• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.8-12
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• 2015

Non-esterified bio-diesel fuel saves cost by no esterified process and its performance was more similar to diesel oil than esterified bio-diesel fuel when the fuel blended 95% diesel oil and 5% it was used on diesel engine with electronic control system. A performance optimization is necessary for application of non-esterified bio-diesel fuel blended with diesel oil 95% on the latest diesel engine. In this study, test using fractional factorial design was accomplished at 25% and 50% partial load in order to evaluate influence of controllable 6 factors on responses such as specific fuel consumption, nitrogen oxides and coefficiency of variation of indicated mean effective pressure as basic experiment for performance optimization of this fuel. It is cleared that the injection timing and common rail pressure of 6 factors are mainly effective and its effect level is different according to load.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.129-135
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• 2014

In the paper, we propose a design method for the logistics transportation system using magnetic levitation that has a good characteristics without mechanical friction, noise and dust. The proposed transportation system consists of a levitation control system and a propulsion control system. Magnetic levitation system is an electromagnetic suspension system in which electromagnet generates magnetic attractive force and the attractive force pulls the rail. We design a PID controller for the current control of electromagnets. We use linear induction motors for propulsion of the proposed logistics transportation system and adapt the space vector PWM method for the propulsion control system. The proposed transportation system using magnetic levitation is verified performances through levitation and propulsion experiments.

• Journal of Power Electronics
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• v.18 no.3
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• pp.931-943
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• 2018

Wireless power transfer (WPT) technology has been the focus of a lot of research due to its safety and convenience. The Z-source inverter (ZSI) was introduced into WPT systems to realize improved system performance. The ZSI regulates the dc-rail voltage in WPT systems without front-end converters and makes the inverter bridge immune to shoot-through states. However, when the WPT system is combined with a ZSI, the system parameters must be configured to prevent the ZSI from entering an "accidental shoot-through" (AST) state. This state can increase the THD and decrease system power and efficiency. This paper presents a mathematical analysis for the characteristics of a WPT system and a ZSI while addressing the causes of the AST state. To deal with this issue, the impact of the system parameters on the output are analyzed under two control algorithms and the primary compensation capacitance range is derived in detail. To validate the analysis, both simulations and experiments are carried out and the obtained results are presented.

• Journal of Korean Society for Quality Management
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• v.44 no.4
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• pp.869-881
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• 2016

Purpose: The objective of this study is to verify the economic validation of quality management integrated train freight car by analyzing economic evaluation indicators such as benefit and cost, net present value, and inter rate of return. Methods: First, we itemize benefit and cost field by reviewing literatures; Benefit consists of 1)Safety, 2)Operation, and 3)Maintenance; Cost consists of 1)Set-up fee, 2)Wireless internet fee, and 3)Cloud storage using fee. Second, based on these estimated values, we conduct an economic evaluation analysis. Among them, benefit and cost, net present value, and internal rate of return are selected. Results: As a result, all estimated values are highly over criterion of economic validity($$B/C{\geq}_-1$$, $$NPV{\geq}_-0$$, $$IRR{\geq}_-R$$); 1)benefit over cost ratio is 28.22, 2)Net present value is 8,121.66million KRW, and 3)Internal rate of return value is 2272%. Conclusion: The findings of this study will help making a decision when train industry adopts IoT technology for improving the effectiveness.

• Explosives and Blasting
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• v.11 no.4
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• pp.38-44
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• 1993

"The Japan Sea Rim Natios" Is not one that was formed under a specific idea, as in the case of the European Community, in the respect of politics, economy and culture. At present, in particular after the Cold War, Japan has extended exchange on regional and private levels with the countries located on the other side of the apan Sea from the first stages of friendship to economic relationships. In the future, it is necessary to promote the establishment of an International exchange network and traffic system for each of the traffic facilities in order to build up the Block that will mainly contribute to the economies of countries and regions In the area. For the purpose, it is fundamental to reexamine the national land planning and the local development planning of each of the countries. From the standpoint of technology, the issues to be looked into are : study and development on marine civil engineering such as structures over straits study and development on the construction engineering of express ways and exprees rail roads : development of vehicles such as cars and trains I propose approaches to my vision of these traffic systems from my standpoint as an engineer in this paper.his paper.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.88-96
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• 2008

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. This study used a split injection method at a 4 cylinder common-rail direct injection diesel engine in order to apply the partially premixed charge compression ignition combustion method without significantly altering engine specifications And it is investigated that the effects of the injection ratio and SCV(swirl control valve) to emission characteristics. From these tests, soot(g) and NOx(g) emission could be reduced to 40% and 92% compared to base engine performance at specified engine driving conditions(6 points with weight factors) according to application of split injection and SCV(swirl control valve).

