• 제목/요약/키워드: continuum

검색결과 1,382건 처리시간 0.023초

무거운 별 탄생 지역인 DR21(OH) 천체에 대한 중수소화된 메탄올(CH3OD) 관측연구 (DEUTERATED METHANOL (CH3OD) IN THE HOT CORE OF THE MASSIVE STAR-FORMING REGION DR21 (OH))

  • 민영철
    • 천문학논총
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    • 제29권2호
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    • pp.29-34
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    • 2014
  • We have observed the deuterated methanol, $CH_3OD$, toward the hot core MM1 in the massive star-forming region DR21 (OH) using the Submillimeter Array with a high angular resolution of about 1 arcsecond. The position of the hot core associated with the sub-core MM1a was confirmed to coincide with the continuum peak where an embedded young stellar object is located. The column density of $CH_3OD$ was found to be about $(2{\pm}1){\times}10^{16}cm^{-2}$ toward the MM1a center. The abundance ratio $CH_3OD/CH_3OH$ was measured to be ~ 0.45, which is about the median value for low mass star-forming cores but much larger than those of the massive star-forming cores. The ratio is believed to change depending on, for example, the chemical condition, the temperature and the density of the source. This ratio may further depend on the evolutionary phase especially in the massive-star-forming cores. The sub-core MM1a is thought to be in the very early phase of star formation. This large abundance ratio found in this source indicates that even the massive star-forming cores, during a relatively short period in the very early stage of star formation, may also show a chemical state resulted from the cold and dense pre-collapsing phase, the enhanced deuteration as found in low mass star-forming cores.

Core formation in different environments: Planck Galactic Cold Clumps (PGCCs) in the λ Orionis cloud, Orion A and Orion B clouds

  • Yi, HeeWeon;Lee, Jeong-Eun;Liu, Tie;Kim, Kee-Tae;Wu, Yuefang
    • 천문학회보
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    • 제41권2호
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    • pp.37.4-38
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    • 2016
  • Based on the $850{\mu}m$ dust continuum data from James Clerk Maxwell Telescope (JCMT)/SCUBA-2, we compare overall properties of Planck Galactic Cold Clumps (PGCCs) in the ${\lambda}$ Orionis cloud with PGCCs in other molecular clouds, Orion A and Orion B. The Orion A and Orion B clouds are well known active star-forming region, while, ${\lambda}$ Orionis cloud has a different environment associating with prominent OB associations and a giant H II region. PGCCs in the ${\lambda}$ Orionis cloud have higher dust temperatures (Td~16.08 K) and lower values of dust emissivity (${\beta}{\sim}1.65$) than Orion A and Orion B clouds. In addition, we found the lowest detection rate (16 %, 8 out of 50) of PGCCs at $850{\mu}m$ in the ${\lambda}$ Orionis cloud while among three regions; Orion A and Orion B clouds show much higher detection rates of ~ 76 % (23 out of 30) and 56 % (9 out of 16), respectively. The detected 8 PGCCs in the ${\lambda}$ Orionis cloud have substructures and we identified 15 cores. The cores also show much lower median values of size (~0.08 pc), column density (~ ), number density (~ ), and mass (~ ) compared with other cores in the Orion A and Orion B clouds. These core properties in the ${\lambda}$ Orionis cloud can be attributed to the compression and external heating by the nearby H II region, which may prevent the PGCCs from forming gravitationally bound structures and eventually disperse them. These results well present the negative stellar feedback to core formation.

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A Search for Very Low-luminosity Objects in Gould Belt Clouds

