• 제목/요약/키워드: A-D relation

검색결과 1,652건 처리시간 0.031초

Relationship of box counting of fractured rock mass with Hoek-Brown parameters using particle flow simulation

  • Ning, Jianguo;Liu, Xuesheng;Tan, Yunliang;Wang, Jun;Tian, Chenglin
    • Geomechanics and Engineering
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    • 제9권5호
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    • pp.619-629
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    • 2015
  • Influenced by various mining activities, fractures in rock masses have different densities, set numbers and lengths, which induce different mechanical properties and failure modes of rock masses. Therefore, precisely expressing the failure criterion of the fractured rock influenced by coal mining is significant for the support design, safety assessment and disaster prevention of underground mining engineering subjected to multiple mining activities. By adopting PFC2D particle flow simulation software, this study investigated the propagation and fractal evolution laws of the micro cracks occurring in two typical kinds of rocks under uniaxial compressive condition. Furthermore, it calculated compressive strengths of the rocks with different confining pressures and box-counting dimensions. Moreover, the quantitative relation between the box-counting dimension of the rocks and the empirical parameters m and s in Hoek-Brown strength criterion was established. Results showed that with the increase of the strain, the box-counting dimension of the rocks first increased slowly at the beginning and then exhibited an exponential increase approximately. In the case of small strains of same value, the box-counting dimensions of hard rocks were smaller than those of weak rocks, while the former increased rapidly and were larger than the latter under large strain. The results also presented that there was a negative correlation between the parameters m and s in Hoek-Brown strength criterion and the box-counting dimension of the rocks suffering from variable mining activities. In other words, as the box-counting dimensions increased, the parameters m and s decreased linearly, and their relationship could be described using first order polynomial function.

아버지의 양육태도 및 관심도와 자녀의 인성과의 상관관계 (A Study on the Relation between Father's Child-Rearing Attitude or Child-Concern and Children's Personality)

  • 이행자
    • 대한가정학회지
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    • 제17권2호
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    • pp.83-105
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    • 1979
  • The purpose of this study is 1) to find out several factors which related to father's rearing attitude and father's concern influencing on children's personality development and 2) to examine closely the correlation between father and children's personality. For the study, cases of 914 children from Seoul and Chong-Ju were sampled to put their personality on test and to investigate on the father's attitude for child rearing and child -concern. The instruments used in this research are question aires, which the investigators made, to examine the father's attitude for child-rearing and child-concern, and the child-personality test performed by Ph. D.B.M.J eong. The results obtained can be summarized as follows : 1. Most fathers were found to be more affectionate to daughters then to sons in their attitude for child-rearing and child-concern , and fathers in Chong-Ju had the tendency to have morn concern about the first child. 2. The more educated fathers, public official or company employee, and Christian or Catholic , showed much more concern about their children, which was shown or Catholic ,showed much more concern about their children , which was shown in this study as statistically significant (P<.0.1, F-test). 3. There were no sex differences in correlations between father's child-rearing attitude or child-concern and child-personality. 4. Father's child-rearing attitude was highly related to child's birth order, That is : the first child showed the low coefficient in general activity and impulsiveness, and showed the high coefficient in emotional stability of personality traits when father's child-rearing attitude was high. 5. Regardless of sex, birth order, economic level, children showed high coefficient in dominance, reflectiveness, and sociability of personality traits when father's child-concern was high. 6. Children in Chong-Ju also presented high marks at percentile in emotional stability when they liked grand fathers and fathers. 7. Children who identify their fathers showed the high marks in emotional stability, specially cases of Chong-Ju were statistically more significant (P<0.5, F-test). 8. There were much difference in percentile marks of personality traits among children in Seoul and Chong -Ju ; the marks which children in Chong-ju made were average 13.71 score lower than those of Seoul in general -activity , dominace, impulsiveness reflectiveness, sociability only except emotional stability.

