• 제목/요약/키워드: Analysis & Design

검색결과 49,102건 처리시간 0.086초

신생아집중간호단위 환경과 저체중출생아의 반응에 대한 연구 (A Study on the Environment for Lowbirth Weight Infants in Neonatal Intensive Care Unit in the United States)

  • 한경자
    • Child Health Nursing Research
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    • 제4권2호
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    • pp.159-176
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    • 1998
  • In effort to conduct comparative study on the caregiving environment of Neonatal Intensive Care Unit(NICU) in both U. S and Korea, this study was been conducted first in the U.S. Purpose : The purpose of this study is to identify the physical environment and direct caregiving practices to lowbirth weight infants in NICU in the US. It also aims to examine the NICU outcome status and behavioral reponses of lowbirth weight infants. Methods : A study design using descriptive and inferential statistics was been conducted through an observational, field method. A sample of 15 preform infants admitted to NICU were recruited for the study. The subjects were those with birth weight between 1,000 gm to 1,500 gm, born at the gestation period of 27 to 33 weeks, and without any chromosomal or other genetic anomalies, major congenital infections, or maternal illness. Thirty minutes observation(three times of ten minutes of continuous observation)of the infant's behavior and physiological status, and an four-hour observation of the physical environment and direct care giving procedures were been conducted on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. The data to be collected were in four areas : the demograghic characteristics of the infants, the physical environment and care giving procedures, the frequency of the infant's designated behavior and physiological response, and NICU outcome variables. A descriptive analysis and Kruskal-Wallis, Pearson r were been applied according to variable characteristics. Results : 1. Mother's mean age was 29.47. The sample consisted of 6 males and 9 females. Mean gestational ages were 29.17 weeks. Mean birth weight was 1236.33g. Mean Apgar scores at one minute were 6.6, and 7.8 at five minutes. 2. The location for the incubator was in the distance from the light, X-ray screens and nursing station, in proximity to side-lamp, telephone and faucet on the third day after birth. The location for the incubator was in the distance from the light and radio on the tenth day and in proximity to nursing station on the day of dischage from the NICU or at 34weeks postconception. 3. Nesting was the most applying aids to the infants. And foot roll, shielding and plastic frame were frequently using by nurses for facilitating well modulated restful posture. 4. There were statistically significant changes in the patterns of physical environment included locating the infant's incubator and bedding, specific aids to self regulation on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. 5. Statistically significant changes were not appeared in the patterns of direct caregiving procedure to the infants included stress inducing or reducing manipulations on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. 6. The stress response of the infants in NICU were significantly reduced as the infants grow older. 7. There were not statistically significant correlation between the physical envronment and the stress responses of the infants in NICU. 8. There were statistically significant correlation between the direct caregiving procedure to the infants and the stress response of the infants in NICU in the second and third observation on the day three. 9. Average weight gain per day from birth to discharge was 38.73g, number of days in the hospital was 42.60, number of days before bottle feeding was 3.6. Postconception age starting bottle feed ing was 31/sup +5/ weeks. Number of days on mechanical ventilator was average 7.64, 11.42 was an average number of days of oxygen need. Conclusion : It, thus, appears that to minimize the sensorymotor stimulation for the low birthweight preterm infant in NICU, manipulation of care giving practices to the babies whatever the stress inducing or reducing procedures, have to be limited in the immediate early stage after birth. And it needed to be reexamine to identify the appropriate and specific physical environment and the patterns of direct caregiving to the low birthweight preform infant as the infants grow older in NICU.

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중국 간호교육관련 연구실태 분석 (An Analysis of Nursing education Research in China : 1990-1998)

