• Journal of KIISE:Software and Applications
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• v.36 no.3
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• pp.244-251
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• 2009

We present a transformation which converts open-code multi-staged programs into closed ones. Staged computation, which explicitly divides a computation into separate stages, is a unifying framework for existing program generation systems. Because a multi-staged program generates another program, which can also generate a third program and on, the implementation of a multi-staged language is not straightforward. Dynamic binding of (lexically free) variables in code also makes the implementation of a multi-staged language hard. By converting each code into code of function which takes environment for free variables as its argument and giving an actual environment at the code-composition site, we can transform a open-code program into a closed-code one. Combining with Davies and Pfenning's method, our closed-code-conversion enables the implementation of the unstaged language to be useful for executing multi-staged programs. We also prove the correctness of our conversion: the converted program is equivalent to the original program, and the converted program does not have open code.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06a
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• pp.294-295
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• 2007

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.466-469
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• 2011

단계가 없는 고차원 프로그램(higher-order program)을 다단계 프로그램(multi-staged program)으로 타입의 도움을 받아 변환하는 방법을 제시한다. 이 방법은 최첨단의 다단계 프로그램 타입시스템에 기반했기에 직관적으로 이해가 쉽고, 열린 코드(open code)를 지원한다. 변환의 결과 나올 수 있는 열린 코드는 자유 변수(free variable)을 허용하여 나중에 사용자의 의도대로 자유롭게 묶이게 할 수 있다. 우리의 변환은 기존의 타입의 도움을 받아 특화시키는 Linger와 Sheard[2,3]의 방법에 비해 더 효율적이고, 더 많은 종류의 다단계 프로그램을 만들어 낼 수 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.2
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• pp.67-74
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• 2002

The paper deals with a fully assumed strain soild element that can be used for modeling of thin sensors and actuators. To solve fully coupled field problems, the eledtric potential is regarded as a nodal degree of freedom in addition to three translations in an eighteen node assumed strain soild element. Therefore, the induced electric potential can be calculated for a prescribed load and the actuation displacement can be computed for an input voltage. Since the assumed strain solid element can alleviate locking. A finite element code is developed based on the formulation and typical numerical examples are solved for code validation. Using the code, we have conducted parametric study for THUNDER actuator. It is found that a particular combination of materials for layer curvature of THUNDER improves the actuation displacement.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.831-840
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• 2019

Flush Air Data Sensing system (FADS) estimates air data states using pressure data measured at the surface of flight vehicles. The FADS system does not require intrusive probes, so it is suitable for high performance aircrafts, stealth vehicles, and hypersonic flight vehicles. In this study, calibration procedures and solution algorithms of the FADS for a sphere-cone shape vehicle are presented for the prediction of air data from subsonic to supersonic flights. Five flush pressure ports are arranged on the surface of nose section in order to measure surface pressure data. The algorithm selects the concept of separation for the prediction of flow angles and the prediction of pressure related variables, and it uses the pressure model which combines the potential flow solution for a subsonic flow with the modified Newtonian flow theory for a hypersonic flow. The CFD code which solves Euler equations is developed and used for the construction of calibration pressure data in the Mach number range of 0.5~3.0. Tests are conducted with various flight conditions for flight Mach numbers in the range of 0.6~3.0 and flow angles in the range of -10°~+10°. Air data such as angle of attack, angle of sideslip, Mach number, and freestream static pressure are predicted and their accuracies are analyzed by comparing predicted data with reference data.