• 제목/요약/키워드: Pitfall

검색결과 98건 처리시간 0.025초

초음파 수술기의 수술 효율성 향상을 위한 진동자 임피던스 측정에 따른 조직 분류 연구 (Classification of Organs Using Impedance of Ultrasonic Surgical Knife to improve Surgical Efficiency)

  • 김홍래;김성천;김광기;김영우
    • 대한의용생체공학회:의공학회지
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    • 제34권3호
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    • pp.141-147
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    • 2013
  • Ultrasonic shears is currently in wide use as an energy device for minimal invasive surgery. There is an advantage of minimizing the carbonization behavior of the tissue due to the vibrational energy transfer system of the transducer by applying a piezoelectric ceramic. However, the vibrational energy transfer system has a pitfall in energy consumption. When the movement of the forceps is interrupted by the tissue, the horn which transfers the vibrational energy of the transducer will be affected. A study was performed to recognize different tissues by measuring the impedance of the transducer of the ultrasonic shears in order to find the factor of energy consumption according to the tissue. In the first stage of the study, the voltage and current of the transducer connecting portion were measured, along with the phase changes. Subsequently, in the second stage, the impedance of the transducer was directly measured. In the final stage, using the handpiece, we grasped the tissue and observed the impedance differences appeared in the transducer To verify the proposed tissue distinguishing method, we used the handpiece to apply a force between 5N and 10N to pork while increasing the value of the impedance of the transducer from 400 ${\Omega}$.. It was found that fat and skin tissue, tendon, liver and protein all have different impedance values of 420 ${\Omega}$, 490 ${\Omega}$, 530 ${\Omega}$, and 580 ${\Omega}$, respectively. Thus, the impedance value can be used to distinguish the type of tissues grasped by the forceps. In the future study, this relationship will be used to improve the energy efficiency of ultrasonic shears.

보행성 딱정벌레류의 다양성 및 풍부도에 관한 연구 -경북 상주시 갑장산- (Diversity and Abundance of Ground-beetles (Coleoptera) in Mt. Gabjangsan, Korea)

  • 박종균;연화순;담휴착
    • 한국토양동물학회지
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    • 제8권1_2호
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    • pp.32-36
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    • 2003
  • 상주시에서 위치한 갑장산(805.7 m)을 대상으로 고도 200m부터 800m까지 100m 간격으로 7개의 시험구를 설정하여 2001년 8월부터 2001년 10월까지 당밀을 이용한 pitfall trap를 설치하여 고도별, 계절별 다양도 및 우점도 지수를 알아보았다. 그 결과 먼지벌레와, 딱정벌레과 그리고 송장벌레과에 속한 곤충들이 채집되었고, 전체 6,304개체 중 먼지 벌레과가 6,163개체로 98% 이상을 차지하였다. 고도 200m부터 700m까지 점차적으로 개체수의 증가추세를 보이다가 800m에서 급격하게 감소하였다. 고도 700m에서 심슨의 우점도지수는 0.66으로 가장 높게 나타났으며, 800m에서 0.47로 가장 낮게 나났다. 반면 심슨의 다양도 지수는 800m에서 0.53으로 가장 높게 나타났다. 계절별 우점도 및 다양도 지수는 0.54에서 0.55로 큰 차이를 발견할 수 없었으며, 과 별 다양도지수는 먼지벌레과에서 가장 높았다.

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Differences in Temporal Variation of Ground Beetle Assemblages (Coleoptera: Carabidae) between Two Well-Preserved Areas in Mt. Sobaeksan National Park