  • 고일선;이춘옥;김경애
    • 한국간호교육학회지
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    • 제5권2호
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    • pp.177-190
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    • 1999
  • This study has been conducted on the basis of the literature review of Nursing Education Research in China from 1990 through August 1998. Its purpose was to support the basic data of nursing education which is risen as major revolutionary of nursing in China and those for exchange of information between Korea-China nursing education. It is retrospective and descriptive research analyzing one hundred eighty articles published in The Journal of China Nursing. The results of the study were as follows. 1. Only 33.3% of the professors of Technical Nursing School who have played of major role of nursing education in China have carried out the study related to nursing education. Baccalaureate program professors have marked 22.2% of all studies, and diploma program professors have done 12.2% of all. Therefore, the professors of above the diploma program have done total 44.4%. It explains that the professors of baccalaureate and diploma programs have done more studies related to nursing education than those of Technical Nursing School. 2. In terms of the study design, most of the studies(38.8%) were case studies introducing the curriculum contents that were done at education institutions. And then, 28.5% were reviewing the articles, and 15.6% were descriptive studies. 3. In terms of the content of the study, 38.3% were relevant to education of Technical Nursing School, 15.0% were about baccalaureate education, and 10.4% is about diploma. 4. To analyze the specific contents of the studies ; a. In baccalaureate program, human resources (professor or teaching), course extension, lab, classes, teaching method, education philosophy, goal of education, evaluation method, and human resource development were included. b. In diploma program, teaching contents evaluation method, teaching method, and educational system were included c. In the technical school, there were qualification of professors , teaching method, evaluation method, opening the courses, teaching contents, goal of education and so on. d. Beyond these, there were practice guidance and appraisement, teaching method, and opening new courses which were not specially indicated as educational curriculum and score management as continuing education. What is above tell us that the study regarding development of university system has been progressed actively and widely. It has been for the effort of revolution which based on the China government force to reform of nursing education process during last 10 years. On the base of the result, we suggest the following questions and the alternatives. 1) Since most articles are case studies related to teaching methods and the others doesn't propose the research method. the study which is applied more exact research method is needed. 2) No study is regarding social change and health policy. Because University program, founded in 1983 is on the beginning point, the research about curriculum have to be taken as a top priority as well as to reflect social needs which are based on social changes and national health policy 3) Only one review article study tells nursing Human resource. To appear in large numbers in nursing manpower, avoid the present hospital nurses training system. Then, the study for manpower development which is able to accomplish in many fields has to be advanced. 4) Most studies did not have literature review processes, so it was impossible for researcher to know the past study tendency and there is no relation among studies as to same subject, the education about research method is needed.

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인터넷 커뮤니티에서 사용자 참여가 밀착도와 지속적 이용의도에 미치는 영향 (A Study on the Effects of User Participation on Stickiness and Continued Use on Internet Community)

  • 고미현;권순동
    • Asia pacific journal of information systems
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    • 제18권2호
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    • pp.41-72
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    • 2008
  • The purpose of this study is the investigation of the effects of user participation, network effect, social influence, and usefulness on stickiness and continued use on Internet communities. In this research, stickiness refers to repeat visit and visit duration to an Internet community. Continued use means the willingness to continue to use an Internet community in the future. Internet community-based companies can earn money through selling the digital contents such as game, music, and avatar, advertizing on internet site, or offering an affiliate marketing. For such money making, stickiness and continued use of Internet users is much more important than the number of Internet users. We tried to answer following three questions. Fist, what is the effects of user participation on stickiness and continued use on Internet communities? Second, by what is user participation formed? Third, are network effect, social influence, and usefulness that was significant at prior research about technology acceptance model(TAM) still significant on internet communities? In this study, user participation, network effect, social influence, and usefulness are independent variables, stickiness is mediating variable, and continued use is dependent variable. Among independent variables, we are focused on user participation. User participation means that Internet user participates in the development of Internet community site (called mini-hompy or blog in Korea). User participation was studied from 1970 to 1997 at the research area of information system. But since 1997 when Internet started to spread to the public, user participation has hardly been studied. Given the importance of user participation at the success of Internet-based companies, it is very meaningful to study the research topic of user participation. To test the proposed model, we used a data set generated from the survey. The survey instrument was designed on the basis of a comprehensive literature review and interviews of experts, and was refined through several rounds of pretests, revisions, and pilot tests. The respondents of survey were the undergraduates and the graduate students who mainly used Internet communities. Data analysis was conducted using 217 respondents(response rate, 97.7 percent). We used structural equation modeling(SEM) implemented in partial least square(PLS). We chose PLS for two reason. First, our model has formative constructs. PLS uses components-based algorithm and can estimated formative constructs. Second, PLS is more appropriate when the research model is in an early stage of development. A review of the literature suggests that empirical tests of user participation is still sparse. The test of model was executed in the order of three research questions. First user participation had the direct effects on stickiness(${\beta}$=0.150, p<0.01) and continued use (${\beta}$=0.119, p<0.05). And user participation, as a partial mediation model, had a indirect effect on continued use mediated through stickiness (${\beta}$=0.007, p<0.05). Second, optional participation and prosuming participation significantly formed user participation. Optional participation, with a path magnitude as high as 0.986 (p<0.001), is a key determinant for the strength of user participation. Third, Network effect (${\beta}$=0.236, p<0.001). social influence (${\beta}$=0.135, p<0.05), and usefulness (${\beta}$=0.343, p<0.001) had directly significant impacts on stickiness. But network effect and social influence, as a full mediation model, had both indirectly significant impacts on continued use mediated through stickiness (${\beta}$=0.11, p<0.001, and ${\beta}$=0.063, p<0.05, respectively). Compared with this result, usefulness, as a partial mediation model, had a direct impact on continued use and a indirect impact on continued use mediated through stickiness. This study has three contributions. First this is the first empirical study showing that user participation is the significant driver of continued use. The researchers of information system have hardly studies user participation since late 1990s. And the researchers of marketing have studied a few lately. Second, this study enhanced the understanding of user participation. Up to recently, user participation has been studied from the bipolar viewpoint of participation v.s non-participation. Also, even the study on participation has been studied from the point of limited optional participation. But, this study proved the existence of prosuming participation to design and produce products or services, besides optional participation. And this study empirically proved that optional participation and prosuming participation were the key determinant for user participation. Third, our study compliments traditional studies of TAM. According prior literature about of TAM, the constructs of network effect, social influence, and usefulness had effects on the technology adoption. This study proved that these constructs still are significant on Internet communities.

