• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.215-216
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• 2007

Isolator가 삽입된 Erbium 첨가 광섬유광원을 제작하였고 그 특성을 측정하였다. Isolator 삽입 유무에 따른 광섬유광원의 전 온도구간($-32^{\sim}75^{\circ}C$)에서의 중심파장 안정도는 수 ppm으로 큰 차이를 보이지 않았고, 귀환광 변화($-22^{\sim}-20dB$)에 따른 중심파장 안정도에서는 isolator 삽입이후에 1.6ppm으로 귀환광 변화에 매우 둔감한 결과를 얻었다.

• Journal of Korean Society for Quality Management
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• v.45 no.3
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• pp.533-547
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• 2017

Purpose: This study proposes the main sources of uncertainty and uncertainty analysis of a measurement system of insensitive munitions tests. Methods: We established the mathematical model for calculating measurement uncertainty of insensitive munitions tests, conducted experiments for calculating uncertainties of dynamic sensitivity and overshoot value, and estimated the distributions of uncertainty factors. Results: The measurement uncertainty calculation methods are presented, which include experimental data processing methods for calculating uncertainties of dynamic sensitivity and overshoot value. Conclusion: The measurement of explosion pressure in insensitive munitions tests is an important issue to the reporting test results and classifying reaction types. The more efforts to ensure the reliability of the insensitive munitions tests results are required.

• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.229-242
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• 2005

We constructed a full-text retrieval system for the scanned Hangul document images. The system consists of three parts; preprocessing, recognition, and retrieval components. The retrieval algorithm uses recognition results up to k-ranks. The algorithm is not only insensitive to the recognition errors, but also has the advantage of user-controllable recall and precision. For the objective performance evaluation, we used the scanned images of the Journal of Korea Information Science Society provided by KISTI. The system was shown to be practical through theevaluationofrecognitionandretrievalrates.

• The Korean Journal of Applied Statistics
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• v.4 no.1
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• pp.47-63
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• 1991

Parameter design is the core of the Taguchi method, and its purpose is to design product or processes such that the performance of product becomes robust to noise. Taguchi recommends to use the so called orthogonal arrays for parameter design. The purpose of this paper is to clarify the principles involved in constructing the Taguchi orthogonal arrays. Understanding such principles may be useful for finding better ways of utilizing the Taguchi orthogonal arrays as well as for developing better experimental designs.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.401-404
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• 2003

경북 고령군 다산면의 충적층 강변여과 취수에 따른 수위변화 모델링을 시도하였다. 단순화된 2가지 모델을 기본으로 하여 1일 평균 1만 5천톤의 상수도 공급 시, 일정수두 유지를 위한 연간 취수 계획 및 적정 취수량을 검토하였다. 한편, 질량 균형(mass balance)을 통하여 모델 검증 및 시기별 하천수와 지하수의 유입 비율을 예비적으로 산정하였으며, 투수계수와 함양량 변화에 따른 지하수위의 민감도를 검토하였다. 하천수 유입 비율은 시기별로 65∼85% 범위를 갖는 것으로 나타났으며, 지하수위는 함양량 변화에는 둔감한 반면, 투수계수에 대해서는 상대적으로 민감한 것으로 평가되었다.

• Science of Emotion and Sensibility
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• v.2 no.1
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• pp.69-75
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• 1999

본 연구는 우리말 형용사를 이용하여 각종 생활공간음에 대해 느끼는 사람들이 감성적 반응의 차원을 밝히기 위한 기초 연구로 수행되었다. 형용사 사전에서 추출된 어휘들에 대한 적합성 및 유사성 평가를 통해 14개의 형용사가 최종적으로 선정되었고, 이 형용사들의 유사성 점수에 대해 요인분석, 다차원 척도 분석 및 군집분석을 시행하였다. 연구 결과 생활공간음에 대한 사람들의 감성적 반응은 크게 3가지 차원, 즉 쾌-불쾌, 민감-둔감 및 지각된 크기가 추출되었고, 소음에 대해 느끼는 감성은 이들 차원 상에서 측정될 수 있는 것으로 나타났다. 이들 차원들은 서로 직선적인 관계가 있는 것으로 보인다. 즉, 소음에 대해 민감한 사람은 그 소음에 대해 불쾌하거나 짜증을 일으키기 쉽지만 소음에 대해 불쾌하거나 짜즈을 일으킨 사람이 소음에 대해 민감한 사람이라고 볼 수는 없을 것이다. 따라서 이들 차원간에 구체적인 통로분석이 이루어져야 할 것으로 보이며 이는 후속연구에서 밝혀질 것이다. 또한 실제 소음을 제시하여 각각의 소음을 평가하는 경험적 연구도 수행될 것이다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.5
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• pp.264-268
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• 1999

A new implementation strategy for the flux weakening control of a Surface Mounted Permanent Magnet Synchronous Motor (SPMSM) is proposed. It is implemented based on the output of the synchronous PI current regulator-reference voltage to PWM inverter. The onset of flux weakening and the level of the d-axis current are adjusted by the outer voltage regulation loop to prevent the saturation of the current regulator. The characteristics of this flux weakening scheme include no dependency on the machine parameters, the guarantee of current regulation on any operating condition, and fast transition into and out of the flux weakening mode. Experimental results at various operating conditions including 4-quadrant operation are presented to verify the feasibility of the proposed control scheme.

• The Korean Journal of Applied Statistics
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• v.9 no.1
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• pp.53-73
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• 1996

This paper compares two accelerated life for Weibull distribution. One is the optimum constant stress accelerated life test which minimizes the asymptotic variance of maximum likelihood estimator of a specified quantile at design stress, and the other is corresponding simple step stress test. The models and optimum designs of constant stress and step stress tests are reviewed. Behaviors of asymptotic variances, effects of design parameters to optimum tests, and expected numbers of failures and expected test times of the two tests are investigated. The efficiency of step stress test relative to constant stress test is studied in terms of variance ratio, and robustness to preestimates of design parameters are investigated.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.12
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• pp.37-42
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• 1997

A new temperature and supply-insensitive CMOS current reference circuit was designed and tested. Te temperature insensuitivity was achieved by eliminating the mobility dependence term through the multiplication of two current components, one which is proportional to mobility and the other which is inversely proportional to mobility, by using a newly designed CMOS square root circuit. The CMOS sqare root circuit was derived from its bipolar counterpart by operating the MOS transistors in the subthreshold region. The supply insensitivity was achieved by using an internal voltage generator. Te test chip was designed ans sent out for fabrication by using a 2.mu.m double-poly double-metal n-well CMOS technology. When an external voltage source was used for the square root circuit, the maximum variation and the average temperature sensitivity were measured to be 3% and 21.4ppm/.deg.C, respectively, for the temperature range of -15~130.deg.C. The maximum current variation with supply voltage was measured to be 3% within the commerical supply voltage range of 4.5~5.5V at 30.deg. C.

• Korean Journal of Optics and Photonics
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• v.8 no.3
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• pp.241-244
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• 1997

A speckle pattern from an optical fiber is used for a reference beam in writing and reading a volume hologram. The photorefractive volume hologram with this scheme shows good spatial selectivity for spatial(shift) multiplexing because the speckle pattern in writing and reading a hologram looses correlation with a small spatial shift. This scheme has the insensitivity to axial movement. The data storage system with this scheme will have a high storage density and a good stability in operation. We theoretically analyze the diffracted beam from a volume hologram recorded with the speckle pattern from the optical fiber. Experimental results are presented and compared with numerical analysis.