• Title/Summary/Keyword: Operation history

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Evolution of Geometric Interpretation of Complex Number : Focused on Descarte, Wallis, Wessel (복소수의 기하적 해석의 발달 : Descarte, Wallis, Wessel를 중심으로)

  • Lee, Dong-Hwan
    • Journal for History of Mathematics
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    • v.20 no.3
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    • pp.59-72
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    • 2007
  • In this paper we find the germ of geometric interpretation of complex number in the Euclid Element and try to show the evolution of geometric interpretation of complex number by through Descarte, Wallis, Vessel. As a result, relations and differences between them are found. They related line with complex number and interpreted complex number geometrically by generalizing the multiplication operation.

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Mitral Valve Replacement: A Case Report (승모판막 이식수술 1례 보고)

  • 양기민
    • Journal of Chest Surgery
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    • v.4 no.1
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    • pp.51-54
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    • 1971
  • 37 years old female was admitted with chief complaints of dyspnea on exertion and hemoptysis. Past history and family history were non-contributory. Physical examination showed Grade III systolic murmur at the apex, which transmitted to the back. E. K. G. and X-ray findings were compatible with the mitral insufficiency. With small size of Beall mitral valve, mitral valve replacement was done under the cardia-pulmonary bypass using hemodilution technic. Patient was tracheotomized after operation and assisted respiration was done for four weeks. Postoperatively, all signs were fine and patient walked around the ward without any difficulty, but she was in psychotic state. On postoperative 60th day, she complained of sudden dyspnea and on chest film, tracheal stenosis was found and recannulation of the tracheal tube was made. Thereafter, she was quite fine until postoperative 110th day when she, by berself, removed the tracheal cannula and died of asphyxia. Autopsy findings of the valve showed no thrombosis, no variance of the valve, and good endothelization of the valve cuffs. Asphyxia, due to removal of the tracheal connula by herself under psychotic state, was considered to be the cause of death in this patient who had tracheal stenosis after tracheostomy.

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A Study on Changes of Pre-service Mathematics Teachers' Teaching Ability through Teaching Practicum (학교현장실습을 통한 예비수학교사들의 수업능력 변화에 대한 연구)

  • Shim, Sang Kil
    • Journal for History of Mathematics
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    • v.30 no.3
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    • pp.163-183
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    • 2017
  • In this study we reveal that there were positive changes after the practicums of pre-service math teachers, in that, they changed contents of class and the way of explanation in order to enhance students' understanding, and provided opportunities for students to participate in the class. In addition, they made more use of textbooks in their class instead of depending on their experience acquired before the practicums. However, no difference was found before and after their practicums, neither in their review of lessons nor in their use of simple 'question and answer' strategies. In this regard, we suggest continuous researches be conducted in order to enhance pre-service mathematics teachers' teaching ability, especially those which is hard to be acquired in a short period of time. And, reflecting the results of the research, systematic development and operation of the curriculum are required in the teacher training institutes.

Graphonomy research of wooden member terms in Yeonggeon-euigwe (영건의궤(營建儀軌)의 목부재(木部材) 용어(用語)에 관(關)한 문자학적(文字學的) 연구(硏究))

  • Kim, Jae-Ung
    • Journal of architectural history
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    • v.18 no.1
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    • pp.67-89
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    • 2009
  • This study examines the examples of wooden member terms of architecture terminology used in Yeonggeon-euigwe(營建儀軌) in the era of Joseon Dynasty. It is to trace the period of their appearances and changes and also to illuminate coinage characteristics and method of architectural terminology used in Yeonggeon-euigwe through graphonomy research and system and structure of wood member terms. By analyzing the meaning of a word, it was found that there was much Insineui, difference of word meaning by country was shown although it was the same shape of character. In particular, the specialty of double language system of Korean language is combined with that of wood terms. Operation of type unrelated to word meaning was found and Korean unique Gachaeui(假借義) like Bo(褓) was generated. This study draws separate systems: one is that can indicate coinage characters of architectural terminology in Yeonggeon-euigwe. The other is to obtain coinage method as a result of reclassifying terminology based on it.

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A Clinical Study of Ten Cases of Strabismus in Children by Oriental Medicine (小兒斜視 10例의 臨床的 硏究)

  • Kim, Joong-Ho
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.8 no.1
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    • pp.133-142
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    • 1995
  • The author performed in 10 cases under the age of 13 years who were visited to hospital from July 1994 to July 1995. I have assessed information such as type of deviation, detected time of strabismus, past history, family history. The most of patient were esotropia. I have experienced good improvement to recover strabismus by the Oriental Medicine. The acupuncture points of B2, TE23. S1, G14, E36 were mainly used. Herbal medicine was treated GAMIBOJOONGYKGI-TANG. It was supposed to encourage digestive system and to continue elastic capacity. From the results of this study, it is effective to change of correct position at the deviational eyeball and to treat amp1yopia with strabismus. It was reported possble to treat strabismus without operation and glasses.

