainly dependent on foreign license. Especially, fuel injector in the liquid phase LPG injection system has been imported from C company, which supplies LPG injector worldwide in the name of model D. In the context, it is quite urgent to develop the LPG injector technology in Korea. In this study, WCC coating which is key technology to develop LPG injector by reducing the fuel leakage was developed and tested. Considering the fuel leakage of 0.06cc/min in commercial LPG injector, fuel leakage was reduced down to 0.04cc/min with WCC coating technology and optimization of injector structure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.199-204
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• 2020

In case of the silicon solar panel being used in Korea, the production specification is designed to give maximum output at the limit of -0.5 to 0.05℃, so the output of 0.45~0.55% decreases when the temperature rises by 1℃. As a result, the photovoltaic power generation is reduced according to the surface temperature rise of the photovoltaic module due to the characteristics of the solar cell. The decrease in output reduces the efficiency of photovoltaic power generation, and if the efficiency decreases, the result is that the profit of electricity sales according to the amount of photovoltaic power generation decreases. Therefore, this paper proposes a method of spraying cooling air to the lower (or surrounding) of the photovoltaic module when it is identified above the set temperature by the temperature detection sensor. In addition, the amount of power generated is increased by utilizing the lost solar energy, and by applying cooling function through cooling air, the power generation can be further increased.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.128-133
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• 2005

In this study, performance design programs for components of a turbopump unit (TPU) in a Liquid Rocket Engine (LRE), that has non-cryogenic centrifugal pumps and 1-stage impulse turbine with partial admission nozzle, were developed. The programs were integrated in a TPU module by balancing the mass flow rate for pump-turbine power, and the module was inserted into the LRE system conceptual design program. The fundamental design conditions, satisfying LRE system requirements and minimum mass flow rate condition of gasgenerator, were found and compared with data from a Russian liquid rocket engine.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.297-308
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• 2007

The granulation equipment of concentrated wastes is manufactured for the polymer solidification of concentrated wastes. It uses liquid sodium silicate as a granulating agent for the granulating of dried powder containing boric acid. The granulating agent is sprayed in the form of droplet and mean size of dried granules is $2{\sim}4mm$. The new technology which has been used for the polymer solidification of spent resin in U.S. and certified by Nuclear Regulatory Commission (NRC) is successfully applied to concentrated wastes. This uses in-situ solidification process within drum without mechanical mixing. Maximum loading of waste can be achieved without increasing of waste volume. Polymer waste forms were evaluated with several test such as fire test, compressive strength test, leaching test, immersion test, irradiation test, and thermal cycling test according to standard test procedures.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.8
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• pp.47-53
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• 2004

An Experimental investigation into the effects of the blowing jet type and jet orientation on the aerodynamic characteristics over an elliptic type airfoil is explored. This study is aimed at expanding the data base of blowing jet application in separation control of elliptic airfoil. Present data includes: surface pressure, blowing jet exit velocity measurements and integrated aerodynamic loads. The experiments were performed for an elliptic airfoil at Reynolds number $8.22{\times}10^5$. The improvement of effects of pulsed jet on the increase of aerodynamic characteristics was significant for the post-stall angle. For reduced mass flow rates, pulsed jet allowed considerably higher lift to be generated. The jet orientation also showed dominant parameter on the separation control Positive jet angle delay or avoid separation, whereas negative jet angle promotes it.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.95-102
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• 2011

Anti-icing system can immediately respond when snowing is expected or the snow comes down on the road surface. It has been recognized that the system can reduce traffic accidents and congestion by quickly removing the frozen road surface area. However, it is very difficult to implement this system due to the expensive equipment installation and operation cost, Recently, there was a developed program for predicting the freezing area using three-dimensional model and tracking the sun path. But, there is no objective analysis method and all developed approaches are different so that the general standard of anti-icing system is needed. In this study, we proposed the decision criteria for determining application priorities of the anti-icing system based on weather and road conditions, i.e., geometric and topographic conditions. Regional climate survey, topographical analysis, and dynamic vehicle simulation considered road geometry and skid resistance was conducted to standardize the installation method of anti-icing system.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.566-575
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• 2011

Since LPG (Liquefied petroleum gas) fuel supply system has an advantage of low emission characteristics, many studies have been conducted. In spite of the advantage of LPG supply system, a higher vapor pressure and lower viscosity than diesel or gasoline fuel may cause unstable running of fuel pump by the deterioration in lubrication performance and chemical reaction with rubber parts than that of diesel and gasoline fuel. Therefore its physical properties can cause the deterioration of durability. In this research, we developed an external type LPG pump which has the advantage of the price competitiveness and the convenient maintenance for LPLi system. The experiments were carried out in order to assess characteristics of the external type fuel pump at different fuel composition and temperature. As a result, there aren't any differences between internal and external type pump performance. It is observed that the same level of efficiency was maintained for both pumps as flow rate was increased with higher fuel temperature and more contents of propane in the fuel. And the pressure difference in LPLi system is maintained at constant with the various fuel compositions and temperatures due to their own characteristics of fuel supply system.