• 제목/요약/키워드: Root hai

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근본원인분석을 이용한 신뢰성 문제 해결 (Reliability Problem Solving Through Root Cause Analysis)

  • 정해성
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제16권1호
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    • pp.71-77
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    • 2016
  • Purpose: Root cause analysis (RCA) refers to any systematic process that identifies the causes that contribute to a focus event. The immediate cause of a focus event is often a symptom of underlying causes and may not truly identify the root causes that should be identified and addressed. Currently many RCA tools are available. Different investigators use different RCA tools on different issues. No standardized or commonly agreed way to analyse root causes exists. The purpose of this study is to propose the methodology of RCA process commonly useable for various issues. Methods: The methodology of RCA process is produced based on the hybrid RCA tools. The effectiveness assessment matrix of actions through the root cause candidates is presented. Results: No single RCA technique proposed has so far covered all necessary aspects. A hybrid approach which combines the best features of various techniques is proposed. The effectiveness assessment matrix helps us to identify the root cause to correct or eliminate system vulnerabilities effectively. Conclusion: This hybrid approach and effectiveness assessment matrix can provide guidance of RCA process across many industries and situations.

상악관제일대구치근단공위치에 관한 연구 (STUDY ON THE LOCATION OF APICAL FORAMEN ON UPPER AND LOWER FIRST MOLARS)

  • 김영해;선우양국
    • 대한치과의사협회지
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    • 제10권3호
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    • pp.149-153
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    • 1972
  • The apical foramen is not always found on the very tip of the root. The apical foramen may make its exit on the mesial, distal, labial or lingual side of a root slightly short of the root apex rather than at the root apex itself. The author collected 43 upper first molars and 84 lower first molars as a samples. Apical foramens were carefully checked and examined these location on each tip. (table 1) 1. About 33% to 49% of upper cases were found on extreme tip of roots and the remaining cases were on the distal side or mesial side. 2. Except distal simple canal of lower molars, approximately 40% to 50% were located on the very tip of the root. The remaining cases were on distal or mesial surface. 3. On lower distal simple canal, about 51% of cases made its exit on distal side. The remaining cases located on the tip end or mesial side.

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Studies on the Analysis of Dammarane Aglycones of Korean Ginseng

  • Lee, Wang-Kyu;Kim, Byong-Kak;Kim, Hai-Jung
    • 약학회지
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    • 제21권3호
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    • pp.163-166
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    • 1977
  • To establish a convenient quantitative method for dammarane glycosides in Korea ginseng, the ginseng roots harvested at the cultivation areas of Ga Pyeong, Geum San and Jeung Pyeong were dried, powered, extracted with methanol and hydrolyzed. The ginseng root obtained at Gang Hwa was divided into three parts: main root, laterial root and cortex, and then these were treated in the same manner as the above. The various hydrolysates thus obtained were subjected to the analysis by an instrument coupled with flame ionization detector. The results showed that panaxadiol contents in the ginsengs of the three different cultivation sites were similar. However, the lateral root of Gang Hwa ginseng was found to contain the largest amount of panaxadiol among the three parts of ginseng. This method of the analysis for panaxadiol in ginseng was found to be one with relative rapidity and ease.

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EDTA의 근관세척효과(根管洗滌效果)에 관(關)한 주사전자현미경적(走査電子顯微鏡的) 연구(硏究) (A SCANNING ELECTRON MICROSCOPIC STUDY ON THE EFFECT OF EDTA AS A CANAL IRRIGANT)

  • 이명종;김영해
    • Restorative Dentistry and Endodontics
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    • 제9권1호
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    • pp.107-114
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    • 1983
  • The purpose of this study was to observe the effect of cleansing action of irrigation solutions which was 3% $H_2O_2$ and 5% NaOCl, and 15% EDTA solution on the root canal wall. After treatment with the irrigant, each sample was dehydrated, and coated with 200~250${\circ}$A of gold, and observations were made with the use of scanning electron microscope. The results were as follows: 1. In the root canal walls irrigated with 3% $H_2O_2$ and 5% NaOCl solution without instrumentation after extirpation through barbed broach, the predentin of root canal wall was found scarely affected, and the wall was shown retaining network structure and fibrous organic matters. 2. When 15% EDTA was applied as irrigants for 60, 90 and 120 seconds after instrumentation, there was no signigicant difference of the cleansing effect of the elapsed times which were 90 and 120 seconds on the root canal wall, but in the applied time which was 120 seconds, the canal wall was the cleanest. Therefore it was thought that the most suitable application time of 15% EDTA as the irigants was 120 seconds.