  • Kim, Mi-Ryang;Lee, Chang Won;Dunham, Michael M.;Evans, Neal J II;Kim, Gwanjeong;Allen, Lori E
    • 천문학회보
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    • 제41권2호
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    • pp.38.3-39
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    • 2016
  • We present the results of a search for Very Low-Luminosity Objects (VeLLOs) in the Gould Belt (GB) clouds using infrared and sub-millimeter (sub-mm) data from 1.25 to $850{\mu}m$ and our N2H+ (J = 1-0) observations. We modified the criteria by Dunham et al. to select the VeLLOs in the GB clouds, finding 95 VeLLO candidates, 79 of which are newly identified in this study. Out of 95 sources, 44 were detected in both sub-mm continuum and N2H+ emission and were classified as Group A (the VeLLOs), and 51 sources detected in either sub-mm emission or N2H+ emission were classified with Group B as candidate VeLLOs. We find that these VeLLOs and the candidates are forming in environments different from those of the likely VeLLOs. Seventy-eight sources are embedded within their molecular clouds, and thus are likely VeLLOs forming in a dense environment. The remaining 17 sources are located in low-level extinction regions (Av < 1) connected to the clouds, and can be either background sources or candidate substellar objects forming in an isolated mode. The VeLLOs and the candidates are likely more luminous and their envelopes tend to be more massive in denser environments. The VeLLOs and the candidates are more populous in the clouds where more YSOs form, indicating that they form in a manner similar to that of normal YSOs. The bolometric luminosities and temperatures of the VeLLOs are compared to predictions of episodic accretion models, showing that the low luminosities for most VeLLOs can be well explained by their status in the quiescent phases of a cycle of episodic mass accretion.

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간호과장의 지도성 유형과 병원 조직풍토와의 관계 (A Study on the Relationships Between the chief Nurse′s Leadership style and the organizational climate of Hospitals)

  • 김영매;한상임
    • 대한간호학회지
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    • 제5권1호
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    • pp.79-86
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    • 1975
  • It had been thought the role of Nursing administrator was still not started along the right line in Korea because of the Lacking of full understanding and recognition of the real meaning of administrator's role, and because there are several Rinds of problems and difficulties in actual role. The present study is an attempt to clarify some existing relationships between the chief Nurse's Leadership style and the organizational climate of Hospitals. The problems of the study are specifically started as follows ; 1) What influence does the individual behavior have on the formation of the organizational climate of Hospital? 2) From what do the difference of climate arise? 3) How are the individual be heavier and organizational climate of Hospital measured ? In order to see the relationships or the interactions between the two factors, the chief nurse's Leadership style and organizational climate of hospital , the researcher has classified. He former into; 1) effective Leadership style. 2) initiating structure leader ship style. 3) Consideration structure Leadership style, and 4) ineffective Leadership style, and the latter in to. 1) open climate and 2) closed climate The Chief Nurses Leadership style has been. Classified into consideration-human relations approaches and initiating structure approaches according to L. B. D. Q by Hapin. Organizational climate of hospital has been classified into open-closed continuum according to O. C. H Q. by Hairpin and Croft. The results obtained are as follows : 1) The chief nurse's Leadership style is closer to Initiating structure Leadership style than Consideration structure lure Leadership style. 2) The organizational climate of hospital is closer to open climate than closed climate. 3) The chief nurse's Leadership sty]e and the organizational climate of hospital to not show any significant relations.

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지반조건이 Piled Raft 기초의 거동에 미치는 영향 평가를 위한 매개변수 연구 (A Parametric Study to Estimate the Behavior of a Piled Raft Foundation Influenced by Ground Conditions)

  • 유광호;정연학
    • 한국지반공학회논문집
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    • 제32권8호
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    • pp.35-46
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    • 2016
  • 본 연구에서는 지반조건에 따른 실제 piled raft 기초의 거동을 실규모 시험을 통해 분석하기가 어려운 점을 감안하여 수치해석을 이용한 민감도분석을 수행하고자 하였다. 수치해석에 사용한 프로그램은 유한차분법 기반의 FLAC 3D이다. 말뚝의 수치해석 모델링은 FLAC의 구조요소 중 하나인 말뚝요소를 사용하여 모델링하였고, 지반과 래프트는 연속체 요소를 이용하여 모사하였다. 말뚝의 배열은 $3{\times}3$으로 고정하고 말뚝직경, 말뚝길이, 말뚝간격 그리고 지반조건을 민감도 매개변수로 선정하고 상관관계를 규명하였다. 그 결과, 말뚝직경이 크고 말뚝의 길이가 길수록, 그리고 말뚝의 간격이 넓을수록 piled raft 기초의 전체 지지력은 증가하는 것으로 나타났다. 그러나 지반조건에 따라 말뚝간격이 일정 간격 이상이 될 경우, piled raft 기초의 거동이 래프트만으로 지지되는 얕은기초와 유사한 거동을 보였다. 또한 지반조건이 좋아질수록, piled raft 기초의 전체 지지력은 증가함을 확인할 수 있었다.