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Airway anesthesia with lidocaine for general anesthesia without using neuromuscular blocking agents in a patient with a history of anaphylaxis to rocuronium: a case report

  • Ji, Sung-Mi;Song, Jaegyok;Choi, Gunhwa
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.20 no.3
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    • pp.173-178
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    • 2020
  • We experienced a case of induction of general anesthesia without using neuromuscular blocking agents (NMBAs) in a 40-year-old woman with a history of anaphylaxis immediately after the administration of anesthetics lidocaine, propofol, and rocuronium to perform endoscopic sinus surgery 2 years before. The skin test showed a positive reaction to rocuronium and cis-atracurium. We induced general anesthesia without using NMBAs after inducing airway anesthesia with lidocaine (transtracheal injection and superior laryngeal nerve block). Deep general anesthesia was maintained with end-tidal 4 vol% sevoflurane. Hypotension was treated with phenylephrine infusion. The operation condition was excellent, and patient recovered without complications after surgery. Airway anesthesia with local anesthetics may be helpful when we cannot use NMBAs for any reason, including hypersensitivity to NMBA and surgery that needs neuromuscular monitoring.

Development of Elementary Mathematics Teaching-Learning Programs for pre-Service Elementary Teacher (초등교사 양성 대학의 초등수학교육에 대한 교수-학습 프로그램 개발)

  • 신준식
    • The Mathematical Education
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    • v.42 no.4
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    • pp.453-463
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    • 2003
  • The main purpose of this paper is to develope elementary mathematics teaching-learning programs for pre-service elementary teachers. The elementary mathematics education program developed in this work is divided into two parts: One is the theory, the other is the practice. The theory deals with the foundations of mathematics, the objectives of mathematics education, the history of mathematics education in Korea, the psychology of mathematics learning, the theories of mathematics teaching and learning, and the methods of assessment. With respect to the practice, this study examines the background knowledge and activities of numbers and their operation, geometry, measurement, statistics and probability, pattern and function.

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A Study on Reliability Analysis & Determination of Replacement Cycle of the Railway Vehicle Contactor (철도차량 접촉기의 신뢰성 분석 및 교환주기 결정에 대한 연구)

  • Park, Minheung;Rhee, Sehun
    • Journal of Applied Reliability
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    • v.17 no.4
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    • pp.316-324
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    • 2017
  • Purpose: The purpose of this study is to determine the replacement cycle applied age replacement policy by reliability analysis based on railway vehicle contactor's failure history data. Method: We performed reliability analysis based on railway vehicle contactor's failure history data. We found a suitable distribution by goodness of fit test and predicted the reliability through estimation of scale & shape parameter. Considering cost information we determined the replacement cycle that minimize the opportunity cost. Result: Suitable distribution was the Weibull and scale parameter & shape parameter are estimated by reliability analysis. The replacement cycle was predicted and MTTF, $B_6$ percentile life were suggested additionally. Conclusion: We confirmed that failure rate type of railway vehicle contactor is degradation model having a time dependent characteristic and examined the replacement cycle in our country's operating environment. We expect that this study result contribute to railway operation agency for maintenance policy decision.

A 30-year neglected foreign body mimicking a maxillary fracture

  • Lee, Wang Seok;Park, Eun Soo;Kang, Sang Gue;Tak, Min Sung;Kim, Chul Han
    • Archives of Craniofacial Surgery
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    • v.20 no.3
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    • pp.195-198
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    • 2019
  • A-50-year-old male patient presented with complaint of tenderness on the left malar area after traffic accident. Our first impression on him was zygomatic fracture, we did radiologic work-up and physical examination on him. But, on the computed tomography scan, there was no fracture or discontinuity on his facial bone. The computed tomography scan was revealed a 4-cm long foreign body in left maxillary sinus with a large amount of fluid collection. After thorough history taking from him, we reveal the patient had a history of trauma 30 years back on the left zygomatic area with a chopstick. The foreign body was removed via transoral approach with the endoscopic assist. There was no complication after operation.

Implementation and Significance of Market Modernization Plan in Seoul, 1967-1973 (1967-1973년 서울의 시장 현대화계획의 시행과 의의)

  • Park, Ilhyang
    • Journal of architectural history
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    • v.30 no.1
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    • pp.19-32
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    • 2021
  • The markets are the basic urban facilities for maintaining daily life. Although the urban structure changed rapidly and the population quickly concentrated in the city, the markets remained traditional and backward. To solve various problems in the small excess markets, the Seoul Metropolitan Government had pushed ahead with the market modernization plan since 1967. The purpose of this study is to analyze the process of establishing the market modernization plan and the progress of this project, and to identify the historical meaning of this plan. The results of this study as follows; The market modernization plan aimed to modernize market operation system as well as buildings, and the Government was able to achieve its first goal by enforcing the construction of high-rise buildings, as the markets were newly built with the relatively large scaled fireproof structures. Despite its various limitations, these markets were also regarded as the model of the modern market.