유방 자가 검진 참여 교육 프로그램이 유방 자가 검진 이행과 건강 증진 행위에 미치는 영향 (The Effects of the Breast Self-Examination Participant Education program on Breast Self-Examination Compliance and Health Promoting Behaviors in Adult Women)

  • 박은하;류은정;최경숙
    • 종양간호연구
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    • 제3권2호
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    • pp.133-144
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    • 2003
  • This study is carrying out a before and after experiment design for the non-equal comparative group to identify the effects of the breast self-examination education on breast self-examination participant education compliance and health promotion in women. The subject of this study was 58 women residing in Chungju. Their age ranged from 20 to 40. These women were not pregnant or did not breast feed, as well as they did not have any breast disease, at the time of survey. They were available for the response to the questionnaires, and understood the purpose of this study. They also agreed to participate in the study, and responded to the 3rd time questionnaires to the end. Thus, brochures and lectures were provided side by side to a group of 19 of those women, and only brochures were provided to another group of 39 of those women. With regard to education, a brochure and a program using a breast model were applied. Then, the frequency of the breast self examination compliance, breast self examination capability and the relations between the breast self examination and activities to promote health were measured, before the education, after 4 weeks of education and after 12 weeks of education. Before education and after 4 weeks of education. I collected the questionnaires myself visiting them, and after 12 weeks of education, the questionnaires were collected by mail. In relation to the study tool, the breast self examination activity was measured by two measuring tools: breast self examination activity frequency and breast self examination compliance capability. As for the frequency, the number of self examination for the period of 3 months, before the questionnaire survey, was measured in the form of self report. In relation to the tool to measure the breast self examination capability, the BSEPRI tool, which was developed by Wood in 1994, was used. Here, as the score was higher, the capability was indicated to be higher. The translated and revised version of Health Promoting Lifestyle Profile II (Walker, Sechrist & Pender. 2002) was used as a tool for health promotion. As the measured score was higher, the health promoting activity was indicated to be higher. The results of this study were as follows: 1. As a result of checking the breast self examination compliance frequency between the experiment group that received the breast self examination participant education and the comparative group that did not receive the education, there was a significant difference in interaction between groups by time, as time passed by. 2. As a result of checking the breast self examination compliance capability between the experiment group and the comparative group, there was a significant difference in interaction between groups by time, as time passed by. 3. As a result of carrying out a repetitive measurement analysis, between the experiment group that received the breast self examination education and the comparative group that did not receive the education, which was carried out to validate the hypothesis that the former would have higher health promoting activities than the latter, there was no significant difference after the breast self examination education was conducted.

