• 제목/요약/키워드: pre-transition

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The Early Chemical Enrichment Histories of Two Sculptor Group Dwarf Galaxies as Revealed by RR Lyrae Variables

  • Yang, Soung-Chul;Wagner-Kaiser, Rachel;Sarajedini, Ata;Kim, Sang Chul;Kyeong, Jaemann
    • 천문학회보
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    • 제39권1호
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    • pp.39.1-39.1
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    • 2014
  • We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys (ACS) onboard the Hubble Space Telescope (HST), we have identified a sample of RR Lyrae candidates in both dTrans galaxies [219 RRab (RR0) and 13 RRc (RR1) variables in ESO294-G010; 225 RRab and 44 RRc stars in ESO410-G005]. The metallicities of the individual RRab stars are calculated via the period-amplitude-[Fe/H] relation derived by Alcock et al. This yields mean metallicities of <[Fe/H]>_{ESO294} = -1.77 +/- 0.03 and <[Fe/H]>_{ESO410} = -1.64+/- 0.03. The RRL metallicity distribution functions (MDFs) are investigated further via simple chemical evolution models; these reveal the relics of the early chemical enrichment processes for these two dTrans galaxies. In the case of both galaxies, the shapes of the RRL MDFs are well-described by pre-enrichment models. This suggests two possible channels for the early chemical evolution for these Sculptor group dTrans galaxies: 1) The ancient stellar populations of our target dwarf galaxies might have formed from the star forming gas which was already enriched through "prompt initial enrichment" or an "initial nucleosynthetic spike" from the very first massive stars, or 2) this pre-enrichment state might have been achieved by the end products from more evolved systems of their nearest neighbor, NGC 55.

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Effects of Caloric Restriction on Endocrine Functions and Body Fat Distribution in Overweight Premenopausal Women, Related to their UCP3 (Uncoupling Protein 3) Genotypes

  • Lee, Jong-Ho;Kim, Oh-Yoen;Kim, Ji-Young;Park, Kyoung;Yangsoo Jang
    • Nutritional Sciences
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    • 제5권1호
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    • pp.13-19
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    • 2002
  • A mutation in the promoter region of uncoupling protein 3 (UCF3), specifically the -55C longrightarrow T transition, may influence an individual's energy metabolism and body weight. The objective of this study was to investigate the effect of a weight reduction program on endocrine functions and body fat distribution, related to UCP3 promoter genotype. Ninety overweight pre-menopausal female subjects participated in the weight reduction program at Yonsei University Hospital, and were placed on a calorie-restricted diet (300 kcal less than their daily requirements) for 12 weeks. After 12 weeks, all subjects on the program lost approximately 5% of their initial body weights and had lower Body Mass Index (BMI) values. Among the 90 women, 56 had a normal (without mutation) UCP3 genotype, while 34 women had mutations in the promoter region of UCP3. Despite similar weight reductions in both groups, a significantly higher decrease in abdominal adipose tissue was observed in the normal UCP3 genotype group, compared to the group with mutations. In particular, there was a significant reduction of fat at the lumbar 1 (Ll) level in the without-mutation group. Serum levels of total cholesterol, apolipoprotein Al were significantly decreased in the without-mutation group, by 4.4% and 5.7% respectively. Serum levels of hormones were not significantly changed in both groups artier the intervention. However, in the group without the mutations, the leptin level significantly reduced by 23.4% (p<0.001). Serum free fatty acid (FFA) concentration was significantly increased in the group with mutation following the weight reduction program. On the other hand, FFA responses were shown similar increases in both groups. In conclusion, although no difference was found in the magnitude of weight reduction in both groups, there were significant differences in body fat distribution and in endocrine function between the groups.

