• Title/Summary/Keyword: STELLA

Search Result 93, Processing Time 0.03 seconds

Turbulent Properties in Two Molecular Clouds: Orion A and ρ Ophiuchus

  • Yun, Hyeong-Sik;Lee, Jeong-Eun;Choi, Yunhee;Lee, Seokho;Choi, Minho;Kang, Hyunwoo;Tatematsu, Ken'ichi;Offner, Stella S.R.;Gaches, Brandt A.L.;Heyer, Mark H.;Evans, Neal J. II;Yang, Yao-Lun
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.42 no.1
    • /
    • pp.33.1-33.1
    • /
    • 2017
  • Molecular clouds are the sites of stellar birth, and conditions within the clouds control the mode and tempo of star formation. In particular, turbulence largely determines the density and velocity fields, and can affect the gas kinetic temperature as it decays via shocks. However, despite its central role in star formation and many years of study, the properties of turbulence remain poorly understood. As a part of the TRAO key science program, "Mapping turbulent properties of star-forming molecular clouds down to the sonic scale (PI: Jeong-Eun Lee)", we mapped the northern region of the Orion A molecular cloud and the L1688 region of the ${\rho}$ Ophiuchus molecular cloud in 2 sets of lines (13CO 1-0/C18O 1-0 and HCN 1-0/and HCO+ 1-0) using the Taeduk Radio Astronomy Observatory (TRAO) 14-m telescope. We analyze these maps using a python package 'Turbustat', a toolkit which contains 16 different turbulent statistics. We will present the preliminary results of our TRAO observations and various turbulence statistical analyses.

  • PDF

A Study on the Influence of Self-driving Patents on the Firm Performance in the Automotive Parts Industry (자율주행 관련 특허의 자동차 부품 산업 내 기업 성과에 미치는 영향에 관한 분석)

  • Cho, Hyunseok;Kwak, Chanhee;Choi, HanByeol Stella;Lee, Minhyung;Lee, Heeseok
    • Knowledge Management Research
    • /
    • v.20 no.4
    • /
    • pp.57-74
    • /
    • 2019
  • Self-driving technology is changing the paradigm of automotive industry. Since it is imperative to converge this emerging technology with ICT and there is a time lag between securing this emerging technology and occurrence of firm performance, it is difficult to make decisions on technology development. This study investigates patent indicators to understand the impact of self-driving technology on performance of automotive parts companies. We analyze 611 of self-driving technology patents from 2000 to 2016 and the financial performance of 270 small and medium businesses that register the corresponding patents with consideration of up to four years of time lag. Our analysis results show that patents related to self-driving has a positive impact on asset growth of 2 years and sales growth of 3 years in terms of time lag. This study contributes to the literature by analyzing the impact of technology development on the firm performance in case of convergence of the automotive and ICT industries. Additionally, this study provides a role of patent in knowledge management planning through technology development as a practical implication.

Cardiocirculatory, biochemical and hemostatic evaluation of dogs with hyperadrenocorticism at diagnosis and after treatment

  • Soares, Frederico Aecio Carvalho;Matheus, Juliana Pereira;Carvalho, Guilherme Luiz;Neuwald, Elisa Barp;Poppl, Alan Gomes;Valle, Stella Faria;Gonzalez, Felix Hilario Diaz
    • Korean Journal of Veterinary Research
    • /
    • v.56 no.3
    • /
    • pp.161-166
    • /
    • 2016
  • Hyperadrenocorticism (HAC) is a common endocrinopathy among dogs that causes multisystemic signs. This study was conducted to evaluate cardiocirculatory, biochemical, and hemostatic parameters in dogs with HAC at diagnosis, in addition to verifying whether abnormal parameters could be controlled by initial treatment with trilostane. Fifteen dogs with HAC were assessed by systolic blood pressure measurement, electrocardiography, Doppler echocardiography, serum concentration of troponin I, and biochemical and hemostatic profile at diagnosis and after trilostane therapy. Unlike biochemical parameters, hemostatic and cardiocirculatory parameters were not significantly influenced by the onset of treatment. The authors believe that clinical treatment with trilostane for 3 to 4 months might not be sufficient for the stabilization of cardiocirculatory abnormalities such as hypertension. Therefore, dogs with HAC must receive cardiocirculatory monitoring at diagnosis and during drug treatment.

