• 제목/요약/키워드: Whole number division

검색결과 195건 처리시간 0.026초

분수 나눗셈 스토리 문제 만들기에 관한 예비교사 지식 조사 연구 (An Analysis of Pre-service Teachers' Pedagogical Content Knowledge about Story Problem for Division of Fractions)

  • 노지화;고호경;허난
    • 한국수학교육학회지시리즈C:초등수학교육
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    • 제19권1호
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    • pp.19-30
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    • 2016
  • 본 연구는 초등 예비교사의 교사지식 중 분수 나눗셈 스토리 문제 제기(problem posing) 수행 정도를 파악하고자 하였다. 나눗셈에 관한 스토리 문제 제기 능력은 나눗셈의 개념을 실생활 맥락에서 유연하게 사용하는 능력과도 관련이 있기 때문에 초등 예비교사들이 향후 교실에서 실생활 소재를 통해 나눗셈 교수 내용을 구성하고 가르치는데 있어 중요한 능력이라 할 수 있다. 이를 위하여 초등 예비교사 135명을 대상으로 자연수 나누기 분수 문제에 대한 설문조사를 실시하고, 분석틀 기준에 따라 '수학적 정교성'과 '주요 오류 유형' 그리고 '나눗셈 연산 모델'의 세 부분으로 나누어 자료를 분석함에 따라 초등 예비교사의 나눗셈 교사 지식에 대한 시사점을 제공하였다.

HVPE 법을 활용한 GaN 성장 시 질화처리에 관한 연구 (A study on the nitridation of GaN crystal growth by HVPE method)

  • 이승훈;이주형;이희애;오누리;이성철;강효상;이성국;양재득;박재화
    • 한국결정성장학회지
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    • 제29권4호
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    • pp.149-153
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    • 2019
  • HVPE는 GaN 단결정의 제조 방법 중 하나로 빠른 성장 속도가 장점인 상업적으로 널리 사용되는 성장 방법이다. HVPE 법에 의한 GaN 단결정 성장은 여러 공정으로 이루어지며, 특히 GaN 성장 전 기판의 질화 처리는 성장되는 GaN 단결정 품질에 상당한 영향을 미친다. 본 연구에서는 사파이어 기판 위에 GaN 단결정 성장 시 기판의 질화처리가 성장되는 GaN 단결정 품질에 미치는 영향을 알아보고자 하였다. 질화 처리를 제외한 다른 성장 조건은 동일하게 하였고 질화처리 시 기판에 공급되는 가스 유량을 다양하게 변화시킨 후 GaN 박막을 성장시키고, 성장된 GaN의 표면 특성평가를 통하여, HVPE 법에서의 질화처리 효과를 고찰하여 보고자 하였다.

반도체 회사의 인적 오류 예방 활동 사례 및 검토 (A Review on the Field Activities for the Human Error Prevention in a Semiconductor Company)

  • 이용희;이용희;류재승
    • 대한인간공학회지
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    • 제30권1호
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    • pp.117-125
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    • 2011
  • While human error happens repeatedly in the semiconductor industry in Korea, which has brought a tremendous loss from manpower, welfare etc., there are limitations to human error prevention activities. When a semiconductor company introduces new machines and facilities from Japan or Germany, the companies often do not consider human factors in the design. Also, semiconductor companies are so occupied with promoting increased productivity, their attention to human errors has been pushed aside. Negative aspects of technical exchange associated with safety management are one aspect of the industry's nature. A semiconductor company recently began acknowledging on the back of TQM(Total Quality Management) that human error has a decisive effect on the safety. There are a number of uncontrollable and hard to handle event sets because the nature of these events with a human error may often be threatened or very intensive. It is strongly required that systemic studies should be performed to grasp the whole picture of a current situation for hazard factors. This study aims to examine the human error approach through the case of human error prevention field activities in a semiconductor industry compared with the activities and experience in nuclear power plants.

Exome and genome sequencing for diagnosing patients with suspected rare genetic disease

  • Go Hun Seo;Hane Lee
    • Journal of Genetic Medicine
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    • 제20권2호
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    • pp.31-38
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    • 2023
  • Rare diseases, even though defined as fewer than 20,000 in South Korea, with over 8,000 rare Mendelian disorders having been identified, they collectively impact 6-8% of the global population. Many of the rare diseases pose significant challenges to patients, patients' families, and the healthcare system. The diagnostic journey for rare disease patients is often lengthy and arduous, hampered by the genetic diversity and phenotypic complexity of these conditions. With the advent of next-generation sequencing technology and clinical implementation of exome sequencing (ES) and genome sequencing (GS), the diagnostic rate for rare diseases is 25-50% depending on the disease category. It is also allowing more rapid new gene-disease association discovery and equipping us to practice precision medicine by offering tailored medical management plans, early intervention, family planning options. However, a substantial number of patients remain undiagnosed, and it could be due to several factors. Some may not have genetic disorders. Some may have disease-causing variants that are not detectable or interpretable by ES and GS. It's also possible that some patient might have a disease-causing variant in a gene that hasn't yet been linked to a disease. For patients who remain undiagnosed, reanalysis of existing data has shown promises in providing new molecular diagnoses achieved by new gene-disease associations, new variant discovery, and variant reclassification, leading to a 5-10% increase in the diagnostic rate. More advanced approach such as long-read sequencing, transcriptome sequencing and integration of multi-omics data may provide potential values in uncovering elusive genetic causes.

