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The Workload Distribution Problems in a Class of Flexible Manufacturing Systems

  • Kim, Sung-Chul
    • Journal of Korean Institute of Industrial Engineers
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    • v.15 no.1
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    • pp.65-75
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    • 1989
  • This study complements the previous studies on workload distribution problems in Flexible Manufacturing Systems. Specifically, we consider the problem in two perspectives, the long-range policy and the short and medium-term planning and control. The long-term loading policy focusses on identifying the optimal loading of the system characterized by either balanced loading or unique unbalanced loading for which a steepest ascent method is developed. These results are then applied to study the optimal medium and short-term planning and control problems, for which a truncated dynamic programming method is developed in order to obtain the optimal allocation of the given operation mix of part types to work stations.

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Variations in the Na-O anticorrelation in globular clusters

  • Lee, Jae-Woo
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.27.1-27.1
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    • 2010
  • The Na-O anticorrelation seen in almost all globular clusters ever studied using high-resolution spectroscopy is now generally explained by the primordial pollution from the first generation of the intermediate-mass AGB stars to the proto-stellar clouds of the second generation of stars. Using the recent data by Carretta and his collaborators, the different shapes of the Na-O anticorrelations for RGB stars brighter than and fainter than the red giant branch bump can be clearly seen. If the elemental abundance measurements by Carretta and his collaborators are not greatly in error, this variation in the Na-O anticorrelation against luminosity indicates an internal deep mixing episode during the ascent of the low-mass RGB in globular clusters. Our result implies that the multiple stellar population division scheme solely based on [O/Fe] and [Na/Fe] ratios of a globular cluster, which is becoming popular, is not reliable for stars brighter than the RGB bump.

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A Study on the Fundamental Performance of Electric-driven Bollard (전동식 볼라드의 기본 성능에 관한 연구)

  • Park, Tae-Joon;Jung, Byeong-Gyu;Lee, Kee-Man
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.4
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    • pp.169-173
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    • 2011
  • This study is about the development of remote controlled bollard using the BLDC motor and ball screw with mechatronics theory. A bollard is composed of the sensor part and the control part. The sensor part is consisted of sensors that detect the locations of a bollard. The role of the control part is adjusting motor speed and power through variable resistance. In order to confirm required performance, the speed of decent and ascent of the bollard, the time and the RPM of BLDC motor were tested according to the variable resistance and the applied load with 10 to $72kg_f$.

Transnational Allegories of Image and Likeness in Louisa May Alcott's "Behind a Mask, or A Woman's Power"

  • Jin, Seongeun
    • American Studies
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    • v.43 no.1
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    • pp.83-97
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    • 2020
  • "Behind a Mask" (1866) marks the new direction of Louisa May Alcott's artistic and personal life. Her European trip solidified her identity as a mature woman, most importantly as a mature American woman, one whose independence from Victorian stereotypes would, from now on, make her fortune and fame. Her sensational stories, especially "Behind a Mask," would tell truths that readers recognized but had rarely seen written. These truths would free them, and the author herself, to explore their talents as individuals. Henceforth, Alcott would embody the successful American artistic entrepreneur as one who shed the European domination of false titles and inherited wealth. These motifs of the transnational connection pervade the story, in the form of images and likenesses. Just as Alcott would soon, in two years, reach astonishing financial success with the publication of Little Women, her meteoric ascent parallels America's rise to power in the world's economy, which came about with almost alarming speed after the conclusion of the American Civil War.

Calibration of flush air data sensing systems for a satellite launch vehicle

  • Mehta, R.C.
    • Advances in aircraft and spacecraft science
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    • v.9 no.1
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    • pp.1-15
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    • 2022
  • This paper presents calibration of flush air data sensing systems during ascent period of a satellite launch vehicle. Aerodynamic results are numerically computed by solving three-dimensional time dependent compressible Euler equations over a payload shroud of a satellite launch vehicle. The flush air data system consists of four pressure ports flushed on a blunt-cone section of the payload shroud and connected to on board differential pressure transducers. The inverse algorithm uses calibration charts which are based on computed and measured data. A controlled random search method coupled with neural network technique is employed to estimate pitch and yaw angles from measured transient differential pressure history. The algorithm predicts the flow direction stepwise with the function of flight Mach numbers and can be termed as an online method. Flow direction of the launch vehicle is compared with the reconstructed trajectory data. The estimated values of the flow direction are in good agreement with them.

GAN-based camouflage pattern generation parameter optimization system for improving assimilation rate with environment (야생 환경과의 동화율 개선을 위한 GAN 알고리즘 기반 위장 패턴 생성 파라미터 최적화 시스템)

  • Park, JunHyeok;Park, Seungmin;Cho, Dae-Soo
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.07a
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    • pp.511-512
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    • 2022
  • 동물무늬는 서식지에 따라 야생에서 천적으로부터 살아남을 수 있는 중요한 역할을 한다. 동물무늬의 역할 중 하나인 자연과 야생 환경에서 천적의 눈을 피해 위장하는 기능이 있기 때문인데 본 논문에서는 기존 위장무늬의 개선을 위한 GAN 알고리즘 기반 위장 패턴 생성모델을 제안한다. 이 모델은 단순히 색상만을 사용하여 위장무늬의 윤곽선을 Blur 처리를 해서 사람의 관측을 흐리게 만드는 기존의 모델의 단순함을 보완하여 GAN 알고리즘의 활용기술인 Deep Dream을 활용하여 경사 상승법을 통해 특정 층의 필터 값을 조절하여 원하는 부분에 대한 구분되는 패턴을 생성할 수 있어 색뿐만 아니라 위장의 기능이 있는 동물무늬와 섞어 자연과 야생 환경에서 더욱 동화율이 높아진 위장 패턴을 생성하고자 한다.

