• 제목/요약/키워드: Long Baseline

검색결과 495건 처리시간 0.025초

A NEW HARDWARE CORRELATOR IN KOREA: PERFORMANCE EVALUATION USING KVN OBSERVATIONS

  • Lee, Sang-Sung;Oh, Chung Sik;Roh, Duk-Gyoo;Oh, Se-Jin;Kim, Jongsoo;Yeom, Jae-Hwan;Kim, Hyo Ryoung;Jung, Dong-Gyu;Byun, Do-Young;Jung, Taehyun;Kawaguchi, Noriyuki;Shibata, Katsunori M.;Wajima, Kiyoaki
    • 천문학회지
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    • 제48권2호
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    • pp.125-137
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    • 2015
  • We report results of the performance evaluation of a new hardware correlator in Korea, the Daejeon correlator, developed by the Korea Astronomy and Space Science Institute (KASI) and the National Astronomical Observatory of Japan (NAOJ). We conduct Very Long Baseline Interferometry (VLBI) observations at 22 GHz with the Korean VLBI Network (KVN) in Korea and the VLBI Exploration of Radio Astrometry (VERA) in Japan, and correlated the aquired data with the Daejeon correlator. For evaluating the performance of the new hardware correlator, we compare the correlation outputs from the Daejeon correlator for KVN observations with those from a software correlator, the Distributed FX (DiFX). We investigate the correlated flux densities and brightness distributions of extragalactic compact radio sources. The comparison of the two correlator outputs shows that they are consistent with each other within < 8%, which is comparable with the amplitude calibration uncertainties of KVN observations at 22 GHz. We also find that the 8% difference in flux density is caused mainly by (a) the difference in the way of fringe phase tracking between the DiFX software correlator and the Daejeon hardware correlator, and (b) an unusual pattern (a double-layer pattern) of the amplitude correlation output from the Daejeon correlator. The visibility amplitude loss by the double-layer pattern is as small as 3%. We conclude that the new hardware correlator produces reasonable correlation outputs for continuum observations, which are consistent with the outputs from the DiFX software correlator.

반복유산을 경험한 환자에서 임신중 태반항원과 동종항원에 노출된 모체 림프구면역반응은 언제부터 소실되나? (When Dose Losses of Maternal Lymphocytes Response to Trophoblast Antigen or Alloantigen Occur in Women with a History of Recurrent Spontaneous Abortion?)

  • 최범채
    • Clinical and Experimental Reproductive Medicine
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    • 제25권2호
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    • pp.115-122
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    • 1998
  • The maintenance of a viable pregnancy has long been viewed as an immunological paradox. The deveolping embryo and trophoblast are immunologically foreign to the maternal immune system due to their maternally inherited genes products and tissue-specific differentiation antigens (Hill & Anderson, 1988). Therefore, speculation has arisen that spontaneous abortion may be caused by impaired maternal immune tolerance to the semiallogenic conceptus (Hill, 1990). Loss of recall antigen has been reported in immunosuppressed transplant recipients and is associated with graft survival (Muluk et al., 1991; Schulik et al., 1994). Progesterone $(10^{-5}M)$ has immunosuppressive capabilities (Szekeres-Bartho et al., 1985). Previous study showed that fertile women, but not women with unexplained recurrent abortion (URA), lose their immune response to recall antigens when pregnant (Bermas & Hill, 1997). Therefore, we hypothesized that immunosuppressive doses of progesterone may affect proliferative response of lymphocytes to trophoblast antigen and alloantigen. Proliferative responses using $^3H$-thymidine ($^3H$-TdR) incorporation of peripheral blood mononuclear cells (PBMCs) to the irradiated allogeneic periperal blood mononuclear cells as alloantigen, trophoblast extract and Flu as recall antigen, and PHA as mitogen were serially checked in 9 women who had experienced unexplained recurrent miscarriage. Progesterone vaginal suppositories (100mg b.i.d; Utrogestan, Organon) beginning 3 days after ovulation were given to 9 women with unexplained RSA who had prior evidence of Th1 immunity to trophoblast. We checked proliferation responses to conception cycle before and after progesterone supplementation once a week through the first 7 weeks of pregnancy. All patients of alloantigen and PHA had a positive proliferation response that occmed in the baseline phase. But 4 out of 9 patients (44.4%) of trophoblast antigen and Flu antigen had a positive proliferative response. The suppression of proliferation response to each antigen were started after proliferative phase and during pregnancy cycles. Our data demonstrated that since in vivo progesterone treated PBMCs suppressed more T-lymphocyte activation and $^3H$-TdR incorporation compare to PBMCs, which are not influenced by progesterone. This data suggested that it might be influenced by immunosuppressive effect of progesterone. In conclusion, progesterone may play an important immunological role in regulating local immune response in the fetal-placental unit. Furthermore, in the 9 women given progesterone during a conception cycle, Only two (22%) repeat pregnancy losses occured in these 9 women despite loss of antigen responsiveness (one chemical pregnancy loss and one loss at 8 weeks of growth which was karyotyped as a Trisomy 4). These finding suggested that pregnancy loss due to fetal aneuploidy is not associated with immunological phenomena.