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차광수준이 곰취 유묘의 생장 및 형태적 특성에 미치는 영향 (Effect of Shading Level on Growth and Morphological Characteristics of Ligularia fischeri Seedling)

  • 송기선;전권석;김창환;윤준혁;박용배;김종진
    • 생물환경조절학회지
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    • 제23권2호
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    • pp.88-94
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    • 2014
  • 본 연구는 기능성 산채로서 수요가 확대되고 있는 곰취를 포장에서 본격적으로 생산하는데 필요한 이식용 유묘를 생산하는 과정에서 차광처리가 반음지식물인 곰취 유묘의 초기 생장에 어떠한 영향을 미치는지 알아보고자 실시하였다. 실험은 차광수준(전광 및 35, 50, 75, 95% 차광)을 달리하여 실시하였으며, 차광별 생장과 형태적 특성을 각각 조사하였다. 실험 결과, 곰취의 초장은 75%차광에서 17.3cm, 뿌리직경은 전광에서 2.13mm로 가장 높은 생장을 보인 것으로 조사되었다. 부위별(잎, 줄기, 뿌리) 및 전체 생체중은 모두 50% 차광에서 각각 1.784g, 1.330g, 0.791g, 3.905g으로 가장 높은 것으로 조사되었다. 건물중의 경우, 지상부(잎, 줄기)와 전체 건물중은 35% 차광에서, 뿌리는 전광에서 가장 높게 나타났다. S/R율, 부위별(잎, 줄기, 뿌리) 및 전체 함수율은 모두 95% 차광에서 가장 높은 것으로 나타났다. 엽면적은 50% 차광에서 $39.3cm^2$로 가장 높게 조사되었으며, SLA와 LAR은 차광 처리구에서 차광률이 높아질수록 증가하였다. 엽두께는 차광률이 높아질수록 얇아지는 경향을 보였다. 뿌리 특성에서는 95% 차광을 제외하고 전반적으로 좋은 생장을 보였으나 상대적으로 35~75% 차광에서 세근발달이 더 좋은 것으로 나타났다. 본 실험결과를 종합적으로 살펴보면, 곰취의 유묘는 50% 차광처리하여 생육하는 것이 포장 이식용 유묘 생산에 보다 효과적일 것으로 판단된다.

검색 효과성에 영향을 미치는 시맨틱웹 검색시스템 품질요인에 관한 연구 (Quality Dimensions Affecting the Effectiveness of a Semantic-Web Search Engine)

  • 한동일;홍일유
    • Asia pacific journal of information systems
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    • 제19권1호
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    • pp.1-31
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    • 2009
  • This paper empirically examines factors that potentially influence the success of a Web-based semantic search engine. A research model has been proposed that shows the impact of quality-related factors upon the effectiveness of a semantic search engine, based on DeLone and McLean's(2003) information systems success model. An empirical study has been conducted to test hypotheses formulated around the research model, and statistical methods were applied to analyze gathered data and draw conclusions. Implications for academics and practitioners are offered based on the findings of the study. The proposed model includes three quality dimensions of a Web-based semantic search engine-namely, information quality, system quality and service quality. These three dimensions each have measures designed to collectively assess the respective dimension. The model is intended to examine the relationship between measures of these quality dimensions and measures of two dependent constructs, including individuals' net benefit and user satisfaction. Individuals' net benefit was measured by the extent to which the user's information needs were adequately met, whereas user satisfaction was measured by a combination of the perceived satisfaction with search results and the perceived satisfaction with the overall system. A total of 23 hypotheses have been formulated around the model, and a questionnaire survey has been conducted using a functional semantic search website created by KT and Hakia, so as to collect data to validate the model. Copies of a questionnaire form were handed out in person to 160 research associates and employees working in the area of designing and developing semantic search engines. Those who received the form, 148 respondents returned valid responses. The survey form asked respondents to use the given website to answer questions concerning the system. The results of the empirical study have indicated that, of the three quality dimensions, information quality was found to have the strongest association with the effectiveness of a Web-based semantic search engine. This finding is consistent with the observation in the literature that the aspects of the information quality should serve as a basis for evaluating the search outcomes from a semantic search engine. Measures under the information quality dimension that have a positive effect on informational gratification and user satisfaction were found to be recall and currency. Under the system quality dimension, response time and interactivity, were positively related to informational gratification. On the other hand, only one measure under the service quality dimension, reliability was found to have a positive relationship with user satisfaction. The results were based on the seven hypotheses that have been accepted. One may wonder why 15 out of the 23 hypotheses have been rejected and question the theoretical soundness of the model. However, the correlations between independent variables and dependent variables came out to be fairly high. This suggests that the structural equation model yielded results inconsistent with those of coefficient analysis, because the structural equation model intends to examine the relationship among independent variables as well as the relationship between independent variables and dependent variables. The findings offer some useful implications for owners of a semantic search engine, as far as the design and maintenance of the website is concerned. First, the system should be designed to respond to the user's query as fast as possible. Also it should be designed to support the search process by recommending, revising, and choosing a search query, so as to maximize users' interactions with the system. Second, the system should present search results with maximum recall and currency to effectively meet the users' expectations. Third, it should be capable of providing online services in a reliable and trustworthy manner. Finally, effective increase in user satisfaction requires the improvement of quality factors associated with a semantic search engine, which would in turn help increase the informational gratification for users. The proposed model can serve as a useful framework for measuring the success of a Web-based semantic search engine. Applying the search engine success framework to the measurement of search engine effectiveness has the potential to provide an outline of what areas of a semantic search engine needs improvement, in order to better meet information needs of users. Further research will be needed to make this idea a reality.