융·복합 학문으로서 내러티브 과학의 시사점 및 방향 탐구 (In Search of Narrative Science as a Convergence Discipline and its Implication and Direction)

  • 강현석;이지은
    • 예술인문사회 융합 멀티미디어 논문지
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    • 제7권5호
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    • pp.45-53
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    • 2017
  • 그동안의 학문분야는 한국연구재단에 따라 그 영역이 세분화되어 있었으며, 단일 학문의 발전에 큰 기여를 한 바 있다. 그러나 새로운 트렌드에 따라 융·복합으로의 전환이 필요한 실정이다. 이에 본 연구에서는 그러한 해결책을 제시해줄 수 있는 융·복합 학문으로서 내러티브 과학의 정의와 그 특성을 탐구하였으며, 이에 따른 시사점과 앞으로의 과제를 도출하는 데 연구의 목적이 있었다. 내러티브 과학은 내러티브 인식론에 바탕을 둔 인간과학으로서, 인간의 해석능력과 소통능력 및 간주관성에 초점을 둔다. 이러한 내러티브 과학은 그 특성에 따라 여러 구조를 갖고 있으며, 기존의 학문체계에 있어 내러티브적 상호연관성을 제공하고 인간 내부의 영역에도 주목을 하는 시사점을 제공한다. 이러한 내러티브 과학이 앞으로 발전하기 위해서는 서사학이라는 오해와 질적 연구라는 단일한 연구방법론의 편견으로부터 벗어날 필요가 있다. 이러한 변화에 유의하면서 내러티브 과학 분야는 내러티브 철학과 심리학을 토대로 인간과학의 측면에서 융·복합적으로 탐구될 필요가 있다.

범이론적모형과 생활기술접근법을 통합적용한 군인.전의경 대상 금연클리닉프로그램의 효과 (The Effects of Smoking Cessation Clinics in the Korean Armed Forces: Application of the Transtheoretical Model and Life Skill Approaches)

  • 김혜경;권은주;임재호;정혜인;차재구;조선;김수영;엄수진;박지연;조한익
    • 보건교육건강증진학회지
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    • 제28권4호
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    • pp.79-94
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    • 2011
  • Objectives: The aim of this study was to evaluate the effectiveness of smoking cessation clinics for soldiers in the Korean armed forces. In so doing it attempted to identify the predictors of smoking cessation and positive transition of stages of change. Methods: In a single-group pre-post test study design, 5,362 smokers from Korean armed forces participated in the smoking cessation clinic programs based on both the Transtheoretical model and life skills approaches. Changes in stages of change and related variables were measured before the intervention and at 3-month follow-up after the intervention. Results: The cessation rates was 66.0% at 3-month follow-up. With the positive transition to action/maintain stage, proportion of participants in action/maintain stage increased more than 5 times after the intervention. Cons of smoking, self-efficacy, processes of change, and life skills increased, and pros of smoking decreased after the intervention. Predictors of smoking cessation included nicotine dependency, pros of smoking, high levels of self-efficacy, processes of change and life skills. Positive stage transition was predicted by pros of smoking and high self-efficacy. Conclusions: Application of the Transtheoretical model and life skills approaches provided useful strategies for a smoking cessation program in armed forces.

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

  • 황상구;김기범;손영우;현혜원
    • 자원환경지질
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    • 제53권5호
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    • pp.553-564
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    • 2020
  • 울릉도에서 폭발성 및 분류성 분출 간의 전환은 돔형성 분출을 나타내는 나리분석층과 알봉조면안산암(용암돔)에서 관찰되며, 유동성 마그마, 상승률 및 탈기작용과 같은 요인과 연관된다. 그러나 이들에 대한 해석은 요인들 간의 상호작용이 복잡할 뿐만 아니라 분출과정에서의 거동을 예측하기 어렵기 때문에 지금까지 해결되지 않았다. 이 논문은 나리 칼데라에서 알봉 용암돔 형성과정에서 인지되는 폭발성 및 분류성 분출에 초점을 두었다. 시료는 분석층과 용암돔에서 시간에 따라 채취하였으며, 분출 단계 및 활동 양식과 연계되어 있다. 이 시료들에서 석기 장석미정의 조직은 면적 개수밀도, 평균 미정크기, 결정 종횡비, 석기 결정률 등을 포함하며 정량적으로 분석되었다. 이러한 미정의 조직은 천부에서 분출전 및 분출동시 마그마 과정이 분출 동안 거동변화를 제어하면서 진행되었다는 것을 보여준다. 폭발성 및 분류성 분출 간의 전환은 주로 화도 내 마그마 상승의 역학관계에 의해 일어났으며, 탈기작용과 결정작용이 피드백 메카니즘을 통해 일어남으로서 분류성 및 폭발성 분출의 한 윤회를 초래했다.