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미국 멕시코만 기름유출사고에서 본 유처리제 사용의 효용성 고찰 (The Effectiveness of the Dispersant Use during the "Deepwater Horizon" Incident -REVIEW of the Proceedings from 2011 International Oil Spill Conference-)

  • 조현진;하창우
    • 해양환경안전학회지
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    • 제18권1호
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    • pp.61-65
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    • 2012
  • 바다에 기름오염 사고가 발생하면 여러 가지 방제 방법 중 물리적 회수 방법을 우선적으로 사용하고 유처리제는 최후 수단으로 고려하는 경향이 있다. 유처리제는 수중으로 기름이 신속히 분산되도록 하여 해수면으로부터 제거하는 방법이다. 해수면으로부터 신속히 기름을 제거하는데 대한 유처리제의 효용성은 널리 증명되어 왔으나 아직도 대부분의 국가들은 해양환경에 미치는 독성을 우려하여 적극적인 사용을 하지 않고 있는 실정이다. 보고된 자료에 의하면 유처리제와 혼합된 기름이 기름 그 자체보다 독성이 더 크게 나타나지 않았다. 멕시코만 기름유출 사고시 미국 정부와 BP사는 최대한 해안에 기름이 도달하지 않는데 중점을 두고 해수면뿐만 아니라 수중의 기름에 대해서도 유처리제를 사용하였다. 유처리제에 대한 순환경편익을 분석하면 유처리제를 사용함으로써 기름이 생태계에 머무는 시간이 줄어들며 장기간 노출을 예방하고 야생동물에 심각한 오염을 방지하는 효과가 있는 등 다양한 연구가 진행되고 있다. 미국 멕시코만 유류오염 사고와 같은 대규모 해양오염사고의 위험이 상존하는 우리 실정에서도 과학적 결과를 바탕으로 한 유처리제 사용의 효용성과 안전성에 대한 검토가 이루어져야 할 시점이라 사료된다.

고혈압 대상자의 지역사회 중심 사례관리 프로그램 효과 (Effects of Community-based Case Management Program for Clients with Hypertension)

  • 소애영;김윤미;김은영;김창엽;김철환;김희걸;신은영;유원섭;이꽃메;전경자
    • 대한간호학회지
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    • 제38권6호
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    • pp.822-830
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    • 2008
  • Purpose: The purpose of this study was to analyze effects of a community-based case management program for clients with hypertension living in the community. Methods: The research design was a one group pre and post-test design with 30 participants with hypertension who agreed to participate in the 8-12 week case management program provided by case managers from the National Health Insurance Corporation in 2002. Data were collected three times, before and after the case management services, and 6 months later. Outcomes included changes in blood pressure, knowledge of hypertension and daily life practices, including alcohol consumption, smoking, exercise, and medication adherence. Results: Repeated-measures ANOVA and post-hoc tests of means revealed significant differences before and after service for systolic blood pressure, daily life practices (monitoring body weight and BP, low salt and cholesterol and high vegetable diet, and stress-relief practices), and exercise. The goal for medication adherence was attained after service. Significant improvements from baseline to 6 months after service were observed in measures of salt and vegetables in diet. There were no significant differences on hypertension knowledge, alcohol consumption or smoking behavior between before service and after, and at 6 months. Conclusion: The findings provide preliminary evidence that case management intervention can have positive outcomes on BP control, daily life practices, exercise, and medication adherence for clients with hypertension. However, additional interventions are needed to sustain long-term effects.

