• 기본간호학회지
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• 제25권2호
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• pp.120-133
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• 2018

Purpose: A meta-analysis was conducted to evaluate effectiveness of education programs using video recording and feedback in the improvement of competency in clinical skills for health care majors. Methods: Six databases were searched and inclusion criteria were randomized controlled trials (RCTs) or non-randomized controlled trials (NRTs) reporting level of skill competency using numerical measurements. Data analysis and synthesis were performed using Comprehensive Meta-Analysis software and Revman program. Results: Of 1,568 records, 11 studies met inclusion criteria. Statistically significant effectiveness of education programs using video recording and feedback was identified. A low risk of bias was detected among both RCTs and NRTs. Meta-analysis showed that the intervention groups had more effective improvements in skill competency (standardized mean difference [SMD]: 0.74; 95% CI: 0.33~1.16). Results of subgroup analysis showed higher effects when interventions dealt with one skill, used self-reflection with expert feedback, and included instruction from instructor in the education programs. Conclusion: Findings suggest that schools for health care majors should actively adopt video and feedback based skill training allowing educators to design effective programs. Potential is higher for students to achieve higher competency when they train with one skill at a time, use of instruction and receive feedback from experts.

• 한국초등과학교육학회지:초등과학교육
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• 제39권4호
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• pp.506-521
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• 2020

This study aims to develop a scientific creativity task which science-gifted elementary students can conduct on a field trip to a botanical garden, and to analyze the results from conducting the task. For this, 38 science-gifted fifth-graders from the Science-Gifted Education Center, located at the Office of Education, participated in a field trip to a botanical garden, as a part of their program. Prior to the program, researchers developed a scientific creativity task for outdoor education program, along with science education specialists and teachers. The tasks were to observe plants, and to create something new and useful, or, in other words, scientifically creative, based on the plants' characteristics. The students could submit at most three ideas. Also, they assessed their own ideas, and selected an idea that they thought was the most creative. The results were analyzed by using the scientific creativity formula. The main findings from this study are as follows. First, it was found that the scientific creativity formula had an upward bias in assessing originality. Second, the students tended to assess the usefulness of their own ideas more generously. Third, the correlation between self-assessment results and scores from the scientific creativity formula for originality was r=.43. Fourth, in formula-based assessments, the correlation between originality scores and usefulness scores was relatively high, at r=.56. Fifth, the correlation between a student's scientific creativity score and the number of his or her ideas was very low, at r=.23. Sixth, when the ideas chosen as the most creative by students were compared with the ideas that had the highest scores in formula-based assessments, it was shown that 8 out of 19 students (42.1%) did not choose the idea that appeared to be the most creative when graded by the formula. This study is concluded by discussing the lessons from the scientific creativity task analysis for primary science education and gifted education.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1446-1449
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• 1996

Thin films of diamond-like carbon(DLC) have been deposited using a magnetron plasma-enhanced chemical vapor deposition(PECVD) method with an rf(13.56 MHz) plasma of $C_{3}H_{8}$. From the Langmuir probe I-V characteristics, it can be observed that increasing the magnetic field yields an increase of the temperature($T_e$) and density($N_e$) of electron. At a magnetic field of 82 Gauss, the estimated values of $T_e$ and $N_e$ are approximately $1.5\;{\times}\;10^5$ K(13.5 eV) and $1.3\;{\times}\;10^{11}\;cm^{-3}$, respectively. Such a highly dense plasma can be attributed to the enhanced ionization caused by the cyclotron motion of electrons in the presence of a magnetic field. On the other hand, the negative dc self-bias voltage($-V_{sb}$) decreases with an increasing magnetic field, which is irrespective of gas pressure in the range of $1{\sim}7$ mTorr. This result is well explained by a theoretical model considering the variation of $T_e$. Deposition rates of DLC films increases with a magnetic field. This may be due to the increased mean free path of electrons in the magnetron plasma. Structures of DLC films are examined by using various techniques such as FTIR and Raman spectroscopy. Most of hydrocarbon bonds in DLC films prepared consist of $sp^3$ tetrahedral bonds. Increasing the rf power leads to an enhancement of cross-linking of carbon atoms in DLC films. At approximately 140 W, the maximum film density obtained is about 2.4 $g/cm^3$.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.2179-2184
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• 2012

