• Journal of the Society of Naval Architects of Korea
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• v.34 no.3
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• pp.70-75
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• 1997

This paper concerns with a safe and efficient transportation method of hot-coils on cargo ship. An automatic loading and unloading system of hot-coils by cassettes, which secure the geometrically unstable cargo, hot-coil, by supporting with wedges on both sides, is considered efficient and profitable. Safety of hot-coil on cassette and subsequently safety of total cargo ship are directly affected by the wedge angle of cassette. For optimal design of the cassette wedge angle, a dynamic model of hot-coil/cassette cargo is developed with constraint of no relative motions between the coil and the cassette. Force equilibrium conditions between resultant alternating inertia forces on hot-coil due to motions of cargo ship in waves and reactions forces from cassette wedge surfaces are derived and consequently a numerical simulation code is implemented. Cassette wedge angle of 37 degree is taken as optimal by considering dynamic stability of hot-coil and strength of cassette structure. Performance of the designed cassette wedge angle is investigated by scaled bench test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2385-2390
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• 2015

In the beginning run, urban railway had been required as transportation. But now days urban railway have stayed in the platform for long time, the platform is faced the problem that is improvement of environment as one of the living space. Thus, sliding automatic door on the basis of screen door have used in huge distribution market, hospital, restaurant and public office because it is comfortable that customer's convenience and entrance are controled. So screen door not only requires customer's convenience and safe, clean area and energy conservation but demands optimal design technology development of screen door system that is confirmed by element parts of design and confidence. In this paper, For secure confidence of screen door, after as modeling roller and frame's system, confirming the result for qualification of driving stiffness. And then it suggests that it is possible to increase performance and declines fraction defective of element's part.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2808-2814
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• 2012

The most of military systems that developed today are composed with many sub-systems for mission execution. The test of military systems for delivery test of mass product such that part test, PCB test, component test, integration test. Improving productivity is minimize testing item by man and minimize kind of tester, so that decrease product cost by production time for test. PCB tester be developed many kind of test method that systems were developed by many different engineers. This article studies testing check point for testing that how to minimize of kind of tester, how to automatic test for all of function that have inputs and outputs. Development of tester for improving productivity requires classify functional allocation of main system and sub system, sub system require PCB for functional allocation start on preliminary design period for reducing testing item and testing fixture.

• Journal of Internet Computing and Services
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• v.8 no.6
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• pp.75-85
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• 2007

One of important factors for improving the learning achievement of students in computer programming education is to provide plenty of opportunities of problem-solving experiences through variety forms of assignments, However, for the most cases, evaluation of programming assignments is performed manually by instructors and automated tools for the accurate evaluation are not equipped at the present time. Under this restricted environment instructors need much work and time to grade assignments so that instructors could not deliver sufficient programming assignments to students, In order to overcome this problem. au automated programming assignment evaluation system is needed that would enable instructors to evaluate assignments easily in an effective and consistent way and also to detect any plagiarism activities among students in program source codes readily, Accordingly, in this paper we design and implement a Web-based programming assignment grading system that allows instructors to evaluate program performance automatically as well as to evaluate program styles and piagiarism easily with appropriate feedback.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.35-43
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• 2006

An MPI Checkpointer is a tool which provides fault-tolerance through checkpointing The previous researches related to the MPI checkpointer have focused on automatic checkpointing and recovery capabilities, but they haven't considered portability issues. In this paper, we discuss design and implementation issues considered for portability when we developed an MPI checkpointer called STFT. In order to increase portability, firstly STFT supports the abstraction interface for a single process checkpointer. Secondly, STFT uses a user-based checkpointing method, and limits possible checkpointing places a user can make. Thirdly, STFT lets the MPI_Init create network connections to the other MPI processes in a fixed order. With these features, we expect STFT can be easily adaptable to various platforms and MPI implementations, and confirmed STFT is easily adaptable to LAM and MPICH/P4 with the prototype Implementation.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.501-506
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• 2001

The Korean government established a domestic specification system, and regulated that owner should produced construction project specifications, instead of special provisions, in design phase, January 1998. But in Korea the ability of construction engineers for construction project specification are insufficient. So the government had built up a database of standard specifications and developed a supporting system for writing construction project specification(SPECMAKE) in 1999. However, it is a PC base stand-alone system, so it is not convenient to update the database. In order to overcome these limitations, the purpose of this paper builds up a database of construction criteria and develops a automatic writing system for construction project specification on web base. The database contains standard specifications, design and construction guidelines related with construction business. And this paper describes the frameworks, the components, and the functions of the specifications writing system for the construction projects.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2471-2478
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• 2020