• Nuclear Engineering and Technology
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• v.14 no.4
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• pp.196-203
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• 1982

To transport the spent fuel assemblies of Korea Nuclear Unit 1, which is a Westinghouse type two loop pressurized water reactor, it has been found that steel is the most appropriate material for the design of a shipping cask in comparison with lead and depleted uranium. The proposed shipping cask will transport nine fuel assemblies at the same time and is well within the weight limit of transportation by unrestricted rail car. The cask requires 33cm thick steel shield and 27cm thick water region to satisfy the 3 feet apart dose rate limit set forth in 10 CFR 71, and 1.27cm thick steel boron fuel basket to hold the fuel elements inside the cask and control the effective multiplication factor. As a safety analysis, the fuel cladding and centerline temperatures were calculated under the accident condition of complete loss of water coolant, and it was found that the temperature was much lower than the limit of the melting point. k$_{eff}$ was calculated with fresh fuel assemblies, which was found to be well lower than 0.95. For shielding computation, the multipurpose Monte Carlo code MORSE-CG and one dimensional discrete ordinates transport code ANISN were used, and the Monte Carlo codes KENO and MORSE-CG were used for criticality calculation. The radiation source terms were calculated using ORIGEN-79.9.

• Proceedings of the Korean Professional Engineer Association Conference
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• 1992.12a
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• pp.143-150
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• 1992

“The Japan Sea Rim Nations” is not one that was formed under a specific idea, as in the case of the European Community, in the respect of politics, economy and culture. At present, in particular after the Cold War, Japan has extended exchange on regional and private levels with the countries located on the other side of the Japan Sea from the first stages of friendship to economic relationships. In the future, it is necessary to promote the establishment of an international exchange network and traffic system for each of the traffic facilities in order to build up the Block that will mainly contribute to the economies of countries and regions in the area. For that purpose, it Is fundamental to reexamine the national land planning and the local development planning of each of the countries. From the standpoint of technology, the issues to be looked into are : study and development on marine civil engineering such as structures over straits : study and development on the construction engineering of express ways and express rail roads : development of vehiclessuch as cars and trains ; I propose approaches to my vision of these traffic systems from my standpoint as an engineer in this paper.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.197-204
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• 2005

Multipurpose Floor Level Joint(MFLJ) is a new construction technology system which was developed in domestic. By using this system, it is possible not only to absorb the deformation at expansion joint due to shrinkages of concrete but also to make ease the floor leveling during the concrete casting at floor. The system consists of two elements, supporting devices and rails. Their structural capacities were verified through several experimental programs, such as compressive strength test of support and bending test of rail. The purpose of this paper is to evaluate the deformation absorbing capacity of the floor level joint. An experimental work was carried out to simulate the deformation condition at the joint and the test result was analyzed and evaluated. In addition, FEM analysis for expansion joint of typical building was also performed to predict the real behavior of MFLJ. The test results showed that MFLJ has sufficient deformation capacity required to act as expansion joint.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.555-560
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• 2003

Korean High Speed Train(KHST) has been tested on the high speed test line in Osung site of Korea High Speed Rail Construction Authority (KHRC). since it was developed as G7 Project Plan In 2002. This paper introduces the dynamic test devices in KHST and shows the comparison between the results of test and theoretical computing results which derive from the new model for KHST dynamic behavior. Previous computer simulation model for KHST was developed to review wether the vehicle system was satisfied with the dynamic performance requirements during the design procedure. But It should be applied the results of the parts test for suspension elements in order to compare between the results of computation and real test. Using VAMPIRE Program made by AEA Technology in UK. the new model also was modified. This paper shows that the static wheel loads calculated from new model is similar to test results. For test on high speed line, we prepared the test devices for evaluating the dynamic performances. which was consisted of the accelerometers( based on Kisler Co.) and the data aquisition systems (based on National instrument Co.), and test program coded by LabView 6i program. These lest devices and programs are flexible to extension the channels for adding sensors and connect to the ethernet network. The acceleration of car bodies, bogie frames and axle boxes were compared between the results of computation and test at 150km/. This paper shows that the results of test were high in high frequency band range but similar frequency band range. It might be considered that these differences were caused by the test which did not performed at constant speed for comparison analysis. Also. It will be able to understand the differences and make better results through a lot of tests planed in future.