• Title/Summary/Keyword: CROW

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A Study on Reliability Program of the Armed Vehicles (기동/화력 장비 신뢰도 성장모형 적용 사례)

  • Lee, Chang Hee;Ku, Yung Seo;Hong, Hyun Eni;Jung, Il Ho;Park, Du Il;Kim, Sang Boo
    • Journal of Korean Society for Quality Management
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    • v.44 no.3
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    • pp.565-574
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    • 2016
  • Purpose: In this study, A reliability assurance model (or reliability program) is proposed to evaluate the reliability of an armed vehicle. The reliability assurance is performed through the reliability-centered activities in the K-000(armed vehicle) of D-Company Methods: By reflecting the current situations of korea defense industry, a reliability assurance model is built up based on the benchmarking results of world leading companies' best practices in same fields. So The reliability growth model is applied the Crow-AMSAA model Results: This research analysis the K-000(armed vehicle) of D-Company using the DT and OT failure data. and application case study by growth model of armed vehicles Conclusion: This research is result of application case study by growth model of armed vehicles.

A Study on the Plannig Characteristics of Crow Island Elementary School (크로우 아일랜드 초등학교의 계획특성에 관한 연구)

  • Lee, Jung-Woo
    • Proceedings of the KAIS Fall Conference
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    • 2012.05b
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    • pp.852-855
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    • 2012
  • 크로우 아일랜드 초등학교는 미국 근대교육 및 학교 건축사에서 기념비적 위치를 차지하고 있다. 1940년 건립된 이래 현재까지도 초등학교로서 그 기능을 유지하고 있으며 진보적인 교육철학이 학교 건축으로 구체화된 사례로 학교건축의 원론적 가치들은 시대의 흐름에도 불구하고 유효함을 웅변해 주고 있다. 본 연구는 이러한 크로우 아일랜드 초등학교의 계획 특성을 자기 수용형 단위교실의 구성, 아동중심공간의 실천, 통합디자인의 적용이라는 측면에서 살펴보고 그 의미를 고찰하였다.

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The Bayesian Analysis for Software Reliability Models Based on NHPP (비동질적 포아송과정을 사용한 소프트웨어 신뢰 성장모형에 대한 베이지안 신뢰성 분석에 관한 연구)

  • Lee, Sang-Sik;Kim, Hee-Cheul;Kim, Yong-Jae
    • The KIPS Transactions:PartD
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    • v.10D no.5
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    • pp.805-812
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    • 2003
  • This paper presents a stochastic model for the software failure phenomenon based on a nonhomogeneous Poisson process (NHPP) and performs Bayesian inference using prior information. The failure process is analyzed to develop a suitable mean value function for the NHPP; expressions are given for several performance measure. The parametric inferences of the model using Logarithmic Poisson model, Crow model and Rayleigh model is discussed. Bayesian computation and model selection using the sum of squared errors. The numerical results of this models are applied to real software failure data. Tools of parameter inference was used method of Gibbs sampling and Metropolis algorithm. The numerical example by T1 data (Musa) was illustrated.

The Efficacy of Ampule Containing Herbal Extract for Improving Skin Wrinkles in Women (한약재 추출물 함유 앰플의 주름개선 효능에 관한 기초 임상연구)

  • Do, Eun-Ju;Lee, Jin-Sang;Park, Hyun-Jin;Ha, Il-Do;Kim, Young-Chul;Kim, Mi-Ryeo
    • Herbal Formula Science
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    • v.17 no.2
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    • pp.111-121
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    • 2009
  • Objectives : This study was performed to evaluate the efficacy of ampule containing herbal extract(Ulmus davidiana, Ginkgo biloba, Perilla ocymoides, Morus alba, Glycyrrhiza uralensis (licorice), and Angelica gigas) on skin wrinkles in adult women with facial wrinkles. Methods : A total of 12 women, 30 to 46 years of age, with wrinkles in the corner of eyes, applied ampule containing herbal extract twice daily for up to 12 weeks. Silicon replicas of right crow's feet area and antecubital fossa were taken before use of test product and at 4, 8 and 12 weeks. The replicas were analyzed by optical profilometry with Skin Visiometer SV600. The wrinkle and roughness parameters, R1, R2, R3, R4 and R5 were calculated and statistically analyzed. In addition, a subjective evaluation of product efficacy was conducted by patient's assessment. Results : The mean values of all the skin roughness parameters were decreased at 4-week, and decreased significantly at 8 and 12-week except R4 at 12-week after test product use. The subjective evaluation of wrinkle by patient's assessment was also improved. However, one patient noted stiffness of face after use of test product. Conclusions : These study suggested that the application of ampule containing herbal extract twice daily for 12 weeks may effectively improve the facial wrinkles without severe side effect.

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Reliability Growth Management for Armed Vehicle : Launcher System Case Study (기동장비 신뢰도 성장 관리 연구 : 발사대 체계 사례)

  • Lee, YJ;Bae, GB;Heo, YM;Seo, JH;Kim, SB;Choi, JK;Park, WJ
    • Journal of Korean Society for Quality Management
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    • v.45 no.4
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    • pp.981-994
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    • 2017
  • Purpose: In this study, the reliability growth management procedures for armed vehicle is suggested and an illustrative case study of launcher system is given. Methods: Crow-AMSAA model is adopted to manage reliability growth of armed vehicle using failure data acquired from development test phase to field operation phase. Between the development test phase and the production phase, the suggested reliability growth procedures for armed vehicle entails accelerated life test of the selected module whose design is changed to improve its reliability for assuring the target system reliability. And it can be verified through estimating the system reliability based on the failure data of field operation phase. Results: It is shown that the proposed reliability growth management procedures are effective for armed vehicle based on the case study of launcher system. After estimating the reliability of launcher system at every development test, some items are selected to change their designs for improving reliability. Accelerated life test is performed to prove the reliability improvement and finally it is verified through the field operation. Conclusion: The reliability growth management procedures for armed vehicle is suggested and the case study of launcher system shows it can be effective for managing the reliability growth of the armed vehicle.