  • Jung, Jong-Kook;Suk, Sang-Wook;Kim, Byeong-Young;Hong, EuiJeong;Kim, Youngjin;Jeong, Jong-Chul
    • Journal of Forest and Environmental Science
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    • 제33권2호
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    • pp.122-129
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    • 2017
  • Understanding how future climate conditions will be impact on the biodiversity and species composition is important, because biodiversity becomes more important in environment assessment. To understand the biological changes including diversity and species composition over time (temporal variation within a year), the species diversity and composition of ground beetles were investigated in two well-preserved areas in the Sobaeksan National Park using pitfall traps. In addition, relationships between ground beetles and environmental variables were studied by considering temporal variation. We collected 2,146 ground beetle specimens representing 45 species, and individual-based rarefaction curves indicated that similar species richness was found between Geumseon Valley (GV) and Namcheon Valley (NV). The Bray-Curtis matrix comparisons between study sites were characterized by similar ground beetles sample heterogeneity, while temporal variations in abundance, species richness, and ${\beta}-diversity$ of ground beetles showed rather difference over time according to location of study sites. In GV site, minimum temperature was selected as the best predictor for abundance, species richness, and ${\beta}-diversity$ of ground beetles, while those relationships in NV site were more complicated. In conclusion, our study suggests that understanding the different response of ground beetles to climatic variables related to local habitat conditions is important to predict the effect of climate change on biological communities.

센서 패키지용 고분자 접착제의 열화 거동 분석 (Kinetic Analyses on Thermal Degradation of Epoxy Based Adhesive for Packaging Application)

  • 김영국;이윤선
    • 마이크로전자및패키징학회지
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    • 제24권1호
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    • pp.67-73
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    • 2017
  • 열중량 분석(Thermogravimetry)을 이용하여 열화시간 경과에 따른 접착 소재의 열에 대한 열화 특성을 분석하였다. 실험에는 여섯 가지의 온도 승온률에서 측정된 데이터를 이용하여 열화에 따른 동적 반응을 분석하였다. 이 데이터를 바탕으로 아레니우스 방정식을 이용하여 활성 에너지와 비례 상수 등 모델에 필요한 계수를 계산하였다. 또한 열화거동을 예측하는 방정식으로는 무게 감소에 따른 간단한 n차 방정식을 이용하였다. 구해진 예측 모델은 실험 데이터와 비교하여 검증하였다. 계산 결과 각 승온률에 따라 활성화 에너지의 크기가 다름에 따라 평균값을 사용하여 계산한 결과는 낮은 승온률인 경우에는 잘 예측하였지만 높은 승온률인 경우에는 측정값과 차이를 보였다. 이와 같은 문제를 해결하기 위해 지수함수 급수를 이용한 새로운 모델링 방법이 처음 시도되었으며 예측된 결과는 승온률에 관계없이 실험 데이터와 잘 일치하였다.

Spade-Shaped Anastomosis Following a Proximal Gastrectomy Using a Double Suture to Fix the Posterior Esophageal Wall to the Anterior Gastric Wall (SPADE Operation): Case-Control Study of Early Outcomes

  • Han, Won Ho;Eom, Bang Wool;Yoon, Hong Man;Ryu, Junsun;Kim, Young-Woo
    • Journal of Gastric Cancer
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    • 제20권1호
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    • pp.72-80
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    • 2020
  • Purpose: Proximal gastrectomy (PG) is a function-preserving surgery in cases of proximally located early-stage gastric cancer. Because gastroesophageal reflux is a major pitfall of this operation, we devised a modified esophagogastrostomy (EG) anastomosis to fix the distal part of the posterior esophageal wall to the proximal part of the anterior stomach wall to produce an anti-reflux mechanism; we named this the SPADE operation. This study aimed to show demonstrate the clinical outcomes of the SPADE operation and compare them to those of previous PG cases. Materials and Methods: Case details of 56 patients who underwent PG between January 2012 and March 2018 were retrospectively reviewed: 30 underwent conventional esophagogastrostomy (CEG) anastomosis using a circular stapler, while 26 underwent the SPADE operation. Early postoperative clinical outcome-related reflux symptoms, endoscopic findings, and postoperative complications were compared in this case-control study. Results: Follow-up endoscopy showed more frequent reflux esophagitis cases in the CEG group than in the SPADE group (30% vs. 15.3%, P=0.19). Similarly, bile reflux (26.7% vs. 7.7%, P=0.08) and residual food (P=0.01) cases occurred more frequently in the CEG group than in the SPADE group. In the CEG group, 13 patients (43.3%) had mild reflux symptoms, while 3 patients (10%) had severe reflux symptoms. In the SPADE group, 3 patients (11.5%) had mild reflux symptoms, while 1 had severe reflux symptoms (absolute difference, 31.8%; 95% confidence interval, 1.11-29.64; P=0.01). Conclusions: A novel modified EG, the SPADE operation, has the potential to decrease gastroesophageal reflux following a PG.