청년층의 첫 일자리 진입 : 경제위기 전후의 비교 (Duration to First Job of Korean Young Graduates: Before and After the Economic Crisis)

  • 안주엽;홍서연
    • 노동경제논집
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    • 제25권1호
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    • pp.47-74
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    • 2002
  • 경제위기 직후 실업률의 급상승과 함께 경기변동에 민감한 청년층의 실업률은 15~20%까지 상승하였다. 경기회복에도 불구하고 신규학졸자의 첫 일자리 취업에는 상당한 애로가 존재하고 청년층의 유휴화율은 여전히 심각한 수준이다. 청년층 유휴화의 부정적 효과에도 불구하고 청년층의 학교교육-노동시장 이행과정에 관한 연구는 일천하다. 본 연구는 "한국노동패널" 3차년도(2000년)에 실시한 "청년층 부가조사" 자료를 이용하여 15~29세 청년층이 최종 학교를 마치고 첫 일자리를 취득하는 데 소요되는 미취업 경과기간을 분석한다. 미취업상태가 경과할수록 탈출확률이 낮아지는 부(-)의 경과 기간 의존성이 나타나며, 예상과는 달리, 여성의 탈출확률이 남성보다 높게 나타난다. 학력수준의 탈출확률에 대한 효과는 경제위기 이전에는 유의하지 않게 나타나나 경제위기 이후에는 뚜렷한 것으로 나타난다. 경제위기 이전 졸업자 표본은 높은 실업률이 탈출확률을 낮추는 반면 경제위기 이후 졸업자 표본은 정반대의 결과를 보여준다.

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분만 중 전신마사지가 초산부의 자궁수축, 분만소요시간, 분만형태 및 약물사용에 미치는 효과 (Effects of a Full Body Massage on Uterine Contraction, Length of Labor, Type of Delivery, and Drug Intervention for Primipara during Labor)

  • 이군자;장춘자;조현숙;김미란
    • 여성건강간호학회지
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    • 제8권4호
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    • pp.538-549
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    • 2002
  • This study was designed to test the effects of a full body massage on uterine contraction, length of labor, type of delivery, and drug intervention for primipara during labor. Data were collected using a quasi-experiment method (nonequivalent control group, pre-post test design) from November 1, 2001 to July 31, 2002. The subjects of this experiment consisted of 28 women in the experimental group and 29 in the control group, out of 57 primipara hospitalized at the U OB & GYN hospital in Inchon. The experimental group was given a 20 minute full body massage for each of the three delivery phases (latent, active, and transition). The control group was given conventional delivery care. Three (3) parameters were analyzed in this experiment. (1) The interval, duration, and strength of uterine contraction, using an electric tocodynamometer (2) The elapsed time for stage 1 and stage 2 labor. (3) The types of deliveries and drug interventions, using postpartum medical records The data collected were analyzed using the repeated measures analysis of variance (ANOVA), t-test, and $x^2$ test of the SPSS program. The results of the experiment are as follows: 1) Uterine contraction interval was significantly reduced (F=3.210, p=.050). Duration of uterine contraction showed significant increase only during the transition phase (t=-2.319, p=.023). Strength of uterine contraction showed no significant difference. 2) Total length of labor was significantly shortened (t=-5.245, p=.000). The length of 1st stage labor was significantly shortened (t=-5.164, p=.000), with latent phase showing (t=-4.709, p=.000), active phase (t=-2.973, p=.005), and transition phase (t=-2.031, p=.047). The length of 2nd stage labor showed no significant difference. 3) The number of natural deliveries were significantly increased ($x^2$=13.127, p=.004). 4) The number of drug interventions were significantly fewer ($x^2$= 4.493, p=.034). In conclusion, this study shows that a full body massage has a significantly positive effect on uterine contraction interval, length of labor, type of delivery, and drug intervention. Therefore, this study suggests that a full body massage be used clinically to help primipara during labor.