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CsI(Li) 단결정의 섬광특성 (Scintillation Characteristics of CsI(Li) Single Crystals)

  • 이우교;도시홍;노태익;김완;강희동;문병수
    • 센서학회지
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    • 제8권5호
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    • pp.359-367
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    • 1999
  • CsI에 lithium을 활성제로 0.02, 0.1, 0.2 및 0.3 mole% 첨가한 CsI(Li) 단결정을 Czochralski 방법으로 육성하였다. 육성한 CsI(Li) 단결정의 격자구조는 bcc구조였으며, 격자상수 $a_o$ 값은 $4.568\;{\AA}$이었다. CsI(Li) 단결정의 흡수단은 245 nm이였으며, 흡수단으로 여기 시킨 발광스펙트럼의 파장범위는 $300{\sim}600\;nm$이었고 중심파장은 425 nm이었다. Li 농도를 0.2 mole% 첨가한 경우 에너지 분해능은 $^{137}Cs$(662 keV)에 대해서는 14.5%, $^{54}Mn$(835 keV)에 대해서는 11.4%이었고 $^{22}Na$의 511 keV와 1275 keV에 대한 에너지 분해능은 각각 17.7%와 7.9% 이었다. 그리고, $\gamma$선 에너지와 에너지 분해능 사이의 관계식은 ln (FWHM%) = -0.893lnE + 8.456이였으며, 에너지 교정곡선은 ${\log}E_r=1.455\;{\log}(ch.)-1.277$이었다. Li를 0.2 mole% 첨가한 CsI(Li) 단결정의 인광감쇠시간은 실온에서 0.51 s이었고, 일정비율 시간분석법(CFT:constant-fraction timing method)으로 측정한 시간분해능은 9.0 ns 이었다.

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월경 전후기 증상 정도 및 월경고통 유형 판별요인 (A Study on the Differentiation of Women with Perimenstrual Symptom Severity and Perimenstrual Distress Patterns)

  • 박영주;유호신
    • 여성건강간호학회지
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    • 제4권1호
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    • pp.123-138
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    • 1998
  • The purpose of this study was to describe perimenstrual symptom severity levels and perimenstrual distress patterns of women. The study performed the discriminant analysis in which included seven factors : age, pariety, social support, menstrual socialization(mother's symptom, sister's symptom, and menstrual effect), attitude of sex role and depression. The subjects were 283 women that they were not pregnant or lactating, had at least one period in past three months, would understand the purpose of study and willingly accepted the participation. The data analysis was done by pc-SAS program after data collection from Nov. 20, 1997 to Dec. 18, 1997. The descriptive analysis was done to explore general characteristics of the subjects and the stepwise discriminant analysis was done to verify factors in relation to perimenstrual symptom severity levels(severe vs mild menstrual symptom group) and perimenstrual distress patterns(spasmodic vs congestive menstrual symptom group). The instruments were selected for this study from Interpersonal Support Evaluation List(ISEL) by Cohen and Hoberman(1983), Center for Epidemic Studies Depression(CES-D) by Radloff(1977), and Sex Role Attitude Scale by Yunok Suh(1995), Mother's symptom and sister's symptom measurements by Woods, Mitchell & Lentz(1995), and menstrual effect by Brooks-Gun & Ruble(1980). The major findings of this study are as follows : 1. Of the 283 women, 93 women(32.9%) were assessed to severe perimenstrual symptom group and 190 women(67.1%) were assessed to mild perimenstrual symptom group. Results from the stepwise discriminant analysis showed three factors, such as depression, menstrual effect, and age, significantly related to perimenstrual symptom severity and they explained 20% of the total variance. The linear discriminant equation included three factors related to perimenstrual symptom groups was showed(Z=1.445 depression+0.174 menstrual effect-0.054 age). The cutting score(Z) was 2.809. We classified the severe perimenstrual symptom group by more than the cutting score 2.809 and the mild perimenstrual symptom by less or equal than the cutting score 2.809. The correctedness of posterior probability from discriminant equation was 72% as two perimenstrual symptom group classifications. 2. Of the 264 women, 139 women(52.7%) were assessed to spasmodic perimenstrual distress group and women(47.3%) were assessed to congestive perimenstrual distress group. Results from the stepwise discriminant analysis showed two factors, such as depression, age, significantly related to perimenstrual distress groups and they explained 8% of the total variance. The linear discriminant equation included two factors related to perimenstrual distress group was showed(Z=-0.084 age-0.776 depression). The cutting score(Z) was -3.759. We classified the spasmodic perimenstrual distress group by more than cutting score -3.759 and the congestive perimenstrual distress group by less or equal than cutting score -3.759. The correctedness of posterior probability from discriminant equation was 65% as two perimenstrual distress group classifications.