Introduction and aim: To compare reproductive factor influence on patients with pathological diagnosed malignant and benign tumor in the Breast Department, The First Peoples' Hospital of Kunming in Yunnan province, China. Methods: A hospital-based case-control study was conducted on 263 breast cancer (BC) cases and 457 non-breast cancer controls from 2009 to 2011. The cases and controls information on demographics, medical history, and reproductive characteristics variables were collected using a self-administered questionnaire and routine medical records. Histology of breast cancer tissue and benign breast lesion were documented by pathology reports. Since some variables in data analysis had zero count in at least one category, binomial-response GLM using the bias-reduction method was applied to estimate OR's and their 95% confidence intervals (95% CI). To adjust for age and menopause status, a compound variable comprising age and menopausal status was retained in the statistical models. Results: multivariate model analysis revealed significant independent positive associations of BC with short menstrual cycle, old age at first live birth, never breastfeeding, history of oral contraception experience, increased number of abortion, postmenopausal status, and nulliparity. Categorised by age and menopausal status, perimenopausal women had about 3-fold and postmenopausal women had more than 5-fold increased risk of BC compared to premenopausal women. Discussion and Conclusion: This study has confirmed the significant association of BC and estrogen related risk factors of breast cancer including longer menstrual cycle, older age of first live birth, never breastfeeding, nulliparity, and number of abortions more than one. The findings suggest that female hormonal factors, especially the trend of menopause status play a significant role in the development of BC in Yunnan women.

• 대한간호학회지
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• 제43권2호
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• pp.225-235
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• 2013

Purpose: This prospective cohort study was done to investigate recall bias to antepartum variables measured at postpartum periods and predictors of postpartum depression. Methods: Participants were 215 women who answered a self-administered questionnaire which included demographics, Postpartum Depression Predictors Inventory-Revised and Korean version of Edinburgh Postpartum Depression Scale at antepartum 36-40 weeks and postpartum 2 weeks and 6 weeks. Data were analyzed using kappa, and hierarchical multiple logistic regression. Results: Agreement between antepartum variables at both antepartum and two postpartum periods was relatively high (${\kappa}$=.55- .95). Postpartum depression rates were 36.3% and 36.7% at two follow-up points. In hierarchical multiple logistic regression analysis, prenatal depression (OR=4.32, 95% CI: 1.41-13.19; OR=5.19, 95% CI: 1.41-19.08), social support (OR=1.40, 95% CI: 1.18-1.66; OR=1.27, 95% CI: 1.06-1.53) and maternity blues (OR=4.75, 95% CI: 1.89-11.98; OR=4.22, 95% CI: 1.60-11.12) were commonly associated with postpartum depression at two follow-up points. Child care stress (OR=1.85, 95% CI: 1.01-3.37) was only associated with postpartum depression at 2 weeks postpartum and pregnancy intendedness (OR=1.57, 95% CI: 1.09-2.27) was only associated with postpartum depression at 6 weeks postpartum. Conclusions: The results indicate a need to apply nursing interventions such as prenatal education and counseling with families from antenatal period.

• 한국항해학회지
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• 제25권1호
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• pp.53-60
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• 2001

본 논문에서는 IMT-2000 수신주파수인 2.13~2.16 GHz 대역에서 초고주파용 수신장치로 사용되는 저잡음증폭기를 ㅈㄱ렬 피드백 기법과 저항결합회로를 이용하여 구현하였다. GaAs FET(Field Effect Transistor)의 소스단에 부가한 직렬 피드백은 저잡음증폭기의 저잡음특성과 입력반사계수가 작아졌으며, 또 저잡음증폭기의 안정도도 개선되었다. 저항결합회로는 반사되는 전력이 정합 회로내의 저항에서 소모되므로 입력단정합이 용이하였다. 저잡음증폭기의 저잡음증폭단은 GaAs FET인 ATF-10136, 고득증폭단은 내부정합된 MMIC인 VNA-25를 사용하였으며, 알루미늄 기구물 안에 유전율 3.5인테프론 기판에 초고주파회로와 자기바이어스 회로를 함께 장착시켰다. 이렇게 제작된 저잡음증폭기는 30 dB이상의 이득, 0.7dB 이하의 잡음지수, 17 dB의 Pldb, 1.5 이하의 입출력 정재파비를 얻었다.

• The Journal of Korean Physical Therapy
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• 제22권2호
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• pp.69-75
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• 2010

Purpose: The purpose of this study was to investigate the relationship between subjective quality of life and job stress with regard to general characteristics and health characteristics of physical therapists (PTs) and occupational therapists (OTs). Methods: The study involved administering questionnaires to 93 PTs and OTs who worked in urban medical institutions between November 2009 and October 2009. A questionnaire (KvSBQOL) developed by Dunbar and colleagues and translated into Korean version by Yoon et al was used for measuring subjective quality of life. A questionnaire developed by Kim was used for measuring job stress. Results: Among PTs and OTs, the mean quality of life score was 3.10 points and the mean level of job stress was 3.42. Female PTs and OTs had significantly greater levels of job stress. Those PTs and OTs in the 'Lowest pay' group and in the 'Associated Degree' group reported the lowest quality of life. Those in the 'Very healthy' group of PTs and OTs had significantly lower job stress than the other groups. The group with the highest job stress had the lowest quality of life. A limitation of this study was that all data was self-reported and subject to associated bias. Conclusion: To prevent loss of business services by PTs and OTs, it is important to know how job stress affects quality of life. Our findings suggest that a reduction in job stress can improve quality of life among PTs and OTs.