충주시 가로변 토양과 가로수 식생에 미치는 계절별 제설제의 영향 (The Seasonal Impacts of De-icing Salts on Soil and Vegetation in Chung-ju City)

  • 김재영;박주영;윤용한;주진희
    • 한국환경과학회지
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    • 제26권8호
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    • pp.993-998
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    • 2017
  • De-icing salts applied to roads during winter enable safe driving conditions. However, these salts are eventually displaced to roadside areas at which they can negatively impact soil, vegetation, and water resources. This purpose of this study is to determine the relationship between foliar damage ratio (NY = 0-25%, SY = 26-50%, CY = 51-75%) on roadside trees (Ginko biloba) and seasonal impact of de-icing salts on soil and vegetation. Thirty roadside trees were selected at 8 m intervals between the Konkuk and Judeok intersections in Chung-ju city. The results reveal that seasonal soil acidity is relatively alkaline for foliar damage ratio of Ginko biloba was CY compared to NY. Also, electronic conductivity of each seasonal sampling was recorded as high in winter and spring, whereas the opposite trend is observed in summer. Various plants species were identified in abundance under roadside trees within NY roadside sections. These same species were observed in reduced numbers within CY sections. Strong negative correlations were identified between foliar damage ratio on roadside trees and vegetation. This relationship may be a method to use in predicting the accumulation of de-icing salt and visible injuries on roadside trees.

Korean /l/-flapping in an /i/-/i/ context

  • Son, Minjung
    • 말소리와 음성과학
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    • 제7권1호
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    • pp.151-163
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    • 2015
  • In this study, we aim to describe kinematic characteristics of Korean /l/-flapping in two speech rates (fast vs. comfortable). Production data was collected from seven native speakers of Seoul Korean (four females and three males) using electromagnetic midsagittal articulometry (EMMA), which provided two dimensional data on the x-y plane. We examined kinematic properties of the vertical/horizontal tongue tip gesture, the vertical/horizontal (rear) tongue body gesture, and the jaw gesture in an /i/-/i/ context. Gestural landmarks of the vertical tongue tip gesture are directly measured. This serves as the actual anchoring time points to which relevant measures of other trajectories referred. The study focuses on velocity profiles, closing/opening spatiotemporal properties, constriction duration, and constriction minima were analyzed. The results are summarized as follows. First, gradiently distributed spatiotemporal values of the vertical tongue tip gesture were on a continuum. This shows more of a reduction in fast speech rate, but no single instance of categorical reduction (deletion). Second, Korean /l/-flapping predominantly exhibited a backward sliding tongue tip movement, in 83% of production, which is apparently distinguished from forward sliding movement in English. Lastly, there was an indication of vocalic reduction in fast rate, truncating spatial displacement of the jaw and the tongue body, although we did not observe positional variations with speech rate. The present study shows that Korean /l/-flapping is characterized by mixed articulatory properties with respect to flapping sounds of other languages such as English and Xiangxiang Chinese. Korean /l/ flapping demonstrates a language-universal property, such as the gradient nature of its flapping sounds that is compatible with other languages. On the other hand, Korean /l/-flapping also shows a language-particular property, particularly distinguished from English, in that a backward gliding movement occurs during the tongue tip closing movement. Although, there was no vocalic reduction in V2 observed in terms of jaw and tongue body height, spatial displacement of these articulators still suggests truncation in fast speech rate.