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연구개발조직 구성원이 인식하는 신뢰, 동료애, 자부심의 영향관계에 대한 실증연구 : GPTW 신뢰지수를 중심으로 (An Empirical Study on Effective Relation among Trust, Camaraderie, and Pride Perceived by Employees of an R&D Institute : on the Basis of GPTW Trust Index)

  • 배재성;서영욱
    • 한국산학기술학회논문지
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    • 제20권6호
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    • pp.565-572
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    • 2019
  • 과학기술 정부출연연구소(출연연)는 정부출연금으로 운영되는 공공 연구기관으로서 우리나라 산업발전 및 과학기술을 선도해왔다. 로버트 레버링은 '일하기 좋은 훌륭한 일터(Great Place to Work; GPTW)'를 본인이 고안한 신뢰지수(Trust Index)로 측정하여 매년 'Fortune 100대 GPTW'를 선정하고 있다. 본 연구의 목적은 GPTW 신뢰지수 5개 요소인 믿음, 존중, 공정성, 동료애, 자부심간의 영향 관계를 분석하고 이들이 GPTW 인식에 어떠한 영향을 미치는 지를 실증 분석하는 것이다. 또한 GPTW 신뢰지수가 'Fortune 100대 GPTW' 선정기준으로 타당한지도 간접적으로 증명하고자 한다. 본 연구는 K 출연연 구성원 262명이 응답한 설문을 분석에 활용하였으며, 수집된 자료의 통계처리는 Smart PLS 2.0과 SPSS 18 프로그램을 활용하였다. 연구결과 믿음은 자부심에, 존중은 자부심과 동료애에, 공정성은 동료애에, 동료애는 자부심에 각각 정(+)의 영향을 미치는 것으로 나타났다. 또한 자부심과 동료애는 구성원이 속한 조직이 GPTW라는 인식에 정(+)의 영향을 미치고 있는 것으로 나타남으로써 로버트 레버링의 신뢰지수가 GPTW 선정지표로서 타당하다는 것을 간접적으로 증명했다. 본 연구는 출연연 구성원들이 인식하는 5개 GPTW 신뢰지수 요소들 간 영향관계를 처음으로 실증분석 했다는 데 큰 의미가 있다. 본 연구는 출연연의 조직성과를 높이기 위해서는 서로 신뢰하고 존중하고 동료애를 발휘하여 자부심을 높여야 한다는 시사점을 제공하고 있다.

병원 간호사의 선호근무시간대에 관한 연구 (A Study on Hoslital Nurses' Preferred Duty Shift and Duty Hours)