난소기능평가를 위한 Gonadotropin Releasing Hormone Agonist Stimulation Test (GAST)의 효용성에 관한 연구 (GnRH Agonist Stimulation Test (GAST) for Prediction of Ovarian Response in Controlled Ovarian Stimulation (COH))

  • 김미란;송인옥;연혜정;최범채;백은찬;궁미경;손일표;이진우;강인수
    • Clinical and Experimental Reproductive Medicine
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    • 제26권2호
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    • pp.163-170
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    • 1999
  • Objectives: The aims of this study are 1) to determine if GAST is a better indicator in predicting ovarian response to COH compared with patient's age or basal FSH level and 2) to evaluate its role in detecting abnormal ovarian response. Design: Prospective study in 118 patients undergoing IVF-ET using GnRH-a short protocol during May-September 1995. Materials and Methods: After blood sampling for basal FSH and estradiol $(E_2)$ on cycle day two, 0.5ml (0.525mg) GnRH agonist ($Suprefact^{(r)}$, Hoechst) was injected subcutaneously. Serum $E_2$ was measured 24 hours later. Initial $E_2$ difference $({\Delta}E_2)$ was defined as the change in $E_2$ on day 3 over the baseline day 2 value. Sixteen patients with ovarian cyst or single ovary or incorrect blood collection time were excluded from the analysis. The patients were divided into three groups by ${\Delta}E_2$; group A (n=30):${\Delta}E_2$<40 pg/ml, group B (n=52): 40 pg/ml${\leq}{\Delta}E_2$<100 pg/ml, group C (n=20): ${\Delta}E_2{\leq}100$ pg/ml. COH was done by GnRH agonist/HMG/hCG and IVF-ET was followed. Ratio of $E_2$ on day of hCG injection over the number of ampules of gonadotropins used ($E_2hCGday$/Amp) was regarded as ovarian responsiveness. Poor ovarian response and overstimulation were defined as $E_2$ hCGday less than 600 pg/ml and greater than 5000 pg/ml, respectively. Results: Mean age $({\pm}SEM)$ in group A, B and C were $33.7{\pm}0.8^*,\;31.5{\pm}0.6\;and\;30.6{\pm}0.5^*$, respectively ($^*$: p<0.05). Mean basal FSH level of group $A(11.1{\pm}1.1mlU/ml)$ was significantly higher than those of $B(7.4{\pm}0.2mIU/ml)$ and C $(6.8{\pm}0.4mIU/ml)$ (p<0.001). Mean $E_2hCGday$ of group A was significantly lower than those of group B or C, i.e., $1402.1{\pm}187.7pg/ml,\;3153.2{\pm}240.0pg/ml,\;4078.8{\pm}306.4pg/ml$ respectively (p<0.0001). The number of ampules of gonadotropins used in group A was significantly greater than those in group B or C: $38.6{\pm}2.3,\;24.2{\pm}1.1\;and\;18.5{\pm}1.0$ (p<0.0001). The number of oocytes retrieved in group A was significantly smaller than those in group B or C: $6.4{\pm}1.1,\;15.5{\pm}1.1\;and\;18.6{\pm}1.6$, respectively (p<0.0001). By stepwise multiple regression, only ${\Delta}E_2$ showed a significant correlation (r=0.68, p<0.0001) with $E_2HCGday$/Amp, while age or basal FSH level were not significant. Likewise, only ${\Delta}E_2$ correlated significantly with the number of oocytes retrieved (r=0.57, p<0.001). All four patients whose COH was canceled due to poor ovarian response belonged to group A only (Fisher's exact test, p<0.01). Whereas none of 30 patients in group A (0%) had overstimulation, 14 patients among 72 patients (19.4%) in group B and C had overstimulation (Fisher's exact test, p<0.01). Conclusions: These data suggest that initial $E_2$ difference after GAST may be a better prognostic indicator of ovarian response to COH than age or basal FSH level. Since initial $E_2$ difference demonstrates significant association with abnormal ovarian response such as poor ovarian response necessitating cycle cancellation or overstimulation, GAST may be helpful in monitoring and consultation of patients during COH in IVF-ET cycle.