A Hybrid Shadow Testing Scheme During Ray Tracing (광선추적 수행중 혼합 음영검사에 관한 연구)

  • Eo, Kil-Su;Kyung, Chong-Min
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.3
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    • pp.95-104
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    • 1989
  • This paper presents a new shadow testing acceleration scheme for ray tracing called Hybrid Shadow Testing (HST) based on a conditional switching between the conventinal shadow testing method and Crow's shadow volume method, where the shadow polygons as well as the object polygons are registered onto the corresponding cells under the 3-D space subdivision environment. Despite the preprocessing time for the generation and registration of the shadow polygons, the total shadow testing time of the proposed algorithm, HST was approximately 50% of that of the conventional shadow testing method for several examples while the total ray tracing time was typically reduced by 30% from the conventional approach. This due to the selective use of the shadow volume method with a compromise between the maximal utilisation of shadow's spatial coherency and minimising the computational overhead for checking ray intersections with the shadow polygons. A parameter, $N_{th}$ denoting the critical number of shadow polygons between successive reflection points was used as a guideline for switching the shadow testing scheme between the conventional method and shadow volume method. A method for calculating $N_{th}$ from such statistical data as the number of object polygons, average polygon size average peripheral length of the polygons was proposed, resulting in good agreement with the experimental results.

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Postmodern Animality and Spectrality: Ted Hughes's Wodwo and Crow

  • Park, Jung Pil
    • Journal of English Language & Literature
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    • v.58 no.6
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    • pp.1143-1165
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    • 2012
  • Tinted with ontological concern, Ted Hughes passes through an existential climate, eventually confirms death( or nothingness) as the new foundation of his poetry, and explores the various paradoxical effects of nothingness. Nihilism, fraught with rather negative and traumatic themes such as death, melancholy, and despair can, however, generate being (even in multiple modes), animalistic vitality, and insubstantial specters. Among these new functions of nothingness animality and spectrality are the most notable in Hughes's poetry. A considerable number of animals and bioorganisms that Hughes introduces exhibit the enormous energy derived from the dignity of death, from subversive challenges against the established hierarchy, and from new and dynamic multifaceted sources of nothingness. In other words, Hughes's animals, yield surplus power beyond themselves, as if they are demi-gods; in short, they feature the sublime as unidentified terrifying effects of nothingness. In a sense, animality means allowing some level of violence without legal sanction. Hughes inaugurates this kind of all bigotry-eradicating violence and attempts to subvert higher beings such as humans and gods, and existing doctrines: thrushes rise up against the animal and human worlds; a rush of ghostly crabs at night press through the human world. Hughes also resists the highest being, God, employing the technique of rewriting God's theology. Dirty, anomalous crows attack, subvert, and dismember the delicate, indurate, and thorough system of logos. Hughes, of course, does not place the animals merely in lofty regard, aware of the ulterior deprivation of the sublime animality, the trace of existential negativity. Thus, a seemingly omnipotent crow can become a mere beggar guzzling ice cream from the garbage bin on the beach. In addition, the violent and dignified aspects of nothingness can be transformed to reveal the thin and trivial traits as unreliable specters. Dark, heavy, and terrible nullity lessens its own volume and mass, and exposes the airy waves of shadows or specters. However, owing to nullity's untraceable track, the scarcity and unfamiliarity of the phantoms inversely display their foreign gigantic effects such as fantasy and violence.

Characteristics of High Energy Inductor to Generate Current Waveform of 10/350 ${\mu}s$ (10/350 ${\mu}s$ 전류파형을 형성하기 위한 대용량 인덕터 특성)

  • Lee, Tae-Hyung;Cho, Sung-Chul;Eom, Ju-Hong;Kim, Ki-Bok
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.331-334
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    • 2009
  • This paper presents the characteristics of external inductor for impulse current waveform with 10/350 ${\mu}s$ time parameters. Impulse generator was composed with capacitor having large capacitance and low working voltage for the safe of operator and small discharging sound. Parallel R-L-C circuits with crow-bar gaps and superposition method were proposed to make a high current lightning impulse according to IEC 62305-1. The high energy inductor with several taps for fitting half decay time T2 within the tolerance range and experimental data of inductance according to charging voltages were suggested.

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An improved Fault Ride Through control scheme for Doubly fed induction generator (이중여자 유도형 풍력발전기의 Fault Ride Through 향상 제어기법에 관한 연구)

  • Lee, Sung-Eun;Kim, Yun-Seong;Won, Dong-Jun
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1116_1117
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    • 2009
  • 전력계통에서의 풍력 발전의 설치가 증가하면서 사고 발생시 전체 계통에 대한 신뢰도 및 안정도에 영향을 미친다. 이를 고려한 Fault Ride Through 제어 기법은 보다 안정적인 계통운영을 위한 방안이다. 최근 대부분의 풍력발전시스템은 이중여자 유도형 발전시스템(DFIG)이 설치되는데, 이는 전력변환장치를 이용한 유효 및 무효 전력 제어가 가능한 가변속 풍력발전시스템이다. 본 논문은 PSCAD/EMTDC를 통해 DFIG를 모델링하고 Crow Bar와 Rotor Side Converter의 연계 제어를 이용한 Fault Ride Through 제어 기법을 시뮬레이션 결과를 통해 확인 하였다.

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