  • 이경식;정금희
    • 대한간호
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    • 제36권1호
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    • pp.77-96
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    • 1997
  • The duty shifts of hospital nurses not only affect nurses' physical and mental health but also present various personnel management problems which often result in high turnover rates. In this context a study was carried out from October to November 1995 for a period of two months to find out the status of hospital nurses' duty shift patterns, and preferred duty hours and fixed duty shifts. The study population was 867 RNs working in five general hospitals located in Seoul and its vicinity. The questionnaire developed by the writer was used for data collection. The response rate was 85.9 percent or 745 returns. The SAS program was used for data analysis with the computation of frequencies, percentages and Chi square test. The findings of the study are as follows: 1. General characteristics of the study population: 56 percent of respondents was (25 years group and 76.5 percent were "single": the predominant proportion of respondents was junior nursing college graduates(92.2%) and have less than 5 years nursing experience in hospitals(65.5%). For their future working plan in nursing profession, nearly 50% responded as uncertain The reasons given for their career plan was predominantly 'personal growth and development' rather than financial reasons. 2. The interval for rotations of duty stations was found to be mostly irregular(56.4%) while others reported as weekly(16.1%), monthly(12.9%), and fixed terms(4.6%). 3. The main problems related to duty shifts particularly the evening and night duty nurses reported were "not enough time for the family, " "afraid of security problems after the work when returning home late at night." and "lack of leisure time". "problems in physical and physiological adjustment." "problems in family life." "lack of time for interactions with fellow nurses" etc. 4. The forty percent of respondents reported to have '1-2 times' of duty shift rotations while all others reported that '0 time'. '2-3 times'. 'more than 3 times' etc. which suggest the irregularity in duty shift rotations. 5. The majority(62.8%) of study population found to favor the rotating system of duty stations. The reasons for favoring the rotation system were: the opportunity for "learning new things and personal development." "better human relations are possible. "better understanding in various duty stations." "changes in monotonous routine job" etc. The proportion of those disfavor the rotating 'system was 34.7 percent. giving the reasons of"it impedes development of specialization." "poor job performances." "stress factors" etc. Furthermore. respondents made the following comments in relation to the rotation of duty stations: the nurses should be given the opportunity to participate in the. decision making process: personal interest and aptitudes should be considered: regular intervals for the rotations or it should be planned in advance. etc. 6. For the future career plan. the older. married group with longer nursing experiences appeared to think the nursing as their lifetime career more likely than the younger. single group with shorter nursing experiences ($x^2=61.19.{\;}p=.000;{\;}x^2=41.55.{\;}p=.000$). The reason given for their future career plan regardless of length of future service, was predominantly "personal growth and development" rather than financial reasons. For further analysis, the group those with the shorter career plan appeared to claim "financial reasons" for their future career more readily than the group who consider the nursing job as their lifetime career$(x^2$= 11.73, p=.003) did. This finding suggests the need for careful .considerations in personnel management of nursing administration particularly when dealing with the nurses' career development. The majority of respondents preferred the fixed day shift. However, further analysis of those preferred evening shift by age and civil status, "< 25 years group"(15.1%) and "single group"(13.2) were more likely to favor the fixed evening shift than > 25 years(6.4%) and married(4.8%)groups. This differences were statistically significant ($x^2=14.54, {\;}p=.000;{\;}x^2=8.75, {\;}p=.003$). 