SENSITIVITY OF THE KEUM RIVER BASIN TO CLIMATE CHANGE

  • Kim, Young-Oh;Seo, Yong-Won;Lee, Seung-Hyun;Lee, Dong-Ryul
    • Water Engineering Research
    • /
    • v.1 no.4
    • /
    • pp.267-277
    • /
    • 2000
  • This study reports an examination of the sensitivity of water resources in the Keum River basin to climate change. Assuming a doubling in $CO_2$ concentrations, a cooperative study provided four climate change scenarios for this study, which have been translated into temperature and precipitation scenarios on a basin scale. The study utilized these temperature and precipitation data for each climate change scenario as inputs to the NWS-PC model to generate the corresponding streamflow scenario over the Keum River basin. A reservoir simulation model for the Dae-Chung Dam in the Keum River basin has been developed with an object-oriented simulation environment, STELLA. For each streamflow scenario, the performance of the reservoir was assessed in terms of reliability, resiliency, and vulnerability. Although the simulation results are heavily dependent on the choice of the climate change scenarios, the following conclusions can be clearly concluded: (1) the future streamflow over the Dae-Chung Dam tends to decease during the dry period, which seriously increases competitive water use issues and (2) flood control issues predominate under the $2CO_2$-High case.

  • PDF

Microstructure and Properties of Fully Aliphatic Polyimide/Mesoporous Silica Hybrid Composites

  • Mathewst, Anu Stella;Jung, Yu-In;Lee, Tae-Sung;Park, Sung-Soo;Kim, Il;Ha, Chang-Sik;Selvaraj, M.;Han, Mi-Jeong
    • Macromolecular Research
    • /
    • v.17 no.9
    • /
    • pp.638-645
    • /
    • 2009
  • We report the effect of the amount of the mesoporous material, SBA-15, on the basic traits of fully aliphatic polyimides (API). For this purpose, water soluble, fully aliphatic poly(amic acid) triethyl amine salts ($PAA_{(s)}$) were prepared and mixed with various amounts of SBA-15. Fully aliphatic polyimide hybrid composites containing the SBA 15-type mesoporous silica were synthesized successfully from bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and alicyclic diamine, 4,4'-methylene bis(2-methylcyclohexylamine). The structure of the hybrid composites was confirmed by IR spectroscopic analysis. Scanning electron microscopy revealed the morphology of the compounds. The hybrid composites exhibited good thermal stability, reasonable transparency, and a low dielectric constant.

Synthesis, Characterization, and Properties of Fully Aliphatic Polyimides and Their Derivatives for Microelectronics and Optoelectronics Applications

  • Mathews Anu Stella;Kim Il;Ha Chang-Sik
    • Macromolecular Research
    • /
    • v.15 no.2
    • /
    • pp.114-128
    • /
    • 2007
  • Polyimides are one of the most important classes of polymers used in the microelectronics and photoelectronics industries. Because of their high thermal stability, chemical resistance, and good mechanical and electric properties, polyimides are often applied in photoresists, passivation and dielectric films, soft print circuit boards, and alignment films within displays. Recently, fully aliphatic and alicyclic polyimides have found applications as optoelectronics and inter layer dielectric materials, due to their good transparencies and low dielectric constants $(\varepsilon)$. The low molecular density, polarity and rare probability of forming inter- or intra-molecular charge transfers, resulting in lowering of the dielectric constant and high transparency, are the most striking characteristics of aliphatic polyimide. However, the ultimate end use of polyimides derived from aliphatic monomers is in their targeted applications that need less stringent thermal requirements. Much research effort has been exerted in the development of aliphatic polyimide with increased thermal and mechanical stabilities, while maintaining their transparencies and low dielectric constants, by the incorporation of rigid moieties. In this article, the recent research process in synthesizing fully aliphatic polyimides, with improved dimensional stability, high transparency and low $\delta$values, as well as the characterizations and future scope for their application in micro electric and photo-electronic industries, is reviewed.

Phases of Alienation in Le Torrent by Anne Hébert (안느 에베르의 중·단편집 『격류』에 드러나는 소외의 시대상)

  • Kang, Choung-Kwon
    • Cross-Cultural Studies
    • /
    • v.39
    • /
    • pp.7-32
    • /
    • 2015
  • In 1950, Anne $H{\acute{e}}bert$ published Le Torrent, a collection of seven short stories. These stories containing many shocking themes and expressions have placed her one of the pioneers of modern novels in Quebec. This paper tries to analyze several phases of alienation described in the novels and the reactions of alienated caracters in their situation. Some examples of alienated and mentally or physically deformed characters in Le Torrent are Fran?ois, $St{\acute{e}}phanie$, Stella, etc. Although the author wanted readers to interpret these characters on ther individual level, this paper interprets them differently. The result of this study is as following. Alienation doesn't come from one's interior but his exterior. Society and history are major agents of alienation. The injustice of life imposed on the caracters results from political and religious underdevelopment, cultural lowness, absence of social security system and of universal education at that time. The conquest of Quebec by England left a deep and historical wound on the French Canadians. This fact is, in my opinion, one of the essential themes of Anne $H{\acute{e}}bert^{\prime}s$ novels. In spite of all these alienating situations, the reactions showed by the caracters of the novels are limited to escapist illusion, self-destruction, mistaken revenge, eternal submission, etc. In conclusion, Le Torrent by Anne $H{\acute{e}}bert$ which deeply approached themes of violence and alienation could be called authentic landscape of the inner world of Quebecois before 'la Revolution tranquille.'

