• International Journal of Precision Engineering and Manufacturing
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• v.1 no.2
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• pp.14-23
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• 2000

A numerical scheme is proposed to obtain the individual stress intensity factors in an axisymmetric crack and in a three dimensional mixed mode crack. The method is based on the path independence of J and M integral and mutual or two-state conservation integral , which involves two elastic fields. Some numerical example are presented to investigate the effectiveness and applicability of the method for and axisymmetric crack and a three dimensional penny shaped crack problem under mixed mode.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.198-201
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• 2004

In this paper, the discrete optimal control is made to have the robust property of Sliding mode controller. A augmented system with a virtual state is constructed for this objective and noble sliding surface is constructed based on this system. The sliding surface is the same as the optimal control trajectory in the original system. The states follow the optimal trajectory even if there exist uncertainties. The reaching phase problem of sliding mode control is disappear in this method.

• Nuclear Engineering and Technology
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• v.35 no.4
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• pp.347-355
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• 2003

The \gamma-ray spectrometer of the PGAA (Prompt Gamma Activation Analysis) facility constructed at HANARO of the Korea Atomic Energy Research Institute was upgraded to the multi-mode spectrometer including the single mode, the Compton suppression mode and the pair mode. The performance of the spectrometer was tested and summarized. The background count rate and the uncertainty of the detection efficiency were reduced greatly in comparison with those before the new installation.

• Korean Journal of Optics and Photonics
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• v.15 no.1
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• pp.22-27
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• 2004

In this paper, we designed a mode size converter to reduce coupling loss between optical waveguide and single mode fiber. The proposed mode converter is composed of periodically segmented tapered waveguide to achieve small size and easy fabrication. For the optimally designed mode size converter at 1550nm, the taper length is 500(equation omitted), the segmentation period 5ß:, the waveguide width of fiber contact section 1.3ß:, and duty cycle 0.95. The coupling loss of the optimized mode size converter is 0.33㏈/point, which is 1.27㏈/point lower than that without the mode size converter.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.83-90
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• 2004

In this paper, we proposed a new instruction set(X32Y ISA) with 3 different types of instruction mode. The proposed instruction set organizes 32-bit, 24-bit, 16-bit instruction in order to solves a problem of memory size limitation in an embedded microprocessor. We designed a 32-bit 5 stage pipeline RISC microprocessor based on the X32V ISA. To verify the proposed the X32V ISA and a microprocessor, we estimated a program code size of multimedia application programs using a X32V simulator. In result, we verified that the Light mode and the Ultra Light mode obtains 8%, 27% reduction of a program code size through comparison with the Default mode. The proposed microprocessor was verified all X32V instructions execution at Xilinx FPGA with 33MHz operating frequency,

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.208-212
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• 2003

An airborne radar is an essential aviation electronic system of the helicopter to perform various missions in all-weather environments. This paper presents the conceptual design results of the multi-mode pulsed Doppler radar system testbed model for helicopter. Due to the inherent flight nature of the hovering vehicle which is flying in low-altitude and low speed, as well as rapid maneuvering, the moving clutters from the platform should be suppressed by using a special MTD (Moving Target Detector) processing. For the multi-mode radar system model design, the flight parameters of the moving helicopter platform were assumed: altitude of 3 Km, average cruising velocity of 150knots. The multi-mode operation capability was applied such as short-range, medium-range, and long-range depending on the mission of the vehicle. The nominal detection ranges is 30 Km for the testbed experimental model, but can be expanded up to 75 Km for the long range weather mode. The detection probability of each mode is also compared in terms of the signal-to noise ratio of each mode, and the designed radar system specifications ate provided as a design results.

• Journal of Technology Innovation
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• v.10 no.1
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• pp.148-173
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• 2002

This study examines the impact of the Internet on the organizational innovation. With the introduction of digital technology, the entire organizational process and structure is now being restructured. The purpose of this study is to develop a framework to help classify the organizational innovations and understand organizational innovation processes. This study suggests that the wide diffusion of digital technology has affected the modularization of the organizational routines and processes. The modularization of knowledge and organization give rise to a new organizational architecture, a modular architecture. In the Fordist regime, the characteristics of organizations were depicted as vertically integrated and tightly coupled system. The organizational processes and routines were tightly linked and integrated. However, the diffusion of Internet, which has a tendency to disassemble this tightly coupled system, has resulted in the emergence of loosely coupled and vertically disintegrated system. Eventually the modular architectures are emerging as a new organizational paradigm in the post-Fordist regime. In this study, the modes of organizational innovation is classified as follows. If the organizational innovation enhances both existing organizational components and tile tightly coupled architecture, it is incremental innovation (Mode 1): if it destroys both existing components and the tightly coupled architecture, it is radical innovation (Mode 4): however if only the tightly coupled architecture is transformed into the modular architecture and the codification of organizational component is enhanced, the innovation is architectural (Mode 3). The last one is component innovation (Mode 2), in which existing organizational components are destroyed but tightly coupled architecture is enhanced. It is argued that the organizational innovation process follows Mode I$\longrightarrow$ Mode II $\longrightarrow$ Mode III $\longrightarrow$ Mode IV in order.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.1
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• pp.33-39
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• 2011

This paper considers a performance analysis of set-top box (STB) power saving schemes. STB converts the signal into content which is then displayed on the television (TV) screen, and there are typically two operation modes: on mode and stand-by mode. The total energy consumption (TEC), a typical measure of power consumption of STB, is defined by the sum of power consumption in each mode. Recently there are some works of STB power saving schemes that transit STB operation modes efficiently, and the mode transition time point of those schemes can be different. Thus it is required to develop a performance evaluation method that reflects mode transition time points of each scheme to get TEC correctly. This paper proposes a performance evaluation method for STB power consumption using Poisson process to consider the mode transition time point. By modeling STB mode transitions as events of Poisson process, the average time duration of STB mode is computed and accordingly the effect of power saving is evaluated. The performance evaluation result shows that the proposed method achieves 1 to 19% improvement in power consumption compared with a conventional performance evaluation method.

• Computational Structural Engineering
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• v.9 no.2
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• pp.115-120
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• 1996

The main concern of numerical dynamic analysis of large structures is to find an acceptable solution with fewer mode shapes and less computational efforts. Component mode method utilizes substructure technique to reduce the degree of freedom but have a disadvantage to not consider the dynamic characteristics of loads. Ritz Vector method consider the load characteristics but requires many integrations and errors are accumulated. In this study, to improve the effectiveness of component mode method, Lanczos algorithm is introduced. To prove the effectiveness of this method, example structure are analyzed and the results are compared with SAP90.

• Korean Journal of Optics and Photonics
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• v.32 no.2
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• pp.55-61
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• 2021

The lateral-mode characteristics of 850-nm GaAs/(Al,Ga)As multiple-quantum-well laser diodes and their influence on the kinks in output optical power are investigated. For the investigation, self-consistent electro-thermal-optical simulation and measurement of fabricated devices are used. From this investigation, the optimal P-cladding thickness that provides single-lateral-mode operation is determined, so that high beam quality can be achieved even at high output powers.