NICU에 입원한 미숙아 어머니의 스트레스 (Study on the Perceived Stress Level of Mothers in Neonatal Intensive Care Unit)

  • 김태임
    • 혜화의학회지
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    • 제8권1호
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    • pp.865-878
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    • 1999
  • With advances in neonatal medicine, smaller and sicker infants are surviving premature birth. As these tiny patients battle for their lives, their parents also struggle with psychological consequences of an unexpected role. The birth of a sick infants has long been documented as stressful events for the parents. High stress levels may alter parents' interaction with their baby and impair their communication with health professionals, which can in turn affect parents' participation in care planning and decision making. Nursing interventions aimed at reducing the parental stress and anxiety levels during this crisis may have a positive impact on their ability to form an attatchment to their baby and make prudent decisions about his care. The planning of such interventions would be inhanced if the contributions of various factors to increased parental stress levels were identified. This descriptive study was conducted to understand the contents and degree of parental stress in the NICU during their premature's hospitalization, and to give a baseline data in developing nursing intervention program. Subjects were the 60 mother of hospitalized newborn in NICU of 2 University Hospital in Taejon City from April 1st, 1999 to June 30th, 1999, who agreed to take part in this study. The instrument used in this study were Parental Stressor Scales:NICU(PSS:NICU) developed by Miles et al.. and validated by 3 NICU practitioners and 3 child health nursing faculties. The questionnaire has 4 dimensions and 45 items; sight and sounds of NICU(5 items), babies' appearance and behavior nursing intervention(19 items), parental role alteration and relationship with their baby(10 items), health team communication(11 items). The questionnaire asks parents to rate each item on a five-point Likert type scale that ranges from "not stressful" (1) to "extremely stressfu1"(5). Total scores representing overall stress from the NICU environment are calculated by summing response to each item. A high score indicates high stress. A subscale score is calculated by summing the responses to each item in the subscale. Cronbach's ${\alpha}$ coefficients were .93. The data was analyzed as average, Frequency, Standard deviation, t-test, ANOVA, Pearson correlation coefficient by use of SPSS/PC+. The results of this study is summarized as follows ; 1. The total perceived stress level score of mothers of premature baby was slightly high($3.66{\pm}1.1$). The highest scored dimension was 'relationship with their baby and parental role change'($4.21{\pm}0.9$), and next were 'appearance and behavior of the baby'($3.92{\pm}1.1$), 'communication with health team'($3.32{\pm}1.3$), 'sight and sounds of NICU'($3.30{\pm}1.1$). 2. There were statistically significant correlation noted ; mother's perceived severity of the baby's condition(F=8.0012, P= .0125) and baby's gestational age(r = -.4724, P = .0500). In summary, information about physical environment of NICU, the mother's perceived severity of premature baby's state, maternal role change related variables and the knowledge of characteristics of premature baby must be included in nursing intervention program of mother's of premature baby in reducing the parental stress and anxiety level. It is suggested that each NICU needs to develop a nurse managed supportive care program for parents of premature baby. Also, it is suggested that there need to investigate the coping mechanism of mother of premature baby.

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정신사회재활서비스가 정신장애인의 삶의 질에 미치는 효과의 10년간 종단적 검증 (Ten-year Longitudinal Examination of the Effects of Psychosocial Rehabilitation Services on the Quality of Life for the Mentally Ill)

  • 배성우;박병선;김이영
    • 한국사회복지학
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    • 제68권3호
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    • pp.127-147
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    • 2016
  • 본 연구는 사회복귀시설의 정신사회재활서비스가 정신장애인의 삶의 질에 미치는 효과를 10년에 걸쳐 추적 조사하여 검증하는 것을 목적으로 한다. 이를 위하여 대구지역의 1개 사회복귀시설에 등록한 정신장애인들을 대상으로 유사실험설계를 활용하여 자료를 수집하였다. 실험집단은 시설의 서비스를 이용하는 정신장애인 23명으로 구성하였으며, 비교집단은 시설에 등록되어 있으나 자발적인 의사로 서비스를 이용하지 않는 정신장애인 23명으로 구성되었다. 초기측정 후 매 1년 간격으로 10년 동안 총 11회에 걸쳐 반복측정을 실시하였다. 수집된 자료는 위계적 선형모형(HLM)기법을 적용하여 분석하였다. 주요 결과는 다음과 같다. 첫째, 정신사회재활서비스는 정신장애인의 삶의 질을 높이는데 효과가 있었다. 둘째, 정신사회재활서비스의 효과성은 10년 동안 지속되고 있음을 확인할 수 있었다. 셋째, 연구기간 동안 정신장애인의 삶의 질은 볼록포물선의 궤적을 나타내며 변화하고 있음을 검증하였다. 이상의 결과를 종합하면, 사회복귀시설에서 제공한 다양한 정신사회재활서비스는 정신장애인들의 삶의 질 향상에 긍정적인 영향을 미칠 뿐 아니라 그 영향력이 10년 이상 장기적으로 지속되었다. 마지막으로 논의와 함의를 제시하였다.

