http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 박병우 (검색결과 323 건)
- 무료
- 기관 내 무료
- 유료
-
박병우,신호용,김종호,임종인,Park, B.W.,Shin, H.R.,Kim, J.H.,Im, J.I. 한국결정성장학회 2010 한국결정성장학회지 Vol.20 No.5
Silicon carbide (SiC) ceramics are widely used in the application of high-temperature structural devices due to their light weight as well as superior hardness, fracture toughness, and temperature stability. In this paper, we employed classical molecular dynamics simulations using Tersoff's potential to investigate the elastic constants of the SiC crystal at high temperature. The stress-strain characteristics of the SiC crystal were calculated with the LAMMPS software and the elastic constants of the SiC crystal were analyzed. Based on the stress-strain analysis, the SiC crystal has shown the elastic deformation characteristics at the low temperature region. But the slight plastic deformation behavior was shown as applied the high strain over $1,000^{\circ}C$. Also the elastic constants of the SiC crystal were changed from about 475 GPa to 425 GPa as increased the temperature to $1,250^{\circ}C$. SiC 세라믹스는 가볍고, 우수한 고온 강도 및 온도 안정성을 지니고 있어 고온 구조용 디바이스에 많이 응용되고 있다. 본 논문에서는 분자동역학을 이용하여 다양한 온도에서 SiC 결정의 탄성율 특성을 분석하고자 하였다. 이를 위하여 SiC 결정을 모델링하여 구성 원자 사이에 Tersoff 포텐셜을 적용하고, 분자동역학 프로그램인 LAMMPS S/W를 이용하여 상온부터 $1,250^{\circ}C$까지 응력-변위 거동(stress-strain behavior) 및 탄성율 변화를 분석하였다. 본 연구의 결과, SiC 결정은 잘 알려진 바와 같이 저온에서 탄성변형 특성을 보이지만, $1,000^{\circ}C$ 이상의 고온에서 높은 변위를 인가할 경우, 약간의 소성 변형 특성을 보이는 것으로 나타났다. 또한 상온부터 $1,250^{\circ}C$까지 온도가 증가함에 따라 SiC 결정의 탄성율은 약 475 GPa 부터 425 GPa의 범위에서 변화하는 것으로 분석되었다.
-
-
박병우,정봉식,Park Byung-Woo,Jeong Bong-Sik 한국융합신호처리학회 2005 융합신호처리학회 논문지 (JISPS) Vol.6 No.4
본 논문에서는 GPS(Global Positioning System)용 개구면 결합 소형 RHCP(Right-Handed Circular Polaization) 패치 안테나를 설계하였다. GPS 안테나의 원형분극 특성은 정사각형 패치면의 한 대각선 방향의 양 모서리에 섭동을 부여하여 구현하였고, GPS 안테나의 소형화는 패치면의 네 변의 중심에 일정한 길이의 슬릿을 삽입하여 등가적으로 표면전류의 경로를 증가하는 것으로 구현하였다. 안테나의 급전구조는 단일 급전구조로서 원형분극 안테나의 소형화가 용이하고 상대적으로 넓은 대역폭 특성을 갖는 접지도체에 십자형 개구면을 갖는 개구면 결합구조를 적용하였다. 해석 및 측정 결과, 소형 RHCP 안테나는 소형화 기법을 적용하기 이전에 비해 패치면적을 약 $42.7\%$ 줄였고, 대신-10dB 대역폭과 3dB 축비대역폭은 각각 $56\%,\;38.5\%$ 감소하였다. 또한 제한 구조를 상용 GPS 세라믹 안테나에 적용한 결과, 3dB 축비대역폭이 $56\%$ 줄었지만 패치면적을 $42.9\%$ 줄일 수 있음을 확인하였다. In this paper, the miniaturization of aperture-coupled RHCP patch antenna for the GPS system is treated. Circularly polarization characteristics is implemented by truncating diagonal corners of the square patch. Antenna size is reduced by inserting four uniform slits at the patch edges, which was equivalently lengthened the surface current by meandering it, This antenna uses aperture-coupled feeding structure with crossed-slot shape in order to give easy miniaturization of RHCP patch antenna. Simulated and measured results show that $42.7\%$ lower antenna size is obtained, and also $56\%$ lower -10dB bandwidth and $38.5\%$ lower 3dB AR bandwidth are obtained. when the proposed design scheme is applied to a commercial GPS antenna structure, $42.9\%$ lower patch size and $56\%$ lower 3dB AR bandwidth compared to commercial antenna at the same frequency are obtained.
-
-
Unmet Needs of Breast Cancer Patients Relative to Survival Duration
박병우,황숙연 연세대학교의과대학 2012 Yonsei medical journal Vol.53 No.1
Purpose: The present study aims to evaluate the prevalence of unmet needs among breast cancer survivors, to assess the relationships between unmet needs and depression and quality of life, and to explore the extent to which unmet needs of breast cancer patients relate to the time elapsed since surgery. Materials and Methods: Among 1,250 eligible patients who participated in the study, 1,084 cases (86.7%) were used for analysis. Clinicopathological and social parameters were reviewed and the Supportive Care Needs Survey, Functional Assessment of Cancer Therapy-Breast cancer instrument, and Beck Depression Inventory were administered. The frequency of unmet needs, the association between unmet needs and depression and/or quality of life (QOL) and the impact of the time elapsed since surgery on the patients’ unmet needs were analyzed. Results: The highest levels of unmet needs were found to be in the health system and information domain. Patients with a survival duration of less than 1 year since surgery showed significantly higher unmet needs in all need domains except the sexuality domain (p<0.001) than participants in the other groups. Patients with a survival duration of 1-3 years also experienced significantly higher psychological and information needs than long-term survivors (>5 years). In addition, unmet needs were significantly associated with depression (p<0.001) and QOL (p<0.001). Conclusion: The present study demonstrated that long-term breast cancer survivors had a significantly lower level of unmet needs than patients with survival duration of less than 3 years after surgery and patients with survival duration of less than 1 year since surgery suffered the greatest unmet needs. QOL might be enhanced if interventions are made for specific unmet needs of each patient group.