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체외수정시술시 난포자극호르몬 수용체 유전자 다형성이 과배란유도 및 임신 결과에 미치는 영향 (The Effect of Follicle-Stimulating Hormone Receptor (FSHR) Polymorphism on Outcomes of Controlled Ovarian Hyperstimulation (COH) and In-vitro Fertilization and Embryo Transfer (IVF-ET))

  • 윤지성;최영민;임경실;허창영;강영제;정재훈;이원돈;임진호;황규리;지병철;구승엽;서창석;김석현;김정구;문신용
    • Clinical and Experimental Reproductive Medicine
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    • 제31권2호
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    • pp.133-139
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    • 2004
  • Objective: To investigate the association of FSH receptor (FSHR) polymorphism at position 680 with outcomes of controlled ovarian hyper-stimulation for IVF-ET in Korean women. Design: Genetic polymorphism analysis. Materials and Methods: The FSHR polymorphism was analyzed by PCR-RFLP in 172 ovulatory women below the age of 40 year. Patients with polycystic ovary syndrome, endometriosis, or previous history of ovarian surgery were excluded. Results: Genotype distribution was 41.9% for the Asn/Asn, 47.7% for the Asn/Ser, and 10.5% for the Ser/Ser FSHR genotype group. There was no difference in age of subjects and infertility diagnosis between genotype groups. When the patients were grouped according to their FSHR genotype, the basal levels of FSH (day 3) were significantly different among the three groups ($6.0{\pm}0.3\;IU/L$ (mean $\pm$ SEM), $5.8{\pm}0.3\;IU/L$, and $8.6{\pm}1.2\;IU/L$ for the Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively, p=0.002). The Ser/Ser group showed a higher total doses of gonadotropins required to achieve ovulation induction, and a lower serum estradiol levels at the time of hCG administration compared with other two groups, but the differences were of no statistical significance. The numbers of oocytes retrieved were significantly different among the three groups ($8.6{\pm}0.8$, $9.9{\pm}0.6$, and $6.3{\pm}0.9$, for the Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively, p=0.049). Clinical pregnancy rates were 42.4%, 25.9%, and 29.4% for the Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively. Conclusion: Homozygous Ser/Ser genotype of FSHR polymorphism at position 680 was associated with decreased ovarian response to gonadotropin stimulation for IVF-ET.

완효성 질소 비료의 시비가 크리핑 벤트그래스 생장과 토양 중 질소변화에 미치는 영향 (The Effect of Compound Fertilizer Contained Slow Release Nitrogen on Turfgrass Growth in Creeping Bentgrasss and on Change in Soil Nitrogen)