7. A great majority of respondents(86.9% or n=647) found to prefer the day shifts. When the four different types of duty shifts(Types A. B. C, D) were presented, 55.0 percent of total respondents preferred the A type or the existing one followed by D type(22.7%). B type(12.4%) and C type(8.2%). 8. When the condition of monetary incentives for the evening(20% of salary) and night shifts(40% of. salary) of the existing duty type was presented. again the day shift appeared to be the most preferred one although the rate was slightly lower(66.4% against 86.9%). In the case of evening shift, with the same incentive, the preference rates for evening and night shifts increased from 11.0 to 22.4 percent and from 0.5 to 3.0 percent respectively. When the age variable was controlled. < 25 yrs group showed higher rates(31.6%. 4.8%) than those of > 25 yrs group(15.5%. 1.3%) respectively preferring the evening and night shifts(p=.000). The civil status also seemed to operate on the preferences of the duty shifts as the single group showed lower rate(69.0%) for day duty against 83. 6% of the married group. and higher rates for evening and night duties(27.2%. 15.1%) respectively against those of the married group(3.8%. 1.8%) while a higher proportion of the married group(83. 6%) preferred the day duties than the single group(69.0%). These differences were found to be statistically all significant(p=.001). 9. The findings on preferences of three different types of fixed duty hours namely, B, C. and D(with additional monetary incentives) are as follows in order of preference: B type(12hrs a day, 3days a wk): day shift(64.1%), evening shift(26.1%). night shift(6.5%) C type(12hrs a day. 4days a wk) : evening shift(49.2%). day shift(32.8%), night shift(11.5%) D type(10hrs a day. 4days a wk): showed the similar trend as B type. The findings of higher preferences on the evening and night duties when the incentives are given. as shown above, suggest the need for the introductions of different patterns of duty hours and incentive measures in order to overcome the difficulties in rostering the nursing duties. However, the interpretation of the above data, particularly the C type, needs cautions as the total number of respondents is very small(n=61). It requires further in-depth study. In conclusion. it seemed to suggest that the patterns of nurses duty hours and shifts in the most hospitals in the country have neither been tried for different duty types nor been flexible. The stereotype rostering system of three shifts and insensitiveness for personal life aspect of nurses seemed to be prevailing. This study seems to support that irregular and frequent rotations of duty shifts may be contributing factors for most nurses' maladjustment problems in physical and mental health. personal and family life which eventually may result in high turnover rates. In order to overcome the increasing problems in personnel management of hospital nurses particularly in rostering of evening and night duty shifts, which may related to eventual high turnover rates, the findings of this study strongly suggest the need for an introduction of new rostering systems including fixed duties and appropriate incentive measures for evenings and nights which the most nurses want to avoid, In considering the nursing care of inpatients is the round-the clock business. the practice of the nursing duty shift system is inevitable. In this context, based on the findings of this study. the following are recommended: 1. The further in-depth studies on duty shifts and hours need to be undertaken for the development of appropriate and effective rostering systems for hospital nurses. 2. An introduction of appropriate incentive measures for evening and night duty shifts along with organizational considerations such as the trials for preferred duty time bands, duty hours, and fixed duty shifts should be considered if good quality of care for the patients be maintained for the round the clock. This may require an initiation of systematic research and development activities in the field of hospital nursing administration as a part of permanent system in the hospital. 3. Planned and regular intervals, orientation and training, and professional and personal growth should be considered for the rotation of different duty stations or units. 4. In considering the higher degree of preferences in the duty type of "10hours a day, 4days a week" shown in this study, it would be worthwhile to undertake the R&D type studies in large hospital settings.