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Writing Miracles and Denominational Establishment: On the Belief Narratives of Quanzhen Daoism

  • ZHANG Shuqing
    • Journal of Daesoon Thought and the Religions of East Asia
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    • v.3 no.2
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    • pp.35-54
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    • 2024
  • This article focuses on the image of the ancestor of Quanzhen Daoism from a narrative perspective and also evaluates the influence of this image on the development of Quanzhen Daoism in terms of belief, genealogy, and the compilation of sacred history. Quanzhen Daoism has a rich tradition of narrating andwriting its history. In fact, narrating history is actually a form of constructing history. From the recounting of events such as the birth of the founder of the religion, Wang Chongyang (王重陽, 1112-1170), his conversion to Daoism, his practice and preaching, and his 'ascent to immortality' in Quanzhen historical hagiographies, readers can observe the recording of miracles as a narrative feature. The narratives of religious texts differ from ordinary historical narratives in that the former maintain the core concern of simultaneously promoting belief in miracles and strengthening the religious lineage of the respective tradition. Therefore, exploring the relationship between the narrative of the image of the ancestor and the development of the Quanzhen Sect, along with the establishment of beliefs, is the starting point of this article.

Statistical Optimization of Production Medium for Enhanced Production of Itaconic Acid Biosynthesized by Fungal Cells of Aspergillus terreus (Aspergillus terreus에 의해 생합성되는 이타콘산의 생산성 증가를 위한 통계적 생산배지 최적화)

  • Jang, Yong-Man;Shin, Woo-Shik;Lee, Do-Hoon;Kim, Sang-Yong;Park, Chul-Hwan;Jeong, Yong-Seob;Chun, Gie-Taek
    • KSBB Journal
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    • v.24 no.1
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    • pp.30-40
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    • 2009
  • Statistical optimization of the production medium was carried out in order to find an optimal medium composition in itaconic acid fermentation process. Itaconic acid utilized in the manufacture of various synthetic resins is a dicarboxylic acid biosynthesized by fungal cells of Aspergillus terreus in a branch of the TCA cycle via decarboxylation of cis-aconitate. Through OFAT (one factor at a time) experiments, six components (glucose, fructose, sucrose, soluble starch, soybean meal and cottonseed flour) were found to have significant effects on itaconic production among various carbon- and nitrogen-sources. Hence, using these six factors, interactive effects were investigated via fractional factorial design, showing that the initial concentrations of sucrose and cottonseed flour should be high for enhanced production of itaconic acid. Furthermore, through full factorial design (FFD) experiments, negative effects of $KH_2PO_4$ and $MgSO_4$ on itaconic acid biosynthesis were demonstrated, when excess amounts of the each component were initially added. Based on the FFD analysis, further statistical experiments were conducted along the steepest ascent path, followed by response surface method (RSM) in order to obtain optimal concentrations of the constituent nutrients. As a result, optimized concentrations of sucrose and cottonseed flour were found to be 90.4g/L and 53.8g/L respectively, with the corresponding production level of itaconic acid to be 4.36 g/L (about 7 fold higher productivity as compared to the previous production medium). From these experimental results, it was assumed that optimum ratio of the constituent carbon (sucrose) and nitrogen (cottonseed flour) sources was one of the most important factors for the enhanced production of itaconic acid.

Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology (반응표면분석법을 이용한 전도성물질의 절연코팅 프로세스의 최적화)

  • Sim, Chol-Ho
    • Korean Chemical Engineering Research
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    • v.54 no.1
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    • pp.44-51
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    • 2016
  • The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data ($Adj-R^2=0.944$). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was $530k{\Omega}{\cdot}cm$.

Interpretion of Transition between Explosive and Effusive Eruptions from Microlite Textural Analyses in the Albong Lava Dome, Ulleung Island, Korea (울릉도 알봉 용암돔의 미정 조직분석으로부터 폭발성 및 분류성 분출 간의 전환 해석)

  • Hwang, Sang Koo;Kim, Ki Beom;Son, Young Woo;Hyeon, Hye Weon
    • Economic and Environmental Geology
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    • v.53 no.5
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    • pp.553-564
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    • 2020
  • Transition between explosive and effusive eruption in Ulleung Island is observed in the Nari Scoria Deposits and Albong Trachyandesite (lava dome) origined by dome-building eruption and may be related to factors such as magma influx, ascent rate and degassing. However, the interpretation of them has not been resolved yet because the interaction between these factors is not complex but also the resulting behaviour during eruption is unpredictable. This paper focuses on the explosive and effusive activity perceived during building the Albong lava dome in Nari caldera. Samples were collected along with time from the scoria deposits and lava dome, linked to eruption stage and style of activity. Textures of groundmass feldspar microlites from these samples are quantitatively analyzed, including measurements of areal number density, mean microlite size, crystal aspect ratio, groundmass crystallinity and crystal size. The microlite textures show that shallow pre- and syn-eruptive magmatic processes acted to govern the changing behaviour during the eruption. Transition between explosive and effusive eruption was driven by the dynamics of magma ascent in the conduit, with degassing and crystallisation acting via feedback mechanisms, resulting in a cycle of effusive and explosive eruption.