암을 처음 진단받은 환자를 위한 신환 네비게이션 프로그램 개발 및 효과 평가 (Development and Evaluation of a Navigation Program for Newly Diagnosed Cancer Patients)

  • 권인각;홍진영;백혜진;김성;남석진;김임령;김혜정;김애란
    • 임상간호연구
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    • 제18권1호
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    • pp.111-125
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    • 2012
  • Purpose: The purposes of this study were to develop a navigation program for newly diagnosed cancer patients and to evaluate its effects. Methods: The navigation program was based upon Professional Navigation Framework. Patients were asked to complete self-administered questionnaires on satisfaction, distress, anxiety and depression for evaluating the program. Results: The navigation program consisted of facilitating two concepts: continuity of care and empowerment of patients. Information-education package, telephone counseling and navigator's phone number were provided to the newly diagnosed cancer patients for care continuity. Self-care diary and emotional support by telephone counseling were provided to the patients for empowerment of patients. A total of 163 patients - 78 control and 85 experimental participants - were included in the study. The mean scores of satisfaction, distress, anxiety and depression had no statistical differences between the two groups after program implementation. In patients with longer waiting days, the experimental group with the navigation program showed higher relational continuity than the control group after program implementation(p=.023). In patients with longer waiting days or with higher distress, satisfaction of relational continuity was improved after program implementation in the experimental group. Conclusion: The navigation program in this study has applied the concept of patient navigation into oncology clinical setting in Korea. Navigation program can play a significant role in assisting patients navigating across the care continuum.

대학생 자원봉사자가 지각한 슈퍼바이저의 자율성지지, 자원봉사동기 및 지속의도 간의 관계 분석 (The Relationships Between Perception of Supervisors' Autonomy Support, Volunteer Motivation and Persistence Intentions Among Collegiate Volunteers)

  • 홍연숙
    • 한국사회복지학
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    • 제62권4호
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    • pp.103-128
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    • 2010
  • 본 연구의 목적은 제주지역사회에서 자원봉사활동에 참여하는 515명의 대학생을 대상으로 슈퍼바이저의 자율성지지, 자원봉사동기 및 지속의도간의 인과관계를 분석하는 것이었다. 상관관계분석, 공변 량구조분석을 통하여 다음과 같은 결과를 얻었다. 첫째, 자원봉사동기들은 서열화 된 상관패턴을 보여 주었다. 둘째, 자원봉사자가 지각하는 슈퍼바이저의 자율성 지지는 자율적 동기인 내재적 동기와 확인적 조절동기에 유의한 정(+)의 영향을 미쳤고, 통제적 동기(내사적, 외적 조절동기)에는 유의한 영향을 미치지 못하였으며, 무동기에는 부(-)의 영향을 미쳤다. 셋째, 자율적 동기인 내재적 동기, 확인적 조절동기들은 향후 자원봉사활동 지속의도에도 유의한 정(+)의 영향을 미쳤으며, 확인적 조절의 외재적 동기가 지속의도의 최적 예측변인으로 나타났다. 자원봉사영역에서 자기결정이론의 응용가능성과 유망성에 대하여 논의하였다.

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FIR Observations and Simple LVG Modeling Results of L1448-MM

  • 이진희;이정은;이석호
    • 천문학회보
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    • 제37권1호
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    • pp.82.2-82.2
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    • 2012
  • We present Herschel-PACS observations of L1448-MM, a Class 0 protostar with a prominent outflow, part of the DIGIT Key Program (PI: N. Evans). We detect numerous emission lines including CO and $H_2O$ rotational transitions, OH transitions, and [OI] forbidden transitions at wavelengths from 55 to 210 ${\mu}m$. The $H_2O$, [OI], mid-J CO (J < 23), and OH emission distributes along the outflow direction although high-J CO and other OH emission peaks at the central spatial pixel. According to our simple excitation analysis, CO seems to have two temperature components of warm and hot, which might be attributed to the PDR and shock, respectively. After exploring a wide range of physical conditions with a non-LTE LVG code, RADEX, we found that either shock alone or the combination of PDR and shock can explain the observations. The relative fraction of observed line luminosities suggest that L1448-MM is shielded from the UV radiation because $H_2O$ and CO are the dominant coolants rather than OH and [OI]. In addition, our observed fluxes match better with C-shock models rather than J-shocks. The non-LTE LVG model supports that the IR pumping process is important for OH transitions because the OH line ratios are fitted much better when the dust thermal continuum is included.

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