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네덜란드의 혁신클러스터정책과 시사점 (The Innovation Ecosystem and Implications of the Netherlands.)

  • 김영우
    • 벤처혁신연구
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    • 제5권1호
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    • pp.107-127
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    • 2022
  • 본 연구는 네덜란드의 지역별 혁신 클러스터정책을 통해 네덜란드 경제의 성장동인을 찾고자 한다. 전통적으로 농업과 물류중심의 경제구조를 가진 네덜란드는 1990년대 지역 클러스터를 만들면서 첨단 허브 국가로서 역할을 충실하게 해왔고 작은 나라임에도 세계 수출의 7위를 차지하는 등 혁신국가의 이미지를 만드는데 성공했다. 그 바탕에는 혁신을 위한 체계적인 분석 접근법으로 '지역 혁신 시스템(Rational Innovation System)'의 개념을 도입하고 지역의 특색을 살린 산학연 모델이 가장 큰 요인으로 작용했다. 여기에는 적절한 중앙정부의 혁신 생태계 조성을 위한 정책적 방향 제시와 지역을 중심으로 한 산학연 모델이 크게 작용한 것으로 평가받고 있다. 이런 점을 종합적으로 살펴 볼 때 본고에서는 다음과 같은 시사점을 발견할 수 있다. 첫째, 혁신 클러스터의 활성화이다. 둘째, Top 9을 중심으로 한 신산업육성정책과 미래산업 전략을 활성화하고 있다. 셋째, 산학연 협력을 구체화하고 있다. 넷째, 스타트업의 창업을 육성하고 있다. 이를 종합하면 네덜란드는 2019년 설립된 TechLeap은 네덜란드의 기술 생태계를 정량화하고 가속화하는 데 도움을 주는데 자본, 시장 및 인재에 대한 접근성을 개선하기 위한 프로그램 및 이니셔티브를 통해 기술 기업이 확장할 수 있는 최적의 환경을 조성해 네덜란드를 미래의 기술 선도기업들을 위한 보금자리로 만들기 위해 노력하고 있다. 첨단농업과 물류국가로 알려진 네덜란드는 4차 산업혁명시대를 맞이하여 로테르담을 중심으로 하는 물류의 항구에서 ICT 기술을 기반으로 하는 '지식항구(brainport)'로 확장하고 있다. 네덜란드는 물류 국가에서 산업화에 성공했지만 최근 지역혁신 생태계를 만들기 위한 중앙정부의 비전 제시와 지역의 특화산업을 연계한 산학연 클러스터 모델이 가장 큰 디딤돌 역할을 하고 있음을 확인할 수 있다. 네덜란드의 혁신정책은 혁신 클러스터 생태계를 중심으로 지역을 개발하고 일자리 창출과 새로운 산업을 위한 투자를 통해 유럽의 '디지털 관문'으로서 역할에 보다 충실할 것으로 전망된다.

선천성 유미흉의 임상적 고찰과 옥트레오타이드 치료 (A clinical study of congenital chylothorax and octreotide therapy)

  • 오웅건;최경은;김경아;고선영;이연경;신손문
    • Clinical and Experimental Pediatrics
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    • 제51권11호
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    • pp.1172-1178
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    • 2008
  • 목 적: 선천성 유미흉은 림프관의 발달이상이나 분만시 외상으로 림프관에 손상이 가해져 유미가 흉관에 새어 나와 흉강 내에 고이는 것으로 설명되지 않는 태아수종의 흔한 원인이 되기도 한다. 본 연구에서는 산전 진단된 태아수종 중 원인질환이 유미흉으로 밝혀진 6예에 대해서 주산기내력, 임상양상, 진단, 치료 및 결과에 관하여 살펴보고, 장간막 혈류를 줄이는 효과를 갖고 있는 somatostatin 유사체인 octreotide의 사용이 치료에 미치는 영향에 대하여 알아보고자 하였다. 방 법: 2004년 1월부터 2007년 7월까지 3년 6개월간 관동대학교 의과대학 제일병원에서 출생한 27,907명의 신생아 중 태아수종을 동반한 선천성 유미흉으로 진단된 6명의 환아들의 의무기록을 후향적으로 조사하였다. 모유 또는 조제분유 수유전과 후의 흉강천자액을 분석하여 유미흉으로 확진하였고 금식, MCT milk, 인공환기기, 흉관삽입 등의 보존적 치료로 완치되었던 3예와 유미흉이 지속되어 octreotide를 사용했던 3예의 분만 형태, 진단시 검사 소견, 치료 방법, 합병증 및 임상경과를 조사하였다. 결 과: 선천성 유미흉은 0.021%의 발생률을 보였으며, 6예 모두 산전검사에서 양수 과다, 흉막 삼출 및 복수가 관찰되어 태아수종으로 진단되었다. 재태 연령은 33주에서 36주 4일이었고 평균체중은 $3,057{\pm}557g$ (2,200-3,805 g), 아프가 점수 1분 $3.0{\pm}1.1$점(1-4점), 5분 $5.7{\pm}2.0$점(5-7점)으로 모두 제왕절개로 분만하였으며, 흉막삼출은 양측성이 6예, 여아에서 4예가 관찰되었다. 흉강천자액의 분석에서 6예 모두 림프구는 92% 이상이었고, TG는 출생직후 삼출액에서 경관수유 후 유미액으로 바뀌면서 200 mg/dL 이상으로 상승되었다. 인공호흡기, 보존적 치료와 흉관삽입으로 치료하여 이중 3예(50%)가 $26.3{\pm}6.4$일(19-30일) 동안 치료받고 퇴원하였고, 나머지 3예(50%)는 유미흉이 지속되어 octreotide로 치료하였으며 평균 입원기간은 $57.7{\pm}16.2$일(39-68일)이었다. Octreotide는 평균 $18{\pm}9$일 동안 1-10 mcg/kg/hr 주입속도로 정맥내 주사하였으며, 3명 모두 완치 후 퇴원하였다. 외과적 치료가 필요하였던 환아는 없었으며, 치료 중 기흉 1명, 저알부민혈증 2명이 관찰되었고, octreotide 사용시에 1예에서 경한 구토증상만 보였지만 다른 부작용은 관찰되지 않았다. 결 론: 본 연구결과와 같이 octreotide는 보존적 치료에 잘 치료되지 않는 선천성 유미흉에 대해서 좋은 치료약제로 고려될 수 있을 것이다. 그러나, octreotide 치료의 주입방법, 용량, 치료시작 및 사용기간 등에 대한 정확한 가이드라인이 정립되어 있지 않으므로 이에 대한 연구가 더 필요할 것이며, 또한 octreotide의 좀 더 빠른 치료시작시기가 치료결과에 어떤 영향을 끼치는지에 대해서도 더 많은 연구가 필요할 것으로 사료된다.