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Binary Compound Formation upon Copper Dissolution: STM and SXPS Results

  • Hai, N.T.M.;Huemann, S.;Hunger, R.;Jaegermann, W.;Broekmann, P.;Wandelt, K.
    • Corrosion Science and Technology
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    • 제6권4호
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    • pp.198-205
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    • 2007
  • The initial stages of electrochemical oxidative CuI film formation on Cu(111), as studied by means of Cyclic Voltammetry (CV), in-situ Scanning Tunneling Microscopy (STM) and ex-situ Synchrotron X-ray Photoemission Spectroscopy (SXPS), indicate a significant acceleration of copper oxidation in the presence of iodide anions in the electrolyte. A surface confined supersaturation with mobile CuI monomers first leads to the formation of a 2D-CuI film via nucleation and growth of a Cu/I-bilayer on-top of a pre-adsorbed iodide monolayer. Structurally, this 2D-CuI film is closely related to the (111) plane of crystalline CuI (zinc blende type). Interestingly, this film causes no significant passivation of the copper surface. In an advanced stage of copper dissolution a transition from the 2D- to a 3D-CuI growth mode can be observed.

A Fundamental Study for Creating 3D CG Animation of an Assembly Work

  • Yamanaka, Hiroki;Matsumoto, Toshiyuki;Shinoda, Shinji;Niwa, Akira
    • Industrial Engineering and Management Systems
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    • 제11권2호
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    • pp.188-195
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    • 2012
  • This paper presents a new mode of expressing a 3D assembly work for creating a 3D CG animation without judgment by human from minimal required information. In the field of manufacturing, there are favorable movements in the utilization of 3D CAD for 3D simulation to shorten lead time for product development and pre-production. But simulating an assembly work has troubles to need huge quantity of manually input data. This paper discusses what minimal necessary information for creating 3D CG animations of assembly works is, focusing on the features of assembly works. Furthermore, a new mode of expressing a 3D assembly work is proposed as "state/change transition diagrams" (SCTD), which express arbitrary scenes in an assembly work as "state" and describe a sequential assembly work with "state" and "change", and the outline of its stepwise generation algorithm is also described. SCTD can be converted to a 3D CG animation of an assembly work without judgment by human. This paper focuses on the creating 3D CG animation of assembly works which workers use only their both hands.

Schottky Barrier Free Contacts in Graphene/MoS2 Field-Effect-Transistor

  • Qiu, Dongri;Kim, Eun Kyu
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.209.2-209.2
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    • 2015
  • Two dimensional layered materials, such as transition metal dichalcogenides (TMDs) family have been attracted significant attention due to novel physical and chemical properties. Among them, molybdenum disulfide ($MoS_2$) has novel physical phenomena such as absence of dangling bonds, lack of inversion symmetry, valley degrees of freedom. Previous studies have shown that the interface of metal/$MoS_2$ contacts significantly affects device performance due to presence of a scalable Schottky barrier height at their interface, resulting voltage drops and restricting carrier injection. In this study, we report a new device structure by using few-layer graphene as the bottom interconnections, in order to offer Schottky barrier free contact to bi-layer $MoS_2$. The fabrication of process start with mechanically exfoliates bulk graphite that served as the source/drain electrodes. The semiconducting $MoS_2$ flake was deposited onto a $SiO_2$ (280 nm-thick)/Si substrate in which graphene electrodes were pre-deposited. To evaluate the barrier height of contact, we employed thermionic-emission theory to describe our experimental findings. We demonstrate that, the Schottky barrier height dramatically decreases from 300 to 0 meV as function of gate voltages, and further becomes negative values. Our findings suggested that, few-layer graphene could be able to realize ohmic contact and to provide new opportunities in ohmic formations.

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