• 한국진공학회지
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• 제13권4호
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• pp.157-163
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• 2004

라디오파 플라즈마 화학증착법 (radio frequency plasma assisted chemical vapor deposition: r.f.-PACVD) 법으로 증착된 다이아몬드성 카본 (Diamond-like Carbon : DLC) 필름에서 나타나는 습도에 따른 압축 잔류 응력의 변화 거동을 체계적으로 조사하였다. 합성에 사용된 탄화수소 가스의 종류와 -100V에서 -800V 범위의 기판 바이어스 전압의 조절을 통해 폴리머성 필름에서 흑연성 필름까지 광범위한 구조의 DLC 필름을 합성하였다. 상대습도가 10％-90％ 범위에서 변화하는 분위기 챔버 내에서 박막의 잔류응력의 변화를 실시간으로 측정하였다 박막의 경도와 잔류응력이 최고 값을 가지는 합성조건에서 얻어진 치밀한 DLC박막에서는 습도에 따른 잔류응력의 변화가 관찰되지 않았다. 그러나, 폴리머상이나 흑연상의 박막에서는 두 경우 모두 습도가 높아짐에 따라 압축 잔류응력이 증가함을 관찰할 수 있었으며, 습도의 변화에 대해 잔류응력이 즉각적으로 변화하였다. 한편, 동일한 습도에서 압축 잔류응력의 증가량은 필름의 두께에 반비례하는 것이 관찰되었다. 이 결과는 물분자가 필름의 구조내로 침투하면서 생기는 변화가 아니라, 박막의 표면에서 일어나는 물분자와의 반응에 의해 필름의 잔류응력이 변할 수 있음을 의미한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.285-285
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• 2011

EUVL (Extreme Ultra Violet Lithography) is one of competitive lithographic technologies for sub-30nm fabrication of nano-scale Si devices that can possibly replace the conventional photolithography used to make today's microcircuits. Among the core EUVL technologies, mask fabrication is of considerable importance since the use of new reflective optics having a completely different configuration compared to those of conventional photolithography. Therefore new materials and new mask fabrication process are required for high performance EUVL mask fabrication. This study investigated the etching properties of SnO2 (Tin Oxide) as a new absorber material for EUVL binary mask. The EUVL mask structure used for etching is SnO2 (absorber layer) / Ru (capping / etch stop layer) / Mo-Si multilayer (reflective layer) / Si (substrate). Since the Ru etch stop layer should not be etched, infinitely high selectivity of SnO2 layer to Ru ESL is required. To obtain infinitely high etch selectivity and very low LER (line edge roughness) values, etch parameters of gas flow ratio, top electrode power, dc self - bias voltage (Vdc), and etch time were varied in inductively coupled Cl2/Ar plasmas. For certain process window, infinitely high etch selectivity of SnO2 to Ru ESL could be obtained by optimizing the process parameters. Etch characteristics were measured by on scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses. Detailed mechanisms for ultra-high etch selectivity will be discussed.

• 대한전자공학회논문지SD
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• 제37권8호
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• pp.42-47
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• 2000

분자선결정성장법을 이용하여 자기구성 양자점들을 high electron mobility transistor (HEMT)의 체널 영역에 삽입하여, 양자점내의 inter-subband transition을 이용한 전파장 적외선 수광소자를 제작하였다. 제작된 소자는 180 K 이상의 온도에서 InAs 양자점의 전자에 대한 강한 구속력으로 인해 낮은 암전류 특성을 보이며 7${\mu}m$에서 11${\mu}m$까지의 넓은 수광영역을 나타내었다. 9.4${\mu}m$에서 peak 광전류가 검출되었으며 이때의 검출율은 $1.93{\times}10^{10}cmHz^{1/2}/W$ 였다. 장파장 적외선 검출에 따른 광전류는 가해진 전압에 대하여 전계효과트랜지스터와 같은 전류-전압 특성을 가지며, 인가된 전압이 증가함에 따라 증가된 암전류에 의하여 광전류가 감소하는 특성을 보여주고 있다.