Can high serum anti-M${\ddot{u}}$llerian hormone levels predict the phenotypes of polycystic ovary syndrome (PCOS) and metabolic disturbances in PCOS patients?

  • Hwang, Yu Im;Sung, Na Young;Koo, Hwa Seon;Cha, Sun Hwa;Park, Chan Woo;Kim, Jin Yeong;Yang, Kwang Moon;Song, In Ok;Koong, Mi Kyoung;Kang, Inn Soo;Kim, Hye Ok
    • Clinical and Experimental Reproductive Medicine
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    • 제40권3호
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    • pp.135-140
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    • 2013
  • Objective: To evaluate correlations between serum anti-M${\ddot{u}}$llerian hormone (AMH) levels, phenotypes of polycystic ovary syndrome (PCOS), obesity, and metabolic parameters in patients with PCOS. Methods: A total of 175 patients with PCOS were diagnosed according to the Rotterdam Consensus were included. Exclusion criteria were age over 40, FSH>25 mIU/mL, and 17a-OHP>1.5 ng/mL. The Phenotypes of PCOS were divided into a severe form (oligo-anovulation, ANOV/hyperandrogenism/polycystic ovary morphology [PCOM]; n=59) and a mild form without HA (ANOV/PCOM, n=105). The serum AMH levels were classified into 3 groups (<5 vs. 5-10 vs. >10 ng/mL). Obesity was defined as body mass index (BMI) ${\geq}25kg/m^2$ (n=34). Results: The mean age was $25.9{\pm}5.7$ year and mean AMH level was $10.1{\pm}5.4$ ng/mL. The BMI ($kg/m^2$) was higher in group 1 ($24.2{\pm}6.3$) than in group 2 ($21.9{\pm}4.3$, p=0.046) or group 3 ($21.6{\pm}3.3$, p=0.019). There was no difference among the three groups in age, menstrual interval, antral follicle counts, androgens, or other metabolic parameters. The obesity group showed significantly lower AMH ($7.7{\pm}3.9$ ng/mL vs. $10.7{\pm}5.6$ ng/mL), p=0.004) and low-density lipoprotein levels ($93.1{\pm}21.2$ mg/dL vs. $107.5{\pm}39.3$ mg/dL, p=0.031), and showed higher total T ($0.74{\pm}0.59$ L vs. $0.47{\pm}0.36$ ng/mL, p=0.001), free T ($2.01{\pm}1.9$ vs. $1.04{\pm}0.8$ pg/mL, p=0.0001), and free androgen index ($6.2{\pm}7.9$ vs. $3.5{\pm}3.0$, p=0.003). After controlling for age factors and BMI, the serum AMH levles did not show any significant correlations with other hormonal or metabolic parmeters. Conclusion: For PCOS patients under the age 40, serum AMH is not negatively correlated with age. High serum AMH levels can not predict the phenotype of PCOS and metabolic disturbances in PCOS patients in the non-obese group. Further study might be needed to define the relation more clearly.