Finding the Maximum Flow in a Network with Simple Paths

  • Lee, Seung-Min;Lee, Chong-Hyung;Park, Dong-Ho
    • Communications for Statistical Applications and Methods
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    • 제9권3호
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    • pp.845-851
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    • 2002
  • An efficient method is developed to obtain the maximum flow for a network when its simple paths are known. Most of the existing techniques need to convert simple paths into minimal cuts, or to determine the order of simple paths to be applied in the process to reach the correct result. In this paper, we propose a method based on the concepts of signed simple path and signed flow defined in the text. Our method involves a fewer number of arithmetic operations at each iteration, and requires fewer iterations in the whole process than the existing methods. Our method can be easily extended to a mixed network with a slight modification. Furthermore, the correctness of our method does not depend on the order of simple paths to be applied in the process.

Comparing U. S. and Taiwanese Pre-service Teachers' Solving Triangular Arithmagons

  • LIN, Cheng-Yao;KUO, Yu-Chun
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제19권2호
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    • pp.89-100
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    • 2015
  • The study investigated pre-service teachers' knowledge and computational skills by using Triangular Arithmagon. Participants included 90 pre-service teachers from two schools in the United States and Taiwan. The Triangular Arithmagons Test (TAT) was used to measure pre-service teachers' performance in whole number, fractions, and decimals operations (i.e., addition, subtraction, multiplication, and division), each of which included level-1 (basic) and level-2 (advanced) tests. MANOVA analysis was performed to compare the performance between teachers from the United States and Taiwan. Results indicated that overall, pre-service teachers in Taiwan outperformed those in the United States, especially on the advanced-level tests. Pre-service teachers in the United States were found to have poor ability of solving complex operation problems. Different curriculum plans and teaching methods may lead to the performance gap between the two countries.

기업내에서의 소집단활동의 새 방향 (Prospective to Small Group Activities of Corporate in Korea)

  • 이진근
    • 한국기술사회:학술대회논문집
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    • 한국기술사회 1984년도 제14회 한일기술사 합동 심포지움 참관기
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    • pp.77-82
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    • 1984
  • The small group activities (SGA) was introduced into some of enterprises in Korea in 1967 and plant division, Saemaul undong Headquarters had encouraged Quality Control Circles (QCC) within the manufacturing corporations in assistance of central government. Registered small groups as of august 31, 1984 amounted up to 78,243 units and the number of members were 791,512. Meanwhile, small and medium industries have mostly introduced small group activities considerably later and less actively managed than large business. Main reasons for the less effectiveness of the activities are due to lack of management skills and less awareness of it from management and workers group. Effective small group activities are presumed to be successful only with labor management cooperation on the basis of human-oriented management philosophy. The small group activities are also prevalent in service sector. More derivative methods have been developed and more members are willingly participating in training programs. The small group which is basically a horizontal organization unit, promotes communication within the whole organization. In consideration of the social circumstances and traditions, the flexible model of the small group activities suitable to the corporate environment, will contribute to industrial development.

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Sampling Study on Environmental Observations: Precipitation, Soil Moisture and Land Cover Information

  • 유철상
    • 한국환경과학회지
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    • 제5권2호
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    • pp.103-112
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    • 1996
  • Observational date is integral in our understanding of present climate, its natural variability and any cnange roue to anturopogenic effects. This study incorporates a brief overview of sampling requirements using data from the first ISLSCP Field Experiment (FIFE) in 1987, which was a multi-disciplinary field experiment over a 15km grid in Konza Prairie, USA. Sampling strategies were designed for precipitation and soil moisture measurements and also detecting land cover type. It was concludes that up to 8 raingages would be needed for valuable precipitation measurements covering the whole FIFE catchment, but only one soil moisture station. Results show that as new gages or station are added to the catchment then the sampling error is reduced, but the Improvement in error performance is less as the number of gages or stations increases. Sampling from remoteiy sensed instruments shows different results. It can be seen that the sampling error at 1arger resolution sizes are small due to competing error contribution from both commission and omission error.

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On Finding the Maximum Capacity Flow in Networks

  • Lee, Chong-Hyung;Park, Dong-Ho;Lee, Seung-Min
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2002년도 정기학술대회
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    • pp.297-302
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    • 2002
  • An efficient method is developed to obtain the maximum capacity flow for a network when its simple paths are known. Most of the existing techniques need to convert simple paths into minimal cuts, or to determine the order of simple paths to be applied in the process to reach the correct result. In this paper, we propose a method based on the concepts of signed simple path and signed flow defined in the text. Our method involves a fewer number of arithmetic operations at each iteration, and requires fewer iterations in the whole process than the existing methods. Our method can be easily extended to a mixed network with a slight modification. Furthermore, the correctness of our method does not depend on the order of simple paths to be applied in the process.

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Occurrence of Stem Rot of Disporum smilacinum Caused by Sclerotium rolfsii in Korea

  • Kwon, Jin-Hyeuk;Jee, Hyeong-Jin
    • The Plant Pathology Journal
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    • 제23권3호
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    • pp.212-214
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    • 2007
  • In 2005 and 2007, a basal stem rot of Disporum smilacinum caused by Sclerotium rolfsii occurred sporadically in a herb farm at Hamyang, Korea. The symptom initiated with water-soaking lesion and progressed into stem rot and wilt of a whole plant. Severely infected plants were blighted and died eventually. White mycelial mats appeared on the lesion at early stage and a number of sclerotia were formed on the stem near the soil line. The sclerotia were globoid in shape, 1-3 mm in size and white to brown in color. The optimum temperature for the growth and sclerotia formation was 30 on PDA and the hyphal width was measured $3-8{\mu}m$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of symptom, mycological characteristics and pathogenicity to the host plant, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the stem rot of D. smilacinum caused by S. rolfsii in Korea.