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THE VLBI MONITORING PROJECT FOR 6.7 GHz METHANOL MASERS USING THE JVN/EAVN

  • SUGIYAMA, KOICHIRO;FUJISAWA, KENTA;HACHISUKA, KAZUYA;YONEKURA, YOSHINORI;MOTOGI, KAZUHITO;SAWADA-SATOH, SATOKO;MATSUMOTO, NAOKO;SAITO, YU;HIRANO, DAIKI;HAYASHI, KYONOSUKE;SHEN, ZHIQIANG;HONMA, MAREKI;HIROTA, TOMOYA;MURATA, YASUHIRO;DOI, AKIHIRO;NIINUMA, KOTARO;DODSON, RICHARD;RIOJA, MARIA;ELLINGSEN, SIMON;CHEN, XI;KIM, KEE-TAE;OGAWA, HIDEO
    • 천문학논총
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    • 제30권2호
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    • pp.645-647
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    • 2015
  • We have initiated a Very Long Baseline Interferometer (VLBI) monitoring project of 36 methanol maser sources at 6.7 GHz using the Japanese VLBI Network (JVN) and East-Asian VLBI Network (EAVN), starting in August 2010. The purpose of this project is to systematically reveal 3-dimensional (3-D) kine-matics of rotating disks around forming high-mass protostars. As an initial result, we present proper mo- tion detections for two methanol maser sources showing an elliptical spatial morphology, G 002.53+00.19 and G 006.79-00.25, which could be the best candidates associated with the disk. The detected proper motions indicate a simple rotation in G 002.53+00.19 and rotation with expansion in G 006.79-00.25, respectively, on the basis of disk model fits with rotating and expanding components. The expanding motions might be caused by the magnetic-centrifugal wind on the disk.

골연하 결손부에서 조직유도재생술의 장기적 방사선학적 변화 관찰 (Long-term radiographic evaluation of GTR treatment in intrabony defect)

  • 최미혜;박진우;서조영;이재목
    • Journal of Periodontal and Implant Science
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    • 제37권2호
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    • pp.181-192
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    • 2007
  • Periodontal surgery as part of the treatment of periodontal disease is mainly performed 1) to gain access to diseased areas for adequate cleaning; 2) to achieve pocket reduction or elimination; and 3) to restore the periodontal tissues lost through the disease; i.e., a new attachment formation of periodontal regeneration. To accomplish the latter, often referred to as the ultimate goal of periodontal therapy, a number of surgical procedures have been advocated throughout the years. Clinical studies have demonstrated that considerable gain of clinical attachment and bone can be achieved following guided tissue regeneration (GTR) therapy of intrabony defects. The aim of this study was to analyse the radiographic bone changes 2-year after GTR using a bone graft material and nonresorbable membrane. Patients attending the department of periodontics of Kyungpook National University Hospital were studied. Patients had clinical and radiographic evidence of intrabony defect(s), 33 sites of 30 patients aged 32 to 56 (mean age 45.6) were treated by GTR with a bone graft material and nonresorbable membrane. Baseline and 2-year follow-up radiographs were collected and evaluated for this study. Radiographic assessment includes a bone fill, bone crest change, defect resolution, and % of defect resolution. Pre- and post-treatment differences between variables (maxilla and mandible, defect depth, defect angle, bone graft materials) using the paired t-test were examined. We observed $2.86{\pm}1,87mm$ of bone fill, $065{\pm}0.79mm$ of crestal resorption, $3.49{\pm}2.11mm$ of defect resolution, and $44.42{\pm}19.51%$ of percentage of defect resolution. Mandible, deeper initial defect depth, narrower initial defect angle showed greater bone fill, defect resolution, and % of defect resolution. But no difference was observed between xenograft and allograft. Outcome of GTR as a therapy of intrabony defect was better than other therapy, but herein, good oral hygiene maintenance as a anti-infective treatment and periodic recall check of patients are essential.