국내 최초 환경부 지정 논 습지 지역인 공검지의 곤충 다양성 (Insect Diversity on the Paddy Field Wetland, Gonggeom-ji, Sangju, first designed by Ministry of Environment, Korea)

  • 김명환;황정호;최은영;박진영;박종균
    • 한국습지학회지
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    • 제19권1호
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    • pp.155-163
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    • 2017
  • 본 연구는 2011년 환경부가 보호습지로 지정한 최초의 논습지인 상주 공검지에 서식하는 곤충의 다양성을 평가하기 위해 수행되었다. 채집방법은 직접찾기, 쓸어잡기와 함정트랩을 이용하였으며, 2014년도 3월~11월 중에서 4회 채집하였다. 본 연구에서 총 8목 78과 205속 227종 1,327개체가 확인되었다. 이 중 딱정벌레목이 가장 풍부했고 (42.73%), 노린재목이 두 번째로 많았다(22.47%). 이 연구에서 총 다양성지수는 6.339으로 매우 높게 나타났다. 우점도지수는 0.143, 균등도는 0.810로 나타났다. 전체적으로, 종간 경쟁이 높고 군집 안정도 또한 높다. 그러므로 공검지는 안정적이고 긍정적인 환경을 가졌다고 할 수 있다.

홍릉 숲의 곤충(개미와 지표성 딱정벌레)의 군집구조, 종다양성, 산림건강성 (Community Structure, Species Diversity of Insects (ants, ground beetles), and Forest Health in the Hongneung Forest)

  • 이철민;권태성
    • 한국산림과학회지
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    • 제102권1호
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    • pp.97-106
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    • 2013
  • 본 연구에서는 곤충군집의 특성을 이용하여 도시숲의 산림건강성 평가를 시도하였다. 이를 위해 서울도심에 위치한 홍릉 숲에서 함정트랩법으로 개미(Formicidae)와 지표성 딱정벌레(Carabidae)를 조사하여 광릉 숲의 그것과 비교하였다. 여기서 광릉 숲은 잘 보존되고 생물다양성과 자연성이 높기 때문에 산림건강성이 높을 것으로 추정하였다. 광릉 숲에 비해 홍릉 숲은 개미는 매우 많았으나, 딱정벌레는 매우 적었다. 종다양성의 경우에는 종풍부도는 광릉 숲이 높았으나, 종다양도는 홍릉 숲이 높았다. 광릉 숲에서는 소수의 숲 특이종에 의한 우점 현상이 심한데 비해, 홍릉 숲에서는 숲 특이종과 일반종이 균형을 이룸으로서 다양도가 광릉 숲에 비해 높았다. 이와 같이 홍릉 숲은 광릉 숲과는 곤충군집의 특성이 많이 달랐다.

가리왕산 지역의 개미 고도별 분포 (Altitudinal Distribution of Ants in Mt. Gariwangsan, Korea)

  • 조경연;김일권;류동표
    • 한국환경생태학회지
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    • 제34권2호
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    • pp.115-120
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    • 2020
  • 본 연구는 생물 다양성의 지표종인 개미류의 시기별 우점종 및 개체군 변동을 살펴보고, 추후 기후변화에 따른 개체군 변화의 기초자료를 확보하고자 수행되었다. 조사 기간은 2013년 6월부터 9월까지 고도별 조사 지점을 선정하고, 함정트랩을 사용하여 정방형조사법(10m×10m)으로 개미의 분포를 조사하였다. 고도별 조사 결과, 총 3아과 11속 14종 15,466개체가 채집되었다. 낮은 고도(700m)에서 13종 4,548개체의 분포가 확인되었으며, 우점종은 일본장다리개미(49.9%)로 나타났고, 중간 고도(900m)에서 8종 9,129개체가 채집되었으며, 우점종으로 극동혹개미(57.7%)의 분포가 확인되었으며, 높은 고도(1,100m)에서 10종 1,789개체가 확인되었으며, 우점종으로 코토쿠뿔개미(43.3%)가 확인되었다. 고도별로 일본장다리개미, 스미스개미, 극동혹개미는 폭넓게 분포하는 것으로 확인되었다.