  • 김영선;김택수;함선규;방수원;이창은
    • 아시안잔디학회지
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    • 제23권1호
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    • pp.111-122
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    • 2009
  • 본 연구는 완효성 질소 성분이 함유된 복합비료의 시비가 크리핑벤드그래스 생육과 토양 중 변화에 미치는 영향을 시험하고자 2007년 7월부터 12월까지 6개월간 수행하였다. 처리구는 비료를 처리하지 않은 무처리구(NF), 속효성질소복합비료(11-5-7)를 처리한 대조구(CF), MU 질소성분이 함유된 복합비료를 처리한 처리구 1(MU), IBDU 질소성분이 함유 된 복합비료를 처리한 처리구 2(IBDU 1)과 처리구3(IBDU 2) 등 5개 처리를 난괴댑으로 수행하였다. 시비 후 속효성질소성분과 완효성질소성분의 경과시간에 따른 토양 중 변화와 염색지수와 엽록소함량과 같은 잔디품질과 잔디 생육량, 잔디밀도 등 잔디 생육을 조사하였고, 그 결과를 요약하면 아래와 같다. 암모니아태질소와 질산태질소는 모든 처리구에서 시비 후 시간이 경과함에 따라 점차증가하는 경향을 보였고, 총질소는 점차 감소하였다. 질산태질소와 총질소는 속효성 비료처리구(CF)보다는 완효성 비료 처리구(MU, IBDU 1, IBDU 2)에서 높게 나타났으며, 시비 후 경과시간에 따른 토양 중 가용성질소의 변화는 시비초기에는 속효성 비료의 가용성 질소가 많으나 시비 후 30일 정도까지는 속효성 비료와 완효성 비료의 가용성 질소 비율은 비슷하고 30일 이후에는 완효성 비료 처리구에서 가용성 질소 비율이 증가하였다. 염색지수와 엽록소함량을 NF와 비교한 결과, 엽색지수는 CF, MU, IBDU 1 및 IBDU 2에서 각각 6.5%, 6.7%, 5.9%, 5.5% 증가하였고, 엽록소함량은 33.2%, 38.4%, 35.1%, 37.1% 증가하여 MU 처리구에서 높게 나타났다. 잔디생육량은 CF, MU, IBDU 1 및 IBBU 2가 NF보다 76.2%, 77.7%, 69.5%, 72.3% 각각 높게 나타났으나 대조구와 처리구간 예초물량은 비슷하였고, 잔디밀도는 무처리구보다 비료 처리구에서 증가하였고, 속효성 비료처리구(CF)보다 완효성 비료 처리구(MU, IBDU 1, IBDU 2)에서 잔디밀도가 증가했다. 본 결과들을 통해 완효성 질소 성분함유비료가 속효성 질소에 비해 토양 중 가용성 질소의 함량을 높여 질소비효기간을 연장시키고, 염색지수와 엽록소함량은 비슷하며 예초물량은 비슷하거나 감소시키지만 잔디밀도는 향상시켜 완효성질소 함유비료의 시비가 잔디생육에 효과적인 것으로 평가되었다.

도로터널 화재 시 집중배기방식의 배기포트 통과풍속이 배연성능에 미치는 영향에 관한 연구 (A study on the effect of air velocity through a damper on smoke extraction performance in case of fire in road tunnels)

  • 류지오;나광훈
    • 한국터널지하공간학회 논문집
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    • 제22권4호
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    • pp.347-365
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    • 2020
  • 도시지역의 교통난 해소와 녹지공간의 확보를 위해 도심지 터널이 증가하면서 차량의 정체 가능성이 높은 터널에 대한 제·배연방식으로 대배기구에 의한 집중배기방식의 적용이 증가하는 추세에 있다. 집중배기방식의 배연성능은 배연풍량 뿐만 아니라 배기구(댐퍼)의 형상이나 배기풍속 등 다양한 인자에 의해서 영향을 받는 것으로 알려져 있다. 이에 본 연구에서는 각국의 배연시스템 설계기준 및 설치현황을 알아보고 배연풍량이 동일한 경우에 배연댐퍼 사이즈에 따른 배연성능을 연기 이동거리 측면에서 수치시뮬레이션을 수행하여 비교·평가하였으며, 다음과 같은 결과를 얻었다. 배연댐퍼의 단면적이 증가할수록 배기팬에 근접한 댐퍼에서 배기풍량이 집중되어 화재 하류의 댐퍼의 배연풍량이 감소하여 하류측의 연기 이동거리가 증가하는 현상이 발생한다. 이와 같은 현상을 방지하기 위해서는 배연댐퍼의 단면적을 작게하여 통과풍속을 높게 함으로써 댐퍼통과 시 압력손실이 증가하도록 하여 배기구간에서 배연풍량의 불균일성을 완화할 필요가 있다. 본 해석범위에서는 배연댐퍼의 설치간격이 50 m인 경우에는 설계통과풍속이 4.4 m/s (댐퍼면적: 2.34 ㎡ = 1.25 × 1.85 m) 이상, 댐퍼의 설치간격이 100 m인 경우에는 설계통과풍속이 4.84 m/s (댐퍼면적: 3.38 ㎡ = 1.5 × 2.25 m) 이상일 때 배연성능확보에 유리한 것으로 나타났다.