라만증폭기의 효율적인 성능분석을 위한 라만방정식의 적분형 전개와 수치해석 알고리즘 (Closed Integral Form Expansion for the Highly Efficient Analysis of Fiber Raman Amplifier)

  • 최락권;박재형;김필한;박종한;박남규
    • 한국광학회지
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    • 제16권3호
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    • pp.182-190
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    • 2005
  • 본 논문은 효율적으로 라만 증폭기의 이득을 예측하고 잡음 특성을 분석하기 위해서 라만 증폭기 상관된 상미분방정식 (Ordinary Differential Equation: ODE)을 유효거리(Effective Length) 기반의 상관된 적분형(closed integral form)방정식 및 매트릭스로 전개하고 이 전개를 활용한 라만 증폭기 모델링 및 수치해석 알고리즘을 기술한다. 광섬유 라만 증폭기는 유연하고 넓은 이득 대역폭 및 낮은 잡음 등의 장점 때문에 최근 광통신 시스템에서 핵심기술로 각광받고 있으며, 특히 멀티채널 펌핑구조에서 성능예측을 위해 많은 라만 증폭기 모델링 방법들이 연구되어 왔다. 그러나 기존의 많은 연구들은 라만 증폭기 상관된 상미분방정식의 해를 "fiber propagation axis"를 기반으로 구해왔기 때문에 광섬유 길이에 의존적이고 복잡한 계산으로 상당히 많은 시간이 필요했으며, 실제 전송 시스템에서의 활용이 어려웠다. 이러한 문제점을 해결하기 위해서 본 논문에서는 기존의 상관된 상미분방정식을 접근이 용이한 "유효거리" 기반의 적분형 방정식으로 전개하고 매트릭스 및 벡터 형태로 알고리즘을 공식화하여 빠른 라만 이득 계산과 "iteration axis"를 이용한 해의 도출을 통해 새로운 라만 증폭기 모델링 방법과 수치해석 알고리즘을 제시하였다. 제안한 수치해석 알고리즘을 전방, 후방 및 양방향 펌핑구조의 라만 증폭기가 도입된 시스템에 적용하는 컴퓨터 모의실험을 수행한 결과 기존의 "Average power method와 비교하여 라만 이득과 광선로 내의 펌프 및 신호 광의 진행정도를 18배 이상의 정밀도에서 0.03 dB 이내의 매우 작은 오차범위 및 100배 이상 단축된 짧은 시간으로 정확히 예측하였다. 또한, 수치해석 알고리즘을 통해서 얻은 신호 광 파워의 분포를 바탕으로 Amplified Spontaneous Emission(ASE), 후방 ASE의 레일레이 산란 및 신호의 이중 레일레이 산란과 같은 라만 증폭기 잡음 요소들을 분석하였다. 새롭게 제안한 수치해석 알고리즘은 실제 광통신 시스템에 적용되어 신속하고 효율적으로 라만 증폭기 성능을 예측하고 분석할 수 있을 것으로 기대된다.