Pumps are essential machinery in the various industries. With the development of high-speed and large-scale pumps, especially high energy density, high requirements have been imposed on the vibration and noise performance of pumps, and cavitation is an important source of vibration and noise excitation in pumps, so it is necessary to improve pumps cavitation performance. The modern pump optimization design method mainly adopts parameterization and artificial intelligence coupling optimization, which requires direct correlation between geometric parameters and pump performance. The existing cavitation performance calculation method is difficult to be integrated into multi-objective automatic coupling optimization. Therefore, a fast prediction method for pump cavitation performance is urgently needed. This paper proposes a novel cavitation prediction method based on impeller pressure isosurface at single-phase media. When the cavitation occurs, the area of pressure isosurface S_iso increases linearly with the NPSH_a decrease. This demonstrates that with the development of cavitation, the variation law of the head with the NPSH_a and the variation law of the head with the area of pressure isosurface are consistent. Therefore, the area of pressure isosurface S_iso can be used to predict cavitation performance. For a certain impeller blade, since the area ratio R_s is proportional to the area of pressure isosurface S_iso, the cavitation performance can be predicted by the R_s. In this paper, a new cavitation performance prediction method is proposed, and the feasibility of this method is demonstrated in combination with experiments, which will greatly accelerate the pump hydraulic optimization design.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.336-343
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• 1995

The Self Tuning Regulator(STR) method which is an approach of adaptive control theory, is ap-plied to design the fully automatic power controller of the nonlinear reactor model. The adaptive control represent a proper approach to design the suboptimal controller for nonlinear, time-varying stochastic systems. The control system is based on a third­order linear model with unknown, time-varying parameters. The updating of the parameter estimates is achieved by the recursive extended least square method with a variable forgetting factor. Based on the estimated parameters, the output (average coolant temperature) is predicted one-step ahead. And then, a weighted one-step ahead controller is designed so that the difference between the output and the desired output is minimized and the variation of the control rod position is small. Also, an integral action is added in order to remove the steady­state error. A nonlinear M plant model was used to simulate the proposed controller of reactor power which covers a wide operating range. From the simulation result, the performances of this controller for ramp input (increase or decrease) are proved to be successful. However, for step input this controller leaves something to be desired.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.55-66
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• 2017

Korean small and medium sized software companies have tried to export their solutions or services to overseas markets. In 2016, exports of the software industry increased by 6.0% from the previous year, and the value added of the industry was 2.2 times higher than that of the manufacturing industry. From a long-term perspective, it is important to secure a global competitive advantage in order to sustain the export high value-added of the software industry. The obstacles to entry into the overseas market of small to medium enterprises are as follows: first, difficulty in product development and localization of marketing; second, lack of investment for overseas expansion; and finally, competitiveness of software technology. In particular, To overcome such obstacles, Korean small and medium sized software companies should increase the technical perfection and secure software export competitiveness. The paper presents a payment settlement framework enabling adaptive reuse and semiautomatic development of global payment settlement services. The quantitative and qualitative evaluation results are presented with domestic and overseas case studies as follows: Firstly, semi-automatic development is realized successfully by applying the framework. Secondly, it is possible to maintain consistent quality of software and to deliver maintenance services without relying on the internal human resources. Thirdly, it is possible to reduce the project duration of the same development cope to less than 50% by applying the framework. Finally, because it is based on BPMN 2.0, which is a high level design diagram, it is expected that it will be easy to implement through components connection and reduce difficulties in technology transfer and localization. Also, at the time of runtime operation, it will be effective to understand the design idea easily and to carry out additional developments without human resource who participated in the initial project.

• Wind and Structures
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• v.30 no.4
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• pp.339-366
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• 2020

This study aims at modeling boundary layers (BLs) encountered in sparse and built environments (i.e. open, suburban and urban) at the subsonic Wind Tunnel (WT) at Ryerson University (RU). This WT has an insignificant turbulence intensity and requires a flow-conditioning system consisting of turbulence generating elements (i.e., spires, roughness blocks, barriers) to achieve proper turbulent characteristics. This system was developed and validated in the current study in three phases. In phase I, several Computational Fluid Dynamic (CFD) simulations of the tunnel with generating elements were conducted to understand the effect of each element on the flow. This led to a preliminary design of the system, in which horizontal barriers (slats) are added to the spires to introduce turbulence at higher levels of the tunnel. This design was revisited in phase II, to specify slat dimensions leading to target BLs encountered by tall buildings. It was found that rougher BLs require deeper slats and, therefore, two-layer slats (one fixed and one movable) were implemented to provide the required range of slat depth to model most BLs. This system only involves slat movement to change the BL, which is very useful for automatic wind tunnel testing of tall buildings. The system was validated in phase III by conducting experimental wind tunnel testingof the system and comparing the resulting flow field with the target BL fields considering two length scales typically used for wind tunnel testing. A very good match was obtained for all wind field characteristics which confirms accuracy of the system.