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근관충전용(根管充塡用) sealer의 세포독성(細胞毒性)에 관한 연구(硏究) (A STUDY ON THE CYTOTOXICITY OF THE ROOT CANAL SEALERS)

  • 이승종;김영해
    • Restorative Dentistry and Endodontics
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    • 제16권1호
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    • pp.25-40
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    • 1991
  • Four root canal sealers, Apatite Root Sealer I and II composed mainly of hydroxyapatite/tricalciumphosphate, Sealapex containing calcium hydroxide, and Roth Sealer composed of zinc oxide - eugenol were compared on the culture of L929 fibroblasts. MIT (Methyl Thiazole Tetrazolium Bromide) colorimetric technique was used to measure the mitochondrial dehydrogenase activity. Results were as follows: 1. Hydroxyapatite/tricalcium phosphate mixed sealers were significantly less toxic compared with calcium hydroxide and zinc oxide - eugenol type sealers. High pH of the calcium hydroxide sealer and release of eugenol component from the zinc oxide - eugenol type sealer were presumed to be the cause of the toxicity of these two sealers. In no cases, there were more cytoblastic effects in hydroxyapatite/tricalcium phosphate mixed sealers compared to the control groups. 2. In all experimental groups, toxicity was decreased as dilutions were increased. However in zinc oxide-eugenol type sealer the cell activity was weakened for all dilution groups. 3. Regarding the effect of setting time, Apatite I and Sealapex were less toxic as the setting progressed. Apatite II kept constant regardless of the different time ellapsed after setting but Roth sealer revealed significantly higher toxicity for all experimental groups. 4. Comparing two different culture periods of 24 hours and 72 hours, Apatite I showed higher cell activities in longer period(72 hours) while Apatite II did not. Sealapex and Roth sealer, however, showed significantly lower cell activities in longer period.

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New Insights into Autonomic Nerve Preservation in High Ligation of the Inferior Mesenteric Artery in Laparoscopic Surgery for Colorectal Cancer

  • Yang, Xiao-Fei;Li, Guo-Xin;Luo, Guang-Heng;Zhong, Shi-Zhen;Ding, Zi-Hai
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2533-2539
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    • 2014
  • Aim: To take a deeper insight into the relationship between the root of the inferior mesenteric artery (IMA) and the autonomic nerve plexuses around it by cadaveric anatomy and explore anatomical evidence of autonomic nerve preservation in high ligation of the IMA in laparoscopic surgery for colorectal cancer. Methods: Anatomical dissection was performed on 11 formalin-fixed cadavers and 12 fresh cadavers. Anatomical evidence-based autonomic nerve preservation in high ligation of the IMA was performed in 22 laparoscopic curative resections of colorectal cancer. Results: As the upward continuation of the presacral nerves, the bilateral trunks of SHP had close but different relationships with the root of the IMA. The right trunk of SHP ran relatively far away from the root of IMA. When the apical lymph nodes were dissected close to the root of the IMA along the fascia space in front of the anterior renal fascia, the right trunk of SHP could be kept in suit under the anterior renal fascia. The left descending branches to SHP constituted a natural and constant anatomical landmark of the relationship between the root of IMA and the left autonomic nerves. Proximal to this, the left autonomic nerves surrounded the root of the IMA. Distally, the left trunk of the SHP departed from the root of IMA under the anterior renal fascia. When high ligation of the IMA was performed distal to it, the left trunk of SHP could be preserved. The distance between the left descending branches to SHP and the origin of IMA varied widely from 1.3 cm to 2.3 cm. Conclusions: The divergences of the bilateral autonomic nerve preservation around the root of the IMA may contribute to provide anatomical evidence for more precise evaluation of the optimal position of high ligation of the IMA in the future.

한국인삼 성분에 관한 연구 -제1보 전분함량, 전분의 입경분포, amylose함량 및 blue value에 대하여- (Studies on the Components of Korean Panax Ginseng C.A. Mayer -Part. I On the Content of Starch, Size Frequency Distribution of Starch Granules, Amylose Content and Blue Value-)

  • 김해중;남성희;김형수;이석건
    • 한국식품과학회지
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    • 제9권1호
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    • pp.19-23
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    • 1977
  • The variation of the amount of starch, size and shape of the starch granules, amylose content, and blue value of the starch in the Korean ginseng roots from one year old to five year old cultivated at Kumsan was studied. The results obtained were as follows; 1) The starch content of the ginseng root(dried) was increased with the age of the root; that is, 9.62% for one-year-old roots, 10.35% for two-year-old root, 15.50% for three-year-old root, 17.05% for four-year-old root, and 18.32% for five-year-old root. 2) The shape of the ginseng starch granules was round or short oval, and in the latter case the ratio of minor axis to major axis was 1 to 1.1. Diameter of the starch granules was in the range of $1.48\;{\mu}\;to\;8.14\;{\mu}$ and the most frequent granule size was $3\;{\mu}\;(32.1{\sim}35.7%)$. The number of big size starch granules was increased during the five years of growing, while, the number of small size granules was decreased. 3) The amylose content in the ginseng starch was varied with the age of the root, in the range of $53.6{\sim}70.5%$. 4. The blue value of the ginseng starch was in the range of 0.60 to 0.71.

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