Reliability and Validity of the Appropriateness Evaluation Protocol for Public Hospitals in Korea

  • Lee, Clara;Kim, Stella Jung-Hyun;Lee, Changwoo;Shin, Euichul
    • Journal of Preventive Medicine and Public Health
    • /
    • v.52 no.5
    • /
    • pp.316-322
    • /
    • 2019
  • Objectives: This study was conducted to assess the applicability of the Appropriateness Evaluation Protocol (AEP) for public hospitals in Korea. Methods: In May 2016, 1500 admission claims were collected from Korean public district hospitals using stratified random sampling. Of these claims, 560 admissions to 37 hospitals were retrieved for analysis. Medical records administrators determined the appropriateness of admission using the criteria detailed in the AEP, and a physician separately assessed the appropriateness of admission based on her clinical judgment. To examine the applicability of the AEP, the concordance of the decisions made between a pair of AEP reviewers and between an AEP reviewer and a physician reviewer was compared. Results: The results showed an almost perfect inter-rater agreement between the AEP reviewers and a moderate agreement between the AEP reviewers and the physician. The sensitivity and specificity of the AEP were calculated as 0.86 and 0.56, respectively. Conclusions: Our findings suggest that the AEP could potentially be applied to Korean public hospitals as a reliable and valid instrument for assessing the appropriateness of admissions.

Numerical analysis of the temperature distribution of the EM pump for the sodium thermo-hydraulic test loop of the GenIV PGSFR

  • Kwak, Jaesik;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
    • /
    • v.53 no.5
    • /
    • pp.1429-1435
    • /
    • 2021
  • The temperature distribution of an electromagnetic pump was analyzed with a flow rate of 1380 L/min and a pressure of 4 bar designed for the sodium thermo-hydraulic test in the Sodium Test Loop for Safety Simulation and Assessment-Phase 1 (STELLA-1). The electromagnetic pump was used for the circulation of the liquid sodium coolant in the Intermediate Heat Transport System (IHTS) of the Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR) with an electric power of 150 MWe. The temperature distribution of the components of the electromagnetic pump was numerically analyzed to prevent functional degradation in the high temperature environment during pump operation. The heat transfer was numerically calculated using ANSYS Fluent for prediction of the temperature distribution in the excited coils, the electromagnet core, and the liquid sodium flow channel of the electromagnetic pump. The temperature distribution of operating electromagnetic pump was compared with cooling of natural and forced air circulation. The temperature in the coil, the core and the flow gap in the two conditions, natural circulation and forced circulation, were compared. The electromagnetic pump with cooling of forced circulation had better efficiency than natural circulation even considering consumption of the input power for the air blower. Accordingly, this study judged that forced cooling is good for both maintenance and efficiency of the electromagnetic pump.

An Analysis of Sustainable Macro Trends of Luxury Fashion Brands (럭셔리 패션 브랜드의 지속가능 매크로 트렌드 분석)

  • Lee, Hojae;Ko, Eunju
    • Journal of Fashion Business
    • /
    • v.26 no.1
    • /
    • pp.16-29
    • /
    • 2022
  • Environmental problems increasingly serious, and sustainability in the fashion industry has become an essential factor. Nowadays, numerous brands are engaging in sustainable fashion activities, such as recycling, vegan, fair trade, etc., which have not been done before. However, there are limited studies about sustainable fashion activities focusing on luxury brands. The purpose of this study is to establish the current status of luxury brands' sustainable fashion activities based on the macro trend of Todeschini et al(2017)'s thesis. This study selected six global luxury fashion brands Louis Vuitton, Hermes, Gucci, Prada, Burberry, and Stella McCartney. Data were collected from the brand's websites and reports, fashion magazines, and Google. As a result of the study, the following adjustments are being implemented; first, efforts are being made to reduce the consumption of natural resources. Second, transparency on working conditions is provided in various ways. Third, luxury brands' awareness of the sharing economy was not opened. Fourth, efforts are being made to develop eco-friendly materials and technologies to minimize wastage. Based on these research results, if applied as basic data for the development of Korean fashion brands and start-up companies, it will help establish directions of sustainable fashion strategies.