수자원 영향평가에 활용 가능한 지역기후변화 시나리오 연구 (A study on the regional climate change scenario for impact assessment on water resources)

  • 임은순;권원태;배덕효
    • 한국수자원학회논문집
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    • 제39권12호
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    • pp.1043-1056
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    • 2006
  • 온실가스 증가로 인한 기후변화를 이해하고, 다양한 영향평가 분야에 상세한 기후정보를 제공하기 위해서 온실가스 배출 시나리오에 근거한 지역기후변화 시나리오 연구가 수행되었다. 본 연구에서는 역학적 상세화를 위하여 지역기후모델을 이용한 이중둥지격자시스템을 구축하고, 과거 30년(1971-2000)과 미래 30년(2021-2050)에 대한 시나리오를 생산하였다. 미래 시나리오에 대한 신뢰도를 확보하기 위하여, 기준 시나리오에 대한 관측과의 검증이 선행되었다. 기준 시나리오는 둥지격자의 한반도 영역뿐만 아니라 모격자의 동아시아 영역에 대하여 기온과 강수의 계절 및 경년변동성과 일빈도분포를 성공적으로 모사하였다. 또한 경계조건으로 이용된 전구모델과 비교하여 공간적인 특성뿐만 아니라 면적평균 시계열에서도 뚜렷한 오차의 감소를 나타내었다. 미래 기후변화 전망은 기준 시나리오와 미래 시나리오의 차이로부터 유도되며, 평균적인 변화뿐만 아니라 극한 기후의 빈도와 강도변화에 대한 분석이 수행되었다. 미래 시나리오에 의하면 2050년까지 한반도에서는 $2^{\circ}C$ 정도의 기온 상승과 겨울철 강수량의 뚜렷한 증가경향이 전망되었다. 본 연구는 한반도의 복잡한 지형적 특성이 반영된 고해상도 시나리오를 생산하기 위한 방법론을 제시하고, 생산된 시나리오를 이용하여 다양한 시공간 규모에 대한 기후특성을 파악하였다는데 의미가 있다.

GAMIT과 LGO를 사용한 방송궤도력과 정밀궤도력에 의한 GPS 자료 처리결과의 비교.분석 (Analysis of GPS Data between Precise Ephemeris and Broadcast Ephemeris Using GAMIT and LGO)

  • 주현승;한춘득;유연;최승필
    • 한국측량학회지
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    • 제27권6호
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    • pp.761-768
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    • 2009
  • 최근 GPS 상시관측소 자료의 이용이 각종 정보산업분야에서 날로 급증하고 있다. GPS 위치 관측값 취득에 있어서도 사용 소프트웨어별, 정밀궤도력 이용 및 시간대별에 따른 성과의 신뢰성 및 허용오차 기준 마련이 중요한 과제 중의 하나로 논의되고 있다. 이에 본 연구는 GPS 상시 관측소 자료를 이용하여 관측 시간대별, 사용 소프트웨어별, 위성궤도정보별로 분석하여 사용목적에 따른 정확도 허용한계 기준을 설정하고자 수행되었다. 장기선 GPS 관측망에서 연속관측시간대가 6시간까지는 정확도에 큰 변화의 차이가 없었으나 관측 시간대가 줄어듦에 따라 서서히 정확도가 저하되다가 3시간 연속 관측시간대부터는 정확도가 급격히 저하됨을 알 수 있었다. 관측조건은 같으나 학술용과 상용 소프트웨어를 적용하였을 경우 학술용에서는 1cm 이내의 오차가 발견되었으나 상용 프로그램의 경우 3cm에서 최대 10cm 까지의 차이가 있음을 알 수 있었다. 또한 위성궤도정보별 분석에서의 위치 관측값은 정밀궤도력과 방송궤도력에서 비슷한 차이가 발생함을 확인할 수 있었다. 이에 본 연구결과가 위치 관측값의 요구정확도에 적절하게 사용할 수 있는 기준설정의 마련에 필요한 자료를 제공할 수 있을 것으로 판단되었다.