-
Quality of Life Differences between Younger and Older Breast Cancer Patients
박병우,이수연,이아름,이경희,황숙연 한국유방암학회 2011 Journal of breast cancer Vol.14 No.2
Purpose: This study was designed to investigate quality of life (QOL) differences between younger (<50 years) and older (≥50 years) breast cancer survivors and to determine the unique effect of age on QOL after adjusting age-correlated variables. Methods: One thousand two hundred fifty patients were enrolled. Clinicopatholgical and social parameters were reviewed and Functional Assessment of Cancer Therapy-Breast cancer instrument (FACT-B) and the Ladder of Life scale were used to measure the QOL. Among 1,250 eligible patients, 1,094 patients completed the questionnaire and were used for analysis. Chi-square test, t-test and a series of multiple regression analyses were conducted to verify age-related differences in QOL between two groups and to evaluate the unique contribution of age variable on QOL of breast cancer patients. Results: Significant socio-demographic and clinical differences existed based on age categories, including education, job, time since surgery, chemotherapy and daily activity. Also, there were significant age-related differences in FACT-B total, physical well-being, social/family well-being, functional well-being and breast cancer subscale and in subjective QOL. Older patients ≥50 years showed significantly lower QOL than younger patients <50 years. However, after controlling for age-correlated variables including job, education, time since surgery, chemotherapy, and daily activity, there was no unique age difference in QOL among breast cancer survivors. Conclusion: Our study results suggest that older women with breast carcinoma suffered significantly lower QOL, even though the unique age effect was not found. Therefore, various interventions for enhancing QOL for women with breast carcinoma should be provided to older age group.
-
박병우,황숙연 한국유방암학회 2009 Journal of breast cancer Vol.12 No.3
Purpose: The objective of this study was to investigate the predictors of depression and coping and the correlation between depression and use of coping among breast cancer patients in Korea. Methods: Of 1,250 eligible breast cancer patients attending Yonsei University Severance Hospital, 1,160 completed our surveys. Depression and coping were assessed using the Beck Depression Inventory and Korean Cancer Coping Questionnaire. Socio-demographic characteristics were included in the survey and medical factors were compiled by reviewing each patient’s medical chart. Results: Education, economic status, the level of daily activities, menopause and the type of surgery significantly predicted depression. Age, education, economic status, time since surgery, the level of daily activities, and menopause were significant predictors for personal coping; marriage, education, economic status, time since surgery, the surgical method and radiotherapy significantly predicted interpersonal coping. Personal coping and interpersonal coping had significant negative correlations with depression. Conclusion: Many factors are significant predictors but education and economic status are the most significant and consistent predictors for both depression and coping in breast cancer patients. Psychosocial intervention should be planned according to different characteristics of breast cancer patients, in order to reduce depression and enhance effective coping.
-
Unmet Needs and Their Relationship with Quality of Life among Women with Recurrent Breast Cancer
박병우,황숙연 한국유방암학회 2012 Journal of breast cancer Vol.15 No.4
Purpose: This study aimed to evaluate the prevalence and the effects of unmet needs on quality of life (QOL) among recurrent breast cancer survivors. Methods: Completed questionnaires were collected from 52 women with recurrent breast cancer. Clinical and socio-demographic characteristics were reviewed, and the Supportive Care Needs Survey, Functional Assessment of Cancer Therapy-Breast Cancer Instrument, and Beck Depression Inventory (BDI) were administered. The frequency of unmet needs and the mean differences by patient characteristics and BDI scores were analyzed. The predictive value of unmet needs on QOL, controlling for socio-demographic variables and then for clinical variables, was analyzed in hierarchical regression models. Results: The most common unmet needs belonged to the health system and information domain. The depressive group had greater unmet needs in the psychological domain (p<0.001), physical and daily living domain (p=0.001), and health and information domain (p=0.002). Patients with lower education attainment and those with lower performance status had greater unmet needs in the psychological needs (p=0.002) and in the physical and daily living needs domain (p=0.002), respectively. Unmet needs in the psychological domain (p=0.008), physical and daily living domain (p=0.022), and sexuality domain (p= 0.040) strongly predicted QOL of women with recurrent breast cancer. Conclusion: Unmet needs were strong predictors for QOL among recurrent breast cancer patients. This suggests that QOL of women with recurrent breast cancer is possibly more affected by unmet needs than by patient’s socio-demographic or clinical characteristics. Intervention strategies could be developed based on the identified needs of women with recurrent breast cancer in order to improve their QOL. Further longitudinal and prospective studies will be necessary to confirm the independent impact of unmet needs on QOL.
-
-
ScienceON
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