Structure and Seasonal Patterns of Ground Beetles Community in Wangpi-Cheon Watershed, South Korea

  • Park, Jinyoung;Jung, Jong Kook;Cha, Jin Yeol;Choi, Jong Bong;Park, Jong Kyun
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제1권1호
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    • pp.41-51
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    • 2020
  • Ground beetle fauna of Wangpi-cheon watershed in Yeongyang-gun to Uljin-gun, Gyeongsangbuk-do was investigated from May to October in 2012. Ground beetles were collected by pitfall trapping. A total of 38 species of 20 genera belonging to 8 subfamilies were identified from 2,486 collected ground beetles. Species richness was high in Pterostichinae (16 species), Carabinae (8 species), Harpalinae (5 species), Callistinae (3 species), Nebriinae (3 species) and others (1 species). Dominant species were Synuchus cycloderus (1,025 individuals) and Aulonocarabus seishinensis seishinensis (332 individuals), Pristosia vigil (133 individuals), and Coptolabrus smaragdinus branickii (117 individuals) in order. Monthly changes in abundance of upper dominante genera Pterostichus, Aulonocarabus, Coptolabrus species and Synuchus, Pristosia, Colpodes species showed that the former had the highest number in August whereas the latter increased in June and September. The genus Pterostichus species were preferred in deciduous forest in Wangpi-cheon watershed, while the genus Synuchus species were collected in mixes forest adjacent to farmland and recreation facilities and the genera Chlaenius, Harpalus species were collected in mixes forest adjacent to farmland nearby stream. Non-metric multidimensional scaling (NMDS), ground beetles and sites could be divided into two distinct groups: St. 1, St. 2, St. 3 group and St. 4 group. Some species such as Pterostichus orientalis orientalis, P. vicinus and P. bellatrix were particularly abundant at St. 4.

의약분업 전.후 3차 진료기관 외래이용 변화 (The Change in the Outpatient Visit to Tertiary care Hospital after the Implementation of the Separation of Prescription and Drug Dispensing Policy)

  • 조동영;유승흠;손태용
    • 한국병원경영학회지
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    • 제7권1호
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    • pp.19-40
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    • 2002
  • The purpose of this study is to find out if there has been any change in the outpatient visit to tertiary care hospitals after the introduction of the new healthcare program that divides the roles of doctors and pharmacists and the reason for the change if there is any. Two tertiary care hospitals with the largest capacity of 1200 beds and two tertiary care hospitals with the lowest capacity of 600-700 beds were randomly selected. Data of the outpatient visits from March-May 2(xx), before the new healthcare system was adopted, were compared with the data from March-May 2001, after the new policy was adopted. Outpatient visits have decreased 5.8% after the new system. There has been a dramatic decrease, especially, in the department of OB-GYN and Pediatrics of tertiary hospitals. Decrease in re-visits is much higher than the first visits. Female patients decreased more than the male patients. Outpatient visits by economically active patients group aged 25-44 declined much. Tertiary hospitals in Seoul and Kyonggi Province, as well. Outpatient income of tertiary hospitals has dropped up to 14.7% due to the decline in outpatient visits and pharmaceutical income, and resell price system which in turn has caused the hospital financial deficits. While the new program has succeeded in lowering the use of antibiotics and injections, it has the pitfall of prescribing long days and expensive drugs. A full-fledged review of the system should be conducted for the establishment of the new system and I believe this study may be a useful references. Furthermore, more profound and overall studies on the chance in the patients use of hospitals are needed.

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